Experimental research of flow servo-valve

Directory of Open Access Journals (Sweden)

Takosoglu Jakub

2017-01-01

Full Text Available Positional control of pneumatic drives is particularly important in pneumatic systems. Some methods of positioning pneumatic cylinders for changeover and tracking control are known. Choking method is the most development-oriented and has the greatest potential. An optimal and effective method, particularly when applied to pneumatic drives, has been searched for a long time. Sophisticated control systems with algorithms utilizing artificial intelligence methods are designed therefor. In order to design the control algorithm, knowledge about real parameters of servo-valves used in control systems of electro-pneumatic servo-drives is required. The paper presents the experimental research of flow servo-valve.

A parameter estimation for DC servo motor by using optimization process

International Nuclear Information System (INIS)

Arjoni Amir

2010-01-01

Modeling and simulation parameters of DC servo motor using Matlab Simulink software have been done. The objective to define the DC servo motor parameter estimation is to get DC servo motor parameter values (B, La, Ra, Km, J) which are significant value that can be used for actuation process of control systems. In the analysis of control systems DC the servo motor expressed by transfer function equation to make faster to be analyzed as a component of the actuator. To obtain the data model parameters and initial conditions of the DC servo motors is then carried out the processor modeling and simulation in which the DC servo motor combined with other components. To obtain preliminary data of the DC servo motor parameters as estimated venue, it is obtained from the data factory of the DC servo motor. The initial data parameters of the DC servo motor are applied for the optimization process by using nonlinear least square algorithm and minimize the cost function value so that the DC servo motors parameter values are obtained significantly. The result of the optimization process of the DC servo motor parameter values are B = 0.039881, J= 1.2608e-007, Km = 0.069648, La = 2.3242e-006 and Ra = 1.8837. (author)

Digitalni servo sistem za upravljanje infracrvenim lokatorom

OpenAIRE

Aleksandar Viličić; Mirko Jezdimirović

2009-01-01

U radu je predstavljen digitalni servo sistem sa pogonskim elektromotorom koji zamenjuje postojeći elektrohidraulički servo pogon na uređaju za upravljanje IC lokatorom, koji obezbeđuje zahtevanu tačnost pozicioniranja i praćenja sa minimalnim brzinama.

Control system for the Fermilab Master-Slave servo manipulator

International Nuclear Information System (INIS)

Ducar, R.J.

1977-01-01

A control system for the Fermilab Master-Slave servo manipulator was developed. This new system offers a significant improvement in operational performance over the extant servo design with additional emphasis on simplicity of operation and maintainability. The servo manipulator is force-reflecting in each of the seven independent bilateral motions. Master force multiplication is automatically increased as the slave force is increased to its fifty pound capacity. The design incorporates triac control of the low inertia two-phase servomotors and makes extensive use of digital circuits in the servo loops. The manipulator is utilized in servicing radioactive beam-line targeting equipment

Study of Servo Press with a Flywheel

Science.gov (United States)

Tso, Pei-Lum; Li, Cheng-Ho

The servo press with a flywheel is able to provide flexible motions with energy-saving merit, but its true potential has not been thoroughly studied and verified. In this paper, such the “hybrid-driven” servo press is focused on, and the stamping capacity and the energy distribution between the flywheel and the servomotor are investigated. The capacity is derived based on the principle of energy conservation, and a method of using a capacity percentage plane for evaluation is proposed. A case study is included to illustrate and interpret that the stamping capacity is highly dependent on the programmed punch motions, thus the capacity prediction is always necessary while applying this kind of servo press. The energy distribution is validated by blanking experiments, and the results indicate that the servomotor needs only to provide 15% to the flywheel torque, 12% of the total stamping energy. This validates that the servomotor power is significantly saved in comparison with conventional servo presses.

Synthesis of Servo Pneumatic/Hydraulic Drive

Directory of Open Access Journals (Sweden)

K D. Efremova

2017-01-01

Full Text Available Servo pneumatic and / or hydraulic drives are widely used in modern engineering and process control. The efficiency of using pneumatic / hydraulic drives depends on their parameters and characteristics. To select the optimal drive parameters, various methods are used, based on finding the minimum of the target (target or criteria function.The objective of this paper was to apply one crucial criterion (target function that provides determination of optimal parameters of the pneumatic / hydraulic drive with the translational motion of the end-effector as well as its use in the synthesis of the servo pneumatic cylinder. The article shows the form of the target function representing a set of drive parameters that do not have direct relationships with each other in a dimensionless form for the pneumatic / hydraulic drive with the translational motion of the end-effector. To calculate the parameters of the servo drive close to the optimal ones, a two-criteria LPτ search was used. As criteria, were used the decisive criterion - the proposed target function, and the power developed by the actuator of the pneumatic / hydraulic drive, which were presented in a dimensionless form. It is shown that the criterion for solution optimality is the minimum distance of the selected point in the space of the normalized criteria from the origin. This point was determined. In addition to the proposed criteria, non-formalised requirements were taken into account: actual and mass-produced components of drive, in terms of which its parameters close to the optimal ones were determined, and the maximum relative error of the obtained useful power value of the servo pneumatic drive was estimated. The paper presents design features of two types of the servo pneumatic drive created, taking into account the proposed target function, implemented according to the schemes "hidden" and "spaced apart". The experimental static characteristic of the servo pneumatic drive is

A low order adaptive control scheme for hydraulic servo systems

DEFF Research Database (Denmark)

Andersen, Torben Ole; Pedersen, Henrik Clemmensen; Bech, Michael Møller

2015-01-01

This paper deals with high-performance position control of hydraulics servo systems in general. The hydraulic servo system used is a two link robotic manipulator actuated by two hydraulic servo cylinders. A non-linear model of the hydraulic system and a Newton-Euler based model of the mechanical...

Study of Pneumatic Servo Loading System in Double-Sided Polishing

International Nuclear Information System (INIS)

Qian, N; Ruan, J; Li, W

2006-01-01

The precise double-sided polishing process is one of the main methods to get the ultra-smooth surface of workpiece. In double-sided polishing machine, a loading system is required to be able to precisely control the load superimposed on the workpiece, while the polishing is being carried out. A pneumatic servo loading system is proposed for this purpose. In the pneumatic servo system, the servo valve, which acts both the electrical to mechanical converter and the power amplifier, has a substantial influence on the performance of the loading system. Therefore a specially designed pneumatic digital servo valve is applied in the control system. In this paper, the construction of the pneumatic servo loading system in double-sided polishing machine and control strategy associated with the digital servo valve are first addressed. The mathematical model of the system established and the hardware of the pneumatic servo system is designed. Finally, the experiments are carried out by measuring the practical load on the workpiece and the quality of the surface finish. It is demonstrated that the error rate of load is less than 5% and a super-smooth surface of silicon wafer with roughness Ra 0.401 nm can be obtained

Phase-Division-Based Dynamic Optimization of Linkages for Drawing Servo Presses

Science.gov (United States)

Zhang, Zhi-Gang; Wang, Li-Ping; Cao, Yan-Ke

2017-11-01

Existing linkage-optimization methods are designed for mechanical presses; few can be directly used for servo presses, so development of the servo press is limited. Based on the complementarity of linkage optimization and motion planning, a phase-division-based linkage-optimization model for a drawing servo press is established. Considering the motion-planning principles of a drawing servo press, and taking account of work rating and efficiency, the constraints of the optimization model are constructed. Linkage is optimized in two modes: use of either constant eccentric speed or constant slide speed in the work segments. The performances of optimized linkages are compared with those of a mature linkage SL4-2000A, which is optimized by a traditional method. The results show that the work rating of a drawing servo press equipped with linkages optimized by this new method improved and the root-mean-square torque of the servo motors is reduced by more than 10%. This research provides a promising method for designing energy-saving drawing servo presses with high work ratings.

IUSThrust Vector Control (TVC) servo system

Science.gov (United States)

Conner, G. E.

1979-01-01

The IUS TVC SERVO SYSTEM which consists of four electrically redundant electromechanical actuators, four potentiometer assemblies, and two controllers to provide movable nozzle control on both IUS solid rocket motors is developed. An overview of the more severe IUS TVC servo system design requirements, the system and component designs, and test data acquired on a preliminary development unit is presented. Attention is focused on the unique methods of sensing movable nozzle position and providing for redundant position locks.

Position Control of Servo Systems Using Feed-Forward Friction Compensation

International Nuclear Information System (INIS)

Park, Min Gyu; Kim, Han Me; Shin, Jong Min; Kim, Jong Shik

2009-01-01

Friction is an important factor for precise position tracking control of servo systems. Servo systems with highly nonlinear friction are sensitive to the variation of operating condition. To overcome this problem, we use the LuGre friction model which can consider dynamic characteristics of friction. The LuGre friction model is used as a feed-forward compensator to improve tracking performance of servo systems. The parameters of the LuGre friction model are identified through experiments. The experimental result shows that the tracking performance of servo systems with higherly nonlinear friction can be improved by using feed-forward friction compensation

Dual arm master controller for a bilateral servo-manipulator

Science.gov (United States)

Kuban, Daniel P.; Perkins, Gerald S.

1989-01-01

A master controller for a mechanically dissimilar bilateral slave servo-manipulator is disclosed. The master controller includes a plurality of drive trains comprising a plurality of sheave arrangements and cables for controlling upper and lower degrees of master movement. The cables and sheaves of the master controller are arranged to effect kinematic duplication of the slave servo-manipulator, despite mechanical differences therebetween. A method for kinematically matching a master controller to a slave servo-manipulator is also disclosed.

Dual arm master controller for a bilateral servo-manipulator

International Nuclear Information System (INIS)

Kuban, D.P.; Perkins, G.S.

1989-01-01

A master controller for a mechanically dissimilar bilateral slave servo-manipulator is disclosed. The master controller includes a plurality of drive trains comprising a plurality of sheave arrangements and cables for controlling upper and lower degrees of master movement. The cables and sheaves of the master controller are arranged to effect kinematic duplication of the slave servo-manipulator, despite mechanical differences there between. A method for kinematically matching a master controller to a slave servo-manipulator is also disclosed. 13 figs

Motion control of servo cylinder using neural network

International Nuclear Information System (INIS)

Hwang, Un Kyoo; Cho, Seung Ho

2004-01-01

In this paper, a neural network controller that can be implemented in parallel with a PD controller is suggested for motion control of a hydraulic servo cylinder. By applying a self-excited oscillation method, the system design parameters of open loop transfer function of servo cylinder system are identified. Based on system design parameters, the PD gains are determined for the desired closed loop characteristics. The neural network is incorporated with PD control in order to compensate the inherent nonlinearities of hydraulic servo system. As an application example, a motion control using PD-NN has been performed and proved its superior performance by comparing with that of a PD control

Modeling of R/C Servo Motor and Application to Underactuated Mechanical Systems

Science.gov (United States)

Ishikawa, Masato; Kitayoshi, Ryohei; Wada, Takashi; Maruta, Ichiro; Sugie, Toshiharu

An R/C servo motor is a compact package of a DC geard-motor associated with a position servo controller. They are widely used in small-sized robotics and mechatronics by virtue of their compactness, easiness-to-use and high/weight ratio. However, it is crucial to clarify their internal model (including the embedded position servo) in order to improve control performance of mechatronic systems using R/C servo motors, such as biped robots or underactuted sysyems. In this paper, we propose a simple and realistic internal model of the R/C servo motors including the embedded servo controller, and estimate their physical parameters using continuous-time system identification method. We also provide a model of reference-to-torque transfer function so that we can estimate the internal torque acting on the load.

Modeling and stability of electro-hydraulic servo of hydraulic excavator

Science.gov (United States)

Jia, Wenhua; Yin, Chenbo; Li, Guo; Sun, Menghui

2017-11-01

The condition of the hydraulic excavator is complicated and the working environment is bad. The safety and stability of the control system is influenced by the external factors. This paper selects hydraulic excavator electro-hydraulic servo system as the research object. A mathematical model and simulation model using AMESIM of servo system is established. Then the pressure and flow characteristics are analyzed. The design and optimization of electro-hydraulic servo system and its application in engineering machinery is provided.

Direct drive digital servo press with high parallel control

Science.gov (United States)

Murata, Chikara; Yabe, Jun; Endou, Junichi; Hasegawa, Kiyoshi

2013-12-01

Direct drive digital servo press has been developed as the university-industry joint research and development since 1998. On the basis of this result, 4-axes direct drive digital servo press has been developed and in the market on April of 2002. This servo press is composed of 1 slide supported by 4 ball screws and each axis has linearscale measuring the position of each axis with high accuracy less than μm order level. Each axis is controlled independently by servo motor and feedback system. This system can keep high level parallelism and high accuracy even with high eccentric load. Furthermore the 'full stroke full power' is obtained by using ball screws. Using these features, new various types of press forming and stamping have been obtained by development and production. The new stamping and forming methods are introduced and 'manufacturing' need strategy of press forming with high added value and also the future direction of press forming are also introduced.

Jesuítas e Tupi: o encontro sacramental e ritual dos séculos XVI-XVII

Directory of Open Access Journals (Sweden)

Adone Agnolin

2006-06-01

Full Text Available Traduzindo os dogmas doutrinais pós-conciliares para os indígenas americanos, os missionários empreendiam uma tradução de uma tradição religiosa ocidental para uma cultura que não participava dela. Os códigos culturais daquela cultura "estranha" deviam servir para inscrever a tradição religiosa ocidental entre os indígenas. Para fazer isso, a "redução" devia corrigir os excessos (dos costumes e as ausências (de crenças dos novos catecúmenos americanos. Os excessos impunham a disciplina, enquanto as ausências reclamavam a doutrina. Nesse percurso, o hibridismo cultural decorrente de uma interpretação ritual do encontro doutrinal e sacramental reescreveu a relação com o sagrado segundo uma nova estrutura, tipicamente colonial.

Aerial Object Following Using Visual Fuzzy Servoing

OpenAIRE

Olivares Méndez, Miguel Ángel; Mondragon Bernal, Ivan Fernando; Campoy Cervera, Pascual; Mejias Alvarez, Luis; Martínez Luna, Carol Viviana

2011-01-01

This article presents a visual servoing system to follow a 3D moving object by a Micro Unmanned Aerial Vehicle (MUAV). The presented control strategy is based only on the visual information given by an adaptive tracking method based on the color information. A visual fuzzy system has been developed for servoing the camera situated on a rotary wing MAUV, that also considers its own dynamics. This system is focused on continuously following of an aerial moving target object, maintai...

Vision servo of industrial robot: A review

Science.gov (United States)

Zhang, Yujin

2018-04-01

Robot technology has been implemented to various areas of production and life. With the continuous development of robot applications, requirements of the robot are also getting higher and higher. In order to get better perception of the robots, vision sensors have been widely used in industrial robots. In this paper, application directions of industrial robots are reviewed. The development, classification and application of robot vision servo technology are discussed, and the development prospect of industrial robot vision servo technology is proposed.

CLFs-based optimization control for a class of constrained visual servoing systems.

Science.gov (United States)

Song, Xiulan; Miaomiao, Fu

2017-03-01

In this paper, we use the control Lyapunov function (CLF) technique to present an optimized visual servo control method for constrained eye-in-hand robot visual servoing systems. With the knowledge of camera intrinsic parameters and depth of target changes, visual servo control laws (i.e. translation speed) with adjustable parameters are derived by image point features and some known CLF of the visual servoing system. The Fibonacci method is employed to online compute the optimal value of those adjustable parameters, which yields an optimized control law to satisfy constraints of the visual servoing system. The Lyapunov's theorem and the properties of CLF are used to establish stability of the constrained visual servoing system in the closed-loop with the optimized control law. One merit of the presented method is that there is no requirement of online calculating the pseudo-inverse of the image Jacobian's matrix and the homography matrix. Simulation and experimental results illustrated the effectiveness of the method proposed here. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Dreams of pneumatic servo and rail way cars in 2010; 2010 nen noyume kukiatsu servo to tetsudo sharyo

Energy Technology Data Exchange (ETDEWEB)

Sasaki, K. [Tokyo Precision Instruments Co. Ltd., Kanagawa (Japan)

2000-01-15

This paper describes pneumatic servo and railway cars. The comfort of railway cars is improved by reducing excess transverse centrifugal force, and longitudinal, transverse and vertical vibration. Pneumatic system plays a large role in the comfort. Pneumatic system is used for doors because of certain open/shut operation and protecting a hand caught in a door from excess tightening pressure. Pneumatic system is also used for mechanical brakes. Pneumatic spring for car suspensions improves the comfort considerably. The orifice and auxiliary tank of a pneumatic spring reduce a spring constant, and give damping to the vibration system of car bodies and springs. To reduce an outward excess centrifugal force by tilting a car body inward at curve, a body tilting equipment is used which is adopted for a pendulum car with pneumatic servo control, and a tilting car with height control of both side pneumatic springs. For transverse damping, semi-active equipment using oil damper is in wide use, while that using pneumatic servo is also in rial use. (NEDO)

Inducement of Design Parameters for Reliability Improvement of Servo Actuator for Hydraulic Valve Operation

Energy Technology Data Exchange (ETDEWEB)

Sung, Baek Ju; Kim, Do Sik [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

2014-05-15

The precision hydraulic valve is widely used in various industrial field like aircraft, automobile, and general machinery. Servo actuator is the most important device for driving the precise hydraulic valve. The reliable operation of servo actuator effects on the overall hydraulic system. The performance of servo actuator relies on frequency response and step response according to arbitrary input signal. In this paper, we performed the analysis for the components of servo actuator to satisfy the reliable operation and response characteristics through the reliability analysis, and also induced the design parameters to realize the reliable operation and fast response characteristics of servo actuator for hydraulic valve operation through the empirical knowledge of experts and electromagnetic theories. We suggested the design equations to determine the values of design parameters of servo actuator as like bobbin size, length of yoke and plunger and turn number of coil, and verified the achieved design values through FEM analysis and performance tests using some prototypes of servo actuators adapted in hydraulic valve.

Servo Platform Circuit Design of Pendulous Gyroscope Based on DSP

Science.gov (United States)

Tan, Lilong; Wang, Pengcheng; Zhong, Qiyuan; Zhang, Cui; Liu, Yunfei

2018-03-01

In order to solve the problem when a certain type of pendulous gyroscope in the initial installation deviation more than 40 degrees, that the servo platform can not be up to the speed of the gyroscope in the rough north seeking phase. This paper takes the digital signal processor TMS320F28027 as the core, uses incremental digital PID algorithm, carries out the circuit design of the servo platform. Firstly, the hardware circuit is divided into three parts: DSP minimum system, motor driving circuit and signal processing circuit, then the mathematical model of incremental digital PID algorithm is established, based on the model, writes the PID control program in CCS3.3, finally, the servo motor tracking control experiment is carried out, it shows that the design can significantly improve the tracking ability of the servo platform, and the design has good engineering practice.

Designing compensator of dual servo system for high precision positioning

International Nuclear Information System (INIS)

Choi, Hyeun Seok; Song, Chi Woo; Han, Chang Soo; Choi, Tae Hoon; Lee, Nak Kyu; Na, Kyung Hwan

2003-01-01

The high precision positioning mechanism is used in various industrial fields. It is used in semiconductor manufacturing line, test instrument, bioengineering, and MEMS and so on. This paper presents a positioning mechanism with dual servo system. Dual servo system consists of a coarse stage and a fine motion stage. The course stage is driven by VCM and the actuator of fine stage is the PZT. The purposes of dual servo system are stability, higher bandwidth, and robustness. Lead compensator is applied to this control system, and is designed by PQ method. Designed compensator can improve property of positioning mechanism

Electrical servo actuator bracket. [fuel control valves on jet engines

Science.gov (United States)

Sawyer, R. V. (Inventor)

1981-01-01

An electrical servo actuator is mounted on a support arm which is allowed to pivot on a bolt through a fixed mounting bracket. The actuator is pivotally connected to the end of the support arm by a bolt which has an extension allowed to pass through a slot in the fixed mounting bracket. An actuator rod extends from the servo actuator to a crank arm which turns a control shaft. A short linear thrust of the rod pivots the crank arm through about 90 for full-on control with the rod contracted into the servo actuator, and full-off control when the rod is extended from the actuator. A spring moves the servo actuator and actuator rod toward the control crank arm once the actuator rod is fully extended in the full-off position. This assures the turning of the control shaft to a full-off position. A stop bolt and slot are provided to limit pivot motion. Once fully extended, the spring pivots the motion.

Experimental evaluation of control strategies for hydraulic servo robot

DEFF Research Database (Denmark)

Bech, Michael Møller; Andersen, Torben Ole; Pedersen, Henrik C.

2013-01-01

In this paper different linear and non-linear controllers applied to a hydraulically driven servo robot are evaluated and validated. The task is to make the actuators of the manipulator track a position reference with minimum error. Hydraulic systems are intrinsically non-linear and using linear...... in industrial servo drives. The different controllers are compared and evaluated from simulation and experimental results....

Rancang Bangun Graphical User Interface Untuk Pergerakan Motor Servo menggunakan Microsoft Visual Basic 2010 Express

Directory of Open Access Journals (Sweden)

Anggoro S Pramudyo

2016-03-01

Full Text Available Zaman sekarang ini teknologi sedang berkembang pesat dan robot-robot dirancang untuk dapat membantu pekerjaan dan tugas-tugas manusia. Motor servo merupakan salah satu jenis dari motor DC dan banyak diaplikasikan pada dunia robotik maupun peralatan lain, contohnya motor servo yang digunakan untuk robot berkaki. Dalam penggunaannya motor servo dapat bergerak karena ada sinyal yang dibangkitkan melalui sinyal PWM. Sinyal yang dihasilkan akan membentuk sudut sesuai nilai yang diberikan. Penelitian ini bertujuan untuk membuat perangkat lunak GUI untuk membuat pergerakan motor servo menggunakan Microsoft Visual Basic dengan bantuan database menggunakan Microsoft Access. Pergerakan motor servo dapat bergerak secara sekuen dan real time menggunakan GUI yang dihubungkan dengan Arduino mega 2560. Parameter yang terdapat di dalam database juga bisa langsung di-export menjadi file Arduino. Hasil penelitian ini GUI yang telah dibuat dapat menggerakkan motor servo secara lancar melalui komunikasi serial ketika baudrate diatur pada kecepatan 9600 bps. GUI yang dibuat juga menghasilkan sudut untuk motor servo yaitu dari 00 sampai 1800 secara tepat dan akurat, sehingga mempercepat waktu dalam  menentukan sudut untuk pergerakan motor servo yang akan digunakan.

Modelling and LPV control of an electro-hydraulic servo system

NARCIS (Netherlands)

Naus, G.J.L.; Wijnheijmer, F.P.; Post, W.J.A.E.M.; Steinbuch, M.; Teerhuis, A.P.

2006-01-01

This paper aims to show the modelling and control of an hydraulic servo system, targeting at frequency domain based controller design and the implementation of a LPV controller. The actual set-up consists of a mass, moved by a hydraulic cylinder and an electro-hydraulic servo valve. A nonlinear

Espaço de representação e territorialidade do sagrado: notas para uma teoria do fato religioso

Directory of Open Access Journals (Sweden)

Sylvio Fausto GIL FILHO

1999-12-01

Full Text Available As relações entre o fato religioso e o território revelam-se por meio da ruptura qualitativa do sagrado e da prática institucional da religião que se apresenta com um sistema de símbolos no qual circula o poder. Torna-se necessário resgatar a espacialidade e redimensioná-la sob a ótica do devir da sociedade.

Gloriosos pois fingidos: o esvaimento dos deuses e o consílio marítimo D’os Lusíadas

Directory of Open Access Journals (Sweden)

Luis Maffei

2015-01-01

Full Text Available Um dos aspectos mais importantes d’Os Lusíadas é a função desempenhada pelos deuses, especialmente Baco e Vênus, agentes centrais da ação em diversos momentos. Como o poema não é um épico clássico, insere-se num tempo histórico no qual, assim como nossa contemporaneidade, os deuses já não eram pertencentes ao sagrado, mas a um imaginário ficcional. Entender o poder dos deuses a partir de sua esvaziamento religioso é tarefa deste ensaio, que dialoga com dois textos recentes para afirmar não apenas a contemporaneidade de Camões, mas sua capacidade crítica: um verbete de Luís de Oliveira e Silva e um estudo de Luiza Nóbrega, ambos sobre o Consílio Marítimo do Canto VI, momento decisivo para as destinações de sentido de Baco e dos demais seres divinos de poema.

Analogical study of the servo-control of a reactivity modulator

International Nuclear Information System (INIS)

Le Bot, Michel

1969-03-01

In the context of the study of the transfer functions related to the Cabri reactor, this paper presents: the objective of the servo-control (reactivity modulator, reasons for the analogical study), the principles of the servo-control (description of the servo-controlled system, elaboration of the error signal, principles of the phase meter, critical analysis of different types of phase meters), the analogical formulation (transfer diagram of the process, analogical simulation of the process, analogical realization of the phase meter, simulation of the Low Frequency generator), study of the controlled system and results (system responses to echelon and ramp signals, responses of the controlled system with the phase meter in feedback)

The performance and limitations of FPGA-based digital servos for atomic, molecular, and optical physics experiments.

Science.gov (United States)

Yu, Shi Jing; Fajeau, Emma; Liu, Lin Qiao; Jones, David J; Madison, Kirk W

2018-02-01

In this work, we address the advantages, limitations, and technical subtleties of employing field programmable gate array (FPGA)-based digital servos for high-bandwidth feedback control of lasers in atomic, molecular, and optical physics experiments. Specifically, we provide the results of benchmark performance tests in experimental setups including noise, bandwidth, and dynamic range for two digital servos built with low and mid-range priced FPGA development platforms. The digital servo results are compared to results obtained from a commercially available state-of-the-art analog servo using the same plant for control (intensity stabilization). The digital servos have feedback bandwidths of 2.5 MHz, limited by the total signal latency, and we demonstrate improvements beyond the transfer function offered by the analog servo including a three-pole filter and a two-pole filter with phase compensation to suppress resonances. We also discuss limitations of our FPGA-servo implementation and general considerations when designing and using digital servos.

The performance and limitations of FPGA-based digital servos for atomic, molecular, and optical physics experiments

Science.gov (United States)

Yu, Shi Jing; Fajeau, Emma; Liu, Lin Qiao; Jones, David J.; Madison, Kirk W.

2018-02-01

In this work, we address the advantages, limitations, and technical subtleties of employing field programmable gate array (FPGA)-based digital servos for high-bandwidth feedback control of lasers in atomic, molecular, and optical physics experiments. Specifically, we provide the results of benchmark performance tests in experimental setups including noise, bandwidth, and dynamic range for two digital servos built with low and mid-range priced FPGA development platforms. The digital servo results are compared to results obtained from a commercially available state-of-the-art analog servo using the same plant for control (intensity stabilization). The digital servos have feedback bandwidths of 2.5 MHz, limited by the total signal latency, and we demonstrate improvements beyond the transfer function offered by the analog servo including a three-pole filter and a two-pole filter with phase compensation to suppress resonances. We also discuss limitations of our FPGA-servo implementation and general considerations when designing and using digital servos.

Optimum back-pressure forging using servo die cushion

OpenAIRE

Kawamoto, Kiichiro; Yoneyama, Takeshi; Okada, Masato; Kitayama, Satoshi; Chikahisa, Junpei

2014-01-01

This study focused on utilizing a servo die cushion (in conjunction with a servo press) as a "back-pressure load generator," to determine its effect on shape accuracy of the formed part and total forming load in forward extrusion during cold forging. The effect of back-pressure load application was confirmed in experiments, and the optimum setting pattern of back-pressure load was considered to minimize both shape accuracy of the formed part and back-pressure energy, which was representative ...

Precision position control of servo systems using adaptive back-stepping and recurrent fuzzy neural networks

International Nuclear Information System (INIS)

Kim, Han Me; Kim, Jong Shik; Han, Seong Ik

2009-01-01

To improve position tracking performance of servo systems, a position tracking control using adaptive back-stepping control(ABSC) scheme and recurrent fuzzy neural networks(RFNN) is proposed. An adaptive rule of the ABSC based on system dynamics and dynamic friction model is also suggested to compensate nonlinear dynamic friction characteristics. However, it is difficult to reduce the position tracking error of servo systems by using only the ABSC scheme because of the system uncertainties which cannot be exactly identified during the modeling of servo systems. Therefore, in order to overcome system uncertainties and then to improve position tracking performance of servo systems, the RFNN technique is additionally applied to the servo system. The feasibility of the proposed control scheme for a servo system is validated through experiments. Experimental results show that the servo system with ABS controller based on the dual friction observer and RFNN including the reconstruction error estimator can achieve desired tracking performance and robustness

Photoelectric radar servo control system based on ARM+FPGA

Science.gov (United States)

Wu, Kaixuan; Zhang, Yue; Li, Yeqiu; Dai, Qin; Yao, Jun

2016-01-01

In order to get smaller, faster, and more responsive requirements of the photoelectric radar servo control system. We propose a set of core ARM + FPGA architecture servo controller. Parallel processing capability of FPGA to be used for the encoder feedback data, PWM carrier modulation, A, B code decoding processing and so on; Utilizing the advantage of imaging design in ARM Embedded systems achieves high-speed implementation of the PID algorithm. After the actual experiment, the closed-loop speed of response of the system cycles up to 2000 times/s, in the case of excellent precision turntable shaft, using a PID algorithm to achieve the servo position control with the accuracy of + -1 encoder input code. Firstly, This article carry on in-depth study of the embedded servo control system hardware to determine the ARM and FPGA chip as the main chip with systems based on a pre-measured target required to achieve performance requirements, this article based on ARM chip used Samsung S3C2440 chip of ARM7 architecture , the FPGA chip is chosen xilinx's XC3S400 . ARM and FPGA communicate by using SPI bus, the advantage of using SPI bus is saving a lot of pins for easy system upgrades required thereafter. The system gets the speed datas through the photoelectric-encoder that transports the datas to the FPGA, Then the system transmits the datas through the FPGA to ARM, transforms speed datas into the corresponding position and velocity data in a timely manner, prepares the corresponding PWM wave to control motor rotation by making comparison between the position data and the velocity data setted in advance . According to the system requirements to draw the schematics of the photoelectric radar servo control system and PCB board to produce specially. Secondly, using PID algorithm to control the servo system, the datas of speed obtained from photoelectric-encoder is calculated position data and speed data via high-speed digital PID algorithm and coordinate models. Finally, a

Servo control booster system for minimizing following error

Science.gov (United States)

Wise, W.L.

1979-07-26

A closed-loop feedback-controlled servo system is disclosed which reduces command-to-response error to the system's position feedback resolution least increment, ..delta..S/sub R/, on a continuous real-time basis, for all operational times of consequence and for all operating speeds. The servo system employs a second position feedback control loop on a by exception basis, when the command-to-response error greater than or equal to ..delta..S/sub R/, to produce precise position correction signals. When the command-to-response error is less than ..delta..S/sub R/, control automatically reverts to conventional control means as the second position feedback control loop is disconnected, becoming transparent to conventional servo control means. By operating the second unique position feedback control loop used herein at the appropriate clocking rate, command-to-response error may be reduced to the position feedback resolution least increment. The present system may be utilized in combination with a tachometer loop for increased stability.

Provision of servo-controlled cooling during neonatal transport.

Science.gov (United States)

Johnston, Ewen D; Becher, Julie-Clare; Mitchell, Anne P; Stenson, Benjamin J

2012-09-01

Therapeutic hypothermia is a time critical intervention for infants who have experienced a hypoxic-ischaemic event. Previously reported methods of cooling during transport do not demonstrate the same stability achieved in the neonatal unit. The authors developed a system which allowed provision of servo-controlled cooling throughout transport, and present their first year's experience. Retrospective review of routinely collected patient data. 14 out-born infants were referred for cooling during a 12-month period. Nine infants were managed with the servo-controlled system during transport. Cooling was commenced in all infants before 6 h of life. Median time from team arrival to the infant having a temperature in the target range (33-34°C) was 45 min. Median temperature during transfer was 33.5°C (range 33-34°C). Temperature on arrival at the cooling centre ranged from 33.4°C to 33.8°C. Servo-controlled cooling during transport is feasible and provides an optimal level of thermal control.

Permanent magnet synchronous motor servo system control based on μC/OS

Science.gov (United States)

Shi, Chongyang; Chen, Kele; Chen, Xinglong

2015-10-01

When Opto-Electronic Tracking system operates in complex environments, every subsystem must operate efficiently and stably. As a important part of Opto-Electronic Tracking system, the performance of PMSM(Permanent Magnet Synchronous Motor) servo system affects the Opto-Electronic Tracking system's accuracy and speed greatly[1][2]. This paper applied embedded real-time operating system μC/OS to the control of PMSM servo system, implemented SVPWM(Space Vector Pulse Width Modulation) algorithm in PMSM servo system, optimized the stability of PMSM servo system. Pointing on the characteristics of the Opto-Electronic Tracking system, this paper expanded μC/OS with software redundancy processes, remote debugging and upgrading. As a result, the Opto- Electronic Tracking system performs efficiently and stably.

Research Based on AMESim of Electro-hydraulic Servo Loading System

Science.gov (United States)

Li, Jinlong; Hu, Zhiyong

2017-09-01

Electro-hydraulic servo loading system is a subject studied by many scholars in the field of simulation and control at home and abroad. The electro-hydraulic servo loading system is a loading device simulation of stress objects by aerodynamic moment and other force in the process of movement, its function is all kinds of gas in the lab condition to analyze stress under dynamic load of objects. The purpose of this paper is the design of AMESim electro-hydraulic servo system, PID control technology is used to configure the parameters of the control system, complete the loading process under different conditions, the optimal design parameters, optimization of dynamic performance of the loading system.

Stepping Motor - Hydraulic Motor Servo Drives for an NC Milling ...

African Journals Online (AJOL)

In this paper the retrofit design of the control system of an NC milling machine with a stepping motor and stepping motor - actuated hydraulic motor servo mechanism on the machines X-axis is described. The servo designed in the course of this study was tested practically and shown to be linear - the velocity following errors ...

Analysis of the servo-spill control for slow beam extraction

International Nuclear Information System (INIS)

Sato, Hikaru; Toyama, Takeshi; Marutsuka, Katsumi; Shirakata, Masashi.

1994-01-01

This report describes an analysis of servo-spill control system for the slow beam extraction from the KEK PS. Transfer function of extraction process is derived from measurement of the closed-loop characteristic using measured frequency response of each equipment. Result indicates the restriction of the present servo-spill control and give a guide line for the improvement. (author)

Nonlinear friction model for servo press simulation

Science.gov (United States)

Ma, Ninshu; Sugitomo, Nobuhiko; Kyuno, Takunori; Tamura, Shintaro; Naka, Tetsuo

2013-12-01

The friction coefficient was measured under an idealized condition for a pulse servo motion. The measured friction coefficient and its changing with both sliding distance and a pulse motion showed that the friction resistance can be reduced due to the re-lubrication during unloading process of the pulse servo motion. Based on the measured friction coefficient and its changes with sliding distance and re-lubrication of oil, a nonlinear friction model was developed. Using the newly developed the nonlinear friction model, a deep draw simulation was performed and the formability was evaluated. The results were compared with experimental ones and the effectiveness was verified.

Imaged-Based Visual Servo Control for a VTOL Aircraft

Directory of Open Access Journals (Sweden)

Liying Zou

2017-01-01

Full Text Available This paper presents a novel control strategy to force a vertical take-off and landing (VTOL aircraft to accomplish the pinpoint landing task. The control development is based on the image-based visual servoing method and the back-stepping technique; its design differs from the existing methods because the controller maps the image errors onto the actuator space via a visual model which does not contain the depth information of the feature point. The novelty of the proposed method is to extend the image-based visual servoing technique to the VTOL aircraft control. In addition, the Lyapunov theory is used to prove the asymptotic stability of the VTOL aircraft visual servoing system, while the image error can converge to zero. Furthermore, simulations have been also conducted to demonstrate the performances of the proposed method.

Mathematical-model study of servo system with pulse-duration control of micromovements

International Nuclear Information System (INIS)

Dement'eva, M.A.; Leonov, A.P.; Popov, V.V.; Skugarevskii, A.I.; Ustinov, E.A.; Chernyavskii, N.N.

1988-01-01

A number of digital servo systems with pulse-duration control have been developed at the Institute of High Energy Physics for the instruments of the scanning and measurement system and various experimental setups. They are based on stock transistor bridge stages, whose loads are high-speed servomotors with printed-circuit armature windings. Study of these servo systems by traditional methods, which are based on Laplace transforms, or by mean values with expansion of the current pulse into a Fourier transform yields approximate results and does not reflect the actual processes that take place in a pulse servo system. They attempt to develop a method and extend it to the study of high-speed servo systems in the area of micromovements and quasistationary velocity without position or velocity feedback

An open source digital servo for atomic, molecular, and optical physics experiments

Energy Technology Data Exchange (ETDEWEB)

Leibrandt, D. R., E-mail: david.leibrandt@nist.gov; Heidecker, J. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

2015-12-15

We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of {sup 27}Al{sup +} in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser.

An open source digital servo for atomic, molecular, and optical physics experiments

International Nuclear Information System (INIS)

Leibrandt, D. R.; Heidecker, J.

2015-01-01

We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of 27 Al + in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser

An open source digital servo for atomic, molecular, and optical physics experiments

Science.gov (United States)

Leibrandt, D. R.; Heidecker, J.

2015-12-01

We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of 27Al+ in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser.

Application of AC servo motor on the in-core neutron flux instrumentation system

International Nuclear Information System (INIS)

Du Xiaoguang; Wang Mingtao

2010-01-01

The application of ac servo motor in the In-Core Neutron Flux Instrumentation System is described. The hardware component of ac servo motor control system is different from the dc motor control system. The effect of two control system on the instrumentation system is compared. The ac servo motor control system can improve the accuracy of the motion control, optimize the speed control and increase the reliability. (authors)

A Design Method of Robust Servo Internal Model Control with Control Input Saturation

OpenAIRE

山田, 功; 舩見, 洋祐

2001-01-01

In the present paper, we examine a design method of robust servo Internal Model Control with control input saturation. First of all, we clarify the condition that Internal Model Control has robust servo characteristics for the system with control input saturation. From this consideration, we propose new design method of Internal Model Control with robust servo characteristics. A numerical example to illustrate the effectiveness of the proposed method is shown.

Analysis of a biphase-based servo format for hard-disk drives

NARCIS (Netherlands)

Makinwa, K.A.A.; Bergmans, J.W.M.; Voorman, J.O.

2000-01-01

Biphase modulation in an embedded-servo format for hard-disk drives is investigated. It is shown that for biphase, at the low linear densities typical of servo information, near-maximum-likelihood performance can be attained by a simple bit detector consisting of a full-response linear equalizer and

Fuzzy model-based servo and model following control for nonlinear systems.

Science.gov (United States)

Ohtake, Hiroshi; Tanaka, Kazuo; Wang, Hua O

2009-12-01

This correspondence presents servo and nonlinear model following controls for a class of nonlinear systems using the Takagi-Sugeno fuzzy model-based control approach. First, the construction method of the augmented fuzzy system for continuous-time nonlinear systems is proposed by differentiating the original nonlinear system. Second, the dynamic fuzzy servo controller and the dynamic fuzzy model following controller, which can make outputs of the nonlinear system converge to target points and to outputs of the reference system, respectively, are introduced. Finally, the servo and model following controller design conditions are given in terms of linear matrix inequalities. Design examples illustrate the utility of this approach.

In Conexione: a imaginação do sagrado na ciberarte de Diana Domingues

Directory of Open Access Journals (Sweden)

Leila Amaral

2008-06-01

Full Text Available Tendo como referência os trabalhos da artista plástica Diana Domingues será apresentada uma reflexão sobre a imaginação do sagrado nas artes visuais a partir da interpretação de temas, imagens, materiais e categorias formais que sustentam a linguagem contemporânea quando se trata do corpo em sua relação com as novas tecnologias comunicacionais. O foco da interpretação oferecida recairá sobre o sentido de sagrado (ou daquilo que é espiritual na "arte interativa" dessa artista. Tal sentido refere-se a um estado de comunicação e conectividade ampliada responsável pela expansão da consciência humana, a partir da experimentação pelo corpo da desestabilização de mundos fixos e acabados propiciada pelas novas tecnologias. O que é espiritual e sagrado para essa vertente artística é a "não essencialidade" da vida e do ser humano ou vida como "pura conectividade". É justo isso que se torna aparente através de suas "obras-dispositivos". Por meio delas, a artista explora ritual, performática e esteticamente a capacidade interativa das novas tecnologias na criação de ambientes vivos e na visualização da vida não como ela é, mas como ela pode ser. O que é sagrado é esse poder recebido das tecnologias que, ao serem acionadas por meio da conectividade, fazem aparecer a própria potência humana de intervir no mundo real e de alterar o ambiente. Não é a tecnologia em si mesma que é sagrada, mas a expansão do universo paralela à expansão da consciência por ela possibilitada, através da ampliação das conexões entre sistemas diferentes. O que é espiritual é, então, esse estado constante de transformação da consciência e da criatividade humana para além da subjetividade individual, porque, segundo essa vertente artística, os poderes recebidos pelas novas tecnologias são eles mesmos da ordem do "ultra-humano", de um "sujeito impessoal ultra-subjetivo".Based on the work of the Brazilian plastic artist Diana

Active-passive hybrid piezoelectric actuators for high-precision hard disk drive servo systems

Science.gov (United States)

Chan, Kwong Wah; Liao, Wei-Hsin

2006-03-01

Positioning precision is crucial to today's increasingly high-speed, high-capacity, high data density, and miniaturized hard disk drives (HDDs). The demand for higher bandwidth servo systems that can quickly and precisely position the read/write head on a high track density becomes more pressing. Recently, the idea of applying dual-stage actuators to track servo systems has been studied. The push-pull piezoelectric actuated devices have been developed as micro actuators for fine and fast positioning, while the voice coil motor functions as a large but coarse seeking. However, the current dual-stage actuator design uses piezoelectric patches only without passive damping. In this paper, we propose a dual-stage servo system using enhanced active-passive hybrid piezoelectric actuators. The proposed actuators will improve the existing dual-stage actuators for higher precision and shock resistance, due to the incorporation of passive damping in the design. We aim to develop this hybrid servo system not only to increase speed of track seeking but also to improve precision of track following servos in HDDs. New piezoelectrically actuated suspensions with passive damping have been designed and fabricated. In order to evaluate positioning and track following performances for the dual-stage track servo systems, experimental efforts are carried out to implement the synthesized active-passive suspension structure with enhanced piezoelectric actuators using a composite nonlinear feedback controller.

Suppression of mechanical resonance in digital servo system considering oscillation frequency deviation

DEFF Research Database (Denmark)

Chen, Yangyang; Yang, Ming; Hu, Kun

2017-01-01

High-stiffness servo system is easy to cause mechanical resonance in elastic coupling servo system. Although on-line adaptive notch filter is effective in most cases, it will lead to a severer resonance when resonance frequency deviated from the natural torsional frequency. To explain...

Conceptual design of stepper motor replacing servo motor for control rod controller

International Nuclear Information System (INIS)

Mohd Dzul Aiman Aslan; Mohd Idris Taib; Izhar Abu Hussin; Mohd Khairulezwan Abdul Manan; Mohd Sabri Minhat

2010-01-01

In PUSPATI TRIGA Reactor, current control rod controller are using servo motor to control the movement. Control rod is a very important safety element and measure in every nuclear reactor. So, precision is very important in measurement of security in the nuclear reactor. In this case, there are a few disadvantages when using the servo motor is measurement of the motor is not precise. One solution to overcome this is by shifting servo motor with stepper motor. A stepper motor (or step motor) is a brush less, synchronous electric motor that can divide a full rotation into a large number of steps. (author)

Model-based nonlinear control of hydraulic servo systems: Challenges, developments and perspectives

Science.gov (United States)

Yao, Jianyong

2018-06-01

Hydraulic servo system plays a significant role in industries, and usually acts as a core point in control and power transmission. Although linear theory-based control methods have been well established, advanced controller design methods for hydraulic servo system to achieve high performance is still an unending pursuit along with the development of modern industry. Essential nonlinearity is a unique feature and makes model-based nonlinear control more attractive, due to benefit from prior knowledge of the servo valve controlled hydraulic system. In this paper, a discussion for challenges in model-based nonlinear control, latest developments and brief perspectives of hydraulic servo systems are presented: Modelling uncertainty in hydraulic system is a major challenge, which includes parametric uncertainty and time-varying disturbance; some specific requirements also arise ad hoc difficulties such as nonlinear friction during low velocity tracking, severe disturbance, periodic disturbance, etc.; to handle various challenges, nonlinear solutions including parameter adaptation, nonlinear robust control, state and disturbance observation, backstepping design and so on, are proposed and integrated, theoretical analysis and lots of applications reveal their powerful capability to solve pertinent problems; and at the end, some perspectives and associated research topics (measurement noise, constraints, inner valve dynamics, input nonlinearity, etc.) in nonlinear hydraulic servo control are briefly explored and discussed.

Performance verification and system parameter identification of spacecraft tape recorder control servo

Science.gov (United States)

Mukhopadhyay, A. K.

1979-01-01

Design adequacy of the lead-lag compensator of the frequency loop, accuracy checking of the analytical expression for the electrical motor transfer function, and performance evaluation of the speed control servo of the digital tape recorder used on-board the 1976 Viking Mars Orbiters and Voyager 1977 Jupiter-Saturn flyby spacecraft are analyzed. The transfer functions of the most important parts of a simplified frequency loop used for test simulation are described and ten simulation cases are reported. The first four of these cases illustrate the method of selecting the most suitable transfer function for the hysteresis synchronous motor, while the rest verify and determine the servo performance parameters and alternative servo compensation schemes. It is concluded that the linear methods provide a starting point for the final verification/refinement of servo design by nonlinear time response simulation and that the variation of the parameters of the static/dynamic Coulomb friction is as expected in a long-life space mission environment.

Compact, Lightweight Servo-Controllable Brakes

Science.gov (United States)

Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

2010-01-01

Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

Hydraulic servo control spool valve

Science.gov (United States)

Miller, Donald M.

1983-01-01

A servo operated spool valve having a fixed sleeve and axially movable spool. The sleeve is machined in two halves to form a long, narrow tapered orifice slot across which a transverse wall of the spool is positioned. The axial position of the spool wall along the slot regulates the open orifice area with extreme precision.

La fiesta, grito sagrado de la tierra y del pueblo: el sentido de la fiesta a partir de un pueblo de Madrid (The feast, Sacred scream of land and people: The meaning of feast in a village of Madrid - DOI: 10.5752/P.2175-5841.2011v9n20p83

Directory of Open Access Journals (Sweden)

Salustiano Alvaréz Gómez

2011-05-01

Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 A partir da experiência das festividades patronais duma pequena cidade de Madri, reflete-se sobre o sentido geral da festa, seu significado humano, sua necessidade coletiva e as interpretações dos grupos humanos em sua busca de objetivos. Este estudo parte da experiência pessoal na participação ativa das festas populares, ou seja, desde o saber-se membro de um grupo humano, para passar a uma análise científica, a partir dos paradigmas de R. Caillois, G. Dumezil e R. Otto. O objetivo pretende não somente viver a festa como analisar e estudar a festa. Desta festa concreta e particular, pode-se passar ao universal. De fato, a festa supõe um momento muito especial na historia dos grupos humanos, permitindo dimensionar sua vida desde um passado vivencial e um futuro de esperança. A festa permite quebrar a monotonia do cotidiano reorganizando a vida do grupo, possibilitando a alegria e o dinamismo da existência humana. Trata-se de uma necessidade humana, tão humana como o trabalho, onde o sagrado e o profano entram como formas integradoras da convivência. Convivência que necessita do riso, da alegria, da irreverência e da felicidade, além do trabalho, do compromisso e da ordem estabelecida.Palavras-chave: Antropologia da festa; sagrado e profano; sociedade; religião ResumenA partir de la experiencia de las festividades patronales de una pequeña ciudad de Madrid,  se reflexiona sobre el sentido general de la fiesta, su significado humano, su necesidad colectiva y las interpretaciones de los grupos humanos en su busca de objetivos sociales. Este estudio parte de la experiencia personal en la participación activa de las fiestas populares, o sea, desde saberse miembro de un grupo humano para pasar a un análisis científico, a partir dos paradigmas de R. Caillois, G. Dumezil y R. Otto. El objetivo pretende no solamente vivir la fiesta como analizar y estudiar la fiesta. De esta

Visual servoing in medical robotics: a survey. Part II: tomographic imaging modalities--techniques and applications.

Science.gov (United States)

Azizian, Mahdi; Najmaei, Nima; Khoshnam, Mahta; Patel, Rajni

2015-03-01

Intraoperative application of tomographic imaging techniques provides a means of visual servoing for objects beneath the surface of organs. The focus of this survey is on therapeutic and diagnostic medical applications where tomographic imaging is used in visual servoing. To this end, a comprehensive search of the electronic databases was completed for the period 2000-2013. Existing techniques and products are categorized and studied, based on the imaging modality and their medical applications. This part complements Part I of the survey, which covers visual servoing techniques using endoscopic imaging and direct vision. The main challenges in using visual servoing based on tomographic images have been identified. 'Supervised automation of medical robotics' is found to be a major trend in this field and ultrasound is the most commonly used tomographic modality for visual servoing. Copyright © 2014 John Wiley & Sons, Ltd.

Robust Hinfinity position control synthesis of an electro-hydraulic servo system.

Science.gov (United States)

Milić, Vladimir; Situm, Zeljko; Essert, Mario

2010-10-01

This paper focuses on the use of the techniques based on linear matrix inequalities for robust H(infinity) position control synthesis of an electro-hydraulic servo system. A nonlinear dynamic model of the hydraulic cylindrical actuator with a proportional valve has been developed. For the purpose of the feedback control an uncertain linearized mathematical model of the system has been derived. The structured (parametric) perturbations in the electro-hydraulic coefficients are taken into account. H(infinity) controller extended with an integral action is proposed. To estimate internal states of the electro-hydraulic servo system an observer is designed. Developed control algorithms have been tested experimentally in the laboratory model of an electro-hydraulic servo system. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

«Theater of Sorrows»: Rhetoric and Space in Francisco Romero's «Llanto Sagrado de la América Meridional»

Directory of Open Access Journals (Sweden)

Jorge Martín García

2016-11-01

Full Text Available This article aims to analyze the text entitled Llanto sagrado de la América Meridional written by the Augustinian friar Francisco Romero. The work presents a kind of spiritual mapping of american land. Therefore, the text divides the territory of the continent according to their proximity or remoteness from the true faith. Our main objective will be to examine the rhetorical mechanisms that lie behind this description of the Indian space.

O sagrado no romance hispano-americano do século XX (The sacred in the Hispanic-American novel of the 20th century - DOI: 10.5752/P.2175-5841.2013v11n29p279

Directory of Open Access Journals (Sweden)

Ana Lucia Trevisan

2013-03-01

Full Text Available O trabalho estuda as formas de representação do sagrado no romance hispano-americano do século XX e propõe uma reflexão sobre algumas formas de utilização das mitologias e tradições religiosas pela literatura. A presença das narrativas sagradas no texto literário do século XX surge marcada por uma renovada experiência estética, pois não se trata apenas de utilizar ou reutilizar uma temática exótica, mas, sim, perceber um potencial tradutor de verdades universais, imanentes aos textos religiosos ou mitologias ancestrais. O artigo propõe uma reflexão sobre as particularidades da produção literária europeia e hispano-americana, que utilizam os temas sagrados, a fim de perceber as consonâncias e dissonâncias estéticas e históricas. O fenômeno estético denominado “mitologismo”, estudado por E.M. Mielietinski, pode ser entendido como um modus operandi da estruturação do romance que conjuga literatura e relatos sagrados e, neste estudo, fundamenta a discussão sobre a heterogeneidade cultural dos povos hispânicos expressa em suas representações literárias. Palavras-chave: Romance . Mitologias. Religião. Hispano-América. Abstract This article studies the forms of representation of the sacred in the Hispanic-American novel of the 20th century and proposes a reflection on some ways of using the mythological and religious traditions by literature. The presence of sacred narratives in the literary texts of the 20th century is marked by a renewed aesthetic experience, once it does not only refer to using or re-using an exotic theme, but perceiving a potential translator of universal truths, immanent to religious texts or mythological ancestors. The present proposal offers a reflection on the peculiarities of European and Hispanic-American productions which make use of sacred themes, meaning to understand the aesthetic and historical consonances and dissonances. The aesthetic phenomenon named “mythologism”, studied

Los animales en los textos sagrados del Islam

Directory of Open Access Journals (Sweden)

Aurora Ribagorda Calasanz

1999-01-01

Full Text Available A través de los textos sagrados del Islam, fundamentalmente el Corán y la Sunna, este trabajo quiere subrayar la importancia del animal en el contexto religioso islámico. También se consideran las interpretaciones de la ley y el pensamiento jurídico de las diferentes escuelas, con especial atención al derecho islámico en al- Andalus. Finalmente se aborda el problema de la creación artística y la representación figurativa de seres vivos bajo el punto de vista de su fundamento jurídico y religioso. La conclusión remitirá a un hecho: la indisoclabllidad entre hombre y animal en el mundo islámico.Studying the sacred tests of Islam, bassicaily the Koran and the Sunna, this work Intends to show the important role of the animáis in the worid of islamic religión. Considerations are also made about this role in regard with the islamic laws and its different interpretations and judicial doctrines foilowing the differents schools. Special Interest is brought to the islamic law in al-Andalus. Finally this work deals with artistic creation and representation oflive beings submitted to the religious and judicial rules of Islam. A conclusión wiil be underlined: the very closed links between men and animáis in the islamic world.

Actuation and Control of a Micro Electrohydraulic Digital Servo Valve

Energy Technology Data Exchange (ETDEWEB)

Yu, Z Q; Hu, M J; Pei, X; Ruan, J [MOE Key Laboratory of Mechanical Manufacture and Automation Zhejiang University of Technology, 310014 (China)

2006-10-15

Structure of the micro digital servo valve is given. A micro stepper motor is used as electrical-to-mechanical interface of the valve. A special mechanical device is designed to convert the rotation of the stepper motor into the linear motion of the spool. This moving conversion device functions through an eccentric ball head rigidly connected to the axis of the stepper motor and plugged into a slot at the central spool land. While the stepper motor rotates, the eccentric ball head will actuate the spool to make a linear motion. Unlike conventional servo or proportional valves, in which the spool is forced to central position by a spring force, when the current supply is switched off, the digital valve has a program to control the spool to its central position each time the electrical power supply is switched on or off. The two end screws are used to adjust the position of the sleeve to sustain a mechanical central position coincided with electrical central position given by the stepper motor after initialization. The adjustment has to be carried once before the first time the servo valve is put into service. This paper presents theoretical analysis and experimental study of dynamic characteristics of the proposed micro digital servo valve. Experimental results demonstrated that the valve takes the advantage of high accuracy and fast response.

Actuation and Control of a Micro Electrohydraulic Digital Servo Valve

International Nuclear Information System (INIS)

Yu, Z Q; Hu, M J; Pei, X; Ruan, J

2006-01-01

Structure of the micro digital servo valve is given. A micro stepper motor is used as electrical-to-mechanical interface of the valve. A special mechanical device is designed to convert the rotation of the stepper motor into the linear motion of the spool. This moving conversion device functions through an eccentric ball head rigidly connected to the axis of the stepper motor and plugged into a slot at the central spool land. While the stepper motor rotates, the eccentric ball head will actuate the spool to make a linear motion. Unlike conventional servo or proportional valves, in which the spool is forced to central position by a spring force, when the current supply is switched off, the digital valve has a program to control the spool to its central position each time the electrical power supply is switched on or off. The two end screws are used to adjust the position of the sleeve to sustain a mechanical central position coincided with electrical central position given by the stepper motor after initialization. The adjustment has to be carried once before the first time the servo valve is put into service. This paper presents theoretical analysis and experimental study of dynamic characteristics of the proposed micro digital servo valve. Experimental results demonstrated that the valve takes the advantage of high accuracy and fast response

Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

International Nuclear Information System (INIS)

Kim, Hyo-gon; Han, Changsoo; Lee, Jong-won; Park, Sangdeok

2015-01-01

Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program

Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyo-gon; Han, Changsoo [Hanyang University, Seoul (Korea, Republic of); Lee, Jong-won [Korea University of Science and Technology, Seoul (Korea, Republic of); Park, Sangdeok [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)

2015-02-15

Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program.

Adaptive servo ventilation for central sleep apnoea in heart failure: SERVE-HF on-treatment analysis.

Science.gov (United States)

Woehrle, Holger; Cowie, Martin R; Eulenburg, Christine; Suling, Anna; Angermann, Christiane; d'Ortho, Marie-Pia; Erdmann, Erland; Levy, Patrick; Simonds, Anita K; Somers, Virend K; Zannad, Faiez; Teschler, Helmut; Wegscheider, Karl

2017-08-01

This on-treatment analysis was conducted to facilitate understanding of mechanisms underlying the increased risk of all-cause and cardiovascular mortality in heart failure patients with reduced ejection fraction and predominant central sleep apnoea randomised to adaptive servo ventilation versus the control group in the SERVE-HF trial.Time-dependent on-treatment analyses were conducted (unadjusted and adjusted for predictive covariates). A comprehensive, time-dependent model was developed to correct for asymmetric selection effects (to minimise bias).The comprehensive model showed increased cardiovascular death hazard ratios during adaptive servo ventilation usage periods, slightly lower than those in the SERVE-HF intention-to-treat analysis. Self-selection bias was evident. Patients randomised to adaptive servo ventilation who crossed over to the control group were at higher risk of cardiovascular death than controls, while control patients with crossover to adaptive servo ventilation showed a trend towards lower risk of cardiovascular death than patients randomised to adaptive servo ventilation. Cardiovascular risk did not increase as nightly adaptive servo ventilation usage increased.On-treatment analysis showed similar results to the SERVE-HF intention-to-treat analysis, with an increased risk of cardiovascular death in heart failure with reduced ejection fraction patients with predominant central sleep apnoea treated with adaptive servo ventilation. Bias is inevitable and needs to be taken into account in any kind of on-treatment analysis in positive airway pressure studies. Copyright ©ERS 2017.

Robust Control for High-Speed Visual Servoing Applications

DEFF Research Database (Denmark)

Ellekilde, Lars-Peter; Favrholdt, Peter; Paulin, Mads

2007-01-01

This paper presents a new control scheme for visual servoing applications. The approach employs quadratic optimization, and explicitly handles both joint position, velocity and acceleration limits. Contrary to existing techniques, our method does not rely on large safety margins and slow task...... execution to avoid joint limits, and is hence able to exploit the full potential of the robot. Furthermore, our control scheme guarantees a well-defined behavior of the robot even when it is in a singular configuration, and thus handles both internal and external singularities robustly. We demonstrate...... the correctness and efficiency of our approach in a number of visual servoing applications, and compare it to a range of previously proposed techniques....

New method to improve dynamic stiffness of electro-hydraulic servo systems

Science.gov (United States)

Bai, Yanhong; Quan, Long

2013-09-01

Most current researches working on improving stiffness focus on the application of control theories. But controller in closed-loop hydraulic control system takes effect only after the controlled position is deviated, so the control action is lagged. Thus dynamic performance against force disturbance and dynamic load stiffness can’t be improved evidently by advanced control algorithms. In this paper, the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil is analyzed. On this basis, the conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put forward. And a scheme using double servo valves to realize flow feedforward compensation is presented, in which another fast response servo valve is added to the regular electro hydraulic servo system and specially utilized to compensate the compressed oil volume caused by load impact in time. The two valves are arranged in parallel to control the cylinder jointly. Furthermore, the model of flow compensation is derived, by which the product of the amplitude and width of the valve’s pulse command signal can be calculated. And determination rules of the amplitude and width of pulse signal are concluded by analysis and simulations. Using the proposed scheme, simulations and experiments at different positions with different force changes are conducted. The simulation and experimental results show that the system dynamic performance against load force impact is largely improved with decreased maximal dynamic position deviation and shortened settling time. That is, system dynamic load stiffness is evidently raised. This paper proposes a new method which can effectively improve the dynamic stiffness of electro-hydraulic servo systems.

Los géneros imaginarios de lo sagrado. El budismo en el marketing publicitario

Directory of Open Access Journals (Sweden)

María Jesús Alonso Seoane

2010-07-01

Full Text Available Se analizan en este artículo las características simbólicas del género en el espacio de lo sagrado. Para ello se realiza un estudio de la imagen del budismo que los publicistas vienen haciendo en los últimos tiempos. Oriente ha identificado virtudes como la compasión y la sabiduría con géneros que nuestro marco cultural ha cambiado por completo. Se ejemplifican las conclusiones con un breve análisis publicitario, que emplea imágenes, tanto visuales como narrativas, del budismo en un intento de proporcionar un valor añadido a los productos publicitados. En el proceso de mostrar las virtudes “budistas” asociadas al producto, cambia el género de las mismas adaptándolas a nuestro modo occidental de entenderlas.

Researching on YH100 Numerical Control Servo Press Hydraulic Control System and Control Algorithm

Directory of Open Access Journals (Sweden)

Kai LI

2014-09-01

Full Text Available In order to study the numerical control (NC servo press hydraulic control system and its control algorithm. The numerical control servo press performance and control principle of hydraulic control system are analyzed. According to the flow equation of the hydraulic control valve, hydraulic cylinder flow continuity equation and the force balance equation of the hydraulic cylinder with load press, the mathematical model of hydraulic control system is established. And the servo press hydraulic system transfer function is deduced. Introducing the suitable immune particle swarm control algorithm for servo press hydraulic system, and the control system block diagram is established. Immune algorithm is used to optimize new control parameters of the system and adopt the new optimization results to optimize the system simulation. The simulation result shows that the hydraulic system’s transition time controlled by the immune particle swarm algorithm is shorter than traditional ones, and the control performance is obviously improved. Finally it can be concluded that immune particle swarm PID control have these characteristics such as quickness, stability and accuracy. Applying this principle into application, the obtained YH100 numerical control servo press hydraulic control system meets the requirement.

A deterministic - approach controller design for electrohydraulic position servo control system

International Nuclear Information System (INIS)

Johari Osman

2000-01-01

This paper is concerned with the design of a tracking controller for controlling electrohydraulic position servo system based on a deterministic approach. The system is treated as an uncertain system with bounded uncertainties where the bounds are assumed known. It will be shown that the electrohydraulic position servo systems with the proposed controller is practically stable and tracks the desired position in spite of the uncertainties and nonlinearities present in the system (author)

Visual Servoing of Mobile Microrobot with Centralized Camera

Directory of Open Access Journals (Sweden)

Kiswanto Gandjar

2018-01-01

Full Text Available In this paper, a mechanism of visual servoing for mobile microrobot with a centralized camera is developed. Especially for the development of swarm AI applications. In the fields of microrobots the size of robots is minimal and the amount of movement is also small. By replacing various sensors that is needed with a single centralized vision sensor we can eliminate a lot of components and the need for calibration on every robot. A study and design for a visual servoing mobile microrobot has been developed. This system can use multi object tracking and hough transform to identify the positions of the robots. And can control multiple robots at once with an accuracy of 5-6 pixel from the desired target.

Active Vibration Isolation Devices with Inertial Servo Actuators

Science.gov (United States)

Melik-Shakhnazarov, V. A.; Strelov, V. I.; Sofiyanchuk, D. V.; Tregubenko, A. A.

2018-03-01

The use of active vibration isolation devices (AVIDs) in aerospace engineering is subject to the following restrictions. First, the volume for installing additional devices is always limited in instrument racks and compartments. Secondly, in many cases, it is impossible to add supports for servo actuators for fundamental or design considerations. In the paper, it has been shown that this problem can be solved if the inertial servo actuators are used in AVIDs instead of reference actuators. A transfer function has been theoretically calculated for an AVID controlled by inertial actuators. It has been shown that the volume of a six-mode single-housing AVID with inertial actuators can be 2-2.5 times smaller than that of devices with support actuators.

Góngora and his Lady. Another Go at «De pura honestidad templo sagrado»

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Daniel Waissbein

2016-11-01

Full Text Available Giulia Poggi denies, in a recent study, that «De pura honestidad templo sagrado» describes the small sculpture of the Virgin of Villaviciosa in the Cathedral-Mosque of Córdoba, as suggested by me in 2010, and insists in the supposedly amatory character of the sonnet. In the following pages I demonstrate that neither of the two main arguments adduced by Poggi, a restrictive view of intertextuality, and an arbitrary summary of Pineda’s censorship comments, allow us to decide the point. Lastly, I indicate the comprehension mistakes of some lines of the sonnet by the Italian critic, which have led her astray; and I add some new factual information, related in part to Góngora’s converso condition, recently demonstrated, which strengthen the views that Poggi attempts to deny.

Magnetic particle clutch controls servo system

Science.gov (United States)

Fow, P. B.

1973-01-01

Magnetic clutches provide alternative means of driving low-power rate or positioning servo systems. They may be used over wide variety of input speed ranges and weigh comparatively little. Power drain is good with overall motor/clutch efficiency greater than 50 percent, and gain of clutch is close to linear, following hysteresis curve of core and rotor material.

A computer-based servo system for controlling isotonic contractions of muscle.

Science.gov (United States)

Smith, J P; Barsotti, R J

1993-11-01

We have developed a computer-based servo system for controlling isotonic releases in muscle. This system is a composite of commercially available devices: an IBM personal computer, an analog-to-digital (A/D) board, an Akers AE801 force transducer, and a Cambridge Technology motor. The servo loop controlling the force clamp is generated by computer via the A/D board, using a program written in QuickBASIC 4.5. Results are shown that illustrate the ability of the system to clamp the force generated by either skinned cardiac trabeculae or single rabbit psoas fibers down to the resolution of the force transducer within 4 ms. This rate is independent of the level of activation of the tissue and the size of the load imposed during the release. The key to the effectiveness of the system consists of two algorithms that are described in detail. The first is used to calculate the error signal to hold force to the desired level. The second algorithm is used to calculate the appropriate gain of the servo for a particular fiber and the size of the desired load to be imposed. The results show that the described computer-based method for controlling isotonic releases in muscle represents a good compromise between simplicity and performance and is an alternative to the custom-built digital/analog servo devices currently being used in studies of muscle mechanics.

An electro-hydraulic servo control system research for CFETR blanket RH

Energy Technology Data Exchange (ETDEWEB)

Chen, Changqi [Hefei University of Technology, Hefei 230009, Anhui (China); Tang, Hongjun, E-mail: taurustang@126.com [Hefei University of Technology, Hefei 230009, Anhui (China); Qi, Songsong [Hefei University of Technology, Hefei 230009, Anhui (China); Cheng, Yong; Feng, Hansheng; Peng, Xuebing; Song, Yuntao [Institute of Plasma Physics Chinese Academy of Sciences, Hefei 230031, Anhui (China)

2014-11-15

Highlights: • We discussed the conceptual design of CFETR blanket RH maintenance system. • The mathematical model of electro-hydraulic servo system was calculated. • A fuzzy adaptive PD controller was designed based on control theory and experience. • The co-simulation models of the system were established with AMESim/Simulink. • The fuzzy adaptive PD algorithm was designed as the core strategy of the system. - Abstract: Based on the technical design requirements of China Fusion Engineering Test Reactor (CFETR) blanket remote handling (RH) maintenance, this paper focus on the control method of achieving high synchronization accuracy of electro-hydraulic servo system. Based on fuzzy control theory and practical experience, a fuzzy adaptive proportional-derivative (PD) controller was designed. Then a more precise co-simulation model was established with AMESim/Simulink. Through the analysis of simulation results, a fuzzy adaptive PD control algorithm was designed as the core strategy of electro-hydraulic servo control system.

An electro-hydraulic servo control system research for CFETR blanket RH

International Nuclear Information System (INIS)

Chen, Changqi; Tang, Hongjun; Qi, Songsong; Cheng, Yong; Feng, Hansheng; Peng, Xuebing; Song, Yuntao

2014-01-01

Highlights: • We discussed the conceptual design of CFETR blanket RH maintenance system. • The mathematical model of electro-hydraulic servo system was calculated. • A fuzzy adaptive PD controller was designed based on control theory and experience. • The co-simulation models of the system were established with AMESim/Simulink. • The fuzzy adaptive PD algorithm was designed as the core strategy of the system. - Abstract: Based on the technical design requirements of China Fusion Engineering Test Reactor (CFETR) blanket remote handling (RH) maintenance, this paper focus on the control method of achieving high synchronization accuracy of electro-hydraulic servo system. Based on fuzzy control theory and practical experience, a fuzzy adaptive proportional-derivative (PD) controller was designed. Then a more precise co-simulation model was established with AMESim/Simulink. Through the analysis of simulation results, a fuzzy adaptive PD control algorithm was designed as the core strategy of electro-hydraulic servo control system

O retorno do religioso na contemporaneidade

Directory of Open Access Journals (Sweden)

Tiago Ribeiro Nunes

2008-12-01

Full Text Available O presente trabalho pretende analisar os novos modos de relação, entre a civilização e o sagrado, que emergem no contexto da contemporaneidade. Partindo principalmente das formulações freudianas e lacanianas sobre o tema, nosso objetivo primordial ao longo deste artigo é estabelecer parâmetros para compreender a ocorrência do "retorno ao sagrado no exato momento em que a humanidade enfrenta crises cada vez mais profundas e permanentes. Tal empreendimento nos permitirá verificar até que ponto o fortalecimento dos movimentos religiosos pode ser considerado como uma das conseqüências da queda dos referenciais que se realiza na contemporaneidade.

Preterm infant thermal care: differing thermal environments produced by air versus skin servo-control incubators.

Science.gov (United States)

Thomas, K A; Burr, R

1999-06-01

Incubator thermal environments produced by skin versus air servo-control were compared. Infant abdominal skin and incubator air temperatures were recorded from 18 infants in skin servo-control and 14 infants in air servo-control (26- to 29-week gestational age, 14 +/- 2 days postnatal age) for 24 hours. Differences in incubator and infant temperature, neutral thermal environment (NTE) maintenance, and infant and incubator circadian rhythm were examined using analysis of variance and scatterplots. Skin servo-control resulted in more variable air temperature, yet more stable infant temperature, and more time within the NTE. Circadian rhythm of both infant and incubator temperature differed by control mode and the relationship between incubator and infant temperature rhythms was a function of control mode. The differences between incubator control modes extend beyond temperature stability and maintenance of NTE. Circadian rhythm of incubator and infant temperatures is influenced by incubator control.

DC motors and servo-motors controlled by Raspberry Pi 2B

Directory of Open Access Journals (Sweden)

Šustek Michal

2017-01-01

Full Text Available The expanding capabilities of today’s microcontrollers and other devices lead to an increased utilization of these technologies in diverse fields. The automation and issue of remote control of moving objects belong to these fields. In this project, a microcontroller Raspberry Pi 2B was chosen for controlling DC motors and servo-motors. This paper provides basic insight into issue of controlling DC motors and servo-motors, connection between Raspberry and other components on breadboard and programming syntaxes for controlling motors in Python programming language.

Application of prediction of equilibrium to servo-controlled calorimetry measurements

International Nuclear Information System (INIS)

Mayer, R.L. II

1987-01-01

Research was performed to develop an endpoint prediction algorithm for use with calorimeters operating in the digital servo-controlled mode. The purpose of this work was to reduce calorimetry measurement times while maintaining the high degree of precision and low bias expected from calorimetry measurements. Data from routine operation of two calorimeters were used to test predictive models at each stage of development against time savings, precision, and robustness criteria. The results of the study indicated that calorimetry measurement times can be significantly reduced using this technique. The time savings is, however, dependent on parameters in the digital servo-control algorithm and on packaging characteristics of measured items

El centro sagrado del poder: París y los funerales de Estado republicanos

Directory of Open Access Journals (Sweden)

Avner Ben-Amos

2007-01-01

Full Text Available Una de las formas mediante las cuales la Tercera República francesa legitimó su gobierno fue mediante el uso simbólico del espacio urbano. Utilizando las teorías de Clifford Geertz de la dimensión cultural del poder y de Maurice Halbwachs de la memoria colectiva, este artículo analiza los itinerarios de los principales funerales parisinos de Estado organizados por el régimen para sus héroes políticos, militares y culturales. Las procesiones funerarias usualmente pasaban frente a los lugares principales del poder político del régimen, así como frente a los cuatro principales monumentos sagrados de la nación francesa: el Pantheón, los Invalides, el Arco del Triunfo y la catedral de Notre Dame. Así se conectaba simbólicamente el nuevo régimen republicano al pasado glorioso de Francia, y podía presentarse como continuador de esta tradición.

Fault Diagnosis of Hydraulic Servo Valve Based on Genetic Optimization RBF-BP Neural Network

Directory of Open Access Journals (Sweden)

Li-Ping FAN

2014-04-01

Full Text Available Electro-hydraulic servo valves are core components of the hydraulic servo system of rolling mills. It is necessary to adopt an effective fault diagnosis method to keep the hydraulic servo valve in a good work state. In this paper, RBF and BP neural network are integrated effectively to build a double hidden layers RBF-BP neural network for fault diagnosis. In the process of training the neural network, genetic algorithm (GA is used to initialize and optimize the connection weights and thresholds of the network. Several typical fault states are detected by the constructed GA-optimized fault diagnosis scheme. Simulation results shown that the proposed fault diagnosis scheme can give satisfactory effect.

Autonomous docking control of visual-servo type underwater vehicle system aiming at underwater automatic charging

International Nuclear Information System (INIS)

Yanou, Akira; Ohnishi, Shota; Ishiyama, Shintaro; Minami, Mamoru

2015-01-01

A visual-servo type remotely operated vehicle (ROV) system with binocular wide-angle lens was developed to survey submarine resources, decontaminate radiation from mud in dam lake and so on. This paper explores the experiments on regulator performance and underwater docking of the robot system utilizing Genetic Algorithm (GA) for real-time recognition of the robot's relative position and posture through 3D marker. The visual servoing performances have been verified as follows; (1) The stability performances of the proposed regulator system have been evaluated by exerting abrupt distrubane force while the ROV is controlled by visual servoing. (2) The proposed system can track time-variant desired target position in x-axis (front-back direction of the robot). (3) The underwater docking can be completed by switching visual servoing and docking modes based on the error threshold, and by giving time-varying desired target position and orientation to the controller as a desired pose. (author)

La condición del arte. Entre lo sagrado y lo profano Apuntes de sociología y antropología del arte

OpenAIRE

Julio Amador Bech

2006-01-01

En este artículo, el autor analiza el concepto de arte confrontando y cuestionando la oposición y diferencia entre la idea moderna y, con eso, profana, de arte y otra tradicional y antigua, inmersa en la sustancia de lo sagrado. A partir de las definiciones de "arte tradicional" propuestas por diversos autores, se establecen lineamientos teóricos generales para analizar de manera concreta las formas particulares en las que, en diversas culturas, el arte se sit...

Fusing Simulation Results From Multifidelity Aero-servo-elastic Simulators - Application To Extreme Loads On Wind Turbine

DEFF Research Database (Denmark)

Abdallah, Imad; Sudret, Bruno; Lataniotis, Christos

2015-01-01

Fusing predictions from multiple simulators in the early stages of the conceptual design of a wind turbine results in reduction in model uncertainty and risk mitigation. Aero-servo-elastic is a term that refers to the coupling of wind inflow, aerodynamics, structural dynamics and controls. Fusing...... the response data from multiple aero-servo-elastic simulators could provide better predictive ability than using any single simulator. The co-Kriging approach to fuse information from multifidelity aero-servo-elastic simulators is presented. We illustrate the co-Kriging approach to fuse the extreme flapwise...... bending moment at the blade root of a large wind turbine as a function of wind speed, turbulence and shear exponent in the presence of model uncertainty and non-stationary noise in the output. The extreme responses are obtained by two widely accepted numerical aero-servo-elastic simulators, FAST...

Analysis and Design of Double-sided Air core Linear Servo Motor with Trapezoidal Permanent Magnets

DEFF Research Database (Denmark)

Zhang, Yuqiu; Yang, Zilong; Yu, Minghu

2011-01-01

In order to reduce the thrust ripple of linear servo system, a double-sided air core permanent magnet linear servo motor with trapezoidal shape permanent magnets (TDAPMLSM) is proposed in this paper. An analytical model of the motor for predicting the magnetic field in the air-gap at no...

Research on Visual Servo Grasping of Household Objects for Nonholonomic Mobile Manipulator

Directory of Open Access Journals (Sweden)

Huangsheng Xie

2014-01-01

Full Text Available This paper focuses on the problem of visual servo grasping of household objects for nonholonomic mobile manipulator. Firstly, a new kind of artificial object mark based on QR (Quick Response Code is designed, which can be affixed to the surface of household objects. Secondly, after summarizing the vision-based autonomous mobile manipulation system as a generalized manipulator, the generalized manipulator’s kinematic model is established, the analytical inverse kinematic solutions of the generalized manipulator are acquired, and a novel active vision based camera calibration method is proposed to determine the hand-eye relationship. Finally, a visual servo switching control law is designed to control the service robot to finish object grasping operation. Experimental results show that QR Code-based artificial object mark can overcome the difficulties brought by household objects’ variety and operation complexity, and the proposed visual servo scheme makes it possible for service robot to grasp and deliver objects efficiently.

Visual servo control for a human-following robot

CSIR Research Space (South Africa)

Burke, Michael G

2011-03-01

Full Text Available This thesis presents work completed on the design of control and vision components for use in a monocular vision-based human-following robot. The use of vision in a controller feedback loop is referred to as vision-based or visual servo control...

Application of IFT and SPSA to servo system control.

Science.gov (United States)

Rădac, Mircea-Bogdan; Precup, Radu-Emil; Petriu, Emil M; Preitl, Stefan

2011-12-01

This paper treats the application of two data-based model-free gradient-based stochastic optimization techniques, i.e., iterative feedback tuning (IFT) and simultaneous perturbation stochastic approximation (SPSA), to servo system control. The representative case of controlled processes modeled by second-order systems with an integral component is discussed. New IFT and SPSA algorithms are suggested to tune the parameters of the state feedback controllers with an integrator in the linear-quadratic-Gaussian (LQG) problem formulation. An implementation case study concerning the LQG-based design of an angular position controller for a direct current servo system laboratory equipment is included to highlight the pros and cons of IFT and SPSA from an application's point of view. The comparison of IFT and SPSA algorithms is focused on an insight into their implementation.

Application of prediction of equilibrium to servo-controlled calorimetry measurements

International Nuclear Information System (INIS)

Mayer, R.L. II.

1987-01-01

Research was performed to develop an endpoint prediction algorithm for use with calorimeters operating in the digital servo-controlled mode. The purpose of this work was to reduce calorimetry measurement times while maintaining the high degree of precision and low bias expected from calorimetry measurements. Data from routine operation of two calorimeters were used to test predictive models at each stage of development against time savings, precision, and robustness criteria. The results of the study indicated that calorimetry measurement times can be significantly reduced using this technique. The time savings is, however, dependent on parameters in the digital servo-control algorithm and on packaging characteristics of measured items. 7 refs., 4 figs., 1 tab

A New Servo Control Drive for Electro Discharge Texturing System Industrial Applications Using Ultrasonic Technology

Directory of Open Access Journals (Sweden)

M. Shafik

2013-07-01

Full Text Available This paper presents a new ultrasonic servo control drive for electro discharge texturing system industrial applications. The new drive is aiming to overcome the current teething issues of the existing electro discharge texturing system, servo control drive level of precision, processing stability, dynamic response and surface profile of the machined products. The new ultrasonic servo control drive consists of three main apparatuses, an ultrasonic motor, electronic driver and control unit. The ultrasonic motor consists of three main parts, the stator, rotor and sliding element. The motor design process, basic configuration, principles of motion, finite element analysis and experimental examination of the main characteristics is discussed in this paper. The electronic driver of the motor consists of two main stages which are the booster and piezoelectric amplifier. The experimental test and validation of the developed servo control drive in electro discharge texturing platform is also discussed and presented in this paper. The initial results showed that the ultrasonic servo control drive is able to provide: a bidirectional of motion, a resolution of <50μm and a dynamic response of <10msec. The electron microscopic micro examination into the textured samples showed that: a clear improvement in machining stability, products surface profile, a notable reduction in the processing time, arcing and short-circuiting teething phenomena.

Visual-servoing optical microscopy

Science.gov (United States)

Callahan, Daniel E.; Parvin, Bahram

2009-06-09

The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time: quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

Forming of AHSS using Servo-Presses

Science.gov (United States)

Groseclose, Adam Richard

Stamping of Advanced High Strength Steel (AHSS) alloys poses several challenges due to the material's higher strength and low formability compared to conventional steels and other problems such as (a) inconsistency of incoming material properties, (b) ductile fracture during forming, (c) higher contact pressure and temperature rise during forming, (d) higher die wear leading to reduced tool life, (e) higher forming load/press capacity, and (f) large springback leading to dimensional inaccuracy in the formed part. [Palaniswamy et. al., 2007]. The use of AHSS has been increasing steadily in automotive stamping. New AHSS alloys (TRIP, TWIP) may replace some of the Hot Stamping applications. Stamping of AHSS alloys, especially higher strength materials, 780 MPa and higher, present new challenges in obtaining good part definition (corner and fillet radii), formability (fracture and resulting scrap) and in reducing springback. Servo-drive presses, having the capability to have infinitely variable and adjustable ram speed and dwell at BDC, offer a potential improvement in quality, part definition, and springback reduction especially when the infinitely adjustable slide motion is used in combination with a CNC hydraulic cushion. Thus, it is desirable to establish a scientific/engineering basis for improving the stamping conditions in forming AHSS using a servo-drive press.

A RELEVÂNCIA DOS MITOS RELIGIOSOS NA TRAJETÓRIA DE PI

Directory of Open Access Journals (Sweden)

Míriam Zafalon (UEM

2015-03-01

Full Text Available A mitologia tem construído, no decorrer dos tempos, um cabedal de informações sobre a sabedoria na antiguidade, explicitando como o pensamento tradicional, apoiado no mito, pôde estabelecer parâmetros para nortear os comportamentos humanos. O caráter sagrado do mito tem sido renovado e vivificado por meio dos discursos religiosos, artísticos e cotidianos, revisitando as histórias que transmitem o legado das civilizações para a existência de todas as épocas. Os mitos sempre estiveram relacionados à religião, sendo revelados por intermédio dos ritos os quais naturalizavam o habitus vigente. A proximidade entre o mundo contemporâneo e os mitos criados há milhares de anos se constrói sobre as lições de sabedoria, sempre atuais, que provêm do espaço mitológico. Tal aproximação presentifica-se no âmbito das artes em geral, demonstrando a influência que a tradição exerce em todas as áreas da compreensão humana. O trabalho aqui exposto faz uma leitura do livro As aventuras de Pi, de Yann Martel, com o intuito de demonstrar como a obra recupera várias alegorias religiosas, encaminhando o herói ao autoconhecimento. Referenciando diferentes práticas religiosas, o jovem Pi delineia um caminho oposto ao ceticismo que domina o pensamento dos homens da atualidade, expressando a união do homem com o seu universo, permeada pela irrupção do sagrado.PALAVRAS-CHAVE: As aventuras de Pi. Mito. Alegorias religiosas. Abstract The mythology has created, in the course of time, a wealth of information about the wisdom in ancient times, explaining how the traditional thinking, supported in myth, could establish parameters to guide human behavior. The sacred character of myth has been modernized and vitalized by means of language, by revisiting the stories that transmit the civilizations’ patrimony to the existence of all times. The myths have always been related to religion and revealed through the rites, which naturalized the

Research on intelligent algorithm of electro - hydraulic servo control system

Science.gov (United States)

Wang, Yannian; Zhao, Yuhui; Liu, Chengtao

2017-09-01

In order to adapt the nonlinear characteristics of the electro-hydraulic servo control system and the influence of complex interference in the industrial field, using a fuzzy PID switching learning algorithm is proposed and a fuzzy PID switching learning controller is designed and applied in the electro-hydraulic servo controller. The designed controller not only combines the advantages of the fuzzy control and PID control, but also introduces the learning algorithm into the switching function, which makes the learning of the three parameters in the switching function can avoid the instability of the system during the switching between the fuzzy control and PID control algorithms. It also makes the switch between these two control algorithm more smoother than that of the conventional fuzzy PID.

MA-23-6000: underwater bilateral servo master slave manipulator

International Nuclear Information System (INIS)

Vertut, Jean

The different types of manipulators, recent data on their dexterity and the underwater work possible with servo master slave manipulators are reviewed. The general specifications of the manipulator MA 23-6000 designed for the machine ERIC II are given [fr

Utilização do Sig na Delimitação das Áreas de Preservação Permanente (APP’s) na Bacia do Rio Sagrado (Morretes/PR) / Use of Gis in the Delimitation of Mandatory Preservation Areas in the Hydrographic Basin of Sagrado River (Morretes/PR)

OpenAIRE

Alexei Nowatzki; Leonardo José Cordeiro Santos; Eduardo Vedor de Paula

2010-01-01

O presente trabalho se enquadra no Programa CAD (Contaminantes, Assoreamento e Dragagem) no Estuário de Paranaguá/PR, tendo por objetivo a utilização do SIG (Sistema de Informações Geográficas) para a delimitação das Áreas de Preservação Permanente (APP's), na bacia hidrográfica do Rio Sagrado (Morretes/PR). Como etapa preliminar efetuou-se o estudo da legislação brasileira vigente (Código Florestal e resoluções CONAMA) no que se refere à delimitação das APP's. Em seguida, por meio do softwar...

Cloud-based Networked Visual Servo Control

OpenAIRE

Wu, Haiyan; Lu, Lei; Chen, Chih-Chung; Hirche, Sandra; Kühnlenz, Kolja

2013-01-01

The performance of vision-based control systems, in particular of highly dynamic vision-based motion control systems, is often limited by the low sampling rate of the visual feedback caused by the long image processing time. In order to overcome this problem, the networked visual servo control, which integrates networked computational resources for cloud image processing, is considered in this article. The main contributions of this article are i) a real-time transport protocol for transmitti...

Encuentro comunitario de trueques: Un atractivo para el llamado turismo comunitario. Una experiencia solidaria en la micro-cuenca de Río Sagrado, Morretes, Paraná

Directory of Open Access Journals (Sweden)

Talita Cristina Zechner

2008-01-01

Full Text Available Para tener una sociedad en que predomine la igualdad entre todos sus miembros es necesario que la economía sea solidaria en vez de competitiva, dice Singer (2002, p.9. En este sentido, incontables comunidades vienen recogiendo alternativas para superar momentos de crisis u oportunizar una instancia donde sus miembros puedan compartir bienes, servicios y o/conocimientos. En la micro-cuenca de Río Sagrado, localidad rural de Morretes/Paraná, la creación del Encuentro Comunitario de Trueques Solidarios del Río Sagrado viene ha ejecutado ejecutando un espacio donde miembros de la comunidad, propietarios de chacras de fines de semana y visitantes se encuentran para intercambiar conocimientos, miradas y cuentos. Con el objetivo de verificar de qué manera este encuentro viene ocurriendo, su importancia para la comunidad local y su potencialidad de transformarse en un atractivo turístico, fue realizada esta investigación cualitativa. Hay un número creciente de participantes, miembros de la comunidad autóctona, propietarios de residencias secundarias (dueños de chacras y visitantes: han instaurado el intercambio de bienes, servicios y conocimientos, creándose un ambiente de convivencia entre modos de vida diferentes, lo que acabó por transformarse en uno de los principales atractivos de lo que hoy en día es llamado turismo comunitario.

Analysis of the jet pipe electro-hydraulic servo valve with finite element methods

Directory of Open Access Journals (Sweden)

Kaiyu Zhao

2018-01-01

Full Text Available The dynamic characteristics analysis about the jet pipe electro-hydraulic servo valve based on experience and mathematical derivation was difficult and not so precise. So we have analysed the armature feedback components, torque motor and jet pipe receiver in electrohydraulic servo valve by sophisticated finite element analysis tools respectively and have got physical meaning data on these parts. Then the data were fitted by Matlab and the mathematical relationships among them were calculated. We have done the dynamic multi-physical fields’ Simulink co-simulation using above mathematical relationship, and have got the input-output relationship of the overall valve, the frequency response and step response. This work can show the actual working condition accurately. At the same time, we have considered the materials and the impact of the critical design dimensions in the finite element analysis process. It provides some new ideas to the overall design of jet pipe electro-hydraulic servo valve.

Evaluating transient performance of servo mechanisms by analysing stator current of PMSM

Science.gov (United States)

Zhang, Qing; Tan, Luyao; Xu, Guanghua

2018-02-01

Smooth running and rapid response are the desired performance goals for the transient motions of servo mechanisms. Because of the uncertain and unobservable transient behaviour of servo mechanisms, it is difficult to evaluate their transient performance. Under the effects of electromechanical coupling, the stator current signals of a permanent-magnet synchronous motor (PMSM) potentially contain the performance information regarding servo mechanisms in use. In this paper, a novel method based on analysing the stator current of the PMSM is proposed for quantifying the transient performance. First, a vector control model is constructed to simulate the stator current behaviour in the transient processes of consecutive speed changes, consecutive load changes, and intermittent start-stops. It is discovered that the amplitude and frequency of the stator current are modulated by the transient load torque and motor speed, respectively. The stator currents under different performance conditions are also simulated and compared. Then, the stator current is processed using a local means decomposition (LMD) algorithm to extract the instantaneous amplitude and instantaneous frequency. The sample entropy of the instantaneous amplitude, which reflects the complexity of the load torque variation, is calculated as a performance indicator of smooth running. The peak-to-peak value of the instantaneous frequency, which defines the range of the motor speed variation, is set as a performance indicator of rapid response. The proposed method is applied to both simulated data in an intermittent start-stops process and experimental data measured for a batch of servo turrets for turning lathes. The results show that the performance evaluations agree with the actual performance.

Active control of residual tool marks for freeform optics functionalization by novel biaxial servo assisted fly cutting.

Science.gov (United States)

Zhu, Zhiwei; To, Suet; Zhang, Shaojian

2015-09-01

The inherent residual tool marks (RTM) with particular patterns highly affect optical functions of the generated freeform optics in fast tool servo or slow tool servo (FTS/STS) diamond turning. In the present study, a novel biaxial servo assisted fly cutting (BSFC) method is developed for flexible control of the RTM to be a functional micro/nanotexture in freeform optics generation, which is generally hard to achieve in FTS/STS diamond turning. In the BSFC system, biaxial servo motions along the z-axis and side-feeding directions are mainly adopted for primary surface generation and RTM control, respectively. Active control of the RTM from the two aspects, namely, undesired effect elimination or effective functionalization, are experimentally demonstrated by fabricating a typical F-theta freeform surface with scattering homogenization and two functional microstructures with imposition of secondary phase gratings integrating both reflective and diffractive functions.

Robustness-tracking control based on sliding mode and H∞ theory for linear servo system

Institute of Scientific and Technical Information of China (English)

TIAN Yan-feng; GUO Qing-ding

2005-01-01

A robustness-tracking control scheme based on combining H∞ robust control and sliding mode control is proposed for a direct drive AC permanent-magnet linear motor servo system to solve the conflict between tracking and robustness of the linear servo system. The sliding mode tracking controller is designed to ensure the system has a fast tracking characteristic to the command, and the H∞ robustness controller suppresses the disturbances well within the close loop( including the load and the end effect force of linear motor etc. ) and effectively minimizes the chattering of sliding mode control which influences the steady state performance of the system. Simulation results show that this control scheme enhances the track-command-ability and the robustness of the linear servo system, and in addition, it has a strong robustness to parameter variations and resistance disturbances.

Servo-control of water and sodium homeostasis during renal clearance measurements in conscious rats

DEFF Research Database (Denmark)

Thomsen, Klaus; Shirley, David G

2007-01-01

Servo-controlled fluid and sodium replacement during clearance studies is used in order to prevent loss of body fluid and sodium following diuretic/natriuretic procedures. However, even under control conditions, the use of this technique is sometimes associated with increases in proximal tubular...... fluid output (assessed by lithium clearance) and excretion rates. The present study examined the reason for these increases. The first series of experiments showed that one cause is volume overloading. This can occur if the servo system is activated from the start, i.e., during the establishment...... not seen when blood samples are replaced with the animal's own red blood cells resuspended in isotonic saline. When these pitfalls are avoided, servo-controlled sodium and fluid replacement is a reliable technique that makes it possible to study the effects of natriuretic and/or diuretic stimuli without...

Development of friction welding method by electric servo motors; Dendo servo shiki masatsu assetsuho no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Suzuki, H; Onuma, M; Hasegawa, T; Sakamoto, T [Toyota Motor Corp., Aichi (Japan)

1997-10-01

The standard friction welding has two methods; the brake method and the inertia method. We have developed a new friction welding method with the electric servo motor system. The forming of plastic fluidity layers of interface is evaluated quantitatively with the feedback control characteristics. The new method has enabled to reduce the heat effect and the burr of friction welding. In the method, we could reduce the getting heat energy, from one-third to half less than the previous methods. 6 refs., 16 figs.

Fuzzy control of small servo motors

Science.gov (United States)

Maor, Ron; Jani, Yashvant

1993-01-01

To explore the benefits of fuzzy logic and understand the differences between the classical control methods and fuzzy control methods, the Togai InfraLogic applications engineering staff developed and implemented a motor control system for small servo motors. The motor assembly for testing the fuzzy and conventional controllers consist of servo motor RA13M and an encoder with a range of 4096 counts. An interface card was designed and fabricated to interface the motor assembly and encoder to an IBM PC. The fuzzy logic based motor controller was developed using the TILShell and Fuzzy C Development System on an IBM PC. A Proportional-Derivative (PD) type conventional controller was also developed and implemented in the IBM PC to compare the performance with the fuzzy controller. Test cases were defined to include step inputs of 90 and 180 degrees rotation, sine and square wave profiles in 5 to 20 hertz frequency range, as well as ramp inputs. In this paper we describe our approach to develop a fuzzy as well as PH controller, provide details of hardware set-up and test cases, and discuss the performance results. In comparison, the fuzzy logic based controller handles the non-linearities of the motor assembly very well and provides excellent control over a broad range of parameters. Fuzzy technology, as indicated by our results, possesses inherent adaptive features.

Robust and Stable Disturbance Observer of Servo System for Low-Speed Operation

DEFF Research Database (Denmark)

Lee, Kyo Beum; Blaabjerg, Frede

2007-01-01

A new scheme to estimate the moment of inertia in the servo motor drive system in very low speed is proposed in this paper. The speed estimation scheme in most servo drive systems for low-speed operation is sensitive to the variation of machine parameter, especially the moment of inertia....... To estimate the motor inertia value, the observer using the Radial Basis Function Network (RBFN) is applied. A control law for stabilizing the system and adaptive laws for updating both of the weights in the RBFN and a bounding constant are established so that the whole closed-loop system is stable...

Performance Improvement of Servo Machine Low Speed Operation Using RBFN Disturbance Observer

DEFF Research Database (Denmark)

Lee, Kyo-Beum; Blaabjerg, Frede

2004-01-01

A new scheme to estimate the moment of inertia in the servo motor drive system in very low speed is proposed in this paper. The typical speed estimation scheme in most servo system for low speed operation is sensitive to the variation of machine parameters, especially the moment of inertia....... To estimate the motor inertia value, the observer using the Radial Basis Function Networks (RBFN) is applied. The effectiveness of the proposed inertia estimation method is verified by experiments. It is concluded that the speed control performance in the low speed region is improved with the proposed...

The research on algorithms for optoelectronic tracking servo control systems

Science.gov (United States)

Zhu, Qi-Hai; Zhao, Chang-Ming; Zhu, Zheng; Li, Kun

2016-10-01

The photoelectric servo control system based on PC controllers is mainly used to control the speed and position of the load. This paper analyzed the mathematical modeling and the system identification of the servo system. In the aspect of the control algorithm, the IP regulator, the fuzzy PID, the Active Disturbance Rejection Control (ADRC) and the adaptive algorithms were compared and analyzed. The PI-P control algorithm was proposed in this paper, which not only has the advantages of the PI regulator that can be quickly saturated, but also overcomes the shortcomings of the IP regulator. The control system has a good starting performance and the anti-load ability in a wide range. Experimental results show that the system has good performance under the guarantee of the PI-P control algorithm.

Modeling, simulation, and identification of the servo pumps

Energy Technology Data Exchange (ETDEWEB)

Negoita, C G; Vasiliu, D; Vasiliu, Ne; Calinoiu, C, E-mail: claudia.negoita@gmail.co [Faculty of Power Engineering, University POLITEHNICA of Bucharest 313, Splaiul Independentei, Bucharest, 060042 (Romania)

2010-08-15

This paper contains the results of a systematic research on the steady-state behavior, and the transients occurring in a basic hydrostatic system containing a servo pump. The optimum structure of such a device working in given condition is found step by step, the synthesis stages are alternating with the analysis ones, in order to establish some general synthesis criteria, as well as for creating some images of the design parameters influence on the real system dynamic behavior. The dynamic computation of the servo pumps is based on the experimental researches carried out by the authors on the control force of the variable displacement axial piston pumps. The analysis takes into account the pressure feedback, the rigid or spring mechanical feedback or the electrical position feedback. The theoretical models are developed by AMESim (Advanced Modeling and Simulation Environment for Systems Engineering). The experimental tests were performed by the aid of LabVIEW software from National Instruments Corporation in the frame of a national certified laboratory set up by the aid of Parker Hannifin Corporation.

Control-structure interaction in precision pointing servo loops

Science.gov (United States)

Spanos, John T.

1989-01-01

The control-structure interaction problem is addressed via stability analysis of a generic linear servo loop model. With the plant described by the rigid body mode and a single elastic mode, structural flexibility is categorized into one of three types: (1) appendage, (2) in-the-loop minimum phase, and (3) in-the-loop nonminimum phase. Closing the loop with proportional-derivative (PD) control action and introducing sensor roll-off dynamics in the feedback path, stability conditions are obtained. Trade studies are conducted with modal frequency, modal participation, modal damping, loop bandwidth, and sensor bandwidth treated as free parameters. Results indicate that appendage modes are most likely to produce instability if they are near the sensor rolloff, whereas in-the-loop modes are most dangerous near the loop bandwidth. The main goal of this paper is to provide a fundamental understanding of the control-structure interaction problem so that it may benefit the design of complex spacecraft and pointing system servo loops. In this framework, the JPL Pathfinder gimbal pointer is considered as an example.

Project calculation of the steering mechanism hydraulic servo control in motor vehicles

Directory of Open Access Journals (Sweden)

Zoran Đukan Majkić

2013-10-01

Full Text Available Hydraulic servo controls are designed to facilitate rotation in place without providing increased ppower to steering wheels. In the initial design phase, the dimensions required for control systems are usually obtained through the calculation of their load when wheels rotate in place, where the torque is calculated empirically. The starting point in the project calculation is thus to determine the hydraulic power steering torque torsional resistance which is then used to determine the maximum value of force i.e. the torque on the stering wheel. The calculation of the control system servo control consists of determining the basic parameters, the required pump capacity, the main dimensions of the hub and the  pipeline and the conditions for the stability of the system control mechanism. Introduction The aim of the calculation of the steering control system is to determine the basic parameters of its components which ensure the fulfilment of requirements of the control system. Calculations are performed in several stages with a simultaneous  detailed constructive analysis of the control system leading to the best variant. At each stage, design and control calculations of the hydraulic servo of the steering mechanism are performed. The design allows the computation to complete the selection of basic dimensions of the amplifer elements, starting from the approved scheme and the basic building loads of approximate values. Calculations control is carried out to clarify the structural solution and to obtain the output characteristics of the control amplifier which are applied in the  estimation of  potential properties of the structure. Project calculation Baseline data must be sufficiently reliable, ie. must correspond to the construction characteristics of the vehicle design and the control system as well as to service conditions..A proper deterimination of the torque calculation of torsional resistance in wheels is of utmost importance. Moment of

Visual servoing in medical robotics: a survey. Part I: endoscopic and direct vision imaging - techniques and applications.

Science.gov (United States)

Azizian, Mahdi; Khoshnam, Mahta; Najmaei, Nima; Patel, Rajni V

2014-09-01

Intra-operative imaging is widely used to provide visual feedback to a clinician when he/she performs a procedure. In visual servoing, surgical instruments and parts of tissue/body are tracked by processing the acquired images. This information is then used within a control loop to manoeuvre a robotic manipulator during a procedure. A comprehensive search of electronic databases was completed for the period 2000-2013 to provide a survey of the visual servoing applications in medical robotics. The focus is on medical applications where image-based tracking is used for closed-loop control of a robotic system. Detailed classification and comparative study of various contributions in visual servoing using endoscopic or direct visual images are presented and summarized in tables and diagrams. The main challenges in using visual servoing for medical robotic applications are identified and potential future directions are suggested. 'Supervised automation of medical robotics' is found to be a major trend in this field. Copyright © 2013 John Wiley & Sons, Ltd.

Adaptive fuzzy PID control of hydraulic servo control system for large axial flow compressor

Science.gov (United States)

Wang, Yannian; Wu, Peizhi; Liu, Chengtao

2017-09-01

To improve the stability of the large axial compressor, an efficient and special intelligent hydraulic servo control system is designed and implemented. The adaptive fuzzy PID control algorithm is used to control the position of the hydraulic servo cylinder steadily, which overcomes the drawback that the PID parameters should be adjusted based on the different applications. The simulation and the test results show that the system has a better dynamic property and a stable state performance.

Inherent limitations of fixed time servo-controlled radiometric calorimetry

International Nuclear Information System (INIS)

Wetzel, J.R.; Duff, M.F.; Lemming, J.F.

1987-01-01

There has been some interest in low precision, short run time calorimetry measurements. This type of calorimetry measurement has been proposed for use when high precision measurements are not required, for example, to screen scrap containers to determine if there is enough material to be measured more accurately of for confirmatory measurements that only require low precision results. The equipment needed to make these measurements is a servo-controlled calorimeter with a sample preequilibration bath. The preequilibration bath temperature is set to the internal temperature of the calorimeter running at a fixed servo-controlled wattage level. The sample power value is determined at a fixed time form the sample loading into the calorimeter. There are some limitations and areas of uncertainties in the use of data obtained by this method. Data collected under controlled conditions demonstrate the limitations. Sample packaging, preequilibration time, and item wattage were chosen as the variables most likely to be encountered in a plant environment

Inherent limitations of fixed-time, servo-controlled radiometric calorimetry

International Nuclear Information System (INIS)

Wetzel, J.R.; Lemming, J.F.; Duff, M.F.

1987-01-01

Interest has been shown in using fixed-time, servo-controlled calorimetry to shorten the measurement times for certain samples that require low precision values (3 to 5%). This type of calorimeter measurement could be particularly useful for screening scrap samples to determine whether there is a need for a more accurate measurement or for certain confirmatory measurements for which low precision numbers are sufficient. The equipment required for this type of measurement is a servo-controlled calorimeter and a preconditioning unit. Samples to be measured are placed in the preconditioning unit, which is maintained at the internal temperature of the calorimeter. The power value for the sample is determined at a fixed time after loading into the calorimeter, for example, 30 min. When a calorimeter is operated using a fixed cutoff time, there are additional sources of uncertainty that need to be considered. The major factors affecting the uncertainty of the calorimetry power values are discussed. 2 refs., 4 figs

Servo-Drive Amplifier for Micro-Satellite Superconductor-Levitated Flywheels, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — A new servo-drive technology is available to support energy storage and navigation for micro-satellites. Exploiting the ?pinning? effect of high-temperature...

Adaptive Neural Network Control for Nonlinear Hydraulic Servo-System with Time-Varying State Constraints

Directory of Open Access Journals (Sweden)

Shu-Min Lu

2017-01-01

Full Text Available An adaptive neural network control problem is addressed for a class of nonlinear hydraulic servo-systems with time-varying state constraints. In view of the low precision problem of the traditional hydraulic servo-system which is caused by the tracking errors surpassing appropriate bound, the previous works have shown that the constraint for the system is a good way to solve the low precision problem. Meanwhile, compared with constant constraints, the time-varying state constraints are more general in the actual systems. Therefore, when the states of the system are forced to obey bounded time-varying constraint conditions, the high precision tracking performance of the system can be easily realized. In order to achieve this goal, the time-varying barrier Lyapunov function (TVBLF is used to prevent the states from violating time-varying constraints. By the backstepping design, the adaptive controller will be obtained. A radial basis function neural network (RBFNN is used to estimate the uncertainties. Based on analyzing the stability of the hydraulic servo-system, we show that the error signals are bounded in the compacts sets; the time-varying state constrains are never violated and all singles of the hydraulic servo-system are bounded. The simulation and experimental results show that the tracking accuracy of system is improved and the controller has fast tracking ability and strong robustness.

Data-Driven Based Asynchronous Motor Control for Printing Servo Systems

Science.gov (United States)

Bian, Min; Guo, Qingyun

Modern digital printing equipment aims to the environmental-friendly industry with high dynamic performances and control precision and low vibration and abrasion. High performance motion control system of printing servo systems was required. Control system of asynchronous motor based on data acquisition was proposed. Iterative learning control (ILC) algorithm was studied. PID control was widely used in the motion control. However, it was sensitive to the disturbances and model parameters variation. The ILC applied the history error data and present control signals to approximate the control signal directly in order to fully track the expect trajectory without the system models and structures. The motor control algorithm based on the ILC and PID was constructed and simulation results were given. The results show that data-driven control method is effective dealing with bounded disturbances for the motion control of printing servo systems.

Pressure control of hydraulic servo system using proportional control valve

International Nuclear Information System (INIS)

Yang, Kyong Uk; Oh, In Ho; Lee, Ill Yeong

1999-01-01

The purpose of this study is to develop a control scheme for the hydraulic servo system which can rapidly control the pressure in a hydraulic cylinder with very short stroke. Compared with the negligible stroke of the cylinder in the system, the flow gain of the proportional pressure control valve constituting the hydraulic servo system is relatively large and the time delay on the response of the valve is quite long. Therefore, the pressure control system, in this study tends to get unstable during operations. Considering the above mentioned characteristics of the system, a two-degree-of-freedom control scheme, composed of the I-PDD 2 ... feedback compensator and the feedforward controller, is proposed. The reference model scheme is used in deciding the parameters of the controllers. The validity of the proposed control scheme is confirmed through the experiments

Servo-hydraulic actuator in controllable canonical form: Identification and experimental validation

Science.gov (United States)

Maghareh, Amin; Silva, Christian E.; Dyke, Shirley J.

2018-02-01

Hydraulic actuators have been widely used to experimentally examine structural behavior at multiple scales. Real-time hybrid simulation (RTHS) is one innovative testing method that largely relies on such servo-hydraulic actuators. In RTHS, interface conditions must be enforced in real time, and controllers are often used to achieve tracking of the desired displacements. Thus, neglecting the dynamics of hydraulic transfer system may result either in system instability or sub-optimal performance. Herein, we propose a nonlinear dynamical model for a servo-hydraulic actuator (a.k.a. hydraulic transfer system) coupled with a nonlinear physical specimen. The nonlinear dynamical model is transformed into controllable canonical form for further tracking control design purposes. Through a number of experiments, the controllable canonical model is validated.

The design of a servo system for a Moessbauer spectrometer

International Nuclear Information System (INIS)

Cranshaw, T.E.

1981-06-01

This report describes the design of a transducer system and servo drive amplifier suitable for Moessbauer spectrometers. Particular attention is paid to low and zero frequency drift. Measurements of the loop gain of a practical system are presented. (author)

Disturbance observer that uses radial basis function networks for the low speed control of a servo motor

DEFF Research Database (Denmark)

Lee, Kyo-Beum; Bae, C.H.; Blaabjerg, Frede

2005-01-01

A scheme to estimate the moment of inertia in a servo motor drive system at very low speed is proposed. The typical speed estimation scheme used in most servo systems operated at low speed is highly sensitive to variations in the moment of inertia. An observer that uses a radial basis function...

Improving dynamic performances of PWM-driven servo-pneumatic systems via a novel pneumatic circuit.

Science.gov (United States)

Taghizadeh, Mostafa; Ghaffari, Ali; Najafi, Farid

2009-10-01

In this paper, the effect of pneumatic circuit design on the input-output behavior of PWM-driven servo-pneumatic systems is investigated and their control performances are improved using linear controllers instead of complex and costly nonlinear ones. Generally, servo-pneumatic systems are well known for their nonlinear behavior. However, PWM-driven servo-pneumatic systems have the advantage of flexibility in the design of pneumatic circuits which affects the input-output linearity of the whole system. A simple pneumatic circuit with only one fast switching valve is designed which leads to a quasi-linear input-output relation. The quasi-linear behavior of the proposed circuit is verified both experimentally and by simulations. Closed loop position control experiments are then carried out using linear P- and PD-controllers. Since the output position is noisy and cannot be directly differentiated, a Kalman filter is designed to estimate the velocity of the cylinder. Highly improved tracking performances are obtained using these linear controllers, compared to previous works with nonlinear controllers.

Image-Based Visual Servoing for Robotic Systems: A Nonlinear Lyapunov-Based Control Approach

International Nuclear Information System (INIS)

Dixon, Warren

2003-01-01

The objective of this project is to enable current and future EM robots with an increased ability to perceive and interact with unstructured and unknown environments through the use of camera-based visual servo controllers. The scientific goals of this research are to develop a new visual servo control methodology that: (1) adapts for the unknown camera calibration parameters (e.g., focal length, scaling factors, camera position, and orientation) and the physical parameters of the robotic system (e.g., mass, inertia, friction), (2) compensates for unknown depth information (extract 3D information from the 2D image), and (3) enables multi-uncalibrated cameras to be used as a means to provide a larger field-of-view. Nonlinear Lyapunov-based techniques in conjunction with results from projective geometry are being used to overcome the complex control issues and alleviate many of the restrictive assumptions that impact current visual servo controlled robotic systems. The potential relevance of this control methodology will be a plug-and-play visual servoing control module that can be utilized in conjunction with current technology such as feature extraction and recognition, to enable current EM robotic systems with the capabilities of increased accuracy, autonomy, and robustness, with a larger field of view (and hence a larger workspace). These capabilities will enable EM robots to significantly accelerate D and D operations by providing for improved robot autonomy and increased worker productivity, while also reducing the associated costs, removing the human operator from the hazardous environments, and reducing the burden and skill of the human operators

Image-Based Visual Servoing for Robotic Systems: A Nonlinear Lyapunov-Based Control Approach

International Nuclear Information System (INIS)

Dixon, Warren

2002-01-01

The objective of this project is to enable current and future EM robots with an increased ability to perceive and interact with unstructured and unknown environments through the use of camera-based visual servo controlled robots. The scientific goals of this research are to develop a new visual servo control methodology that: (1) adapts for the unknown camera calibration parameters (e.g., focal length, scaling factors, camera position and orientation) and the physical parameters of the robotic system (e.g., mass, inertia, friction), (2) compensates for unknown depth information (extract 3D information from the 2D image), and (3) enables multi-uncalibrated cameras to be used as a means to provide a larger field-of-view. Nonlinear Lyapunov-based techniques are being used to overcome the complex control issues and alleviate many of the restrictive assumptions that impact current visual servo controlled robotic systems. The potential relevance of this control methodology will be a plug-and-play visual servoing control module that can be utilized in conjunction with current technology such as feature extraction and recognition, to enable current EM robotic systems with the capabilities of increased accuracy, autonomy, and robustness, with a larger field of view (and hence a larger workspace). These capabilities will enable EM robots to significantly accelerate D and D operations by providing for improved robot autonomy and increased worker productivity, while also reducing the associated costs, removing the human operator from the hazardous environments, and reducing the burden and skill of the human operators

Stability and servo-control of the crystal pulling process

International Nuclear Information System (INIS)

Johansen, T.H.

1990-11-01

The paper analyzes why the crystal pulling process needs servo-control, and how it can be implemented. Special emphasis is put on the fundamental question of inherent stability, and how to interpret the signal from a balance when the weighing method is used for cystal diameter detection. 15 refs., 13 figs

A low-cost, FPGA-based servo controller with lock-in amplifier

International Nuclear Information System (INIS)

Yang, G; Barry, J F; Shuman, E S; Steinecker, M H; DeMille, D

2012-01-01

We describe the design and implementation of a low-cost, FPGA-based servo controller with an integrated waveform synthesizer and lock-in amplifier. This system has been designed with the specific application of laser frequency locking in mind but should be adaptable to a variety of other purposes as well. The system incorporates an onboard waveform synthesizer, a lock-in amplifier, two channels of proportional-integral (PI) servo control, and a ramp generator on a single FPGA chip. The system is based on an inexpensive, off-the-shelf FPGA evaluation board with a wide variety of available accessories, allowing the system to interface with standard laser controllers and detectors while minimizing the use of custom hardware and electronics. Gains, filter constants, and other relevant parameters are adjustable via onboard knobs and switches. These parameters and other information are displayed to the user via an integrated LCD, allowing full operation of the device without an accompanying computer. We demonstrate the performance of the system in a test setup, in which the frequency of a tunable external-cavity diode laser (ECDL) is locked to a resonant optical transmission peak of a Fabry-Perot cavity. In this setup, we achieve a total servo-loop bandwidth of ∼ 7 kHz and achieve locking of the ECDL to the cavity with a full-width-at-half-maximum (FWHM) linewidth of ∼ 200 kHz.

Parametric model of servo-hydraulic actuator coupled with a nonlinear system: Experimental validation

Science.gov (United States)

Maghareh, Amin; Silva, Christian E.; Dyke, Shirley J.

2018-05-01

Hydraulic actuators play a key role in experimental structural dynamics. In a previous study, a physics-based model for a servo-hydraulic actuator coupled with a nonlinear physical system was developed. Later, this dynamical model was transformed into controllable canonical form for position tracking control purposes. For this study, a nonlinear device is designed and fabricated to exhibit various nonlinear force-displacement profiles depending on the initial condition and the type of materials used as replaceable coupons. Using this nonlinear system, the controllable canonical dynamical model is experimentally validated for a servo-hydraulic actuator coupled with a nonlinear physical system.

Characteristic Modeling and Control of Servo Systems with Backlash and Friction

Directory of Open Access Journals (Sweden)

Yifei Wu

2014-01-01

Full Text Available A novel approach for modeling and control of servo systems with backlash and friction is proposed based on the characteristic model. Firstly, to deal with friction-induced nonlinearities, a smooth Stribeck friction model is introduced. The backlash is modeled by a continuous and derivable mathematical function. Secondly, a characteristic model in the form of a second-order slowly time-varying difference equation is established and verified by simulations. Thirdly, a composite controller including the golden-section adaptive control law and the integral control law is designed and the stability of the closed-loop system is analyzed. The simulation and experimental results show that the proposed control scheme is effective and can improve the steady-state precision and the dynamic performance of the servo system with backlash and friction.

Control Servo-Visual de un Robot Manipulador Planar Basado en Pasividad

Directory of Open Access Journals (Sweden)

Carlos Soria

2008-10-01

Full Text Available Resumen: En este trabajo se diseña un controlador servo visual basado en la propiedad de pasividad del sistema visual. Se propone un regulador con ganancias de control variables, de tal manera que se evita la saturación de los actuadores y al mismo tiempo presenta la capacidad de corregir errores de pequeña magnitud. Asimismo el diseno se hace tenieñdo en cuenta el desempeño L2, a fin de darle capacidad de seguimiento de objetos en movimiento, con un error de control pequeño. Se muestran resultados experimentales realizados en un robot manipulador industrial tipo planar para verificar el cumplimiento de los objetivos del controlador propuesto. Palabras Clave: robot manipulador industrial, control servo visual, control no lineal, pasividad

Ritual, tiempo y espacio sagrado en el budismo zen argentino

Directory of Open Access Journals (Sweden)

Catón Eduardo Carini

2010-07-01

Full Text Available El budismo zen es una religión oriental que desde hace varias décadas se ha esparcido en numerosos países occidentales, incluido la Argentina. Una característica notable de su vida comunitaria es la compleja ritualización de sus prácticas cotidianas. En nuestra aproximación a la dimensión ritual del zen indagaremos la forma en que ésta contribuye a crear un tiempo y un espacio sagrado y observaremos cómo estas prácticas son consideradas por los propios miembros del grupo como un recurso pedagógico que posibilita entrenarse en una diferente manera de estar en el mundo, de vivirse y percibirse tanto a ellos mismos como a los demás. De modo que algunos elementos del complejo ritual zen juegan un rol de primera importancia como una tecnología del ser.Zen Buddhism is an oriental religion that since several decades has expanded in various western countries, Argentina being one of them. The complex ritualization of its everyday practices is a considerable characteristic of Zen Buddhist community life. In our exploration of the ritual dimension of Zen, first we will investigate how this contributes to the creation of a sacred time and place. After this, we will show how ritual practices are considered a pedagogic recourse by group members; a means to make possible their training of a different way of being in the world, of experimenting, living and perceiving both themselves and others in a different way. Some elements of the often complex Zen ritual play a highly important part as technologies of the self.

Active stabilization of a rapidly chirped laser by an optoelectronic digital servo-loop control.

Science.gov (United States)

Gorju, G; Jucha, A; Jain, A; Crozatier, V; Lorgeré, I; Le Gouët, J-L; Bretenaker, F; Colice, M

2007-03-01

We propose and demonstrate a novel active stabilization scheme for wide and fast frequency chirps. The system measures the laser instantaneous frequency deviation from a perfectly linear chirp, thanks to a digital phase detection process, and provides an error signal that is used to servo-loop control the chirped laser. This way, the frequency errors affecting a laser scan over 10 GHz on the millisecond timescale are drastically reduced below 100 kHz. This active optoelectronic digital servo-loop control opens new and interesting perspectives in fields where rapidly chirped lasers are crucial.

Recent results in visual servoing

Science.gov (United States)

Chaumette, François

2008-06-01

Visual servoing techniques consist in using the data provided by a vision sensor in order to control the motions of a dynamic system. Such systems are usually robot arms, mobile robots, aerial robots,… but can also be virtual robots for applications in computer animation, or even a virtual camera for applications in computer vision and augmented reality. A large variety of positioning tasks, or mobile target tracking, can be implemented by controlling from one to all the degrees of freedom of the system. Whatever the sensor configuration, which can vary from one on-board camera on the robot end-effector to several free-standing cameras, a set of visual features has to be selected at best from the image measurements available, allowing to control the degrees of freedom desired. A control law has also to be designed so that these visual features reach a desired value, defining a correct realization of the task. With a vision sensor providing 2D measurements, potential visual features are numerous, since as well 2D data (coordinates of feature points in the image, moments, …) as 3D data provided by a localization algorithm exploiting the extracted 2D measurements can be considered. It is also possible to combine 2D and 3D visual features to take the advantages of each approach while avoiding their respective drawbacks. From the selected visual features, the behavior of the system will have particular properties as for stability, robustness with respect to noise or to calibration errors, robot 3D trajectory, etc. The talk will present the main basic aspects of visual servoing, as well as technical advances obtained recently in the field inside the Lagadic group at INRIA/INRISA Rennes. Several application results will be also described.

Fault Diagnosis for Hydraulic Servo System Using Compressed Random Subspace Based ReliefF

Directory of Open Access Journals (Sweden)

Yu Ding

2018-01-01

Full Text Available Playing an important role in electromechanical systems, hydraulic servo system is crucial to mechanical systems like engineering machinery, metallurgical machinery, ships, and other equipment. Fault diagnosis based on monitoring and sensory signals plays an important role in avoiding catastrophic accidents and enormous economic losses. This study presents a fault diagnosis scheme for hydraulic servo system using compressed random subspace based ReliefF (CRSR method. From the point of view of feature selection, the scheme utilizes CRSR method to determine the most stable feature combination that contains the most adequate information simultaneously. Based on the feature selection structure of ReliefF, CRSR employs feature integration rules in the compressed domain. Meanwhile, CRSR substitutes information entropy and fuzzy membership for traditional distance measurement index. The proposed CRSR method is able to enhance the robustness of the feature information against interference while selecting the feature combination with balanced information expressing ability. To demonstrate the effectiveness of the proposed CRSR method, a hydraulic servo system joint simulation model is constructed by HyPneu and Simulink, and three fault modes are injected to generate the validation data.

Concurrent image-based visual servoing with adaptive zooming for non-cooperative rendezvous maneuvers

Science.gov (United States)

Pomares, Jorge; Felicetti, Leonard; Pérez, Javier; Emami, M. Reza

2018-02-01

An image-based servo controller for the guidance of a spacecraft during non-cooperative rendezvous is presented in this paper. The controller directly utilizes the visual features from image frames of a target spacecraft for computing both attitude and orbital maneuvers concurrently. The utilization of adaptive optics, such as zooming cameras, is also addressed through developing an invariant-image servo controller. The controller allows for performing rendezvous maneuvers independently from the adjustments of the camera focal length, improving the performance and versatility of maneuvers. The stability of the proposed control scheme is proven analytically in the invariant space, and its viability is explored through numerical simulations.

Image-based visual servo control using the port-Hamiltonian Approach

NARCIS (Netherlands)

Muñoz Arias, Mauricio; El Hawwary, Mohamed; Scherpen, Jacquelien M.A.

2015-01-01

This work is devoted to an image-based visual servo control strategy for standard mechanical systems in the port-Hamiltonian framework. We utilize a change of variables that transforms the port-Hamiltonian system into one with constant mass-inertia matrix, and we use an interaction matrix that

Smart Rotor Modeling: Aero-Servo-Elastic Modeling of a Smart Rotor with Adaptive Trailing Edge Flaps

DEFF Research Database (Denmark)

Bergami, Leonardo

the trailing edge flap deflection to actively reduce the fatigue loads on the structure. The performance of the smart rotor configuration and its control algorithms are finally quantified by aero-servo-elastic simulations of the smart rotor turbine operating in a standard turbulent wind field.......This book presents the formulation of an aero-servo-elastic model for a wind turbine rotor equipped with Adaptive Trailing Edge Flaps (ATEF), a smart rotor configuration. As the name suggests, an aero-servo-elastic model consists of three main components: an aerodynamic model, a structural model......, and a control model. The book first presents an engineering type of aerodynamic model that accounts for the dynamic effects of flap deflection. The aerodynamic model is implemented in a Blade Element Momentum framework, and coupled with a multi-body structural model in the aero-servoelastic simulation code HAWC...

Robust control system for belt continuously variable transmission; Robust seigyo wo tekiyoshita mudan hensokuki no hensokuhi servo kei no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Adachi, K; Wakahara, T; Shimanaka, S; Yamamoto, M; Oshidari, T [Nissan Motor Co. Ltd., Tokyo (Japan)

1997-10-01

The continuously variable transmission control system consists of generation of a desired gear ratio and a servo gear ratio system. The servo gear ratio system must provide the desired response at all times without being influenced by external disturbances. These include oil pressure as well as variation in performance due to operating conditions or changes occurring with us. We have developed the servo gear ratio system incorporating a robust model matching method, which enables the belt continuously variable transmission to satisfy this performance requirement. 2 refs., 9 figs.

Ultrasound image based visual servoing for moving target ablation by high intensity focused ultrasound.

Science.gov (United States)

Seo, Joonho; Koizumi, Norihiro; Mitsuishi, Mamoru; Sugita, Naohiko

2017-12-01

Although high intensity focused ultrasound (HIFU) is a promising technology for tumor treatment, a moving abdominal target is still a challenge in current HIFU systems. In particular, respiratory-induced organ motion can reduce the treatment efficiency and negatively influence the treatment result. In this research, we present: (1) a methodology for integration of ultrasound (US) image based visual servoing in a HIFU system; and (2) the experimental results obtained using the developed system. In the visual servoing system, target motion is monitored by biplane US imaging and tracked in real time (40 Hz) by registration with a preoperative 3D model. The distance between the target and the current HIFU focal position is calculated in every US frame and a three-axis robot physically compensates for differences. Because simultaneous HIFU irradiation disturbs US target imaging, a sophisticated interlacing strategy was constructed. In the experiments, respiratory-induced organ motion was simulated in a water tank with a linear actuator and kidney-shaped phantom model. Motion compensation with HIFU irradiation was applied to the moving phantom model. Based on the experimental results, visual servoing exhibited a motion compensation accuracy of 1.7 mm (RMS) on average. Moreover, the integrated system could make a spherical HIFU-ablated lesion in the desired position of the respiratory-moving phantom model. We have demonstrated the feasibility of our US image based visual servoing technique in a HIFU system for moving target treatment. © 2016 The Authors The International Journal of Medical Robotics and Computer Assisted Surgery Published by John Wiley & Sons Ltd.

Aero-servo-viscoelasticity theory: Lifting surfaces, plates, velocity transients, flutter, and instability

Science.gov (United States)

Merrett, Craig G.

Modern flight vehicles are fabricated from composite materials resulting in flexible structures that behave differently from the more traditional elastic metal structures. Composite materials offer a number of advantages compared to metals, such as improved strength to mass ratio, and intentional material property anisotropy. Flexible aircraft structures date from the Wright brothers' first aircraft with fabric covered wooden frames. The flexibility of the structure was used to warp the lifting surface for flight control, a concept that has reappeared as aircraft morphing. These early structures occasionally exhibited undesirable characteristics during flight such as interactions between the empennage and the aft fuselage, or control problems with the elevators. The research to discover the cause and correction of these undesirable characteristics formed the first foray into the field of aeroelasticity. Aeroelasticity is the intersection and interaction between aerodynamics, elasticity, and inertia or dynamics. Aeroelasticity is well suited for metal aircraft, but requires expansion to improve its applicability to composite vehicles. The first is a change from elasticity to viscoelasticity to more accurately capture the solid mechanics of the composite material. The second change is to include control systems. While the inclusion of control systems in aeroelasticity lead to aero-servo-elasticity, more control possibilities exist for a viscoelastic composite material. As an example, during the lay-up of carbon-epoxy plies, piezoelectric control patches are inserted between different plies to give a variety of control options. The expanded field is called aero-servo-viscoelasticity. The phenomena of interest in aero-servo-viscoelasticity are best classified according to the type of structure considered, either a lifting surface or a panel, and the type of dynamic stability present. For both types of structures, the governing equations are integral

A servo controlled gradient loading triaxial model test system for deep-buried cavern

Energy Technology Data Exchange (ETDEWEB)

Chen, Xu-guang [College of Engineering, Ocean University of China, Qingdao 266100 (China); Shandong Provincial Key Laboratory of Ocean Engineering, Qingdao 266100 (China); Research Center of Geotechnical and Structural Engineering, Shandong University, Jinan 250061 (China); Zhang, Qiang-yong; Li, Shu-cai [Research Center of Geotechnical and Structural Engineering, Shandong University, Jinan 250061 (China)

2015-10-15

A servo controlled gradient loading model test system is developed to simulate the gradient geostress in deep-buried cavern. This system consists of the gradient loading apparatus, the digital servo control device, and the measurement system. Among them, the gradient loading apparatus is the main component which is used for exerting load onto the model. This loading apparatus is placed inside the counterforce wall/beam and is divided to several different loading zones, with each loading zone independently controlled. This design enables the gradient loading. Hence, the “real” geostress field surrounding the deep-buried cavern can be simulated. The loading or unloading process can be controlled by the human-computer interaction machines, i.e., the digital servo control system. It realizes the automation and visualization of model loading/unloading. In addition, this digital servo could control and regulate hydraulic loading instantaneously, which stabilizes the geostress onto the model over a long term. During the loading procedure, the collision between two adjacent loading platens is also eliminated by developing a guide frame. This collision phenomenon is induced by the volume shrinkage of the model when compressed in true 3D state. In addition, several accurate measurements, including the optical and grating-based method, are adopted to monitor the small deformation of the model. Hence, the distortion of the model could be accurately measured. In order to validate the performance of this innovative model test system, a 3D geomechanical test was conducted on a simulated deep-buried underground reservoir. The result shows that the radial convergence increases rapidly with the release of the stress in the reservoir. Moreover, the deformation increases with the increase of the gas production rate. This observation is consistence with field observation in petroleum engineering. The system is therefore capable of testing deep-buried engineering structures.

Image-Based Visual Servoing for Robotic Systems: A Nonlinear Lyapunov-Based Control Approach

International Nuclear Information System (INIS)

Dixon, Warren

2004-01-01

There is significant motivation to provide robotic systems with improved autonomy as a means to significantly accelerate deactivation and decommissioning (DandD) operations while also reducing the associated costs, removing human operators from hazardous environments, and reducing the required burden and skill of human operators. To achieve improved autonomy, this project focused on the basic science challenges leading to the development of visual servo controllers. The challenge in developing these controllers is that a camera provides 2-dimensional image information about the 3-dimensional Euclidean-space through a perspective (range dependent) projection that can be corrupted by uncertainty in the camera calibration matrix and by disturbances such as nonlinear radial distortion. Disturbances in this relationship (i.e., corruption in the sensor information) propagate erroneous information to the feedback controller of the robot, leading to potentially unpredictable task execution. This research project focused on the development of a visual servo control methodology that targets compensating for disturbances in the camera model (i.e., camera calibration and the recovery of range information) as a means to achieve predictable response by the robotic system operating in unstructured environments. The fundamental idea is to use nonlinear Lyapunov-based techniques along with photogrammetry methods to overcome the complex control issues and alleviate many of the restrictive assumptions that impact current robotic applications. The outcome of this control methodology is a plug-and-play visual servoing control module that can be utilized in conjunction with current technology such as feature recognition and extraction to enable robotic systems with the capabilities of increased accuracy, autonomy, and robustness, with a larger field of view (and hence a larger workspace). The developed methodology has been reported in numerous peer-reviewed publications and the

A servo controlled gradient loading triaxial model test system for deep-buried cavern.

Science.gov (United States)

Chen, Xu-guang; Zhang, Qiang-yong; Li, Shu-cai

2015-10-01

A servo controlled gradient loading model test system is developed to simulate the gradient geostress in deep-buried cavern. This system consists of the gradient loading apparatus, the digital servo control device, and the measurement system. Among them, the gradient loading apparatus is the main component which is used for exerting load onto the model. This loading apparatus is placed inside the counterforce wall/beam and is divided to several different loading zones, with each loading zone independently controlled. This design enables the gradient loading. Hence, the "real" geostress field surrounding the deep-buried cavern can be simulated. The loading or unloading process can be controlled by the human-computer interaction machines, i.e., the digital servo control system. It realizes the automation and visualization of model loading/unloading. In addition, this digital servo could control and regulate hydraulic loading instantaneously, which stabilizes the geostress onto the model over a long term. During the loading procedure, the collision between two adjacent loading platens is also eliminated by developing a guide frame. This collision phenomenon is induced by the volume shrinkage of the model when compressed in true 3D state. In addition, several accurate measurements, including the optical and grating-based method, are adopted to monitor the small deformation of the model. Hence, the distortion of the model could be accurately measured. In order to validate the performance of this innovative model test system, a 3D geomechanical test was conducted on a simulated deep-buried underground reservoir. The result shows that the radial convergence increases rapidly with the release of the stress in the reservoir. Moreover, the deformation increases with the increase of the gas production rate. This observation is consistence with field observation in petroleum engineering. The system is therefore capable of testing deep-buried engineering structures.

A servo controlled gradient loading triaxial model test system for deep-buried cavern

International Nuclear Information System (INIS)

Chen, Xu-guang; Zhang, Qiang-yong; Li, Shu-cai

2015-01-01

A servo controlled gradient loading model test system is developed to simulate the gradient geostress in deep-buried cavern. This system consists of the gradient loading apparatus, the digital servo control device, and the measurement system. Among them, the gradient loading apparatus is the main component which is used for exerting load onto the model. This loading apparatus is placed inside the counterforce wall/beam and is divided to several different loading zones, with each loading zone independently controlled. This design enables the gradient loading. Hence, the “real” geostress field surrounding the deep-buried cavern can be simulated. The loading or unloading process can be controlled by the human-computer interaction machines, i.e., the digital servo control system. It realizes the automation and visualization of model loading/unloading. In addition, this digital servo could control and regulate hydraulic loading instantaneously, which stabilizes the geostress onto the model over a long term. During the loading procedure, the collision between two adjacent loading platens is also eliminated by developing a guide frame. This collision phenomenon is induced by the volume shrinkage of the model when compressed in true 3D state. In addition, several accurate measurements, including the optical and grating-based method, are adopted to monitor the small deformation of the model. Hence, the distortion of the model could be accurately measured. In order to validate the performance of this innovative model test system, a 3D geomechanical test was conducted on a simulated deep-buried underground reservoir. The result shows that the radial convergence increases rapidly with the release of the stress in the reservoir. Moreover, the deformation increases with the increase of the gas production rate. This observation is consistence with field observation in petroleum engineering. The system is therefore capable of testing deep-buried engineering structures

A Matlab/Simulink-Based Interactive Module for Servo Systems Learning

Science.gov (United States)

Aliane, N.

2010-01-01

This paper presents an interactive module for learning both the fundamental and practical issues of servo systems. This module, developed using Simulink in conjunction with the Matlab graphical user interface (Matlab-GUI) tool, is used to supplement conventional lectures in control engineering and robotics subjects. First, the paper introduces the…

Evaluation and compensation of steady gas flow force on the high-pressure electro-pneumatic servo valve direct-driven by voice coil motor

International Nuclear Information System (INIS)

Li, Baoren; Gao, Longlong; Yang, Gang

2013-01-01

Highlights: ► A novel energy saving high-pressure electro-pneumatic servo valve is presented. ► An evaluated method for steady gas flow forces on pneumatic valves is proposed. ► Gas jet angles at the orifices for the valve are larger than 69° commonly used. ► The steady gas flow force is strongly nonlinear with valve opening. ► The steady gas flow force is compensated and the aim at energy saving is realized. - Abstract: A novel voice coil motor (VCM) direct drive single stage high-pressure pneumatic servo valve is designed, and then the steady gas flow force acting on the spool of the servo valve is investigated by numerical simulation and experimental methods in this paper. At present, many studies about flow force are concentrated mainly on hydraulic valves, but rarely on pneumatic valves. However, the velocity of gas is up to sonic when high-pressure gas flows through the servo valve orifice. And therefore, the steady gas flow force, generated by high pressure and high speed gas flow, cannot be neglected and is an important disturbance for the VCM direct-drive single stage high-pressure pneumatic servo valve. Consequently, the numerical simulation with computational fluid dynamics (CFD) is adopted to analyze the flow filed, jet angles, and steady gas flow forces for the servo valve with different valve openings and inlet pressures. The experimental study is performed to evaluate and confirm the numerical analysis. Then the compensated approach is proposed to reduce the steady gas flow force for the servo valve, changing the angle of non-metering port designed in the valve sleeve to the spool axis. The results demonstrate that the presented numerical analysis method is validated, the gas jet angle for the servo valve orifice is more than 69° and varies with different spool openings, and the steady gas flow force is nonlinear with valve opening and linear with inlet pressure when the outlet boundary is atmospheric pressure. Moreover, the steady gas

Investigation on Superior Performance by Fractional Controller for Cart-Servo Laboratory Set-Up

Directory of Open Access Journals (Sweden)

Ameya Anil Kesarkar

2014-01-01

Full Text Available In this paper, an investigation is made on the superiority of fractional PID controller (PI^alpha D^beta over conventional PID for the cart-servo laboratory set-up. The designed controllers are optimum in the sense of Integral Absolute Error (IAE and Integral Square Error (ISE. The paper contributes in three aspects: 1 Acquiring nonlinear mathematical model for the cart-servo laboratory set-up, 2 Designing fractional and integer order PID for minimizing IAE, ISE, 3 Analyzing the performance of designed controllers for simulated plant model as well as real plant. The results show a significantly superior performance by PI^alpha D^beta as compared to the conventional PID controller.

Enhancement of tracking performance in electro-optical system based on servo control algorithm

Science.gov (United States)

Choi, WooJin; Kim, SungSu; Jung, DaeYoon; Seo, HyoungKyu

2017-10-01

Modern electro-optical surveillance and reconnaissance systems require tracking capability to get exact images of target or to accurately direct the line of sight to target which is moving or still. This leads to the tracking system composed of image based tracking algorithm and servo control algorithm. In this study, we focus on the servo control function to minimize the overshoot in the tracking motion and do not miss the target. The scheme is to limit acceleration and velocity parameters in the tracking controller, depending on the target state information in the image. We implement the proposed techniques by creating a system model of DIRCM and simulate the same environment, validate the performance on the actual equipment.

Adaptive Sliding Mode Robust Control for Virtual Compound-Axis Servo System

Directory of Open Access Journals (Sweden)

Yan Ren

2013-01-01

Full Text Available A structure mode of virtual compound-axis servo system is proposed to improve the tracking accuracy of the ordinary optoelectric tracking platform. It is based on the structure and principles of compound-axis servo system. A hybrid position control scheme combining the PD controller and feed-forward controller is used in subsystem to track the tracking error of the main system. This paper analyzes the influences of the equivalent disturbance in main system and proposes an adaptive sliding mode robust control method based on the improved disturbance observer. The sliding mode technique helps this disturbance observer to deal with the uncompensated disturbance in high frequency by making use of the rapid switching control value, which is based on the subtle error of disturbance estimation. Besides, the high-frequency chattering is alleviated effectively in this proposal. The effectiveness of the proposal is confirmed by experiments on optoelectric tracking platform.

La iglesia del Sagrado Corazón de Jesús en Elche. Un ejemplo de la introducción del hormigón en la arquitectura sacra

OpenAIRE

Spairani Berrio, Silvia; Louis Cereceda, Miguel; Spairani-Berrio, Yolanda; Huesca Tortosa, José Antonio

2016-01-01

La iglesia del Sagrado Corazón de Jesús (Alicante, España), es quizás, el edificio proyectado por el arquitecto D. Antonio Serrano Peral cuyo valor arquitectónico es menos conocido y reconocido en el ámbito de la historia de la arquitectura de la ciudad. Sin embargo, su construcción constituye un interesante ejemplo de arquitectura sacra, como reconoció el jurado del Ministerio de Educación Nacional en 1957, en la exposición nacional de bellas artes, al conceder al arquitecto la medalla de pr...

Servo Reduces Friction In Flexure Bearing

Science.gov (United States)

Clingman, W. Dean

1991-01-01

Proposed servocontrol device reduces such resistive torques as stiction, friction, ripple, and cogging in flexure bearing described in LAR-14348, "Flexure Bearing Reduces Startup Friction". Reduces frictional "bump" torque encountered when bearing ball runs into buildup of grease on bearing race. Also used as cable follower to reduce torque caused by cable and hoses when they bend because of motion of bearing. New device includes torquer across ball race. Torquer controlled by servo striving to keep flexure at null, removing torque to outer ring. In effect, device is inner control loop reducing friction, but does not control platforms or any outer-control-loop functions.

Servo-control of water and sodium homeostasis during renal clearance measurements in conscious rats.

Science.gov (United States)

Thomsen, Klaus; Shirley, David G

2007-01-01

Servo-controlled fluid and sodium replacement during clearance studies is used in order to prevent loss of body fluid and sodium following diuretic/natriuretic procedures. However, even under control conditions, the use of this technique is sometimes associated with increases in proximal tubular fluid output (assessed by lithium clearance) and excretion rates. The present study examined the reason for these increases. The first series of experiments showed that one cause is volume overloading. This can occur if the servo system is activated from the start, i.e., during the establishment of a suitably high urine flow rate by constant infusion of hypotonic glucose solution. The second series of experiments showed that replacement of blood samples with donor blood can also lead to increases in fractional lithium excretion and accompanying increases in water and sodium excretion, a problem not seen when blood samples are replaced with the animal's own red blood cells resuspended in isotonic saline. When these pitfalls are avoided, servo-controlled sodium and fluid replacement is a reliable technique that makes it possible to study the effects of natriuretic and/or diuretic stimuli without interference from unwanted changes in extracellular volume. 2007 S. Karger AG, Basel

Servo Driven Corotation: Development of AN Inertial Clock.

Science.gov (United States)

Cheung, Wah-Kwan Stephen

An inertial clock to test non-metricity of gravity is proposed here. A first, room-temperature, servo corotation -protected, double magnetically suspended precision rotor system is developed for this purpose. The specific goal was to exhibit the properties of such a clock in its entirety at whatever level of precision was achievable. A monolithic system has been completed for these preliminary studies. It includes particular development of individual experimental sub-systems (a hybrid double magnetic suspension; a diffusion pumping system; a microcomputer -controlled eddy-current drive system; and the angular period measuring schemes for the doubly suspended rotors). Double magnetic suspension had been investigated by Beams for other purposes. The upper transducer is optical but parametrized and the lower transducer employs the frequency modulation characteristic of a LC tank circuit. The doubly suspended rotors corotate so that the upper rotor is servoed to rotate at the same angular velocity as that of the lower rotor. This creates a "drag free" environment for the lower rotor and effectively eliminates the gas drag on the lower rotor. Consequently, the decay time constant of the lower rotor increases. With other means of protection, the lower rotor will then, with perfect system operation, suffer no drag and therefore become the inertial time keeper. A commercial microcomputer is introduced to execute the servo-corotation. The tests thus far are, with one exception, run at atmospheric pressure. An idealized analysis for open and closed loop corotation is shown. Such analysis includes only the viscous drag acting on the corotating rotors. The analysis suggests that angular position control be added to the present feedback drive which is of derivative nature only. Open and closed corotation runs show that a strong torsional coupling besides that of the gas drag exists between the rotors. When misalignment of the support pole pieces is deliberately made significant

Model-based specification, analysis and synthesis of servo controllers for lithoscanners

NARCIS (Netherlands)

Schiffelers, R.; Alberts, W.; Voeten, J.P.M.

2012-01-01

ASML is the world's leading provider of complex lithography systems for the semiconductor industry. Such systems consist of numerous servo control systems. To design such control systems, a multi-disciplinary model-based development environment has been developed. It is based on a set of domain

Frequency doubled dye laser with a servo-tuned crystal

Energy Technology Data Exchange (ETDEWEB)

Kuhl, J; Spitschan, H

1975-01-01

Spectral tuning of the uv output of a frequency doubled dye laser was successfully controlled by a servo motor system which tilts the nonlinear crystal appropriate for phase-matched second harmonic generation while the dye laser emission wavelength is tuned. The spatial direction of the generated uv beam was used as the regulating signal. The feasibility of this technique for spectroscopic applications was successfully tested.

Cine-servo lens technology for 4K broadcast and cinematography

Science.gov (United States)

Nurishi, Ryuji; Wakazono, Tsuyoshi; Usui, Fumiaki

2015-09-01

Central to the rapid evolution of 4K image capture technology in the past few years, deployment of large-format cameras with Super35mm Single Sensors is increasing in TV production for diverse shows such as dramas, documentaries, wildlife, and sports. While large format image capture has been the standard in the cinema world for quite some time, the recent experiences within the broadcast industry have revealed a variety of requirement differences for large format lenses compared to those of the cinema industry. A typical requirement for a broadcast lens is a considerably higher zoom ratio in order to avoid changing lenses in the middle of a live event, which is mostly not the case for traditional cinema productions. Another example is the need for compact size, light weight, and servo operability for a single camera operator shooting in a shoulder-mount ENG style. On the other hand, there are new requirements that are common to both worlds, such as smooth and seamless change in angle of view throughout the long zoom range, which potentially offers new image expression that never existed in the past. This paper will discuss the requirements from the two industries of cinema and broadcast, while at the same time introducing the new technologies and new optical design concepts applied to our latest "CINE-SERVO" lens series which presently consists of two models, CN7x17KAS-S and CN20x50IAS-H. It will further explain how Canon has realized 4K optical performance and fast servo control while simultaneously achieving compact size, light weight and high zoom ratio, by referring to patent-pending technologies such as the optical power layout, lens construction, and glass material combinations.

Dynamic modeling and experiment of a new type of parallel servo press considering gravity counterbalance

Science.gov (United States)

He, Jun; Gao, Feng; Bai, Yongjun; Wu, Shengfu

2013-11-01

The large capacity servo press is traditionally realized by means of redundant actuation, however there exist the over-constraint problem and interference among actuators, which increases the control difficulty and the product cost. A new type of press mechanism with parallel topology is presented to develop the mechanical servo press with high stamping capacity. The dynamic model considering gravity counterbalance is proposed based on the virtual work principle, and then the effect of counterbalance cylinder on the dynamic performance of the servo press is studied. It is found that the motor torque required to operate the press is a lot less than the others when the ratio of the counterbalance force to the gravity of ram is in the vicinity of 1.0. The stamping force of the real press prototype can reach up to 25 MN on the position of 13 mm away from the bottom dead center. The typical deep-drawing process with 1 200 mm stroke at 8 strokes per minute is proposed by means of five order polynomial. On this process condition, the driving torques are calculated based on the above dynamic model and the torque measuring test is also carried out on the prototype. It is shown that the curve trend of calculation torque is consistent to the measured result and that the average error is less than 15%. The parallel mechanism is introduced into the development of large capacity servo press to avoid the over-constraint and interference of traditional redundant actuation, and its dynamic characteristics with gravity counterbalance are presented.

Efficient control of servo pneumatic actuator system utilizing by-pass ...

Indian Academy of Sciences (India)

The issue of energy saving nowadays is very crucial. Pneumatic systems, constituting an important segment of almost every industry, represent large energy consumers. Also, a significant problem with servo pneumatic actuators is achieving accuracy in positioning. The higher the positioning accuracy, the higher the ...

Os sacrifícios da carne: a morte do gado e a produção dos banquetes nas folias de Urucuia, MG

Directory of Open Access Journals (Sweden)

Luzimar Paulo Pereira

2012-01-01

Full Text Available A morte do gado nas folias de Urucuia é um processo sacrificial e como tal realiza um duplo movimento de sacralização: de um lado, o boi é envolto por uma aura sagrada que o transforma em propriedade dos santos; de outro, suas carnes oferecidas em banquete comunicam de "cima para baixo" os poderes sagrados associados à entidade religiosa. Neste artigo, estudo os mecanismos responsáveis pela constituição da unidade sacrificial a partir das operações simbólicas ascendentes e descendentes relativas aos bois e à comida festiva. A totalidade do sacrifício se constrói a partir da ideia de carne de gado. Entidade liminar entre o animal vivo e o alimento pronto, ela realiza as mediações entre os planos naturais, sociais e sobrenaturais mobilizados durante os festejos.

Investigation of the low flux servo-controlled limit of a co-phased interferometer

Science.gov (United States)

Damé, Luc; Derrien, Marc; Kozlowski, Mathias; Merdjane, Mohamed

2018-04-01

This paper, "Investigation of the low flux servo-controlled limit of a co-phased interferometer," was presented as part of International Conference on Space Optics—ICSO 1997, held in Toulouse, France.

Analysis of an controller design for an electro-hydraulic servo pressure regulator

DEFF Research Database (Denmark)

Pedersen, Henrik C.; Andersen, Torben Ole; Madsen, A. M.

2009-01-01

Mobile hydraulics is in a transition phase, where electronic sensors and digital signal processors are starting to become standard on a high number of machines, hereby replacing hydraulic pilot lines and oering new possibilities with regard to both control and feasibility. For controlling some...... of the existing hydraulic components there are, however, still a need for being able to generate a hydraulic pilot pressure, as e.g. almost all open-circuit pumps are hydraulically controlled. The focus of the current paper is therefore on the analysis and controller design an electro-hydraulic servo pressure...... regulator, which generates a hydraulic LS-pressure based on an electrical reference, hereby synergistically integrating knowledge from all parts of the mechatronics area. The servo pressure regulator is used to generate the LS-signal for a variable displacement pump, and the paper rst presents...

High precision tracking control of a servo gantry with dynamic friction compensation.

Science.gov (United States)

Zhang, Yangming; Yan, Peng; Zhang, Zhen

2016-05-01

This paper is concerned with the tracking control problem of a voice coil motor (VCM) actuated servo gantry system. By utilizing an adaptive control technique combined with a sliding mode approach, an adaptive sliding mode control (ASMC) law with friction compensation scheme is proposed in presence of both frictions and external disturbances. Based on the LuGre dynamic friction model, a dual-observer structure is used to estimate the unmeasurable friction state, and an adaptive control law is synthesized to effectively handle the unknown friction model parameters as well as the bound of the disturbances. Moreover, the proposed control law is also implemented on a VCM servo gantry system for motion tracking. Simulations and experimental results demonstrate good tracking performance, which outperform traditional control approaches. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Lung function studied by servo-controlled ventilator and respiratory mass spectrometer

International Nuclear Information System (INIS)

Piiper, J.

1987-01-01

The gas exchange function of lungs is studied. The gas concentration, measured by mass spectrometry and the lung volume and rate of change of lung volume are discussed. A servo-controlled ventilator is presented. Several experimental projects performed on anesthetized paralyzed dogs are reported. (M.A.C.) [pt

Analysis of High Speed Jets Produced by a Servo Tube Driven Liquid Jet Injector

Science.gov (United States)

Portaro, Rocco; Ng, Hoi Dick

2017-11-01

In today's healthcare environment many types of medication must be administered through the use of hypodermic needles. Although this practice has been in use for many years, drawbacks such as accidental needle stick injuries, transmission of deadly viruses and bio-hazardous waste are still present. This study focuses on improving a needle free technology known as liquid jet injection, through the implementation of a linear servo tube actuator for the construction of a fully closed loop liquid jet injection system. This device has the ability to deliver both micro- and macro- molecules, high viscosity fluids whilst providing real time control of the jet pressure profile for accurate depth and dispersion control. The experiments are conducted using a prototype that consists of a 3 kW servo tube actuator, coupled to a specially designed injection head allowing nozzle size and injection volume to be varied. The device is controlled via a high speed servo amplifier and FPGA. The high speed jets emanating from the injector are assessed via high speed photography and through the use of a force transducer. Preliminary results indicate that the system allows for accurate shaping of the jet pressure profile, making it possible to target different tissue depths/types accurately.

Strong stabilization servo controller with optimization of performance criteria.

Science.gov (United States)

Sarjaš, Andrej; Svečko, Rajko; Chowdhury, Amor

2011-07-01

Synthesis of a simple robust controller with a pole placement technique and a H(∞) metrics is the method used for control of a servo mechanism with BLDC and BDC electric motors. The method includes solving a polynomial equation on the basis of the chosen characteristic polynomial using the Manabe standard polynomial form and parametric solutions. Parametric solutions are introduced directly into the structure of the servo controller. On the basis of the chosen parametric solutions the robustness of a closed-loop system is assessed through uncertainty models and assessment of the norm ‖•‖(∞). The design procedure and the optimization are performed with a genetic algorithm differential evolution - DE. The DE optimization method determines a suboptimal solution throughout the optimization on the basis of a spectrally square polynomial and Šiljak's absolute stability test. The stability of the designed controller during the optimization is being checked with Lipatov's stability condition. Both utilized approaches: Šiljak's test and Lipatov's condition, check the robustness and stability characteristics on the basis of the polynomial's coefficients, and are very convenient for automated design of closed-loop control and for application in optimization algorithms such as DE. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Design and performance characteristic analysis of servo valve-type water hydraulic poppet valve

International Nuclear Information System (INIS)

Park, Sung Hwan

2009-01-01

For water hydraulic system control, the flow or pressure control using high-speed solenoid valve controlled by PWM control method could be a good solution for prevention of internal leakage. However, since the PWM control of on-off valves cause extensive flow and pressure fluctuation, it is difficult to control the water hydraulic actuators precisely. In this study, the servo valve-type water hydraulic valve using proportional poppet as the main valve is designed and the performance characteristics of the servo valve-type water hydraulic valve are analyzed. Furthermore, it is demonstrated through experiments that a decline in control chamber pressure that follows the change of pilot flow is caused by the occurrence of cavitation around the proportional poppet, and that fundamental characteristics of the developed valve remain unaffected by the occurrence of cavitation

Feature tracking for visual servo based range regulation on a mobile robot

CSIR Research Space (South Africa)

Burke, Michael G

2009-11-01

Full Text Available This poster presents a visual servo approach to straight line range and velocity regulation. The difference in velocity between a lead mobile robot and a follower is regulated through velocity control of the follower, in order to maintain a constant...

Development of a Control System for PRIDE Remote Servo-manipulator

International Nuclear Information System (INIS)

Lee, Jong Kwang; Park, Byung Suk; Lee, Hyo Jik; Kim, Kyung Tae; Kim, Sung Hyun; Park, Hee Sung; Kim, Young Hwan; Jung, Jae Hoo; Kim, Ki Ho; Kim, Ho Dong

2009-12-01

KAERI is developing the PRIDE(PyRoprocess Integrated inactive DEmonstration) facility to verify the integrated performance of full Pyroprocess flow. A main process cell in the PRIDE facility will be filled with argon gas which prohibits direct access by human operators. Therefore, all the operation and maintenance of the process equipment is performed remotely through a master-slave manipulation. This research focuses on the design, fabrication, and interface of a control system which integrates several hardware systems such as a dual arm master-slave servo-manipulator, a horizontally moving transporter for a master manipulator, a bridge transporter for a slave manipulator, a chain hoist, camera systems and their display system, a manual console, and a pendant, etc. Also, a bilateral force-reflection controller considering an elasticity and vibration modes of wire cable has been developed for master-slave remote manipulation. The results obtained in this study will be applied for the force-reflection control of the bridge-transported master-slave servo-manipulator system for use in the PRIDE facility. Since this research is an essential work in robotics related fields, the results would be widely used for developing power manipulators and process automation equipment

Development of a Control System for PRIDE Remote Servo-manipulator

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Kwang; Park, Byung Suk; Lee, Hyo Jik; Kim, Kyung Tae; Kim, Sung Hyun; Park, Hee Sung; Kim, Young Hwan; Jung, Jae Hoo; Kim, Ki Ho; Kim, Ho Dong

2009-12-15

KAERI is developing the PRIDE(PyRoprocess Integrated inactive DEmonstration) facility to verify the integrated performance of full Pyroprocess flow. A main process cell in the PRIDE facility will be filled with argon gas which prohibits direct access by human operators. Therefore, all the operation and maintenance of the process equipment is performed remotely through a master-slave manipulation. This research focuses on the design, fabrication, and interface of a control system which integrates several hardware systems such as a dual arm master-slave servo-manipulator, a horizontally moving transporter for a master manipulator, a bridge transporter for a slave manipulator, a chain hoist, camera systems and their display system, a manual console, and a pendant, etc. Also, a bilateral force-reflection controller considering an elasticity and vibration modes of wire cable has been developed for master-slave remote manipulation. The results obtained in this study will be applied for the force-reflection control of the bridge-transported master-slave servo-manipulator system for use in the PRIDE facility. Since this research is an essential work in robotics related fields, the results would be widely used for developing power manipulators and process automation equipment.

Chiari malformation and central sleep apnea syndrome: efficacy of treatment with adaptive servo-ventilation

Directory of Open Access Journals (Sweden)

Jorge Marques do Vale

2014-10-01

Full Text Available The Chiari malformation type I (CM-I has been associated with sleep-disordered breathing, especially central sleep apnea syndrome. We report the case of a 44-year-old female with CM-I who was referred to our sleep laboratory for suspected sleep apnea. The patient had undergone decompressive surgery 3 years prior. An arterial blood gas analysis showed hypercapnia. Polysomnography showed a respiratory disturbance index of 108 events/h, and all were central apnea events. Treatment with adaptive servo-ventilation was initiated, and central apnea was resolved. This report demonstrates the efficacy of servo-ventilation in the treatment of central sleep apnea syndrome associated with alveolar hypoventilation in a CM-I patient with a history of decompressive surgery.

Discrete Second-Order Sliding Mode Adaptive Controller Based on Characteristic Model for Servo Systems

Directory of Open Access Journals (Sweden)

Zhihong Wang

2015-01-01

Full Text Available Considering the varying inertia and load torque in high speed and high accuracy servo systems, a novel discrete second-order sliding mode adaptive controller (DSSMAC based on characteristic model is proposed, and a command observer is also designed. Firstly, the discrete characteristic model of servo systems is established. Secondly, the recursive least square algorithm is adopted to identify time-varying parameters in characteristic model, and the observer is applied to predict the command value of next sample time. Furthermore, the stability of the closed-loop system and the convergence of the observer are analyzed. The experimental results show that the proposed method not only can adapt to varying inertia and load torque, but also has good disturbance rejection ability and robustness to uncertainties.

Traços da religiosidade africana no carnaval carioca (Traces of African religiosity in carioca carnival - DOI: 10.5752/P.2175-5841.2013v11n29p53

Directory of Open Access Journals (Sweden)

José Geraldo Rocha

2013-03-01

Full Text Available As discussões a respeito do sagrado na contemporaneidade têm ganhado relevância ao considerarmos as novas perspectivas que se abrem com a inclusão de alguns temas relativos à diversidade cultural e religiosa na sociedade brasileira. Cada dia é perceptível o crescente espaço que o sagrado ocupa na vida cotidiana das pessoas comuns. A presença do sagrado no cotidiano da cultura brasileira é uma marca que realça um relevante aspecto da identidade nacional. A cultura brasileira é uma cultura plural. Para além das matrizes indígenas e européias, existe uma grande variedade cultural no âmbito da africanidade. O presente artigo objetiva analisar como esse elemento sagrado de caráter afro-brasileiro aparece nos enredos das escolas de samba do Rio de Janeiro durante os carnavais de 2011 e 2012. Nosso referencial são as letras dos sambas-enredos das escolas dos grupos C, D, e E que desfilam na Intendente Magalhães, subúrbio do rio de Janeiro. Palavras-chave: Religiosidade. Africana. Sagrado. Carnaval. Rio de Janeiro. Abstract The discussions about the sacred in contemporaneity have gained importance in considering new opportunities opening up with the inclusion of issues related to cultural and religious diversity in Brazilian society. It is noticeable the growing space that sacred plays in everyday life of ordinary people. The presence of the sacred in everyday Brazilian culture is a mark that highlights an relevant aspect of national identity. Brazilian culture is a plural culture. In addition to the indigenous and European origin, there is a great cultural variety in the scope of Africanity. This article aims to analyze how this sacred element of Afro-Brazilian characteristic appears in plots of samba schools in Rio de Janeiro during the carnivals of 2011 and 2012. Our references are the lyrics of the samba schools’ plots of groups C, D, and E, which parade on Intendente Magalhães Street, in a suburban area of Rio de Janeiro. Key

Novel AC Servo Rotating and Linear Composite Driving Device for Plastic Forming Equipment

Science.gov (United States)

Liang, Jin-Tao; Zhao, Sheng-Dun; Li, Yong-Yi; Zhu, Mu-Zhi

2017-07-01

The existing plastic forming equipment are mostly driven by traditional AC motors with long transmission chains, low efficiency, large size, low precision and poor dynamic response are the common disadvantages. In order to realize high performance forming processes, the driving device should be improved, especially for complicated processing motions. Based on electric servo direct drive technology, a novel AC servo rotating and linear composite driving device is proposed, which features implementing both spindle rotation and feed motion without transmission, so that compact structure and precise control can be achieved. Flux switching topology is employed in the rotating drive component for strong robustness, and fractional slot is employed in the linear direct drive component for large force capability. Then the mechanical structure for compositing rotation and linear motion is designed. A device prototype is manufactured, machining of each component and the whole assembly are presented respectively. Commercial servo amplifiers are utilized to construct the control system of the proposed device. To validate the effectiveness of the proposed composite driving device, experimental study on the dynamic test benches are conducted. The results indicate that the output torque can attain to 420 N·m and the dynamic tracking errors are less than about 0.3 rad in the rotating drive. the dynamic tracking errors are less than about 1.6 mm in the linear feed. The proposed research provides a method to construct high efficiency and accuracy direct driving device in plastic forming equipment.

Piloted Simulator Investigation of Techniques to Achieve Attitude Command Response with Limited Authority Servos

National Research Council Canada - National Science Library

Key, David

2002-01-01

The purpose of the study was to develop generic design principles for obtaining attitude command response in moderate to aggressive maneuvers without increasing SCAS series servo authority from the existing +/- 10...

All Digital IQ Servo-System for CERN Linacs

CERN Document Server

Broere, J; Garoby, R; Rohlev, A; Serrano, J

2004-01-01

A VME based control system has been developed and built at CERN for the servo loops regulating the field in linac accelerating structures. It is an all-digital system built on a single VME card, providing digital detection, processing, and modulation. It is foreseen to be used, in different versions, for the needs of both present and future CERN hadron linacs. The first application will be in the energy ramping RF chain of the CERN Heavy Ion Linac (linac 3). Design principle and the experimental results are described.

Dynamic parameter identification of robot arms with servo-controlled electrical motors

Science.gov (United States)

Jiang, Zhao-Hui; Senda, Hiroshi

2005-12-01

This paper addresses the issue of dynamic parameter identification of the robot manipulator with servo-controlled electrical motors. An assumption is made that all kinematical parameters, such as link lengths, are known, and only dynamic parameters containing mass, moment of inertia, and their functions need to be identified. First, we derive dynamics of the robot arm with a linear form of the unknown dynamic parameters by taking dynamic characteristics of the motor and servo unit into consideration. Then, we implement the parameter identification approach to identify the unknown parameters with respect to individual link separately. A pseudo-inverse matrix is used for formulation of the parameter identification. The optimal solution is guaranteed in a sense of least-squares of the mean errors. A Direct Drive (DD) SCARA type industrial robot arm AdeptOne is used as an application example of the parameter identification. Simulations and experiments for both open loop and close loop controls are carried out. Comparison of the results confirms the correctness and usefulness of the parameter identification and the derived dynamic model.

Adaptive control of the radial servo system of a compact disc player

NARCIS (Netherlands)

Draijer, W.; Steinbuch, M.; Bosgra, O.H.

1992-01-01

The radial servo system of a compact disc player has to cope with large gain variations which are due to disc dependent optical characteristics, tolerances in mechanical and electrical components and nonlinearity in the generation of the position index. In current players this problem has been

Use of a novel drainage flow servo-controlled CPB for mitral valve replacement in a Jehovah's Witness.

Science.gov (United States)

Niimi, Yoshinari; Murata, Seiichiro; Mitou, Yumi; Ohno, Yusuke

2018-03-01

We developed a novel open cardiopulmonary bypass (CPB) system, a drainage flow servo-controlled CPB system (DS-CPB), in which rotational speed of the main roller pump is servo-controlled to generate the same amount of flow as the systemic venous drainage. It was designed to safely decrease the priming volume while maintaining a constant reservoir level, even during fluctuations of the drainage flow. We report a successful use of a novel DS-CPB system in an elderly Jehovah's Witness patient with dehydration who underwent mitral valve replacement.

Adaptive-Repetitive Visual-Servo Control of Low-Flying Aerial Robots via Uncalibrated High-Flying Cameras

Science.gov (United States)

Guo, Dejun; Bourne, Joseph R.; Wang, Hesheng; Yim, Woosoon; Leang, Kam K.

2017-08-01

This paper presents the design and implementation of an adaptive-repetitive visual-servo control system for a moving high-flying vehicle (HFV) with an uncalibrated camera to monitor, track, and precisely control the movements of a low-flying vehicle (LFV) or mobile ground robot. Applications of this control strategy include the use of high-flying unmanned aerial vehicles (UAVs) with computer vision for monitoring, controlling, and coordinating the movements of lower altitude agents in areas, for example, where GPS signals may be unreliable or nonexistent. When deployed, a remote operator of the HFV defines the desired trajectory for the LFV in the HFV's camera frame. Due to the circular motion of the HFV, the resulting motion trajectory of the LFV in the image frame can be periodic in time, thus an adaptive-repetitive control system is exploited for regulation and/or trajectory tracking. The adaptive control law is able to handle uncertainties in the camera's intrinsic and extrinsic parameters. The design and stability analysis of the closed-loop control system is presented, where Lyapunov stability is shown. Simulation and experimental results are presented to demonstrate the effectiveness of the method for controlling the movement of a low-flying quadcopter, demonstrating the capabilities of the visual-servo control system for localization (i.e.,, motion capturing) and trajectory tracking control. In fact, results show that the LFV can be commanded to hover in place as well as track a user-defined flower-shaped closed trajectory, while the HFV and camera system circulates above with constant angular velocity. On average, the proposed adaptive-repetitive visual-servo control system reduces the average RMS tracking error by over 77% in the image plane and over 71% in the world frame compared to using just the adaptive visual-servo control law.

Induced hypothermia for infants with hypoxic- ischemic encephalopathy using a servo-controlled fan: an exploratory pilot study.

Science.gov (United States)

Horn, Alan; Thompson, Clare; Woods, David; Nel, Alida; Bekker, Adrie; Rhoda, Natasha; Pieper, Clarissa

2009-06-01

Several trials suggest that hypothermia is beneficial in selected infants with hypoxic-ischemic encephalopathy. However, the cooling methods used required repeated interventions and were either expensive or reported significant temperature variation. The objective of this pilot study was to describe the use, efficacy, and physiologic impact of an inexpensive servo-controlled cooling fan blowing room-temperature air. A servo-controlled fan was manufactured and used to cool 10 infants with hypoxic-ischemic encephalopathy to a rectal temperature of 33 degrees C to 34 degrees C. The infants were sedated with phenobarbital, but clonidine was administered to some infants if shivering or discomfort occurred. A servo-controlled radiant warmer was used simultaneously with the fan to prevent overcooling. The settings used on the fan and radiant warmer differed slightly between some infants as the technique evolved. A rectal temperature of 34 degrees C was achieved in a median time of 58 minutes. Overcooling did not occur, and the mean temperature during cooling was 33.6 degrees C +/- 0.2 degrees C. Inspired oxygen requirements increased in 6 infants, and 5 infants required inotropic support during cooling, but this was progressively reduced after 1 to 2 days. Dehydration did not occur. Five infants shivered when faster fan speeds were used, but 4 of the 5 infants had hypomagnesemia. Shivering was controlled with clonidine in 4 infants, but 1 infant required morphine. Servo-controlled fan cooling with room-temperature air, combined with servo-controlled radiant warming, was an effective, simple, and safe method of inducing and maintaining rectal temperatures of 33 degrees C to 34 degrees C in sedated infants with hypoxic-ischemic encephalopathy. After induction of hypothermia, a low fan speed facilitated accurate temperature control, and warmer-controlled rewarming at 0.2 degrees C increments every 30 minutes resulted in more appropriate rewarming than when 0.5 degrees C

Visual Servo Tracking Control of a Wheeled Mobile Robot with a Monocular Fixed Camera

National Research Council Canada - National Science Library

Chen, J; Dixon, W. E; Dawson, D. M; Chitrakaran, V. K

2004-01-01

In this paper, a visual servo tracking controller for a wheeled mobile robot (WMR) is developed that utilizes feedback from a monocular camera system that is mounted with a fixed position and orientation...

RELIGIÃO E SOCIEDADE PÓS-TRADICIONAL: O CASO DA NEW AGE POPULAR DO VALE DO AMANHECER

Directory of Open Access Journals (Sweden)

Amurabi Pereira de Oliveira

2010-01-01

Full Text Available No contexto da globalização, as formas como os sujeitos experienciam o sagrado modifica-se de tal forma que há um deslocamento da religião para a esfera subjetiva. Numa sociedade pós-tradicional os sistemas peritos (Giddens, 1997 dão respostas e cimentam a confiança do mundo moderno, diante de tal cenário o papel da religião junto à sociedade altera-se, como também sua formulação, o desencaixe entre tempo e espaço permite a reformulação dos elementos do sagrado, práticas locais influenciam práticas globais, assim como de forma inversa, neste sentido emergem práticas originais nas quais os elementos New Agers sofrem uma releitura e são rearticulados com elementos da religiosidade popular no Brasil, o que denominamos New Age Popular, sendo um dos casos mais emblemáticos o Vale do Amanhecer, a partir do qual buscaremos compreender como a composição destas práticas se faz possível neste cenário de transnacionalização do sagrado. Este trabalho parte do estudo etnográfico desenvolvido junto ao templo do Vale do Amanhecer na cidade de Campina Grande, bem como da reflexão teórica realizada em torno das transformações no campo religioso brasileiro.

O Mar da Galileia e seus contextos de simbolismos

Directory of Open Access Journals (Sweden)

Elsbeth Léia Spode Becker

2017-10-01

Full Text Available O artigo descreve o Mar da Galileia e seu entorno no contexto bíblico. Após uma breve apresentação geográfica da região, buscou-se traçar os rumos da história, enfocando, especialmente, o contexto do Cristianismo, evidenciando o ambiente natural dos apóstolos que Jesus convidou para pescar homens e almas. A metodologia está embasada no estado da arte e na perspectiva da pesquisa qualitativa que relaciona a história e a geografia como interação com a experiência no sagrado e a atividade do turismo. Concluiu-se que a história antiga no Mar da Galileia e seu entorno é uma terra de contrastes de religiões e de culturas onde os peregrinos e, também, os turistas buscam a experiência de fé que é visível na geografia e nas ruínas das antigas cidades de Carnafaum, Tiberíades, Magdala, Corazim e Betsaida. O sagrado e o profano coexistem, porém torna-se difícil distinguir os seus limites. O sagrado está nos símbolos que são abrigados pelas igrejas construídas no local para a realização dos ritos de fé. O espaço profano é o entorno, o espaço destinado ao comércio e ao lazer.

Fault detection for discrete-time switched systems with sensor stuck faults and servo inputs.

Science.gov (United States)

Zhong, Guang-Xin; Yang, Guang-Hong

2015-09-01

This paper addresses the fault detection problem of switched systems with servo inputs and sensor stuck faults. The attention is focused on designing a switching law and its associated fault detection filters (FDFs). The proposed switching law uses only the current states of FDFs, which guarantees the residuals are sensitive to the servo inputs with known frequency ranges in faulty cases and robust against them in fault-free case. Thus, the arbitrarily small sensor stuck faults, including outage faults can be detected in finite-frequency domain. The levels of sensitivity and robustness are measured in terms of the finite-frequency H- index and l2-gain. Finally, the switching law and FDFs are obtained by the solution of a convex optimization problem. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Numerical calculation for flow field of servo-tube guided hydraulic control rod driving system

International Nuclear Information System (INIS)

He Keyu; Han Weishi

2010-01-01

A new-style hydraulic control rod driving mechanism was put forward by using servo-tube control elements for the design of control rod driving mechanism. The results of numerical simulation by CFD program Fluent for flow field of hydraulic driving cylinder indicate that the bigger the outer diameter of servo-tube, the smaller the resistance coefficient of variable throttle orifice. The zero position gap of variable throttle orifice could be determined on 0.2 mm in the design. The pressure difference between the upper and nether surfaces of piston was mainly created by the throttle function of fixed throttle orifice. It can be effectively controlled by changing the gap of variable throttle orifice. And the lift force of driving cylinder is able to meet the requirement on the design load. (authors)

Detection of Surface Defects and Servo Signal Restoration for a Compact Disc Player

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

2006-01-01

Compact disc (CD) players have been on the market for more than two decades, and the involved technologies, including control are very mature. Some problems, however, still remain with respect to playing CDs having to surface defects like scratches and fingerprints. Two servo control loops are used...... to keep the optical pick-up unit (OPU) focused and radially locked to the information track of the CD. The problem is to design servo controllers which are well suited for both handling surface defects and disturbances like mechanical shocks. The handling of surface defects requires a low-controller...... bandwidth which is in conflict with the requirement for the handling of disturbances. This control problem can be solved by the use of a fault tolerant control strategy, where the fault detection is very important. The OPU feeds the controllers with detector signals. Based on these, focus and radial...

Servo-controlling structure of five-axis CNC system for real-time NURBS interpolating

Science.gov (United States)

Chen, Liangji; Guo, Guangsong; Li, Huiying

2017-07-01

NURBS (Non-Uniform Rational B-Spline) is widely used in CAD/CAM (Computer-Aided Design / Computer-Aided Manufacturing) to represent sculptured curves or surfaces. In this paper, we develop a 5-axis NURBS real-time interpolator and realize it in our developing CNC(Computer Numerical Control) system. At first, we use two NURBS curves to represent tool-tip and tool-axis path respectively. According to feedrate and Taylor series extension, servo-controlling signals of 5 axes are obtained for each interpolating cycle. Then, generation procedure of NC(Numerical Control) code with the presented method is introduced and the method how to integrate the interpolator into our developing CNC system is given. And also, the servo-controlling structure of the CNC system is introduced. Through the illustration, it has been indicated that the proposed method can enhance the machining accuracy and the spline interpolator is feasible for 5-axis CNC system.

Fuzzy self-learning control for magnetic servo system

Science.gov (United States)

Tarn, J. H.; Kuo, L. T.; Juang, K. Y.; Lin, C. E.

1994-01-01

It is known that an effective control system is the key condition for successful implementation of high-performance magnetic servo systems. Major issues to design such control systems are nonlinearity; unmodeled dynamics, such as secondary effects for copper resistance, stray fields, and saturation; and that disturbance rejection for the load effect reacts directly on the servo system without transmission elements. One typical approach to design control systems under these conditions is a special type of nonlinear feedback called gain scheduling. It accommodates linear regulators whose parameters are changed as a function of operating conditions in a preprogrammed way. In this paper, an on-line learning fuzzy control strategy is proposed. To inherit the wealth of linear control design, the relations between linear feedback and fuzzy logic controllers have been established. The exercise of engineering axioms of linear control design is thus transformed into tuning of appropriate fuzzy parameters. Furthermore, fuzzy logic control brings the domain of candidate control laws from linear into nonlinear, and brings new prospects into design of the local controllers. On the other hand, a self-learning scheme is utilized to automatically tune the fuzzy rule base. It is based on network learning infrastructure; statistical approximation to assign credit; animal learning method to update the reinforcement map with a fast learning rate; and temporal difference predictive scheme to optimize the control laws. Different from supervised and statistical unsupervised learning schemes, the proposed method learns on-line from past experience and information from the process and forms a rule base of an FLC system from randomly assigned initial control rules.

A Novel Rotor and Stator Magnetic Fields Direct-Orthogonalized Vector Control Scheme for the PMSM Servo System

Directory of Open Access Journals (Sweden)

Shi-Xiong Zhang

2014-02-01

Full Text Available Permanent Magnet Synchronous motor (PMSM has received widespread acceptance in recent years. In this paper, a new rotor and stator Magnetic Fields Direct-Orthogonalized Vector Control (MFDOVC scheme is proposed for PMSM servo system. This method simplified the complex calculation of traditional vector control, a part of the system resource is economized. At the same time, through the simulation illustration validation, the performance of PMSM servo system with the proposed MFDOVC scheme can achieve the same with the complex traditional vector control method, but much simpler calculation is implemented using the proposed method.

A port-Hamiltonian approach to image-based visual servo control for dynamic systems

NARCIS (Netherlands)

Mahony, R.; Stramigioli, Stefano

2012-01-01

This paper introduces a port-Hamiltonian framework for the design of image-based visual servo control for dynamic mechanical systems. The approach taken introduces the concept of an image effort and provides an interpretation of energy exchange between the dynamics of the physical system and virtual

Optimization and performance characteristics of servo-piston hydraulic control rod drive mechanism

International Nuclear Information System (INIS)

Yu Mingrui; Han Weishi; Wang Ge

2014-01-01

This paper introduces the structure and working principles of the servo-piston hydraulic control rod drive mechanism (SHCM), which can be moved continuously and has self-lock capacity. The steady state characteristics of SHCM are simulated using FLUENT codes. Based on comparison with the experimental results, the simulation is proven to be credible as a tool to describe the steady state characteristics. Finally, the influence of structural parameters is analyzed to obtain an optimal design. The experimental results indicate that the traction of the servo-tube is larger in the starting and braking stages. The resistance coefficient of SHCM increases gradually in the starting and lifting stage, and then tends to be stable. This coefficient has a maximum value while the inlet pressure is low. Performance norms of SHCM, such as the anti-disturbance ability and positioning accuracy, are tested, the anti-disturbance ability of the actuator is strong while the inlet pressure is fluctuating. The positioning accuracy is high regardless of the action process (lifting or not). (author)

Design of a Novel Servo-motorized Laser Device for Visual Pathways Diseases Therapy

Directory of Open Access Journals (Sweden)

Carlos Ignacio Sarmiento

2015-12-01

Full Text Available We discuss a novel servo-motorized laser device and a research protocol for visual pathways diseases therapies. The proposed servo-mechanized laser device can be used for potential rehabilitation of patients with hemianopia, quadrantanopia, scotoma, and some types of cortical damages. The device uses a semi spherical structure where the visual stimulus will be shown inside, according to a previous stimuli therapy designed by an ophthalmologist or neurologist. The device uses a pair of servomotors (with torque=1.5kg, which controls the laser stimuli position for the internal therapy and another pair for external therapy. Using electronic tools such as microcontrollers along with miscellaneous electronic materials, combined with LabVIEW based interface, a control mechanism is developed for the new device. The proposed device is well suited to run various visual stimuli therapies. We outline the major design principles including the physical dimensions, laser device’s kinematical analysis and the corresponding software development.

Turbofan Volume Dynamics Model for Investigations of Aero-Propulso-Servo-Elastic Effects in a Supersonic Commercial Transport

Science.gov (United States)

Connolly, Joseph W.; Kopasakis, George; Lemon, Kimberly A.

2010-01-01

A turbofan simulation has been developed for use in aero-propulso-servo-elastic coupling studies, on supersonic vehicles. A one-dimensional lumped volume approach is used whereby each component (fan, high-pressure compressor, combustor, etc.) is represented as a single volume using characteristic performance maps and conservation equations for continuity, momentum and energy. The simulation is developed in the MATLAB/SIMULINK (The MathWorks, Inc.) environment in order to facilitate controls development, and ease of integration with a future aero-servo-elastic vehicle model being developed at NASA Langley. The complete simulation demonstrated steady state results that closely match a proposed engine suitable for a supersonic business jet at the cruise condition. Preliminary investigation of the transient simulation revealed expected trends for fuel flow disturbances as well as upstream pressure disturbances. A framework for system identification enables development of linear models for controller design. Utilizing this framework, a transfer function modeling an upstream pressure disturbance s impacts on the engine speed is developed as an illustrative case of the system identification. This work will eventually enable an overall vehicle aero-propulso-servo-elastic model

Exploiting H infinity sampled-data control theory for high-precision electromechanical servo control design

NARCIS (Netherlands)

Oomen, T.A.E.; Wal, van de M.M.J.; Bosgra, O.H.

2006-01-01

Optimal design of digital controllers for industrial electromechanical servo systems using an Hinf-criterion is considered. Present industrial practice is to perform the control design in the continuous time domain and to discretize the controller a posteriori. This procedure involves unnecessary

Servo-control for maintaining abdominal skin temperature at 36C in low birth weight infants.

Science.gov (United States)

Sinclair, J C

2002-01-01

Randomized trials have shown that the neonatal mortality rate of low birth-weight babies can be reduced by keeping them warm. For low birth-weight babies nursed in incubators, warm conditions may be achieved either by heating the air to a desired temperature, or by servo-controlling the baby's body temperature at a desired set-point. In low birth weight infants, to determine the effect on death and other important clinical outcomes of targeting body temperature rather than air temperature as the end-point of control of incubator heating. Standard search strategy of the Cochrane Neonatal Review Group. Searches were made of the Cochrane Controlled Trials Register (CCTR) (Cochrane Library, Issue 4, 2001) and MEDLINE, 1966 to November 2001. Randomized or quasi-randomized trials which test the effects of having the heat output of the incubator servo-controlled from body temperature compared with setting a constant incubator air temperature. Trial methodologic quality was systematically assessed. Outcome measures included death, timing of death, cause of death, and other clinical outcomes. Categorical outcomes were analyzed using relative risk and risk difference. Meta-analysis assumed a fixed effect model. Two eligible trials were found. In total, they included 283 babies and 112 deaths. Compared to setting a constant incubator air temperature of 31.8C, servo-control of abdominal skin temperature at 36C reduces the neonatal death rate among low birth weight infants: relative risk 0.72 (95% CI 0.54, 0.97); risk difference -12.7% (95% CI -1.6, -23.9). This effect is even greater among VLBW infants. During at least the first week after birth, low birth weight babies should be provided with a carefully regulated thermal environment that is near the thermoneutral point. For LBW babies in incubators, this can be achieved by adjusting incubator temperature to maintain an anterior abdominal skin temperature of at least 36C, using either servo-control or frequent manual

Development of X-Y servo pneumatic-piezoelectric hybrid actuators for position control with high response, large stroke and nanometer accuracy.

Science.gov (United States)

Chiang, Mao-Hsiung

2010-01-01

This study aims to develop a X-Y dual-axial intelligent servo pneumatic-piezoelectric hybrid actuator for position control with high response, large stroke (250 mm, 200 mm) and nanometer accuracy (20 nm). In each axis, the rodless pneumatic actuator serves to position in coarse stroke and the piezoelectric actuator compensates in fine stroke. Thus, the overall control systems of the single axis become a dual-input single-output (DISO) system. Although the rodless pneumatic actuator has relatively larger friction force, it has the advantage of mechanism for multi-axial development. Thus, the X-Y dual-axial positioning system is developed based on the servo pneumatic-piezoelectric hybrid actuator. In addition, the decoupling self-organizing fuzzy sliding mode control is developed as the intelligent control strategies. Finally, the proposed novel intelligent X-Y dual-axial servo pneumatic-piezoelectric hybrid actuators are implemented and verified experimentally.

Development of X-Y Servo Pneumatic-Piezoelectric Hybrid Actuators for Position Control with High Response, Large Stroke and Nanometer Accuracy

Directory of Open Access Journals (Sweden)

Mao-Hsiung Chiang

2010-03-01

Full Text Available This study aims to develop a X-Y dual-axial intelligent servo pneumatic-piezoelectric hybrid actuator for position control with high response, large stroke (250 mm, 200 mm and nanometer accuracy (20 nm. In each axis, the rodless pneumatic actuator serves to position in coarse stroke and the piezoelectric actuator compensates in fine stroke. Thus, the overall control systems of the single axis become a dual-input single-output (DISO system. Although the rodless pneumatic actuator has relatively larger friction force, it has the advantage of mechanism for multi-axial development. Thus, the X-Y dual-axial positioning system is developed based on the servo pneumatic-piezoelectric hybrid actuator. In addition, the decoupling self-organizing fuzzy sliding mode control is developed as the intelligent control strategies. Finally, the proposed novel intelligent X-Y dual-axial servo pneumatic-piezoelectric hybrid actuators are implemented and verified experimentally.

Analysis of and H∞ Controller Design For An Electro-Hydraulic Servo Pressure Regulator

DEFF Research Database (Denmark)

Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole

2011-01-01

-circuit pumps are still hydraulically controlled, there is however still a need for being able to generate a hydraulic pilot pressure. The focus of the current paper is on the analysis and controller design of an electrohydraulic servo pressure regulator, which generates a hydraulic LS-pressure for a variable...

Image-Based Visual Servoing for Manipulation Via Predictive Control – A Survey of Some Results

Directory of Open Access Journals (Sweden)

Corneliu Lazăr

2016-09-01

Full Text Available In this paper, a review of predictive control algorithms developed by the authors for visual servoing of robots in manipulation applications is presented. Using these algorithms, a control predictive framework was created for image-based visual servoing (IBVS systems. Firstly, considering the point features, in the year 2008 we introduced an internal model predictor based on the interaction matrix. Secondly, distinctly from the set-point trajectory, we introduced in 2011 the reference trajectory using the concept from predictive control. Finally, minimizing a sum of squares of predicted errors, the optimal input trajectory was obtained. The new concept of predictive control for IBVS systems was employed to develop a cascade structure for motion control of robot arms. Simulation results obtained with a simulator for predictive IBVS systems are also presented.

The computer-aided design of a servo system as a multiple-criteria decision problem

NARCIS (Netherlands)

Udink ten Cate, A.J.

1986-01-01

This paper treats the selection of controller gains of a servo system as a multiple-criteria decision problem. In contrast to the usual optimization-based approaches to computer-aided design, inequality constraints are included in the problem as unconstrained objectives. This considerably simplifies

Evaluation of Linear and Non-Linear Control Schemes Applied to a Hydraulic Servo System

DEFF Research Database (Denmark)

Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik Clemmensen

2005-01-01

Due to the innovation of low-cost electronics such as sensors, microcontrollers etc., the focus on highperformance motion control is increasing. This work focuses on position control of single-input single-output hydraulic servo-systems in general. A hydraulically actuated robotic manipulator...

Optimality based repetitive controller design for track-following servo system of optical disk drives.

Science.gov (United States)

Chen, Wentao; Zhang, Weidong

2009-10-01

In an optical disk drive servo system, to attenuate the external periodic disturbances induced by inevitable disk eccentricity, repetitive control has been used successfully. The performance of a repetitive controller greatly depends on the bandwidth of the low-pass filter included in the repetitive controller. However, owing to the plant uncertainty and system stability, it is difficult to maximize the bandwidth of the low-pass filter. In this paper, we propose an optimality based repetitive controller design method for the track-following servo system with norm-bounded uncertainties. By embedding a lead compensator in the repetitive controller, both the system gain at periodic signal's harmonics and the bandwidth of the low-pass filter are greatly increased. The optimal values of the repetitive controller's parameters are obtained by solving two optimization problems. Simulation and experimental results are provided to illustrate the effectiveness of the proposed method.

Experimental consideration for realizing image based visual servo control system

International Nuclear Information System (INIS)

Ishikawa, N.; Suzuki, K.; Fujii, Y.; Usui, H.

1995-01-01

In this study, we consider the experimental aspect of image based visual servo control system. The items considered are the following; 1) Inertial parameter estimation, 2) Focal point estimation, 3) Controller performance for the system with delay. From the experimental result of visual control, it is found that the system is very sensitive to the controller gain because of the computational delay of vision. In order to establish a satisfactory delay compensation, more investigations on controller design are required. (author)

A Quasiphysics Intelligent Model for a Long Range Fast Tool Servo

Science.gov (United States)

Liu, Qiang; Zhou, Xiaoqin; Lin, Jieqiong; Xu, Pengzi; Zhu, Zhiwei

2013-01-01

Accurately modeling the dynamic behaviors of fast tool servo (FTS) is one of the key issues in the ultraprecision positioning of the cutting tool. Herein, a quasiphysics intelligent model (QPIM) integrating a linear physics model (LPM) and a radial basis function (RBF) based neural model (NM) is developed to accurately describe the dynamic behaviors of a voice coil motor (VCM) actuated long range fast tool servo (LFTS). To identify the parameters of the LPM, a novel Opposition-based Self-adaptive Replacement Differential Evolution (OSaRDE) algorithm is proposed which has been proved to have a faster convergence mechanism without compromising with the quality of solution and outperform than similar evolution algorithms taken for consideration. The modeling errors of the LPM and the QPIM are investigated by experiments. The modeling error of the LPM presents an obvious trend component which is about ±1.15% of the full span range verifying the efficiency of the proposed OSaRDE algorithm for system identification. As for the QPIM, the trend component in the residual error of LPM can be well suppressed, and the error of the QPIM maintains noise level. All the results verify the efficiency and superiority of the proposed modeling and identification approaches. PMID:24163627

Dynamic Response of Control Servo System Installed in NAES-Equipped SB2C-5 Airplane (BuAer No. 83135)

Science.gov (United States)

Smaus, Louis H.; Stewart, Elwood C.

1950-01-01

Dynamic--response measurements for various conditions of displacement and rate signal input, sensitivity setting, and simulated hinge moment were made of the three control-surface servo systems of an NAES-equipped remote-controlled airplane while on the ground. The basic components of the servo systems are those of the General Electric Company type G-1 autopilot using electrical signal. sources, solenoid-operated valves, and hydraulic pistons. The test procedures and difficulties are discussed, Both frequency and transient-response data, are presented and comparisons are made. The constants describing the servo system, the undamped natural frequency, and the damping ratio, are determined by several methods. The response of the system with the addition of airframe rate signal is calculated. The transfer function of the elevator surface, linkage, and cable system is obtained. The agreement between various methods of measurement and calculation is considered very good. The data are complete enough and in such form that they may be used directly with the frequency-response data of an airplane to predict the stability of the autopilot-airplane combination.

A new approach to control of xenon spatial oscillation during load follow operation via robust servo systems

International Nuclear Information System (INIS)

Ukai, Hiroyuki; Iwazumi, Tetsuo

1994-01-01

The control problem of xenon-induced spatial oscillations of PWR in the axial direction during a load following operation is investigated. The system models are described by a one-group diffusion equation with xenon and temperature feed-backs, iodine and xenon dynamic equations, and heat conductions processes. Control is implemented by the full-length and the part-length control rods and the boron concentration. In order to achieve the control purpose, control models are formulated as the design problem of robust servo systems for distributed parameter reactor systems. The total thermal power and the axial offset are chosen as outputs to be controlled. The control systems consist of servo compensators and stabilizing compensators. They are designed based on the finite-dimensional systems which are constructed by linearizing around steady states, approximately by the Galerkin method, and reducing dimensions via the singular perturbation method. A new and simple computational algorithm to obtain an approximate solution of a steady-state neutron balance is developed via the perturbation method. Some results of numerical simulations are shown in order to discuss the effectiveness of the theory developed in this paper. In particular, it is shown that the designed servo systems are robust against model errors with linearization and modal truncation

A Port-Hamiltonian Approach to Visual Servo Control of a Pick and Place System

NARCIS (Netherlands)

Dirksz, Daniel A.; Scherpen, Jacquelien M. A.; Steinbuch, Maarten

In this paper, we take a port-Hamiltonian approach to address the problem of image-based visual servo control of a pick and place system. Through a coordinate transformation and a passive interconnection between mechanical system and camera dynamics we realize a closed-loop system that is

Influence of Forming Conditions on Springback in V-bending Process Using Servo Press

Science.gov (United States)

Abe, Shinya; Takahashi, Susumu

To improve fuel efficiency, aluminum alloys and high tensile steel sheets are increasingly being applied to automotive body parts. However, it is difficult to obtain accurate dimensions of formed parts. Therefore, technologies for reducing springback for the part formed by press are strongly demanded. It is said that the die holding time at the bottom dead center of a servo press slide can affect springback. To clarify the forming mechanisms of this phenomenon, a V bending test with a servo press was performed. Aluminum alloys sheets are applied as specimens. The location of press slide was measured by linear scales. It was found that the movement of the slide in a slide motion program differs from the actual movement of the slide. It is important to confirm if the slide is located in the position specified in the program. In addition, a springback angle measurement system is proposed that uses laser displacement measurement apparatus. Because it avoids human error, the proposed measurement system is more accurate than the image processing method.

SYNTHESIS OF THE SERVO DRIVER WITH SPEED LOOP TUNED AT THE MODULAR OPTIMUM

Directory of Open Access Journals (Sweden)

Mr. Sergei V. Stelmashchuk

2016-12-01

Full Text Available The paper presents a method of synthesis of servo driver for controlling the speed of the object with the speed tuned at the modular optimum. An automatic electric motor drive is considered as the controlled element. This assumes the use of the speed sensor on the output shaft of the drive gear. This approach can be used for geared motors, which are more commonly used in a variety of compact drives. The technique is based on the method of synthesis by using logarithmic frequency response (LFR. The result is a synthesis of the two tracking angle controllers: proportional-integral and proportional-derivative (PIPD regulator. The criterion for the synthesis of tracking angle controller is the desired LFR, the characteristics of which are defined based on saturated capability transition function of controlled object with standard configuration for modular optimum. It is assumed that the maximum speed and acceleration of the transition functions are required for the synthesis of parameters of servo driver system by LFR. The article covers the accuracy and contains an example of a particular electric motor.

Adaptive servo ventilation for central sleep apnoea in heart failure : SERVE-HF on-treatment analysis

NARCIS (Netherlands)

Woehrle, Holger; Cowie, Martin R.; Eulenburg, Christine; Suling, Anna; Angermann, Christiane; d'Ortho, Marie-Pia; Erdmann, Erland; Levy, Patrick; Simonds, Anita K.; Somers, Virend K.; Zannad, Faiez; Teschler, Helmut; Wegscheider, Karl

2017-01-01

This on-treatment analysis was conducted to facilitate understanding of mechanisms underlying the increased risk of all-cause and cardiovascular mortality in heart failure patients with reduced ejection fraction and predominant central sleep apnoea randomised to adaptive servo ventilation versus the

A port-Hamiltonian approach to visual servo control of a pick and place system

NARCIS (Netherlands)

Dirksz, Daniel A.; Scherpen, Jacquelien M.A.

2012-01-01

In this paper we take a port-Hamiltonian approach to address the problem of image-based visual servo control of a pick and place system. We realize a closed-loop system, including the nonlinear camera dynamics, which is port-Hamiltonian. Although the closed-loop system is nonlinear, the resulting

A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads

Directory of Open Access Journals (Sweden)

Hao-Ting Lin

2017-06-01

Full Text Available This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

A Novel Real-Time Path Servo Control of a Hardware-in-the-Loop for a Large-Stroke Asymmetric Rod-Less Pneumatic System under Variable Loads.

Science.gov (United States)

Lin, Hao-Ting

2017-06-04

This project aims to develop a novel large stroke asymmetric pneumatic servo system of a hardware-in-the-loop for path tracking control under variable loads based on the MATLAB Simulink real-time system. High pressure compressed air provided by the air compressor is utilized for the pneumatic proportional servo valve to drive the large stroke asymmetric rod-less pneumatic actuator. Due to the pressure differences between two chambers, the pneumatic actuator will operate. The highly nonlinear mathematical models of the large stroke asymmetric pneumatic system were analyzed and developed. The functional approximation technique based on the sliding mode controller (FASC) is developed as a controller to solve the uncertain time-varying nonlinear system. The MATLAB Simulink real-time system was a main control unit of a hardware-in-the-loop system proposed to establish driver blocks for analog and digital I/O, a linear encoder, a CPU and a large stroke asymmetric pneumatic rod-less system. By the position sensor, the position signals of the cylinder will be measured immediately. The measured signals will be viewed as the feedback signals of the pneumatic servo system for the study of real-time positioning control and path tracking control. Finally, real-time control of a large stroke asymmetric pneumatic servo system with measuring system, a large stroke asymmetric pneumatic servo system, data acquisition system and the control strategy software will be implemented. Thus, upgrading the high position precision and the trajectory tracking performance of the large stroke asymmetric pneumatic servo system will be realized to promote the high position precision and path tracking capability. Experimental results show that fifth order paths in various strokes and the sine wave path are successfully implemented in the test rig. Also, results of variable loads under the different angle were implemented experimentally.

Numerical calculation of three-dimensional flow field of servo-piston hydraulic control rod driving mechanism

International Nuclear Information System (INIS)

Yu Mingrui; Han Weishi; Wang Ge

2014-01-01

Servo-piston hydraulic control rod driving mechanism is a new type built-in driving mechanism which is suitable for integrated reactor and it can be moved continuously. The numerical calculation and analysis of the internal three-dimensional flow field inside the driving mechanism were carried out by the computational fluid dynamics software FLUENT. The result shows that the unique pressure mutation area of flow field inside the driving mechanism is at the place of the servo variable throttle orifice. The differential pressure of the piston can be effectively controlled by changing the gap of variable throttle orifice. When the gap changes within 0.5 mm, the differential pressure can be greatly changed, and then the driving mechanism motion state would be changed too. When the working pressure is 0.1 MPa, the hoisting capacity of the driving mechanism can meet the design requirements, and the flow rate is small. (authors)

The analysis and compensation of errors of precise simple harmonic motion control under high speed and large load conditions based on servo electric cylinder

Science.gov (United States)

Ma, Chen-xi; Ding, Guo-qing

2017-10-01

Simple harmonic waves and synthesized simple harmonic waves are widely used in the test of instruments. However, because of the errors caused by clearance of gear and time-delay error of FPGA, it is difficult to control servo electric cylinder in precise simple harmonic motion under high speed, high frequency and large load conditions. To solve the problem, a method of error compensation is proposed in this paper. In the method, a displacement sensor is fitted on the piston rod of the electric cylinder. By using the displacement sensor, the real-time displacement of the piston rod is obtained and fed back to the input of servo motor, then a closed loop control is realized. There is compensation of pulses in the next period of the synthetic waves. This paper uses FPGA as the processing core. The software mainly comprises a waveform generator, an Ethernet module, a memory module, a pulse generator, a pulse selector, a protection module, an error compensation module. A durability of shock absorbers is used as the testing platform. The durability mainly comprises a single electric cylinder, a servo motor for driving the electric cylinder, and the servo motor driver.

Fault Detection and Severity Analysis of Servo Valves Using Recurrence Quantification Analysis

Science.gov (United States)

2014-10-02

method of false nearest neighbors, we found that the minimum embedding dimension for the system is d=2. Figure 3 shows the recurrence plots of the...manufacturing process planning method for the components of a complex mechatronic system . Applied Mathematical Modelling, 37(24), 9829–9845. Samadani, M...diagnostics of nonlinear systems . A detailed nonlinear math- ematical model of a servo electro-hydraulic system has been used to demonstrate the procedure

New mode switching algorithm for the JPL 70-meter antenna servo controller

Science.gov (United States)

Nickerson, J. A.

1988-01-01

The design of control mode switching algorithms and logic for JPL's 70 m antenna servo controller are described. The old control mode switching logic was reviewed and perturbation problems were identified. Design approaches for mode switching are presented and the final design is described. Simulations used to compare old and new mode switching algorithms and logic show that the new mode switching techniques will significantly reduce perturbation problems.

Bi-level positive pressure ventilation and adaptive servo ventilation in patients with heart failure and Cheyne-Stokes respiration.

Science.gov (United States)

Fietze, Ingo; Blau, Alexander; Glos, Martin; Theres, Heinz; Baumann, Gert; Penzel, Thomas

2008-08-01

Nocturnal positive pressure ventilation (PPV) has been shown to be effective in patients with impaired left ventricular ejection fraction (LVEF) and Cheyne-Stokes respiration (CSR). We investigated the effect of a bi-level PPV and adaptive servo ventilation on LVEF, CSR, and quantitative sleep quality. Thirty-seven patients (New York heart association [NYHA] II-III) with LVEFCSR were investigated by electrocardiography (ECG), echocardiography and polysomnography. The CSR index (CSRI) was 32.3+/-16.2/h. Patients were randomly treated with bi-level PPV using the standard spontaneous/timed (S/T) mode or with adaptive servo ventilation mode (AutoSetCS). After 6 weeks, 30 patients underwent control investigations with ECG, echocardiography, and polysomnography. The CSRI decreased significantly to 13.6+/-13.4/h. LVEF increased significantly after 6 weeks of ventilation (from 25.1+/-8.5 to 28.8+/-9.8%, plevel PPV and adaptive servo ventilation: the CSRI decreased more in the AutoSetCS group while the LVEF increased more in the bi-level PPV group. Administration of PPV can successfully attenuate CSA. Reduced CSA may be associated with improved LVEF; however, this may depend on the mode of PPV. Changed LVEF is evident even in the absence of significant changes in blood pressure.

A Study on the Air Vent Valve of the Hydraulic Servo Actuator for Steam Control of Power Plants

International Nuclear Information System (INIS)

Lee, Yong Bum; Lee, Jong Jik

2016-01-01

To produce adequate electricity in nuclear and thermal power plants, an optimal amount of steam should be supplied to a generator connected to high- and low-pressure steam turbines. A turbine output control device, which is a special steam valve employed to supply or interrupt the steam to the turbine, is operated using a hydraulic servo actuator. In power plants, the performance of servo actuators is degraded by the air generated from the hydraulic system, or causes frequent failures owing to an increase in the wear of the seal. This is due to the seal being burnt as generated heat using the produced compressed air. Some power plants have exhausted air using a fixed orifice, and thus they encounter power loss due to mass flow exhaust. Failures are generated in hydraulic pumps, electric motors, and valves, which are frequently operated. In this study, we perform modeling and analysis of the load-sensing air-exhaust valves, which can be passed through very fine flow under normal use conditions, and exhaust mass flow air at the beginning stage as with existing fixed orifices. Then, we propose a method to prevent failures due to the compressed air, and to ensure the control accuracy of hydraulic servo actuators.

A Study on the Air Vent Valve of the Hydraulic Servo Actuator for Steam Control of Power Plants

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Bum; Lee, Jong Jik [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

2016-06-15

To produce adequate electricity in nuclear and thermal power plants, an optimal amount of steam should be supplied to a generator connected to high- and low-pressure steam turbines. A turbine output control device, which is a special steam valve employed to supply or interrupt the steam to the turbine, is operated using a hydraulic servo actuator. In power plants, the performance of servo actuators is degraded by the air generated from the hydraulic system, or causes frequent failures owing to an increase in the wear of the seal. This is due to the seal being burnt as generated heat using the produced compressed air. Some power plants have exhausted air using a fixed orifice, and thus they encounter power loss due to mass flow exhaust. Failures are generated in hydraulic pumps, electric motors, and valves, which are frequently operated. In this study, we perform modeling and analysis of the load-sensing air-exhaust valves, which can be passed through very fine flow under normal use conditions, and exhaust mass flow air at the beginning stage as with existing fixed orifices. Then, we propose a method to prevent failures due to the compressed air, and to ensure the control accuracy of hydraulic servo actuators.

Robust control for a biaxial servo with time delay system based on adaptive tuning technique.

Science.gov (United States)

Chen, Tien-Chi; Yu, Chih-Hsien

2009-07-01

A robust control method for synchronizing a biaxial servo system motion is proposed in this paper. A new network based cross-coupled control and adaptive tuning techniques are used together to cancel out the skew error. The conventional fixed gain PID cross-coupled controller (CCC) is replaced with the adaptive cross-coupled controller (ACCC) in the proposed control scheme to maintain biaxial servo system synchronization motion. Adaptive-tuning PID (APID) position and velocity controllers provide the necessary control actions to maintain synchronization while following a variable command trajectory. A delay-time compensator (DTC) with an adaptive controller was augmented to set the time delay element, effectively moving it outside the closed loop, enhancing the stability of the robust controlled system. This scheme provides strong robustness with respect to uncertain dynamics and disturbances. The simulation and experimental results reveal that the proposed control structure adapts to a wide range of operating conditions and provides promising results under parameter variations and load changes.

Digital simulation of FM-ZCS-quasi resonant converter fed DD servo drive using Matlab Simulink

Directory of Open Access Journals (Sweden)

Kattamuri Narasimha Rao

2009-01-01

Full Text Available This paper deals with digital simulation of FM-ZCS-quasi resonant converter fed DC servo drive using Matlab Simulink. Quasi Resonant Converter (QRC is fast replacing conventional PWM converters in high frequency operation. The salient feature of QRC is that the switching devices can be either switched on at zero voltage or switched off at zero current, so that switching losses are zero ideally. Switching stresses are low, volumes are low and power density is high. This property imparts high efficiency and high power density to the converters. The output of QRC is regulated by varying the switching frequency of the converter. Hence it is called Frequency modulated Zero current/zero voltage switching quasi resonant converter. The present work deals with simulation of DC Servo motor fed from ZCS-QRC using Matlab. Simulation results show that the ZCS-QRC's have low total harmonic distortion. The ZCS-QRC operating in half wave and full wave modes are simulated successfully. .

Modeling and Parameter Identification of the Vibration Characteristics of Armature Assembly in a Torque Motor of Hydraulic Servo Valves under Electromagnetic Excitations

Directory of Open Access Journals (Sweden)

Jinghui Peng

2014-07-01

Full Text Available The resonance of the armature assembly is the main problem leading to the fatigue of the spring pipe in a torque motor of hydraulic servo valves, which can cause the failure of servo valves. To predict the vibration characteristics of the armature assembly, this paper focuses on the mathematical modeling of the vibration characteristics of armature assembly in a hydraulic servo valve and the identification of parameters in the models. To build models more accurately, the effect of the magnetic spring is taken into account. Vibration modal analysis is performed to obtain the mode shapes and natural frequencies, which are necessary to implement the identification of damping ratios in the mathematical models. Based on the mathematical models for the vibration characteristics, the harmonic responses of the armature assembly are analyzed using the finite element method and measured under electromagnetic excitations. The simulation results agree well with the experimental studies.

Measuring the photodetector frequency response for ultrasonic applications by a heterodyne system with difference- frequency servo control.

Science.gov (United States)

Koch, Christian

2010-05-01

A technique for the calibration of photodiodes in ultrasonic measurement systems using standard and cost-effective optical and electronic components is presented. A heterodyne system was realized using two commercially available distributed feedback lasers, and the required frequency stability and resolution were ensured by a difference-frequency servo control scheme. The frequency-sensitive element generating the error signal for the servo loop comprised a delay-line discriminator constructed from electronic elements. Measurements were carried out at up to 450 MHz, and the uncertainties of about 5% (k = 2) can be further reduced by improved radio frequency power measurement without losing the feature of using only simple elements. The technique initially dedicated to the determination of the frequency response of photodetectors applied in ultrasonic applications can be transferred to other application fields of optical measurements.

Experimental study on performance characteristics of servo-piston hydraulic control rod driving mechanism

International Nuclear Information System (INIS)

Yu Mingrui; Han Weishi; Zhou Jie; Liu Chunyu; Yang Zhida; Wang Ge

2014-01-01

An experimental study on the performance characteristics of the servo-piston hydraulic control rod driving mechanism is carried out, the dynamic processes of the driving mechanism are obtained through the experiments in different working conditions. Combined with the structure characteristics of the driving mechanism, the change rule between the characteristics parameters and the working condition is analyzed. The results indicate that the traction of the servo-tube decreases quickly at first, then slowly and finally trends to be a constant with the working pressure increasing, the tractions are the largest in the startup and deboost phases. The under pressure of the drive cylinder rises slowly and the upper pressure decreases rapidly at the beginning of the rise, the variation trend is opposite in the falling stage. There exists quick and clear flow change processes in the startup and deboost phases, the flow mutation value reduces and the mutation time changes a little with the working pressure increasing. The driving mechanism runs stable and has high sensitivity precision, the load does not vibrate at all when working conditions has small disturbance, a steady transform can be realized among every condition. (authors)

Finite-time tracking control for multiple non-holonomic mobile robots based on visual servoing

Science.gov (United States)

Ou, Meiying; Li, Shihua; Wang, Chaoli

2013-12-01

This paper investigates finite-time tracking control problem of multiple non-holonomic mobile robots via visual servoing. It is assumed that the pinhole camera is fixed to the ceiling, and camera parameters are unknown. The desired reference trajectory is represented by a virtual leader whose states are available to only a subset of the followers, and the followers have only interaction. First, the camera-objective visual kinematic model is introduced by utilising the pinhole camera model for each mobile robot. Second, a unified tracking error system between camera-objective visual servoing model and desired reference trajectory is introduced. Third, based on the neighbour rule and by using finite-time control method, continuous distributed cooperative finite-time tracking control laws are designed for each mobile robot with unknown camera parameters, where the communication topology among the multiple mobile robots is assumed to be a directed graph. Rigorous proof shows that the group of mobile robots converges to the desired reference trajectory in finite time. Simulation example illustrates the effectiveness of our method.

Antenna servo control system characterization: Rate loop analysis for 34-m antenna at DSS 15

Science.gov (United States)

Nickerson, J. A.; Cox, D. G.; Smith, H. K.; Engel, J. H.; Ahlstrom, H. G.

1986-01-01

The elevation and azimuth servo rate loops at the 34-m High Efficiency Deep Space Station 15 (DSS 15) are described. Time and frequency response performance criteria were measured. The results are compared to theoretically deduced performance criteria. Unexpected anomalies in the frequency response are observed and identified.

El aprendizaje significativo en los estudiantes de noveno de básica en el año lectivo 2014 – 2015 de la Unidad Educativa “Sagrado Corazón de Jesús” del cantón Latacunga

OpenAIRE

Osorio Proaño, Laura Graciela

2015-01-01

La Unidad Educativa “Sagrado Corazón de Jesús” dirigida por la comunidad Betlemita, ofrece un servicio educativo dentro de la provincia de Cotopaxi. Frente a la problemática de los resultados de las evaluaciones internas y externas de las estudiantes de Educación Básica en las cuatro áreas elementales (Matemática, Estudios Sociales, Ciencias Naturales, Lengua y Literatura), se analizó la coherencia entre algunos elementos de la propuesta de la Reforma Curricular y el aprendizaje significativo...

Development of the maintenance process by the servo manipulator for the parts of the equipment outside the MSM's workspace in a hot cell

International Nuclear Information System (INIS)

Lee, J. Y.; Kim, S. H.; Song, D. K.; Park, B. S.; Yun, G. S.

2003-01-01

In this study, the maintenance process by the servo manipulator for the parts of the equipment that cannot be reached by MSM in the hot cell was developed. To do this, the virtual mock up is implemented using virtual prototyping technology. And, Using this mock-up, the workspace of the manipulators in the hot cell and the operator's view through the wall-mounted lead glass are analyzed. And the path planning of the servo manipulator using the collision detection of the virtual mockup is established. Also, the maintenance process for the parts of the equipment that are located out area of the MSM's workspace by the servo manipulator is proposed and verified through the graphic simulation. The proposed remote maintenance process of the equipment can be effectively used in the real hot cell operation. Also, the implemented virtual mock-up of the hot cell can be effecively used in analyzing the various hot cell operation and in enhancing the reliability and safety of the spent fuel manaement

Servo-driven piezo common rail diesel injection system; Servogetriebene Piezo-Common-Rail-Dieseleinspritzung

Energy Technology Data Exchange (ETDEWEB)

Schoeppe, Detlev; Stahl, Christian; Krueger, Grit; Dian, Vincent [Continental Automotive GmbH, Regensburg (Germany). Geschaeftsbereich Engine Systems

2012-03-15

The requirements to be met by future diesel engines represent major challenges for fuel injection technology: Fuel consumption, emissions and noise development are to be further reduced without impairing driving enjoyment. To address these challenges, Continental has developed a new fuel injection system that features a high level of precision and accuracy. The key component is a servo-driven injector that is operated in a closed control circuit. (orig.)

Forward Models Applied in Visual Servoing for a Reaching Task in the iCub Humanoid Robot

Directory of Open Access Journals (Sweden)

Daniel Fernando Tello Gamarra

2009-01-01

Full Text Available This paper details the application of a forward model to improve a reaching task. The reaching task must be accomplished by a humanoid robot with 53 degrees of freedom (d.o.f. and a stereo-vision system. We have explored via simulations a new way of constructing and utilizing a forward model that encodes eye–hand relationships. We constructed a forward model using the data obtained from only a single reaching attempt. ANFIS neural networks are used to construct the forward model, but the forward model is updated online with new information that comes from each reaching attempt. Using the obtained forward model, an initial image Jacobian is estimated and is used with a visual servoing controller. Simulation results demonstrate that errors are lower when the initial image Jacobian is derived from the forward model. This paper is one of the few attempts at applying visual servoing in a complete humanoid robot.

iSERVO: Implementing the International Solid Earth Research Virtual Observatory by Integrating Computational Grid and Geographical Information Web Services

Science.gov (United States)

Aktas, Mehmet; Aydin, Galip; Donnellan, Andrea; Fox, Geoffrey; Granat, Robert; Grant, Lisa; Lyzenga, Greg; McLeod, Dennis; Pallickara, Shrideep; Parker, Jay; Pierce, Marlon; Rundle, John; Sayar, Ahmet; Tullis, Terry

2006-12-01

We describe the goals and initial implementation of the International Solid Earth Virtual Observatory (iSERVO). This system is built using a Web Services approach to Grid computing infrastructure and is accessed via a component-based Web portal user interface. We describe our implementations of services used by this system, including Geographical Information System (GIS)-based data grid services for accessing remote data repositories and job management services for controlling multiple execution steps. iSERVO is an example of a larger trend to build globally scalable scientific computing infrastructures using the Service Oriented Architecture approach. Adoption of this approach raises a number of research challenges in millisecond-latency message systems suitable for internet-enabled scientific applications. We review our research in these areas.

Visual Servoing for an Autonomous Hexarotor Using a Neural Network Based PID Controller.

Science.gov (United States)

Lopez-Franco, Carlos; Gomez-Avila, Javier; Alanis, Alma Y; Arana-Daniel, Nancy; Villaseñor, Carlos

2017-08-12

In recent years, unmanned aerial vehicles (UAVs) have gained significant attention. However, we face two major drawbacks when working with UAVs: high nonlinearities and unknown position in 3D space since it is not provided with on-board sensors that can measure its position with respect to a global coordinate system. In this paper, we present a real-time implementation of a servo control, integrating vision sensors, with a neural proportional integral derivative (PID), in order to develop an hexarotor image based visual servo control (IBVS) that knows the position of the robot by using a velocity vector as a reference to control the hexarotor position. This integration requires a tight coordination between control algorithms, models of the system to be controlled, sensors, hardware and software platforms and well-defined interfaces, to allow the real-time implementation, as well as the design of different processing stages with their respective communication architecture. All of these issues and others provoke the idea that real-time implementations can be considered as a difficult task. For the purpose of showing the effectiveness of the sensor integration and control algorithm to address these issues on a high nonlinear system with noisy sensors as cameras, experiments were performed on the Asctec Firefly on-board computer, including both simulation and experimenta results.

High mechanical advantage design of six-bar Stephenson mechanism for servo mechanical presses

Directory of Open Access Journals (Sweden)

Jianguo Hu

2016-06-01

Full Text Available This article proposed a two-phase design scheme of Stephenson six-bar working mechanisms for servo mechanical presses with high mechanical advantage. In the qualitative design phase, first, a Stephenson six-bar mechanism with a slide was derived from Stephenson six-bar kinematic chains. Second, based on the instant center analysis method, the relationship between mechanical advantage and some special instant centers was founded, and accordingly a primary mechanism configuration with high mechanical advantage was designed qualitatively. Then, a parameterized prototype model was established, and the influences of design parameters toward slide kinematical characteristics were analyzed. In the quantitative design phase, a multi-objective optimization model, aiming at high mechanical advantage and dwelling characteristics, was built, and a case design was done to find optimal dimensions. Finally, simulations based on the software ADAMS were conducted to compare the transmission characteristics of the optimized working mechanism with that of slide-crank mechanism and symmetrical toggle mechanism, and an experimental press was made to validate the design scheme. The simulation and experiment results show that, compared with general working mechanisms, the Stephenson six-bar working mechanism has higher mechanical advantage and better dwelling characteristics, reducing capacities and costs of servo motors effectively.

All Digital IQ Servo-System for CERN Linacs

CERN Document Server

Rohlev, A; Garoby, R

2003-01-01

A new VME based system has been developed and built at CERN for the servo loops regulating the field in the linac accelerating structure. It makes use of high speed digital In-phase/Quadrature (IQ) detection, digital processing, and digital IQ modulation. The digital processing and IQ modulation is done in a single PLD. The system incorporates continually variable set points, iterative learning, feed forward as well as extensive diagnostics and other features well suited for digital implementations. Built on a single VME card, it will be first used in the energy ramping RF chain of the CERN Heavy Ion Linac (linac 3) and later for upgrading the present proton linac (linac 2). This system serves also as a prototype for the future Superconducting Proton Linac (SPL). The design principle and the experimental results are described.

Analysis of Dead Time and Implementation of Smith Predictor Compensation in Tracking Servo Systems for Small Unmanned Aerial Vehicles

National Research Council Canada - National Science Library

Brashear , Jr, Thomas J

2005-01-01

.... Gimbaled video camera systems, designed at NPS, use two servo actuators to command line of sight orientation via serial controller while tracking a target and is termed Visual Based Target Tracking (VBTT...

Nonlinear control for a class of hydraulic servo system.

Science.gov (United States)

Yu, Hong; Feng, Zheng-jin; Wang, Xu-yong

2004-11-01

The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, etc. Aside from the nonlinear nature of hydraulic dynamics, hydraulic servo systems also have large extent of model uncertainties. To address these challenging issues, a robust state-feedback controller is designed by employing backstepping design technique such that the system output tracks a given signal arbitrarily well, and all signals in the closed-loop system remain bounded. Moreover, a relevant disturbance attenuation inequality is satisfied by the closed-loop signals. Compared with previously proposed robust controllers, this paper's robust controller based on backstepping recursive design method is easier to design, and is more suitable for implementation.

Real Time Implementation of PID and Fuzzy PD Controllers for DC-Servo Motor Based on Lab View Environment

Directory of Open Access Journals (Sweden)

Safaa M. Z. Al-Ubaidi

2012-06-01

Full Text Available This paper presents an implementation of conventional PID (CPID controller using Ziegler-Nichols rules and fuzzy PD (FPD controller for position servo motor control based on Lab View (Laboratory Virtual Instrument Engineering Workbench Environment through Data Acquisition (DAQ Device PCI- 6521 of National Instrument's and Data Acquisition Accessory Board Model (CB-68LP.CPID controller is perhaps the most well-known and most widely used in industrial applications. However, it has been known that CPID controller generally don’t work well for non-linear systems, higher order and time-delayed linear system and particularly complex and vague system. To overcome these difficulties, this paper proposes to use the FPD controller for a servo motor system instead of CPID. The parameters of servo motor used are completely unknown. The FPD structure has two-input single-output and fairly similar characteristic to its conventional counterpart and provides good performance. Simple rules base are used for FPD (nine rules only. Performance evaluation was carried out via a comparison study for the proposed control scheme and other existing control scheme, such as CPID controller. The critical point for this experiment on position system is a steady state error and settling time.  The performance showing that the FPD has less settling time and zero steady state error over its CPID. The algorithms of FPD and CPID controllers are implemented using PID, Fuzzy Logic and simulation toolkits of the Lab View environment.

Robust and Stable Disturbance Observer of Servo System for Low Speed Operation Using the Radial Basis Function Network

DEFF Research Database (Denmark)

Lee, Kyo-Beum; Blaabjerg, Frede

2005-01-01

A new scheme to estimate the moment of inertia in the servo motor drive system in very low speed is proposed in this paper. The speed estimation scheme in most servo drive systems for low speed operation is sensitive to the variation of machine parameter, especially the moment of inertia....... To estimate the motor inertia value, the observer using the Radial Basis Function Network (RBFN) is applied. A control law for stabilizing the system and adaptive laws for updating both of the weights in the RBFN and a bounding constant are established so that the whole closed-loop system is stable...... in the sense of Lyapunov. The effectiveness of the proposed inertia estimation is verified by simulations and experiments. It is concluded that the speed control performance in low speed region is improved with the proposed disturbance observer using RBFN....

Asymmetric Fuzzy Control of a Positive and Negative Pneumatic Pressure Servo System

Science.gov (United States)

Yang, Gang; Du, Jing-Min; Fu, Xiao-Yun; Li, Bao-Ren

2017-11-01

The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. In order to meet the demand of generating dynamic pressure signal in the application of the hardware-in-the-loop simulation of aerospace engineering, a positive and negative pneumatic pressure servo system is provided to implement dynamic adjustment of sealed chamber pressure. A mathematical model is established with simulation and experiment being implemented afterwards to discuss the characteristics of the system, which shows serious asymmetry in the process of charging and discharging. Based on the analysis of the system dynamics, a fuzzy proportional integral derivative (PID) controller with asymmetric fuzzy compensator is proposed. Different from conventional adjusting mechanisms employing the error and change in error of the controlled variable as input parameters, the current chamber pressure and charging or discharging state are chosen as inputs of the compensator, which improves adaptability. To verify the effectiveness and performance of the proposed controller, the comparison experiments tracking sinusoidal and square wave commands are conducted. Experimental results show that the proposed controller can obtain better dynamic performance and relatively consistent control performance across the scope of work (2-140 kPa). The research proposes a fuzzy control method to overcome asymmetry and enhance adaptability for the positive and negative pneumatic pressure servo system.

Myoelectric hand prosthesis force control through servo motor current feedback.

Science.gov (United States)

Sono, Tálita Saemi Payossim; Menegaldo, Luciano Luporini

2009-10-01

This paper presents the prehension force closed-loop control design of a mechanical finger commanded by electromyographic signal (EMG) from a patient's arm. The control scheme was implemented and tested in a mechanical finger prototype with three degrees of freedom and one actuator, driven by arm muscles EMG of normal volunteers. Real-time indirect estimation of prehension force was assessed by measuring the DC servo motor actuator current. A model of the plant comprising finger, motor, and grasped object was proposed. Model parameters were identified experimentally and a classical feedback phase-lead compensator was designed. The controlled mechanical finger was able to provide a more accurate prehension force modulation of a compliant object when compared to open-loop control.

What is the Optimal Strategy for Adaptive Servo-Ventilation Therapy?

Science.gov (United States)

Imamura, Teruhiko; Kinugawa, Koichiro

2018-05-23

Clinical advantages in the adaptive servo-ventilation (ASV) therapy have been reported in selected heart failure patients with/without sleep-disorder breathing, whereas multicenter randomized control trials could not demonstrate such advantages. Considering this discrepancy, optimal patient selection and device setting may be a key for the successful ASV therapy. Hemodynamic and echocardiographic parameters indicating pulmonary congestion such as elevated pulmonary capillary wedge pressure were reported as predictors of good response to ASV therapy. Recently, parameters indicating right ventricular dysfunction also have been reported as good predictors. Optimal device setting with appropriate pressure setting during appropriate time may also be a key. Large-scale prospective trial with optimal patient selection and optimal device setting is warranted.

Visual Servoing for an Autonomous Hexarotor Using a Neural Network Based PID Controller

Science.gov (United States)

Lopez-Franco, Carlos; Alanis, Alma Y.; Arana-Daniel, Nancy; Villaseñor, Carlos

2017-01-01

In recent years, unmanned aerial vehicles (UAVs) have gained significant attention. However, we face two major drawbacks when working with UAVs: high nonlinearities and unknown position in 3D space since it is not provided with on-board sensors that can measure its position with respect to a global coordinate system. In this paper, we present a real-time implementation of a servo control, integrating vision sensors, with a neural proportional integral derivative (PID), in order to develop an hexarotor image based visual servo control (IBVS) that knows the position of the robot by using a velocity vector as a reference to control the hexarotor position. This integration requires a tight coordination between control algorithms, models of the system to be controlled, sensors, hardware and software platforms and well-defined interfaces, to allow the real-time implementation, as well as the design of different processing stages with their respective communication architecture. All of these issues and others provoke the idea that real-time implementations can be considered as a difficult task. For the purpose of showing the effectiveness of the sensor integration and control algorithm to address these issues on a high nonlinear system with noisy sensors as cameras, experiments were performed on the Asctec Firefly on-board computer, including both simulation and experimenta results. PMID:28805689

Servo-controlled pneumatic pressure oscillator for respiratory impedance measurements and high-frequency ventilation.

Science.gov (United States)

Kaczka, David W; Lutchen, Kenneth R

2004-04-01

The ability to provide forced oscillatory excitation of the respiratory system can be useful in mechanical impedance measurements as well as high frequency ventilation (HFV). Experimental systems currently used for generating forced oscillations are limited in their ability to provide high amplitude flows or maintain the respiratory system at a constant mean pressure during excitation. This paper presents the design and implementation of a pneumatic pressure oscillator based on a proportional solenoid valve. The device is capable of providing forced oscillatory excitations to the respiratory system over a bandwidth suitable for mechanical impedance measurements and HVF. It delivers high amplitude flows (> 1.4 l/s) and utilizes a servo-control mechanism to maintain a load at a fixed mean pressure during simultaneous oscillation. Under open-loop conditions, the device exhibited a static hysteresis of approximately 7%, while its dynamic magnitude and phase responses were flat out to 10 Hz. Broad-band measurement of total harmonic distortion was approximately 19%. Under closed-loop conditions, the oscillator was able to maintain a mechanical test load at both positive and negative mean pressures during oscillatory excitations from 0.1 to 10.0 Hz. Impedance of the test load agreed closely with theoretical predictions. We conclude that this servo-controlled oscillator can be a useful tool for respiratory impedance measurements as well as HFV.

A compound control strategy combining velocity compensation with ADRC of electro-hydraulic position servo control system.

Science.gov (United States)

Gao, Bingwei; Shao, Junpeng; Yang, Xiaodong

2014-11-01

In order to enhance the anti-jamming ability of electro-hydraulic position servo control system at the same time improve the control precision of the system, a compound control strategy that combines velocity compensation with Active Disturbance Rejection Controller (ADRC) is proposed, and the working principle of the compound control strategy is given. ADRC controller is designed, and the extended state observer is used for observing internal parameters uncertainties and external disturbances, so that the disturbances of the system are suppressed effectively. Velocity compensation controller is designed and the compensation model is derived to further improve the positioning accuracy of the system and to achieve the velocity compensation without disturbance. The compound control strategy is verified by the simulation and experiment respectively, and the simulation and experimental results show that the electro-hydraulic position servo control system with ADRC controller can effectively inhibit the external disturbances, the precise positioning control is realized after introducing the velocity compensation controller, and verify that the compound control strategy is effective. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Control of xenon spatial oscillations during load follow of nuclear reactor via robust servo systems

International Nuclear Information System (INIS)

Ukai, Hiroyuki; Yada, Yukihiro; Iwazumi, Tetsuo; Morita, Yoshifumi.

1990-01-01

This paper investigates the control problem of xenon spatial oscillations in the axial direction during load following operations of a nuclear reactor. The system model is described by a one-group diffusion equation with xenon and power feedbacks and iodine-xenon dynamic equations and controlled by full-length and part-length control rods. In order to achieve the control purpose we formulate the control model as the design problem of robust servo systems for distributed parameter reactor systems. Hence the total thermal power and the axial offset are chosen as outputs to be controlled. The control law is designed based upon finite-dimensional systems which are constructed by linearizing around steady states, approximating by the Galerkin approximate method and reducing dimensions via the singular perturbation method. From a computational point of view a simple computational algorithm to obtain an approximate solution of the steady state neutron balance is developed via the perturbation method. Some results of numerical simulations are represented to show effectiveness of the theory developed in this paper. Particularly it is shown that the designed servo systems are robust against model errors with the linearization and the model truncation. (author)

A six-degree-of-freedom magnetic levitation fine stage for a high-precision and high-acceleration dual-servo stage

International Nuclear Information System (INIS)

Kim, MyeongHyeon; Jeong, Jae-heon; Gweon, DaeGab; Kim, HyoYoung

2015-01-01

This paper presents a novel six-degree-of-freedom magnetic levitation fine stage for a dual-servo stage. The proposed fine stage is levitated and actuated, using a voice coil motor actuator with a Halbach magnet array. For a dual-servo stage, fine stage performance is deeply intertwined with coarse stage performance. Because the fine stage is installed over the coarse stage, the overall size of the fine stage can be limited by the moving plate of the coarse stage. Therefore, magnetic flux modeling and optimization are performed to manufacture optimal fine stages. To control the fine stage, actuator kinetics and sensor kinematics are proposed. Homing control is implemented by using linear variable differential transformers, whereas fine control is implemented by capacitance sensors and laser interferometers. Finally, experimental results of in-position stability, moving range, and repeatability are presented. (paper)

Application of simple adaptive control to water hydraulic servo cylinder system

Science.gov (United States)

Ito, Kazuhisa; Yamada, Tsuyoshi; Ikeo, Shigeru; Takahashi, Koji

2012-09-01

Although conventional model reference adaptive control (MRAC) achieves good tracking performance for cylinder control, the controller structure is much more complicated and has less robustness to disturbance in real applications. This paper discusses the use of simple adaptive control (SAC) for positioning a water hydraulic servo cylinder system. Compared with MRAC, SAC has a simpler and lower order structure, i.e., higher feasibility. The control performance of SAC is examined and evaluated on a water hydraulic servo cylinder system. With the recent increased concerns over global environmental problems, the water hydraulic technique using pure tap water as a pressure medium has become a new drive source comparable to electric, oil hydraulic, and pneumatic drive systems. This technique is also preferred because of its high power density, high safety against fire hazards in production plants, and easy availability. However, the main problems for precise control in a water hydraulic system are steady state errors and overshoot due to its large friction torque and considerable leakage flow. MRAC has been already applied to compensate for these effects, and better control performances have been obtained. However, there have been no reports on the application of SAC for water hydraulics. To make clear the merits of SAC, the tracking control performance and robustness are discussed based on experimental results. SAC is confirmed to give better tracking performance compared with PI control, and a control precision comparable to MRAC (within 10 μm of the reference position) and higher robustness to parameter change, despite the simple controller. The research results ensure a wider application of simple adaptive control in real mechanical systems.

Deserción escolar de los estudiantes de educación básica de la Unidad Educativa "Sagrado Corazón de Jesús" de la ciudad de Latacunga durante los últimos tres años lectivos

OpenAIRE

Yépez Yumbilla, Vilma

2013-01-01

La presente investigación trata, en términos generales, sobre la deserción escolar en Latinoamérica, en el Ecuador, en la Provincia de Cotopaxi y en particular en la Unidad Educativa Sagrado Corazón de Jesús de Latacunga, para determinar los factores que la generan. Para ellose la ha elaborado en tres capítulos con las siguientes temáticas: El primer capítulo presenta la fundamentación teórica sobre la deserción escolar e identifica las políticas educativas orientadas a dism...

Reconfigurable Flight Control Design using a Robust Servo LQR and Radial Basis Function Neural Networks

Science.gov (United States)

Burken, John J.

2005-01-01

This viewgraph presentation reviews the use of a Robust Servo Linear Quadratic Regulator (LQR) and a Radial Basis Function (RBF) Neural Network in reconfigurable flight control designs in adaptation to a aircraft part failure. The method uses a robust LQR servomechanism design with model Reference adaptive control, and RBF neural networks. During the failure the LQR servomechanism behaved well, and using the neural networks improved the tracking.

Development And Evaluation Of A Low Cost Servo-valve For Liquid Inputs Application [desenvolvimento E Avaliação De Uma Servoválvula De Baixo Custo Para A Aplicação De Insumos Líquidos

OpenAIRE

Johann A.L.; Russo E.; Cappelli N.L.; Umezu C.K.

2006-01-01

The present work aimed the development of a low cost servo-valve that answers to an electronic control signal, for variable rates liquid inputs application. A literature research to define which valve type should be used was made. A mechanically activated proportional valve with an electronically controlled servo-engine was designed and evaluated. Since developed the servo-valve, the system was submited to a number of tests .The evaluation of its behavior was obtained in terms of repeatabilit...

De la arqueología simbólica del paisaje a la arqueología de los paisajes sagrados

Directory of Open Access Journals (Sweden)

Santos Estevez, Manuel

1997-12-01

Full Text Available This paper deals with the different models of landscapes found in the Prehistory and History of the northwest area of the Iberian Peninsula. We consider both the pattern of settlement and land-use and the arrangement of supralocal territorial units. This study particularly focuses on the form of a symbolic or sacred landscape in a specific part of our research area. This sacred landscape would have represented the models of social landscapes in each period. By these means, we try to show the different patterns of rationality that lie behind the conception of sacred through some distinctive cultural periods; the aim is to show the contribution of each period for the cumulative construction of the present day landscape and to decode a different conception of landscape for each phase. The analysis has been made for a single zone within the core area of Galician Bronze Age rock art, between Campo Lameiro and Cotobade municipalities (Pontevedra. We think we have discovered elements of that symbolic meaning in the Bronze Age, the Iron Age, the Roman period, the early Middle Ages and the Galician traditional rural world. Far away from the proposal of secular survivals, our analysis try to show how each one of those land marks is built up from a specific conception of landscape, although all of them coincide in marking an area endowed with peculiar natural conditions, but given different interpretations in each period.

Se estudian los diferentes modelos de paisaje que se suceden en la Prehistoria e Historia de una comarca del noroeste de la Península Ibérica. Se analizan tanto la distribución del poblamiento y el uso del suelo a la luz de datos geográficos y arqueológicos, como la articulación de organizaciones territoriales supralocales. En concreto se observa la conformación de un espacio simbólico o sagrado en un sector concreto de la zona de estudio que habría servido como recurso fundamental para configurar y expresar los modelos de

Using Feedback Error Learning for Control of Electro Hydraulic Servo System by Laguerre

Directory of Open Access Journals (Sweden)

Amir Reza Zare Bidaki

2014-01-01

Full Text Available In this paper, a new Laguerre controller is proposed to control the electro hydraulic servo system. The proposed controller uses feedback error learning method and leads to significantly improve performance in terms of settling time and amplitude of control signal rather than other controllers. All derived results are validated by simulation of nonlinear mathematical model of the system. The simulation results show the advantages of the proposed method for improved control in terms of both settling time and amplitude of control signal.

O parto: encontro com o sagrado

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Adriana Tanese Nogueira

2006-01-01

Full Text Available El artículo objetiva presentar la cuestión de la humanización del parto en sus fundamentos culturales y antropológicos, con la intención de añadir el punto de vista no médico al debate. Fueran utilizados los pensamientos de dos conocidos estudiosos de las religiones: Rudolf Otto y Mircea Eliade, pero fueran las referencias teóricas que forman la filosofía y la práctica alquímica que hay sido utilizadas para analizar a experiencia de una mujer quien a las cuarenta semanas de gestación invierte el camino previsto en la búsqueda de una experiencia de parto la cual se reveló como extraordinaria. El resultado de la reflexión muestra las profundas ramificaciones que la humanización del parto implica para las mujeres, sea en términos de su dimensión psicológica como de su actuación en cuanto ciudadana, madre y mujer. Finalizamos apuntando los nuevos rumbos que la humanización del parto acarrea para sus actores, en cuanto un amplio movimiento de transformación del paradigma cultural y obstétrico.

Decommissioning of hot cells using a hydraulically powered servo manipulator

International Nuclear Information System (INIS)

Asquith, J.D.; Loughborough, D.

1993-01-01

This paper describes the preparations and initial trials involved in remotely dismantling the containment boxes within two concrete shielded hot cells at Harwell Laboratory using a hydraulically powered servo manipulator, ARTISAN. The manipulator deploys a variety of tools for cutting operations. The modular design has enabled it to be specifically configured for this application by adjusting the link lengths using spacers between the joints. In addition to the remote handling requirements, a new posting and ventilation system for the facility is outlined. Trials with ARTISAN in an in-active mock-up have now been successfully completed, and the manipulator is installed in the active facility. The considerations and approach adopted in this project are typical of many situations where remote techniques are required for decommissioning activities. (author)

A new state space model for the NASA/JPL 70-meter antenna servo controls

Science.gov (United States)

Hill, R. E.

1987-01-01

A control axis referenced model of the NASA/JPL 70-m antenna structure is combined with the dynamic equations of servo components to produce a comprehansive state variable (matrix) model of the coupled system. An interactive Fortran program for generating the linear system model and computing its salient parameters is described. Results are produced in a state variable, block diagram, and in factored transfer function forms to facilitate design and analysis by classical as well as modern control methods.

AeroPropulsoServoElasticity: Dynamic Modeling of the Variable Cycle Propulsion System

Science.gov (United States)

Kopasakis, George

2012-01-01

This presentation was made at the 2012 Fundamental Aeronautics Program Technical Conference and it covers research work for the Dynamic Modeling of the Variable cycle Propulsion System that was done under the Supersonics Project, in the area of AeroPropulsoServoElasticity. The presentation covers the objective for the propulsion system dynamic modeling work, followed by the work that has been done so far to model the variable Cycle Engine, modeling of the inlet, the nozzle, the modeling that has been done to model the affects of flow distortion, and finally presenting some concluding remarks and future plans.

Data-driven adaptive fractional order PI control for PMSM servo system with measurement noise and data dropouts.

Science.gov (United States)

Xie, Yuanlong; Tang, Xiaoqi; Song, Bao; Zhou, Xiangdong; Guo, Yixuan

2018-04-01

In this paper, data-driven adaptive fractional order proportional integral (AFOPI) control is presented for permanent magnet synchronous motor (PMSM) servo system perturbed by measurement noise and data dropouts. The proposed method directly exploits the closed-loop process data for the AFOPI controller design under unknown noise distribution and data missing probability. Firstly, the proposed method constructs the AFOPI controller tuning problem as a parameter identification problem using the modified l p norm virtual reference feedback tuning (VRFT). Then, iteratively reweighted least squares is integrated into the l p norm VRFT to give a consistent compensation solution for the AFOPI controller. The measurement noise and data dropouts are estimated and eliminated by feedback compensation periodically, so that the AFOPI controller is updated online to accommodate the time-varying operating conditions. Moreover, the convergence and stability are guaranteed by mathematical analysis. Finally, the effectiveness of the proposed method is demonstrated both on simulations and experiments implemented on a practical PMSM servo system. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Development of an EtherCAT enabled digital servo controller for the Green Bank Telescope

Science.gov (United States)

Whiteis, Peter G.; Mello, Melinda J.

2012-09-01

EtherCAT (Ethernet for Control Automation Technology) is gaining wide spread popularity in the automation industry as a real time field bus based on low cost, Ethernet hardware. EtherCAT maximizes use of 100Mbps Ethernet hardware by using a collision free ring topology, efficient Ethernet frame utilization (> 95%), and data exchange "on the fly". These characteristics enable EtherCAT to achieve Master to Slave node data exchange rates of > 1000 Hz. The Green Bank Telescope, commissioned in 2000, utilizes an analog control system for motion control of 8 elevation and 16 azimuth motors. This architecture, while sufficient for observations at frequencies up to 50GHz, has significant limitations for the current scientific goals of observing at 115GHz. Accordingly, the Green Bank staff has embarked on a servo upgrade project to develop a digital servo system which accommodates development and implementation of advanced control algorithms. This paper describes how the new control system requirements, use of existing infrastructure and budget constraints led us to define a distributed motion control architecture where EtherCAT real-time Ethernet was selected as the communication bus. Finally, design details are provided that describe how NRAO developed a custom EtherCAT-enabled motor controller interface for the GBT's legacy motor drives in order to provide technical benefits and flexibility not available in commercial products.

Enhanced control of a flexure-jointed micromanipulation system using a vision-based servoing approach

Science.gov (United States)

Chuthai, T.; Cole, M. O. T.; Wongratanaphisan, T.; Puangmali, P.

2018-01-01

This paper describes a high-precision motion control implementation for a flexure-jointed micromanipulator. A desktop experimental motion platform has been created based on a 3RUU parallel kinematic mechanism, driven by rotary voice coil actuators. The three arms supporting the platform have rigid links with compact flexure joints as integrated parts and are made by single-process 3D printing. The mechanism overall size is approximately 250x250x100 mm. The workspace is relatively large for a flexure-jointed mechanism, being approximately 20x20x6 mm. A servo-control implementation based on pseudo-rigid-body models (PRBM) of kinematic behavior combined with nonlinear-PID control has been developed. This is shown to achieve fast response with good noise-rejection and platform stability. However, large errors in absolute positioning occur due to deficiencies in the PRBM kinematics, which cannot accurately capture flexure compliance behavior. To overcome this problem, visual servoing is employed, where a digital microscopy system is used to directly measure the platform position by image processing. By adopting nonlinear PID feedback of measured angles for the actuated joints as inner control loops, combined with auxiliary feedback of vision-based measurements, the absolute positioning error can be eliminated. With controller gain tuning, fast dynamic response and low residual vibration of the end platform can be achieved with absolute positioning accuracy within ±1 micron.

Micro-vision servo control of a multi-axis alignment system for optical fiber assembly

International Nuclear Information System (INIS)

Chen, Weihai; Yu, Fei; Qu, Jianliang; Chen, Wenjie; Zhang, Jianbin

2017-01-01

This paper describes a novel optical fiber assembly system featuring a multi-axis alignment function based on micro-vision feedback control. It consists of an active parallel alignment mechanism, a passive compensation mechanism, a micro-gripper and a micro-vision servo control system. The active parallel alignment part is a parallelogram-based design with remote-center-of-motion (RCM) function to achieve precise rotation without fatal lateral motion. The passive mechanism, with five degrees of freedom (5-DOF), is used to implement passive compensation for multi-axis errors. A specially designed 1-DOF micro-gripper mounted onto the active parallel alignment platform is adopted to grasp and rotate the optical fiber. A micro-vision system equipped with two charge-coupled device (CCD) cameras is introduced to observe the small field of view and obtain multi-axis errors for servo feedback control. The two CCD cameras are installed in an orthogonal arrangement—thus the errors can be easily measured via the captured images. Meanwhile, a series of tracking and measurement algorithms based on specific features of the target objects are developed. Details of the force and displacement sensor information acquisition in the assembly experiment are also provided. An experiment demonstrates the validity of the proposed visual algorithm by achieving the task of eliminating errors and inserting an optical fiber to the U-groove accurately. (paper)

Velocity control of servo systems using an integral retarded algorithm.

Science.gov (United States)

Ramírez, Adrián; Garrido, Rubén; Mondié, Sabine

2015-09-01

This paper presents a design technique for the delay-based controller called Integral Retarded (IR), and its applications to velocity control of servo systems. Using spectral analysis, the technique yields a tuning strategy for the IR by assigning a triple real dominant root for the closed-loop system. This result ultimately guarantees a desired exponential decay rate σ(d) while achieving the IR tuning as explicit function of σ(d) and system parameters. The intentional introduction of delay allows using noisy velocity measurements without additional filtering. The structure of the controller is also able to avoid velocity measurements by using instead position information. The IR is compared to a classical PI, both tested in a laboratory prototype. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

O RELATO DA INFÂNCIA DE JESUS SEGUNDO O EVANGELHO DE MATEUS

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Felipe Costa Silva

2017-08-01

Full Text Available Os relatos da infância de Jesus contidos no evangelho de Mateus, nos capítulos 1 e 2, refletem o plano teológico do autor sagrado, que situa Jesus de Nazaré, o Messias esperado, na história do povo de Israel, e, por conseguinte, na história da humanidade. O objetivo desta breve investigação bíblica e revisão bibliográfica é evidenciar os elementos centrais da infância do Nazareno como coordenadas necessárias para uma compreensão da historicidade dos acontecimentos frente à reflexão teológica, bem como da articulação entre os dados da fé e da história. A metodologia utilizada é a de uma leitura crítica da Bíblia com análise da bibliografia exegética sobre o tema. Esperamos com este método lançar uma luz sobre a leitura do texto com ênfase nos elementos históricos como forma de complementação à investigação cristológica. Acreditamos que a investigação da pessoa histórica de Jesus não contradiz sua qualidade de Cristo da fé, quando feita em respeito dos textos sagrados.

Compensating Unknown Time-Varying Delay in Opto-Electronic Platform Tracking Servo System

Directory of Open Access Journals (Sweden)

Ruihong Xie

2017-05-01

Full Text Available This paper investigates the problem of compensating miss-distance delay in opto-electronic platform tracking servo system. According to the characteristic of LOS (light-of-sight motion, we setup the Markovian process model and compensate this unknown time-varying delay by feed-forward forecasting controller based on robust H∞ control. Finally, simulation based on double closed-loop PI (Proportion Integration control system indicates that the proposed method is effective for compensating unknown time-varying delay. Tracking experiments on the opto-electronic platform indicate that RMS (root-mean-square error is 1.253 mrad when tracking 10° 0.2 Hz signal.

La experiencia cultural de lo sagrado a través de la geometría de los albores de la humanidad hasta la aritmosofía de Pitágoras

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Óscar Castro García

2015-03-01

Full Text Available La Geometría llamada «Sagrada» es una metáfora de la Ordenación del Universo, la huella digital de la Creación. Este es un estudio interdisciplinar donde se ofrece información sobre diversas materias que van desde teoría de la estética, historia del arte, hasta la mecánica cuántica, pasando por la simbólica, la antropología de las religiones, la microbiología y la cosmología. El interés de este estudio es la visión heurística y transdisciplinar que se proyecta sobre un conocimiento perenne y holístico del sentido de la geometría como una semiótica de lo sagrado en la vida. Comenzamos nuestro camino en los albores de la humanidad, en la que la geometría estaba vinculada con la posibilidad de comunicación. Sobre todo de forma que su semiótica no fuese únicamente fuente de gestión social y económica. Sobre todo hay una fuerte motivación de comunicación con lo tremendo, lo magnífico, lo inefable y lo sagrado (Mircea Eliade, o «lo santo» (Rudolf Otto. Veremos cómo dicha vinculación semiótico-simbólica adquiere cada vez mayor complejidad, aunque su grado de abstracción ya es sutil desde el neolítico. Lo complejo viene en la aplicación de la matemática geométrica a la arquitectura (desde los megalitos hasta los templos y pirámides, pasando por los zigurats y sus operaciones mágicas, teúrgicas y místicas. Nos concentraremos en ver algunas características de las construcciones hasta llegar a Pitágoras de Samos en cuya escuela de geometría se vive una edad de oro, en el sentido pleromático del conocimiento sapiencial de las matemáticas: la armonía del número y del ritmo.

Cylinder Position Servo Control Based on Fuzzy PID

Directory of Open Access Journals (Sweden)

Shibo Cai

2013-01-01

Full Text Available The arbitrary position control of cylinder has always been the hard challenge in pneumatic system. We try to develop a cylinder position servo control method by combining fuzzy PID with the theoretical model of the proportional valve-controlled cylinder system. The pressure differential equation of cylinder, pressure-flow equation of proportional valve, and moment equilibrium equation of cylinder are established. And the mathematical models of the cylinder driving system are linearized. Then fuzzy PID control algorithm is designed for the cylinder position control, including the detail analysis of fuzzy variables and domain, fuzzy logic rules, and defuzzification. The stability of the proposed fuzzy PID controller is theoretically proved according to the small gain theorem. Experiments for targets position of 250 mm, 300 mm, and 350 mm were done and the results showed that the absolute error of the position control is less than 0.25 mm. And comparative experiment between fuzzy PID and classical PID verified the advantage of the proposed algorithm.

Servo-elastic dynamics of a hydraulic actuator pitching a blade with large deflections

DEFF Research Database (Denmark)

Hansen, Morten Hartvig; Kallesøe, Bjarne Skovmose

2007-01-01

This paper deals with the servo-elastic dynamics of a hydraulic pitch actuator acting on a largely bend wind turbine blade. The compressibility of the oil and flexibility of the hoses introduce a dynamic mode in the pitch bearing degree of freedom. This mode may obtain negative damping...... if the proportional gain on the actuator position error is defined too large relative to the viscous forces in the hydraulic system and the total rotational inertia of the pitch bearing degree of freedom. A simple expression for the stability limit of this proportional gain is derived for tuning the gain based...

A new linearized equation for servo valve in hydraulic control systems

International Nuclear Information System (INIS)

Kim, Tae Hyung; Lee, Ill Yeong

2002-01-01

In the procedure of the hydraulic control system analysis, a linearized approximate equation described by the first order term of Taylor's series has been widely used. Such a linearized equation is effective just near the operating point. And, as of now, there are no general standards on how to determine the operating point of a servo valve in the process of applying the linearized equation. So, in this study, a new linearized equation for valve characteristics is proposed as a modified form of the existing linearized equation. And, a method for selecting an optimal operating point is proposed for the new linearized equation. The effectiveness of the new linearized equation is confirmed through numerical simulations and experiments for a model hydraulic control system

RELIGIÃO GUARANI NHANDEWA: UMA COMPLEXA ORGANIZAÇÃO E RECRIAÇÃO PARA A VIDA E A EDUCAÇÃO.

Directory of Open Access Journals (Sweden)

Rosangela Célia Faustino

2010-05-01

Full Text Available O presente texto apresenta um estudo sobre aspectos históricos, culturais e religiosos dos Guarani Nhandewa evidenciando como a religião, antiga e atual são complexas em detalhes sendo elemento importantíssimo na cosmovisão dos grupos pois permeia todos os domínios da vida, da luta pela sobrevivência e permanência enquanto grupo étnico diferenciado. Destaca-se o relevante caráter da educação entendida como um dom sagrado, recebido de Nhanderu, mas que deve ser exercitada e aprendida por toda a vida pela mediação daqueles que sabem mais, os adultos e os mais velhos.

Visual servo simulation of EAST articulated maintenance arm robot

Energy Technology Data Exchange (ETDEWEB)

Yang, Yang, E-mail: yangyang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, 350 Shushanhu Rd, Hefei, Anhui (China); Song, Yuntao; Pan, Hongtao; Cheng, Yong; Feng, Hansheng [Institute of Plasma Physics, Chinese Academy of Sciences, 350 Shushanhu Rd, Hefei, Anhui (China); Wu, Huapeng [Lappeenranta University of Technology, Skinnarilankatu 34, Lappeenranta (Finland)

2016-03-15

For the inspection and light-duty maintenance of the vacuum vessel in the EAST tokamak, a serial robot arm, called EAST articulated maintenance arm, is developed. Due to the 9-m-long cantilever arm, the large flexibility of the EAMA robot introduces a problem in the accurate positioning. This article presents an autonomous robot control to cope with the robot positioning problem, which is a visual servo approach in context of tile grasping for the EAMA robot. In the experiments, the proposed method was implemented in a simulation environment to position and track a target graphite tile with the EAMA robot. As a result, the proposed visual control scheme can successfully drive the EAMA robot to approach and track the target tile until the robot reaches the desired position. Furthermore, the functionality of the simulation software presented in this paper is proved to be suitable for the development of the robotic and computer vision application.

Visual servo simulation of EAST articulated maintenance arm robot

International Nuclear Information System (INIS)

Yang, Yang; Song, Yuntao; Pan, Hongtao; Cheng, Yong; Feng, Hansheng; Wu, Huapeng

2016-01-01

For the inspection and light-duty maintenance of the vacuum vessel in the EAST tokamak, a serial robot arm, called EAST articulated maintenance arm, is developed. Due to the 9-m-long cantilever arm, the large flexibility of the EAMA robot introduces a problem in the accurate positioning. This article presents an autonomous robot control to cope with the robot positioning problem, which is a visual servo approach in context of tile grasping for the EAMA robot. In the experiments, the proposed method was implemented in a simulation environment to position and track a target graphite tile with the EAMA robot. As a result, the proposed visual control scheme can successfully drive the EAMA robot to approach and track the target tile until the robot reaches the desired position. Furthermore, the functionality of the simulation software presented in this paper is proved to be suitable for the development of the robotic and computer vision application.

Servo scanning 3D micro EDM for array micro cavities using on-machine fabricated tool electrodes

Science.gov (United States)

Tong, Hao; Li, Yong; Zhang, Long

2018-02-01

Array micro cavities are useful in many fields including in micro molds, optical devices, biochips and so on. Array servo scanning micro electro discharge machining (EDM), using array micro electrodes with simple cross-sectional shape, has the advantage of machining complex 3D micro cavities in batches. In this paper, the machining errors caused by offline-fabricated array micro electrodes are analyzed in particular, and then a machining process of array servo scanning micro EDM is proposed by using on-machine fabricated array micro electrodes. The array micro electrodes are fabricated on-machine by combined procedures including wire electro discharge grinding, array reverse copying and electrode end trimming. Nine-array tool electrodes with Φ80 µm diameter and 600 µm length are obtained. Furthermore, the proposed process is verified by several machining experiments for achieving nine-array hexagonal micro cavities with top side length of 300 µm, bottom side length of 150 µm, and depth of 112 µm or 120 µm. In the experiments, a chip hump accumulates on the electrode tips like the built-up edge in mechanical machining under the conditions of brass workpieces, copper electrodes and the dielectric of deionized water. The accumulated hump can be avoided by replacing the water dielectric by an oil dielectric.

Design of Servo Scheme and Drive Electronics for the Integrated Electrohydraulic Actuation System of RLV-TD

Science.gov (United States)

Kurian, Priya C.; Gopinath, Anish; Shinoy, K. S.; Santhi, P.; Sundaramoorthy, K.; Sebastian, Baby; Jaya, B.; Namboodiripad, M. N.; Mookiah, T.

2017-12-01

Reusable Launch Vehicle-Technology Demonstrator (RLV-TD) is a system which has the ability to carry a payload from the earth's surface to the outer space more than once. The control actuation forms the major component of the control system and it actuates the control surfaces of the RLV-TD based on the control commands. Eight electro hydraulic actuators were used in RLV-TD for vectoring the control surfaces about their axes. A centralised Hydraulic Power Generating Unit (HPU) was used for powering the eight actuators located in two stages. The actuation system had to work for the longest ever duration of about 850 s for an Indian launch vehicle. High bandwidth requirement from autopilot was met by the servo design using the nonlinear mathematical model. Single Control Electronics which drive four electrohydraulic actuators was developed for each stage. High power electronics with soft start scheme was realized for driving the BLDC motor which is the prime mover for hydraulic pump. Many challenges arose due to single HPU for two stages, uncertainty of aero load, higher bandwidth requirements etc. and provisions were incorporated in the design to successfully overcome them. This paper describes the servo design and control electronics architecture of control actuation system.

Speed tracking control of pneumatic motor servo systems using observation-based adaptive dynamic sliding-mode control

Science.gov (United States)

Chen, Syuan-Yi; Gong, Sheng-Sian

2017-09-01

This study aims to develop an adaptive high-precision control system for controlling the speed of a vane-type air motor (VAM) pneumatic servo system. In practice, the rotor speed of a VAM depends on the input mass air flow, which can be controlled by the effective orifice area (EOA) of an electronic throttle valve (ETV). As the control variable of a second-order pneumatic system is the integral of the EOA, an observation-based adaptive dynamic sliding-mode control (ADSMC) system is proposed to derive the differential of the control variable, namely, the EOA control signal. In the ADSMC system, a proportional-integral-derivative fuzzy neural network (PIDFNN) observer is used to achieve an ideal dynamic sliding-mode control (DSMC), and a supervisor compensator is designed to eliminate the approximation error. As a result, the ADSMC incorporates the robustness of a DSMC and the online learning ability of a PIDFNN. To ensure the convergence of the tracking error, a Lyapunov-based analytical method is employed to obtain the adaptive algorithms required to tune the control parameters of the online ADSMC system. Finally, our experimental results demonstrate the precision and robustness of the ADSMC system for highly nonlinear and time-varying VAM pneumatic servo systems.

Extended state observer–based fractional order proportional–integral–derivative controller for a novel electro-hydraulic servo system with iso-actuation balancing and positioning

Directory of Open Access Journals (Sweden)

Qiang Gao

2015-12-01

Full Text Available Aiming at balancing and positioning of a new electro-hydraulic servo system with iso-actuation configuration, an extended state observer–based fractional order proportional–integral–derivative controller is proposed in this study. To meet the lightweight requirements of heavy barrel weapons with large diameters, an electro-hydraulic servo system with a three-chamber hydraulic cylinder is especially designed. In the electro-hydraulic servo system, the balance chamber of the hydraulic cylinder is used to realize active balancing of the unbalanced forces, while the driving chambers consisting of the upper and lower chambers are adopted for barrel positioning and dynamic compensation of external disturbances. Compared with conventional proportional–integral–derivative controllers, the fractional order proportional–integral–derivative possesses another two adjustable parameters by expanding integer order to arbitrary order calculus, resulting in more flexibility and stronger robustness of the control system. To better compensate for strong external disturbances and system nonlinearities, the extended state observer strategy is further introduced to the fractional order proportional–integral–derivative control system. Numerical simulation and bench test indicate that the extended state observer–based fractional order proportional–integral–derivative significantly outperforms proportional–integral–derivative and fractional order proportional–integral–derivative control systems with better control accuracy and higher system robustness, well demonstrating the feasibility and effectiveness of the proposed extended state observer–based fractional order proportional–integral–derivative control strategy.

Development of Servo Motor Trainer for Basic Control System in Laboratory of Electrical Engineering Control System Faculty of Engineering Universitas Negeri Surabaya

Science.gov (United States)

Endryansyah; Wanarti Rusimamto, Puput; Ridianto, Adam; Sugiarto, Hariyadi

2018-04-01

In the Department of Electrical Engineering FT Unesa, there are 3 majors: S1 Electrical Engineering Education, S1 Electrical Engineering, and D3 Electrical Engineering. Courses the Basic System Settings go to in the curriculum of the three programs. Team lecturer college of basic system settings seek learning innovation, focused on the development of trainer to student practicum at the laboratory of systems control. Trainer developed is a servo motor along with the lab module that contains a wide variety of theories about the servo motor and guide the practicum. This research type is development research using methods Research & development (R & D). In which the steps are applied in this study is as follows: pay attention to the potential and existing problems, gather information and study the literature, design the product, validate the design, revise the design, a limited trial. The results of the validation of learning device in the form of modules and trainer obtained as follows: score validation of learning device is 3,64; score validation lab module Servo Motor is 3,47; and questionnaire responses of students is 3,73. The result of the whole validation value is located in the interval >of 3.25 s/d 4 with the category of “Very Valid”, so it can be concluded that all instruments have a level of validity “Very Valid” and worthy of use for further learning.

Arquitectura Pentecostal: entre lo sagrado y lo profano

Directory of Open Access Journals (Sweden)

Rodrigo Vidal Rojas

2011-06-01

Full Text Available Delimitar a noção da Arquitetura Pentecostal, para revelar e compreender alguns elementos espaciais, formais, simbólicos, materiais e prediais que contribuam a identificar as qualidades próprias dos templos do movimento Pentecostal chileno, é a finalidade deste artigo. Para isso primeiramente, analisa-se a dimensão material do movimento Pentecostal, pondo ênfase nos fundamentos bíblicos da ideia implícita de templo presente no discurso doutrinal. Logo, para entender de que maneira o contexto histórico e a inserção socioeconômica do movimento pentecostal se funde com a concepção teológica do templo, mencionam-se alguns marcos do desenvolvimento histórico do movimento pentecostal chileno. Finalmente, propõe-se uma interpretação da arquitetura Pentecostal, a partir do estudo de alguns templos chilenos selecionados.

An ultrasonic sensor controller for mapping and servo control in robotic systems

International Nuclear Information System (INIS)

Drotning, W.D.; Garcia, P. Jr.

1993-03-01

An ultrasonic sensor controller has been developed and applied in a variety of robotic systems for operation in hazardous environments. The controller consists of hardware and software that control multiple ultrasonic range sensors and provide workspace information to robot controllers for rapid, safe, and reliable operation in hazardous and remote environments. The hardware consists of a programmable multichannel controller that resides on a VMEbus for high speed communication to a multiprocessor architecture. The sensor controller has been used in a number of applications, which include providing high precision range information for proximity servo control of robots, and performing surface and obstacle mapping functions for safe path planning of robots in unstructured environments

A model reference and sensitivity model-based self-learning fuzzy logic controller as a solution for control of nonlinear servo systems

NARCIS (Netherlands)

Kovacic, Z.; Bogdan, S.; Balenovic, M.

1999-01-01

In this paper, the design, simulation and experimental verification of a self-learning fuzzy logic controller (SLFLC) suitable for the control of nonlinear servo systems are described. The SLFLC contains a learning algorithm that utilizes a second-order reference model and a sensitivity model

Senhora das Águas: Memórias da antiga Procissão de Navegantes do Porto de Pelotas - RS

OpenAIRE

Farinha, Alessandra Buriol

2012-01-01

O presente trabalho tem como principal objetivo recuperar as memórias da antiga Procissão de Nossa Senhora dos Navegantes na regiãodo Porto de Pelotas. Da mesma forma, busca elucidar de que forma ocorreu sua descaracterização, seu esquecimento. A Festa de Navegantes ocorreu pela primeira vez em Pelotas em 1932, no bairro portuário da cidade, organizada pela Matriz Sagrado Coração de Jesus, conhecida como Igreja do Porto. No evento religioso, ocorria procissão terrestre...

L1 adaptive control of uncertain gear transmission servo systems with deadzone nonlinearity.

Science.gov (United States)

Zuo, Zongyu; Li, Xiao; Shi, Zhiguang

2015-09-01

This paper deals with the adaptive control problem of Gear Transmission Servo (GTS) systems in the presence of unknown deadzone nonlinearity and viscous friction. A global differential homeomorphism based on a novel differentiable deadzone model is proposed first. Since there exist both matched and unmatched state-dependent unknown nonlinearities, a full-state feedback L1 adaptive controller is constructed to achieve uniformly bounded transient response in addition to steady-state performance. Finally, simulation results are included to show the elimination of limit cycles, in addition to demonstrating the main results in this paper. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

O Sagrado e a Ritualidade Diante da Morte / The Sacred and the Rituality When Facing Death

Directory of Open Access Journals (Sweden)

João Batista Alves de Oliveira

2012-06-01

Full Text Available Morrer, expressão fria, não inspiradora, devastadora de sonhos, de amores. Certeza única em nossa vida. Ocorre, mais cedo ou mais tarde, de forma branda ou arrebatadora, sutil ou amargurante, suave ou sofrida. Momento em que precisamos agir de determinado jeito para elaborarmos e vivermos a perda, acompanhando a despedida de quem nos é caro e para convivermos adequadamente com a fase do luto. Aí se faz importante a realização do ritual, o qual andou se perdendo na atualidade, não valorizado pela frieza asséptica da morte moderna e que precisa ter retomado o seu valor, já que “... realizar a ação ritual significa conter o pensamento dentro das malhas da ação clara e significativa”.1 Não se pode atribuir uma fórmula ou um valor fixo ao rito, mas é certo que não é inútil. Ele representa a nossa história: quem somos, de onde viemos, para onde vamos, porque amamos e também, porque ali, no rito de morte, estamos sofrendo. É o momento de olharmos para aquele de quem nos despedimos e nos enxergarmos nele; de repensar o valor de nossa história, a intensidade do nosso amor, os caminhos e descaminhos de nossa vida juntos. Todo rito de morte, quando esta ocorre lentamente, como no caso de doenças prolongadas, nos prepara para a vivência do luto. Isso é fundamental, pois “o rito equivale a uma ação formal prescrita para ocasiões que vão além da rotina cotidiana teológica, correspondendo uma referência à crença em seus poderes místicos”.1 Nesse momento, precisamos dessas crenças, de apegarmo-nos ao Sagrado, independente da concepção que cada um faça deste.

Transmission Characteristics on Wire-Driven Links of a Bridge Transported Servo Manipulator for the ACP Equipment Maintenance

International Nuclear Information System (INIS)

Park, Byung Suk; Jin, Jae Hyun; Song, Tae Gil; Kim, Sung Hyun; Yoon, Ji Sup

2004-01-01

A bridge transported servo manipulator (BTSM) system for the advanced spent fuel conditioning process (ACP) has been developed to overcome the limitation of access, which is a drawback of mechanical master-slave manipulators (MSM) for the equipment maintenance. The servo manipulator is composed of a slave manipulator attached to the telescoping tube sets equipped with the overhead bridge installed at a hot cell and a master manipulator installed at an out-of-hot cell. Each manipulator has 7 degrees-of-freedom (DOF): a body rotation, an upper-arm tilt, a lower-arm tilt, a lower-arm rotation, a wrist pan and tilt, and a grasp motion. A wire-driven mechanism for a lower-arm rotation, a wrist pan and tilt, and a grasp motion of the manipulator has been adopted to increase the handling capacity compared to the manipulator weight and decrease the friction. The main disadvantage of the wire-driven mechanism is that if one link is in motion, other links can be affected. In this paper, the transmission characteristics among the wire-driven links have been formulated to overcome this drawback. The unexpected behaviors are confirmed by analyses of transmission characteristics as well as experiments. Also, the experimental results show that the unexpected behaviors are greatly decreased by the proposed compensation equations

Theoretical Design and First Test in Laboratory of a Composite Visual Servo-Based Target Spray Robotic System

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Dongjie Zhao

2016-01-01

Full Text Available In order to spray onto the canopy of interval planting crop, an approach of using a target spray robot with a composite vision servo system based on monocular scene vision and monocular eye-in-hand vision was proposed. Scene camera was used to roughly locate target crop, and then the image-processing methods for background segmentation, crop canopy centroid extraction, and 3D positioning were studied. Eye-in-hand camera was used to precisely determine spray position of each crop. Based on the center and area of 2D minimum-enclosing-circle (MEC of crop canopy, a method to calculate spray position and spray time was determined. In addition, locating algorithm for the MEC center in nozzle reference frame and the hand-eye calibration matrix were studied. The processing of a mechanical arm guiding nozzle to spray was divided into three stages: reset, alignment, and hovering spray, and servo method of each stage was investigated. For preliminary verification of the theoretical studies on the approach, a simplified experimental prototype containing one spray mechanical arm was built and some performance tests were carried out under controlled environment in laboratory. The results showed that the prototype could achieve the effect of “spraying while moving and accurately spraying on target.”

Design of an Image-Servo Mask Alignment System Using Dual CCDs with an XXY Stage

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Chih-Jer Lin

2016-02-01

Full Text Available Mask alignment of photolithography technology is used in many applications, such as micro electro mechanical systems’ semiconductor process, printed circuits board, and flat panel display. As the dimensions of the product are getting smaller and smaller, the automatic mask alignment of photolithography is becoming more and more important. The traditional stacked XY-Θz stage is heavy and it has cumulative flatness errors due to its stacked assembly mechanism. The XXY stage has smaller cumulative error due to its coplanar design and it can move faster than the traditional XY-Θz stage. However, the relationship between the XXY stage’s movement and the commands of the three motors is difficult to compute, because the movements of the three motors on the same plane are coupling. Therefore, an artificial neural network is studied to establish a nonlinear mapping from the desired position and orientation of the stage to three motors’ commands. Further, this paper proposes an image-servo automatic mask alignment system, which consists of a coplanar XXY stage, dual GIGA-E CCDs with lens and a programmable automatic controller (PAC. Before preforming the compensation, a self-developed visual-servo provides the positioning information which is obtained from the image processing and pattern recognition according to the specified fiducial marks. To obtain better precision, two methods including the center of gravity method and the generalize Hough Transformation are studied to correct the shift positioning error.

Vision Servo Motion Control and Error Analysis of a Coplanar XXY Stage for Image Alignment Motion

Directory of Open Access Journals (Sweden)

Hau-Wei Lee

2013-01-01

Full Text Available In recent years, as there is demand for smart mobile phones with touch panels, the alignment/compensation system of alignment stage with vision servo control has also increased. Due to the fact that the traditional stacked-type XYθ stage has cumulative errors of assembly and it is heavy, it has been gradually replaced by the coplanar stage characterized by three actuators on the same plane with three degrees of freedom. The simplest image alignment mode uses two cameras as the equipments for feedback control, and the work piece is placed on the working stage. The work piece is usually engraved/marked. After the cameras capture images and when the position of the mark in the camera is obtained by image processing, the mark can be moved to the designated position in the camera by moving the stage and using alignment algorithm. This study used a coplanar XXY stage with 1 μm positioning resolution. Due to the fact that the resolution of the camera is about 3.75 μm per pixel, thus a subpixel technology is used, and the linear and angular alignment repeatability of the alignment system can achieve 1 μm and 5 arcsec, respectively. The visual servo motion control for alignment motion is completed within 1 second using the coplanar XXY stage.

Development of BLDC Electric Motor Control System In Hydraulic Servo Drive Based on Variable Hydrostatic Transmission

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O. I. Tarasov

2014-01-01

Full Text Available Modern robotic systems require the use of servo drives. Owing to encoder and negative feedback these drives ensure highly accurate motion parameters. In case of autonomous systems drives must also have high power characteristics. Moreover, in most cases, it was impossible to select the motor so that the speed and torque on its shaft were in compliance with those of required by the actuator. To match these parameters different types of reducers are used. The article justifies and considers a selection criterion of the gear ratios for such transmission. For clarity, there is an example of selecting a motor and a gear for above transmission, taking into account the proposed criterion. In addition, the article discusses the advantages of using hydrostatic transmission in the drive, which monitors the angular position of the output level, in comparison with a mechanical gearbox. Due to the fact that, at the moment, BLDC motors have the best power characteristics, such a servo drive requires a special control system that will take into account the features of variable hydrostatic transmission and electric BLDC motor. Therefore, the paper proposes a structure of such a system and set out the principles of its construction. Various embodiments of sensor types that may be used in this system and their installation scheme explained.

Improved servo-controlled inertial clock for laboratory tests of general relativity

International Nuclear Information System (INIS)

Leyh, C.H.

1984-01-01

An inertial clock, consisting of a protected macroscopic rotor as the time base, was developed and tested preliminarily and partially by Cheung. This research offers considerable refinement of the equipment and the operating software, and includes serious testing of the experimental behavior. The inertial clock uses magnetic suspension to levitate a capped hollow cylindrical rotor (called the shroud rotor) within a vacuum chamber. A second rotor (called the proof rotor) is magnetically suspended within the shroud rotor. The shroud rotor is caused to corotate precisely with the rotating proof rotor by a microcomputer-controlled eddy current drive feedback servo loop. This produces a drag-free environment for the proof rotor which becomes the inertial timekeeper. In this way corotation effectively eliminates the residual gas drag on the proof rotor and the magnetic suspension bearing reduces bearing drag

Predictive IP controller for robust position control of linear servo system.

Science.gov (United States)

Lu, Shaowu; Zhou, Fengxing; Ma, Yajie; Tang, Xiaoqi

2016-07-01

Position control is a typical application of linear servo system. In this paper, to reduce the system overshoot, an integral plus proportional (IP) controller is used in the position control implementation. To further improve the control performance, a gain-tuning IP controller based on a generalized predictive control (GPC) law is proposed. Firstly, to represent the dynamics of the position loop, a second-order linear model is used and its model parameters are estimated on-line by using a recursive least squares method. Secondly, based on the GPC law, an optimal control sequence is obtained by using receding horizon, then directly supplies the IP controller with the corresponding control parameters in the real operations. Finally, simulation and experimental results are presented to show the efficiency of proposed scheme. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Adaptive integral robust control and application to electromechanical servo systems.

Science.gov (United States)

Deng, Wenxiang; Yao, Jianyong

2017-03-01

This paper proposes a continuous adaptive integral robust control with robust integral of the sign of the error (RISE) feedback for a class of uncertain nonlinear systems, in which the RISE feedback gain is adapted online to ensure the robustness against disturbances without the prior bound knowledge of the additive disturbances. In addition, an adaptive compensation integrated with the proposed adaptive RISE feedback term is also constructed to further reduce design conservatism when the system also exists parametric uncertainties. Lyapunov analysis reveals the proposed controllers could guarantee the tracking errors are asymptotically converging to zero with continuous control efforts. To illustrate the high performance nature of the developed controllers, numerical simulations are provided. At the end, an application case of an actual electromechanical servo system driven by motor is also studied, with some specific design consideration, and comparative experimental results are obtained to verify the effectiveness of the proposed controllers. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

All-Coefficient Adaptive Control of Dual-Motor Driving Servo System

Directory of Open Access Journals (Sweden)

Zhao Haibo

2017-01-01

Full Text Available Backlash nonlinearity and friction nonlinearity exist in dual-motor driving servo system, which reducing system response speed, steady accuracy and anti-interference ability. In order to diminish the adverse effects of backlash and friction nonlinearity to system, we proposed a new all-coefficient adaptive control method. Firstly, we introduced the dynamic model of backlash and friction nonlinearity respectively. Then on this basis, we established the characteristic model when backlash and friction nonlinearity coexist. We used recursive least square method for parameter estimation. Finally we designed the all-coefficient adaptive controller. On the basis of simplex all-coefficient adaptive controller, we designed a feedforward all-coefficient adaptive controller. The simulations of feedforward all-coefficient adaptive control and simplex all-coefficient adaptive control were compared. The results show that the former has quicker response speed, higher steady accuracy, stronger anti-interference performance and better robustness, which validating the efficacy of the proposed control strategy.

Teología y experiencia estética: el lugar de la imagen frente a la noción de Revelación de Martín Lutero y Juan Calvino

OpenAIRE

Luna-Vinueza, David Ricardo

2017-01-01

Resumen Este trabajo pretende argumentar que la concepción luterana y calvinista de la Revelación hace innecesario pensar la imagen como el lugar de lo sagrado. El postulado luterano de la justificación por la fe y el postulado calvinista de la doble predestinación descansan en una forma muy particular de entender la Revelación, que escinde al ser humano en dos dimensiones radicalmente diferentes: la espiritual y la corporal. Esa escisión tiene, a su vez, una distinción gemela: la separación ...

Hankel Matrix Correlation Function-Based Subspace Identification Method for UAV Servo System

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Minghong She

2018-01-01

Full Text Available For the identification problem of closed-loop subspace model, we propose a zero space projection method based on the estimation of correlation function to fill the block Hankel matrix of identification model by combining the linear algebra with geometry. By using the same projection of related data in time offset set and LQ decomposition, the multiplication operation of projection is achieved and dynamics estimation of the unknown equipment system model is obtained. Consequently, we have solved the problem of biased estimation caused when the open-loop subspace identification algorithm is applied to the closed-loop identification. A simulation example is given to show the effectiveness of the proposed approach. In final, the practicability of the identification algorithm is verified by hardware test of UAV servo system in real environment.

Autonomous Cargo Transport System for an Unmanned Aerial Vehicle, using Visual Servoing

Directory of Open Access Journals (Sweden)

Noah Kuntz

2009-12-01

Full Text Available This paper presents the design and testing of a system for autonomous tracking, pickup, and delivery of cargo via an unmanned helicopter. The tracking system uses a visual servoing algorithm and is tested using open loop velocity control of a six degree of freedom gantry system with a camera mounted via a pan-tilt unit on the end effecter. The pickup system uses vision to direct the camera pan tilt unit to track the target, and uses a hook attached to a second pan tilt unit to pick up the cargo. The ability of the pickup system to hook a target is tested by mounting it on the Systems Integrated Sensor Test Rig gantry system while recorded helicopter velocities are played back by the test rig.

Optimization of Smart Structure for Improving Servo Performance of Hard Disk Drive

Science.gov (United States)

Kajiwara, Itsuro; Takahashi, Masafumi; Arisaka, Toshihiro

Head positioning accuracy of the hard disk drive should be improved to meet today's increasing performance demands. Vibration suppression of the arm in the hard disk drive is very important to enhance the servo bandwidth of the head positioning system. In this study, smart structure technology is introduced into the hard disk drive to suppress the vibration of the head actuator. It has been expected that the smart structure technology will contribute to the development of small and light-weight mechatronics devices with the required performance. First, modeling of the system is conducted with finite element method and modal analysis. Next, the actuator location and the control system are simultaneously optimized using genetic algorithm. Vibration control effect with the proposed vibration control mechanisms has been evaluated by some simulations.

Panoramic optical-servoing for industrial inspection and repair

Science.gov (United States)

Sallinger, Christian; O'Leary, Paul; Retschnig, Alexander; Kammerhofer, Martin

2004-05-01

Recently specialized robots were introduced to perform the task of inspection and repair in large cylindrical structures such as ladles, melting furnaces and converters. This paper reports on the image processing system and optical servoing for one such a robot. A panoramic image of the vessels inner surface is produced by performing a coordinated robot motion and image acquisition. The level of projective distortion is minimized by acquiring a high density of images. Normalized phase correlation calculated via the 2D Fourier transform is used to calculate the shift between the single images. The narrow strips from the dense image map are then stitched together to build the panorama. The mapping between the panoramic image and the positioning of the robot is established during the stitching of the images. This enables optical feedback. The robots operator can locate a defect on the surface by selecting the area of the image. Calculation of the forward and inverse kinematics enable the robot to automatically move to the location on the surface requiring repair. Experimental results using a standard 6R industrial robot have shown the full functionality of the system concept. Finally, were test measurements carried out successfully, in a ladle at a temperature of 1100° C.

Pneumatic Rotary Actuator Position Servo System Based on ADE-PD Control

Directory of Open Access Journals (Sweden)

Yeming Zhang

2018-03-01

Full Text Available In order to accurately control the rotation position of a pneumatic rotary actuator, the flow state of the gas and the motion state of the pneumatic rotary actuator in the pneumatic rotary actuator position servo system are analyzed in this paper. The mathematical model of the system and the experiment platform are established after that. An Adaptive Differential Evolution (ADE algorithm which adaptively ameliorates the scaling factor and crossover probability in the process of individual evolution is proposed and applied to the parameter optimization of PD controller. The experimental platform is used to compare the controller with Differential Evolution (DE algorithm and NCD-PID controller. Finally, the characteristics of the system are tested by increasing the inertial load. The experimental results illustrate that system using ADE-PD control strategy has greater position precision and faster response than using DE-PD and NCD-PID strategies, and shows great robustness.

Smart rotor modeling aero-servo-elastic modeling of a smart rotor with adaptive trailing edge flaps

CERN Document Server

Bergami, Leonardo

2014-01-01

A smart rotor is a wind turbine rotor that, through a combination of sensors, control units and actuators actively reduces the variation of the aerodynamic loads it has to withstand. Smart rotors feature?promising load alleviation potential and might provide the technological breakthrough required by the next generation of large wind turbine rotors.The book presents the aero-servo-elastic model of a smart rotor with Adaptive Trailing Edge Flaps for active load alleviation and provides an insight on the rotor aerodynamic, structural and control modeling. A novel model for the unsteady aerodynam

DOS.

Science.gov (United States)

Traven, Bill

1988-01-01

Discusses using the DOS PATH command (for MS-DOS) to enable the microcomputer user to move from directory to directory on a hard drive. Lists the commands to be programed, gives examples, and explains the use of each. (MVL)

Electromagnetic servoing-a new tracking paradigm.

Science.gov (United States)

Reichl, Tobias; Gardiazabal, José; Navab, Nassir

2013-08-01

Electromagnetic (EM) tracking is highly relevant for many computer assisted interventions. This is in particular due to the fact that the scientific community has not yet developed a general solution for tracking of flexible instruments within the human body. Electromagnetic tracking solutions are highly attractive for minimally invasive procedures, since they do not require line of sight. However, a major problem with EM tracking solutions is that they do not provide uniform accuracy throughout the tracking volume and the desired, highest accuracy is often only achieved close to the center of tracking volume. In this paper, we present a solution to the tracking problem, by mounting an EM field generator onto a robot arm. Proposing a new tracking paradigm, we take advantage of the electromagnetic tracking to detect the sensor within a specific sub-volume, with known and optimal accuracy. We then use the more accurate and robust robot positioning for obtaining uniform accuracy throughout the tracking volume. Such an EM servoing methodology guarantees optimal and uniform accuracy, by allowing us to always keep the tracked sensor close to the center of the tracking volume. In this paper, both dynamic accuracy and accuracy distribution within the tracking volume are evaluated using optical tracking as ground truth. In repeated evaluations, the proposed method was able to reduce the overall error from 6.64±7.86 mm to a significantly improved accuracy of 3.83±6.43 mm. In addition, the combined system provides a larger tracking volume, which is only limited by the reach of the robot and not the much smaller tracking volume defined by the magnetic field generator.

Time-dependent rheoforging of A6061 aluminum alloy on a mechanical servo press and the effects of forming conditions on homogeneity of rheoforged samples

Directory of Open Access Journals (Sweden)

Meng Yi

2015-01-01

Full Text Available The solid and liquid phases in semisolid metal slurry exhibited different forming behaviours during deformation result in products with inhomogeneous quality. A6061 aluminum alloy was forged in the semisolid state on a mechanical servo press with the capability of multistage compression. To improve the homogeneity of rheoforged samples a time-dependent rheoforging strategy was designed. The distributions of the microstructure and mechanical properties the samples manufactured under various experimental conditions were investigated. The A6061 samples forged in the temperature range from 625 to 628 ∘C with a short holding time of 4 s and the upper die preheated to 300 ∘C exhibited a homogeneous microstructure and mechanical properties. The homogeneity of rheoforged samples resulted from the controllable free motion capability of the mechanical servo press and the adjustable fluidity and viscosity of the semisolid slurry.

Enhancing roll stability of heavy vehicle by LQR active anti-roll bar control using electronic servo-valve hydraulic actuators

Science.gov (United States)

Vu, Van Tan; Sename, Olivier; Dugard, Luc; Gaspar, Peter

2017-09-01

Rollover of heavy vehicle is an important road safety problem world-wide. Although rollovers are relatively rare events, they are usually deadly accidents when they occur. The roll stability loss is the main cause of rollover accidents in which heavy vehicles are involved. In order to improve the roll stability, most of modern heavy vehicles are equipped with passive anti-roll bars to reduce roll motion during cornering or riding on uneven roads. However these may be not sufficient to overcome critical situations. This paper introduces the active anti-roll bars made of four electronic servo-valve hydraulic actuators, which are modelled and integrated in a yaw-roll model of a single unit heavy vehicle. The control signal is the current entering the electronic servo-valve and the output is the force generated by the hydraulic actuator. The active control design is achieved solving a linear optimal control problem based on the linear quadratic regulator (LQR) approach. A comparison of several LQR controllers is provided to allow for tackling the considered multi-objective problems. Simulation results in frequency and time domains show that the use of two active anti-roll bars (front and rear axles) drastically improves the roll stability of the single unit heavy vehicle compared with the passive anti-roll bar.

A Visual Servoing-Based Method for ProCam Systems Calibration

Directory of Open Access Journals (Sweden)

Jeremie Mosnier

2013-10-01

Full Text Available Projector-camera systems are currently used in a wide field of applications, such as 3D reconstruction and augmented reality, and can provide accurate measurements, depending on the configuration and calibration. Frequently, the calibration task is divided into two steps: camera calibration followed by projector calibration. The latter still poses certain problems that are not easy to solve, such as the difficulty in obtaining a set of 2D–3D points to compute the projection matrix between the projector and the world. Existing methods are either not sufficiently accurate or not flexible. We propose an easy and automatic method to calibrate such systems that consists in projecting a calibration pattern and superimposing it automatically on a known printed pattern. The projected pattern is provided by a virtual camera observing a virtual pattern in an OpenGL model. The projector displays what the virtual camera visualizes. Thus, the projected pattern can be controlled and superimposed on the printed one with the aid of visual servoing. Our experimental results compare favorably with those of other methods considering both usability and accuracy.

The Improved SVM Multi Objects' Identification For the Uncalibrated Visual Servoing

Directory of Open Access Journals (Sweden)

Min Wang

2009-03-01

Full Text Available For the assembly of multi micro objects in micromanipulation, the first task is to identify multi micro parts. We present an improved support vector machine algorithm, which employs invariant moments based edge extraction to obtain feature attribute and then presents a heuristic attribute reduction algorithm based on rough set's discernibility matrix to obtain attribute reduction, with using support vector machine to identify and classify the targets. The visual servoing is the second task. For avoiding the complicated calibration of intrinsic parameter of camera, We apply an improved broyden's method to estimate the image jacobian matrix online, which employs chebyshev polynomial to construct a cost function to approximate the optimization value, obtaining a fast convergence for online estimation. Last, a two DOF visual controller based fuzzy adaptive PD control law for micro-manipulation is presented. The experiments of micro-assembly of micro parts in microscopes confirm that the proposed methods are effective and feasible.

The Improved SVM Multi Objects's Identification for the Uncalibrated Visual Servoing

Directory of Open Access Journals (Sweden)

Xiangjin Zeng

2009-03-01

Full Text Available For the assembly of multi micro objects in micromanipulation, the first task is to identify multi micro parts. We present an improved support vector machine algorithm, which employs invariant moments based edge extraction to obtain feature attribute and then presents a heuristic attribute reduction algorithm based on rough set's discernibility matrix to obtain attribute reduction, with using support vector machine to identify and classify the targets. The visual servoing is the second task. For avoiding the complicated calibration of intrinsic parameter of camera, We apply an improved broyden's method to estimate the image jacobian matrix online, which employs chebyshev polynomial to construct a cost function to approximate the optimization value, obtaining a fast convergence for online estimation. Last, a two DOF visual controller based fuzzy adaptive PD control law for micro-manipulation is presented. The experiments of micro-assembly of micro parts in microscopes confirm that the proposed methods are effective and feasible.

Geografia das religiões: temas sobre a experiência e o pensamento na ordem dos frades menores capuchinhos = Geography of religious: issues about experience and thoughts of Capuchin Minor Friars Order

Directory of Open Access Journals (Sweden)

Becker, Elsbeth Lisa S.

2014-01-01

Full Text Available Este artigo apresenta temas sobre a experiência e o pensamento na Ordem dos Frades Menores Capuchinhos, que evidenciam a riqueza da perspectiva cultural da Geografia, sua espacialização, sua presença social e espiritual em diferentes fatos históricos. Visa-se a conhecer e a descrever a Ordem dos Frades Menores Capuchinhos, com ênfase à sua presença no estado do Rio Grande do Sul, Brasil, descrevendo atitudes, valores, entre outros aspectos, vinculados ao sentido e aos símbolos espiritualizados deste clero. Identificou-se o contexto da imigração italiana, no século XIX, e a con- sequente inserção dessa Ordem no Rio Grande do Sul como ponto de partida. A metodologia consistiu em uma análise documental, em textos de comentadores da filosofia franciscana e de entrevistas realizadas com oito frades Capuchinhos que pertencem à Província Sagrado Coração de Jesus. O artigo, pela complexidade do tema, não pode tratar detalhadamente da descrição da Ordem e dos símbolos em sua profundidade espiritual. Apenas destacou-se a abrangência geográfica dessa Ordem no Estado gaúcho e no Brasil e, também, nos países latino-americanos como Haiti e República Dominicana e evidenciou-se a vida religiosa consagrada, pela sua natureza, inserida na Igreja, contribuindo com sua presença e missão para o bem do povo de Deus. Constatou-se que o simbolismo franciscano está presente na atual sociedade, mesmo que esta não perceba, principalmente, difundido através do presépio e do Tau; e que os votos e a saudação de “Paz e Bem” apresentam maiores significados para aqueles que praticam essa filosofia de vida

Information literacy: um indicador de competência para a formação permanente de professores na sociedade do conhecimento/Information literacy: a indicator of competence for the continous teachers education in the knowledge society

Directory of Open Access Journals (Sweden)

Regina Célia Baptista Belluzzo

2004-01-01

Full Text Available Apresenta-se estudo e pesquisa desenvolvido com alunos de cursos de graduação em Pedagogia e Especialização em Formação de Professores, na Universidade do Sagrado Coração, de Bauru,SP, Brasil com aplicação de conceitos e princípios de aprendizagem significativa de Ausubel, de mapas conceituais e de Information Literacy ou competência em informação, na forma de aplicação de guia de pesquisa e de diagrama como organizador cognitivo, especialmente construídos. Os resultados indicaram uma maior agregação de valor à informação e a melhoria da qualidade de práticas pedagógicas, ampliando as possibilidades de exploração dos sujeitos em função de seus estilos cognitivos, podendo-se recomendar a sua incorporação como mais um recurso em ambientes hipertextuais educacionais. This paper presents a research had as with scholars of Psychology graduated courses and school teachers postgraduate at the Universidade do Sagrado Coração (USC-Bauru-SPBrazil with application of the conceptual and theoretical principles about the Ausubel’s significative apprenticement, through the construction of the conceptual maps and information literacy, presented in form of guidelines and diagram how cognitive organizer. The results show that there exists a favorable attitude regarding for information and quality pedagogical and didactical practices and the studys’ resulting material could be included in the hipertextual educacional environmentals.

A Simulation Model of Focus and Radial Servos in Compact Disc Players with Disc Surface Defects

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

2004-01-01

Compact Disc players have been on the market in more than two decades.As a consequence most of the control servo problems have been solved. A large remaining problem to solve is the handling of Compact Discs with severe surface defects like scratches and fingerprints. This paper introduces a method...... for making the design of controllers handling surface defects easier. A simulation model of Compact Disc players playing discs with surface defects is presented. The main novel element in the model is a model of the surface defects. That model is based on data from discs with surface defects. This model...

Application to the field of medical and welfare with fluid power; Fluid power servo no iryo fukushi bun`ya eno oyo

Energy Technology Data Exchange (ETDEWEB)

Hayakawa, Y. [Nara Technical Coll., Nara (Japan)

1999-05-15

Reported herein are medical and welfare apparatuses activated by fluid power servos. Reference is also made to equipment now undergoing research and development. Numerous fluid power-driven welfare and caring apparatuses have been developed, some of which are named below. In an externally powered prosthetic leg, a rocking type hydraulic servo actuator is attached on the knee section. In this device, switching is performed between an active operation in which much torque is required for instance going up and down a stairway and a passive operation in which less torque is required for instance walking on a flat place, this for increased energy efficiency. In an externally powered orthosisis, an exoskeleton is installed on the lower extremities of a patient suffering from the paralysis of both legs, and enables physical exercises for rehabilitation. Such devices are controlled by one of the two methods, the master-slave method or the manual method. Devices for the transfer of patients include an in-home bathing assist system, powered assist suit for caring, powered assist chair, movable lift for transfer, pneumatic Rubbertuator-driven rehabilitation equipment, walk training device, and wavy motion pneumatic vibrator. (NEDO)

Miniaturization of a Quasi-Servo Valve and Its Application to Positon Control of a Rubber Artificial Muscle with Built-in Sensor

Directory of Open Access Journals (Sweden)

Moriwake Yoshinori

2016-01-01

Full Text Available Nowadays, the care and welfare pneumatic devices to support a nursing care and a self-reliance of the elderly and the disabled are actively researched and developed by many researchers. These wearable devices require many actuators and control valves for multi degrees of freedom. The total weight and volume of the wearable devices increases according to the degree of freedom. Our final goal is to develop a compact wearable actuator with built-in sensor, controller and control valve and to apply it to a wearable assisted device. In our previous study, a small-sized quasi-servo valve which consists of two on/off control valves and an embedded controller was developed. In this study, the quasi-servo valve composing of much smaller-sized (40% in mass, 42% in volume on/off valves is proposed and tested. In addition, the rubber artificial muscle with an ultrasonic sensor as a built-in displacement sensor is proposed and a position control of the muscle is carried out using the tested tiny valve and built-in sensor. As a result, it was confirmed that the position control of the muscle can be realized using the tested ultrasonic sensor.

Steady flow torques in a servo motor operated rotary directional control valve

International Nuclear Information System (INIS)

Wang, He; Gong, Guofang; Zhou, Hongbin; Wang, Wei

2016-01-01

Highlights: • A novel servo motor operated rotary directional control valve is proposed. • Steady flow torque is a crucial issue that affects rotary valve performance. • Steady flow torque is analyzed on the aspects of theory, simulation and experiment. • Change law of the steady flow torque with spool rotation angle is explored. • Effect of pressure drop and flow rate on the steady flow torque is studied. - Abstract: In this paper, a servo motor operated rotary directional control valve is proposed, and a systematic analysis of steady flow torques in this valve is provided by theoretical calculation, CFD simulation and experimental test. In the analysis, spool rotation angle corresponding to the maximum orifice opening is tagged as 0°. Over a complete change cycle of the orifice, the range of spool rotation angle is symmetric about 0°. The results show that the direction of steady flow torques in this valve is always the direction of orifice closing. The steady flow torques serve as resistances to the spool rotation when the orifice opening increases, while impetuses to the spool rotation when the orifice opening decreases. At a certain pressure drop or flow rate, steady flow torques are approximately equal and opposite when at spool rotation angles which are symmetric about 0°. When the spool rotates from 0°, at a certain pressure drop, their values increase first then decrease with the spool rotation and reach their maximum values at an angle corresponding to about 1/2 of the maximum orifice opening, and at a certain flow rate, their values increase with the spool rotation. The steady flow torques in this valve are the sums of those in the meter-in and meter-out valve chambers. At a certain spool rotation angle, steady flow torques in the meter-in and meter-out valve chambers are approximately proportional to the pressure drop and the second power of the flow rate through the orifice. Theoretical calculation and CFD simulation can be validated by

A Design Method for Fault Reconfiguration and Fault-Tolerant Control of a Servo Motor

Directory of Open Access Journals (Sweden)

Jing He

2013-01-01

Full Text Available A design scheme that integrates fault reconfiguration and fault-tolerant position control is proposed for a nonlinear servo system with friction. Analysis of the non-linear friction torque and fault in the system is used to guide design of a sliding mode position controller. A sliding mode observer is designed to achieve fault reconfiguration based on the equivalence principle. Thus, active fault-tolerant position control of the system can be realized. A real-time simulation experiment is performed on a hardware-in-loop simulation platform. The results show that the system reconfigures well for both incipient and abrupt faults. Under the fault-tolerant control mechanism, the output signal for the system position can rapidly track given values without being influenced by faults.

Identification and real-time position control of a servo-hydraulic rotary actuator by means of a neurobiologically motivated algorithm.

Science.gov (United States)

Sadeghieh, Ali; Sazgar, Hadi; Goodarzi, Kamyar; Lucas, Caro

2012-01-01

This paper presents a new intelligent approach for adaptive control of a nonlinear dynamic system. A modified version of the brain emotional learning based intelligent controller (BELBIC), a bio-inspired algorithm based upon a computational model of emotional learning which occurs in the amygdala, is utilized for position controlling a real laboratorial rotary electro-hydraulic servo (EHS) system. EHS systems are known to be nonlinear and non-smooth due to many factors such as leakage, friction, hysteresis, null shift, saturation, dead zone, and especially fluid flow expression through the servo valve. The large value of these factors can easily influence the control performance in the presence of a poor design. In this paper, a mathematical model of the EHS system is derived, and then the parameters of the model are identified using the recursive least squares method. In the next step, a BELBIC is designed based on this dynamic model and utilized to control the real laboratorial EHS system. To prove the effectiveness of the modified BELBIC's online learning ability in reducing the overall tracking error, results have been compared to those obtained from an optimal PID controller, an auto-tuned fuzzy PI controller (ATFPIC), and a neural network predictive controller (NNPC) under similar circumstances. The results demonstrate not only excellent improvement in control action, but also less energy consumption. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

A switched energy saving position controller for variable-pressure electro-hydraulic servo systems.

Science.gov (United States)

Tivay, Ali; Zareinejad, Mohammad; Rezaei, S Mehdi; Baghestan, Keivan

2014-07-01

The electro-hydraulic servo system (EHSS) demonstrates a relatively low level of efficiency compared to other available actuation methods. The objective of this paper is to increase this efficiency by introducing a variable supply pressure into the system and controlling this pressure during the task of position tracking. For this purpose, an EHSS structure with controllable supply pressure is proposed and its dynamic model is derived from the basic laws of physics. A switching control structure is then proposed to control both the supply pressure and the cylinder position at the same time, in a way that reduces the overall energy consumption of the system. The stability of the proposed switching control system is guaranteed by proof, and its performance is verified by experimental testing. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Towards an Aero-Propulso-Servo-Elasticity Analysis of a Commercial Supersonic Transport

Science.gov (United States)

Connolly, Joseph W.; Kopasakis, George; Chwalowski, Pawel; Sanetrik, Mark D.; Carlson, Jan-Renee; Silva, Walt A.; McNamara, Jack

2016-01-01

This paper covers the development of an aero-propulso-servo-elastic (APSE) model using computational fluid dynamics (CFD) and linear structural deformations. The APSE model provides the integration of the following two previously developed nonlinear dynamic simulations: a variable cycle turbofan engine and an elastic supersonic commercial transport vehicle. The primary focus of this study is to provide a means to include relevant dynamics of a turbomachinery propulsion system into the aeroelastic studies conducted during a vehicle design, which have historically neglected propulsion effects. A high fidelity CFD tool is used here for the integration platform. The elastic vehicle neglecting the propulsion system serves as a comparison of traditional approaches to the APSE results. An overview of the methodology is presented for integrating the propulsion system and elastic vehicle. Static aeroelastic analysis comparisons between the traditional and developed APSE models for a wing tip detection indicate that the propulsion system impact on the vehicle elastic response could increase the detection by approximately ten percent.

Position Based Visual Servoing control of a Wheelchair Mounter Robotic Arm using Parallel Tracking and Mapping of task objects

Directory of Open Access Journals (Sweden)

Alessandro Palla

2017-05-01

Full Text Available In the last few years power wheelchairs have been becoming the only device able to provide autonomy and independence to people with motor skill impairments. In particular, many power wheelchairs feature robotic arms for gesture emulation, like the interaction with objects. However, complex robotic arms often require a joystic to be controlled; this feature make the arm hard to be controlled by impaired users. Paradoxically, if the user were able to proficiently control such devices, he would not need them. For that reason, this paper presents a highly autonomous robotic arm, designed in order to minimize the effort necessary for the control of the arm. In order to do that, the arm feature an easy to use human - machine interface and is controlled by Computer Vison algorithm, implementing a Position Based Visual Servoing (PBVS control. It was realized by extracting features by the camera and fusing them with the distance from the target, obtained by a proximity sensor. The Parallel Tracking and Mapping (PTAM algorithm was used to find the 3D position of the task object in the camera reference system. The visual servoing algorithm was implemented in an embedded platform, in real time. Each part of the control loop was developed in Robotic Operative System (ROS Environment, which allows to implement the previous algorithms as different nodes. Theoretical analysis, simulations and in system measurements proved the effectiveness of the proposed solution.

Development and performance tests of the bridge-transported servo manipulator system for remote maintenance jobs in a hot cell

International Nuclear Information System (INIS)

Jin, Jae Hyun; Park, Byung Suk; Ko, Byung Seung; Yoon, Ji Sup; Jung, Ki Jung

2005-01-01

In this paper, a prototype of the Bridge-Transported Servo Manipulator (BTSM) system introduced, which has been developed to do operation and maintenance jobs remotely in a hot cell. The system consists of a telescopic transporter, a slave arm, a master arm, and a control system. Several tests such as a positional tracking, a weight handling, reliability, and operability have been performed and test results are presented. Based on the test results, an upgraded system which will be used during demonstrations of the advanced spent fuel conditioning process (ACP) has been designed.

Disturbance torque rejection properties of the NASA/JPL 70-meter antenna axis servos

Science.gov (United States)

Hill, R. E.

1989-01-01

Analytic methods for evaluating pointing errors caused by external disturbance torques are developed and applied to determine the effects of representative values of wind and friction torque. The expressions relating pointing errors to disturbance torques are shown to be strongly dependent upon the state estimator parameters, as well as upon the state feedback gain and the flow versus pressure characteristics of the hydraulic system. Under certain conditions, when control is derived from an uncorrected estimate of integral position error, the desired type 2 servo properties are not realized and finite steady-state position errors result. Methods for reducing these errors to negligible proportions through the proper selection of control gain and estimator correction parameters are demonstrated. The steady-state error produced by a disturbance torque is found to be directly proportional to the hydraulic internal leakage. This property can be exploited to provide a convenient method of determining system leakage from field measurements of estimator error, axis rate, and hydraulic differential pressure.

Role of pressure in angiotensin II-induced renal injury: chronic servo-control of renal perfusion pressure in rats.

Science.gov (United States)

Mori, Takefumi; Cowley, Allen W

2004-04-01

Renal perfusion pressure was servo-controlled chronically in rats to quantify the relative contribution of elevated arterial pressure versus angiotensin II (Ang II) on the induction of renal injury in Ang II-induced hypertension. Sprague-Dawley rats fed a 4% salt diet were administered Ang II for 14 days (25 ng/kg per minute IV; saline only for sham rats), and the renal perfusion pressure to the left kidney was continuously servo-controlled to maintain a normal pressure in that kidney throughout the period of hypertension. An aortic occluder was implanted around the aorta between the two renal arteries and carotid and femoral arterial pressure were measured continuously throughout the experiment to determine uncontrolled and controlled renal perfusion pressure, respectively. Renal perfusion pressure of uncontrolled, controlled, and sham kidneys over the period of Ang II or saline infusion averaged 152.6+/-7.0, 117.4+/-3.5, and 110.7+/-2.2 mm Hg, respectively. The high-pressure uncontrolled kidneys exhibited tubular necrosis and interstitial fibrosis, especially prominent in the outer medullary region. Regional glomerular sclerosis and interlobular artery injury were also pronounced. Controlled kidneys were significantly protected from interlobular artery injury, juxtamedullary glomeruli injury, tubular necrosis, and interstitial fibrosis as determined by comparing the level of injury. Glomerular injury was not prevented in the outer cortex. Transforming growth factor (TGF)-beta and active NF-kappaB proteins determined by immunohistochemistry were colocalized in the uncontrolled kidney in regions of interstitial fibrosis. We conclude that the preferential juxtamedullary injury found in Ang II hypertension is largely induced by pressure and is probably mediated through the TGF-beta and NF-kappaB pathway.

Os organismos geneticamente modificados e a rotulagem dos alimentos - uma análise a partir dos direitos dos consumidores

Directory of Open Access Journals (Sweden)

Marcello Vitor Rocha Cota

2015-11-01

Full Text Available Ao longo do presente trabalho serão analisados os organismos geneticamente modificados (OGMs frente aos riscos à saúde alimentar e ao meio ambiente, sobretudo o princípio da precaução e a rotulagem dos produtos. A partir de uma dimensão comparativa de três realidades distintas, isto é, a estadunidense, a europeia, com ênfase mercado ao português, e a brasileira – sob um prisma ambiental, a rotulagem dos produtos será confrontada com os direitos dos consumidores, embora em determinadas ocasiões, diante da inexistência de informações adequadas e claras dos produtos, que estão sendo ofertados e consumidos, os consumidores não sabem o que estão consumindo.

Autonomia profissional dos professores

OpenAIRE

Guerra, Teresa P.; Veiga, Feliciano

2007-01-01

Este estudo pretendeu analisar as representações dos professores acerca da sua autonomia em contexto escolar, com recurso a uma amostra de 203 professores de ambos os sexos, pertencentes a escolas dos distritos de Lisboa, Setúbal, Leiria e Aveiro. Utilizou-se a Escala de Autonomia Profissional dos Professores (EAPP).

Religiosidade popular: Reisado em Balsas (MA, uma experiência do sagrado

Directory of Open Access Journals (Sweden)

Raimundo Rajobac

2011-03-01

Full Text Available

O trabalho tem como objetivo apresentar uma leitura do Reisado em Balsas (MA, a partir do que nos propõe o método da Fenomenologia da Religião. Procuraremos identificar no Reisado, em sua estrutura e forma de expressão, os elementos que justifiquem a dimensão religiosa do ser humano. Para uma melhor observação e descrição desse fenômeno, e de sua forma de expressão, servirmo-nos de uma pesquisa de campo realizada em dezembro de 2005 a janeiro de 2006, o qual comporta os preparativos e realização da Festa dos Santos Reis, na região de Balsas (MA.

PID-Controller Tuning Optimization with Genetic Algorithms in Servo Systems

Directory of Open Access Journals (Sweden)

Arturo Y. Jaen-Cuellar

2013-09-01

Full Text Available Performance improvement is the main goal of the study of PID control and much research has been conducted for this purpose. The PID filter is implemented in almost all industrial processes because of its well-known beneficial features. In general, the whole system's performance strongly depends on the controller's efficiency and hence the tuning process plays a key role in the system's behaviour. In this work, the servo systems will be analysed, specifically the positioning control systems. Among the existent tuning methods, the Gain-Phase Margin method based on Frequency Response analysis is the most adequate for controller tuning in positioning control systems. Nevertheless, this method can be improved by integrating an optimization technique. The novelty of this work is the development of a new methodology for PID control tuning by coupling the Gain-Phase Margin method with the Genetic Algorithms in which the micro-population concept and adaptive mutation probability are applied. Simulations using a positioning system model in MATLAB and experimental tests in two CNC machines and an industrial robot are carried out in order to show the effectiveness of the proposal. The obtained results are compared with both the classical Gain-Phase Margin tuning and with a recent PID controller optimization using Genetic Algorithms based on real codification. The three methodologies are implemented using software.

Evaluation of the Argonne National Laboratory servo-controlled calorimeter system

International Nuclear Information System (INIS)

Foster, L.A.

1997-01-01

The control system of a replacement mode, twin-bridge, water-bath calorimeter originally built by Mound EG ampersand G Applied Technologies was modified by Argonne National Laboratory. The calorimeter was upgraded with a PC-based computer control and data acquisition system. The system was redesigned to operate in a servo-control mode, and a preheater was constructed to allow pre-equilibration of samples. The instrument was sent to the Plutonium Facility at Los Alamos National Laboratory for testing and evaluation of its performance in the field using heat source standards and plutonium process materials. The important parameters for calorimeter operation necessary to satisfy the nuclear materials control and accountability requirements of the Plutonium Facility were evaluated over a period of several months. These parameters include calorimeter stability, measurement precision and accuracy, and average measurement time. The observed measurement precision and accuracy were found to be acceptable for most accountability measurements, although they were slightly larger than the values for calorimeters in routine use at the Plutonium Facility. Average measurement times were significantly shorter than measurement times for identical items in the Plutonium Facility calorimeters. Unexplained shifts in the baseline measurements were observed on numerous occasions. These shifts could lead to substantial measurement errors if they are not very carefully monitored by the operating facility. Detailed results of the experimental evaluation are presented in this report

Propulsion System Dynamic Modeling for the NASA Supersonic Concept Vehicle: AeroPropulsoServoElasticity

Science.gov (United States)

Kopasakis, George; Connolly, Joseph; Seidel, Jonathan

2014-01-01

A summary of the propulsion system modeling under NASA's High Speed Project (HSP) AeroPropulsoServoElasticity (APSE) task is provided with a focus on the propulsion system for the low-boom supersonic configuration developed by Lockheed Martin and referred to as the N+2 configuration. This summary includes details on the effort to date to develop computational models for the various propulsion system components. The objective of this paper is to summarize the model development effort in this task, while providing more detail in the modeling areas that have not been previously published. The purpose of the propulsion system modeling and the overall APSE effort is to develop an integrated dynamic vehicle model to conduct appropriate unsteady analysis of supersonic vehicle performance. This integrated APSE system model concept includes the propulsion system model, and the vehicle structural-aerodynamics model. The development to date of such a preliminary integrated model will also be summarized in this report.propulsion system dynamics, the structural dynamics, and aerodynamics.

Adaptive GSA-based optimal tuning of PI controlled servo systems with reduced process parametric sensitivity, robust stability and controller robustness.

Science.gov (United States)

Precup, Radu-Emil; David, Radu-Codrut; Petriu, Emil M; Radac, Mircea-Bogdan; Preitl, Stefan

2014-11-01

This paper suggests a new generation of optimal PI controllers for a class of servo systems characterized by saturation and dead zone static nonlinearities and second-order models with an integral component. The objective functions are expressed as the integral of time multiplied by absolute error plus the weighted sum of the integrals of output sensitivity functions of the state sensitivity models with respect to two process parametric variations. The PI controller tuning conditions applied to a simplified linear process model involve a single design parameter specific to the extended symmetrical optimum (ESO) method which offers the desired tradeoff to several control system performance indices. An original back-calculation and tracking anti-windup scheme is proposed in order to prevent the integrator wind-up and to compensate for the dead zone nonlinearity of the process. The minimization of the objective functions is carried out in the framework of optimization problems with inequality constraints which guarantee the robust stability with respect to the process parametric variations and the controller robustness. An adaptive gravitational search algorithm (GSA) solves the optimization problems focused on the optimal tuning of the design parameter specific to the ESO method and of the anti-windup tracking gain. A tuning method for PI controllers is proposed as an efficient approach to the design of resilient control systems. The tuning method and the PI controllers are experimentally validated by the adaptive GSA-based tuning of PI controllers for the angular position control of a laboratory servo system.

Sinusoidal visuomotor tracking: intermittent servo-control or coupled oscillations?

Science.gov (United States)

Russell, D M; Sternad, D

2001-12-01

In visuomotor tasks that involve accuracy demands, small directional changes in the trajectories have been taken as evidence of feedback-based error corrections. In the present study variability, or intermittency, in visuomanual tracking of sinusoidal targets was investigated. Two lines of analyses were pursued: First, the hypothesis that humans fundamentally act as intermittent servo-controllers was re-examined, probing the question of whether discontinuities in the movement trajectory directly imply intermittent control. Second, an alternative hypothesis was evaluated: that rhythmic tracking movements are generated by entrainment between the oscillations of the target and the actor, such that intermittency expresses the degree of stability. In 2 experiments, participants (N = 6 in each experiment) swung 1 of 2 different hand-held pendulums, tracking a rhythmic target that oscillated at different frequencies with a constant amplitude. In 1 line of analyses, the authors tested the intermittency hypothesis by using the typical kinematic error measures and spectral analysis. In a 2nd line, they examined relative phase and its variability, following analyses of rhythmic interlimb coordination. The results showed that visually guided corrective processes play a role, especially for slow movements. Intermittency, assessed as frequency and power components of the movement trajectory, was found to change as a function of both target frequency and the manipulandum's inertia. Support for entrainment was found in conditions in which task frequency was identical to or higher than the effector's eigenfrequency. The results suggest that it is the symmetry between task and effector that determines which behavioral regime is dominant.

Modal space three-state feedback control for electro-hydraulic servo plane redundant driving mechanism with eccentric load decoupling.

Science.gov (United States)

Zhao, Jinsong; Wang, Zhipeng; Zhang, Chuanbi; Yang, Chifu; Bai, Wenjie; Zhao, Zining

2018-06-01

The shaking table based on electro-hydraulic servo parallel mechanism has the advantage of strong carrying capacity. However, the strong coupling caused by the eccentric load not only affects the degree of freedom space control precision, but also brings trouble to the system control. A novel decoupling control strategy is proposed, which is based on modal space to solve the coupling problem for parallel mechanism with eccentric load. The phenomenon of strong dynamic coupling among degree of freedom space is described by experiments, and its influence on control design is discussed. Considering the particularity of plane motion, the dynamic model is built by Lagrangian method to avoid complex calculations. The dynamic equations of the coupling physical space are transformed into the dynamic equations of the decoupling modal space by using the weighted orthogonality of the modal main mode with respect to mass matrix and stiffness matrix. In the modal space, the adjustments of the modal channels are independent of each other. Moreover, the paper discusses identical closed-loop dynamic characteristics of modal channels, which will realize decoupling for degree of freedom space, thus a modal space three-state feedback control is proposed to expand the frequency bandwidth of each modal channel for ensuring their near-identical responses in a larger frequency range. Experimental results show that the concept of modal space three-state feedback control proposed in this paper can effectively reduce the strong coupling problem of degree of freedom space channels, which verify the effectiveness of the proposed model space state feedback control strategy for improving the control performance of the electro-hydraulic servo plane redundant driving mechanism. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

An energy-saving nonlinear position control strategy for electro-hydraulic servo systems.

Science.gov (United States)

Baghestan, Keivan; Rezaei, Seyed Mehdi; Talebi, Heidar Ali; Zareinejad, Mohammad

2015-11-01

The electro-hydraulic servo system (EHSS) demonstrates numerous advantages in size and performance compared to other actuation methods. Oftentimes, its utilization in industrial and machinery settings is limited by its inferior efficiency. In this paper, a nonlinear backstepping control algorithm with an energy-saving approach is proposed for position control in the EHSS. To achieve improved efficiency, two control valves including a proportional directional valve (PDV) and a proportional relief valve (PRV) are used to achieve the control objectives. To design the control algorithm, the state space model equations of the system are transformed to their normal form and the control law through the PDV is designed using a backstepping approach for position tracking. Then, another nonlinear set of laws is derived to achieve energy-saving through the PRV input. This control design method, based on the normal form representation, imposes internal dynamics on the closed-loop system. The stability of the internal dynamics is analyzed in special cases of operation. Experimental results verify that both tracking and energy-saving objectives are satisfied for the closed-loop system. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

A versatile hydraulically operated respiratory servo system for ventilation and lung function testing.

Science.gov (United States)

Meyer, M; Slama, H

1983-09-01

A description is given of the design and performance of a microcomputer-controlled respiratory servo system that incorporates the characteristics of a mechanical ventilator and also allows the performance of a multitude of test procedures required for assessment of pulmonary function in paralyzed animals. The device consists of a hydraulically operated cylinder-piston assembly and solenoid valves that direct inspiratory and expiratory gas flow and also enable switching to different test gas sources. The system operates as a volume-flow-preset ventilator but may be switched to other operational cycling modes. Gas flow rates may be constant or variable. The system operates as an assister-controller and, combined with a gas analyzer, can function as a "demand" ventilator allowing for set-point control of end-tidal PCO2 and PO2. Complex breathing maneuvers for a variety of single- and multiple-breath lung function tests are automatically performed. Because of the flexibility in selection and timing of respiratory parameters, the system is particularly suitable for respiratory gas studies.

Adaptive Hybrid Visual Servo Regulation of Mobile Robots Based on Fast Homography Decomposition

Directory of Open Access Journals (Sweden)

Chunfu Wu

2015-01-01

Full Text Available For the monocular camera-based mobile robot system, an adaptive hybrid visual servo regulation algorithm which is based on a fast homography decomposition method is proposed to drive the mobile robot to its desired position and orientation, even when object’s imaging depth and camera’s position extrinsic parameters are unknown. Firstly, the homography’s particular properties caused by mobile robot’s 2-DOF motion are taken into account to induce a fast homography decomposition method. Secondly, the homography matrix and the extracted orientation error, incorporated with the desired view’s single feature point, are utilized to form an error vector and its open-loop error function. Finally, Lyapunov-based techniques are exploited to construct an adaptive regulation control law, followed by the experimental verification. The experimental results show that the proposed fast homography decomposition method is not only simple and efficient, but also highly precise. Meanwhile, the designed control law can well enable mobile robot position and orientation regulation despite the lack of depth information and camera’s position extrinsic parameters.

Território e Rede da União do Vegetal

OpenAIRE

Morales Arteaga, Pamela Elizabeth

2016-01-01

Esta pesquisa trata do território e das redes geográficas da religião ayahusaqueira União do Vegetal, em Brasília. Busca-se interpretar os objetivos da pesquisa que foram; a construção do território da União do Vegetal, diferençando elementos relevantes do território; debatendo a hierarquização do grupo na sua atuação territorial e relacionando as percepções dos adeptos com suas práticas territoriais em rede. As hipóteses que nortearam o trabalho foram; A construção do território sagrado da U...

A discrete time-varying internal model-based approach for high precision tracking of a multi-axis servo gantry.

Science.gov (United States)

Zhang, Zhen; Yan, Peng; Jiang, Huan; Ye, Peiqing

2014-09-01

In this paper, we consider the discrete time-varying internal model-based control design for high precision tracking of complicated reference trajectories generated by time-varying systems. Based on a novel parallel time-varying internal model structure, asymptotic tracking conditions for the design of internal model units are developed, and a low order robust time-varying stabilizer is further synthesized. In a discrete time setting, the high precision tracking control architecture is deployed on a Voice Coil Motor (VCM) actuated servo gantry system, where numerical simulations and real time experimental results are provided, achieving the tracking errors around 3.5‰ for frequency-varying signals. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Modelos para leigas e religiosas: os livros do pe. Júlio Maria De Lombaerde (1878-1944

Directory of Open Access Journals (Sweden)

Nadia Maria Guariza

2016-12-01

Full Text Available O artigo analisa alguns livros do pe. Júlio Maria De Lombaerde, missionário belga que veio ao Brasil em 1902 e, desenvolveu parte dos seus trabalhos na cidade de Manhumirim (MG até a sua morte em 1944. O padre Júlio Maria escreveu mais de 80 livros, entre estes livros optou-se em investigar os que tratam do marianismo, da Sagrada Família e da vida de religiosas. A finalidade é refletir sobre os papéis femininos nos quadros da Igreja Católica nas primeiras décadas do século XX, tanto das leigas quanto das religiosas. Para tanto, entende-se que as representações sobre o feminino estavam ancoradas na divisão binária dos gêneros, reforçando hierarquias entre homens e mulheres, bem como na concepção de superioridade do sagrado em relação ao profano, estabelecendo assim, hierarquias, também, entre religiosas e leigas.

Use of servo controlled weld head for end closure welding

Energy Technology Data Exchange (ETDEWEB)

Pathak, S.K.; Setty, D.S.; Rameswara Rao, A.; Hemantha Rao, G.V.S.; Jayaraj, R.N. [Nuclear Fuel Complex, Dept. of Atomic Energy, Hyderabad (India)

2010-07-01

In the PHWR fuel fabrication line resistance welding processes are used for joining various zirconium based alloy components to fuel tube of similar material. The quality requirement of these welding processes is very stringent and has to meet all the product requirements. At present these welding processes are being carried out by using standard resistance welding machines. In the resistance welding process in addition to current and time, force is one of the critical and important parameter, which influences the weld quality. At present advanced feed back type fast response medium frequency weld controllers are being used. This has upslope/down slope, constant and repetitive weld pattern selection features makes this critical welding process more reliable. Compared to weld controllers, squeeze force application devices are limited and normally standard high response pneumatic cylinders are used in the welding process. With this type of devices the force is constant during welding process and cannot be varied during welding process as per the material deformation characteristics. Similarly due to non-availability of feed back systems in the squeeze force application systems restricts the accuracy and quality of the welding process. In the present paper the influence of squeeze force pattern on the weld quality using advanced feed back type servo based force control system was studied. Different squeeze forces were used during pre and post weld heat periods along with constant force and compared with the weld quality. (author)

DOS cones along atomic chains

International Nuclear Information System (INIS)

Kwapiński, Tomasz

2017-01-01

The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green’s function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin–orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears. (paper)

DOS cones along atomic chains

Science.gov (United States)

Kwapiński, Tomasz

2017-03-01

The electron transport properties of a linear atomic chain are studied theoretically within the tight-binding Hamiltonian and the Green’s function method. Variations of the local density of states (DOS) along the chain are investigated. They are crucial in scanning tunnelling experiments and give important insight into the electron transport mechanism and charge distribution inside chains. It is found that depending on the chain parity the local DOS at the Fermi level can form cone-like structures (DOS cones) along the chain. The general condition for the local DOS oscillations is obtained and the linear behaviour of the local density function is confirmed analytically. DOS cones are characterized by a linear decay towards the chain which is in contrast to the propagation properties of charge density waves, end states and Friedel oscillations in one-dimensional systems. We find that DOS cones can appear due to non-resonant electron transport, the spin-orbit scattering or for chains fabricated on a substrate with localized electrons. It is also shown that for imperfect chains (e.g. with a reduced coupling strength between two neighboring sites) a diamond-like structure of the local DOS along the chain appears.

HAWC2 and BeamDyn: Comparison Between Beam Structural Models for Aero-Servo-Elastic Frameworks: Preprint

Energy Technology Data Exchange (ETDEWEB)

Pavese, Christian; Kim, Taeseong; Wang, Qi; Jonkman, Jason; Sprague, Michael A.

2016-08-01

This work presents a comparison of two beam codes for aero-servo-elastic frameworks: a new structural model for the aeroelastic code HAWC2 and a new nonlinear beam model, BeamDyn, for the aeroelastic modularization framework FAST v8. The main goal is to establish the suitability of the two approaches to model the structural behaviour of modern wind turbine blades in operation. Through a series of benchmarking structural cases of increasing complexity, the capability of the two codes to simulate highly nonlinear effects is investigated and analyzed. Results show that even though the geometrically exact beam theory can better model effects such as very large deflections, rotations, and structural couplings, an approach based on a multi-body formulation assembled through linear elements is capable of computing accurate solutions for typical nonlinear beam theory benchmarking cases.

Robust H(∞) positional control of 2-DOF robotic arm driven by electro-hydraulic servo system.

Science.gov (United States)

Guo, Qing; Yu, Tian; Jiang, Dan

2015-11-01

In this paper an H∞ positional feedback controller is developed to improve the robust performance under structural and parametric uncertainty disturbance in electro-hydraulic servo system (EHSS). The robust control model is described as the linear state-space equation by upper linear fractional transformation. According to the solution of H∞ sub-optimal control problem, the robust controller is designed and simplified to lower order linear model which is easily realized in EHSS. The simulation and experimental results can validate the robustness of this proposed method. The comparison result with PI control shows that the robust controller is suitable for this EHSS under the critical condition where the desired system bandwidth is higher and the external load of the hydraulic actuator is closed to its limited capability. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Sofrimento mental e agências religiosas como rede social de apoio: subsídios para a enfermagem Sufrimiento mental y agencias religiosas como red social de apoyo: soporte para la enfermería Mental suffering and religious agencies as a social support network: support for nursing

Directory of Open Access Journals (Sweden)

Amanda Márcia dos Santos Reinaldo

2012-09-01

Full Text Available O sofrimento mental já foi considerado divinatório, misterioso e sagrado em relação as suas manifestações. O sagrado, a fé e a religião são procurados pelo sofredor em busca de alento para o sofrimento causado pelo transtorno mental. O objetivo do estudo é compreender a inserção e a percepção dos membros da rede social de apoio que se forma nas agências religiosas em torno da pessoa em sofrimento mental. Trata-se de uma pesquisa de abordagem qualitativa, descritiva, exploratória. Foram entrevistados 42 membros de agências religiosas (católica, evangélica e espírita. A análise dos resultados aponta que a pessoa em sofrimento procura aceitação, acolhimento e sentimento de pertença diante de um mundo que nem sempre o compreende. Em resposta à sua procura encontra apoio, compreensão e alento. A complexidade do tema merece reflexão e revisão de conceitos que perpassam a realidade vivida pelo sujeito em sofrimento mental.El sufrimiento mental ya se consideró divinatorio, misterioso y sagrado respecto a sus manifestaciones. Independiente de la religión, la búsqueda por el sagrado, la fe y las agencias religiosas son procuradas por el sufridor en búsqueda de aliento para el sufrimiento que causa el trastorno mental. La finalidad del estudio es comprehender la inserción y la percepción de los miembros de la red social de apoyo que se forma en las agencias religiosas alrededor de la persona en sufrimiento mental. Se trata de una investigación de aproximación cualitativa, descriptiva y exploratoria, donde fueron entrevistados 42 miembros de agencias religiosas (católica, protestante y espírita. El análisis de los resultados indica que, en las agencias religiosas, el sujeto sufridor busca aceptación, acogimiento y sentimiento de pertenencia ante un mundo que ni siempre lo comprehende. En respuesta a su búsqueda encuentra apoyo, comprensión y aliento. La complexidad del tema merece reflexión y revisión de conceptos

Development of an interface for an ultrareliable fault-tolerant control system and an electronic servo-control unit

Science.gov (United States)

Shaver, Charles; Williamson, Michael

1986-01-01

The NASA Ames Research Center sponsors a research program for the investigation of Intelligent Flight Control Actuation systems. The use of artificial intelligence techniques in conjunction with algorithmic techniques for autonomous, decentralized fault management of flight-control actuation systems is explored under this program. The design, development, and operation of the interface for laboratory investigation of this program is documented. The interface, architecturally based on the Intel 8751 microcontroller, is an interrupt-driven system designed to receive a digital message from an ultrareliable fault-tolerant control system (UFTCS). The interface links the UFTCS to an electronic servo-control unit, which controls a set of hydraulic actuators. It was necessary to build a UFTCS emulator (also based on the Intel 8751) to provide signal sources for testing the equipment.

Application of Automatic Zooming and Autofocusing in Microassembly using Visual Servoing

International Nuclear Information System (INIS)

Jang, Kyung-Nam; Kim, Jong-Seog

2006-01-01

In recent years, many industrial products and their components are evolving toward miniaturization. To have more functionalities within less dimensional volume, they are usually made of various materials with different characteristics, and they are manufactured using incompatible manufacturing processes with complex geometrical shapes. For these reasons, the assembly technique for mating micro-parts so called microassembly has become important for advanced manufacturing and drawn extensive research interest. Currently, due to various difficulties arising from handling of extremely small size parts, manual assembly method has been widely used. Since this manual method is somehow timeconsuming and not productive enough, automation of micro-assembly has become an essential part for micro parts manufacturing. As an alternative, the vision sensor is widely used in microassembly. The vision sensor has a wide field of view, and it can obtain the wide range data with high speed without contact. In the previous research works, the orientation of the mating parts has not been considered for corrective motion, and, furthermore, the developed vision systems are not adaptive to accommodate various sizes of the mated parts to avoid such criticism, we propose a visual feedback system that accommodates micro parts of various sizes and parts arbitrarily oriented. In this paper, the system that employs adaptive zooming and auto focusing techniques during visual servoing is described

Design and motion control of bioinspired humanoid robot head from servo motors toward artificial muscles

Science.gov (United States)

Almubarak, Yara; Tadesse, Yonas

2017-04-01

The potential applications of humanoid robots in social environments, motivates researchers to design, and control biomimetic humanoid robots. Generally, people are more interested to interact with robots that have similar attributes and movements to humans. The head is one of most important part of any social robot. Currently, most humanoid heads use electrical motors, pneumatic actuators, and shape memory alloy (SMA) actuators for actuation. Electrical and pneumatic actuators take most of the space and would cause unsmooth motions. SMAs are expensive to use in humanoids. Recently, in many robotic projects, Twisted and Coiled Polymer (TCP) artificial muscles are used as linear actuators which take up little space compared to the motors. In this paper, we will demonstrate the designing process and motion control of a robotic head with TCP muscles. Servo motors and artificial muscles are used for actuating the head motion, which have been controlled by a cost efficient ARM Cortex-M7 based development board. A complete comparison between the two actuators is presented.

Propulsion System Dynamic Modeling of the NASA Supersonic Concept Vehicle for AeroPropulsoServoElasticity

Science.gov (United States)

Kopasakis, George; Connolly, Joseph W.; Seiel, Jonathan

2016-01-01

A summary of the propulsion system modeling under NASA's High Speed Project (HSP) AeroPropulsoServoElasticity (APSE) task is provided with a focus on the propulsion system for the low-boom supersonic configuration developed by Lockheed Martin and referred to as the N+2 configuration. This summary includes details on the effort to date to develop computational models for the various propulsion system components. The objective of this paper is to summarize the model development effort in this task, while providing more detail in the modeling areas that have not been previously published. The purpose of the propulsion system modeling and the overall APSE effort is to develop an integrated dynamic vehicle model to conduct appropriate unsteady analysis of supersonic vehicle performance. This integrated APSE system model concept includes the propulsion system model, and the vehicle structural aerodynamics model. The development to date of such a preliminary integrated model will also be summarized in this report

Indirect adaptive fuzzy wavelet neural network with self- recurrent consequent part for AC servo system.

Science.gov (United States)

Hou, Runmin; Wang, Li; Gao, Qiang; Hou, Yuanglong; Wang, Chao

2017-09-01

This paper proposes a novel indirect adaptive fuzzy wavelet neural network (IAFWNN) to control the nonlinearity, wide variations in loads, time-variation and uncertain disturbance of the ac servo system. In the proposed approach, the self-recurrent wavelet neural network (SRWNN) is employed to construct an adaptive self-recurrent consequent part for each fuzzy rule of TSK fuzzy model. For the IAFWNN controller, the online learning algorithm is based on back propagation (BP) algorithm. Moreover, an improved particle swarm optimization (IPSO) is used to adapt the learning rate. The aid of an adaptive SRWNN identifier offers the real-time gradient information to the adaptive fuzzy wavelet neural controller to overcome the impact of parameter variations, load disturbances and other uncertainties effectively, and has a good dynamic. The asymptotical stability of the system is guaranteed by using the Lyapunov method. The result of the simulation and the prototype test prove that the proposed are effective and suitable. Copyright © 2017. Published by Elsevier Ltd.

Visual Servoing Tracking Control of a Ball and Plate System: Design, Implementation and Experimental Validation

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Ming-Tzu Ho

2013-07-01

Full Text Available This paper presents the design, implementation and validation of real-time visual servoing tracking control for a ball and plate system. The position of the ball is measured with a machine vision system. The image processing algorithms of the machine vision system are pipelined and implemented on a field programmable gate array (FPGA device to meet real-time constraints. A detailed dynamic model of the system is derived for the simulation study. By neglecting the high-order coupling terms, the ball and plate system model is simplified into two decoupled ball and beam systems, and an approximate input-output feedback linearization approach is then used to design the controller for trajectory tracking. The designed control law is implemented on a digital signal processor (DSP. The validity of the performance of the developed control system is investigated through simulation and experimental studies. Experimental results show that the designed system functions well with reasonable agreement with simulations.

Incremental inverse kinematics based vision servo for autonomous robotic capture of non-cooperative space debris

Science.gov (United States)

Dong, Gangqi; Zhu, Z. H.

2016-04-01

This paper proposed a new incremental inverse kinematics based vision servo approach for robotic manipulators to capture a non-cooperative target autonomously. The target's pose and motion are estimated by a vision system using integrated photogrammetry and EKF algorithm. Based on the estimated pose and motion of the target, the instantaneous desired position of the end-effector is predicted by inverse kinematics and the robotic manipulator is moved incrementally from its current configuration subject to the joint speed limits. This approach effectively eliminates the multiple solutions in the inverse kinematics and increases the robustness of the control algorithm. The proposed approach is validated by a hardware-in-the-loop simulation, where the pose and motion of the non-cooperative target is estimated by a real vision system. The simulation results demonstrate the effectiveness and robustness of the proposed estimation approach for the target and the incremental control strategy for the robotic manipulator.

Imagen y discurso de la representación religiosa del Sagrado Corazón de Jesús / Image and discourse of the representation of the Sacred Heart of Jesus

Directory of Open Access Journals (Sweden)

Gabriela Díaz Patiño

2010-01-01

Full Text Available El artículo presenta la historia de la devoción e imagen del Sagrado Corazón de Jesús, desde los primeros indicios de su construcción como imagen devocional hasta la consagración de toda la humanidad a dicha devoción en el año de 1899. El propósito de este recorrido histórico es entender la evolución de los sentidos religiosos otorgados a una imagen devocional a lo largo del tiempo desde la óptica institucional; entender las sutilezas de esas transformaciones a lo largo de espacios de larga duración, así como las innovaciones que en el campo espiritual encuentra la institución eclesiástica para reestructurar los usos y funciones de las imágenes devocionales./ The article presents the history of the cult and image of the Sacred Heart of Jesus, from the first signs of its construction as a devotional image until the consecration of all humanity to the devotion in 1899. The purpose of this historical survey is to understand the evolution of religious meanings given to a devotional image over time from the institutional perspective, to understand the subtleties of these changes over long-term spaces, as well as the innovations that in the spiritual realm the ecclesiastic institution finds to restructure the uses and functions of devotional images.

REDUÇÃO DOS CUSTOS DA QUALIDADE COM MELHORIA DOS PROCESSOS: UM ESTUDO DE CASO

OpenAIRE

Oliveira, Gabriel Rech; Universidade de Caxias do Sul; Motta, Marta Elisete Ventura; Universidade de Caxias do Sul; Camargo, Maria Emilia; Universidade de Caxias do Sul; Tondolo, Vilmar Antonio Gonçalves; Universidade Federal de Rio Grande; Zanadrea, Gabriela; Universidade de Caxias do Sul; Russo, Suzana Leitão; Universidade Federal de Sergipe

2016-01-01

Com o objetivo de se tornarem competitivas, as empresas impulsionam a redução dos custos dos processos que impactam diretamente no preço do produto, destacando-se os custos de qualidade. Neste cenário, a busca pela qualidade total torna-se o caminho para a sobrevivência, devido ao fato da crescente exigência dos clientes para produtos com qualidade superior e preços baixos. Dentre os principais gastos que contribuem para o aumento dos custos da qualidade destacam-se a sucata e retrabalho de p...

Self-regulating the effortful "social dos".

Science.gov (United States)

Cortes, Kassandra; Kammrath, Lara K; Scholer, Abigail A; Peetz, Johanna

2014-03-01

In the current research, we explored differences in the self-regulation of the personal dos (i.e., engaging in active and effortful behaviors that benefit the self) and in the self-regulation of the social dos (engaging in those same effortful behaviors to benefit someone else). In 6 studies, we examined whether the same trait self-control abilities that predict task persistence on personal dos would also predict task persistence on social dos. That is, would the same behavior, such as persisting through a tedious and attentionally demanding task, show different associations with trait self-control when it is framed as benefitting the self versus someone else? In Studies 1-3, we directly compared the personal and social dos and found that trait self-control predicted self-reported and behavioral personal dos but not social dos, even when the behaviors were identical and when the incentives were matched. Instead, trait agreeableness--a trait linked to successful self-regulation within the social domain--predicted the social dos. Trait self-control did not predict the social dos even when task difficulty increased (Study 4), but it did predict the social don'ts, consistent with past research (Studies 5-6). The current studies provide support for the importance of distinguishing different domains of self-regulated behaviors and suggest that social dos can be successfully performed through routes other than traditional self-control abilities. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Real-time markerless tracking for augmented reality: the virtual visual servoing framework.

Science.gov (United States)

Comport, Andrew I; Marchand, Eric; Pressigout, Muriel; Chaumette, François

2006-01-01

Tracking is a very important research subject in a real-time augmented reality context. The main requirements for trackers are high accuracy and little latency at a reasonable cost. In order to address these issues, a real-time, robust, and efficient 3D model-based tracking algorithm is proposed for a "video see through" monocular vision system. The tracking of objects in the scene amounts to calculating the pose between the camera and the objects. Virtual objects can then be projected into the scene using the pose. Here, nonlinear pose estimation is formulated by means of a virtual visual servoing approach. In this context, the derivation of point-to-curves interaction matrices are given for different 3D geometrical primitives including straight lines, circles, cylinders, and spheres. A local moving edges tracker is used in order to provide real-time tracking of points normal to the object contours. Robustness is obtained by integrating an M-estimator into the visual control law via an iteratively reweighted least squares implementation. This approach is then extended to address the 3D model-free augmented reality problem. The method presented in this paper has been validated on several complex image sequences including outdoor environments. Results show the method to be robust to occlusion, changes in illumination, and mistracking.

Plataforma de desarrollo para el control en tiempo real de estructuras cinemáticas con realimentación visual//Platform to develop real time visual servoing control in kinematics systems

Directory of Open Access Journals (Sweden)

René González-Rodríguez

2012-09-01

Full Text Available En este trabajo se presenta una plataforma de desarrollo para el control en tiempo real de estructuras cinemáticas con realimentación visual. Se ha diseñado una configuración genérica que permite la implementación de cualquier variante de control visual. Para el procesamiento de la imagen se ha propuesto una estrategia que permite el uso de diferentes herramientas comerciales o algoritmos propiospara la captura y extracción de características de la imagen. El uso de Real Time Work Shop y Real Time Windows Target en el lazo de control interno brinda la posibilidad de implementar algoritmos de control servovisual en tiempo real. Al final del trabajo se presentan los resultados de un esquema de controlservovisual aplicado en un manipulador industrial. La plataforma propuesta constituye una herramienta de desarrollo para aplicaciones industriales de control servovisual y sirve de apoyo a la enseñanza de la mecatrónica en pregrado y postgrado.Palabras claves: control servovisual, control en tiempo real, estructuras cinemáticas._______________________________________________________________________________AbstractIn this work we propose a platform to develop visual servoing control systems. The platform has a generic design with the possibility to implement direct or look and move visual servoing systems. For the image processing we present a generic design allowing the use of any image processing library like Matrox MIL,Intel IPP, OpenCV or any algorithms for image capture and target characteristics extraction. The uses of Real Time Work Shop and Real Time Windows Target in the internal loop permits modify the control structure in SIMULINK very easy.Key words: visual servoing, real time control, kinematics systems.

Fabrication and correction of freeform surface based on Zernike polynomials by slow tool servo

Science.gov (United States)

Cheng, Yuan-Chieh; Hsu, Ming-Ying; Peng, Wei-Jei; Hsu, Wei-Yao

2017-10-01

Recently, freeform surface widely using to the optical system; because it is have advance of optical image and freedom available to improve the optical performance. For freeform optical fabrication by integrating freeform optical design, precision freeform manufacture, metrology freeform optics and freeform compensate method, to modify the form deviation of surface, due to production process of freeform lens ,compared and provides more flexibilities and better performance. This paper focuses on the fabrication and correction of the free-form surface. In this study, optical freeform surface using multi-axis ultra-precision manufacturing could be upgrading the quality of freeform. It is a machine equipped with a positioning C-axis and has the CXZ machining function which is also called slow tool servo (STS) function. The freeform compensate method of Zernike polynomials results successfully verified; it is correction the form deviation of freeform surface. Finally, the freeform surface are measured experimentally by Ultrahigh Accurate 3D Profilometer (UA3P), compensate the freeform form error with Zernike polynomial fitting to improve the form accuracy of freeform.

Fracture tolerance analysis of the solid rocket booster servo-actuator for the space shuttle

Energy Technology Data Exchange (ETDEWEB)

Smith, S.H.; Ghadiali, N.D.; Zahoor, A.; Wilson, M.R.

1982-01-01

The results of an evaluation of the fracture tolerance of three components of the thrust vector control servo-actuator for the solid rocket booster of the space shuttle are described. These components were considered as being potentially fracture critical and therefore having the potential to fall short of a desired service life of 80 missions (that is, a service life factor of 4.0 on a basic service life of 20 missions). Detailed stress analysis of the rod end, cylinder, and feedback link components was accomplished by three-dimensional finite-element stress analysis methods. A dynamic structural model of the feedback system was used to determine the dynamic inertia loads and reactions to apply to the finite-element model of the feedback link. Twenty mission stress spectra consisting of lift-off, boost, re-entry, and water impact mission segments were developed for each component based on dynamic loadings. Most components were determined to have the potential of reaching a service life of 80 missions or service life factor of 4.0. 22 refs.

A TSR Visual Servoing System Based on a Novel Dynamic Template Matching Method

Directory of Open Access Journals (Sweden)

Jia Cai

2015-12-01

Full Text Available The so-called Tethered Space Robot (TSR is a novel active space debris removal system. To solve its problem of non-cooperative target recognition during short-distance rendezvous events, this paper presents a framework for a real-time visual servoing system using non-calibrated monocular-CMOS (Complementary Metal Oxide Semiconductor. When a small template is used for matching with a large scene, it always leads to mismatches, so a novel template matching algorithm to solve the problem is presented. Firstly, the novel matching algorithm uses a hollow annulus structure according to a FAST (Features from Accelerated Segment algorithm and makes the method be rotation-invariant. Furthermore, the accumulative deviation can be decreased by the hollow structure. The matching function is composed of grey and gradient differences between template and object image, which help it reduce the effects of illumination and noises. Then, a dynamic template update strategy is designed to avoid tracking failures brought about by wrong matching or occlusion. Finally, the system synthesizes the least square integrated predictor, realizing tracking online in complex circumstances. The results of ground experiments show that the proposed algorithm can decrease the need for sophisticated computation and improves matching accuracy.

LA LEGITIMACIÓN DEL LUGAR DE LA RELIGIÓN EN LA COMPRENSIÓN DE LA PERSONA HUMANA: UN ENFOQUE PROBATORIO PARA INTERPRETAR LA FUNCIÓN SIGNIFICATIVA DEL JUEGO SAGRADO

Directory of Open Access Journals (Sweden)

Jeffrey R. Dickson

2016-07-01

Full Text Available La religión a un nivel más institucional y la espiritualidad de una manera más personalmente existencial no respeta el estatus socioeconómico, que se limita al hecho de que un país esté o no desarrollado, o es voluble respecto del lugar donde se arraiga geográficamente. Incluso el movimiento del “nuevo ateísmo” obedece a pseudodoctrinas, demuestra entusiasmo por las creencias profundamente arraigadas e incluso ha empezado a celebrar reuniones en lo que se llaman “megaiglesias” ateas. Parecería que los seres humanos se inclinan al fenómeno de la religión organizada o “juego sagrado” independientemente de su extracción o de qué ubicación histórica acusen. Aunque la religión y la teología y sus correspondientes postulados deberían tener peso en los debates relativos a la persona humana, a menudo estas ciencias se desestiman como secundarias o incluso como innecesarias. Sin embargo, más personas están admitiendo que para entender a la humanidad en general y al individuo en particular se debe incorporar lo que ofrecen estos debates. Como Haslina Ibrahim (2008 reconoce con razón: “Para comprender plenamente al hombre, es vital que reconciliemos el estudio de las religiones con otras ciencias que están incluidas en el estudio de las humanidades”. Con este fin, esta argumentación va a ofrecer una justificación fehaciente de la omnipresencia del juego sagrado y convocar a los lectores a entender un poco de su legitimización en los debates sobre la persona humana. Esto se logrará al construir un compendio de características que se observa en la persona humana y que los científicos sociales suelen observar y luego conectarlas tanto individual como colectivamente al fenómeno del juego sagrado. Abstract Religion on a more institutional level and spirituality in a more personally existential way is not a respecter of socio-economic status, limited to whether or not a country is developed, or fickle about where it

Faulting of rocks in three-dimensional strain fields I. Failure of rocks in polyaxial, servo-control experiments

Science.gov (United States)

Reches, Ze'ev; Dieterich, James H.

1983-05-01

The dependence of the number of sets of faults and their orientation on the intermediate strain axis is investigated through polyaxial tests, reported here, and theoretical analysis, reported in an accompanying paper. In the experiments, cubic samples of Berea sandstone, Sierra-White and Westerly granites, and Candoro and Solnhofen limestones were loaded on their three pairs of faces by three independent, mutually perpendicular presses at room temperature. Two of the presses were servo-controlled and applied constant displacement rates throughout the experiment. Most samples display three or four sets of faults in orthorhombic symmetry. These faults form in several yielding events that follow a stage of elastic deformation. In many experiments, the maximum and the intermediate compressive stresses interchange orientations during the yielding events, where the corresponding strains are constant. The final stage of most experiments is characterized by slip along the faults.

Identidades ambientales, un caso comparativo entre el Trapecio amazónico y el Archipiélago de San Andrés

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Pablo De La Cruz

2014-01-01

Full Text Available A partir de la definición de identidad ambiental, el artículo compara los procesos de transformación identitaria que han tenido lugar en el Trapecio amazónico colombiano y en el Archipiélago de San Andrés, por cuanto son dos casos de redefinición histórica de la etnicidad con referencia al medio geográfico, al encuentro con la colombianidad, a la agudización del discurso y a las tensiones que los capitales y los agentes institucionales generan en torno a lo tradicional. Se analiza el creciente turismo, la influencia de las agencias de cooperación y sus efectos en el desplazamiento de lo sagrado hacia una “cultura teatral”.

Experience with a servo-hydraulic mechanical testing machine installed in a new shielded active facility at Windscale Nuclear Power Development Laboratories

International Nuclear Information System (INIS)

Garlick, A.; Hindmarch, P.; Gravenor, J.G.; Rhodes, D.

1982-03-01

An Instron model 1273 servo-hydraulic machine has been installed within a lead-shielded cell at Windscale in order to provide a facility capable of performing a wide range of mechanical tests on nuclear reactor structural materials and fuel assembly components. This particular type of machine was chosen because it has design features associated with the load frame, location of the actuator and adjustment and clamping of the cross-head that are especially well suited to remote operation within a shielded cell. The design of the testing facility is described and the programmes of work that have been completed over the past 11/2 years of operation are reviewed. (author)

Representações e expectativas dos profissionais dos serviços de pediatria do Hospital de Braga relativamente à intervenção dos "Doutores Palhaços"

OpenAIRE

Almeida, Isabel Cristina Ferreira de

2012-01-01

Dissertação de mestrado em Estudos da Criança (área de especialização em Intervenção Psicossocial com Crianças, Jovens e Famílias) Neste estudo são dadas a conhecer as representações e expetativas dos profissionais de saúde dos serviços de pediatria do Hospital de Braga, relativamente ao trabalho dos palhaços profissionais da Operação Nariz Vermelho: os “Doutores Palhaços” (DP). A recolha dos dados realizou-se cerca de um mês antes do início da intervenção dos DP naquela unidad...

Practical Stabilization of Uncertain Nonholonomic Mobile Robots Based on Visual Servoing Model with Uncalibrated Camera Parameters

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Hua Chen

2013-01-01

Full Text Available The practical stabilization problem is addressed for a class of uncertain nonholonomic mobile robots with uncalibrated visual parameters. Based on the visual servoing kinematic model, a new switching controller is presented in the presence of parametric uncertainties associated with the camera system. In comparison with existing methods, the new design method is directly used to control the original system without any state or input transformation, which is effective to avoid singularity. Under the proposed control law, it is rigorously proved that all the states of closed-loop system can be stabilized to a prescribed arbitrarily small neighborhood of the zero equilibrium point. Furthermore, this switching control technique can be applied to solve the practical stabilization problem of a kind of mobile robots with uncertain parameters (and angle measurement disturbance which appeared in some literatures such as Morin et al. (1998, Hespanha et al. (1999, Jiang (2000, and Hong et al. (2005. Finally, the simulation results show the effectiveness of the proposed controller design approach.

State feedback integral control for a rotary direct drive servo valve using a Lyapunov function approach.

Science.gov (United States)

Yu, Jue; Zhuang, Jian; Yu, Dehong

2015-01-01

This paper concerns a state feedback integral control using a Lyapunov function approach for a rotary direct drive servo valve (RDDV) while considering parameter uncertainties. Modeling of this RDDV servovalve reveals that its mechanical performance is deeply influenced by friction torques and flow torques; however, these torques are uncertain and mutable due to the nature of fluid flow. To eliminate load resistance and to achieve satisfactory position responses, this paper develops a state feedback control that integrates an integral action and a Lyapunov function. The integral action is introduced to address the nonzero steady-state error; in particular, the Lyapunov function is employed to improve control robustness by adjusting the varying parameters within their value ranges. This new controller also has the advantages of simple structure and ease of implementation. Simulation and experimental results demonstrate that the proposed controller can achieve higher control accuracy and stronger robustness. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Servo-controlled hind-limb electrical stimulation for short-term arterial pressure control.

Science.gov (United States)

Kawada, Toru; Shimizu, Shuji; Yamamoto, Hiromi; Shishido, Toshiaki; Kamiya, Atsunori; Miyamoto, Tadayoshi; Sunagawa, Kenji; Sugimachi, Masaru

2009-05-01

Autonomic neural intervention is a promising tool for modulating the circulatory system thereby treating some cardiovascular diseases. In 8 pentobarbital-anesthetized cats, it was examined whether the arterial pressure (AP) could be controlled by acupuncture-like hind-limb electrical stimulation (HES). With a 0.5-ms pulse width, HES monotonically reduced AP as the stimulus current increased from 1 to 5 mA, suggesting that the stimulus current could be a primary control variable. In contrast, the depressor effect of HES showed a nadir approximately 10 Hz in the frequency range between 1 and 100 Hz. Dynamic characteristics of the AP response to HES approximated a second-order low-pass filter with dead time (gain: -10.2 +/- 1.6 mmHg/mA, natural frequency: 0.040 +/- 0.004 Hz, damping ratio 1.80 +/- 0.24, dead time: 1.38 +/- 0.13 s, mean +/- SE). Based on these dynamic characteristics, a servo-controlled HES system was developed. When a target AP value was set at 20 mmHg below the baseline AP, the time required for the AP response to reach 90% of the target level was 38 +/- 10 s. The steady-state error between the measured and target AP values was 1.3 +/- 0.1 mmHg. Autonomic neural intervention by acupuncture-like HES might provide an additional modality to quantitatively control the circulatory system.

A comparative design view for accurate control of servos using a field programmable gate array

International Nuclear Information System (INIS)

Tickle, A J; Harvey, P K; Smith, J S; Wu, F; Buckle, J R

2009-01-01

An embedded system is a special-purpose computer system designed to perform one or a few dedicated functions. Altera DSP Builder presents designers and users with an alternate approach when creating their systems by employing a blockset similar to that already used in Simulink. The application considered in this paper is the design of a Pulse Width Modulation (PWM) system for use in stereo vision. PWM can replace a digital-to-analogue converter to control audio speakers, LED intensity, motor speed, and servo position. Rather than the conventional HDL coding approach this Simulink approach provides an easy understanding platform to the PWM design. This paper includes a comparison between two approaches regarding resource usage and flexibility etc. Included is how DSP Builder manipulates an onboard clock signal, in order to create the control pulses to the 'raw' coding of a PWM generator in VHDL. Both methods were shown to a selection of people and their views on which version they would subsequently use in their relative fields is discussed.

Faulting of rocks in three-dimensional strain fields I. Failure of rocks in polyaxial, servo-control experiments

Science.gov (United States)

Reches, Z.; Dieterich, J.H.

1983-01-01

The dependence of the number of sets of faults and their orientation on the intermediate strain axis is investigated through polyaxial tests, reported here, and theoretical analysis, reported in an accompanying paper. In the experiments, cubic samples of Berea sandstone, Sierra-White and Westerly granites, and Candoro and Solnhofen limestones were loaded on their three pairs of faces by three independent, mutually perpendicular presses at room temperature. Two of the presses were servo-controlled and applied constant displacement rates throughout the experiment. Most samples display three or four sets of faults in orthorhombic symmetry. These faults form in several yielding events that follow a stage of elastic deformation. In many experiments, the maximum and the intermediate compressive stresses interchange orientations during the yielding events, where the corresponding strains are constant. The final stage of most experiments is characterized by slip along the faults. ?? 1983.

Reduced-order model based active disturbance rejection control of hydraulic servo system with singular value perturbation theory.

Science.gov (United States)

Wang, Chengwen; Quan, Long; Zhang, Shijie; Meng, Hongjun; Lan, Yuan

2017-03-01

Hydraulic servomechanism is the typical mechanical/hydraulic double-dynamics coupling system with the high stiffness control and mismatched uncertainties input problems, which hinder direct applications of many advanced control approaches in the hydraulic servo fields. In this paper, by introducing the singular value perturbation theory, the original double-dynamics coupling model of the hydraulic servomechanism was reduced to a integral chain system. So that, the popular ADRC (active disturbance rejection control) technology could be directly applied to the reduced system. In addition, the high stiffness control and mismatched uncertainties input problems are avoided. The validity of the simplified model is analyzed and proven theoretically. The standard linear ADRC algorithm is then developed based on the obtained reduced-order model. Extensive comparative co-simulations and experiments are carried out to illustrate the effectiveness of the proposed method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Servo-Elastic Dynamics of a Hydraulic Actuator Pitching a Blade with Large Deflections

International Nuclear Information System (INIS)

Hansen, M H; Kallesoee, B S

2007-01-01

This paper deals with the servo-elastic dynamics of a hydraulic pitch actuator acting on a largely bend wind turbine blade. The compressibility of the oil and flexibility of the hoses introduce a dynamic mode in the pitch bearing degree of freedom. This mode may obtain negative damping if the proportional gain on the actuator position error is defined too large relative to the viscous forces in the hydraulic system and the total rotational inertia of the pitch bearing degree of freedom. A simple expression for the stability limit of this proportional gain is derived for tuning the gain based on the Ziegler-Nichols method. Computed transfer functions from reference to actual pitch angles indicate that the actuator can be approximated as a low-pass filter with some appropriate limitations on pitching speed and acceleration. The structural blade model includes the geometrical coupling of edgewise bending and torsion for large flapwise deflections. This coupling is shown to introduce edgewise bending response for pitch reference oscillations around the natural frequency of the edgewise bending mode, in which frequency range the transfer function from reference to actual pitch angle cannot be modeled as a simple low-pass filter. The pitch bearing is assumed to be frictionless as a first approximation

OS SACRAMENTAIS, SACRAMENTOS DOS POBRES

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Victor Codina

1990-01-01

Full Text Available Basta ter tido um pouco de experiência pastoral com setores populares, concretamente na América Latina, para constatar a importância dos sacramentais na vida cristã do povo. Além das manifestações de piedade popular que se costuma estudar sob a rubrica de religiosidade popular (peregrinações, festas de padroeiro, procissões..., gostaria de destacar aqui outros elementos mais estreitamente ligados ao mundo dos sacramentos, ainda que não formem parte dos sete sacramentos tridentinos.

Camponeses e esquecimento na Antiguidade Tardia: as revoltas dos bagaudas e dos circunceliões

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Uiran Gebara da Silva

2016-12-01

Full Text Available Esse artigo apresenta alguns dos problemas com os quais eu tive de lidar ao realizar um estudo comparativo entre dois conjuntos de revoltas rurais do Império Romano tardio: as revoltas dos bagaudas na Gália e dos circunceliões na África. O artigo toma como eixo articulador a hipótese lançada por E. A. Thompson sobre o papel do esquecimento na produção dos relatos antigos sobre os bagaudas e a problematiza. Num segundo momento o artigo trata do problema relacionado à compreensão do caráter social de ambos os grupos, levando em consideração os múltiplos relatos presentes nas fontes antigas e as divergentes interpretações modernas sobre eles, enfatizando a necessidade de se reconhecer a tópica da inversão social como um elemento que diferencia os relatos sobre os revoltosos daqueles sobre a bandidagem. Outro elemento importante é o reconhecimento da heterogeneidade dos discursos cristãos com relação às classes subalternas e aos revoltosos, que apontam não para um fortalecimento do patronato rural, mas para o enfraquecimento ou para a crise dessas relações no campo tardo-romano.

Design of decoupled dual servo stage with voice coil motor and linear motor for XY long stroke ultra-precision scanning system

Science.gov (United States)

Kim, Ki-Hyun; Choi, Young-Man; Gweon, Dae-Gab; Hong, Dong-Pyo; Kim, Koung-Suk; Lee, Suk-Won; Lee, Moon-Gu

2005-12-01

A decoupled dual servo (DDS) stage for ultra-precision scanning system is introduced in this paper. The proposed DDS consists of a 3 axis fine stage for handling and carrying workpieces and a XY coarse stage. Especially, the DDS uses three voice coil motors (VCM) as a planar actuation system of the fine stage to reduce the disturbances due to any mechanical connections with its coarse stage. VCMs are governed by Lorentz law. According to the law and its structure, there are no mechanical connections between coils and magnetic circuits. Moreover, the VCM doesn't have force ripples due to imperfections of commutation components of linear motor systems - currents and flux densities. However, due to the VCM's mechanical constraints the working range of the fine is about 5mm2. To break that hurdle, the coarse stage with linear motors is used for the fine stage to move about 200mm2. Because of the above reasons, the proposed DDS can achieve higher precision scanning than other stages with only one servo. Using MATLAB's Sequential Quadratic Programming (SQP), the VCMs are optimally designed for the highest force under conditions and constraints such as thermal dissipations due to its coil, its size, and so on. For linear motors, Halbach magnet linear motor is proposed and optimally designed in this paper. In addition, for their smooth movements without any frictions, guide systems of the DDS are composed of air bearings. And then, precisely to get their positions, linear scales with 0.1um resolution are used for the coarse's XY motions and plane mirror laser interferometers with 20nm for the fine's XYθz. On scanning, the two stages have same trajectories and are controlled. The control algorithm is Parallel method. The embodied ultra-precision scanning system has about 100nm tracking error and in-positioning stability.

Sermão I de Santa Catarina: Latim e Retórica

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João Bortolanza

2007-07-01

Full Text Available Este artigo mostra um pequeno resultado do projeto de pesquisa Ánálise do Latim empregado por Vieira em seus Sermões’. O latim é a própria retórica de Vieira e o levantamento das citações latinas permite reconstruir todo seu labor intelectual. É o que me proponho demonstrar no Sermão I de Santa Catarina, que tem como epígrafe e mote apenas a expressão latina ne forte. A expressão é extraída da frase das virgens prudentes ne forte sufficiat nobis et vobis. Esse “para que não por acaso” passa a ser explorado a partir da etimologia forte > Fortuna, esta, por sua vez, representada pela roda, a roda da Fortuna, sempre instável. E a roda, com a palma e a espada, é um dos troféus da vitória da virgem mártir Catarina em sua imagem. Desfilam frases dos textos sagrados e de clássicos, como Sêneca, Plínio e Plutarco.

Arquitectura precerámica en la cordillera de los Andes, Piruru frene a la diversidad de los datos

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Elisabeth Bonnier

1988-12-01

Full Text Available Los datos sobre la arquitectura precerámica en la cordilleraandina provienen de cinco sitios: La Galgada, Piruru, Huaricoto, Shillacotoy Kotosh. Contexto arqueológico y rasgos arquitectónicos específicos permitenidentificar la función ceremonial de esta arquitectura. La descripciónde las construcciones religiosas pone en evidencia un conjunto pertinente decaracteres comunes. El espacio ceremonial, construido y sin construir, se articulaalrededor del doble elemento arquitectónico fundamental, el fogón yel piso. Para analizar el piso a dos niveles, dos neologismos, pericausto y epicaustohan sido creados. El análisis arquitectónico muestra que el piso es elespacio sagrado por excelencia. Los fechados 14C de los sitios estudiadosdestacan la larga duración del Precerámico Final con arquitectura. A la luz delos últimos trabajos en Piruru y de los cambios arquitectónicos perceptiblesen este sitio, la hipótesis, formulada a principios de este decenio, sobre ·taexistencia de una tradición religiosa única propia de los Andes Centrales, seestá reconsiderando.

REDUÇÃO DOS CUSTOS DA QUALIDADE COM MELHORIA DOS PROCESSOS: UM ESTUDO DE CASO

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Gabriel Rech Oliveira

2016-06-01

Full Text Available Com o objetivo de se tornarem competitivas, as empresas impulsionam a redução dos custos dos processos que impactam diretamente no preço do produto, destacando-se os custos de qualidade. Neste cenário, a busca pela qualidade total torna-se o caminho para a sobrevivência, devido ao fato da crescente exigência dos clientes para produtos com qualidade superior e preços baixos. Dentre os principais gastos que contribuem para o aumento dos custos da qualidade destacam-se a sucata e retrabalho de produtos durante o processo produtivo. Devido à ocorrência desses fatores, este trabalho tem como finalidade analisar os custos da qualidade e propor melhorias no processo produtivo utilizando ferramentas da qualidade para reduzir os desperdícios com sucata. As fases do projeto envolvem o comprometimento e dedicação de equipes para levantar as principais causas dos principais problemas do processo de produção de tubos capilares em cobre, resultando na redução dos gastos com sucata e aumento da produtividade. As metodologias utilizadas para atingir os objetivos foram baseadas pesquisa exploratória e estudo de caso. A partir da redução de custo e aumento da produtividade alcançada, constata-se a importância deste trabalho envolvendo equipes responsáveis para a obtenção de resultados em curto prazo.

Novel Round Energy Director for Use with Servo-driven Ultrasonic Welder

Science.gov (United States)

Savitski, Alex; Klinstein, Leo; Holt, Kenneth

Increasingly stringent process repeatability and precision of assembly requirements are common for high-volume manufacturing for electronic, automotive and especially medical device industries, in which components for disposable medication delivery devices are produced in hundreds of millions annually. Ultrasonic welding, one of the most efficient of plastic welding processes often joins these small plastic parts together, and quite possibly, the one most broadly adopted for high volume assembly. The very fundamental factor in ultrasonic welding process performance is a proper joint design, the most common of which is a design utilizing an energy director. Keeping the energy director size and shape consistent on a part-to-part basis in high volume, multi-cavity operations presents a constant challenge to molded part vendors, as dimensional variations from cavity to cavity and variations in the molding process are always present. A newly developed concept of energy director design, when the tip of the energy director is round, addresses these problems, as the round energy director is significantly easier to mold and maintain its dimensional consistency. It also eliminates a major source of process variability for assembly operations. Materializing the benefits of new type of joint design became possible with the introduction of servo-driven ultrasonic welders, which allow an unprecedented control of material flow during the welding cycle and results in significantly improved process repeatability. This article summarizes results of recent studies focused on evaluating performance of round energy director and investigating the main factors responsible for the joint quality.

Neurobiologia dos transtornos do controle dos impulsos The neurobiology of impulse control disorders

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Wendol A Williams

2008-05-01

Full Text Available OBJETIVO: Revisar os artigos sobre substratos neurobiológicos dos transtornos do controle dos impulsos. O jogo patológico é o foco central desta revisão na medida em que a maioria dos estudos biológicos dos formalmente classificados como transtornos do controle dos impulsos examinou este transtorno. MÉTODO: Foi feita uma busca no banco de dados Medline de artigos publicados de 1966 até o presente para identificar aqueles relevantes para serem revisados neste artigo. DESFECHOS: Estudos pré-clínicos sugerem que a neuromodulação das monoaminas cerebrais está associada à tomada de decisões impulsivas e aos comportamentos de risco. Os estudos clínicos implicam diversos sistemas de neurotransmissores (serotoninérgico, dopaminérgico, adrenérgico e opióide na fisiopatologia do jogo patológico e de outros transtornos do controle dos impulsos. Estudos de neuroimagem preliminares têm indicado o córtex pré-frontal ventromedial e o estriato ventral como atuantes na fisiopatologia do jogo patológico e de outros transtornos do controle dos impulsos. As contribuições genéticas para o jogo patológico parecem substanciais e os estudos iniciais têm relacionado esse transtorno a polimorfismos alélicos específicos, ainda que os achados de varredura genômica ainda tenham que ser publicados. CONCLUSÃO: Mesmo que tenham sido logrados avanços significativos em nossa compreensão sobre os transtornos do controle dos impulsos, mais pesquisas são necessárias para ampliar o conhecimento existente e traduzir esses achados em avanços clínicos.OBJECTIVE: To review the neurobiological substrates of impulse control disorders. Pathological gambling is a main focus of the review in that most biological studies of the formal impulse control disorders have examined this disorder. METHOD: The medical database Medline from 1966 to present was searched to identify relevant articles that were subsequently reviewed to generate this manuscript

Participação dos Pais na Psicoterapia da Criança: Práticas dos Psicoterapeutas

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Luiz Ronaldo Freitas de Oliveira

Full Text Available Resumo A participação dos pais na psicoterapia de crianças é um tema controverso na literatura. Há autores a favor de uma abordagem mais intervencionista em relação aos pais e outros que circunscrevem seu papel à manutenção do tratamento e provimento de informações sobre a criança. O objetivo deste estudo exploratório, de levantamento, transversal, foi identificar experiências de psicoterapeutas de crianças brasileiros quanto às formas de inclusão dos pais no tratamento. Participaram 76 psicólogos, que responderam a um questionário on-line e as análises contemplaram estatística descritiva e análise de conteúdo. De acordo com os resultados, os respondentes foram predominantemente mulheres (89,5%, residentes na Região Sul (86,8%, entre 26 e 35 anos (53,9% e com até três anos de experiência clínica (43,4%. De maneira geral, os participantes incluem os pais na psicoterapia (76,3%; em entrevistas específicas (90,8%; coleta de informações (88,2%, para aconselhamento/orientação (72,4%; e para fortalecer a aliança terapêutica (61,8%. Riscos e benefícios da participação dos pais foram reportados e constituíram seis categorias: a criança como sintoma dos conflitos familiares; resistência dos pais à psicoterapia e às mudanças; cumprimento do contrato pelos pais; aliança terapêutica; compreensão da dinâmica familiar e dos sintomas da criança; e fortalecimento dos vínculos pais-filhos. Conclui-se que há tendência de inclusão dos pais, por parte dos psicoterapeutas, no processo de psicoterapia de crianças.

Guerra e Paz, por David Grossman

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Luis Sérgio Krausz

2010-03-01

Full Text Available Na Bíblia Hebraica, a guerra é um assunto diretamente vinculado à esfera do sagrado. A proteção de Deus ao povo de Israel em suas batalhas é, assim, um dos fundamentos da teologia bíblica. No romance, A mulher foge, de David Grossman, como em Homero, a realidade da guerra contrapõe-­se à realidade das pessoas comuns e, assim, separa, em um vasto abismo, as experiências deste e daquele lado. Ao contrário do que acontece na Bíblia, e também na Ilíada, não há, nas guerras do romance, qualquer tipo de crença divina, seja ela de molde pagão, seja ela de caráter retributivo, conforme a teologia bíblica.

A temática da humanização na saúde: alguns apontamentos para debate

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Waldir da Silva Souza

Full Text Available A humanização na saúde é tematizada segundo uma digressão sociohistórica sobre as bases do humanismo no Ocidente e sua atual diluição em diversos setores da vida social; diluição esta qualificada com um tom positivo, essencialista, que contribui para que o humanismo seja identificado como um "bem sagrado" ou uma grife. Buscando problematizar esta questão, foram considerados os documentos produzidos pela Política Nacional de Humanização, confrontando o princípio constitucional da integralidade com a orientação da humanização. Nos documentos, a perspectiva da "produção da saúde" engloba: a atenção ou prestação do cuidado (práticas profissionais, a gestão dos processos de trabalho e a participação dos usuários ou controle social no interior dos processos de trabalho na saúde. Conclui-se que discutir humanização significa: rever idealizações que desconsideram os limites do humano, admitir o conflito como motor de negociações, e colocar em análise a forma como os grupos se organizam em seus processos de trabalho.

As contribuições da civilização egípcia na literatura e na educação: primeiras relações históricas entre texto verbal e texto não verbal

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Gabriela Cruz Vásquez

2017-07-01

Full Text Available O objetivo deste estudo é o de identificar as contribuições da civilização egípcia na literatura e na educação a partir da união do texto verbal e do texto não verbal em uma única obra, que foi uma das características nas estruturas literárias da civilização do Antigo Egito. Para discutir esse tema utiliza-se um documento histórico, o Papiro do Livro dos Mortos de Ani, tendo como foco de investigação o paradigma indiciário na decifração dos signos textuais e dos signos visuais. Mediante uma análise interpretativa são identificadas as relações entre o verbal e o não verbal nesse documento histórico para verificar suas contribuições, intenção didática, colaboração disciplinar, qualidade de fonte histórica, eternidade e reinvenção, complementariedade, autonomia e independência, o mágico, o maravilhoso e o sagrado, as quais poderiam ser integradas à literatura e à educação contemporânea.

A numerical study of cavitation phenomenon in a flapper-nozzle pilot stage of an electrohydraulic servo-valve with an innovative flapper shape

International Nuclear Information System (INIS)

Aung, Nay Zar; Li, Songjing

2014-01-01

Highlights: • The flapper with curved edge develops a significant cavitation in pilot stage. • The rectangular shape flapper significantly reduces cavitation in pilot stage. • The innovative flapper eliminates undesired transverse lateral force. • The innovative flapper maintains the same flow control capability and construction. - Abstract: The flapper-nozzle pilot stage, whose performance can be deteriorated by the generated flow cavitation phenomenon, is a vital segment in achieving precise control of electrohydraulic servo-valves. Aiming to find out a reasonable flapper shape to reduce cavitation, this paper presents a numerical study of cavitation phenomenon in a flapper-nozzle pilot stage with different flapper shapes. A simple rectangular shape, carefully designed without disturbing the flow control characteristics of the pilot stage, is set as an innovative flapper shape in this work. Cavitation phenomena in the pilot stage are simulated for both of the traditionally used flapper shape and the innovative flapper shape at flow conditions with various nozzle inlet pressures, 1 MPa to 7 MPa. Then, systematic comparison of resulted cavitation phenomena for the two different flapper shapes is carried out. The results confirm that, for both flapper shapes, cavitation commonly occurs along the nozzle tip wall beyond stagnation region. The curved edge in traditionally used flapper shape is a massive contributor of cavitation in the pilot stage and the selected innovative shape shows a significant reduction of cavitation on its surface. From the flow structure, it is also noticeable that undesired transverse lateral force of sheded vortices is eliminated by using the innovative flapper shape. Meanwhile, the innovative flapper shape highlights the same effectiveness on the performance of flow control as the traditionally used flapper shape. Thus, a simple and effective flapper shape is proposed for cavitation reduction in the flapper-nozzle pilot stage of an

Simple and robust phase-locking of optical cavities with > 200 KHz servo-bandwidth using a piezo-actuated mirror mounted in soft materials.

Science.gov (United States)

Goldovsky, David; Jouravsky, Valery; Pe'er, Avi

2016-12-12

We present an approach to locking of optical cavities with piezoelectric actuated mirrors based on a simple and effective mechanical decoupling of the mirror and actuator from the surrounding mount. Using simple elastic materials (e.g. rubber or soft silicone gel pads) as mechanical dampers between the piezo-mirror compound and the surrounding mount, a firm and stable mounting of a relatively large mirror (8mm diameter) can be maintained that is isolated from external mechanical resonances, and is limited only by the internal piezo-mirror resonance of > 330 KHz. Our piezo lock showed positive servo gain up to 208 KHz, and a temporal response to a step interference within < 3 μs.

Optimal design of a main driving mechanism for servo punch press based on performance atlases

Science.gov (United States)

Zhou, Yanhua; Xie, Fugui; Liu, Xinjun

2013-09-01

The servomotor drive turret punch press is attracting more attentions and being developed more intensively due to the advantages of high speed, high accuracy, high flexibility, high productivity, low noise, cleaning and energy saving. To effectively improve the performance and lower the cost, it is necessary to develop new mechanisms and establish corresponding optimal design method with uniform performance indices. A new patented main driving mechanism and a new optimal design method are proposed. In the optimal design, the performance indices, i.e., the local motion/force transmission indices ITI, OTI, good transmission workspace good transmission workspace(GTW) and the global transmission indices GTIs are defined. The non-dimensional normalization method is used to get all feasible solutions in dimensional synthesis. Thereafter, the performance atlases, which can present all possible design solutions, are depicted. As a result, the feasible solution of the mechanism with good motion/force transmission performance is obtained. And the solution can be flexibly adjusted by designer according to the practical design requirements. The proposed mechanism is original, and the presented design method provides a feasible solution to the optimal design of the main driving mechanism for servo punch press.

Multi-objective optimum design of fast tool servo based on improved differential evolution algorithm

International Nuclear Information System (INIS)

Zhu, Zhiwei; Zhou, Xiaoqin; Liu, Qiang; Zhao, Shaoxin

2011-01-01

The flexure-based mechanism is a promising realization of fast tool servo (FTS), and the optimum determination of flexure hinge parameters is one of the most important elements in the FTS design. This paper presents a multi-objective optimization approach to optimizing the dimension and position parameters of the flexure-based mechanism, which is based on the improved differential evolution algorithm embedding chaos and nonlinear simulated anneal algorithm. The results of optimum design show that the proposed algorithm has excellent performance and a well-balanced compromise is made between two conflicting objectives, the stroke and natural frequency of the FTS mechanism. The validation tests based on finite element analysis (FEA) show good agreement with the results obtained by using the proposed theoretical algorithm of this paper. Finally, a series of experimental tests are conducted to validate the design process and assess the performance of the FTS mechanism. The designed FTS reaches up to a stroke of 10.25 μm with at least 2 kHz bandwidth. Both of the FEA and experimental results demonstrate that the parameters of the flexure-based mechanism determined by the proposed approaches can achieve the specified performance and the proposed approach is suitable for the optimum design of FTS mechanism and of excellent performances

Informatividade dos lucros contábeis e divulgação dos ativos biológicos: evidências brasileiras

OpenAIRE

Holanda, Allan Pinheiro

2013-01-01

A pesquisa tem o objetivo de investigar a influência exercida pela divulgação dos ativos biológicos na informatividade dos lucros contábeis nas firmas brasileiras listadas na BM&FBovespa, considerando-se o período de 2010 a 2011. Para a investigação da informatividade dos ativos biológicos foi utilizada a adaptação dos modelos propostos por Easton e Harris (1991) e Francis e Schipper (1999). Os ativos biológicos, por sua vez, foram mensurados de duas maneiras, pela simples existência da c...

Desenvolvimento e avaliação de uma servoválvula de baixo custo para a aplicação de insumos líquidos Development and evaluation of a low cost servo-valve for liquid inputs application

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André L. Johann

2006-04-01

Full Text Available O presente trabalho teve o objetivo de desenvolver uma servoválvula de baixo custo, que respondesse a um sinal eletrônico de controle, para a aplicação de insumos líquidos a taxas variáveis. Depois de realizada pesquisa na literatura das opções de válvulas existentes para a dosagem de líquidos a baixas pressões, partiu-se para o desenvolvimento de uma válvula proporcional com acionamento mecânico por intermédio de um servomotor controlado eletronicamente. Uma vez desenvolvida a servoválvula, o sistema foi submetido a um conjunto de testes, realizados em bancada desenvolvida especificamente para esse fim, onde se procurou avaliar seu comportamento em termos de repetitividade, histerese e linearidade. Como resultados, obtiveram-se três curvas de vazão em função do percentual de abertura, descrevendo três incrementos de abertura e fechamento em duas pressões diferentes de trabalho. A servoválvula apresentou boa repetitividade, razoável histerese e curva tipicamente quadrática, bem como manteve a proposta de baixo custo. Esses resultados apresentaram-se bastante satisfatórios, uma vez que a não-linearidade e a histerese podem ser facilmente corrigidas por meio de software.The present work aimed the development of a low cost servo-valve that answers to an electronic control signal, for variable rates liquid inputs application. A literature research to define which valve type should be used was made. A mechanically activated proportional valve with an electronically controlled servo-engine was designed and evaluated. Since developed the servo-valve, the system was submited to a number of tests .The evaluation of its behavior was obtained in terms of repeatability, hystheresis and linearity. The test was accomplished in a bench, specially developed for this aim. As a result, were obtained three curves of opening percentage as function of flow rate, describing three opening and closing increments in two different work pressures

Nationalism in third world countries

OpenAIRE

Abugattas, Juan

1982-01-01

Hay, en cada época, verdades evidentes que se prefieren ignorar. En la nuestra, una de esas verdades es que la división territorial del mundo es producto del azar y de la pugna de intereses, y que nada hay necesario o inherente en ella. Así, real o supuestamente ignorantes, concebimos las fronteras y actuamos frente a ellas como si fueran límites sagrados, linderos fijados por poderes semidivinos de manera definitiva. Algunos, los menos, ciertamente se benefician con el carácter sagrado de lo...

Adaptive servo-ventilation therapy for patients with chronic heart failure in a confirmatory, multicenter, randomized, controlled study.

Science.gov (United States)

Momomura, Shin-Ichi; Seino, Yoshihiko; Kihara, Yasuki; Adachi, Hitoshi; Yasumura, Yoshio; Yokoyama, Hiroyuki; Wada, Hiroshi; Ise, Takayuki; Tanaka, Koichi

2015-01-01

Adaptive servo-ventilation (ASV) therapy is expected to be novel nonpharmacotherapy with hemodynamic effects on patients with chronic heart failure (CHF), but sufficient evidence has not been obtained. A 24-week, open-label, randomized, controlled study was performed to confirm the cardiac function-improving effect of ASV therapy on CHF patients. At 39 institutions, 213 outpatients with CHF, whose left ventricular ejection fraction (LVEF) was control group], respectively. The primary endpoint was LVEF, and the secondary endpoints were HF deterioration, B-type natriuretic peptide (BNP), and clinical composite response (CCR: NYHA class+HF deterioration). LVEF and BNP improved significantly at completion against the baseline values in the 2 groups. However, no significant difference was found between these groups. HF deterioration tended to be suppressed. The ASV group showed a significant improvement in CCR corroborated by significant improvements in NYHA class and ADL against the control group. Under the present study's conditions, ASV therapy was not superior to GDMT in the cardiac function-improving effect but showed a clinical status-improving effect, thus indicating a given level of clinical benefit.

On-machine measurement of a slow slide servo diamond-machined 3D microstructure with a curved substrate

International Nuclear Information System (INIS)

Zhu, Wu-Le; Yang, Shunyao; Ju, Bing-Feng; Jiang, Jiacheng; Sun, Anyu

2015-01-01

A scanning tunneling microscope-based multi-axis measuring system is specially developed for the on-machine measurement of three-dimensional (3D) microstructures, to address the quality control difficulty with the traditional off-line measurement process. A typical 3D microstructure of the curved compound eye was diamond-machined by the slow slide servo technique, and then the whole surface was on-machine scanned three-dimensionally based on the tip-tracking strategy by utilizing a spindle, two linear motion stages, and an additional rotary stage. The machined surface profile and its shape deviation were accurately measured on-machine. The distortion of imaged ommatidia on the curved substrate was distinctively evaluated based on the characterized points extracted from the measured surface. Furthermore, the machining errors were investigated in connection with the on-machine measured surface and its characteristic parameters. Through experiments, the proposed measurement system is demonstrated to feature versatile on-machine measurement of 3D microstructures with a curved substrate, which is highly meaningful for quality control in the fabrication field. (paper)

O Jardim dos Sonhos

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RAUL CÂNOVAS

2010-06-01

Full Text Available O jardim dos sonhos sempre foi um ideal dos homens. No Antigo Egito, já se falava em um jardim sempre verde para onde as pessoas de bom coração iam após a morte. E na mitologia grega, um lindo jardim era palco das festas bucólicas dos deuses. As grandes religiões também citavam jardins como paraísos, como o Jardim do Éden. Neste artigo, Raul Cânovas nos leva a refletir sobre o sentido de um “jardim perfeito”, sem tratar a perfeição como apenas plástica e estruturada com exatidão, mas referindo-se a um jardim que nos inspire e emocione, emancipado de modismos passageiros. O paisagista também nos alerta sobre as condições mutáveis de um jardim, que nunca está finalizado. O paisagismo não é apenas técnica; é também sensibilidade, utilidade, sustentabilidade e equilíbrio das forças da natureza.

Os Fungos no Funcionamento dos Ecossistemas Florestais

OpenAIRE

Santos-Silva, Celeste; Machado, Helena

2011-01-01

Os fungos no funcionamento dos ecossistemas Florestais: Papel dos fungos sapróbios na degradação da matériaorgânica Papel dos fungos micorrízicos na nutrição e saúde das árvores Diversidade fúngica e estabilidade das florestas Relações entre os fungos e os animais Doenças radiculares associadas ao declínio do montado de sobro e azinho

El estatuto y la representación del cuerpo humano en el sistema jurídico

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DANIEL BORRILLO

1994-01-01

Full Text Available La evolución biotecnológica ha permitido un uso amplio de órganos y productos del cuerpo humano. Individualmente se puede disponer del cuerpo en centros de investigación o en industrias. Los debates jurídicos y éticos presentan una oposición entre dos puntos de vista. Por una parte, están los que piensan el cuerpo como objeto y, por otro lado, quienes consideran que el cuerpo es inalcanzable e invalorable para la persona. el carácter de la "cuestión corporal" hace insuficiente este tipo de dicotomía. Esto es sagrado bajo ciertas circunstancias e instrumental bajo otras. Para una protección jurídica del cuerpo es importante la interpretación de los diferentes aspectos que intenta interpretar el dualismo clásico.

[Development of a gait trainer with regulated servo-drive for rehabilitation of locomotor disabled patients].

Science.gov (United States)

Uhlenbrock, D; Sarkodie-Gyan, T; Reiter, F; Konrad, M; Hesse, S

1997-01-01

The aim of the present study was to develop a new gait trainer for the rehabilitation of non-ambulatory patients. For the simulation of the gait phase, we used a commercially available fitness trainer (Fast Track) with two foot plates moving in an alternating fashion and connected to a servo-controlled propulsion system providing the necessary support for the movement depending on the patient's impairment level. To compensate deficient equilibrium reflexes, the patient was suspended in a harness capable of supporting some of his/her weight. Video analysis of gait and the kinesiological EMG were used to assess the pattern of movement and the corresponding muscle activity, which were then evaluated in healthy subjects, spinal cord injured and stroke patients and compared with walking on the flat or on a treadmill. Walking on the gait trainer was characterised by a symmetrical, sinusoidal movement of lower amplitude than in normal gait. The EMG showed a low activity of the tibialis anterior muscle, while the antigravity muscles were clearly activated by the gait trainer during the stance phase. In summary, the new gait trainer generates a symmetrical gait-like movement, promoting weight acceptance in the stance phase, which is important for the restoration of walking ability.

A percepção dos trabalhadores de enfermagem sobre o manejo dos resíduos químicos perigosos

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Taiza Florêncio Costa

2012-12-01

Full Text Available Este estudo objetivou identificar a percepção dos trabalhadores de enfermagem sobre o manejo dos resíduos químicos perigosos no Hospital Universitário da Universidade de São Paulo e elaborar uma proposta para o manejo desses resíduos. Trata-se de pesquisa de abordagem qualitativa, cuja amostra foi intencional, composta por dezoito trabalhadores de enfermagem. A coleta de dados foi realizada por meio da técnica de grupo focal. Com a análise temática foram identificadas quatro categorias que evidenciaram a deficiência de treinamento nas etapas do manejo, como a primeira dificuldade expressa, tendo aparecido ainda o desconhecimento da exposição e impactos, assim como o uso dos equipamentos de proteção individual em detrimento da proteção coletiva, seguidos das sugestões quanto às medidas de competência institucional e dos trabalhadores para o manejo seguro dos resíduos químicos perigosos. Esses dados permitiram recomendar propostas para o manejo adequado dos resíduos químicos perigosos pela enfermagem.

A percepção dos trabalhadores de enfermagem sobre o manejo dos resíduos químicos perigosos

Directory of Open Access Journals (Sweden)

Taiza Florêncio Costa

Full Text Available Este estudo objetivou identificar a percepção dos trabalhadores de enfermagem sobre o manejo dos resíduos químicos perigosos no Hospital Universitário da Universidade de São Paulo e elaborar uma proposta para o manejo desses resíduos. Trata-se de pesquisa de abordagem qualitativa, cuja amostra foi intencional, composta por dezoito trabalhadores de enfermagem. A coleta de dados foi realizada por meio da técnica de grupo focal. Com a análise temática foram identificadas quatro categorias que evidenciaram a deficiência de treinamento nas etapas do manejo, como a primeira dificuldade expressa, tendo aparecido ainda o desconhecimento da exposição e impactos, assim como o uso dos equipamentos de proteção individual em detrimento da proteção coletiva, seguidos das sugestões quanto às medidas de competência institucional e dos trabalhadores para o manejo seguro dos resíduos químicos perigosos. Esses dados permitiram recomendar propostas para o manejo adequado dos resíduos químicos perigosos pela enfermagem.

A Teoria dos Conjuntos de Cantor

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Antônio Acra Freiria

1992-07-01

Full Text Available No final dos anos 50 e começo doe anos 60, houve uma reformulação significativa da Matemática no Brasil. Sob a bandeira do modernismo, seus defensores buscaram inovações no ensino da Matemática. Dessa forma, os reformistas se concentraram essencialmente na linguagem abusiva e no formalismo da Teoria dos Conjuntos, o que trouxe mais danos do que benefícios do ensino da Matemática de 1º e 2ºgraus. A linguagem formal da Teoria dos Conjuntos é porém sua parte menos importante. A teoria criada por Cantor tão logo revelou-se como o fundamento de toda a Matemática, possibilitando o desenvolvimento de novas disciplinas, como a Topologia, a Algebra Abstrata, a Teoria da Medida e Integração, a Teoria da Probabilidade e a Análise Funcional. O objetivo deste trabalho é um relato sucinto de como surgiu essa teoria, apresentando o "Conjunto de Cantor" como um dos mais ricos exemplos de "Conjunto perfeito" encontrados na literatura matemática.

O EQUIVALENTE EM CARBONATO DE CÁLCIO DOS CORRETIVOS DA ACIDEZ DOS SOLOS

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J.C. ALCARDE

1996-05-01

Full Text Available Os corretivos da acidez dos solos podem ter dois equivalentes em carbonato de cálcio: um, calculado pelos teores de cálcio e magnésio utilizando a expressão: % CaO x 1,79 + % MgO x 2,48 = %ECaCO3; outro, determinado analiticamente pelo poder ou valor de neutralização. Para uma mesma amostra ambos os valores deveriam coincidir, o que raramente acontece. Diversas hipóteses foram levantadas para justificar essa diferença. Os resultados deste trabalho permitiram inferir que nem todo o cálcio e magnésio dos corretivos devem estar associados às bases quimicamente efetivas mas também a fosfato, sulfato ou outras bases de forças inexpressivas; também os constituintes neutralizantes podem estar aprisionados em cristais de outros componentes dos corretivos, como sílica por exemplo, que só são atingidos por um ataque mais enérgico da amostra. Como conclusão, a avaliação química atual dos corretivos da acidez dos solos pode não estar se compatibilizando com o comportamento agrícola desses produtos.Agricultural liming materials can have two calcium carbonate equivalents: one calculated in function of calcium and magnesium oxide percentages, by the expression: % CaO x 1,79 + % MgO x 2,48 = %ECaCO3; and the other determined analytically by the neutralization power or value. For one sample, both values should be similar, however, this rarely occurs. Several hypoteses were raised to justify the difference. Results of this research permit to infer that not all calcium and magnesium should be associated to the chemically effective bases, but they are also associated to phosphate, sulphate or other bases of inexpressive strength. It is also possible that, the neutralizing components could be captured inside cristals, like silica for example, which react only after a strong solubilization of the sample. It is concluded that the chemical evaluation of agricultural liming materials at the present time cannot explain the agronomical behaviour of

Tratamento descentralizado de esgotos de empreendimentos comercial e residencial empregando a ecotecnologia dos wetlandsconstruídos

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Camila Maria Trein

Full Text Available ResumoO objetivo deste trabalho é apresentar o desempenho dos wetlandsconstruídos de fluxo vertical (WCFV submetidos a diferentes carregamentos orgânicos e hidráulicos, a fim de incorporar esta tecnologia como opção no tratamento descentralizado de esgotos em empreendimentos comercial e residencial. Avaliou-se ao longo de dois anos dois sistemas de tratamento: (i sistema 1 - empreendimento comercial: composto por um Reator Aneróbio Compartimentado (RAC seguido de WCFV (área superficial total de 189 m2; (ii sistema 2 - condomínio residencial: composto pela sequência RAC e WCFV com fundo saturado (área superficial total de 3.141 m2. Com o monitoramento operacional e analítico junto aos wetlands, determinaram-se taxas hidráulicas aplicadas variando de 130 a 12 mm.d-1 e carregamentos médios aplicados variando de 87 a 1,9 gDQO m-2.d-1 para os sistemas 1 e 2, respectivamente. Os distintos carregamentos foram resultantes da demanda atual dos empreendimentos, sendo que os sistemas 1 e 2 apresentaram eficiências médias globais de remoção em termos de concentração de 75% e 93% para DQO, de 88% e 97% para DBO e de 83% e 94% para SS, respectivamente. A partir dos resultados obtidos, recomenda-se a utilização dos WCFV como alternativa tecnológica de tratamento de esgoto sob o contexto da descentralização.

O Cabimento dos Embargos de Divergência

OpenAIRE

LOURENCO, S. R.

2012-01-01

A presente pesquisa objetiva demonstrar os embargos de divergência com enfoque nos elementos processuais do cabimento de tal modalidade recursal em nosso ordenamento jurídico. Para tanto, investigaremos os aspectos gerais dos embargos de divergência, a partir da análise dos elementos históricos enquanto a criação do instituto, como também sua finalidade e classificação no ordenamento jurídico brasileiro. Após, analisaremos o requisito de admissibilidade do cabimento dos embargo...

Application of a Self-recurrent Wavelet Neural Network in the Modeling and Control of an AC Servo System

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Run Min HOU

2014-05-01

Full Text Available To control the nonlinearity, widespread variations in loads and time varying characteristic of the high power ac servo system, the modeling and control techniques are studied here. A self-recurrent wavelet neural network (SRWNN modeling scheme is proposed, which successfully addresses the issue of the traditional wavelet neural network easily falling into local optimum, and significantly improves the network approximation capability and convergence rate. The control scheme of a SRWNN based on fuzzy compensation is expected. Gradient information is provided in real time for the controller by using a SRWNN identifier, so as to ensure that the learning and adjusting function of the controller of the SRWNN operate well, and fuzzy compensation control is applied to improve rapidity and accuracy of the entire system. Then the Lyapunov function is utilized to judge the stability of the system. The experimental analysis and comparisons with other modeling and control methods, it is clearly shown that the validities of the proposed modeling scheme and control scheme are effective.

Sacrifício rei, estado ruandês e genocídio

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Christopher C. Taylor

Full Text Available Em contraste com as análises do genocídio ruandês de 1994, que privilegiam o político, este artigo sustenta que o poder e a política durante o tempo que precedeu o genocídio foram afetadas por noções ruandesas específicas de cosmologia e ontologia. Para entender esse componente "imaginário" da violência, precisamos examinar atentamente as crenças e práticas relacionadas com a instituição da realeza sagrada em Ruanda. Embora essas crenças e práticas foram oficialmente encerradas em 1931, quando o último rei de Ruanda sagrado foi deposto e substituído por seu filho educado por missionários, a sua matriz cosmológica manteve-se em tempos recentes. Isto pode ser visto na literatura popular de rua Ruandesa, que circulou amplamente nos dias que antecederam o genocídio. Nessa literatura, o então presidente Juvenal Habyarimana era comparado explicitamente a um rei ruandês. Mais importante ainda para os objetivos deste artigo, foi a comparação mais difusa, implícita, e simbólica entre Habyarimana e um rei sagrado. Em particular, alguns dos elementos-chave neste simbolismo iluminam (e mostram a importância da persistência da imagem de como um rei (ou presidente deveria se comportar. Como havia muitos jornalistas ruandeses reacionários (e racistas que tinham começado a duvidar da capacidade do presidente Habyarimana de ser um "bom rei", seu "sacrifício"'subseqüente estava, em um sentido simbólico, fortemente predestinado.

Teaching Bibliometric Analysis and MS/DOS Commands.

Science.gov (United States)

Dou, Henri; And Others

1988-01-01

Outlines the steps involved in bibliometric studies, and demonstrates the ability to execute simple studies on microcomputers by downloading files using only the capability of MS/DOS. Detailed illustrations of the MS/DOS commands used are provided. (eight references) (CLB)

O ecologismo dos pobres

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Juan Martinez ALIER

1997-12-01

Full Text Available O ecologísmo tem colocado em cheque as leis capitalistas de mercado, principalmente na sua fase globalizada, devido à apropriação e exploração inconsequente dos recursos naturais. Ao mesmo tempo tem apontado que o meio ambiente não se reduz ao tratamento somente cientifico da natureza. O presente artigo ressalta aspectos importantes do ecologísmo como a participação das mulheres, o marxismo, o neo-narodnismo, etc. e é rico em exemplos de problemas ambientais decorrentes das relações de produção. O ecologísmo dos pobres é apontado como uma perspectiva necessária às lutas ambientais no Terceiro Mundo.

Negro é o inferno! Um ensaio sobre as cores dos homens, dos demônios e dos deuses

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Walker Douglas Pincerati

2016-10-01

Full Text Available http://dx.doi.org/10.5007/1984-8420.2016v17n2p46 Problematiza-se o par negro.branco na formação social brasileira, trabalhando a hipótese de que ‘negro’ não é cor, mas a metáfora do corpo do ser infernal. Estatísticas oficiais, a história da formação do Brasil, um enunciado de um Deputado Federal Pastor, o quadro A libertação dos Escravos de Pedro Américo (1889 e a história da construção das catedrais góticas medievais são evocadas para analisá-lo, desde o ponto de vista linguístico-discursivo. Nota-se, destarte, uma longa história do alinhamento dos significantes branco-luz-deuses-céu-liberdade... e negro-escuridão-demônios-inferno-escravidão... atuando ainda no nosso país.

COMPARAÇÃO DOS MÉTODOS OFICIAIS DE ANÁLISE E CROMATOGRÁFICOS PARA A DETERMINAÇÃO DOS TEORES DE ALDEÍDOS E ÁCIDOS EM BEBIDAS ALCOÓLICAS

OpenAIRE

NASCIMENTO,Ronaldo F.; CERRONI,Jefferson L.; CARDOSO,Daniel R.; LIMA NETO,Benedito Santos; FRANCO,Douglas W.

1998-01-01

É apresentado um estudo comparativo entre os métodos oficiais e cromatográficos para a análise de aldeídos e de ácidos em bebidas alcoólicas. Foram analisadas trinta e cinco amostras de destilados alcoólicos. Com respeito a determinação dos teores totais de aldeídos e de ácidos. Os métodos oficiais e cromatográficos apresentam similar exatidão e reprodutibilidade. Entretanto, apenas os métodos cromatográficos permitem identificar e quantificar os componentes de cada série homologa. As metodol...

¿DOS CULTURAS O DOS PREJUICIOS? UN APORTE PARA LA COMPRENSION

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Edelmira Ochoa Camacho

2015-12-01

Full Text Available Uno de los propósitos explícitos en el proceso de educar debería ser el favorecer la comprensión de la mirada interdisciplinar del conocimiento, que aporte a la formación de personas integrales, curiosas, críticas e imaginativas (Mendoza, Callejas, Porras y Moralejo 2011, y la universidad juega un papel importante en este aspecto. Por lo que esta investigación busca contribuir al acercamiento de las dos culturas, la humanística y la  científico-tecnológica,  separadas  tradicionalmente  por  los  prejuicios  que  han propiciado la incomprensión y el rechazo hacia los otros.  Esta investigación forma parte del Proyecto de Enseñanza y Aprendizaje sobre la Naturaleza de la Ciencia y la Tecnología (EANCYT. En este trabajo se presentan los resultados globales obtenidos en un curso de Electiva interdisciplinar titulado “Consolidación de la cultura científica” de nivel universitario, donde se aplicó una Secuencia de Enseñanza y Aprendizaje (SEA  denominada “¿Dos culturas o dos prejuicios?”, diseñada por Mendoza et al (2011, que tuvo como uno de los objetivos que los estudiantes interpreten las relaciones entre las ciencias y las humanidades con base en la lectura de textos y la discusión con pares. Antes  y  después  de  la  aplicación  de  la  SEA,  se  aplicó  un  test  a  los  estudiantes estructurado  por    6 cuestiones  pertenecientes  al  Cuestionario  de Opiniones  sobre Ciencia-Tecnología-Sociedad, COCTS (Manassero, Vázquez y Acevedo, 2003. Luego de la aplicación de la SEA se obtuvieron mayores índices (que significan opiniones más adecuadas en las cuestiones referidas a unión de dos culturas, valores y estándares, decisiones sociales, ética e instituciones educativas.

Real-time tracking control of electro-hydraulic force servo systems using offline feedback control and adaptive control.

Science.gov (United States)

Shen, Gang; Zhu, Zhencai; Zhao, Jinsong; Zhu, Weidong; Tang, Yu; Li, Xiang

2017-03-01

This paper focuses on an application of an electro-hydraulic force tracking controller combined with an offline designed feedback controller (ODFC) and an online adaptive compensator in order to improve force tracking performance of an electro-hydraulic force servo system (EHFS). A proportional-integral controller has been employed and a parameter-based force closed-loop transfer function of the EHFS is identified by a continuous system identification algorithm. By taking the identified system model as a nominal plant model, an H ∞ offline design method is employed to establish an optimized feedback controller with consideration of the performance, control efforts, and robustness of the EHFS. In order to overcome the disadvantage of the offline designed controller and cope with the varying dynamics of the EHFS, an online adaptive compensator with a normalized least-mean-square algorithm is cascaded to the force closed-loop system of the EHFS compensated by the ODFC. Some comparative experiments are carried out on a real-time EHFS using an xPC rapid prototype technology, and the proposed controller yields a better force tracking performance improvement. Copyright © 2016. Published by Elsevier Ltd.

Electrostaticspray preparation and properties of RDX/DOS composites

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Jian Yao

2017-08-01

Full Text Available A composite explosive based on 1, 3, 5-trinitro-1, 3, 5-triazinane (RDX was prepared by electrostaticspray method with dioctyl sebacate (DOS as desensitizer. After preparation, the particle size and crystal structure were characterized and chemical features, such as chemical bonds, functional groups, thermal decomposition parameters and mechanical sensitivity were investigated as well. In terms of the morphologies of the composites, the particle sizes were in the range of 1–3 μm. Compared with RDX, the crystal types, chemical bonds and functional groups of the RDX/DOS composites were unchanged. The activation energy of the composites was lower than that of raw RDX, and the 3wt % DOS composites had the lowest activation energy. The impact sensitivity and friction sensitivity of the RDX/DOS composites were lower than those of raw RDX, and the 10wt% DOS composites had the highest H50 (125.9 cm and the lowest friction sensitivity (8%.

Overground walking training with the i-Walker, a robotic servo-assistive device, enhances balance in patients with subacute stroke: a randomized controlled trial.

Science.gov (United States)

Morone, Giovanni; Annicchiarico, Roberta; Iosa, Marco; Federici, Alessia; Paolucci, Stefano; Cortés, Ulises; Caltagirone, Carlo

2016-05-26

Patients affected by mild stroke benefit more from physiological overground walking training than walking-like training performed in place using specific devices. The aim of the study was to evaluate the effects of overground robotic walking training performed with the servo-assistive robotic rollator (i-Walker) on walking, balance, gait stability and falls in a community setting in patients with mild subacute stroke. Forty-four patients were randomly assigned to two different groups that received the same therapy in two daily 40-min sessions 5 days a week for 4 weeks. Twenty sessions of standard therapy were performed by both groups. In the other 20 sessions the subjects enrolled in the i-Walker-Group (iWG) performed with the i-Walker and the Control-Group patients (CG) performed the same amount of conventional walking oriented therapy. Clinical and instrumented gait assessments were made pre- and post-treatment. The follow-up observation consisted of recording the number of fallers in the community setting after 6 months. Treatment effectiveness was higher in the iWG group in terms of balance improvement (Tinetti: 68.4 ± 27.6 % vs. 48.1 ± 33.9 %, p = 0.033) and 10-m and 6-min timed walking tests (significant interaction between group and time: F(1,40) = 14.252, p = 0.001; and F(1,40) = 7.883, p = 0.008, respectively). When measured, latero-lateral upper body accelerations were reduced in iWG (F = 4.727, p = 0.036), suggesting increased gait stability, which was supported by a reduced number of falls at home. A robotic servo-assisted i-Walker improved walking performance and balance in patients affected by mild/moderate stroke, leading to increased gait stability and reduced falls in the community. This study was registered on anzctr.org.au (July 1, 2015; ACTRN12615000681550 ).

O manto sagrado de jesus: uma estratégia para a recuperação da cidadania

OpenAIRE

Firmino, Antonio Ricardo Beltrão

2009-01-01

O objeto desta dissertação é o estudo das formas de atendimento dos jovens em situação de risco feitas por três instituições, uma pública laica e duas confessionais, que são Organizações Não Governamentais ONGs - de cunho religioso cristão, sendo uma católica e outra protestante. O objetivo geral desta pesquisa foi: Analisar as formas de atendimento para a recuperação da cidadania e inclusão de jovens em situação de risco social e pessoal de três instituições educacionais, se...

Percepção de valor em uma oferta: o papel dos valores dos consumidores

OpenAIRE

Xavier Júnior, Carlos Eduardo Ramos

2006-01-01

O valor percebido e os valores pessoais dos consumidores são temas que vêm sendo investigados na literatura de marketing por diversos pesquisadores há décadas. Neste sentido, o objetivo desta dissertação foi investigar as relações entre os valores pessoais (KAHLE; KENNEDY, 1989) dos consumidores e a importância atribuída por estes às diversas dimensões do valor percebido apresentadas na literatura (SWEENEY; SOUTAR, 2001). Para isto, definiu-se o público de estudantes universitá...

Abordagem teórica dos condicionantes da formação e consolidação dos parques tecnológicos

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Alexandre Augusto Pereira Gaino

2014-03-01

Full Text Available O artigo discute as condições teóricas para a instalação e consolidação dos parques tecnológicos, mecanismos utilizados na promoção da inovação tecnológica e do desenvolvimento regional, alvo de diversas iniciativas de políticas públicas na atualidade. Para a consecução desse objetivo foi adotada uma abordagem teórica e exploratória, por meio de revisão bibliográfica, em especial de referências internacionais. O artigo apresenta e analisa diversos conceitos e definições de parque tecnológico e constata que essa diversidade decorre das diferentes realidades regionais e das variadas motivações dos stakeholders. O papel dos parques tecnológicos no desenvolvimento regional assume múltiplas feições em decorrência dos distintos interesses dos atores envolvidos em sua instalação. O artigo enfatiza e adverte que há importantes limitações da ideia de que o sucesso do parque depende fundamentalmente da capacidade de cooperação e mobilização de recursos por parte dos agentes envolvidos.

Influência dos valores laborais dos pais sobre os valores laborais dos filhos Parents work values influence on sons work values

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Juliana Barreiros Porto

2006-01-01

Full Text Available Valores laborais são princípios ou metas, hierarquicamente organizadas, que as pessoas buscam e que guiam a sua vida no trabalho. A família, a escola e a experiência de trabalho são apontadas como as variáveis mais influentes na formação dos valores laborais. Os pais são considerados os agentes socializadores mais influentes nesse processo, pois servem como modelo de trabalhador para as crianças. O objetivo do presente trabalho é investigar a influência dos valores paterno e materno nos valores laborais de estudantes universitários. Participaram 129 estudantes universitários, de 17 cursos escolhidos aleatoriamente, seus pais (84 mães e 45 pais e 956 colegas de curso dos estudantes. Os participantes responderam à Escala de Valores Relativos ao Trabalho. Os resultados das regressões hierárquicas indicaram que os pais e os colegas exercem influência sobre os valores laborais de Realização Profissional e Estabilidade dos estudantes. São discutidas a relevância e as limitações desses resultados no artigo.Work values are principles or goals, ordered by importance, that people seek and that guide his/her life at work. Family, school and work experiences are indicated as the most important factors in the formation of work values. Parents are considered the most influential social agent in this process, since they serve as a role model to their children. The present study examines the impact of the work values of parents on the work values of college students. One hundred and twenty nine (129 students and their parents (84 mothers and 45 fathers in 17 randomly chosen undergraduate courses, as well as 956 colleagues of these students participated in this investigation. They answered the Work Values Scale. The results of the hierarchical regressions demonstrated that parents and colleagues influence the student's work values of Professional Achievement and Stability. The relevance and limitations of these results are discussed in

48 CFR 632.702-70 - DOS policy.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false DOS policy. 632.702-70... REQUIREMENTS CONTRACT FINANCING Contract Funding 632.702-70 DOS policy. The Department's policy is to provide... incremental funding of cost-reimbursement contracts. Fixed-price, labor-hour, and time-and-materials contracts...

Considerações gerais sôbre os órgãos odoríferos sexuais dos machos dos Lepidópteros

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Rudolf Barth

1953-12-01

Full Text Available São determinadas as seguintes regras sôbre a função dos órgãos odoríferos dos machos dos Lepidópteros: l.ª regra: A secreção das glândulas age em forma de gás sobre a fêmea diminuindo a reação normal de fuga e provocando a disposição e preparação para a copulação. 2.ª regra: Os órgãos odoríferos nos machos de um grupo de espécies parentes encontram-se constantemente nos mesmos órgãos possuindo o mesmo tipo de estrutura (constância orgânica . 3.ª regra: As partes quitinosas (escamas odoríferas, cerdas distribuidoras, inserções etc. são especificadas para cada espécie (constância de forma. 4.ª regra: O grau de desenvolvimento e com isto o grau de eficiência dos órgãos odoríferos dos Lepidópteros noturnos é sempre mais elevado do que os dos diurnos.

Heterología. La ciencia (imposible de los residuos violentos

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Sergio Tonkonoft

2015-01-01

Full Text Available EI presente trabajo busca mostrar que en la obra de Bataille existe una teoría social general, articulada en torno a la noción de lo sagrado. Nuestra hipótesis es que Bataille profundizó y generalizó d movimiento iniciado por Durkheim, quien postula la sintaxis de lo sagrado arcaico como la parte fundamental de la gramática social, pero interpretando este legado a la luz del concepto de multitud, entendido como el otro nombre de la economía general de las pasiones colectivas. Para dlo, se sirvió de dementos deI psicoanálisis y la fenomenología alemana, produciendo la teoría original dd lazo social, su estructuración y sus dinâmicas, con las que reformuló la idea durkheimniana de lo sagrado y procedió a analizar los malestares de su época. Dada la antropología trágica que enmarcó esta empresa intelectual, resultó de ello la teoría social transgredida o imposible que lleva eI nombre de heterología.

Apuntes de sociología y antropología del arte

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Julio Amador Bech

2006-01-01

Full Text Available En este artículo, el autor analiza el concepto de arte confrontando y cuestionando la oposición y diferencia entre la idea moderna y, con eso, profana, de arte y otra tradicional y antigua, inmersa en la sustancia de lo sagrado. A partir de las definiciones de "arte tradicional" propuestas por diversos autores, se establecen lineamientos teóricos generales para analizar de manera concreta las formas particulares en las que, en diversas culturas, el arte se sitúa al interior de un conjunto de prácticas sociales dentro de complejos mítico-rituales dominados por lo sagrado. Se abordan, en particular, los casos de las culturas prehispánicas del área mesoamericana y el ejemplo de la cultura yoruba de Nigeria. Se desarrolla, asimismo, un esbozo de la génesis del concepto moderno de arte de la Grecia clásica a los orígenes de la modernidad en el Renacimiento, destacando las consecuencias de la secularización del arte moderno y de las formas de ruptura y confrontación entre los conceptos sagrado y profano de arte.

OptaDOS - a new tool for EELS calculations

Science.gov (United States)

Nicholls, R. J.; Morris, A. J.; Pickard, C. J.; Yates, J. R.

2012-07-01

Many modern (Scanning) Transmission Electron Microscopes ((S)TEMs) are equipped with an energy loss spectrometer. The Electron Energy Loss (EEL) spectra collected provide an experimental method of probing the bonding within a material. With the extra addition of monochromators, the energy resolution obtainable means that even more information is revealed within the fine structure of the spectra. Interpreting the fine structure can often be aided by simulation. Density-functional theory (DFT) is one method of simulating EEL spectra. DFT allows us to simulate DOS and EEL spectra from different structures. This comparison between simulation and experiment enables us to explore how changes in the spectrum are related to changes within the sample. CASTEP is a pseudopotential DFT code which can simulate both low-loss and core-loss EEL spectra. Recent developments have resulted in a separate analysis tool, OptaDOS. This package computes various spectral properties including DOS, projected DOS, joint DOS, core-loss and low-loss EEL spectra and optical spectra. One of the important aspects of the code is the way in which the DOS is calculated. This is done via linear extrapolation or adaptive smearing, methods which are not currently available within CASTEP (or indeed any other code) and which allow detailed analysis of spectral properties. This paper summarises these developments and what they mean for the interpretation of EEL spectra.

CRISE E NOVAS EXPRESSÕES DOS MOVIMENTOS POPULARES E SINDICALCRISE E NOVAS EXPRESSÕES DOS MOVIMENTOS POPULARES E SINDICALCRISE E NOVAS EXPRESSÕES DOS MOVIMENTOS POPULARES E SINDICAL

OpenAIRE

Ivo Lesbaupin

1995-01-01

O Brasil tem visto nos últimos tempos o surgimento e desenvolvimento de inúmeros movimentos: movimentos de bairro, movimentos de mulheres, movimento negro, movimento dos atingidos pelas barragens, movimento dos sem-terra, movimento ecológico, e outros. Porque se formam tais movimentos? Qual o alcance, a capacidade de mudança social que têm estes movimentos? Quais as condições para que u m movimento seja bem sucedido?

Disk Operating System--DOS. Teacher Packet. Learning Activity Packets.

Science.gov (United States)

Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

The Learning Activity Packets (LAPs) contained in this manual are designed to assist the beginning user in understanding DOS (Disk Operating System). LAPs will not work with any version below DOS Version 3.0 and do not address the enhanced features of versions 4.0 or higher. These elementary activities cover only the DOS commands necessary to…

Evidências Empíricas sobre a Rentabilidade dos Ativos dos Bancos no Brasil antes da Crise Americana do Subprime

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Fernando da Silva Vinhado

2014-12-01

Full Text Available Segundo a visão pós-keynesiana, defendida por Tobin (1982, os ativos dos bancos são divididos basicamente entre aqueles de natureza defensiva, representados fundamentalmente por títulos financeiros, com característica de maior liquidez e menor rentabilidade, e as operações de crédito, que são ativos não defensivos com perfil de oferecer menor liquidez e maior rentabilidade. Com base nessa visão e a partir de dados organizados em painel, contemplando 71 instituições financeiras que atuaram no Brasil entre 2000 e 2008, no presente artigo foi utilizada a técnica econométrica do método dos momentos generalizados em sistema (GMM-SYS a fim de analisar empiricamente a influência de variáveis macro e microeconômicas sobre a rentabilidade de ativos dos bancos no país, tanto em títulos financeiros quanto em operações de crédito. Os exercícios econométricos propostos, que objetivaram melhorar a compreensão em relação à formação da rentabilidade dos ativos dos bancos no mercado bancário brasileiro, permitiram identificar aspectos como a persistência nos níveis de rentabilidade, a nacionalidade e personalidade jurídica dos bancos mais rentáveis por tipo de ativo, a influência do tamanho da instituição e do nível de capitalização sobre a rentabilidade dessas aplicações, além das evidências contrárias à hipótese de estrutura-conduta-performance (HCP no mercado bancário brasileiro. As estimativas envolvendo as variáveis macroeconômicas revelaram influência positiva da taxa básica de juros e característica pró-cíclica da rentabilidade dos ativos bancários. Assim, os achados permitem melhor decifrar o comportamento do desempenho dos ativos das instituições financeiras no Brasil, o que pode, inclusive, vir a orientar esforços de gestão e supervisão no sistema financeiro.

Evidências Empíricas sobre a Rentabilidade dos Ativos dos Bancos no Brasil antes da Crise Americana do Subprime

Directory of Open Access Journals (Sweden)

Fernando da Silva Vinhado

2014-11-01

Full Text Available Segundo a visão pós-keynesiana, defendida por Tobin (1982, os ativos dos bancos são divididos basicamente entre aqueles de natureza defensiva, representados fundamentalmente por títulos financeiros, com característica de maior liquidez e menor rentabilidade, e as operações de crédito, que são ativos não defensivos com perfil de oferecer menor liquidez e maior rentabilidade. Com base nessa visão e a partir de dados organizados em painel, contemplando 71 instituições financeiras que atuaram no Brasil entre 2000 e 2008, no presente artigo foi utilizada a técnica econométrica do método dos momentos generalizados em sistema (GMM-SYS a fim de analisar empiricamente a influência de variáveis macro e microeconômicas sobre a rentabilidade de ativos dos bancos no país, tanto em títulos financeiros quanto em operações de crédito. Os exercícios econométricos propostos, que objetivaram melhorar a compreensão em relação à formação da rentabilidade dos ativos dos bancos no mercado bancário brasileiro, permitiram identificar aspectos como a persistência nos níveis de rentabilidade, a nacionalidade e personalidade jurídica dos bancos mais rentáveis por tipo de ativo, a influência do tamanho da instituição e do nível de capitalização sobre a rentabilidade dessas aplicações, além das evidências contrárias à hipótese de estrutura-conduta-performance (HCP no mercado bancário brasileiro. As estimativas envolvendo as variáveis macroeconômicas revelaram influência positiva da taxa básica de juros e característica pró-cíclica da rentabilidade dos ativos bancários.  Assim, os achados permitem melhor decifrar o comportamento do desempenho dos ativos das instituições financeiras no Brasil, o que pode, inclusive, vir a orientar esforços de gestão e supervisão no sistema financeiro.

Análise da lucratividade dos clientes

OpenAIRE

Madeira, Paulo

2000-01-01

Um bom sistema de Análise da lucratividade de Clientes pode ajudar a melhorar a rendibilidade global do negócio, selecionando os clientes de qualidade, e a indicar o principal caminho a segui rpara atingir uma maior lucartividade, indicando o impacto financeiro actual e potencial dos movimentos estratégicos dos clientes.

Incidente com Jornalistas portugueses no Iraque. Imprudência ou espírito missionário? A batalha dos argumentos nas colunas dos jornais

OpenAIRE

Oliveira, Madalena

2007-01-01

O chamado jornalismo de guerra é, desde o desenvolvimento de tecnologias que permitiram o relato de conflitos em directo, um dos tópicos mais estimulantes do debate em torno dos escolhos e dos desafios do ofício daqueles que têm por missão informar. Os riscos associados às movimentações dos jornalistas em campos de bata-lha são, com frequência, o fermento de notícias que enchem secções especializadas nos media. O baleamento de uma jornalista da SIC e o sequestro de um repórter da TSF, no Iraq...

Zumbi dos Palmares: a afroresiliencia

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Josué Petrônio Quirino de Oliveira

2017-10-01

Full Text Available O artigo buscou fazer uma releitura de Zumbi dos Palmares sob o prisma da resiliência, demonstrando uma visão singular ao olhar para os escravos nos quilombos e suas histórias de superação e transformação perante as adversidades, levando não só a reconstruir o imaginário afrodescendente brasileiro com o caleidoscópio da resiliência, mas revelar que a resiliência sempre foi inerente a história dos negros no Brasil. Para tanto se caracterizou como uma pesquisa exploratória com abordagem qualitativa e procedimentos bibliográficos que foram essenciais para a construção do artigo, amadurecendo e ampliando os conhecimentos envolvidos na temática. Nesta abordagem o quilombo dos Palmares foi um conjunto complexo de condições, atitudes e ações que apesar das adversidades tiveram resultados positivos, os fatos demonstraram que os negros nos quilombos foram uma prova que a resiliência negra não foi apenas um fator individual, mas uma característica comunitária que desencadeou um processo de ruptura e recuperação social, um grito de liberdade em defesa da consciência de uma raça, e de um povo. Zumbi não foi apenas um líder de um movimento libertário que marcou a história dos negros oriundos de Pernambuco e Alagoas, mas a história de uma raça por gerações no país, que se tornou sinônimo de resiliência.

Atividades Física, Educativa e de Dança: Um Estudo dos Valores Pessoais dos Consumidores Idosos

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Luciana Torres Souza Kelly

2012-02-01

Full Text Available Este artigo apresenta como objetivo principal identificar os valores pessoais dos consumidores idosos dos serviços de atividades física, educativa e de dança, sob o aspecto motivacional hedônico e utilitário. Adotou-se o modelo de cadeia meios-fim de Gutman (1982, o qual sugere que a pesquisa deve utilizar uma abordagem qualitativa através da entrevista em profundidade no levantamento dos dados e da análise de conteúdo. Uma fase da metodologia é quantitativa, decorrente da tabulação das conseqüências e valores em tabelas, visando construir os mapas hierárquicos, os quais se constituem em diagramas de freqüência. Por meio dos resultados indicados nos mapas hierárquicos de valor foi possível observar que os valores e benefícios associados à participação em cada atividade são tanto de interesse individual quanto coletivo, e tanto de natureza hedônica quanto utilitária. Constatou-se através dos resultados, a identificação de valores convergentes e divergentes apontando o perfil heterogêneo do consumidor idoso indicando que a cultura, as vivências, as experiências e as realidades atuais corroboram para a manifestação de um valor pessoal característico na sua vida. E nas situações de compra e utilização de serviços, apresentam como meta a aquisição de novas amizades e a experimentação de momentos variados (com novidades na vida diária. DOI: 10.5585/remark.v10i3.2251

ESCRITORAS BAIANAS DOS OITOCENTOS ENFRENTANDO PRECONCEITOS

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Helena Parente Cunha

2017-05-01

Full Text Available Tem sido a conquista dos últimos anos o reconhecimento das autoras brasileiras dos séculos passados, mias numerosas do que se supunha e que foram esquecidas devido aos preconceitos do canone Literário. A partir da segunda metade do século XIX, com o levantamento dos períodos em todo o país, dirigidos e editados por mulheres e para mulheres, veiculavam as ideias avançadas e, ao mesmo tempo, concepções do sistema patriarcado. O medo do corpo e do erotismo se transmite à produção literária feminina que, ao se inspirar no amor, quase sempre usa linguagem pudica, procuando santificar o sentimento. Mas não raro surgem passagens de uma audácia inesperada, num desafio ostensivo aos convencionalizmos do cânone comportamental. Estudam-se como as escritoreas Ana Ribeiro, Ildefonsa Laura César e Adelio Fonseca, dentro deste contexto

Estudio de inmunogenicidad para dos vacunas recombinantes contra hepatitis B

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O. Juliao

1991-12-01

Full Text Available Este estudio compara la inmunogenicidad (seroconversión, seroprotección e Hiperrespuesta, producida por dos vacunas recombinantes contra la hepatitis B (Engerix-B de Bélgica y Cubana, en dos esquemas (012 y 016 meses, empleando los métodos de cuantificación para Anti-HBsAg (Abbott y Organón, los cuales fueron también comparados. En el estudio participaron 257 voluntarios,  divididos al azar en 4 grupos (dos vacunas, dos esquemas. Resultados: los dos métodos de Abbon y Organon, no presentan diferencias estadísticas significativas. La vacuna cubana muestra una mayor respuesta inmunogénica para dos dosis de vacuna y para el esquema 012. No hay diferencia entre los esquemas 012 y 016 y en el esquema 016 no se ven diferencias estadísticamente significativas con la vacuna Engerix-B. En esta Última el esquema 016 muestra mejores resultados que el 012.

PADRONIZAÇÃO DA SÍNTESE DOS PRINCIPAIS CONSTITUINTES FEROMONAIS DE INSETOS DOS GÊNEROS METAMASIUS E RHYNCHOPHORUS

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JOHNNATAN DUARTE DE FREITAS

2011-05-01

Full Text Available Os curculionídeos são insetos que causam grandes problemas econômicos aos agricultores e atingem culturas, como coco, dendê, cana-de-açúcar, milho, banana, algodão, etc. O controle de pragas agrícolas, ainda hoje, utiliza grandes quantidades de inseticidas, que são prejudiciais à saúde dos animais, do homem e do meio ambiente. Uma alternativa ao uso desses inseticidas é o uso de feromônios, por serem mais seletivos e menos tóxicos. Nesse trabalho, descrevemos a síntese, em escala preparativa, dos compostos (±-5-Nonanol, (±-2-Metil-4-octanol, (±-2-Metil-4-heptanol, (±-3-Metil-4-octanol, (±-5-Metil-4-octanol, (±-4-Metil-5-nonanol, (±-6-Metil-2-hepten-4-ol, 2-Metil-4-octanona, 2-Metil-4-heptanona e (±-4-Metil-5-nonanona, principais constituintes feromonais de alguns insetos dos gêneros Metamasius e Rhynchophoruseas. A síntese consistiu na reação de Grignard entre um aldeído e um brometo de alquilmagnésio. As oxidações dos álcoois para obtenção das cetonas foram realizadas com hipoclorito de sódio.

Números primos: os átomos dos números

OpenAIRE

Rigoti, Marcio Dominicali

2015-01-01

Este trabalho apresenta um estudo sobre os Números Primos que passa por resultados básicos, como a infinitude dos números primos e o Teorema Fundamental da Aritmética, e resultados mais sofisticados, como o Teorema de Wilson e a consequente função geradora de primos. Além dos resultados teóricos apresenta-se uma interpretação geométrica para os números primos. Essa interpretação e aplicada na ilustração de alguns dos resultados relacionados a primos abordados no ensino básico. Atividades envo...

Efeitos deleterios dos cloretos em reservatorios de concreto

OpenAIRE

Matoski, Adalberto

1998-01-01

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnologico Caracterização dos reservatórios de água potável das regiões de Curitiba e Florianópolis, quanto às patologias apresentadas. Utilização do ensaio de potencial de eletrodo para a definição das linhas equipotenciais sobre a laje de concreto dos reservatórios. Análise dos efeitos do cloro adicionado à água, para sua desinfecção, sobre o concreto. Comparaçao entre os ensaios químico e de espectrometria de raio...

Iconoclasmo e iconodulia entre oriente y occidente (siglos VIII-IX Iconoclasm and iconoduly between east and west (8th-9th centuries

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Alfonso Hernández Rodríguez

2011-10-01

Full Text Available El siguiente artículo trata acerca de la recepción en el occidente carolingio de la crisis iconoclasta. Reflexiona sobre la forma en que ambas cristiandades trataron el problema que las imágenes representan para las prácticas religiosas y las consecuencias políticas del culto de los iconos. El escrito afirma también que durante los siglos VIII y IX la crisis iconoclasta permitió la aparición de una tradición cristiana latina consciente de sí misma. Por lo tanto, se trató del momento que puso en evidencia el nacimiento de dos formas divergentes de piedad cristiana y la alienación de una respecto de la otra. La cristiandad occidental centrada en el edificio eclesiástico y que privilegiaba la ubicación de lo sagrado en el rito eucarístico, y la oriental cuyo centro era la adoración de las imágenes, con la consecuente multiplicación de los espacios sagrados.The following paper deals with the reception in the Carolingian west of the Byzantine Iconoclast Crisis. It considers the way both Christianities dealed with the problem that images presented to religious practices and the political consequences of iconic worship. The paper also states that during the VIII and IX centuries the iconoclast crisis allowed the emergence of a self conscious Latin Christian tradition. Consequently it was the moment that showed the beginning of two differing ways of Christian piety and the alienation of one towards the other. Western Christianity focused its religion practice in church building and the idea of Sacrality in the Eucharistic Rite. The oriental church, moreovers, centered its practices and theology on icon worship.

O legado dos desenhadores da guerra

OpenAIRE

Almeida, Reginaldo Rodrigues de

2017-01-01

O comportamento que causa dano ou prejuízo moral é um comportamento violento, logo temido. Porém, não se foge dele, antes se procura.Verifica-se uma avidez global em busca de imagens,sejam fotografias ou vídeos, tendo a fotografia do interior da casa de espectáculos parisiense Le Bataclan, com os cadáveres dos reféns,ainda que pouco perceptível, sido vista até à exaustão, na sequência dos ataque terroristas dodia 13 de Novembro de 2015 em Paris.

Repercussões da aceleração dos ritmos de trabalho na saúde dos servidores de um juizado especial

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Daiane Dal Pai

2014-09-01

Full Text Available Os recentes incrementos tecnológicos promovidos junto ao serviço judiciário federal trouxeram avanços importantes para a melhoria dos atendimentos prestados à população, contudo originaram novas demandas organizacionais aos trabalhadores do setor. Objetivo Conhecer as repercussões da organização do trabalho no cotidiano laboral e na saúde dos servidores do Juizado Especial Federal de Porto Alegre (RS.Procedimentos metodológicos Desenvolveu-se uma pesquisa de abordagem qualitativa, por meio de entrevistas semiestruturadas com 17 servidores de um juizado especial federal. As falas foram gravadas em áudio, transcritas e submetidas à análise de conteúdo. O referencial teórico da psicodinâmica do trabalho fundamentou a interpretação dos achados.Resultados Foram identificadas duas categorias de análise: (1 Mudanças na organização do trabalho: de processos judiciais físicos à aceleração virtual e (2 Adaptação dos profissionais às mudanças e suas repercussões sobre a saúde. Na primeira categoria foram discutidas as transformações vivenciadas pelos trabalhadores a partir da implantação dos sistemas informatizados de recebimento e análise dos processos judiciais. Na segunda categoria revelaram-se as exigências psíquicas e físicas que os trabalhadores associaram ao contexto laboral.Conclusão Concluiu-se que os trabalhadores se percebem diante de um ritmo acelerado e elevado volume de trabalho, convivendo com sintomas que sugerem o adoecimento e sentindo-se desassistidos quanto às mudanças estabelecidas ao processo de trabalho.

Bibliotecas: metáforas da memória Libraries: memory metaphors

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Terezinha Elisabeth da Silva

2006-01-01

Full Text Available Analisa o desejo de acúmulo do saber e da memória e, o desejo de mostração do poder representados na arquitetura dos prédios de grandes bibliotecas. A biblioteca como metáfora da memória da humanidade. Discute sobre o sonho do eterno que perpassa os desejos das bibliotecas ao longo da história do livro e das bibliotecas. Reflete sobre a função dos prédios (edifícios de grandes e importantes bibliotecas para o desenvolvimento e manutenção do desejo do eterno e da metáfora da memória e a representação do fantástico e do sagrado.It analyzes the desire of knowledge and memory accumulation and the desire of showing power represented by the architecture of great library buildings. The library as metaphor of human memory. It discusses the dream of eternal that are in libraries along books and library history. Reflexions on the funcion of great and important libraries for the development and maintenance of the desire of eternal and the metaphor of the memory and the representation of the fantastic and of the consecreated.

ESTUDO DOS PRINCÍPIOS APLICADOS À UTILIZAÇÃO DOS AGENTES QUÍMICOS DESINFETANTES HOSPITALARES

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Vanda M. Galvão Jouclas

Full Text Available As autoras realizaram um levantamento bibliográfico coletando dados atualizados sobre a utilização dos agentes químicos desinfetantes hospitalares, levando-se em consideração suas possibilidades e suas limitações. São abordados na fundamentação científica o conceito de desinfecção e esterilização, as condições necessárias para a ação efetiva de um agente químico, os critérios de escolha do agente químico, e a classificação dos agentes químicos utilizados em equipamentos e materiais médico-cirúrgicos.

Análise e Mapeamento sobre a Avaliação da Evidenciação dos Atos Públicos dos Entes Governamentais

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Lucas dos Santos Matos

2015-08-01

Full Text Available O aumento da demanda da população e dos órgãos fiscalizadores por informações relacionadas à gestão governamental ocasionou a necessidade de melhorar a evidenciação dos relatórios públicos, tanto na abrangência e qualidade da informação quanto na sua transparência. Surge então a necessidade de desenvolver modelos de avaliação da transparência dos atos públicos que contemplem a necessidade dos usuários. Assim, esta pesquisa, de natureza exploratório-descritiva, com abordagem qualitativa e quantitativa, objetiva realizar um mapeamento sobre o tema avaliação da evidenciação dos atos públicos dos entes governamentais a partir da seleção de um rol de artigos internacionais reconhecidos cientificamente e, a partir deste portfólio, realizar uma análise de conteúdo destes artigos, visando à identificação de oportunidades de pesquisas. Dessa forma, foi selecionado o Knowledge Development Process – Constructivist (ProKnow-C como instrumento de intervenção do processo. O resultado foi um conjunto de 14 artigos científicos, publicados entre 2000 e 2013, com reconhecimento e, para estes artigos, evidenciou-se os principais artigos, periódicos, autores e palavras-chave acerca do tema de estudo. A análise de conteúdo possibilitou encontrar destaques e oportunidades para pesquisas futuras. Verificou-se que a literatura trata apenas de modelos de avaliação da transparência pública conforme os critérios definidos por normas e legislações, mas é necessário considerar as necessidades dos usuários.

A proteção dos deslocados ambientais no regime internacional dos refugiados

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Andrea Pacheco Pacífico

Full Text Available O deslocamento de pessoas por causas ambientais gera discussões pela ausência de reconhecimento legal e proteção jurídica específica para essa categoria de pessoas. Assim, este artigo examina o Regime Internacional dos Refugiados (RIR, conceitua deslocados ambientais (DA e reflete sobre a ausência de proteção pelo RIR. Em seguida, examina as causas e as consequências dos deslocamentos e as formas de proteção aos DA, concluindo que os regimes vigentes não lhes oferecem proteção efetiva. Uma solução, segundo Betts (2009, seria cooperação para proteção por persuasão via cruzamento de assuntos de interesse estatal, persuadindo Estados a cooperarem em seus interesses, como saída eficaz para a ausência de proteção efetiva aos DA.

A Proposal Of Simulation Model Of A Wind-Steering System For Sailing Yachts, Based On Single-Stage Servo-Pendulum Coupled With Main Rudder

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Piętak Andrzej

2015-04-01

Full Text Available The aim of this study was to investigate possible application of fast design prototyping methods for wind-steering systems used in offshore sailing yachts. The development of such methods would help to speed up the construction work and reduce the scope of necessary experimental research, prior to implementation of the system. In the present work, based on an analysis of existing designs of windvane systems, a preliminary selection of the system configuration has been undertaken, in terms of a compromise between efficiency, performance, and design complexity. Construction design of a single-stage, servo – pendulum system, has been developed by using the Autodesk Inventor design package. Next, based on the design data, a simulation model of the system, has been produced by using Matlab - Simulink software and SimMechanics library. The model was further verified in terms of kinematics mapping with the use of Matlab visualization tools.

EDITORIAL: Plágio e ineditismo dos artigos

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Fernando Castro Amoras

2016-06-01

Full Text Available EDITORIAL: Plágio e ineditismo dos artigos A partir deste ano de 2016, a revista Estação Científica (UNIFAP passou a adotar, como instrumento auxiliar da seleção dos artigos que serão publicados, a checagem de plágio nos conteúdos dos trabalhos que recebemos. Consta no site da revista a informação de que todos os trabalhos passarão por verificação de plágio, e desta forma alerta-se que sejam apresentados à Estação Científica (UNIFAP apenas os trabalhos que tenham autenticidade de autoria.

Estátuas, um mysterium tremendum, em Cecília Meireles e Dora Ferreira da Silva

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Enivalda Nunes Freitas e Souza

2011-12-01

Full Text Available Este artigo aproxima a temática da estatuária nas poéticas de Dora Ferreira da Silva e Cecília Meireles, explorando o simbolismo da pedra relacionado à morte e a alma das coisas na forma fria das estátuas. Nos poemas dessas autoras, as imitações da pedra evocam o mysterium tremendum. Mensageiras do sagrado intocável que incita e invade o reino dos mortais, as estátuas parecem resistir à vida aprisionada no mármore com seu tanto de terrífico e fascinante que ponteia o divino e o humano. Daí a recorrência das poetas a esse simbolismo – que imita a vida sem ter vida – como uma forma de diminuir a intensidade de um mistério que só os deuses conhecem, o sentido da eternidade.Palavras-chave: Poesia brasileira; Cecília Meireles; Dora Ferreira da Silva; Estatuária; Mysterium tremendum.

LÁ VEM A BANDEIRA... OS REIS E SEUS ATORES

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Mauro Passos

2011-01-01

Full Text Available A religiosidade popular manifesta-se por meio de rituais, festas, comemorações e celebrações. Alicerçadas em elementos místicos, as tradições populares integram o natural, o social e o sagrado. Este artigo faz um estudo das “Folias de Reis”, particularmente em duas cidades do interior de Minas Gerais. Foram utilizados os procedimentos metodológicos da história oral, através de um conjunto de depoimentos. A religiosidade faz parte da cultura das classes populares. Seu estudo é um importante instrumento para a compreensão das raízes culturais e históricas do povo brasileiro. Na verdade, trata-se do mundo de Deus e mundo dos homens, ancorados no rio da vida. As Folias de Reis estão permeadas por múltiplos atores, lastreadas de continuidades / descontinuidades. Em vista disso, é necessário analisar seu significado e sua dinâmica.

AVALIAÇÃO DA EFICIÊNCIA DA APLICAÇÃO DOS ROYALTIES DA MINERAÇÃO NO DESENVOLVIMENTO SOCIAL DOS MUNICÍPIOS MINEIROS

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Alexandre de Cássio Rodrigues

2016-12-01

Full Text Available Tendo os royalites da mineração como origens de recursos públicos dos municípios nos quais a atividade mineral ocorre, essa pesquisa tem como objetivo analisar, por meio de indicadores sociais, se a aplicação dos royalties da mineração tem impactado positivamente no desenvolvimento dos municípios mineiros. Para tanto, utilizou-se na pesquisa documental a prestação de contas anual das prefeituras e câmaras municipais, informações sobre população municipal no site do IBGE e obtido o Índice Firjan de Desenvolvimento Municipal, sendo posteriormente utilizadas técnicas de regressão linear e análise de clusters. Os resultados indicam que o aumento da dependência dos royalties da mineração implica na redução do desenvolvimento humano dos municípios de base mineral. Além disso, não foram encontradas evidências de que a atividade mineral proporcione altos níveis de geração de emprego e distribuição de renda. Portanto, é necessário que esses recursos sejam geridos de forma mais eficiente, priorizando-se projetos que estimulem a diversificação econômica dos municípios.

Das bruxas, dos índios, dos negros e dos jovens da Febem

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Sylvia Leser de Mello

2001-01-01

Full Text Available Este artigo visa discutir os temas Pesquisa e Direitos Humanos, partindo da definição do que pretende a Ciência, suas limitações e momentos seus a serviço de condenações de bruxas e ateus. Trata-se de levantar a questão da 'parcialidade' da Ciência e das formas de exclusão que ela ajudou a gerar e manter face aos criminosos, aos loucos, aos negros e, sem dúvida, aos jovens das camadas populares que são institucionalizados na FEBEM. E, na tentativa de resistência a se deixar levar pelo que de nefasto existe na mercantilização da Ciência hoje, buscar radicalizar a exigência de defesa dos Direitos Humanos.

COMPARAÇÃO DOS MÉTODOS OFICIAIS DE ANÁLISE E CROMATOGRÁFICOS PARA A DETERMINAÇÃO DOS TEORES DE ALDEÍDOS E ÁCIDOS EM BEBIDAS ALCOÓLICAS

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NASCIMENTO Ronaldo F.

1998-01-01

Full Text Available É apresentado um estudo comparativo entre os métodos oficiais e cromatográficos para a análise de aldeídos e de ácidos em bebidas alcoólicas. Foram analisadas trinta e cinco amostras de destilados alcoólicos. Com respeito a determinação dos teores totais de aldeídos e de ácidos. Os métodos oficiais e cromatográficos apresentam similar exatidão e reprodutibilidade. Entretanto, apenas os métodos cromatográficos permitem identificar e quantificar os componentes de cada série homologa. As metodologias propostas utilizando as técnicas de cromatografia gasosa e cromatografia líquida são simples, rápidas e apresentam maior sensibilidade que os métodos oficiais sendo aplicáveis também a amostras coloridas.

Influência da forma dos agregados miúdos nas propriedades do concreto

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F. Fabro

Full Text Available Os agregados miúdos utilizados na produção de concretos são basicamente as areias naturais provenientes dos leitos dos rios e os agregados artificiais oriundos da britagem de rocha. A principal diferença entre estes dois agregados está no formato de seus grãos. O objetivo principal deste trabalho é avaliar o formato dos grãos de agregados miúdos por meio de diferentes parâmetros, analisando as diferenças entre as formas dos agregados, e suas conseqüências nas propriedades das argamassas e concretos confeccionadas com estes materiais. Para medição dos grãos dos agregados empregou-se a análise digital de imagens e foram calculados os seguintes parâmetros: relação de aspecto, esfericidade, indicador de lamelaridade e coeficiente de forma, sendo que os dois últimos foram os que melhor avaliaram a forma dos agregados. Observou-se que o formato dos grãos dos agregados artificiais depende do tipo de britador empregado pelas pedreiras no processo de britagem das rochas. Os agregados oriundos do britador do tipo vertical de impacto possuem grãos mais arredondados, semelhantes aos grãos da areia natural. Verificou-se que o formato dos grãos dos agregados tem influência direta sobre a consistência das argamassas e concretos, porém não apresentou influência nos resultados de resistência à compressão.

Isotopic and chemical investigations on Angra dos Reis

International Nuclear Information System (INIS)

Wasserburg, G.J.; Tera, F.; Papanastassiou, D.A.; Huneke, J.C.

1977-01-01

Extensive isotopic studies of Pb, Sr and Xe and chemical abundance measurements of K, Rb, Sr, Ba, Nd, Sm, U and Th for total meteorite and mineral separates of the Angra dos Reis achondrite are reported on. U-Pb, Th-Pb and Pb-Pb ages are concordant at 4.54 AE for the total meteorite and for high-purity whitlockite in Angra dos Reis. This establishes Angra dos Reis as an early planetary differentiate which has not been disturbed for these systems since 4.54 AE ago. Measured 87 Sr/ 86 Sr in pyroxene and whitlockite for Angra dos Reis (ADOR) are distinctly below BABI by two parts in 10 4 and only one part in 10 4 above the lowest 87 Sr/ 86 Sr (ALL) measured in an Allende inclusion. The difference in ADOR-ALL corresponds to an interval of condensation in the solar nebula of approximately 3 m.y. If 26 Al was the heat source for the magmatism on the parent planets of Angra dos Reis and the basaltic achondrites (BABI) then the relatively large difference in 87 Sr/ 86 Sr, BABI - ALL, must be the result of planetary evolution rather than condensation over approximately 10 m.y. Xe isotopic measurements confirm the presence of large amounts of 244 Pu-produced fission Xe and show that 244 Pu was enriched in the whitlockite relative to the pyroxene by a factor of approximately 18. Chemical element enrichment factors between the whitlockite and the fassaitic pyroxene in Angra dos Reis are presented. The enrichment factors demonstrate close analogy between the rare earth elements and their actinide analogs. The enrichment factor for Pu is intermediate to the enrichment factors of Nd and Sm. (Auth.)

A prática de enfermagem em uma Unidade de Queimados: análise dos discursos dos enfermeiros

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Lídia Aparecida Rossi

1994-06-01

Full Text Available Este estudo teve como objetivo analisar a prática de enfermagem em uma Unidade de Queimados. Essa análise foi realizada a partir dos depoimentos de enfermeiros dessa Unidade, obtidos em um estudo anterior através de técnica de observação participante e de registro cursivo(19. Concluímos que os enfermeiros estão insatisfeitos com os salários, com a jornada de trabalho, com o relacionamento médico-enfermeiro e com as situações que envolvem o sofrimento e a agressividade dos pacientes. O cuidado direto parece consistir em uma fonte de satisfação, mas o enfermeiro está dividido entre a realização desse cuidado e os problemas que têm que resolver. O planejamento da assistência foi ajustado às rotinas do serviço e não às necessidades dos pacientes.

Nonlinear Dynamic Modeling of a Supersonic Commercial Transport Turbo-Machinery Propulsion System for Aero-Propulso-Servo-Elasticity Research

Science.gov (United States)

Connolly, Joe; Carlson, Jan-Renee; Kopasakis, George; Woolwine, Kyle

2015-01-01

This paper covers the development of an integrated nonlinear dynamic model for a variable cycle turbofan engine, supersonic inlet, and convergent-divergent nozzle that can be integrated with an aeroelastic vehicle model to create an overall Aero-Propulso-Servo-Elastic (APSE) modeling tool. The primary focus of this study is to provide a means to capture relevant thrust dynamics of a full supersonic propulsion system by using relatively simple quasi-one dimensional computational fluid dynamics (CFD) methods that will allow for accurate control algorithm development and capture the key aspects of the thrust to feed into an APSE model. Previously, propulsion system component models have been developed and are used for this study of the fully integrated propulsion system. An overview of the methodology is presented for the modeling of each propulsion component, with a focus on its associated coupling for the overall model. To conduct APSE studies the described dynamic propulsion system model is integrated into a high fidelity CFD model of the full vehicle capable of conducting aero-elastic studies. Dynamic thrust analysis for the quasi-one dimensional dynamic propulsion system model is presented along with an initial three dimensional flow field model of the engine integrated into a supersonic commercial transport.

SATISFAÇÃO DOS CLIENTES: UMA ANÁLISE DA QUALIDADE DOS SERVIÇOS PRESTADOS POR UM HOSPITAL DO NORTE FLUMINENSE

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PIANNA, L M

2015-12-01

Full Text Available A satisfação dos clientes demonstra a qualidade nos serviços prestados pela organização. O atendimento é atualmente um dos assuntos mais importantes e pesquisados pelas instituições hospitalares que almejam prestar um serviço de melhor qualidade aos seus pacientes. Segundo Kotler (1998, p. 53 algumas das empresas mais bem-sucedidas de hoje estão aumentando as expectativas dos consumidores e melhorando suas condições de atendimento por meio das pesquisas de satisfação. A satisfação do cliente é um dos principais indicadores da qualidade no atendimento à saúde, por isso a importância de analisar o bem-estar dos usuários em relação aos serviços que lhe são oferecidos é de extrema importância. Com base neste contexto, a avaliação dos serviços prestados sobre percepção dos usuários, transformou-se em uma ferramenta fundamental para os tomadores de decisão. A administração deste tipo de serviço é um processo complexo, cheio de subjetivismo, envolvem valores, experiências dentre outros aspectos. Para Las Casas (2008, p.62 as empresas voltadas para o cliente devem priorizar as pesquisas dos consumidores. Assim, é possível conhecer as atuais necessidades e desejos, ou então identificar os níveis de satisfação que o consumidor em relação à empresa. Empresas com foco no cliente desenvolvem práticas permanentes para identificar suas necessidades. A compreensão das expectativas e necessidades dos clientes facilita a empresa aderir a procedimentos que correspondem a essas necessidades. Entretanto, o objetivo principal deste estudo é identificar o nível de satisfação dos clientes com base na metodologia servqual em um hospital do Norte Fluminense. Para atender o objetivo geral deste estudo, foram propostos os seguintes objetivos específicos: construir referencial teórico sobre qualidade em serviços; elencar dimensões do modelo servqual para avaliação da qualidade em serviço; apontar possíveis perdas

Solubilidade e disponibilidade dos micronutrientes em fertilizantes

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F. Vale

1999-06-01

Full Text Available A legislação brasileira exige que os micronutrientes nos fertilizantes sejam garantidos pelo teor total presente. Isto abre um precedente para a utilização de produtos não considerados como fontes de micronutrientes na fabricação dos fertilizantes. Todavia, a eficiência agronômica desses produtos é ainda duvidosa. Objetivou-se realizar um trabalho para caracterizar a solubilidade e a disponibilidade dos micronutrientes em trinta fertilizantes comerciais, por meio do uso de cinco extratores químicos: a água e soluções de ácido cítrico a 2%, de citrato neutro de amônio na diluição 1 + 9, de DTPA 0,005 mol L-1 e de EDTA 0,005 mol L-1. Os resultados mostraram a baixa solubilidade dos micronutrientes metálicos (cobre, ferro, manganês e zinco dos fertilizantes tipo "fritas". O ácido cítrico a 2% mostrou-se promissor na caracterização da disponibilidade de cobre, manganês e zinco para as plantas. Para o ferro não houve uma definição entre os extratores estudados. O boro teve boa solubilidade, tanto nos fertilizantes solúveis, como nos insolúveis em água, e a garantia pelo teor total mostrou-se bom indicativo da disponibilidade do elemento. Para o molibdênio a solubilidade foi maior para os fertilizantes com baixo teor do elemento. A garantia dos micronutrientes catiônicos pelo teor total, conforme exige a legislação, não indicou a sua real disponibilidade nos fertilizantes comerciais, mostrando a necessidade de uma definição de extratores para esse fim.

ANÁLISE DO IMPACTO DOS ROYALTIES DO PETRÓLEO NO DESENVOLVIMENTO LOCAL DOS MUNICÍPIOS POTIGUARES

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Ridalvo Medeiros Alves de Oliveira

2009-12-01

Full Text Available Os royalties do petróleo são compensações financeiras consequentes da exploração de petróleo ou gás natural. Devido à relevância da receita dos royalties do petróleo para a política fiscal e de desenvolvimento econômico do Rio Grande do Norte, e em particular, para os municípios que compõem a Área de Petróleo Potiguar, se fez necessário estabelecer um estudo sobre as suas influências na dinâmica socioeconômica dessa região. O objetivo geral desse artigo é investigar as contribuições das receitas extraordinárias, originadas da atividade industrial de petróleo no território potiguar, para a melhoria da qualidade de vida destes municípios. Assim, através da evolução dos índices de IDH-M vislumbrou-se observar se os royalties têm contribuído para o desenvolvimento humano nos municípios em estudo. Os dados para a pesquisa foram obtidos junto ao IBGE, ANP e FERMURN, e para analisar aevolução das duas variáveis – royalties e IDH-M – foi utilizada a metodologia descritiva. Ao final do artigo conclui-se que um dos fatores que ocasionaram na melhoria da dinâmica de desenvolvimento dos municípios da região foi o incremento dessa receita extraordinária nosorçamentos municipais, permitindo investimentos em programas que possibilitaram melhoria nas variáveis: renda, longevidade e educação. O resultado do coeficiente de Pearson (0,689apresentou que existe uma correlação positiva entre as variáveis no período de 1995 a 2000.

Geoeconomia dos emergentes

OpenAIRE

Pinto, Pedro

2010-01-01

Mercados decisivos para a recuperação da economia global, até porque muito mais imunes às consequências da crise fi nanceira, os países emergentes apresentam taxas de crescimento mais altas face aos principais países desenvolvidos e têm desempenhado um papel fundamental na consolidação dos volumes de comércio internacional e de crescimento da economia mundial ao longo desta última década.

Satisfação e percepção dos usuários dos sistemas de saneamento de municípios goianos operados pelas prefeituras

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Aline Souza Carvalho Lima

Full Text Available RESUMO Conhecer a satisfação dos consumidores em relação aos serviços de saneamento configura-se como ferramenta capaz de auxiliar a gestão desses serviços. Este trabalho avaliou a satisfação dos consumidores a respeito dos serviços de saneamento básico gerenciados diretamente pelas prefeituras em 21 municípios do estado de Goiás. Para a avaliação da satisfação, no que diz respeito às características de todos os componentes do saneamento, foi utilizada a escala intervalar. Procedeu-se à verificação da percepção dos consumidores em relação à realidade das condições de saneamento comparando os resultados obtidos por meio de formulários com as condições constatadas nas visitas aos órgãos municipais responsáveis pelo saneamento básico. Para tanto, foram aplicados 479 formulários a pessoas escolhidas aleatoriamente, e o número de formulários aplicados em cada município foi obtido utilizando a regra de alocação de Neyman. Verificou-se que a satisfação prevalece para abastecimento de água, coleta e transporte de resíduos. Porém, para drenagem urbana, disposição final dos resíduos e todos os indicadores referentes ao esgotamento sanitário, prevalece a insatisfação. Pequena parcela da população manifestou-se como indiferente, mostrando a preferência dos consumidores em se posicionar. Observou-se que a percepção dos consumidores condiz com a realidade dos municípios, o que pôde ser verificado durante a realização das visitas.

OS VIDEOJOGOS: AS REPRESENTAÇÕES DOS PAIS SOBRE A PRÁTICA DOS FILHOS

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Sílvia Coimbra

2015-04-01

Full Text Available Os videojogos são um fenómeno com crescimento progressivo desde a década de 70, alojando-se na vida das crianças, dos jovens e até mesmo na dos adultos. Ao passarem muitas horas em frente a um ecrã as crianças podem estar a tornar-se pequenas pessoas inativas, porque as horas que passam a jogar videojogos poderiam ser dedicadas à actividade física, tornando assim as crianças mais ativas e menos sedentárias (Bergamasco et al., 2008. O magnetismo exercido pelos videojogos pode assustar os intervenientes da educação, pois as crianças e jovens de hoje passam horas a jogar, e nesse período de tempo não se consegue saber o que é que as crianças aprendem, ou não aprendem (Pereira, 2007. As investigações nesta área têm abordado esta temática, demonstrando que é importante ter atenção aos conteúdos e número de horas que as crianças dispensam a jogar de forma a poder haver um maior controle desse tempo (Marivoet, 2001; Moita, 2007; Pereira, 2007.Objetivo: Contribuir para o conhecimento e aprofundamento da problemática dos videojogos, relativamente à representação que os pais têm sobre a sua influência no desenvolvimento das crianças, as horas que os seus filhos passam a jogar e ainda se o tempo de jogo furta tempo à actividade física.

Aspectos históricos dos estudos caso-controle

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Rêgo Marco Antônio Vasconcelos

2001-01-01

Full Text Available Este texto apresenta um relato da evolução dos estudos de caso-controle (ECC até o final dos anos 80. A comparação de dois grupos quanto à exposição a um fator de risco é verificada desde o século XVII. A segunda metade do século XIX significou o declínio da Epidemiologia das "populações", e os primeiros ECC só foram realizados na década de 20. O avanço do método ocorreu na segunda metade do século, com destaque para as investigações sobre câncer de pulmão e hábito de fumar. As principais contribuições dos estudiosos do método foram o uso da odds ratio como estimativa do risco relativo; a definição dos aspectos estatísticos da análise de dados de estudos retrospectivos; o cálculo do risco atribuível e da fração etiológica para ECC; e a discussão da essência dos ECC. Os críticos referiam as fragilidades do método e a susceptibilidade aos bias. Conclui-se que os ECC tiveram aplicação crescente nas últimas décadas, sendo utilizados em diversas áreas da epidemiologia, constituindo-se em um importante instrumento para as ações de Saúde Pública.

Competências em informação dos estudantes de graduação para elaboração dos trabalhos acadêmicos

OpenAIRE

Silva, Lúcia Vera da

2009-01-01

A competência em informação dos estudantes de graduação, durante a elaboração do trabalho acadêmico, bem como o papel representado pela biblioteca universitária, nesse processo, constituíram o tema deste trabalho. O objetivo foi o de identificar as dificuldades dos estudantes de graduação no processo de elaboração do Trabalho de Conclusão de Curso, decorrentes do desconhecimento do papel e da lógica de funcionamento da biblioteca, como também dos seus produtos e serviços. Procurou-se analisar...

POLÍTICAS PÚBLICAS E DIREITOS DOS IDOSOS

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Amanda Santa Cruz Melo

2017-04-01

Full Text Available O presente trabalho busca identificar as políticas públicas criadas pelo Poder Público, bem como pela sociedade civil, para assegurar a proteção, promoção e inclusão social dos idosos, no Brasil. Pretende-se resgatar o papel do idoso no seio familiar e comunitário, valorizando o conhecimento adquirido ao longo da existência e respeitando os limites impostos com a chegada da velhice. Contudo, em virtude da inobservância dos direitos humanos, dos preceitos constitucionais e da legislação infraconstitucional, muitas ações conjuntas devem ser realizadas para que este segmento social tenha os seus direitos resguardados, uma vez que o processo de envelhecimento é crescente em todo o mundo e atinge a todos, indistintamente.

Defesa dos direitos humanos: sistemas regionais

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Hélio Bicudo

2003-04-01

Full Text Available O texto discorre sobre a institucionalização dos sistemas de promoção dos Direitos Humanos, ao longo do século XX. Tomando a Declaração Universal dos Direitos do Homem, de 1948, como base e ponto de partida, o articulista aborda as três principais vertentes dos sistemas de promoção desses direitos: a européia, a americana e a africana. A evolução de cada uma delas descrita analógica e epistemologicamente, de forma a salientar singularidades sem perder de vista as influências recíprocas ou mesmo as determinantes próprias do contexto espaço-social. Para finalizar, o articulista destaca a importância do Tribunal Penal Internacional no estabelecimento de uma justiça ecumênica. Concomitantemente, alerta para o perigo contido na ameaça de os EUA não o ratificarem.The text underlines the institutional character acquired by the main systems to promote Human Rights in the twentieth century. Taking the Universal Human Rigths Declaration, of 1948, as the basis for analysis, the author brings up three different approaches to promote these rights: the European, the American and the African. The evolution of each of them is described using its procedure as a basic reference. Besides, an analogical analysis, brings to the fore singularities, without ignoring reciprocal influences dictated by particular contexts, though. The author stresses the importance of the International Penal Court, as a means to establish ecumenical justice. At the same time, he reminds the reader of the risks implicit in the possible non-ratification of the IPC by United States.

Uso do radar penetrante no solo (GPR na investigação dos solos dos tabuleiros costeiros no litoral norte do estado da Bahia

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J. M. Ucha

2002-06-01

Full Text Available Foram estudados nove perfis ao longo de uma toposseqüência sobre os sedimentos do Grupo Barreiras, na Fazenda Rio Negro, município de Entre Rios (BA, utilizando a prospecção eletromagnética por meio do Radar Penetrante no Solo - "Ground-penetrating radar - GPR", objetivando analisar a utilização dessa ferramenta na aquisição de informações sobre as feições que ocorrem no solo, mediante a comparação entre os radargramas obtidos e a descrição pedológica. O equipamento utilizado foi um Geophysical Survey System modelo GPR SR system-2, com antena de 80 MHz. A análise radargramétrica confirmou o aparecimento dos fragipãs e duripãs em profundidade, que ocorrem sempre acompanhados de um processo de transformação dos solos do tipo Latossolo Amarelo e Argissolo Amarelo em Espodossolo. Os padrões de reflexão mostram claramente os domínios dos solos argilosos e dos solos arenosos, com e sem a presença dos horizontes endurecidos.

O ENTENDIMENTO DOS ESTUDANTES DOS CURSOS TÉCNICOS DE ADMINISTRAÇÃO SOBRE AS ATIVIDADES REALIZADAS PELO MARKETING

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Laeber, Izabel Maria; Mainardes, Emerson Wagner; Monte-mor, Danilo Soares

2016-01-01

Este estudo teve como objetivo avaliar a percepção dos estudantes dos cursos técnicos em Administração sobre o seu entendimento das atividades realizadas por um profissional de Marketing. O referencial teórico abrange conceitos sobre marketing, mix de marketing formado pelos 4 Ps (produto, preço, praça e promoção) e o ensino de marketing. No que se refere aos aspectos metodológicos, realizou-se um estudo de caráter descritivo e de natureza quantitativa, tendo como instrumento de coleta de dad...

LEVANTAMENTO DOS DADOS DEMOGRÁFICOS DO MUNICÍPIO DE CAMPOS DOS GOYTACAZES/RJ COMO SUBSÍDIOS PARA A PEDAGOGIA DO ENVELHECIMENTO

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Paula Rodrigues Mothé

2016-12-01

Full Text Available Este estudo disponibiliza um levantamento dos dados demográficos do município de Campos dos Goytacazes/RJ, fator imprescindível para o desenvolvimento de estratégias para a pedagogia do envelhecimento. Atualmente, segundo dados do Censo do IBGE (2010,  existem 463.731 pessoas, sendo que o índice de envelhecimento corresponde a 12% da população total. Este segmento etário está aumentando e configura um desenho demográfico que refletirá nos próximos anos em uma maior população idosa. A investigação partiu de uma pesquisa bibliográfica sobre a questão principal que é o envelhecimento populacional. A pesquisa caracteriza-se como de natureza quantitativa. Levando em consideração o objetivo proposto, tem caráter descritivo e exploratório, na qual foram utilizados dados obtidos dos Censos Demográficos e dos Indicadores Sociais do IBGE, do período de 1991 a 2015. Como resultado, pode-se perceber que o crescimento e o envelhecimento demográfico da população indicam  um fenômeno relevante que vem modificando a perspectiva de vida dos indivíduos. O grande desafio que se coloca para a sociedade contemporânea envolve o reconhecimento do ser enquanto sujeito de direitos, dos princípios de independência, participação, dignidade, assistência e autorrealização estabelecidos pela ONU. Nesse sentido, constata-se, principalmente, a relevância da educação, para além de um direito social, mas como possibilidade de mudança de visão em relação ao envelhecimento. Uma pedagogia do envelhecer que envolva uma dinâmica de co-educação(parcerias que proporcione ao idoso a inserção social, o reconhecimento das condições de sobrevivência e garantias de melhor qualidade de vida, dignidade e cidadania.

O RETORNO DOS JOVENS À ESCOLA: A CENTRALIDADE DO TRABALHO

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Cláudia Borges Costa

2016-06-01

Full Text Available O artigo discute a EJA considerando a centralidade do trabalho no retorno dos jovens à escola. Investigou-se o perfil dos educandos do Proeja-Fic/Pronatec da rede municipal de Goiânia/GO considerando cento e oito questionários formulados pela Divisão de Ensino Fundamental de Adolescentes, Jovens e Adultos aos educandos de uma escola que experimenta a integração entre formação geral e qualificação profissional no ensino fundamental; e 14 (catorze entrevistas com educandos que declararam exercer alguma atividade profissional no momento. A pesquisa foi impulsionada pela reflexão sobre a situação dos jovens trabalhadores, apontando o trabalho enquanto motivação nesse retorno dos jovens à escola.

As políticas sociais nos fundamentos dos projetos pedagógicos dos cursos de Psicologia

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Pablo Sousa Seixas

Full Text Available Resumo A Psicologia aproximou-se das políticas sociais, evocando mudanças para a atuação e formação nesse campo. O objetivo deste artigo é investigar o lugar que as políticas sociais ocupam nos fundamentos teórico-político dos Projetos Pedagógicos dos Cursos (PPCs de graduação em Psicologia no Brasil. Foram analisados 40 PPCs de instituições públicas e privadas das cinco regiões do Brasil. Analisaram-se os trechos sobre políticas sociais localizados nos textos do PPC relativos a: a os fundamentos do curso e b a descrição das práticas profissionais (composta pelas ênfases curriculares e locais de atuação indicados. Como resultados, identificou-se que ao tratarem das políticas sociais, os cursos possuem um foco técnico e prático, preocupando-se, recorrentemente, com a promoção de saúde e compromisso social - configuração identificada nas duas dimensões analisadas. Merece atenção a definição limitada dos dois últimos conceitos, corroborando com a indicação da literatura sobre as restrições do seu uso para direcionar as políticas sociais.

Da arquitetura dos textos a eloquência dos lugares

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Rochelle de Quadros Loguércio; UFPEL

2008-01-01

Uma das questões importantes nas perspectivas pós- moderna e pós-estruturalistas em educação é a possibilidade de ler textos que estão visibilizados de outras formas que não as da fala e da escrita. Outro e evidenciar uma discussão sobre a linguagem caracterísitca de um fazer científico e de um fazer educacional tendo como  plano de fundo as falas da Educação em Bioquímica. Pretende-se mostrar que as linguagens dos campos de origem -bioquímica e educação - conformam e determinam um modo de li...

A privacidade dos pacientes e as ações dos enfermeiros no contexto da internação hospitalar

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Narciso Vieira Soares

2010-01-01

A privacidade é um direito individual que contempla situações relacionadas à proteção da intimidade dos sujeitos, respeito à dignidade, limitação de acesso ao corpo, aos objetos íntimos, aos relacionamentos familiares e sociais e a enfermagem tem como desafio a reflexão ética sobre a responsabilidade e compromisso de suas ações, nesse âmbito. O objetivo geral da pesquisa consistiu em analisar situações relativas à privacidade do paciente no cotidiano da enfermagem hospitalar e as ações dos en...

Dinâmica dos micronutrientes em cafeeiros enxertados

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André Dominghetti Ferreira

2013-04-01

Full Text Available As respostas à disponibilidade dos nutrientes variam entre espécies distintas dentro de um mesmo gênero, por causa, principalmente, das exigências nutricionais variáveis, capacidade de absorção, translocação e utilização dos nutrientes. O objetivo deste trabalho foi avaliar a eficiência de absorção, translocação e uso dos micronutrientes por diferentes cultivares de Coffea arabica L., enxertados em Apoatã IAC 2258 (Coffea canephora. O experimento foi instalado em casa de vegetação, utilizando-se o método de cultivo em solução nutritiva. Foi utilizado um fatorial 7 x 3 + 2, sendo sete cultivares de Coffea arabica L. (Palma II, Catucaí 2 SL, Oeiras MG 6851, Obatã IAC 1669-20, Acauã, Topázio MG 1190 e Paraíso MG H 419-1, três tipos de mudas (pé franco, autoenxertada e enxertada sobre o cultivar Apoatã IAC 2258 e duas testemunhas (Apoatã autoenxertado e Apoatã pé franco. O porta-enxerto utilizado influenciou negativamente na absorção de boro, ferro e manganês. A translocação dos micronutrientes boro e cobre obteve maiores índices nas mudas enxertadas. O cultivar Palma II, quando enxertado, apresentou o maior índice de utilização dos nutrientes, mostrando-se passível de ser enxertado. O porta-enxerto utilizado mostrou-se apto para a enxertia, por não sofrer influência negativa, tanto pela enxertia, quanto pelos cultivares utilizados.

Compromissos dos Contratos Psicológicos e Uso Diagnóstico dos Sistemas de Controle Gerencial

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Ivan Canan

2016-01-01

Full Text Available Ao investigar os compromissos assumidos pelos Agentes de Fiscalização da Agência Nacional de Telecomunicações (Anatel em seus contratos psicológicos e o uso diagnóstico do sistema de controle gerencial dessa entidade, este trabalho testou a hipótese de que os indivíduos tendem a se compromissarem mais com os assuntos aos quais são cobrados dentro das organizações. Trata-se de um trabalho teórico-empírico que assumiu que os compromissos compõem a parte da crença que os indivíduos desenvolvem sobre as relações recíprocas de trocas entre si e seus contratantes, conforme o modelo de Rousseau (1989; 1995. Também assumiu que a medida com que assuntos são cobrados dos membros de uma organização corresponde à sua percepção ao uso diagnóstico dos sistemas de controle formais e informais. Metodologicamente, a pesquisa se desenvolveu em duas fases, sendo a primeira qualitativa, com análise documental e análise de conteúdo dos documentos da organização; e a segunda, quantitativa, com a aplicação de questionários respondidos pelos indivíduos que ocupam a posição individual referenciada na organização, os quais avaliaram parâmetros comportamentais que agem sobre si e que foram identificados na primeira fase. Os dados obtidos apontaram que os 42 respondentes tendem a manter altos níveis de compromisso para com as regras e normas que são propostas para seu cargo. Os resultados estatísticos também sugerem que existe uma correlação positiva significante entre os compromissos assumidos e a percepção do uso diagnóstico dos sistemas de controle para os agentes de fiscalização que responderam ao questionário.

A segunda alma do partido dos trabalhadores

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André Singer

2010-12-01

Full Text Available Os dois mandatos de Lula formaram a síntese contraditória das "duas almas" que hoje habitam o PT. Foi o fato de ter implementado, simultaneamente, políticas que beneficiam o capital e promovem a inclusão dos mais pobres, com uma melhora relativa na situação dos trabalhadores, que permitiu a convivência dos princípios estabelecidos em sua fundação, no colégio Sion em 1980, e as diretrizes do programa de governo apresentadas em 2002 na convenção do Anhembi, em São Paulo.Lula's presidency seem to have blended PT's two apparently contradictory "souls". By implementing policies that favor capital while at the same time foster the social inclusion of the poor, and that have also improved working class citizens' life standards, Lula has been able, as a president, to preserve the ideals that animated the party's foundation and the more pragmatic programme for government set out in 2002.

A direita que saiu do armário: a cosmovisão dos formadores de opinião dos manifestantes de direita brasileiros

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Débora Messenberg

Full Text Available Resumo O artigo procura desvelar a cosmovisão (weltanschauung dos principais formadores de opinião dos manifestantes de direita brasileiros, que foram às ruas ao longo do ano de 2015. O trabalho pautou-se em pesquisa multimétodos, construída a partir do levantamento das postagens emitidas por esses atores sociais em suas páginas no Facebook, durante o ano em foco, além de matérias de suas autorias publicadas em blogs, jornais e revistas, como também vídeos de suas entrevistas e hangouts. Organizaram-se, ainda, dois grupos focais compostos por francos apoiadores e participantes dos referidos protestos, no intuito de compreender de que maneira a cosmovisão desses formadores de opinião foi efetivamente compartilhada pelos manifestantes de direita em 2015. Na análise dos dados coletados, optou-se pela sistematização de determinados campos semânticos, constituídos por certas ideias-força que se apresentam de forma regular e repetitiva no discurso desses agentes sociais. Funcionam, assim, como “chaves de leitura” para as interpretações da conjuntura política nacional e orientadores de suas ações. São eles: o antipetismo, o conservadorismo moral e os princípios neoliberais.

A influência dos vínculos organizacionais na consolidação dos Centros de Atenção Psicossociais

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Haiana Maria de Carvalho Alves

2013-10-01

Full Text Available O presente trabalho teve como objetivo investigar a influência dos vínculos organizacionais na consolidação dos Centros de Atenção Psicossocial (CAPS II e AD da cidade de Petrolina (PE. Entrevistas semiestruturadas foram realizadas com 18 membros da equipe multiprofissional de ambos os CAPS, sendo a amostra constituída por um representante de cada categoria profissional. A apreciação crítica dos dados baseou-se em análise de conteúdo elaborada a partir de categorizações dos discursos. Os resultados evidenciaram que, de modo geral, as equipes não possuem um conhecimento teórico suficiente sobre o sistema no qual estão inseridas. Além disso, embora haja um alto índice de satisfação, as precárias condições de trabalho, como a falta de reconhecimento profissional e insumos de trabalho, acabam afetando esta dinâmica institucional. Por fim, foi verificada também uma equivalência quantitativa referente aos aspectos afetivo e calculativo do comprometimento organizacional e uma estreita relação entre tempo de serviço e envolvimento com o trabalho.

O valor dos valores: avaliação de uma marca global por meio dos diversos brasis culturais

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Edar da Silva Añaña

2009-06-01

Full Text Available Este trabalho explora as influências dos valores pessoais e de outros elementos da cultura brasileira, na avaliação de uma marca de alcance mundial, por meio de quatro subculturas regionais que são utilizadas como unidades de análise. Utiliza as escalas de Rokeach (1968, 1973 para medir os valores humanos e a de Aaker (1997 para avaliar os atributos da marca, numa amostra de 308 pessoas, entre estudantes e profissionais de nível superior. O resultado confirma a existência de relações significativas entre os valores pessoais e a percepção da marca Nike, bem como a influência dos rituais, dos símbolos e de algumas variáveis demográficas, na forma como aquela marca é percebida e avaliada pelos consumidores. Confirma também a existência de diferenças significativas entre os elementos culturais das diversas subculturas, que podem ser bastante úteis na formulação de estratégias de marketing voltadas às diversas regiões do país.