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Sample records for adjustable speed drive

  1. Adjustable Speed Drives and Power Quality

    DEFF Research Database (Denmark)

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    This paper provides an overview and proposes cost-effective and efficient opportunities in improving power quality in Adjustable Speed Drive (ASD) systems. In particular, an Electronic Inductor (EI) technique has been used in single drives to overcome the existing challenges in conventional...

  2. Adjustable Speed Drives - Future Challenges and Applications

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Thoegersen, Paul

    2004-01-01

    The main trends within Adjustable Drives in industrial and appliance applications for the next decade are discussed based on the newest developments seen on the market and a few historical trends. Different drive configurations are presented and the general demands to adjustable speed drives...... are specified. Further on power architectures and motor types are discussed in a short term and long-term view. Possible drivers of the future development are identified, and the concept of an ?Electronic Motor? is discussed. A number of applications are presented where variable speed is attractive....

  3. Output filters for AC adjustable speed drives

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Hanigovszki, Norbert; Landkildehus, Jorn, Jorn

    2007-01-01

    -phase applications the occurrence of common-mode (CM) voltage is inherent due to asymmetrical output pulses [1]. Consequently, several secondary effects arise at the inverter's output: high-frequency conducted and radiated emissions, leakage current, motor insulation stress due to wave reflection [2], bearing stress......The standard industrial solution for adjustable speed drives (ASD) is the use of induction motors (IM) fed by voltage-source inverters (VSI). The inverter generates a pulsewidth modulated (PWM) voltage, with dv/dt values of about 6 kV/¿s or even more. In three-leg inverters for three...

  4. Interharmonic analysis and mitigation in adjustable speed drives

    DEFF Research Database (Denmark)

    Soltani, Hamid; Loh, Poh Chiang; Blaabjerg, Frede;

    2014-01-01

    This paper presents the theoretical background and studies on the supply side current interharmonics in a double-stage Adjustable Speed Drive (ASD), when they are initiated by motor current imbalance. Some useful approaches are then proposed to compensate for these interharmonic currents in parti...

  5. Adjustable speed drives: Applications and R&D needs

    Energy Technology Data Exchange (ETDEWEB)

    Stefanovic, V.R.

    1995-09-01

    The largest opportunity for the growth of adjustable speed drives (ASDs) during the next 5-6 years is in pump, fan and compressor (PFC) applications where a constant, fixed speed operation is converted to adjustable speed in order to realize energy savings. Inverter supplied induction motors are and will continue to be predominately used in these applications. Over the long term (10-15 years), the greatest ASD growth is expected in large volume consumer applications: first in hybrid electric vehicles (EVs) and in residential heating, ventilation and air-conditioning (HVAC). Both induction and a variety of AC Permanent Magnet motors are expected to be the dominant technology in this new field. The traditional ASD applications in industries which require adjustable speed (such as machine tools, robotics, steel rolling, extruders, paper mill finishing lines, etc.) offer a relatively limited potential for above average ASD growth since most of these applications have already converted to electronic speed control. As a result, ASD growth in this sector will essentially track the growth of the corresponding industries. If realized, both short and long term ASD growth opportunities will result in significant advancements of ASD technology, which will then substantially affect all other, more fragmented, ASD applications. In fact, any single large volume ASD application will serve as a catalyst for improving ASD characteristics in all other ASD applications with the same voltage rating. ASD cost and reliability (defined in the context of application compatibility) are the two most important factors which will determine whether the ASD growth opportunities are realized. Conversely, any technological improvement which carries a cost increase will be restricted to niche applications, at best. Consequently, future R & D efforts should be directed to secure reduction in ASD cost and improvement in ASD reliability. A specific action plan is outlined in this report.

  6. Characterization of Input Current Interharmonics in Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Soltani, Hamid; Davari, Pooya; Zare, Firuz

    2017-01-01

    -edge symmetrical regularly sampled Space Vector Modulation (SVM) technique, on the input current interharmonic components are presented and discussed. Particular attention is also given to the influence of the asymmetrical regularly sampled modulation technique on the drive input current interharmonics...

  7. Speed/position sensor fault tolerant control in adjustable speed drives - A review.

    Science.gov (United States)

    Bourogaoui, M; Sethom, H Ben Attia; Belkhodja, I Slama

    2016-09-01

    The position sensor is one of the most used devices in Adjustable Speed Drives (ASDs). Its use is mandatory in electric machines vector control. In this paper, an interest was addressed to this field. Indeed, a bibliographical review, about Fault Detection and Isolation (FDI) and Fault Tolerant Control (FTC) in ASDs, is presented. Thus, the paper deals with position sensor FDI and sensorless control-based FTC in ASDs. Moreover, this issue is mainly addressed to position sensor faults in ASDs. This paper is based on a wide literature review referring to scientific papers and manufacturer׳s technical documents. In total, 186 references in the open literature, dating back to 1981, have been investigated in order to perform this study.

  8. FLC based adjustable speed drives for power quality enhancement

    Directory of Open Access Journals (Sweden)

    Sukumar Darly

    2010-01-01

    Full Text Available This study describes a new approach based on fuzzy algorithm to suppress the current harmonic contents in the output of an inverter. Inverter system using fuzzy controllers provide ride-through capability during voltage sags, reduces harmonics, improves power factor and high reliability, less electromagnetic interference noise, low common mode noise and extends output voltage range. A feasible test is implemented by building a model of three-phase impedance source inverter, which is designed and controlled on the basis of proposed considerations. It is verified from the practical point of view that these new approaches are more effective and acceptable to minimize the harmonic distortion and improves the quality of power. Due to the complex algorithm, their realization often calls for a compromise between cost and performance. The proposed optimizing strategies may be applied in variable-frequency dc-ac inverters, UPSs, and ac drives.

  9. Variable speed rotary compressor and adjustable speed drive efficiencies measured in the laboratory

    Science.gov (United States)

    Miller, W. A.

    Two state-of-the-art variable-speed rotary compressors, of nominal one ton cooling capacity, were instrumented and tested in the laboratory. Both compressors were identical except for their respective variable-speed drive systems (i.e., motor and inverter). One compressor had an inverter driven induction motor (IDIM) drive, and the other had a permanent magnet electronically commutated motor drive (PM-ECM). The laboratory study evaluated the compressor's efficiency under representative variable-speed conditions. Testing was conducted as a function of compressor drive frequency and of refrigerant condensing and evaporating conditions. Saturated refrigerant conditions, inlet superheat, and subcooling were controlled using a secondary refrigerant calorimeter. Spectrum analysis was conducted on the current input to one phase of the three-phase drive systems to measure motor speed and characterize harmonic content of the inverters. An optimal volt per Hz ratio was determined at 120-, 90-, 60-, and 30-Hz drive frequencies and at different load conditions for the rotary with induction motor as driven by a PWM inverter and also by a motor generator set (ideal induction motor drive). Variation of voltage input to the compressor had the largest effect at the lowest drive frequency (30Hz). A 5 percent variation about the optimal voltage at 30 Hz frequency caused a roughly 5 percent drop in compressor isentropic efficiency. Calorimeter data were used to develop modulating compressor and drive system performance maps. Performances of the two compressors were compared and the rotary with PM-ECM drive showed better efficiency trends at 30-Hz drive frequency. Above the 30-Hz drive frequency no clear advantage was observed for the PM-ECM vs the IDIM, possibly due to oversizing of the PM-ECM inverter.

  10. Input current interharmonics in adjustable speed drives caused by fixed-frequency modulation techniques

    DEFF Research Database (Denmark)

    Soltani, Hamid; Davari, Pooya; Loh, Poh Chiang;

    2016-01-01

    Adjustable Speed Drives (ASDs) based on double-stage conversion systems may inject interharmonics distortion into the grid, other than the well-known characteristic harmonic components. The problems created by interharmonics make it necessary to find their precise sources, and, to adopt an approp...

  11. Performance Evaluation of Electronic Inductor-Based Adjustable Speed Drives with Respect to Line Current Interharmonics

    DEFF Research Database (Denmark)

    Soltani, Hamid; Davari, Pooya; Zare, Firuz;

    2017-01-01

    Electronic Inductor (EI)-based front-end rectifiers have a large potential to become the prominent next generation of Active Front End (AFE) topology used in many applications including Adjustable Speed Drives (ASDs) for systems having unidirectional power flow. The EI-based ASD is mostly attract...

  12. Adjustable Speed Drives in the Next Decade. Future Steps in Industry and Academia

    DEFF Research Database (Denmark)

    Thøgersen, Paul; Blaabjerg, Frede

    2004-01-01

    The main trends for the next decade within the multi-disciplinarian field of adjustable speed drives are discussed, and a number of topics are especially addressed in this paper. The topics include market development over the last decade, historical development in power converter volume and weigh...

  13. Design and Implementation of an Adjustable Speed Drive for Motion Control Applications

    OpenAIRE

    J. Rodríguez-Reséndiz; J. M. Gutiérrez-Villalobos; D. Duarte-Correa; J. D. Mendiola-Santibañez; I. M. Santillán-Méndez

    2012-01-01

    In this article a hardware topology meant to compare the velocity performance of both an induction motor and a permanent magnet (PM) AC three-phase motor is presented. A variable reference is tracked by the sensorless vectorcontrolled adjustable speed drive (ASD) that permits, by means of the same type of control, performing the speed control loop of the two motors. The algorithms are programmed on a digital signal processor (DSP) in order to ensure efficient use of energy in the transistor ...

  14. Effects of passive components on the input current interharmonics of adjustable-speed drives

    DEFF Research Database (Denmark)

    Soltani, Hamid; Blaabjerg, Frede; Zare, Firuz;

    2016-01-01

    speed drives with and/or without motor current imbalance. The investigation is done at different motor operating frequencies and load torque values. It shows that selecting the small filter components (ac choke, dc choke and dc-link capacitor) results in different performances in respect to those......Current and voltage source Adjustable Speed Drives (ASDs) exert distortion current into the grid, which may produce some interharmonic components other than the characteristic harmonic components. This paper studies the effects of passive components on the input current interharmonics of adjustable...... interharmincs issued by motor current imbalance and other non-characteristic interharmonics. The results are helpful for engineers investigating the effects of drive filters on the input current interharmonic components....

  15. Fifteen Years of Operation at NASA's National Transonic Facility with the World's Largest Adjustable Speed Drive

    Science.gov (United States)

    Sydnor, George H.; Bhatia, Ram; Krattiger, Hansueli; Mylius, Justus; Schafer, D.

    2012-01-01

    In September 1995, a project was initiated to replace the existing drive line at NASA's most unique transonic wind tunnel, the National Transonic Facility (NTF), with a single 101 MW synchronous motor driven by a Load Commutated Inverter (LCI). This Adjustable Speed Drive (ASD) system also included a custom four-winding transformer, harmonic filter, exciter, switch gear, control system, and feeder cable. The complete system requirements and design details have previously been presented and published [1], as well as the commissioning and acceptance test results [2]. The NTF was returned to service in December 1997 with the new drive system powering the fan. Today, this installation still represents the world s largest horizontal single motor/drive combination. This paper describes some significant events that occurred with the drive system during the first 15 years of service. These noteworthy issues are analyzed and root causes presented. Improvements that have substantially increased the long term viability of the system are given.

  16. Commutation effect of Adjustable Speed Drives due to installation of active harmonic filters

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Kalaschnikow, Sergej; Hansen, Steffan;

    2011-01-01

    The success of designing an industrial installation with Active Filters depends on how precise the load profile of the application is known, because this determines the amount of harmonic currents to be compensated. However, once the Active Filter is added to the installation, the harmonic curren...... and sizing industrial Active Filter applications together with Adjustable Speed Drives. Examples of using the developed toolbox are given in the paper, supported with practical measurements....... the commutation behavior of Adjustable Speed Drives when their harmonic currents are compensated by a Shunt Active Filter. The method is formulated as an analytical computation algorithm verified by simulations. Further on the method is implemented in a Harmonic Calculation Toolbox which facilitates calculation...

  17. PV Array Driven Adjustable Speed Drive for a Lunar Base Heat Pump

    Science.gov (United States)

    Domijan, Alexander, Jr.; Buchh, Tariq Aslam

    1995-01-01

    A study of various aspects of Adjustable Speed Drives (ASD) is presented. A summary of the relative merits of different ASD systems presently in vogue is discussed. The advantages of using microcomputer based ASDs is now widely understood and accepted. Of the three most popular drive systems, namely the Induction Motor Drive, Switched Reluctance Motor Drive and Brushless DC Motor Drive, any one may be chosen. The choice would depend on the nature of the application and its requirements. The suitability of the above mentioned drive systems for a photovoltaic array driven ASD for an aerospace application are discussed. The discussion is based on the experience of the authors, various researchers and industry. In chapter 2 a PV array power supply scheme has been proposed, this scheme will have an enhanced reliability in addition to the other known advantages of the case where a stand alone PV array is feeding the heat pump. In chapter 3 the results of computer simulation of PV array driven induction motor drive system have been included. A discussion on these preliminary simulation results have also been included in this chapter. Chapter 4 includes a brief discussion on various control techniques for three phase induction motors. A discussion on different power devices and their various performance characteristics is given in Chapter 5.

  18. Design and Implementation of an Adjustable Speed Drive for Motion Control Applications

    Directory of Open Access Journals (Sweden)

    J. Rodríguez-Reséndiz

    2012-04-01

    Full Text Available In this article a hardware topology meant to compare the velocity performance of both an induction motor and a permanent magnet (PM AC three-phase motor is presented. A variable reference is tracked by the sensorless vectorcontrolled adjustable speed drive (ASD that permits, by means of the same type of control, performing the speed control loop of the two motors. The algorithms are programmed on a digital signal processor (DSP in order to ensure efficient use of energy in the transistor bridge and proper tracking of the reference at low and high speeds. Regarding the torque performance, a laboratory test bed based on a torquemeter and two motors is constructed. The hardware implementation includes the power and the digital stages. A serial communication between the PC and the ASD is accomplished to put into operation in the user front-end because a high speed sample frequency is required for the analysis software that runs in the PC. This interface is used not only as comparing the speed response of the motors signals but also as looking the power quality analysis of each motor measurements based on software. Results are presented to demonstrate the effectiveness of the sensorless scheme.

  19. LC Filter Design for Wide Band Gap Device Based Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Vadstrup, Casper; Wang, Xiongfei; Blaabjerg, Frede

    2014-01-01

    the LC filter with a higher cut off frequency and without damping resistors. The selection of inductance and capacitance is chosen based on capacitor voltage ripple and current ripple. The filter adds a base load to the inverter, which increases the inverter losses. It is shown how the modulation index......This paper presents a simple design procedure for LC filters used in wide band gap device based adjustable speed drives. Wide band gap devices offer fast turn-on and turn-off times, thus producing high dV/dt into the motor terminals. The high dV/dt can be harmful for the motor windings and bearings...... affects the capacitor capacitor and the inverter current....

  20. LC-filter Resonance Cancellation with DPWM Inverters in Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Vadstrup, Casper; Wang, Xiongfei; Blaabjerg, Frede

    2015-01-01

    Discontinuous PWM methods cannot easily be used in LC-filtered inverters for adjustable speed drives, as it causes resonances in the filter. This paper present a new method to cancel the resonance and compares this method to previously proposed methods. Wide band gap devices are entering the market...... offering high switching frequencies and low switching loss due to fast turn on and turn off. The fast turn on and turn off generates high dV/dt, which must be filtered e.g. to protect motors from bearing stress and avoid EMC issues. Discontinuous PWM methods can be reduced to reduce the losses......, no resonance will be generated in the filter. Simulations show that the proposed method effectively reduces the resonance in the filter....

  1. The Use of Active Elements to Reduce the Size and Weight of Passive Components in Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan

    Adjustable speed drives are considered as workhorse of industry due to various applications in different kind of industries. According to a market survey, low voltage drives are most profitable in the drive industries. The drive consists of a machine and a converter, which processes grid power...... allows modeling the neutral-point voltage dynamics as a continuous function of the power drawn from the converter. This model shows that the neutral-point current is proportional to the power drawn from the converter, and it enables the use of well established classical control theory for the neutral...

  2. Analysis of cutting-edge techniques in the high voltage and high power adjustable speed drive systems

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The high voltage and high power adjustable speed drive (ASD) system is one of the most attractive fields in power electronics, and it is also a very crucial technique for energy saving and emission reduction. This paper discussed and analyzed the main cutting-edge knowledge and issues in the process of exploiting the high voltage and high power ASD system.

  3. Using transfer ratio to evaluate EMC design of adjustable speed drive systems

    NARCIS (Netherlands)

    Zhao, D.; Ferreira, B.; Polinder, H.; Roc'h, A.; Leferink, F.B.J.

    2006-01-01

    This paper proposes a way to evaluate the conducted electromagnetic compatibility performance of variable speed drive systems. It is considered that the measured noise level is determined by two factors, the level of the noise source and the conversion efficiency of the propagation path from the sou

  4. Mitigation of Harmonics and Interharmonics in VSI-Fed Adjustable Speed Drives

    Directory of Open Access Journals (Sweden)

    D.Uma

    2013-04-01

    Full Text Available The components of harmonics are integral multiple of the fundamental component and the components of inter-harmonics are are non integral multiple of the fundamental component. AC-DC-AC conversion systems used in variable speed drive are sources of inter-harmonics. There are several reasons for inter-harmonic generation in variable speed drives. In this paper, the generation of inter-harmonics in the supply side due to indirect frequency converter is considered. A passive filter is designed to mitigate harmonics and inter-harmonics. The accuracy of the proposed method is verified using the simulationtool of PSIM. Simulated results of VSI-fed induction motor with the proposed filter prove the effectiveness of mitigation.

  5. Analysis of cutting-edge techniques in the high voltage and high power adjustable speed drive systems

    Institute of Scientific and Technical Information of China (English)

    ZHAO ZhengMing; BAI Hua; YUAN LiQiang

    2009-01-01

    The high voltage and high power adjustable speed drive (ASD) system is one of the most attractive fields in power electronics, and it is also a very crucial technique for energy saving and emission re-duction. This paper discussed and analyzed the main cutting-edge knowledge and issues in the proc-ess of exploiting the high voltage and high power ASD system.

  6. Passive wide spectrum harmonic filter for adjustable speed drives in oil and gas industry

    Science.gov (United States)

    Al Jaafari, Khaled Ali

    Non-linear loads such as variable speed drives constitute the bulky load of oil and gas industry power systems. They are widely used in driving induction and permanent magnet motors for variable speed applications. That is because variable speed drives provide high static and dynamic performance. Moreover, they are known of their high energy efficiency and high motion quality, and high starting torque. However, these non-linear loads are main sources of current and voltage harmonics and lower the quality of electric power system. In fact, it is the six-pulse and twelve-pulse diode and thyristor rectifiers that spoil the AC power line with the dominant harmonics (5th, 7th, 11th). They provide DC voltage to the inverter of the variable speed drives. Typical problems that arise from these harmonics are Harmonic resonances', harmonic losses, interference with electronic equipment, and line voltage distortion at the Point of Common Coupling (PCC). Thus, it is necessary to find efficient, reliable, and economical harmonic filters. The passive filters have definite advantage over active filters in terms of components count, cost and reliability. Reliability and maintenance is a serious issue in drilling rigs which are located in offshore and onshore with extreme operating conditions. Passive filters are tuned to eliminate a certain frequency and therefore there is a need to equip the system with more than one passive filter to eliminate all unwanted frequencies. An alternative solution is Wide Spectrum Harmonic passive filter. The wide spectrum harmonic filters are becoming increasingly popular in these applications and found to overcome some of the limitations of conventional tuned passive filter. The most important feature of wide spectrum harmonic passive filters is that only one capacitor is required to filter a wide range of harmonics. Wide spectrum filter is essentially a low-pass filter for the harmonic at fundamental frequency. It can also be considered as a

  7. Enhanced Phase-Shifted Current Control for Harmonic Cancellation in Three-Phase Multiple Adjustable Speed Drive Systems

    DEFF Research Database (Denmark)

    Yang, Yongheng; Davari, Pooya; Zare, Firuz

    2017-01-01

    A phase-shifted current control can be employed to mitigate certain harmonics induced by the Diode Rectifiers (DR) and Silicon-Controlled Rectifiers (SCR) as the front-ends of multiple parallel Adjustable Speed Drive (ASD) systems. However, the effectiveness of the phase-shifted control relies on......-shifted current control is a cost-effective solution to multiple ASD systems in terms of harmonic cancellation.......A phase-shifted current control can be employed to mitigate certain harmonics induced by the Diode Rectifiers (DR) and Silicon-Controlled Rectifiers (SCR) as the front-ends of multiple parallel Adjustable Speed Drive (ASD) systems. However, the effectiveness of the phase-shifted control relies...... on the loading condition of each drive unit as well as the number of drives in parallel. In order to enhance the harmonic cancellation by means of the phase-shifted current control, the currents drawn by the rectifiers should be maintained almost at the same level. Thus, this paper firstly analyzes the impact...

  8. Power-Quality-Oriented Optimization in Multiple Three-Phase Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Yang, Yongheng; Davari, Pooya; Blaabjerg, Frede

    2016-01-01

    to minimize the THD level of the total current at the point of common coupling. Simulations with the optimized results are carried out and laboratory tests on a two-drive system are provided to demonstrate the phase-shifting harmonic mitigation scheme. Issues concerning the practical implementation......) the phaseshifts (i.e., firing angles) for the corresponding SCR-fed drives. This paper thus adopts a particle swarm optimization algorithm to optimize the power levels and the firing angles for multi-drive systems considering a fixed number of drives when practically implemented. The optimization is done...

  9. Interharmonic mitigation of adjustable speed drives using an active DC-link capacitor

    DEFF Research Database (Denmark)

    Soltani, Hamid; Loh, Poh Chiang; Blaabjerg, Frede;

    2015-01-01

    operating frequency. As there is a growing discussion about the interharmonic effects on the grid and its limitation, the reduction and mitigation of these components is worthwhile especially when more drives are tied to the grid. This paper proposes a new dc-link active capacitor in order to reduce...

  10. DUAL THREE-PHASE ADJUSTABLE SPEED DRIVE WITH SYNCHRONIZED SPACE-VECTOR MODULATION

    Directory of Open Access Journals (Sweden)

    Oleschuk V.I.

    2008-04-01

    Full Text Available Split-phase symmetrical motor drive on the base of two voltage source inverters, controlled by algorithms of synchronized pulse width modulation (PWM, has been investigated. Simulation results are presented for dual three-phase power conversion systems with continuous, discontinuous and combined versions of synchronized PWM.

  11. Possibilities of increased power output from existing generator plants. Feasible changes of existing generators. New technology, ASD (Adjustable Speed Drives); Muligheter for oekt effekt fra eksisterende generatoranlegg. Mulige endringer av bestaaende generatorer. Ny teknologi, ASD (Adustable Speed Drives)

    Energy Technology Data Exchange (ETDEWEB)

    Elstroem, A.

    1996-12-31

    The present paper relates to the increase of power output from existing generator plants in Norway by new operation profiles. The paper focuses on the consequences of increasing the power turnover and production with a particular attention to the generator itself. In addition, some of the possibilities on the use of an ASD (Adjustable Speed Drives) installation are elucidated, which is a concept on regulating the number of revolutions within small limits by synchronous rotation. According to the author, the power output of generator increases between 10 to 30%

  12. Reduce consumption, improve production. Electronic adjustable speed drives and high performance motors; Consommez moins, produisez mieux. Variateurs electroniques de vitesse et moteurs performants

    Energy Technology Data Exchange (ETDEWEB)

    David, A.; Pratmarty, D.; Dessoude, M. [Electricite de France (EDF), 92 - Clamart (France). Direction des Etudes et Recherches

    1995-10-01

    The electric power consumption from electric motors accounts for up to two third of industry`s electric power consumption. When equipped with electronic adjustable speed drives (ASD), energy savings of 10 to 50 percent, with an estimated average of 25 percent, may be achieved for pumps, fans and compressors, which account for 63 percent of motor applications. The advantages of electronic ASD, the installation recommendations which should be applied, the sensibility of ASDs to power cuts and harmonics, the characteristics of high efficiency motors, the energy aspects of motors with or without electronic ASD, and the EDF-ADEME (French energy conservation agency) approach for electricity demand side management, are described

  13. Police enforcement and driving speed.

    NARCIS (Netherlands)

    2008-01-01

    Speed limits are violated frequently in the Netherlands. As speed is an important factor in road crashes, the surveillance of driving speeds is one of the spearheads in the policy plans of the Dutch police. Different methods of speed enforcement have proved to be effective in reducing speed and cras

  14. A Review of Electronic Inductor Technique for Power Factor Correction in Three-Phase Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    Electronic Inductor (EI) techniques are promising approaches for improving the grid-side current quality, and they are suitable for motor drive applications. In this paper, different EI topologies are investigated from the efficiency perspective, including the effect of employing Silicon Carbide...

  15. Analysis and control of novel split-winding doubly salient permanent magnet motor for adjustable speed drive

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, a novel split-winding doubly salient permanentmagnet (DSPM) motor is proposed and the theoretical and experimental studies on the magnetic field, static characteristics and control strategy of this motor are carried out. The steady-state and dynamic models are presented and the output power equation is derived. The feasibility of extending the operation range of the DSPM motor by using split-windings is proved. The finite element method is used to analyze the magnetic field, in which the leakage flux outside the stator circumference is taken into account. Based on the operation principle and the static characteristics of the motor, the control strategy and scheme are developed and implemented in a microcomputer-based controller. According to the features of the 4-phase 8/6-pole DSPM motor, a half-bridge power converter without neutral is adopted to reduce the number of power devices and to eliminate the problem of voltage unbalance in the split capacitors. The experimental results on the prototype machine not only verify the theoretical analysis, but also show that the proposed DSPM motor drive possesses good steady-state and dynamic performances, offering high efficiency over wide power range, and that the split-winding topology can effectively extend the operation range of the DSPM motor.

  16. Motor Integrated Variable Speed Drives

    DEFF Research Database (Denmark)

    Singh, Yash Veer

    rectifier at the front end is presented in this thesis and requirements of a buffer stage in the form of ESI is explained in detail. An equivalent circuit and linear model are developed to give the transfer function and control of the ESI based three-phase rectifier. In this thesis a power converter......A new trend in the variable speed drives (VSDs) is to develop fully integrated systems, which lead to low-cost products with shorter design cycles. Motor Integrated design of VSDs will reduce cable length to connect drive with machine windings and installation time for end user. The electric drives...... when it comes to the development of any kind of power converter topology for power electronic applications. Concerning the use of a power converter in motor integrated VSDs, the first two mentioned aspects receive an even greater im-portance. Power converter design for integrated drives poses a host...

  17. Robust Non-Linear Direct Torque and Flux Control of Adjustable Speed Sensorless PMSM Drive Based on SVM Using a PI Predictive Controller

    Directory of Open Access Journals (Sweden)

    F. Naceri

    2010-01-01

    Full Text Available This paper presents a new sensorless direct torque control method for voltage inverter – fed PMSM. The control methodis used a modified Direct Torque Control scheme with constant inverter switching frequency using Space Vector Modulation(DTC-SVM. The variation of stator and rotor resistance due to changes in temperature or frequency deteriorates theperformance of DTC-SVM controller by introducing errors in the estimated flux linkage and the electromagnetic torque.As a result, this approach will not be suitable for high power drives such as those used in tractions, as they require goodtorque control performance at considerably lower frequency. A novel stator resistance estimator is proposed. The estimationmethod is implemented using the Extended Kalman Filter. Finally extensive simulation results are presented to validate theproposed technique. The system is tested at different speeds and a very satisfactory performance has been achieved.

  18. Speed of adjustment: Evidence from Borsa Istanbul

    Directory of Open Access Journals (Sweden)

    Emrah Arioglu

    2014-06-01

    Full Text Available In this study, we investigate the speed of adjustment for leverage ratios of firms listed on Borsa Istanbul, in order to investigate the prediction of the trade-off theory, regarding capital structure rebalancing. For this purpose, we estimate the speed of adjustment by using Generalized Method of Moments system estimation technique. The results of this estimation suggest the speed of adjustment as approximately 29%. This significant speed of adjustment is consistent with the prediction of trade-off theory, which suggests that firms follow target capital structures and when the firms' leverage ratios deviate from these targets; they make financial decisions with the goal of closing the gap between the previous year's leverage and target leverage of the current period.

  19. Flat belt continuously variable high speed drive

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley turbine'' (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the turbine'' corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the turbine'' belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  20. Auditory feedback influences perceived driving speeds.

    Science.gov (United States)

    Horswill, Mark S; Plooy, Annaliese M

    2008-01-01

    Reducing the level of internal noise is seen as a goal when designing modern cars. One danger of such a philosophy is that one is systematically attempting to alter one of the cues that can be used by drivers to estimate speed and this could bias speed judgments and driving behaviour. Seven participants were presented with pairs of video-based driving scenes and asked to judge whether the second scene appeared faster or slower than the first (2-alternative forced-choice task using the method of constant stimuli). They either heard in-car noise at the level it occurred in the real world or reduced in volume by 5 dB. The reduction in noise led to participants judging speeds to be significantly slower and this effect was evident for all participants. This finding indicates that, when in-car noise is attenuated, drivers are likely to underestimate their speed, potentially encouraging them to drive faster and placing them at greater risk of crashing.

  1. Self-Tuning Speed Regulator for CVC Induction Motor Drive

    DEFF Research Database (Denmark)

    Bidstrup, N.; Rasmussen, Henrik; Knudsen, Torben

    1994-01-01

    A self-tuning speed regulator for a current vector controlled induction motor drive has been designed.......A self-tuning speed regulator for a current vector controlled induction motor drive has been designed....

  2. To the Problem of Electromechanical Interaction in Elevators with Controlled Electric Drive and Fuzzy Speed Controller

    Directory of Open Access Journals (Sweden)

    A. S. Koval

    2010-01-01

    Full Text Available The paper considers problems concerning electromechanical interaction in elevators with an adjustable asynchronous electric drive equipped with the vector control systems under direct torque control and direct torque control with pulse-width modulator. A mathematical description of electromechanical elevator system with due account of nonlinearity of the worm gear is given in the paper. The paper presents a simplified circuit design of a control system with a fuzzy speed controller. It has been established that the factor of electromechanical interaction in electromechanical system with the adjustable asynchronous electric drive and an fuzzy speed controller is within the range which corresponds to existence of the essential electromechanical interaction.

  3. Speed-calming measures and their Effect on driving speed

    DEFF Research Database (Denmark)

    Agerholm, Niels; Knudsen, Daniel; Variyeswaran, Kajan

    2017-01-01

    Speeding increases the risk and severity of accidents, especially for vulnerable road users. Hence, minimisation of speeding in built-up areas is vital. Some countries widely use speed-calming measures (SCs). Documentation shows that SCs reduce speeding considerably although various types...... and designs of SCs affect this reduction. This paper includes studies of the effects from establishment of sinus speed humps of height 10 cm and length 950 cm and chicanes (with a free carriageway width of 5,30 cm and a length between the 0.5 m wide obstacles of 18 m) as a before/after study where the speed...... pattern after establishing SCs is compared with the one before. Floating Car Data used for analyses includes 3,216 trips passing one/more SCs. The main results are that the effect from SCs decreases with the distance from the SCs and that a clear pattern is hard to establish above 75 m from the SC...

  4. Rotor speed estimation for indirect stator flux oriented induction motor drive based on MRAS scheme

    Directory of Open Access Journals (Sweden)

    Youssef Agrebi

    2007-09-01

    Full Text Available In this paper, a conventional indirect stator flux oriented controlled (ISFOC induction motor drive is presented. In order to eliminate the speed sensor, an adaptation algorithm for tuning the rotor speed is proposed. Based on the model reference adaptive system (MRAS scheme, the rotor speed is tuned to obtain an exact ISFOC induction motor drive. The reference and adjustable models, developed in stationary stator reference frame, are used in the MRAS scheme to estimate induction rotor peed from measured terminal voltages and currents. The IP gains speed controller and PI gains current controller are calculated and tuned at each sampling time according to the new estimated rotor speed. The proposed algorithm has been tested by numerical simulation, showing the capability of driving active load; and stability is preserved. Experimental results obtained with a general-purpose 1-kW induction machine are presented showing the effectiveness of the proposed approach in terms of dynamic performance.

  5. Robust Adaptive Speed Control of Induction Motor Drives

    DEFF Research Database (Denmark)

    Bidstrup, N.

    This thesis concerns speed control of current vector controlled induction motor drives (CVC drives). The CVC drive is an existing prototype drive developed by Danfoss A/S, Transmission Division. Practical tests have revealed that the open loop dynamical properties of the CVC drive are highly...... dependent of the operating point, which is characterised by the speed and load. If the requirements to the controller performance is large, then it is difficult to maintain specified controller performance with a fixed controller, because of the open loop variations. An auto-tuner based on least squares......, (LS) identification and generalized predictive control (GPC) has been implemented and tested on the CVC drive. Allthough GPC is a robust control method, it was not possible to maintain specified controller performance in the entire operating range. This was the main reason for investigating truly...

  6. Pitch Based Wind Turbine Intelligent Speed Setpoint Adjustment Algorithms

    Directory of Open Access Journals (Sweden)

    Asier González-González

    2014-06-01

    Full Text Available This work is aimed at optimizing the wind turbine rotor speed setpoint algorithm. Several intelligent adjustment strategies have been investigated in order to improve a reward function that takes into account the power captured from the wind and the turbine speed error. After different approaches including Reinforcement Learning, the best results were obtained using a Particle Swarm Optimization (PSO-based wind turbine speed setpoint algorithm. A reward improvement of up to 10.67% has been achieved using PSO compared to a constant approach and 0.48% compared to a conventional approach. We conclude that the pitch angle is the most adequate input variable for the turbine speed setpoint algorithm compared to others such as rotor speed, or rotor angular acceleration.

  7. Speed Regulated Continuous DTC Induction Motor Drive in Field Weakening

    Directory of Open Access Journals (Sweden)

    MATIC, P.

    2011-02-01

    Full Text Available The paper describes sensorless speed controlled continuous Direct Torque Control (DTC Induction Motor (IM drive in the field weakening regime. Drive comprises an inner torque loop and an outer speed loop. Torque control is based on Proportional - Integral (PI controller with adaptive Gain Scheduling (GS parameters. The GS PI control provides full DC link voltage utilization and a robust disturbance rejection along with a fast torque response. Outer speed loop has a PI regulator with the gains selected so as to obtain a fast and strictly aperiodic response. Proposed drive fully utilizes the available DC bus voltage. The paper comprises analytical considerations, simulation results, and detailed description of the implementation steps. Experimental verification of the proposed solution is conducted on a fixed point Digital Signal Processor (DSP platform.

  8. A New Low-Cost Hybrid Switched Reluctance Motor for Adjustable-Speed Pump Applications

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Rasmussen, Peter Omand; Watkins, Steve;

    2011-01-01

    This paper presents a new low-cost hybrid switched reluctance (HSR) motor intended for use in adjustable-speed pump drive systems. The motor is a single-phase motor, driven by a unipolar converter, which uses both the reluctance torque and the permanent magnet interaction torque. Compared...... systems for low-cost applications. Finite-element models are used to analyze and predict the motor's performance. The proposed motor drive system has been fabricated, and its performance has been tested in the laboratory. These experimental results are also presented....

  9. Speed Control of Bldc Motor Drive By Using Pid Controllers

    Directory of Open Access Journals (Sweden)

    Y.Narendra Kumar,

    2014-04-01

    Full Text Available This paper mainly deals with the Brushless DC (BLDC motor speed driving systems have sprouted in various small scale and large scale applications like automobile industries, domestic appliances etc. This leads to the development in Brushless DC motor (BLDCM. The usage of BLDC Motor enhances various performance factors ranging from higher efficiency, higher torque in low-speed range, high power density ,low maintenance and less noise than other motors. The BLDC Motor can act as an alternative for traditional motors like induction and switched reluctance motors. In this paper PID controller is implemented with speed feedback loop and it is observe that torque ripples are minimized. Simulation is carried out using MATLAB / SIMULINK. The results show that the performance of BLDC Motor is quite satisfactory for various loading conditions. Brushless DC motor drives are typically employed in speed controlled applications.

  10. Urban Traffic Eco-Driving: Speed Advisory Tracking

    OpenAIRE

    De Nunzio, Giovanni; Canudas De Wit, Carlos; Moulin, Philippe

    2014-01-01

    International audience; The evaluation of the benefits of an Eco-Driving assistance system is carried out in the urban environment in presence of traffic lights. The traffic evolution is modeled macroscopically with the Urban Variable-Length Model in a variable speed limits framework. Under the assumption of equal boundary flows, the vehicles in a road section dispose themselves according to well defined equilibrium conditions which are dependent on the traveling speed in the free-flow part o...

  11. Sliding Mode Speed Control for DC Drive Systems

    OpenAIRE

    Guldemir, H.

    2003-01-01

    In this study, the Sliding Mode Control theory of the Variable Structure System has been applied to the speed control of a de motor. The dynamic performance of the sliding mode speed control system has been studied against system parameter variations and external load disturbance and the simulation results are given. The application of the sliding mode control theory to controller design for DC drive control system shows a robust system performance.

  12. Wind generator with electronic variable-speed drives

    Energy Technology Data Exchange (ETDEWEB)

    David, A.; Buchheit, N.; Jakobsen, H.

    1996-12-31

    Variable speed drives have been inserted between the network and the generator on certain recent wind power facilities. They have the following advantages: the drive allows the wind generator to operate at low speed with a significant reduction in acoustic noise, an important point if the facilities are sited near populated areas; the drive optimizes energy transfer, providing a gain of 4 to 10 %; the drive can possibly replace certain mechanical parts (the starting system and it in some cases, the reduction gear); the drive not only provides better transient management in relation to the network for less mechanical stress on the wind generator, it is also able to control reactive power. One commercial drive design sold by several manufacturers has already been installed on several wind generators with outputs of between 150 and 600 kw. In addition, such a solution is extremely well suited to mixed renewable energy systems. This design uses two inverse rectifier type converters and can therefore exchange energy in both directions. The equivalent drive with a single IGBT converter on the motor side and a diode converter on the network side is the solution most widely adopted throughout industry (with more than 50, 000 units installed in France per year). It still remains to be seen whether such a solution could be profitable in wind generator application (since the cost of the drive is quite high). This technical analysis is more destined for the converter-machine assembly specialists and is presented in this document, paying particular attention as it does to the modelling of the `wind energy - generator - drive - network` assembly, the associated drive command and control strategies and the simulations obtained during various transients. A 7.5 kW test bed has been installed in the Laboratoire d`Electronique de Puissance de Clamart, enabling tests to be carried out which emulate the operation of a wind generator.

  13. Sensorless speed Control including Zero Speed on Non Salient PM Synchronous Drives

    DEFF Research Database (Denmark)

    Rasmussen, Henrik

    2006-01-01

    This paper presents a position sensorless drive of non salient pole PM synchronous motors for all speeds including zero speed. Using adaptive Lyapunov design a new approach for the design of an observer is developed. The resulting scheme leads to a nonlinear full order observer for the motor stat...

  14. Sensorless Speed Control including zero speed of Non Salient PM Synchronous Drives

    DEFF Research Database (Denmark)

    Rasmussen, Henrik

    2005-01-01

    This paper presents a position sensorless drive of non salient pole PM synchronous motors for all speeds including zero speed. Using adaptive Lyapunov design a new approach for the design of an observer is developed. The resulting scheme leads to a nonlinear full order observer for the motor stat...

  15. Sensorless Speed Control including zero speed of Non Salient PM Synchronous Drives

    DEFF Research Database (Denmark)

    Rasmussen, Henrik

    This paper presents a position sensorless drive of non salient pole PM synchronous motors for all speeds including zero speed. Using adaptive Lyapunov design a new approach for the design of an observer is developed. The resulting scheme leads to a nonlinear full order observer for the motor states...... including the rotor speed. Assuming motor parameters known the design achieves stability with guaranteed region of attraction even at zero speed. The control method is made robust at zero and low speed by changing the direct vector current component to a value different from zero. In order to verify...

  16. Flat belt continuously variable high speed drive. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kumm, E.L.

    1992-02-01

    A study was undertaken at Kumm Industries funded by DOE in the NBS/DOE Energy-Related Inventions Program starting in August 1990 to design, construct and test a novel very high speed flat belt drive. The test arrangement as shown in Figure 1 consists of a multiple belt-pulley configuration that transmits power from a low speed (2000--4000 RPM) input to a small pulley ``turbine`` (27,000 to 55,000 RPM) and then to the low speed output variable radius pulley (2000--5000 RPM) via a special self-active tensioner. Transmitting 25 HP to and from the ``turbine`` corresponds to obtaining 50 HP in one direction only in a possible turbo compounded engine application. The high speed of the ``turbine`` belts, i.e. 100 meters/sec. at 55,000 RPM, while transferring substantial power is a new much higher operating regime for belts. The study showed that the available belts gave overall test rig efficiencies somewhat above 80% for the higher speeds (50,000 RPM) and higher powers (corresponding to above 90% in the turbocompound application) and a significantly better efficiencies at slightly lower speeds. The tests revealed a number of improved approaches in the design of such high speed drives. It appears that there is considerable possibility for further improvement and application of such equipment.

  17. Application of drive circuit based on L298N in direct current motor speed control system

    Science.gov (United States)

    Yin, Liuliu; Wang, Fang; Han, Sen; Li, Yuchen; Sun, Hao; Lu, Qingjie; Yang, Cheng; Wang, Quanzhao

    2016-10-01

    In the experiment of researching the nanometer laser interferometer, our design of laser interferometer circuit system is up to the wireless communication technique of the 802.15.4 IEEE standard, and we use the RF TI provided by Basic to receive the data on speed control system software. The system's hardware is connected with control module and the DC motor. However, in the experiment, we found that single chip microcomputer control module is very difficult to drive the DC motor directly. The reason is that the DC motor's starting and braking current is larger than the causing current of the single chip microcomputer control module. In order to solve this problem, we add a driving module that control board can transmit PWM wave signal through I/O port to drive the DC motor, the driving circuit board can come true the function of the DC motor's positive and reversal rotation and speed adjustment. In many various driving module, the L298N module's integrated level is higher compared with other driver module. The L298N model is easy to control, it not only can control the DC motor, but also achieve motor speed control by modulating PWM wave that the control panel output. It also has the over-current protection function, when the motor lock, the L298N model can protect circuit and motor. So we use the driver module based on L298N to drive the DC motor. It is concluded that the L298N driver circuit module plays a very important role in the process of driving the DC motor in the DC motor speed control system.

  18. Brushless DC motor Drive during Speed regulation with Current Controller

    Directory of Open Access Journals (Sweden)

    Bhikshalu Manchala

    2015-04-01

    Full Text Available Brushless DC Motor (BLDC is one of the best electrical drives that have increasing popularity, due to their high efficiency, reliability, good dynamic response and very low maintenance. Due to the increasing demand for compact & reliable motors and the evolution of low cost power semiconductor switches and permanent magnet (PM materials, brushless DC motors become popular in every application from home appliances to aerospace industry. The conventional techniques for controlling the stator phase current in a brushless DC drive are practically effective in low speed and cannot reduce the commutation torque ripple in high speed range. This paper presents the PI controller for speed control of BLDC motor. The output of the PI controllers is summed and is given as the input to the current controller. The BLDC motor is fed from the inverter where the rotor position and current controller is the input. The complete model of the proposed drive system is developed and simulated using MATLAB/Simulink software. The operation principle of using component is analysed and the simulation results are presented in this to verify the theoretical analysis.

  19. Design of an Ultimate High Speed Electrical Drive System

    Directory of Open Access Journals (Sweden)

    C. Vishnu Kiran

    2014-05-01

    Full Text Available New emerging applications in the areas of portable power generation, small turbocompressors and spindles require the development of ultrahigh-speed, low power electrical drives. A 500 000 r/min, 100 W electrical drive system is presented. Because of the ultrahigh-speed requirements, standard machine design and power electronic topology choices no longer apply and the complete drive system has to be considered. A permanent magnet machine with a slotless litz-wire winding is used, which results in a low motor inductance and a high fundamental machine frequency. Three different combinations of power electronic topologies and commutation strategies have been experimentally investigated. A voltage source inverter with block commutation and an additional dc–dc converter is selected as the most optimal choice for the power electronics interface as it results in the lowest volume of the entire drive system due to lower switching losses, no heat sink cooling required, a small number of semiconductor devices, and relatively simple control implementation in a low cost digitalsignal processor.

  20. Speed estimator for induction motor drive based on synchronous speed tracking

    Indian Academy of Sciences (India)

    S B Bodkhe; M V Aware; J G Chaudhari; J G Agrawal

    2015-06-01

    This paper presents a new open-loop speed estimation method for a three-phase induction motor drive. The open-loop speed estimators available in literature have the advantage of reduced computational stress over the observers but they share a common limitation of being largely dependent on flux and machine parameters. They involve integrations and differentiation in the algorithm that leads to serious error in estimation when subject to different operating conditions. The proposed estimator is based on synchronous speed tracking and is cost-effective. It is immune to any variation in machine parameters and noise. The synchronous speed is computed from stator frequency which is estimated on-line using the stator current signals. A unique, non-adaptive method for estimation of stator frequency within one-sixteenth of time period is also proposed to enhance the speed of estimation. Computer simulation and experimentation on a 2.2 kW Field oriented controlled induction motor drive is carried out to verify the performance of proposed speed estimator. The results show excellent response over a wide range of rotor speed in both directions including low speed and under different operating conditions. This confirms the effectiveness of the proposed method.

  1. Speed Ratio Prediction and Performance Analysis of Single Ball Traction Drive for CVT

    Directory of Open Access Journals (Sweden)

    Kunal S. Marathe

    2014-06-01

    Full Text Available Drives are basically used to transmit power and speed from the prime mover to the machine. The power transmission and speed reduction between the prime-mover and the driven machine can be achieved by using conventional drives like Belt drive, Rope drive, Chain drive, Gears, etc. with their numerous advantages and disadvantages. There are many machines and mechanical units that under varying circumstances make it desirable to be able to drive at a barely perceptible speed, an intermediate speed or a high speed. Thus an infinitely variable (step less speed variation in which it is possible to get any desirable speed. Some mechanical, hydraulic, drives serve as such step less drives. However the torque versus speed characteristics of these drives do not match torque at low speeds. Hence the need of a step less or infinitely variable speed drive came into existence. The drive presented by the end of this research work is single ball traction drive for continuously variable transmission systems. Dissertation includes the brief history of existing drives, speed prediction methodology and performance analysis of the drive developed.

  2. VCA Direct-Drive High Speed and Precision XY Table

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xingyu; FENG Xiaomei; ZHANG Dawei

    2007-01-01

    In order to compensate for the limitation of conventional XY table used in semiconductor integrated circuits(IC) packaging and improve its speed and accuracy, a voice coil actuator (VCA)direct-drive high-speed and precision positioning XY table used in wire bonder was proposed. Also, a novel flexible decoupling mechanism was used in the positioning table, and the small moving mass enabled the positioning table to move at high speed and precision. XY table deformation interference caused by assembly error and instant interference generated by dynamic load moving with high speed and acceleration can be eliminated through the flexible decoupling mechanism. Considering the positioning table as lumped mass spring system, the dynamic equations of the mechanical sys-tem and the VCA were built according to the Newton mechanics principle and electromagnetic theory. Then the electromechanical coupling control model of the system was created through Laplace transform. Based on displacement PID controller, the Icop-locked controlling algorithm of the positioning system was investigated. The dynamic control algorithm effectively improved the system dynamic performance. The precision test of the prototype machine was carried out, and the results val-idated the correctness of the model and the theory. Compared with traditional XY table, the tablehas higher speed, acceleration and positioning accuracy.

  3. Harmonic Calculation Toolbox in Industry Application for Adjustable Speed Drive

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Blaabjerg, Frede; Hansen, Steffan

    2004-01-01

    Previous to electrical installation of large power non-linear loads, a comprehensive design-study is often required in order to determine if the overall installation complies with international regulations in respect to harmonics. Current THD voltage distortion and power factor are just few...... of an off-line database and new interpolation techniques very good results have been achieved. The final results obtained are very close to the measurements on real applications and the toolbox can be used for future ASD designs and installations....

  4. Harmonic Calculation Software for Industrial Applications with Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Asiminoaei, Lucian; Hansen, S.; Blaabjerg, Frede

    2005-01-01

    This paper describes the evaluation of a new harmonic software. By using a combination of a pre-stored database and new interpolation techniques the software can very fast provide the harmonic data on real applications. The harmonic results obtained with this software have acceptable precision even...... with limited input data. The evaluation concludes here that this approach is very practical compared to other advanced harmonic analysis methods. The results are supported by comparisons of calculations and measurements given in an industrial application....

  5. New Drive Train Concept with Multiple High Speed Generator

    Science.gov (United States)

    Barenhorst, F.; Serowy, S.; Andrei, C.; Schelenz, R.; Jacobs, G.; Hameyer, K.

    2016-09-01

    In the research project RapidWind (financed by the German Federal Ministry for Economic Affairs and Energy under Grant 0325642) an alternative 6 MW drive train configuration with six high-speed (n = 5000 rpm) permanent magnet synchronous generators for wind turbine generators (WTG) is designed. The gearbox for this drive train concept is assembled with a six fold power split spur gear stage in the first stage, followed by six individual 1 MW geared driven generators. Switchable couplings are developed to connect and disconnect individual geared generators depending on the input power. With this drive train configuration it is possible to improve the efficiency during partial load operation, increasing the energy yield about 1.15% for an exemplary low-wind site. The focus of this paper is the investigation of the dynamic behavior of this new WTG concept. Due to the high gear ratio the inertia relationship between rotor and generator differs from conventional WT concepts, possibly leading to intensified vibration behavior. Moreover there are switching procedures added, that might also lead to vibration issues.

  6. Analysis of Variable Speed PFC Chopper Fed BLDC Motor Drive

    Directory of Open Access Journals (Sweden)

    A Jeya Selvan Renius

    2015-02-01

    Full Text Available This paper provides the detailed analysis of the DC-DC chopper fed Brushless DC motor drive used for low-power applications. The various methods used to improve the power quality at the ac mains with lesser number of components are discussed. The most effective method of power quality improvement is also simulated using MATLAB Simulink. Improved method of speed control by controlling the dc link voltage of Voltage Source Inverter is also discussed with reduced switching losses. The continuous and discontinuous modes of operation of the converters are also discussed based on the improvement in power quality. The performance of the most effective solution is simulated in MATLAB Simulink environment and the obtained results are presented.

  7. Musculoskeletal analysis of driving fatigue: The influence of seat adjustments

    DEFF Research Database (Denmark)

    Majid, Noor Aliah binti Abdul; Abdullah, Mohd Fareez Edzuan; Jamaludin, Mohd Syahmi

    2013-01-01

    Main causes for discomfort experienced by vehicle drivers during driving were investigated using a rigid-body model originally developed in the AnyBody Modeling System [1]. The interactions between the human body and the car-seat in various combinations of seat-pan/backrest inclinations and the e...

  8. Research on Control System of Spindle Drive for High Speed Spinning Machine

    Institute of Scientific and Technical Information of China (English)

    魏建

    2001-01-01

    Through analyzing the principle of spindle drive of winding mechanism for high speed spinning machine,the article not only describes a kind of mode of spindle drive for take-up motion on the basis of control method of constant velocity winding, but also introduces the design technique of software and hardware for the control system of mechatronics of spindle drive mode for take- up motion on the basis of constant velocity winding for high speed spinning machine with single-chip microcomputer. The mathematical model to describe the spindle rotating speed is established. It is an important technology for high speed spinning machine and provides a feasible application way.

  9. Intelligent speed control and effects on driving behaviour

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Hogema, J.H.

    1999-01-01

    Supporting the driver in conducting his nowadays demanding task is a promising means to get the maximum out of the road system with respect to both efficiency and safety. With respect to safety, speed management is a main issue. Police enforcement of speeding is one approach, preventing high speeds

  10. The effects of anti-speeding advertisements on the simulated driving behaviour of young drivers.

    Science.gov (United States)

    Plant, Bernice R C; Irwin, Julia D; Chekaluk, Eugene

    2017-03-01

    Recent examinations of road safety communications, including anti-speeding advertisements, have considered the differential effects of positive and negative emotional appeals on driver behaviour. However, empirical evaluations of anti-speeding messages have largely relied on measures of viewers' reported intentions to comply with speed limits and the self-reported driving behaviour of viewers post-exposure, which might not be indicative of the direct effects that these messages have on real-world driving behaviour. The current research constitutes a first empirical evaluation of different real-world anti-speeding advertisements, as measured by their effects on young drivers' speeding behaviour, using a driving simulator. Licensed drivers (N=116) aged 17-25 years completed driving measures prior to, immediately following, and 7-10days after viewing one of four social marketing advertisements. Results indicated that young drivers' average driving speeds were modestly reduced immediately after they viewed an anti-speeding advertisement that depicted social consequences for speeding and employed a positive emotional appeal when compared to an emotion-matched control advertisement; however, this effect was not found for the anti-speeding advertisement depicting a crash. Interestingly, the results based on reported intentions to reduce speeding predicted the opposite pattern of results. However, there was no evidence that the immediate changes to speeding were maintained 7-10days later, and prompts during Phase 2 did not appear to have an effect. The implications of these findings for road safety advertisements targeting young drivers are discussed.

  11. Jump Testing and the Speed of Market Adjustment

    DEFF Research Database (Denmark)

    Rasmussen, Torben B.

    for high-frequency transaction data. To capture these microstructure effects, this paper suggests a model in which market prices adjust gradually to jumps in the underlying effcient price. A case study illustrates the empirical relevance of the model, and the performance of different jump tests...... is investigated here and in a simulation study. Evidence indicates that tests based on the largest of scaled price increments perform better than tests comparing measures of variability. Resolving the matter by testing at lower frequencies turns out to be less straightforward.......Asymptotic properties of jump tests rely on the property that any jump occurs within a single time interval no matter what the observation frequency is. Market microstructure effects in relation to news-induced revaluation of the underlying variable is likely to make this an unrealistic assumption...

  12. New Optimized Soft Computing Speed Controller for PMSM Drive

    Directory of Open Access Journals (Sweden)

    A. El Janati El Idrissi

    2014-02-01

    Full Text Available This study proposes a soft computing speed controller where recurrent neural network speed controller is trained by genetic extended kalman filter, based on a predetermined genetic Proportional Integral (PI controller. A genetic PI gives to this proposed speed controller exact values without mathematical equations, unlike the classical PI who is need for it necessary. With this proposed method the results of simulation obtained is as they are of real state of the Permanent Magnet Synchronous Motor (PMSM. The harmonic ripples of speed response are also minimized with Genetic Extended Kalman Filter (GEKF and Neural Network Space Vector Modulation (NNSVM. This fusion between the Artificial Intelligence (AI and optimized method of the extended kalman filter gives more superiority to the method proposed, like shows the simulations results compared to classical Neural Network Controller (NNC.

  13. Variable-Speed, Robust Synchronous Reluctance Machine Drive Systems

    DEFF Research Database (Denmark)

    Wang, Dong

    The synchronous reluctance machine drive is getting more and more interests from the industrial side, since it can provide higher system energy efficiency than traditional inverter-fed induction machine drive systems with similar production cost. It is considered as a good candidate for super...... premium efficiency machine and commercial products are available in the market. The research work in this dissertation aims at developing a simple, compact and robust synchronous reluctance machine drive system that can provide satisfactory performance with optimized system energy efficiency at various...... working conditions. Field oriented control assisted with various position estimation algorithms is in-vestigated. Position sensing via machine flux linkage is implemented with the assistance of a widely used flux observer. Experiments show that it may not always work properly and system oscillation...

  14. Doubly Fed Drives for Variable Speed Wind Turbines

    DEFF Research Database (Denmark)

    Lindholm, Morten

    2004-01-01

    This thesis deals with the use of variable speed wind turbines. Different wind turbine generator topologies are described. In particular, the reduced variable speed turbine, which uses a doubly fed induction generator, is covered. An overview of the power electronic inverters of interest...... in the machine is nearly constant. This means that changes of either the flux or torque producing current in the rotor circuit is limited by the transient time constant of the machine. A 40 kW laboratory model with a doubly fed induction generator and a 3-level neutral point clamped back to back power converter...... is constructed. Adaptive active flters are used to reduce harmonics and slip harmonics in the stator current. The flters are implemented in both inverters. The active flters reduce the stator harmonics by 20-30 dB. The flters can reduce the slip harmonics at variable speed....

  15. Effects of human-machine interface design for intelligent speed adaptation on driving behavior and acceptance

    NARCIS (Netherlands)

    Rook, A.M.; Hogema, J.H.

    2005-01-01

    The effects of human-machine interface (HMI) design for intelligent speed adaptation (ISA) on driving behavior and acceptance were measured in a moving-base research driving simulator. Sixty-four experienced drivers participated in two simulator experiments (32 in each). During the simulated runs wi

  16. Speed-Sensorless DTC-SVM for Matrix Converter Drives With Simple Non-Linearity Compensation

    DEFF Research Database (Denmark)

    Lee, Kyo-Beum; Blaabjerg, Frede; Yoon, Tae-Woong

    2005-01-01

    This paper presents a new method to improve sensorless performance of matrix converter drives using a parameter estimation scheme. To improve low-speed sensorless performance, the non-Iinearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching devic...

  17. Speed-Sensorless DTC-SVM for Matrix Converter Drives With Simple Nonlinearity Compensation

    DEFF Research Database (Denmark)

    Lee, Kyo Beum; Blaabjerg, Frede; Yoon, Tae-Woong

    2007-01-01

    This paper presents a new method to improve the sensorless performance of matrix converter drives using a parameter estimation scheme. To improve low-speed sensorless performance, the nonlinearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching de...

  18. Speed Loop Control of PMSM Driving Electric Vehicle

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong;

    2011-01-01

    Various simulation models are set up and closed speed loop control strategy of PMSM is proposed based on flux weakening control in this paper. First the model of maximum torque per ampere(MTPA) is modeled based on mathematical models and gave the corresponding simulation tests. Second the formula...

  19. Variable-Speed, Robust Synchronous Reluctance Machine Drive Systems

    DEFF Research Database (Denmark)

    Wang, Dong

    algorithm, the proposed machine inductance in-dependent position estimation algorithm shows better dynamic response against the step load changes but requires more accurate signal sampling in steady state. Therefore, the flux linkage based position estimation algorithm with adaptive PI controllers......The synchronous reluctance machine drive is getting more and more interests from the industrial side, since it can provide higher system energy efficiency than traditional inverter-fed induction machine drive systems with similar production cost. It is considered as a good candidate for super...... inductance independency. High frequency signal injection based on duty cycle shifting is introduced, which can achieve signal injection without sacrificing the maximum allowable fundamental voltage for torque production, so that the machine induct-ance independent position estimation algorithm can...

  20. Speed Sensorless Induction Motor Drives for Electrical Actuators: Schemes, Trends and Tradeoffs

    Science.gov (United States)

    Elbuluk, Malik E.; Kankam, M. David

    1997-01-01

    For a decade, induction motor drive-based electrical actuators have been under investigation as potential replacement for the conventional hydraulic and pneumatic actuators in aircraft. Advantages of electric actuator include lower weight and size, reduced maintenance and operating costs, improved safety due to the elimination of hazardous fluids and high pressure hydraulic and pneumatic actuators, and increased efficiency. Recently, the emphasis of research on induction motor drives has been on sensorless vector control which eliminates flux and speed sensors mounted on the motor. Also, the development of effective speed and flux estimators has allowed good rotor flux-oriented (RFO) performance at all speeds except those close to zero. Sensorless control has improved the motor performance, compared to the Volts/Hertz (or constant flux) controls. This report evaluates documented schemes for speed sensorless drives, and discusses the trends and tradeoffs involved in selecting a particular scheme. These schemes combine the attributes of the direct and indirect field-oriented control (FOC) or use model adaptive reference systems (MRAS) with a speed-dependent current model for flux estimation which tracks the voltage model-based flux estimator. Many factors are important in comparing the effectiveness of a speed sensorless scheme. Among them are the wide speed range capability, motor parameter insensitivity and noise reduction. Although a number of schemes have been proposed for solving the speed estimation, zero-speed FOC with robustness against parameter variations still remains an area of research for speed sensorless control.

  1. Brushless DC motor Drive during Speed regulation with Current Controller

    OpenAIRE

    Bhikshalu Manchala; T.Amar Kiran

    2015-01-01

    Brushless DC Motor (BLDC) is one of the best electrical drives that have increasing popularity, due to their high efficiency, reliability, good dynamic response and very low maintenance. Due to the increasing demand for compact & reliable motors and the evolution of low cost power semiconductor switches and permanent magnet (PM) materials, brushless DC motors become popular in every application from home appliances to aerospace industry. The conventional techniques for controlling...

  2. Driving Skills of Young Adults with Developmental Coordination Disorder: Regulating Speed and Coping with Distraction

    Science.gov (United States)

    de Oliveira, Rita F.; Wann, John P.

    2011-01-01

    In two experiments, we used an automatic car simulator to examine the steering control, speed regulation and response to hazards of young adults with developmental coordination disorder (DCD) and limited driving experience. In Experiment 1 participants either used the accelerator pedal to regulate their speed, or used the brake pedal when they…

  3. Rotor Speed and Stator Resistance Identification Scheme for Sensorless Induction Motor Drives

    Directory of Open Access Journals (Sweden)

    Xinzhi Liu

    2013-01-01

    Full Text Available This paper proposes a rotor speed identification method for sensorless induction motor drives based on a model reference adaptive system (MRAS. In this scheme, the error between estimated stator current and real stator current is regarded as the system error to estimate the rotor speed. Adaptive full-order flux observers for estimating the rotor speed are developed using Lyapunov’s stability theory. The stator resistance identification algorithm is developed with rotor speed estimating method in a systematic manner. Because of the stator resistance varies with inner temperature of the motor, the influence of motor speed estimation due to stator resistance identification error is analyzed. The error compensation method for stator resistance estimation is also proposed. Simulation and experimental results show the good performance for the proposed scheme in speed and robustness for sensorless induction motor drives.

  4. Speed Estimators Using Stator Resistance Adaptation for Sensorless Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Hau Huu Vo

    2016-01-01

    Full Text Available The paper describes speed estimators for a speed sensorless induction motor drive with the direct torque and flux control. However, the accuracy of the direct torque control depends on the correct information of the stator resistance, because its value varies with working conditions of the induction motor. Hence, a stator resistance adaptation is necessary. Two techniques were developed for solving this problem: model reference adaptive system based scheme and artificial neural network based scheme. At first, the sensorless control structures of the induction motor drive were implemented in Matlab-Simulink environment. Then, a comparison is done by evaluating the rotor speed difference. The simulation results confirm that speed estimators and adaptation techniques are simple to simulate and experiment. By comparison of both speed estimators and both adaptation techniques, the current based model reference adaptive system estimator with the artificial neural network based adaptation technique gives higher accuracy of the speed estimation.

  5. A speed estimation of sensorless control for asymmetrical parameter type two-phase induction motor drives

    Directory of Open Access Journals (Sweden)

    Nuttapong Muangchan

    2015-06-01

    Full Text Available This paper presents the concept of a speed estimation of sensorless control for asymmetrical parameter type two-phase induction motor drive, by using the adaptive observer system. The motor speed is estimated on the rotor-flux reference frame to simplicity for application. The design guideline of the gain of speed estimate system for a motor has speed change. The experimental results for all test conditions show that the responses of current, torque and speed are stable for the entire operating region.

  6. Variable speed drive as an alternative solution for a micro-hydro power plant

    OpenAIRE

    Akhtar, Malik Usman

    2012-01-01

    This diploma work is mainly focused on developing the control strategy for avariable speed drive as an alternative solution to a micro-hydro power plant. The detailed mathematical model for a micro-hydro system including a Kaplan turbine, mechanical shaft and electrical machines is presented and validated through simulations. A control strategy for an autonomous operation of a doubly-fed induction machine-based drive is developed for a wide range of speed. The drive can operate at a unity pow...

  7. The impact of personality on driving safety among Chinese high-speed railway drivers.

    Science.gov (United States)

    Guo, Ming; Wei, Wei; Liao, Ganli; Chu, Fulei

    2016-07-01

    This study explored the impact of personality traits on driving safety in high-speed railway drivers. A sample of high-speed railway drivers in Beijing (N=214) completed a questionnaire, including information on personality traits and background variables. The NEO Five Factor Inventory (NEO-FFI) was administered to characterize participants based on five personality traits: Neuroticism, Extraversion, Agreeableness, Openness to Experience, and Conscientiousness. The survey data were combined with naturalistic data of accident involvement and risky driving behavior in China. Poisson regression results show that drivers with high Conscientiousness and Extraversion caused fewer accidents. Higher Conscientiousness and lower Agreeableness were related to less frequent risky driving behavior. Education level and age negatively moderated the relation between certain personality traits and driving safety. The findings suggest that personality traits should be considered when selecting and training high-speed railway drivers.

  8. Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Sindhu M R

    2014-12-01

    Full Text Available Variable speed drives are mostly preferred in industries, while considering energy saving, smooth control, flexible operation and fast response. On the other hand, this equipment generates dynamic harmonic distortions in source currents and draws variable reactive power demand depending on variation in load condition. These distortions propagate throughout the system and affect all the loads connected to the point of common coupling. Hence a dynamic harmonic and reactive compensator is necessary to enhance power quality to meet current and voltage distortion limits at point of common coupling as per IEEE standard. The most common choice for adjustable speed drives in industries is three phase voltage source inverter based induction motor drives which uses PWM technique for voltage, frequency and current control. This paper presents harmonic analysis of an induction motor drive in an industrial plant and development of adaptive dynamic harmonic and reactive compensator to improve power quality. A digital controller which is programmed with adaptive Artificial Neural Network (ANN based control algorithm is used for controlling shunt active filter. The simulation and experimental results show that the adaptive shunt active filter provides effective harmonic and reactive compensation in the system under steady state and dynamic load conditions.

  9. A Very Low-Speed Sensorless Induction Motor Drive with Online Stator Resistance identification scheme

    Directory of Open Access Journals (Sweden)

    M. Zaky

    2008-03-01

    Full Text Available Recently, speed sensorless control of induction motor drives received great attention to avoid the different problems associated with direct speed sensors. However, low speed operation with robustness against parameter variations remains an area of research for sensorless systems. Stator resistance is of greatest importance for good operation of speed sensorless systems in low speed region. In this paper, a sliding mode current observer for an induction motor is presented. An estimation algorithm based on this observer in conjunction with Popov's hyper-stability theory is proposed to calculate the speed and stator resistance independently. The proposed speed observer with parallel stator resistance identification is firstly verified by simulation. Experimental results are included as well to demonstrate the good performance of the proposed observer and estimation algorithms at low speed.

  10. Evaluation Research of the Effects of Longitudinal Speed Reduction Markings on Driving Behavior: A Driving Simulator Study.

    Science.gov (United States)

    Ding, Han; Zhao, Xiaohua; Ma, Jianming; Rong, Jian

    2016-11-23

    The objective of this paper is to explore the effects of longitudinal speed reduction markings (LSRMs) on vehicle maneuvering and drivers' operation performance on interchange connectors with different radii. Empirical data were collected in a driving simulator. Indicators-relative speed change, standard deviation of acceleration, and gas/brake pedal power-were proposed to characterize driving behavior. Statistical results revealed that LSRMs could reduce vehicles' travel speed and limit drivers' willingness to increase speed in the entire connector. To probe the impacts of LSRMs, the connecter was split into four even sections. Effects of LSRMs on driving behavior were stronger in the second and the final sections of connectors. LSRMs also enhanced drivers' adaptability in the first three quarters of a connector when the radius was 50 m. Drivers' gas pedal operation would be impacted by LSRMs in the entire connector when the radius was 50 m. LSRMs could only make drivers press brake pedal more frequently in the second section with 80 m and 100 m radius. In the second quarter section of a connector-from the FQP (the first quartile point) to the MC (the middle point of curve)-LSRMs have better effects on influencing vehicle maneuvering and drivers' operation performance.

  11. Energy Efficient Control of High Speed IPMSM Drives - A Generalized PSO Approach

    Directory of Open Access Journals (Sweden)

    GECIC, M.

    2016-02-01

    Full Text Available In this paper, a generalized particle swarm optimization (GPSO algorithm was applied to the problems of optimal control of high speed low cost interior permanent magnet motor (IPMSM drives. In order to minimize the total controllable electrical losses and to increase the efficiency, the optimum current vector references are calculated offline based on GPSO for the wide speed range and for different load conditions. The voltage and current limits of the drive system and the variation of stator inductances are all included in the optimization method. The stored optimal current vector references are used during the real time control and the proposed algorithm is compared with the conventional high speed control algorithm, which is mostly voltage limit based. The computer simulations and experimental results on 1 kW low cost high speed IPMSM drive are discussed in details.

  12. Offset Compound Gear Inline Two-Speed Drive

    Science.gov (United States)

    Stevens, Mark A. (Inventor); Handschuh, Robert F. (Inventor); Lewicki, David G. (Inventor)

    2014-01-01

    A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction.

  13. Theoretical research on hydroviscous speed-adjusting clutch in soft-start of belt conveyor

    Institute of Scientific and Technical Information of China (English)

    ZHOU Man-shan; ZHANG Yuan

    2005-01-01

    Through research on the application of hydroviscous speed-adjusting clutch in belt conveyor, this paper concluded that hydroviscous speed-adjusting clutch has many advantages such as controllable start and stop, overload protection and multi-motor power equilibrium. But its theory when used in large power fan and pump could not meet the needs of belt conveyor soft-start operation. Focusing on the theoretical analysis of the lubrication oil flow needed by the transmission procedure to form the oil-film. Put forward concrete calculation methods of lubrication flow and how to decide number of oil-films used in belt conveyor.

  14. Probability distribution of surface wind speed induced by convective adjustment on Venus

    Science.gov (United States)

    Yamamoto, Masaru

    2017-03-01

    The influence of convective adjustment on the spatial structure of Venusian surface wind and probability distribution of its wind speed is investigated using an idealized weather research and forecasting model. When the initially uniform wind is much weaker than the convective wind, patches of both prograde and retrograde winds with scales of a few kilometers are formed during active convective adjustment. After the active convective adjustment, because the small-scale convective cells and their related vertical momentum fluxes dissipate quickly, the large-scale (>4 km) prograde and retrograde wind patches remain on the surface and in the longitude-height cross-section. This suggests the coexistence of local prograde and retrograde flows, which may correspond to those observed by Pioneer Venus below 10 km altitude. The probability distributions of surface wind speed V during the convective adjustment have a similar form in different simulations, with a sharp peak around ∼0.1 m s-1 and a bulge developing on the flank of the probability distribution. This flank bulge is associated with the most active convection, which has a probability distribution with a peak at the wind speed 1.5-times greater than the Weibull fitting parameter c during the convective adjustment. The Weibull distribution P(> V) (= exp[-(V/c)k]) with best-estimate coefficients of Lorenz (2016) is reproduced during convective adjustments induced by a potential energy of ∼7 × 107 J m-2, which is calculated from the difference in total potential energy between initially unstable and neutral states. The maximum vertical convective heat flux magnitude is proportional to the potential energy of the convective adjustment in the experiments with the initial unstable-layer thickness altered. The present work suggests that convective adjustment is a promising process for producing the wind structure with occasionally generating surface winds of ∼1 m s-1 and retrograde wind patches.

  15. A New High Speed Induction Motor Drive based on Field Orientation and Hysteresis Current Comparison

    Science.gov (United States)

    Ogbuka, Cosmas; Nwosu, Cajethan; Agu, Marcel

    2016-09-01

    This paper presents a new high speed induction motor drive based on the core advantage of field orientation control (FOC) and hysteresis current comparison (HCC). A complete closed loop speed-controlled induction motor drive system is developed consisting of an outer speed and an inner HCC algorithm which are optimised to obtain fast and stable speed response with effective current and torque tracking, both during transient and steady states. The developed model, being speed-controlled, was examined with step and ramp speed references and excellent performances obtained under full load stress. A speed response comparison of the model with the standard AC3 (Field-Oriented Control Induction Motor Drive) of MATLAB Simpower systems shows that the model achieved a rise time of 0.0762 seconds compared to 0.2930 seconds achieved by the AC3. Also, a settle time of 0.0775 seconds was obtained with the developed model while that of the AC3 model is 0.2986 seconds confirming, therefore, the superiority of the developed model over the AC3 model which, hitherto, served as a reference standard.

  16. The effects of variable speed and drive train component efficiencies on wind turbine energy capture

    Energy Technology Data Exchange (ETDEWEB)

    Fingersh, L.J.; Robinson, M.C.

    1998-05-01

    A wind turbine rotor achieves optimal aerodynamic efficiency at a single tip-speed ratio (TSR). To maintain that optimal TSR and maximize energy capture in the stochastic wind environment, it is necessary to employ variable-speed operation. Conventional constant-speed wind turbines have, in the past, been converted into variable-speed turbines by attaching power electronics to the conventional induction generator and gearbox drive train. Such turbines have shown marginal, if any, improvement in energy capture over their constant-speed counterparts. These discrepancies have been shown to be the result of drive train components that are not optimized for variable-speed operation. Traditional drive trains and power electronic converters are designed to achieve maximum efficiency at full load and speed. However, the main energy producing winds operate the turbine at light load for long periods of time. Because of this, significant losses to efficiency occur. This investigation employs a quasi-static model to demonstrate the dramatic effect that component efficiency curves can have on overall annual energy capture.

  17. Effects of Pay-As-You-Drive vehicle insurance on young drivers' speed choice : Results of a Dutch field experiment

    NARCIS (Netherlands)

    Bolderdijk, J.W.; Knockaert, J.; Steg, L.; Verhoef, E.T.

    2011-01-01

    Speeding is an important cause for young drivers' involvement in traffic accidents. A reduction in driving speeds of this group could result in fewer accidents. One way of reducing driving speed is offering explicit financial incentives. In collaboration with five Dutch car insurance companies, we t

  18. Two wheel speed robust sliding mode control for electric vehicle drive

    Directory of Open Access Journals (Sweden)

    Abdelfatah Nasri

    2008-01-01

    Full Text Available Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels.

  19. High Performance Variable Speed Drive System and Generating System with Doubly Fed Machines

    Science.gov (United States)

    Tang, Yifan

    Doubly fed machines are another alternative for variable speed drive systems. The doubly fed machines, including doubly fed induction machine, self-cascaded induction machine and doubly excited brushless reluctance machine, have several attractive advantages for variable speed drive applications, the most important one being the significant cost reduction with a reduced power converter rating. With a better understanding, improved machine design, flexible power converters and innovated controllers, the doubly fed machines could favorably compete for many applications, which may also include variable speed power generations. The goal of this research is to enhance the attractiveness of the doubly fed machines for both variable speed drive and variable speed generator applications. Recognizing that wind power is one of the favorable clean, renewable energy sources that can contribute to the solution to the energy and environment dilemma, a novel variable-speed constant-frequency wind power generating system is proposed. By variable speed operation, energy capturing capability of the wind turbine is improved. The improvement can be further enhanced by effectively utilizing the doubly excited brushless reluctance machine in slip power recovery configuration. For the doubly fed machines, a stator flux two -axis dynamic model is established, based on which a flexible active and reactive power control strategy can be developed. High performance operation of the drive and generating systems is obtained through advanced control methods, including stator field orientation control, fuzzy logic control and adaptive fuzzy control. System studies are pursued through unified modeling, computer simulation, stability analysis and power flow analysis of the complete drive system or generating system with the machine, the converter and the control. Laboratory implementations and tested results with a digital signal processor system are also presented.

  20. Simplified Fuzzy Control for Flux-Weakening Speed Control of IPMSM Drive

    Directory of Open Access Journals (Sweden)

    M. J. Hossain

    2011-01-01

    Full Text Available This paper presents a simplified fuzzy logic-based speed control scheme of an interior permanent magnet synchronous motor (IPMSM above the base speed using a flux-weakening method. In this work, nonlinear expressions of d-axis and q-axis currents of the IPMSM have been derived and subsequently incorporated in the control algorithm for the practical purpose in order to implement fuzzy-based flux-weakening strategy to operate the motor above the base speed. The fundamentals of fuzzy logic algorithms as related to motor control applications are also illustrated. A simplified fuzzy speed controller (FLC for the IPMSM drive has been designed and incorporated in the drive system to maintain high performance standards. The efficacy of the proposed simplified FLC-based IPMSM drive is verified by simulation at various dynamic operating conditions. The simplified FLC is found to be robust and efficient. Laboratory test results of proportional integral (PI controller-based IPMSM drive have been compared with the simulated results of fuzzy controller-based flux-weakening IPMSM drive system.

  1. Design and static performance of high speed machining centre with "direct drive"

    Institute of Scientific and Technical Information of China (English)

    Shuhong XIAO; Yulian CHEN; Guangyuan ZHENG

    2009-01-01

    "Direct drive" is an ideal method for speeding machine tools. In the structure of a CNC machining centre with "direct drive", the linear motor's primary and secondary parts are assembled into the worktable and machine bed respectively to directly drive the worktable. The built-in rotary motor is assembled in the spindle to realize the main transmission system of the machine tool "direct drive". All mechanical transmission elements in machine tools are eliminated. High speed, efficiency, and accuracy are easily obtained. However, in this type of "direct drive" machining centre, the magnetic attraction force between the primary and the secondary linear motors and the dynamic impact at acceleration and deceleration are directly imposed on the machine tool, and influence the performance of the machining centre. This paper analyzes the special demands of "direct drive" on the machine centre, and introduces a new structure of the machining tool. The worktable and machine bed are optimized to meet the special demands of "direct drive". Static performance simulation on the machining centre is done to reveal an ideal result.

  2. Senserless Speed and Position of Direct Field Orientation Control Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Mohammed Khalil Hussain

    2012-01-01

    Full Text Available Direct field-orientation Control (DFOC of induction motor drives without mechanical speed sensors at the motor shaft has the attractions of low cost and high reliability. To replace the sensor, information on the rotor speed and position are extracted from measured stator currents and from voltages at motor terminals. In this paper presents direct field-orientation control (DFOC with two type of kalman filter (complete order and reduced order extended kalman filter to estimate flux, speed, torque and position. Simulated results show how good performance for reduced order extended kalman filter over that of complete order extended kalman filter in tracking performance and reduced time of state estimation.

  3. Novel Position and Speed Estimator for PM Single Phase Brushless D.C. Motor Drives

    DEFF Research Database (Denmark)

    Lepure, Liviu I.; Andreescu, Gheorghe-Daniel; Iles, Doris;

    2010-01-01

    A novel position and speed estimator for single phase permanent magnet brushless d.c. (PMBLDC) motor drives, based on flux integration and prior knowledge of ΨPM (θ) is proposed here and an adequate correction algorithm is adopted in order to increase the robustness to noise and to reduce...... the sensitivity to accuracy of flux linkage estimation. A speed and current close loop control is employed based on the Hall signal and the motor is controlled at different speeds in order to validate the proposed estimation algorithm with satisfying results. The position correction effect is analyzed...

  4. Speed regulated drives save energy and operating cost; Drehzahlvariable Antriebe senken Energie- und Betriebskosten

    Energy Technology Data Exchange (ETDEWEB)

    Possberg, Norbert

    2009-12-15

    The cement factory of the Lafarge group at Hope, United Kingdom, retrofitted the last two drive units of the production chain by an electronic speed regulation. By utilization of frequency converters in the cooler ventilation sector the total energy consumption lowered to more than 15 %. (orig./GL)

  5. Concepts for Multi-Speed Rotorcraft Drive System - Status of Design and Testing at NASA GRC

    Science.gov (United States)

    Stevens, Mark A.; Lewicki, David G.; Handschuh, Robert F.

    2015-01-01

    In several studies and on-going developments for advanced rotorcraft, the need for variable/multi-speed capable rotors has been raised. Speed changes of up to 50 percent have been proposed for future rotorcraft to improve vehicle performance. A rotor speed change during operation not only requires a rotor that can perform effectively over the operating speed/load range, but also requires a propulsion system possessing these same capabilities. A study was completed investigating possible drive system arrangements that can accommodate up to a 50 percent speed change. Key drivers were identified from which simplicity and weight were judged as central. This paper presents the current status of two gear train concepts coupled with the first of two clutch types developed and tested thus far with focus on design lessons learned and areas requiring development. Also, a third concept is presented, a dual input planetary differential as leveraged from a simple planetary with fixed carrier.

  6. Comparative Study of Fuzzy Logic Based Speed Control of Multilevel Inverter fed Brushless DC Motor Drive

    Directory of Open Access Journals (Sweden)

    Pritha Agrawal

    2014-02-01

    Full Text Available This paper presents a comparative analysis of speed control of brushless DC motor (BLDC drive fed with conventional two-level, three and five level diode clamped multilevel inverter (DC-MLI. The performance of the drive system is successfully evaluated using Fuzzy Logic (FL based speed controller. The control structure of the proposed drive system is described. The speed and torque characteristic of conventional two-level inverter is compared with the three and five-level multilevel inverter (MLI for various operating conditions. The three and five level diode clamped multilevel inverters are simulated using IGBT’s and the mathematical model of BLDC motor has been developed in MATLAB/SIMULINK environment. The simulation results show that the Fuzzy based speed controller eliminate torque ripples and provides fast speed response. The developed Fuzzy Logic model has the ability to learn instantaneously and adapt its own controller parameters based on disturbances with minimum steady state error, overshoot and rise time of the output voltage.

  7. Closed Loop Speed Control of a BLDC Motor Drive Using Adaptive Fuzzy Tuned PI Controller

    Directory of Open Access Journals (Sweden)

    Sri Latha Eti

    2014-11-01

    Full Text Available Brushless DC Motors are widely used for many industrial applications because of their high efficiency, high torque and low volume. This paper proposed an improved Adaptive Fuzzy PI controller to control the speed of BLDC motor. This paper provides an overview of different tuning methods of PID Controller applied to control the speed of the transfer function model of the BLDC motor drive and then to the mathematical model of the BLDC motor drive. It is difficult to tune the parameters and get satisfied control characteristics by using normal conventional PI controller. The experimental results verify that Adaptive Fuzzy PI controller has better control performance than the conventional PI controller. The modeling, control and simulation of the BLDC motor have been done using the MATLAB/SIMULINK software. Also, the dynamic characteristics of the BLDC motor (i.e. speed and torque as well as currents and voltages of the inverter components are observed by using the developed model.

  8. The design and development of a constant-speed solar array drive

    Science.gov (United States)

    Jones, H. M.; Roger, N.

    1985-01-01

    The design and development of a constant-speed solar array drive system for use in high power communications satellites is described. The relationship between continuity of motion in the solar array drive and spacecraft attitude disturbance is investigated. The selection of the system design based on the design requirements including spacecraft disturbance is discussed. The system comprises two main parts: the drive mechanism including small angle stepper motor and reduction gearing and the control electronics including ministepping drive circuits, such that a very small output step size is achieved. Factors contributing to discontinuities in motion are identified and discussed. Test methods for measurement of very small amplitudes of discontinuity at low rotational rates are described to assist in the testing of similar mechanisms.

  9. Modelling and Simulation of Variable Speed Thruster Drives with Full-Scale Verification

    Directory of Open Access Journals (Sweden)

    Jan F. Hansen

    2001-10-01

    Full Text Available In this paper considerations about modelling and simulation of variable speed thruster drives are made with comparison to full scale measurements from Varg FPSO. For special purpose vessels with electric propulsion operating in DP (Dynamic Positioning mode the thruster drives are essential for the vessel operation. Different model strategies of thruster drives are discussed. An advanced thruster drive model with a dynamic motor model and field vector control principle is shown. Simulations are performed with both the advanced model and a simplified model. These are compared with full-scale measurements from Varg FPSO. The simulation results correspond well with the measurements, for both the simplified model and the advanced model.

  10. Field Oriented Control for Rotor Position Estimation of IPM Drives over a Wide Speed Range

    Directory of Open Access Journals (Sweden)

    Ekhlas Kadhum

    2013-01-01

    Full Text Available Field oriented control strategy of Interior Permanent Magnet IPM Synchronous Motor drives over a wide speed range applications is presented. Rotor position estimation using model reference adaptive system method for IPM Drive without using a mechanical sensor is illustrated considering the effects of cross-saturation between the d and q axes. The cross saturation between d and q axes has been calculated by finite-element analysis. The inductance measurement regards the cross saturation which is used to obtain the suitable id - characteristics in base and flux weakening regions. The simulation results show that rotor position estimation error accuracy was improved. Various dynamic conditions have been investigated

  11. Investigation of Road Enviroment Effects on Choice of Urban and Interurban Driving Speed

    Directory of Open Access Journals (Sweden)

    Ádám Török

    2011-03-01

    Full Text Available Human factor plays the most determinant role in traffic accidents. Speeding is a dominant cause of accidents in road transport. However, in order to improve safety, this is not the only element of the road transport system that should be considered. The road and/ or environment influence that behaviour as well, but they can be modified more quickly than drivers’ behaviour, and their effect can also be demonstrated. This paper describes the effect of road environment on chosen driving speed. Decisions of drivers are influenced by environmental impacts. Some of these impacts are planned, deliberate stimuli, being a part of the telematic systems of traffic control. In this paper the measure of road vehicles speed was analyzed on certain road urban and interurban sections which can be characterized by different design speed and construction parameters. Methods of mathematical statistics have been used to prove the hypothesis; the driving speed chosen by the driver depends heavily on the characteristics of urban and interurban road section. The aim of the author is to prove this hypothesis and the difference between urban and interurban decision environment.

  12. Modelling and control algorithms of the cross conveyors line with multiengine variable speed drives

    Science.gov (United States)

    Cheremushkina, M. S.; Baburin, S. V.

    2017-02-01

    The paper deals with the actual problem of developing the control algorithm that meets the technical requirements of the mine belt conveyors, and enables energy and resource savings taking into account a random sort of traffic. The most effective method of solution of these tasks is the construction of control systems with the use of variable speed drives for asynchronous motors. The authors designed the mathematical model of the system ‘variable speed multiengine drive – conveyor – control system of conveyors’ that takes into account the dynamic processes occurring in the elements of the transport system, provides an assessment of the energy efficiency of application the developed algorithms, which allows one to reduce the dynamic overload in the belt to 15-20%.

  13. Performance Indices Based Optimal Tunning Criterion for Speed Control of DC Drives Using GA

    Directory of Open Access Journals (Sweden)

    Deepti Singh

    2014-12-01

    Full Text Available This paper presents a framework to carry out a simulation to tune the speed controller gains for known input of DC drive system. The objective is to find the optimal controller gains (proportional and integral in a closed loop system. Various performance indices have been considered as optimal criterion in this work. The optimal gain values have been obtained by conventional and Genetic Algorithm (GA based optimization methods. The study has been conducted on a simulink model of three phase converter controlled direct current (DC drive with current and speed control strategy. The results show that the GA based tunning provided better solutions as compared to conventional optimization methods based tunning.

  14. Variable Speed Wind Turbine Based on Multiple Generators Drive-Train Configuration

    DEFF Research Database (Denmark)

    Deng, Fujin; Chen, Zhe

    2010-01-01

    A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine. A cascaded multilevel converter interface based on the MPMSGs is developed to synthesize a desired high ac sinusoidal...... output voltage, which could be directly connected to the grids. What is more, such arrangement has been made so that the output ac voltage having a selected phase angle difference among the stator windings of multiple generators. A phase angle shift strategy is proposed in this paper, which effectively...... reduce the fluctuation of the electromagnetic torque sum and results in a good performance for the MPMSGs structure. The simulation study is conducted using PSCAD/EMTDC, and the results verify the feasibility of this variable speed wind turbine based on multiple generators drive-train configuration....

  15. Nonlinear Speed Control of Switched Reluctance Motor Drives Taking into Account Mutual Inductance

    Directory of Open Access Journals (Sweden)

    M. Alrifai

    2008-01-01

    Full Text Available A speed control algorithm is proposed for variable speed switched reluctance motor (SRM drives taking into account the effects of mutual inductances. The control scheme adopts two-phase excitation; exciting two adjacent phases can overcome the problems associated with single-phase excitation such as large torque ripple, increased acoustic noise, and rotor shaft fatigues. The effects of mutual coupling between two adjacent phases and their contribution to the generated electromagnetic torque are considered in the design of the proposed control scheme for the motor. The proposed controller guarantees the convergence of the currents and the rotor speed of the motor to their desired values. Simulation results are given to illustrate the developed theory; the simulation studies show that the proposed controller works well. Moreover, the simulation results indicate that the proposed controller is robust to changes in the parameters of the motor and to changes in the load torque.

  16. Optimal Predictive Control for Path Following of a Full Drive-by-Wire Vehicle at Varying Speeds

    Science.gov (United States)

    SONG, Pan; GAO, Bolin; XIE, Shugang; FANG, Rui

    2017-03-01

    The current research of the global chassis control problem for the full drive-by-wire vehicle focuses on the control allocation (CA) of the four-wheel-distributed traction/braking/steering systems. However, the path following performance and the handling stability of the vehicle can be enhanced a step further by automatically adjusting the vehicle speed to the optimal value. The optimal solution for the combined longitudinal and lateral motion control (MC) problem is given. First, a new variable step-size spatial transformation method is proposed and utilized in the prediction model to derive the dynamics of the vehicle with respect to the road, such that the tracking errors can be explicitly obtained over the prediction horizon at varying speeds. Second, a nonlinear model predictive control (NMPC) algorithm is introduced to handle the nonlinear coupling between any two directions of the vehicular planar motion and computes the sequence of the optimal motion states for following the desired path. Third, a hierarchical control structure is proposed to separate the motion controller into a NMPC based path planner and a terminal sliding mode control (TSMC) based path follower. As revealed through off-line simulations, the hierarchical methodology brings nearly 1700% improvement in computational efficiency without loss of control performance. Finally, the control algorithm is verified through a hardware in-the-loop simulation system. Double-lane-change (DLC) test results show that by using the optimal predictive controller, the root-mean-square (RMS) values of the lateral deviations and the orientation errors can be reduced by 41% and 30%, respectively, comparing to those by the optimal preview acceleration (OPA) driver model with the non-preview speed-tracking method. Additionally, the average vehicle speed is increased by 0.26 km/h with the peak sideslip angle suppressed to 1.9°. This research proposes a novel motion controller, which provides the full drive

  17. Balancing rotor speed regulation and drive train loads of floating wind turbines

    Science.gov (United States)

    Fischer, Boris; Loepelmann, Peter

    2016-09-01

    The interaction of the blade pitch controller with structural motion is particularly important for wind turbines mounted on floating platforms. A controls-based approach to overcome the related technical challenges is to feed back the nacelle's motion to the demanded generator torque. This work aims to further improve this approach by feeding back only a narrow fraction of the available frequency range. Simulations show that, in doing so, unrealistically high torque magnitudes are avoided, and better a trade-off between rotor speed regulation and drive train loads is achieved.

  18. Commissioning of 30 kVA variable-speed, direct-drive wind power plant

    Science.gov (United States)

    Yildirim, Deniz

    Most wind turbines in service today employ induction generators together with a step-up mechanical gear so that the operational speed is close to the synchronous speed of two or four-pole generators. Because of the torque-speed characteristic of induction generators, the range of speed change is rather small; therefore, the operational speed can be considered to be nearly constant. Mechanical gears are subject to wear and tear, reduce reliability of the drive train and add to its weight. The maximum power that can be extracted from wind varies with its speed. Therefore, a direct-drive system, where a wind turbine is directly coupled to the generator shaft, is desirable along with a variable-speed operation. The variable-speed, direct-drive train described in this thesis consists of a lowspeed, permanent-magnet generator (60 to 120rpm), a resonant rectifier and a pulsewidth-modulated inverter. It supplies 30 kVA/20kW apparent/real power to the utility system at leading and unity power factors for a given DC link voltage. The amplitude and phase (leading, unity) of the AC current delivered to the utility system are controllable and the voltage/current wave forms at the point of common coupling satisfy standard IEEE-519. The overall efficiency of the drive train is about 83% (excluding the generator), whereby the rectifier has an efficiency of 86% and the inverter efficiency is around 95%. Using two different approaches (computer-aided and three-voltmeter methods), the losses of inductors are measured for the frequency range of 0 to 6 kHz. Measurement errors of both methods are less than 10% when measuring a few watts. The AC resistance increase of a Litz-wire inductor without a core is smallest among all of the inductors being tested. Stranding of individual (uninsulated) wires to obtain a flexible cable results in more losses than using a solid cable having the same cross-sectional area as that of a stranded cable. Nonsinusoidal voltages and currents in a power

  19. Robust Controller Design for Speed Control of an Indirect Field Oriented Induction Machine Drive

    Directory of Open Access Journals (Sweden)

    A. MILOUDI

    2005-01-01

    Full Text Available The use of PI controllers for speed control of induction machine drives is characterized by an overshoot during tracking mode and a poor load disturbance rejection. This is mainly caused by the fact that the complexity of the system does not allow the gains of the PI controller to exceed a certain low value. At starting mode the high value of the error is amplified across the PI controller provoking high variations in the command torque. If the gains of the controller exceed a certain value, the variations in the command torque become too high and will destabilize the system.To overcome this problem we propose the use of a limiter ahead of the PI controller. This limiter causes the speed error to be maintained within the saturation limits provoking, when appropriately chosen, smooth variations in the command torque even when the PI controller gains are very high.In this paper, a new approach to control the speed of an indirect field oriented induction machine drive using a classical PI controller is proposed. Its simulated input – output non linear relationship is then learned off – line using a feed – forward linear network with one hidden layer.The simulation of the system using either the modified PI controller or the learned neural network controller shows promising results. The motor reaches the reference speed rapidly and without overshoot, step commands are tracked with almost zero steady state error and no overshoot, load disturbances are rapidly rejected and variations of some of the motor parameters are fairly well dealt with.

  20. Variable-Speed Induction Motor Drives for Aircraft Environmental Control Compressors

    Science.gov (United States)

    Mildice, J. W.; Hansen, I. G.; Schreiner, K. E.; Roth, M. E.

    1996-01-01

    New, more-efficient designs for aircraft jet engines are not capable of supplying the large quantities of bleed air necessary to provide pressurization and air conditioning for the environmental control systems (ECS) of the next generation of large passenger aircraft. System analysis and engineering have determined that electrically-driven ECS can help to maintain the improved fuel efficiencies; and electronic controllers and induction motors are now being developed in a NASA/NPD SBIR Program to drive both types of ECS compressors. Previous variable-speed induction motor/controller system developments and publications have primarily focused on field-oriented control, with large transient reserve power, for maximum acceleration and optimum response in actuator and robotics systems. The application area addressed herein is characterized by slowly-changing inputs and outputs, small reserve power capability for acceleration, and optimization for maximum efficiency. This paper therefore focuses on the differences between this case and the optimum response case, and shows the development of this new motor/controller approach. It starts with the creation of a new set of controller requirements. In response to those requirements, new control algorithms are being developed and implemented in an embedded computer, which is integrated into the motor controller closed loop. Buffered logic outputs are used to drive the power switches in a resonant-technology, power processor/motor-controller, at switching/resonant frequencies high enough to support efficient high-frequency induction motor operation at speeds up to 50,000-RPA

  1. Distinct mechanisms mediate speed-accuracy adjustments in cortico-subthalamic networks

    Science.gov (United States)

    Herz, Damian M; Tan, Huiling; Brittain, John-Stuart; Fischer, Petra; Cheeran, Binith; Green, Alexander L; FitzGerald, James; Aziz, Tipu Z; Ashkan, Keyoumars; Little, Simon; Foltynie, Thomas; Limousin, Patricia; Zrinzo, Ludvic; Bogacz, Rafal; Brown, Peter

    2017-01-01

    Optimal decision-making requires balancing fast but error-prone and more accurate but slower decisions through adjustments of decision thresholds. Here, we demonstrate two distinct correlates of such speed-accuracy adjustments by recording subthalamic nucleus (STN) activity and electroencephalography in 11 Parkinson’s disease patients during a perceptual decision-making task; STN low-frequency oscillatory (LFO) activity (2–8 Hz), coupled to activity at prefrontal electrode Fz, and STN beta activity (13–30 Hz) coupled to electrodes C3/C4 close to motor cortex. These two correlates differed not only in their cortical topography and spectral characteristics but also in the relative timing of recruitment and in their precise relationship with decision thresholds. Increases of STN LFO power preceding the response predicted increased thresholds only after accuracy instructions, while cue-induced reductions of STN beta power decreased thresholds irrespective of instructions. These findings indicate that distinct neural mechanisms determine whether a decision will be made in haste or with caution. DOI: http://dx.doi.org/10.7554/eLife.21481.001 PMID:28137358

  2. Wavelet transform with fuzzy tuning based indirect field oriented speed control of three-phase induction motor drive

    DEFF Research Database (Denmark)

    Sanjeevikumar, P.; Daya, J.L. Febin; Wheeler, Patrick

    2015-01-01

    This manuscript presents the details about the novel controller using wavelet transform and fuzzy logic tuning for speed control of an induction motor drive. The conventional proportional-integral (PI) speed controller in an indirect vector control of induction motor drive has been replaced by th...... controller along with an induction motor drive incorporating the proposed controller has been developed in numerical simulation software using Matlab/Simulink environment and a set of results are provided within this paper in comparison to the conventional controller scheme....

  3. A low-power high-speed driving circuit for spatial light modulators

    Science.gov (United States)

    Minghao, Zhu; Congyi, Zhu; Wenjiang, Li; Yaohui, Zhang

    2012-02-01

    This paper describes the design and test of a novel custom driving circuit for multi-quantum-well (MQW) spatial light modulators (SLMs). Unlike previous solutions, we integrated all blocks in one chip to synchronize the control logic circuit and the driving circuits. Single-slope digital-to-analog converters (DACs) inside each pixel are not adopted because it is difficult to eliminate capacitor mismatch. 64 column-shared 8-bit resistor-string DACs are utilized to provide programmable output voltages from 0.5 to 3.8 V. They are located on the top of 64 × 64 driving pixels tightly to match each other with several dummies. Each DAC performs its conversion in 280 ns and draws 80 μA. For a high speed data transfer rate, the system adopts a 2-stage shift register that operates at 50 MHz and the modulating rate achieves 50 K frames/s while dissipating 302 mW from a 5-V supply. The die is fabricated in a 0.35 μm CMOS process and its area is 5.5 × 7 mm2.

  4. Novel Observer Scheme of Fuzzy-MRAS Sensorless Speed Control of Induction Motor Drive

    Science.gov (United States)

    Chekroun, S.; Zerikat, M.; Mechernene, A.; Benharir, N.

    2017-01-01

    This paper presents a novel approach Fuzzy-MRAS conception for robust accurate tracking of induction motor drive operating in a high-performance drives environment. Of the different methods for sensorless control of induction motor drive the model reference adaptive system (MRAS) finds lot of attention due to its good performance. The analysis of the sensorless vector control system using MRAS is presented and the resistance parameters variations and speed observer using new Fuzzy Self-Tuning adaptive IP Controller is proposed. In fact, fuzzy logic is reminiscent of human thinking processes and natural language enabling decisions to be made based on vague information. The present approach helps to achieve a good dynamic response, disturbance rejection and low to plant parameter variations of the induction motor. In order to verify the performances of the proposed observer and control algorithms and to test behaviour of the controlled system, numerical simulation is achieved. Simulation results are presented and discussed to shown the validity and the performance of the proposed observer.

  5. A low-power high-speed driving circuit for spatial light modulators

    Institute of Scientific and Technical Information of China (English)

    朱明皓; 朱从义; 李文江; 张耀辉

    2012-01-01

    This paper describes the design and test of a novel custom driving circuit for multi-quantum-well (MQW) spatial light modulators (SLMs).Unlike previous solutions,we integrated all blocks in one chip to synchronize the control logic circuit and the driving circuits.Single-slope digital-to-analog converters (DACs) inside each pixel are not adopted because it is difficult to eliminate capacitor mismatch.64 column-shared 8-bit resistorstring DACs are utilized to provide programmable output voltages from 0.5 to 3.8 V.They are located on the top of 64 × 64 driving pixels tightly to match each other with several dummies.Each DAC performs its conversion in 280 ns and draws 80 μA.For a high speed data transfer rate,the system adopts a 2-stage shift register that operates at 50 MHz and the modulating rate achieves 50 K frames/s while dissipating 302 mW from a 5-V supply.The die is fabricated in a 0.35μm CMOS process and its area is 5.5 × 7 mm2.

  6. Brushless DC Motor Drive during Speed Regulation with Artificial Neural Network Controller

    Directory of Open Access Journals (Sweden)

    Sakshi Solanki

    2016-06-01

    Full Text Available Brushless DC motor, at this moment is extensively used being many industrial functions due to the different features like high efficiency and dynamic response and high speed range. This paper is proposing a technology named as Artificial Neural Network controller to control the speed of the brushless DC motor. Here the paper contributes an analysis of performance Artificial Neural Network controller. Because it is difficult to handle by the use of conventional PID controller as BLDC drive is a nonlinear. Through PID controller, the speed regulation of BLDC is not efficient and reliable as PID controller cannot operate the large data, results it gives different variation in BLDC motor control. The ANN easily trains the data of large amount by NN toolbox. As ANN controller has the strength to indulge characteristics of control and it is accessible to operate the huge amount of data as like human can store in a mind. The empirical results prove that an ANN controller can better control the act than the PID controller. The modelling, control and the simulation of the BLDCM get done by applying MATLAB/SIMULINK software kit.

  7. Combined Flux Observer With Signal Injection Enhancement for Wide Speed Range Sensorless Direct Torque Control of IPMSM Drives

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Andreescu, G.-D.; Pitic, C.I.;

    2008-01-01

    This paper proposes a motion-sensorless control system using direct torque control with space vector modulation for interior permanent magnet synchronous motor (IPMSM) drives, for wide speed range operation, including standstill. A novel stator flux observer with variable structure uses a combined...... voltage-current model with PI compensator for low-speed operations. As speed increases, the observer switches gradually to a PI compensated closed-loop voltage model, which is solely used at high speeds. High-frequency rotating-voltage injection with a single D-module bandpass vector filter and a phase...

  8. Type-2 fuzzy logic control based MRAS speed estimator for speed sensorless direct torque and flux control of an induction motor drive.

    Science.gov (United States)

    Ramesh, Tejavathu; Kumar Panda, Anup; Shiva Kumar, S

    2015-07-01

    In this research study, a model reference adaptive system (MRAS) speed estimator for speed sensorless direct torque and flux control (DTFC) of an induction motor drive (IMD) using two adaptation mechanism schemes are proposed to replace the conventional proportional integral controller (PIC). The first adaptation mechanism scheme is based on Type-1 fuzzy logic controller (T1FLC), which is used to achieve high performance sensorless drive in both transient as well as steady state conditions. However, the Type-1 fuzzy sets are certain and unable to work effectively when higher degree of uncertainties presents in the system which can be caused by sudden change in speed or different load disturbances, process noise etc. Therefore, a new Type-2 fuzzy logic controller (T2FLC) based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties and improves the performance and also robust to various load torque and sudden change in speed conditions, respectively. The detailed performances of various adaptation mechanism schemes are carried out in a MATLAB/Simulink environment with a speed sensor and speed sensorless modes of operation when an IMD is operating under different operating conditions, such as, no-load, load and sudden change in speed, respectively. To validate the different control approaches, the system also implemented on real-time system and adequate results are reported for its validation.

  9. An Algebraic Method of Synchronous Pulsewidth Modulation for Converters for Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede

    2002-01-01

    This paper describes the basic peculiarities of a new method of feedforward synchronous pulsewidth modulation (PWM) of the output voltage of converters, based on one-stage closed-form strategy of PWM with pure algebraic control dependencies. It is applied to voltage source inverters...... with a continuous scheme of conventional voltage space vector modulation and with two basic variants of symmetrical discontinuous PWM. Simulations give the behaviour of the proposed method and show the advantage of algebraic synchronous PWM compared with the typical asynchronous, for low indices of the frequency...

  10. Power-Quality-Oriented Optimization in Multiple Three-Phase Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Yang, Yongheng; Davari, Pooya; Blaabjerg, Frede;

    2016-01-01

    , low cost, and high reliability during operation. Yet, DRs and SCRs bring harmonic distortions in the mains and thus lowering the overall efficiency. Power quality standards/rules are thus released. For multiple ASD systems, certain harmonics of the total grid current can be mitigated by phase...

  11. Performance Evaluation of Electronic Inductor-Based Adjustable Speed Drives with Respect to Line Current Interharmonics

    DEFF Research Database (Denmark)

    Soltani, Hamid; Davari, Pooya; Zare, Firuz;

    2017-01-01

    attractive due to its improved harmonic performance compared to a conventional ASD. In this digest, the input currents of the EI-based ASD are investigated and compared with the conventional ASDs with respect to interharmonics, which is an emerging power quality topic. First, the main causes...

  12. An EMC Evaluation of the Use of Unshielded Motor Cables in AC Adjustable Speed Drive Applications

    DEFF Research Database (Denmark)

    Hanigovszki, Norbert; Poulsen, J.; Spiazzi, G.;

    2004-01-01

    -phase applications the occurrence of common-mode voltage is inherent due to asymmetrical output pulses. As a result, for electromagnetic compatibility (EMC) reasons, in most applications shielded cables are used between the inverter and the motor, implying high installation costs. The present paper discusses the use...... filter with DC link connection. It is concluded that, from an EMC point of view, unshielded cables can give very good performance provided that a common-mode (CM) output filter is used....

  13. Feedforward Synchronised PWM for Adjustable Speed AC Drives with Different Control Modes

    DEFF Research Database (Denmark)

    Oleschuk, Valentin; Blaabjerg, Frede; Jensen, Flemming Buus

    2002-01-01

    This paper presents a novel method of direct synchronised pulswidth modulation (PWM) for three-phase voltage source inverters, feeding induction motors with different control regimes. It is based on the universal algorithm with either simplified algebraic or accurate trigonometric control functions...

  14. Does movement planning follow Fitts' law? Scaling anticipatory postural adjustments with movement speed and accuracy.

    Science.gov (United States)

    Bertucco, M; Cesari, P

    2010-11-24

    We wanted to determine whether movement planning followed Fitts' law by investigating the relationship between movement planning and movement performance in experienced dancers executing a typical classical ballet step in which the big toe was pointed to targets at different distances and of different widths so as to obtain several indices of difficulty (ID). Movement time, velocity and variability at the target were the variables of movement performance kinematics; movement planning was evaluated by analysis of anticipatory postural adjustments (APAs) to assess their modulation at different IDs. Movement time and peak of velocity were found to scale with the ID only when individual movement distance across target widths was entered into the analysis. APA magnitude and duration both scaled according to movement parameters but not in the same way. APA magnitude scaled with movement velocity, while APA duration was sensitive to the amplitude-to-accuracy ratio following the ID for movements performed in the shortest time interval when on-line feedback control is probably not available. Here we show that timing of muscle activation acts as an independent central command that triggers fine-tuning for speed-accuracy trade-off.

  15. Environmentally friendly drive for gas compression applications: enhanced design of high-speed induction motors

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Karina Velloso; Pradurat, Jean Francois; Mercier, Jean Charles [Institut National Polytechncique, Lorrain (France). Converteam Motors Div.; Truchot, Patrick [Nancy Universite (France). Equipe de Recherche sur les Processus Innovatifs (ERPI)

    2008-07-01

    Taking into account the key issues faced by gas compressors users, this paper aims to help optimize the choice of the drive equipment as well as the driven equipment, in function of the cost of the whole installation life cycle. The design of the enhanced high-speed induction motor (MGV-Moteuer a Grande Vitesse) represents a technological breakthrough for the industry, it allows the direct coupling to the compressor, without using a gearbox making the system more efficient and reliable. From both micro and macro-economic viewpoints, the high-speed electric driver becomes a more efficient use of natural gas energy resources. This new technology associated with the electric option offers challenging and rewarding work to those responsible for the operation and maintenance of the compressor station. The electric option is not only conceptually viable but has a proven track record that justifies serious consideration as an alternative for reliably powering. Once an operator becomes comfortable with the prospects of motor-driven compression, the analysis of machine options requires only a few new approaches to fairly evaluate the alternatives. The application of this reasoning in projects using compression units is especially opportune, in view of the great variations of operational conditions and environmental issues. (author)

  16. SPEED CONTROL OF PMBLDC DRIVE WITH GATE CONTROL METHOD USING CONVENTIONAL AND FUZZY CONTROLLER

    Directory of Open Access Journals (Sweden)

    T.V.NARMADHA,

    2010-11-01

    Full Text Available The paper presents simulation results of fuzzy logic and conventional proportional integral controller for the sensorless speed control of permanent magnet brushless dc (PMBLDC motor using Gate control method. Although conventional PI controllers are widely used in the industry due to its simple control structure and ease of implementation, these controllers pose difficulties under the conditions of nonlinearity, load disturbances and parametric variations. Moreover PI controllers require precise linear mathematical models. In the paper, the performance of the permanent magnet brushless dc motor drive is examined with the aid of the fuzzy logic controller. The fuzzy logic controller shows improved performance compared to the conventional PI speed controller. The module of the Three Phase inverter system controlled Permanent magnet Brushless DC motor is simulated using PI and Fuzzy Logic Controller and implemented in closed loop model. . By simulation, the characteristics of the PMBLDCM system are investigated. THD analysis for the methods is presented. The simulation results indicate FLC has improved performance.

  17. Speed adjustment of blowers in refrigeration engineering. Exemplary applications; Verfahren der Drehzahlveraenderung von Ventilatoren in der Kaeltetechnik. Beispiel verschiedener Anwendungsfaelle

    Energy Technology Data Exchange (ETDEWEB)

    Albig, J. [Ziehl-Abegg AG, Kuenzelsau (Germany)

    2007-02-15

    Apart from the motor performance, also the investment cost of speed adjustment systems decide the economic efficiency of blowers. The blower performance itself is left out of account in this investigation. The most common control strategies are investigated, i.e. voltage control, frequence control, and EC technology. (orig.)

  18. 锅炉给粉变频调速系统%Varying Frequency Speed Adjustment System for Boiler Feeding Coal

    Institute of Scientific and Technical Information of China (English)

    张焕武

    2000-01-01

    This paper briefly introduces the design of varying frequency speed adjustment system for boiler feeding coal and simply introduces it's advantages.%简要介绍了锅炉给粉变频调速系统的设计,并概述了其优越性。

  19. Large output-power, low-speed permanent magnet synchronous motor designs for ship propulsion drive

    Energy Technology Data Exchange (ETDEWEB)

    Rosu, M.

    2001-07-01

    Over the last decade, serious development has taken place in electric motor technology, and its impact is being felt in the shipbuilding community. This development has brought about a new generation of compact, high efficiency electrical machines. High performance, lightweight permanent magnet motors and generators have been developed for a wide range of applications including vehicle propulsion, power generation, pump and compressor drives. These machines combine the advances in magnetic materials and electronic design to provide shipbuilders new options for weight, energy and cost reduction. Permanent magnet machines were built in many different configurations and power classes, ranging from a few hundred watts to multi-megawatts for ship propulsion. Permanent magnet motors and generators for marine use were constructed and tested, all of these machines providing the same outstanding torque and power density. The basic electromagnetic, thermal and mechanical design approaches were established and tested in small prototype machines, the development of larger machines constituting the engineering later in the design process. The goal of this research work is to find an optimum solution in terms of design and suitability of a low-speed and high-power permanent magnet motor for ship propulsion drive. In this work, the study-case analyses are limited to the electromagnetic part of the motor. Two types of radial flux permanent magnet synchronous motors are designed and optimised to meet the propulsion requirements. The first motor has the permanent magnets mounted on the surface of the rotor while the second motor has the permanent magnets mounted on the rotor surface and covered by laminated pole shoes. In their construction, high-energy NdFeB permanent magnets were chosen. These magnetic materials provide a sufficient airgap magnetic flux density with a low volume of material. Moreover, the NdFeB permanent magnets are endowed with high coercivity. As an immediate

  20. Test facility for advanced electric adjustable frequency drives and generators of typical industrial ratings. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    A test facility has been developed, for electric adjustable-speed motors and variable-speed generators, that is unique in US universities in terms of its range (5 to 300 hp currently with 0.1 to 1,000 hp final capability) and flexibility (standard NEMA frame and novel geometry machines can be accommodated). The basic facility was constructed with funding from the Electric Power Research Institute. The instrumentation obtained under this DOE grant has been integrated into the facility which was completed in Fall 1997. The facility has already provided useful studies for DOE, EPRI, as well as several West Coast industries and electric energy utilities.

  1. Practical Wide-speed-range Sensorless Control System for Permanent Magnet Reluctance Synchronous Motor Drives via Active Flux Model

    DEFF Research Database (Denmark)

    Ancuti, Mihaela Codruta; Tutelea, Lucian; Andreescu, Gheorghe-Daniel

    2014-01-01

    This article introduces a control strategy to obtain near-maximum available torque in a wide speed range with sensorless operation via the active flux concept for permanent magnet-reluctance synchronous motor drives. A new torque dq current reference calculator is proposed, with reference torque...... digital simulation results (1–6000 rpm) and experimental results (50–3000 rpm at low inverter available DC voltage of 12 Vdc instead of 48 Vdc) demonstrate the effectiveness of the proposed sensorless control strategy in a wide speed range, with stable and reliable operations up to a speed equal to eight...

  2. Speed Sensorless vector control of parallel-connected three-phase two-motor single-inverter drive system

    DEFF Research Database (Denmark)

    Gunabalan, Ramachandiran; Sanjeevikumar, Padmanaban; Blaabjerg, Frede

    2016-01-01

    This paper presents the characteristic behavior of direct vector control of two induction motors with sensorless speed feedback having the same rating parameters, paralleled combination, and supplied from a single current-controlled pulse-width-modulated voltage-source inverter drive. Natural...... to noise and parameter uncertainty. The gain matrix is absent in the natural observer. The rotor speed is estimated from the load torque, stator current, and rotor flux. Under symmetrical load conditions, the difference in speed between two induction motors is reduced by considering the motor parameters...

  3. Using Artificial Neural Networks for Energy Regulation Based Variable-speed Electrohydraulic Drive

    Institute of Scientific and Technical Information of China (English)

    XU Ming; JIN Bo; YU Yaxin; SHEN Haikuo; LI Wei

    2010-01-01

    In the energy regulation based varibable-speed electrohydraulic drive system, the supply energy and the demanded energy, which will affect the control performance greatly, are crucial. However, they are hard to be obtained via conventional methods for some reasons. This paper tries to a new route: the definitive numerical values of the supply energy and the demanded energy are not required, except for their relationship which is called energy state. A three-layer back propagation(BP) neural network was built up to act as an energy analysis unit to deduce the energy state. The neural network has three inputs: the reference displacement, the actual displacement of cylinder rod and the system flowrate supply. The output of the neural network is energy state. A Chebyshev type II filter was designed to calculate the cylinder speed for the estimation of system flowrate supply. The training and testing samples of neural network were collected by the system accurate simulation model. After off-line training, the neural network was tested by the testing data. And the testing result demonstrates that the designed neural network was successful. Then, the neural network acts as the energy analysis unit in real-time experiments of cylinder position control, where it works efficiently under square-wave and sine-wave reference displacement. The experimental results validate its feasibility and adaptability. Only a position sensor and some pressure sensors, which are cheap and have quick dynamic response, are necessary for the system control. And the neural network plays the role of identifying the energy state.

  4. Gear Design Effects on the Performance of High Speed Helical Gear Trains as Used in Aerospace Drive Systems

    Science.gov (United States)

    Handschuh, R.; Kilmain, C.; Ehinger, R.; Sinusas, E.

    2013-01-01

    The performance of high-speed helical gear trains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction / torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High Speed Helical Gear Train Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160 to 250 degF) and lubricating jet pressure (60 to 80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears. The empirical data resulting from this study will be useful to the design of future helical gear train systems anticipated for next generation rotorcraft drive systems.

  5. DEVELOPMENT OF OPTIMUM SPEED DIAGRAMS FOR SMALL MOVEMENT OF AN ACTUATING DEVICE OF AС ELECTRIC DRIVE-WITH ELASTIC SHAFTING

    Directory of Open Access Journals (Sweden)

    Dobrobaba Y. P.

    2013-10-01

    Full Text Available In this article we describe the optimum speed diagram of moving actuating device of АС electric drive with elastic shafting. Parameters, conditions of existence and dependence of the duration of the cycle from the angle of rotation of actuating device are defined as well

  6. Gait Parameter Adjustments for Walking on a Treadmill at Preferred, Slower, and Faster Speeds in Older Adults with Down Syndrome

    Directory of Open Access Journals (Sweden)

    Beth A. Smith

    2012-01-01

    Full Text Available The combined effects of ligamentous laxity, hypotonia, and decrements associated with aging lead to stability-enhancing foot placement adaptations during routine overground walking at a younger age in adults with Down syndrome (DS compared to their peers with typical development (TD. Our purpose here was to examine real-time adaptations in older adults with DS by testing their responses to walking on a treadmill at their preferred speed and at speeds slower and faster than preferred. We found that older adults with DS were able to adapt their gait to slower and faster than preferred treadmill speeds; however, they maintained their stability-enhancing foot placements at all speeds compared to their peers with TD. All adults adapted their gait patterns similarly in response to faster and slower than preferred treadmill-walking speeds. They increased stride frequency and stride length, maintained step width, and decreased percent stance as treadmill speed increased. Older adults with DS, however, adjusted their stride frequencies significantly less than their peers with TD. Our results show that older adults with DS have the capacity to adapt their gait parameters in response to different walking speeds while also supporting the need for intervention to increase gait stability.

  7. Fast response Antiwindup PI speed controller of Brushless DC motor drive: Modeling, simulation and implementation on DSP

    Directory of Open Access Journals (Sweden)

    Mohd Tariq

    2016-05-01

    Full Text Available Most of the Brushless DC (BLDC motors drive adopts proportional, integral and derivative (PID controller and pulse width modulation (PWM scheme for speed control. Hence, BLDC motor drive has strong saturation characteristics. The saturation results in a typical windup phenomenon. The paper presents an Antiwindup drive for BLDC motor. An Antiwindup controller (AWC has been used in the paper. AWC has been modeled in MATLAB/Simulink and comparison has been done between conventional PI controller and AWC at different starting loads. Dynamic characteristics of the BLDC motor drive have been examined and results are presented and discussed in detail in this paper. Details of DSP based experimental validation of the simulated results are also presented here.

  8. Implementation of a sliding-mode-based position sensorless drive for high-speed micro permanent-magnet synchronous motors.

    Science.gov (United States)

    Chi, Wen-Chun; Cheng, Ming-Yang

    2014-03-01

    Due to issues such as limited space, it is difficult if it is not impossible to employ a position sensor in the drive control of high-speed micro PMSMs. In order to alleviate this problem, this paper analyzes and implements a simple and robust position sensorless field-oriented control method of high-speed micro PMSMs based on the sliding-mode observer. In particular, the angular position and velocity of the rotor of the high-speed micro PMSM are estimated using the sliding-mode observer. This observer is able to accurately estimate rotor position in the low speed region and guarantee fast convergence of the observer in the high speed region. The proposed position sensorless control method is suitable for electric dental handpiece motor drives where a wide speed range operation is essential. The proposed sensorless FOC method is implemented using a cost-effective 16-bit microcontroller and tested in a prototype electric dental handpiece motor. Several experiments are performed to verify the effectiveness of the proposed method.

  9. Evidence that attitude accessibility augments the relationship between speeding attitudes and speeding behavior: a test of the MODE model in the context of driving.

    Science.gov (United States)

    Elliott, Mark A; Lee, Emme; Robertson, Jamie S; Innes, Rhona

    2015-01-01

    According to the MODE model of attitude-to-behavior processes, attitude accessibility augments attitude-behavior correspondence, reflecting an automatic influence of attitudes on behavior. We therefore tested whether attitude accessibility moderates the attitude-behavior relationship in a context that is governed by characteristically automatic behavior, namely driving. In study 1 (correlational design), participants (N=130) completed online questionnaire measures of the valences and accessibilities of their attitudes towards speeding. Two weeks later, online questionnaire measures of subsequent speeding behavior were obtained. Attitude valence was a significantly better predictor of behavior at high (mean+1SD) versus low (mean-1SD) levels of attitude accessibility. In study 2 (experimental design), attitude accessibility was manipulated with a repeated attitude expression task. Immediately after the manipulation, participants (N=122) completed online questionnaire measures of attitude valence and accessibility, and two weeks later, subsequent speeding behavior. Increased attitude accessibility in the experimental (versus control) condition generated an increase in attitude-behavior correspondence. The findings are consistent with the MODE model's proposition that attitudes can exert an automatic influence on behavior. Interventions to reduce speeding could usefully increase the accessibility of anti-speeding attitudes and reduce the accessibility of pro-speeding attitudes.

  10. Fault Detection in Gear Drives with Non-Stationary Rotational Speed-Part i: the Time-Frequency Approach

    Science.gov (United States)

    Meltzer, G.; Ivanov, Yu Ye

    2003-09-01

    This paper deals with the recognition of faults in toothing during non-stationary start-up and run-down of gear drives. In the first part, this task will be solved by means of the time-frequency analysis. As a practical case study, we investigated a planetary gear for passenger cars. New exponental smoothing kernels which respect to the known-in-advance angular acceleration of gear drive were created. These kernels must be adapted in the case of an in-advance-unknown course of rotational speed.

  11. Meiotic drive and sex determination: molecular and cytological mechanisms of sex ratio adjustment in birds

    OpenAIRE

    2007-01-01

    Differences in relative fitness of male and female offspring across ecological and social environments should favour the evolution of sex-determining mechanisms that enable adjustment of brood sex ratio to the context of breeding. Despite the expectation that genetic sex determination should not produce consistent bias in primary sex ratios, extensive and adaptive modifications of offspring sex ratio in relation to social and physiological conditions during reproduction are often documented. ...

  12. Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit.

    Science.gov (United States)

    Sato, Katsufumi; Ponganis, Paul J; Habara, Yoshiaki; Naito, Yasuhiko

    2005-07-01

    Emperor penguins leap from the water onto the sea ice. Their ability to reach above-water height depends critically on initial vertical speed of their leaping, assuming that the kinetic energy is converted to gravitational potential energy. We deliberately changed the above-water heights of ice hole exits, in order to examine whether penguins adjusted swim speed in accordance with the above-water height of the ice. Penguins were maintained in a corral on the fast ice in Antarctica, and voluntarily dived through two artificial ice holes. Data loggers were deployed on the penguins to monitor under water behavior. Nine instrumented penguins performed 386 leaps from the holes during experiments. The maximum swim speeds within 1 s before the exits through the holes correlated significantly with the above-water height of the holes. Penguins adopted higher speed to exit through the higher holes than through the lower holes. Speeds of some failed exits were lower than the theoretical minimum values to reach a given height. Penguins failed to exit onto the sea ice in a total of 37 of the trials. There was no preference to use lower holes after they failed to exit through the higher holes. Rather, swim speed was increased for subsequent attempts after failed leaps. These data demonstrated that penguins apparently recognized the above-water height of holes and adopted speeds greater than the minimal vertical speeds to reach the exit height. It is likely, especially in the case of higher holes (>40 cm), that they chose minimum speeds to exit through the holes to avoid excess energy for swimming before leaping. However, some exceptionally high speeds were recorded when they directly exited onto the ice from lower depths. In those cases, birds could increase swim speed without strokes for the final seconds before exit and they only increased the steepness of their body angles as they surfaced, which indicates that the speed required for leaps by emperor penguins were aided by

  13. Swarming Speed Control for DC Permanent Magnet Motor Drive via Pulse Width Modulation Technique and DC/DC Converter

    Directory of Open Access Journals (Sweden)

    A.S. Oshaba

    2013-05-01

    Full Text Available This study presents an approach for the speed control of a permanent magnet DC motor drive via Pulse Width Modulation (PWM technique and a DC/DC converter. The Particle Swarm Optimization (PSO technique is used to minimize a time domain objective function and obtain the optimal controller parameters. The performance of the proposed technique has been evaluated using various types of disturbances including load torque variations. Simulation results illustrate clearly the robustness of the controller and validity of the design technique for controlling the speed of permanent magnet motors.

  14. Modern power converter drives. Drive systems, power electronics, machines, mechatronics and motion control. 5. rev. and enl. ed.; Moderne Stromrichterantriebe. Antriebssystem, Leistungselektronik, Maschinen, Mechatronik und Motion Control, Arbeitsweise drehzahlveraenderbarer Antriebe mit Stromrichtern und Antriebsvernetzung

    Energy Technology Data Exchange (ETDEWEB)

    Brosch, P.F.

    2008-07-01

    This book informs students and practicians on variable-speed drives. Constructional engineers, technicians and others are given a practical tool for their daily work. - Fundamentals of motive power engineering - power converter components - electric machines - power converter drives with commutator motors - power converter drives with induction machines - integrated drive systems - motion control and mechatronics - selection and dimensioning of variable-speed drives converter measuring engineering - electromagnetic compatibility, with examples - measurements on power converter drives with variable speed adjustment - electromagnetic compatibility. (orig./GL)

  15. Dynamic Harmonic and Reactive Power Compensation with an Adaptive Shunt Active Filter for Variable Speed Induction Motor Drive

    OpenAIRE

    Sindhu M R; Aneesh P; Manjula G Nair; T N P Nambiar

    2014-01-01

    Variable speed drives are mostly preferred in industries, while considering energy saving, smooth control, flexible operation and fast response. On the other hand, this equipment generates dynamic harmonic distortions in source currents and draws variable reactive power demand depending on variation in load condition. These distortions propagate throughout the system and affect all the loads connected to the point of common coupling. Hence a dynamic harmonic and reactive compensator is necess...

  16. Feed drive modelling for the simulation of tool path tracking in multi-axis High Speed Machining

    CERN Document Server

    Prévost, David; Lartigue, Claire; Dumur, Didier

    2011-01-01

    Within the context of High Speed Machining, it is essential to manage the trajectory generation to achieve both high surface quality and high productivity. As feed drives are one part of the set Machine tool - Numerical Controller, it is necessary to improve their performances to optimize feed drive dynamics during trajectory follow up. Hence, this paper deals with the modelling of the feed drive in the case of multi axis machining. This model can be used for the simulation of axis dynamics and tool-path tracking to tune parameters and optimize new frameworks of command strategies. A procedure of identification based on modern NC capabilities is presented and applied to industrial HSM centres. Efficiency of this modelling is assessed by experimental verifications on various representative trajectories. After implementing a Generalized Predictive Control, reliable simulations are performed thanks to the model. These simulations can then be used to tune parameters of this new framework according to the tool-pat...

  17. Dynamic Modeling of Adjustable-Speed Pumped Storage Hydropower Plant: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, E.; Singh, M.; Gevorgian, V.; Mohanpurkar, M.; Havsapian, R.; Koritarov, V.

    2015-04-06

    Hydropower is the largest producer of renewable energy in the U.S. More than 60% of the total renewable generation comes from hydropower. There is also approximately 22 GW of pumped storage hydropower (PSH). Conventional PSH uses a synchronous generator, and thus the rotational speed is constant at synchronous speed. This work details a hydrodynamic model and generator/power converter dynamic model. The optimization of the hydrodynamic model is executed by the hydro-turbine controller, and the electrical output real/reactive power is controlled by the power converter. All essential controllers to perform grid-interface functions and provide ancillary services are included in the model.

  18. Very-low-speed variable-structure control of sensorless induction machine drives without signal injection

    DEFF Research Database (Denmark)

    Lascu, Christian; Boldea, Ion; Blaabjerg, Frede

    2005-01-01

    A sensorless induction machine drive is presented, in which the principles of variable-structure control and direct torque control (DTC) are combined to ensure high-performance operation in the steady state and under transient conditions. The drive employs a new torque and flux controller, the "l...

  19. A Novel Adjustment Method for Shearer Traction Speed through Integration of T-S Cloud Inference Network and Improved PSO

    Directory of Open Access Journals (Sweden)

    Lei Si

    2014-01-01

    Full Text Available In order to efficiently and accurately adjust the shearer traction speed, a novel approach based on Takagi-Sugeno (T-S cloud inference network (CIN and improved particle swarm optimization (IPSO is proposed. The T-S CIN is built through the combination of cloud model and T-S fuzzy neural network. Moreover, the IPSO algorithm employs parameter automation adjustment strategy and velocity resetting to significantly improve the performance of basic PSO algorithm in global search and fine-tuning of the solutions, and the flowchart of proposed approach is designed. Furthermore, some simulation examples are carried out and comparison results indicate that the proposed method is feasible, efficient, and is outperforming others. Finally, an industrial application example of coal mining face is demonstrated to specify the effect of proposed system.

  20. African elephants adjust speed in response to surface-water constraint on foraging during the dry-season.

    Science.gov (United States)

    Chamaillé-Jammes, Simon; Mtare, Godfrey; Makuwe, Edwin; Fritz, Hervé

    2013-01-01

    Most organisms need to acquire various resources to survive and reproduce. Individuals should adjust their behavior to make optimal use of the landscape and limit the costs of trade-offs emerging from the use of these resources. Here we study how African elephants Loxodonta africana travel to foraging places between regular visits to waterholes. Elephant herds were tracked using GPS collars during two consecutive dry seasons in Hwange National Park, Zimbabwe. We segmented each individual movement track at each visit to water to define foraging trips, and then used trip-level statistics to build an understanding of movement strategies. Travel speed within these individually-consistent movement bouts was also analyzed to understand if speed was better linked to distance to water or progression in the trip over time. We found that elephants went further from water when drinking less often, which could result from a trade-off between drinking and foraging in less depleted, far from water, places. Speed increased towards the beginning and the end of the trips, and was also greater than observed during the wet season, suggesting that elephants were trying to save time. Numerous short trips traveled at greater speed, particularly when commuting to a different waterhole, was tentatively explained by the inability to drink at specific waterholes due to intra-specific interference. Unexpectedly elephants did not always minimize travel time by drinking at the closest waterhole, but the extra distance traveled remained never more than a few kilometers. Our results show how individuals may adjust movement behavior to deal with resource trade-offs at the landscape scale. We also highlight how behavioral context, here progression in the trip, may be more important than spatial context, here distance to water, in explaining animal movement patterns.

  1. African elephants adjust speed in response to surface-water constraint on foraging during the dry-season.

    Directory of Open Access Journals (Sweden)

    Simon Chamaillé-Jammes

    Full Text Available Most organisms need to acquire various resources to survive and reproduce. Individuals should adjust their behavior to make optimal use of the landscape and limit the costs of trade-offs emerging from the use of these resources. Here we study how African elephants Loxodonta africana travel to foraging places between regular visits to waterholes. Elephant herds were tracked using GPS collars during two consecutive dry seasons in Hwange National Park, Zimbabwe. We segmented each individual movement track at each visit to water to define foraging trips, and then used trip-level statistics to build an understanding of movement strategies. Travel speed within these individually-consistent movement bouts was also analyzed to understand if speed was better linked to distance to water or progression in the trip over time. We found that elephants went further from water when drinking less often, which could result from a trade-off between drinking and foraging in less depleted, far from water, places. Speed increased towards the beginning and the end of the trips, and was also greater than observed during the wet season, suggesting that elephants were trying to save time. Numerous short trips traveled at greater speed, particularly when commuting to a different waterhole, was tentatively explained by the inability to drink at specific waterholes due to intra-specific interference. Unexpectedly elephants did not always minimize travel time by drinking at the closest waterhole, but the extra distance traveled remained never more than a few kilometers. Our results show how individuals may adjust movement behavior to deal with resource trade-offs at the landscape scale. We also highlight how behavioral context, here progression in the trip, may be more important than spatial context, here distance to water, in explaining animal movement patterns.

  2. Low-Driving-Voltage Optical Modulation Utilizing FWM for High-Speed Transmission Systems

    Institute of Scientific and Technical Information of China (English)

    Akihiko; Matsuura; Toshiya; Matsuda; Tomoyoshi; Kataoka

    2003-01-01

    We propose an optical transmitter with reduced modulator driving voltage. This reduction is achieved through an on-off ratio improvement technique based on FWM. We confirmed the feasibility of the method in a 43-Gbit/s experiment.

  3. Rapid trait evolution drives increased speed and variance in experimental range expansions

    Science.gov (United States)

    Weiss-Lehman, Christopher; Hufbauer, Ruth A; Melbourne, Brett A

    2017-01-01

    Range expansions are central to two ecological issues reshaping patterns of global biodiversity: biological invasions and climate change. Traditional theory considers range expansion as the outcome of the demographic processes of birth, death and dispersal, while ignoring the evolutionary implications of such processes. Recent research suggests evolution could also play a critical role in determining expansion speed but controlled experiments are lacking. Here we use flour beetles (Tribolium castaneum) to show experimentally that mean expansion speed and stochastic variation in speed are both increased by rapid evolution of traits at the expansion edge. We find that higher dispersal ability and lower intrinsic growth rates evolve at the expansion edge compared with spatially nonevolving controls. Furthermore, evolution of these traits is variable, leading to enhanced variance in speed among replicate population expansions. Our results demonstrate that evolutionary processes must be considered alongside demographic ones to better understand and predict range expansions. PMID:28128350

  4. Electric Drive Control with Rotor Resistance and Rotor Speed Observers Based on Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    C. Ben Regaya

    2014-01-01

    Full Text Available Many scientific researchers have proposed the control of the induction motor without speed sensor. These methods have the disadvantage that the variation of the rotor resistance causes an error of estimating the motor speed. Thus, simultaneous estimation of the rotor resistance and the motor speed is required. In this paper, a scheme for estimating simultaneously the rotor resistance and the rotor speed of an induction motor using fuzzy logic has been developed. We present a method which is based on two adaptive observers using fuzzy logic without affecting each other and a simple algorithm in order to facilitate the determination of the optimal values of the controller gains. The control algorithm is proved by the simulation tests. The results analysis shows the characteristic robustness of the two observers of the proposed method even in the case of variation of the rotor resistance.

  5. Experimental Performance Evaluation of a High Speed Permanent Magnet Synchronous Motor and Drive for a Flywheel Application at Different Frequencies

    Science.gov (United States)

    Nagorny, Aleksandr S.; Jansen, Ralph H.; Kankam, M. David

    2007-01-01

    This paper presents the results of an experimental performance characterization study of a high speed, permanent magnet motor/generator (M/G) and drive applied to a flywheel module. Unlike the conventional electric machine the flywheel M/G is not a separated unit; its stator and rotor are integrated into a flywheel assembly. The M/G rotor is mounted on a flywheel rotor, which is magnetically levitated and sealed within a vacuum chamber during the operation. Thus, it is not possible to test the M/G using direct load measurements with a dynamometer and torque transducer. Accordingly, a new in-situ testing method had to be developed. The paper describes a new flywheel M/G and drive performance evaluation technique, which allows the estimation of the losses, efficiency and power quality of the flywheel high speed permanent magnet M/G, while working in vacuum, over wide frequency and torque ranges. This method does not require any hardware modification nor any special addition to the test rig. This new measurement technique is useful for high-speed applications, when applying an external load is technically difficult.

  6. Brushless DC Motor Drive during Speed Regulation with Artificial Neural Network Controller

    OpenAIRE

    Sakshi Solanki

    2016-01-01

    Brushless DC motor, at this moment is extensively used being many industrial functions due to the different features like high efficiency and dynamic response and high speed range. This paper is proposing a technology named as Artificial Neural Network controller to control the speed of the brushless DC motor. Here the paper contributes an analysis of performance Artificial Neural Network controller. Because it is difficult to handle by the use of conventional PID controller as BL...

  7. Driving behaviour responses to a moose encounter, automatic speed camera, wildlife warning sign and radio message determined in a factorial simulator study.

    Science.gov (United States)

    Jägerbrand, Annika K; Antonson, Hans

    2016-01-01

    In a driving simulator study, driving behaviour responses (speed and deceleration) to encountering a moose, automatic speed camera, wildlife warning sign and radio message, with or without a wildlife fence and in dense forest or open landscape, were analysed. The study consisted of a factorial experiment that examined responses to factors singly and in combination over 9-km road stretches driven eight times by 25 participants (10 men, 15 women). The aims were to: determine the most effective animal-vehicle collision (AVC) countermeasures in reducing vehicle speed and test whether these are more effective in combination for reducing vehicle speed; identify the most effective countermeasures on encountering moose; and determine whether the driving responses to AVC countermeasures are affected by the presence of wildlife fences and landscape characteristics. The AVC countermeasures that proved most effective in reducing vehicle speed were a wildlife warning sign and radio message, while automatic speed cameras had a speed-increasing effect. There were no statistically significant interactions between different countermeasures and moose encounters. However, there was a tendency for a stronger speed-reducing effect from the radio message warning and from a combination of a radio message and wildlife warning sign in velocity profiles covering longer driving distances than the statistical tests. Encountering a moose during the drive had the overall strongest speed-reducing effect and gave the strongest deceleration, indicating that moose decoys or moose artwork might be useful as speed-reducing countermeasures. Furthermore, drivers reduced speed earlier on encountering a moose in open landscape and had lower velocity when driving past it. The presence of a wildlife fence on encountering the moose resulted in smaller deceleration.

  8. Adjustments with running speed reveal neuromuscular adaptations during landing associated with high mileage running training.

    Science.gov (United States)

    Verheul, Jasper; Clansey, Adam C; Lake, Mark J

    2016-12-08

    It remains to be determined whether running training influences the amplitude of lower limb muscle activations prior to and during the first half of stance, and whether such changes are associated with joint stiffness regulation and usage of stored energy from tendons. Therefore, the aim of this study was to investigate neuromuscular and movement adaptations before and during landing in response to running training across a range of speeds. Two groups of high mileage (HM; >45 km/wk, n=13) and low mileage (LM; muscular activations before landing. Estimated elastic work about the ankle was found to be higher in the HM runners which might play a role in reducing weight acceptance phase muscle activation levels and improve muscle activation efficiency with running training.

  9. Using LDR as Sensing Element for an External Fuzzy Controller Applied in Photovoltaic Pumping Systems with Variable-Speed Drives.

    Science.gov (United States)

    Maranhão, Geraldo Neves De A; Brito, Alaan Ubaiara; Leal, Anderson Marques; Fonseca, Jéssica Kelly Silva; Macêdo, Wilson Negrão

    2015-09-22

    In the present paper, a fuzzy controller applied to a Variable-Speed Drive (VSD) for use in Photovoltaic Pumping Systems (PVPS) is proposed. The fuzzy logic system (FLS) used is embedded in a microcontroller and corresponds to a proportional-derivative controller. A Light-Dependent Resistor (LDR) is used to measure, approximately, the irradiance incident on the PV array. Experimental tests are executed using an Arduino board. The experimental results show that the fuzzy controller is capable of operating the system continuously throughout the day and controlling the direct current (DC) voltage level in the VSD with a good performance.

  10. Using LDR as Sensing Element for an External Fuzzy Controller Applied in Photovoltaic Pumping Systems with Variable-Speed Drives

    Directory of Open Access Journals (Sweden)

    Geraldo Neves De A. Maranhão

    2015-09-01

    Full Text Available In the present paper, a fuzzy controller applied to a Variable-Speed Drive (VSD for use in Photovoltaic Pumping Systems (PVPS is proposed. The fuzzy logic system (FLS used is embedded in a microcontroller and corresponds to a proportional-derivative controller. A Light-Dependent Resistor (LDR is used to measure, approximately, the irradiance incident on the PV array. Experimental tests are executed using an Arduino board. The experimental results show that the fuzzy controller is capable of operating the system continuously throughout the day and controlling the direct current (DC voltage level in the VSD with a good performance.

  11. A Class of Speed-Sensorless Sliding-Mode Observers for High-Performance Induction Motor Drives

    DEFF Research Database (Denmark)

    Lascu, Christian; Boldea, Ion; Blaabjerg, Frede

    2009-01-01

    A new family of speed-sensorless sliding-mode observers for induction motor drives has been developed. Three topologies are investigated in order to determine their feasibility, parameter sensitivity, and practical applicability. The most significant feature of all schemes is that they do...... not require the rotor speed adaptation, i.e., they are inherently sensorless observers. The most versatile and robust is a dual-reference-frame full-order flux observer. The other two schemes are flux observers implemented in stator frame and rotor frame, respectively. These are simpler than the first one...... and make use of the sliding-mode invariance over a specified range of modeling uncertainties and disturbances.Main theoretical aspects, results of parameter sensitivity analysis, and implementation details are given for each observer in order to allow the comparison. Experimental results with the dual...

  12. Sensorless Stator Field-Oriented Controlled IM Drive at Low Speed with Rr Estimator

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Pu

    2014-01-01

    Full Text Available This paper pertains to a technique of a sensorless indirect stator field-oriented induction motor control, which prevents the accumulative errors incurred by the integrator and the problem relating to the stability of the control system caused by the stator resistance susceptible to temperature variations while conducting the flux estimation directly and computing the synchronous rotary speed. The research adds an adaptive flux observer to estimate the speed of the rotor and uses the fixed trace algorithm (FTA to execute an online estimation of the slip difference, thereby improving the system of stability under the low rotary speed at regenerating mode and the influence of the rotor resistance on the slip angle. Finally, the paper conducts simulations by Simulink of MATLAB and practices to verify the correctness of the result the paper presents.

  13. A Class of Speed Sensorless Sliding Mode Observers for Direct Torque Controlled Induction Motor Drives

    DEFF Research Database (Denmark)

    Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede

    2004-01-01

    A family of speed-sensorless sliding-mode observers for induction motors has been developed. Three topologies have been investigated in order to determine their feasibility, parameter sensitivity and practical applicability. The salient feature of all schemes is that they do not require the rotor...... speed adaptation, that is, they are inherently sensorless observers. The most versatile is a dual-reference-frame observer. The other two schemes, implemented in stator frame and rotor frame, respectively, are simpler and are insensitive to detuning some of the motor parameters. Main theoretical aspects......, results of parameter sensitivity analysis, and implementation details are given for each scheme. Experimental results with the dual-reference- frame observer, considered most adequate for practical applications, are presented and discussed. Sensorless operation at very low speeds is demonstrated...

  14. Circuit Regulates Speed Of dc Motor

    Science.gov (United States)

    Weaver, Charles; Padden, Robin; Brown, Floyd A., Jr.

    1990-01-01

    Driving circuit regulates speed of small dc permanent-magnet motor in tape recorder. Two nested feedback loops maintain speed within 1 percent of constant value. Inner loop provides coarse regulation, while outer loop removes most of variation in speed that remains in the presence of regulation by the inner loop. Compares speed of motor with commanded speed and adjusts current supplied to motor accordingly.

  15. Exploration of combined adjustment laws about IGV,stator and rotational speed in off-design conditions in an axial compressor

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Experimental investigations are performed in a three-stage low-speed axial compressor with variable inlet guide vanes(IGV) and adjustable stators.The characteristics of the compressor,especially the efficiency and stall margin,are analyzed in design and off-design operation conditions by adjusting stagger angles of IGV and stators as well as changing the rotational speed.The experimental results show that the off-design performance of the multistage axial compressor is improved by restaggering of IGV and stators related to rotational speed.Considering the background of engineering applications,digital signal processing(DSP) technique is used to realize online adjustment of stagger angles according to the corresponding relations between incidence angles of rotor and rotational speed.

  16. Comparative Study between PI and FUZZY Logic Speed Controller in Vector Controlled PMSM Drive

    Directory of Open Access Journals (Sweden)

    Kaushik Jash

    2014-04-01

    Full Text Available This paper is concerned with vector control of permanent magnet synchronous motor (PMSM using two different type of speed controller, one is PI controller and another is FUZZY logic controller. Although Proportional Integral Controller usually preferred as a speed controller due to its fixed gain and integral time constant but the performance of PI controller is affected by parameter variation, such as load changing, speed variation etc. In PI controller THD of the stator phase current is more and torque ripple also more. To avoid this problem here we used FUZZY logic controller. In this paper the mathematical model of PMSM, using the powerful simulation modeling capabilities of Matlab/Simulink is implemented. The entire PMSM control system is divided into several independent functional modules such as PMSM body module, inverter module and coordinate transformation module and Sinusoidal pulse width modulation (SPWM production module and so on. Here we used two loops, one is outer loop known as speed control loop, another is inner loop called current loop. we can analyzed a variety of simulation waveforms and it provide an effective means for the analysis and design of the PMSM control system.

  17. Dynamic Analysis of Fluid Power Drive-trains for Variable Speed Wind Turbines: a Parameter Study

    NARCIS (Netherlands)

    Jarquin Laguna, A.; Diepeveen, N.F.B.

    2013-01-01

    In the pursuit of making wind energy technology more economically attractive, the application of fluid power technology for the transmission of wind energy is being developed by several parties all over the world. This paper presents a dynamic model of a fluid power transmission for variable speed w

  18. Variable speed drives for pumps used in intensive pond culture systems

    Science.gov (United States)

    Prior to about 2010, the only large pumps on most catfish farms were those associated with the water supply. Water from wells is usually pumped to the surface using single-speed, vertical, lineshaft turbine pumps powered by three phase, electric motors. Since 2010, several catfish farmers have bui...

  19. Multi-scale calculation of settling speed of coarse particles by accelerated Stokesian dynamics without adjustable parameter

    Institute of Scientific and Technical Information of China (English)

    Long Wang; Jiachun Li; Jifu Zhou

    2009-01-01

    The calculation of settling speed of coarse parti-cles is firstly addressed, with accelerated Stokesian dynamics without adjustable parameters, in which far field force act-ing on the particle instead of particle velocity is chosen as dependent variables to consider inter-particle hydrodynamic interactions. The sedimentation of a simple cubic array of spherical particles is simulated and compared to the results available to verify and validate the numerical code and computational scheme. The improved method keeps the same computational cost of the order O(Nlog N) as usual accelerated Stokesian dynamics does. Then, more realistic random suspension sedimentation is investigated with the help of Mont Carlo method. The computational results agree well with experimental fitting. Finally, the sedimentation of finer cohesive particle, which is often observed in estuary environment, is presented as a further application in coastal engineering.

  20. Structure of 15-Level Sub-Module Cascaded H-Bridge Inverter for Speed Control of AC Drive Applications

    Directory of Open Access Journals (Sweden)

    R. Uthirasamy

    2015-02-01

    Full Text Available This paper deals with the implementation of a single phase 15-level Sub-Multilevel Cascaded H-Bridge Inverter (SMCHBI for variable speed industrial drive applications. It consists of sub-multilevel modules and H-bridge inverter configuration. Sub-multilevel switches synthesize stepped DC link voltage and current from the DC sources. H-bridge inverter switches renovate stepped DC link voltage and current into sinusoidal waveform. Compared with conventional Cascaded Multilevel Inverter (CMLI, the proposed system employs the reduced number of power switches, DC sources and gate driver requirements. The proposed system not only reduces the overall system cost but also reduces the voltage stress across the inverter switches. The proposed system does not required additional resonant soft switching circuits for Zero Voltage Switching (ZVS of inverter. In the proposed method, variable frequency method is adopted for the speed control of industrial induction motor drives. A prototype model of 15-level SMCHB is developed and the performance of the systems is validated experimentally.

  1. An enhanced Z-source inverter topology-based permanent magnet brushless DC motor drive speed control

    Science.gov (United States)

    Geno Peter, P.; Rajaram, M.

    2015-08-01

    In this paper, an enhanced Z-source inverter (ZSI) is introduced for controlling the speed of permanent magnet brushless DC motor (PMBLDCM) drive. It is the extension of the conventional ZSI and the elements used in the circuit are the same as those of the conventional ZSI, except that the position of Inverter Bridge and diode would be exchanged from the classical circuit diagram. This exchanged circuit avoids the startup path of the inrush current and hence reduces the inrush current and improves the motor efficiency. Different modes of enhanced ZSI are studied with PMBLDCM. The voltage polarity of Z-source capacitors in the proposed circuit is the same as that of the input voltage polarity. Furthermore, to get the same voltage boost, the capacitor voltage stress is reduced to a significant extent. The speed control capability of the proposed brushless DC motor drive is compared with that of the conventional ZSI. The proposed ZSI is implemented in MATLAB/Simulink working platform and the output performance is evaluated. Also, the performance of voltage ratio is analysed both by simulation and mathematical models. All these analyses are known to express the innovative features of the proposed system.

  2. Electron Drift Speed And Current-Induced Drive Torques On A Domain Wall

    Science.gov (United States)

    Berger, Luc

    2009-03-01

    It has become fashionable to describe [1] current-induced torques on a DW in terms of an electron drift speed u = - P*j*muB/e*M where muB is the Bohr magneton and M the saturation magnetization. While appropriate for adiabatic torques, this quantity u is misleading and not the best choice in the case of non-adiabatic torques. For example, it leads [2] to beta not equal to alpha, where beta represents the intensity of the non-adiabatic torque, and alpha is the damping parameter. By writing equations of motion for conduction- electron spins in a moving frame where the electron gas is at rest, we find [3] a direct relation between damping and non- adiabatic torques. The correct electron drift speed turns out to be the speed of the frame, and is v = P*j/(n*q) where n and q are the carrier density and charge. It is related to the ordinary Hall constant R0 by v P*R0*j. After substituting v for u in the expression of the non-adiabatic torque, we find that beta = alpha holds now. Because v is larger than u in Permalloy, it can explain better the large current-induced DW speeds found [4] experimentally. In materials where R0> 0 and the carriers are dominantly hole-like, v and u have opposite signs, leading to different predictions for the sense of DW motion. We discuss examples of such materials. 1. G. Tatara and H. Kohno, Phys. Rev. Lett. 92, 086601 (2004). 2. H. Kohno et al., J. Phys. Soc. Japan, 75, 113706 (2006). 3. L. Berger, Phys. Rev. B 75, 174401 (2007). 4. M. Hayashi et al., Phys. Rev. Lett. 98, 037204 (2007).

  3. Wavelet-Fuzzy Speed Indirect Field Oriented Controller for Three-Phase AC Motor Drive

    DEFF Research Database (Denmark)

    Sanjeevikumar, Padmanaban; Daya, Febin; Blaabjerg, Frede

    2016-01-01

    wavelet transform and the fuzzy logic controller, to generate the scaled gains for the indirect FOC induction motor. Complete model of the proposed ac motor drive is developed with numerical simulation Matlab/Simulink software and tested under different working conditions. For experimental verification......, a hardware prototype was implemented and the control algorithm is framed using TMS320F2812 digital signal processor (dsp). Both simulation and hardware results presented in this paper are shown in close agreement and conformity about the suitability for industrial applications....

  4. Improvement of power system stability by high speed power control of adjustable speed machine; Kahensokuki no koshutsuryoku seigyo ni yoru denryoku keito no anteido kojo

    Energy Technology Data Exchange (ETDEWEB)

    Nojiri, K.; Kikuchi, T.; Nakagawa, H. [Kansai Electric Power Co. Inc., Osaka (Japan); Goto, M. [Hitachi, Ltd., Tokyo (Japan); Nohara, H. [Hitachi Nuclear Engineering Co. Ltd., Tokyo (Japan)

    1997-01-20

    Large capacity adjustable speed machines (ASMs) at pumped storage power station have been put into full operation and the operating characteristics of ASM have been highly evaluated from the view point of power system operation. The output power (input power) of ASM can be controlled very quickly by applying a vector control scheme to the excitation control. This quick responsive feature of ASM can make it possible to improve the stability of the neighbor sub-power system. For improvement of transient stability, the output power of ASM is reduced very quickly in order to control the acceleration of neighbor generators during and after transmission line faults. For improvement of dynamic stability, the output power of ASM is modulated in accordance with the stabilizing signals detected from the swing of generator rotor or the power flow fluctuation on the transmission line. This paper describes the design concepts and method of control system for improving the transient and dynamic stability and proposes a power system stabilizing control system. The effects of the proposed stabilizing control system have been verified by a power system simulator. 9 refs., 15 figs., 1 tab.

  5. MRAS speed estimator with fuzzy and PI stator resistance adaptation for sensorless induction motor drives using RT-lab

    Directory of Open Access Journals (Sweden)

    S. Mohan Krishna

    2016-09-01

    Full Text Available This paper presents a real-time simulation study of Model Reference Adaptive System based rotor speed estimator with parallel stator resistance adaptation mechanism for speed sensorless induction motor drive. Both, the traditional Proportional Integral and Fuzzy logic based control mechanisms are utilised for stator resistance adaptation, while, the rotor speed is estimated parallely by means of Proportional Integral based mechanism. The estimator's response to dynamic changes in Load perturbation and doubling of the nominal value of the actual stator resistance of the motor is observed. The superiority of the fuzzy based stator resistance adaptation in the Model Reference Adaptive System estimator is proved through results validated in real-time. The purpose of employing a fairly new real-time platform is to reduce the test and prototype time. The model is initially built using Matlab/Simulink blocksets and the results are validated in real time using RT-Lab. The RT-lab blocksets are integrated into the Simulink model and then executed in real-time using the OP-4500 target developed by Opal-RT. The real-time simulation results are observed in the workstation.

  6. Interpolating gain-scheduled H∞ loop shaping design for high speed ball screw feed drives.

    Science.gov (United States)

    Dong, Liang; Tang, WenCheng; Bao, DaFei

    2015-03-01

    This paper presents a method to design servo controllers for flexible ball screw drives with time-varying dynamics, which are mainly due to the time-varying table position and the workpiece mass. A gain-scheduled H∞ loop shaping controller is designed to achieve high tracking performance against the dynamic variations. H∞ loop shaping design procedure incorporates open loop shaping by a set of compensators to obtain performance/robust stability tradeoffs. The interpolating gain-scheduled controller is obtained by interpolating the state space model of the linear time-invariant (LTI) controllers estimated for fixed values of the scheduling parameters and a linear least squares problem can be solved. The proposed controller has been compared with P/PI with velocity and acceleration feedforward and adaptive backstepping sliding mode control experimentally. The experimental results indicate that the tracking performance has been improved and the robustness for time-varying dynamics has been achieved with the proposed scheme.

  7. Chronic Inflammation-Related HPV: A Driving Force Speeds Oropharyngeal Carcinogenesis.

    Science.gov (United States)

    Liu, Xin; Ma, Xiangrui; Lei, Zhengge; Feng, Hao; Wang, Shasha; Cen, Xiao; Gao, Shiyu; Jiang, Yaping; Jiang, Jian; Chen, Qianming; Tang, Yajie; Tang, Yaling; Liang, Xinhua

    2015-01-01

    Oropharyngeal squamous cell carcinoma (OPSCC) has been known to be a highly aggressive disease associated with human papilloma virus (HPV) infection. To investigate the relationship between HPV and chronic inflammation in oropharyngeal carcinogenesis, we collected 140 oral mucous fresh specimens including 50 OPSCC patients, 50 cancer in situ, 30 precancerous lesions, and 10 normal oral mucous. Our data demonstrated that there was a significantly higher proportion of severe chronic inflammation in dysplastic epithelia in comparison with that in normal tissues (Pchronic inflammation degrees from mild to severe inflammation (Pinflammation response and immune suppression in HPV-positive OPSCC. These indicated that persistent chronic inflammation-related HPV infection might drive oropharyngeal carcinogenesis and MDSCs might pay an important role during this process. Thus, a combination of HPV infection and inflammation expression might become a helpful biomedical marker to predict oropharyngeal carcinogenesis.

  8. Two-Speed Epicyclic Final Drives for 14-Ton Amphibious Vehicle

    Science.gov (United States)

    1985-01-18

    inside F’.D.(oF) 17:45:01 13:50:01 13:55:01 14:00:00 14z05z00 FD Output Fowe- (hp) 32 31 31 32 31 Output T orque (lb-ft) 1674 1663 1645 1475 1448 FD Output...Output T orque (lb-f!) -47) -486 -430 -387 -509 FD Output Saeed(rp) 367 36. 367 Z66 367 FD Input Speed (rpm) 1642 1642 1642 1645 1644 Pump Spend (rpm...08s24,12 08&25CO0 08:30:01 08:37g17 0840,01 FD Output Power (hp) 42 62 30 71 63 OutFut ’ orque (lb-fL) 471 706 i01e 1607 1407 FD Out.ut Soeed ipm) 465

  9. High-Speed Current dq PI Controller for Vector Controlled PMSM Drive

    Directory of Open Access Journals (Sweden)

    Mohammad Marufuzzaman

    2014-01-01

    Full Text Available High-speed current controller for vector controlled permanent magnet synchronous motor (PMSM is presented. The controller is developed based on modular design for faster calculation and uses fixed-point proportional-integral (PI method for improved accuracy. Current dq controller is usually implemented in digital signal processor (DSP based computer. However, DSP based solutions are reaching their physical limits, which are few microseconds. Besides, digital solutions suffer from high implementation cost. In this research, the overall controller is realizing in field programmable gate array (FPGA. FPGA implementation of the overall controlling algorithm will certainly trim down the execution time significantly to guarantee the steadiness of the motor. Agilent 16821A Logic Analyzer is employed to validate the result of the implemented design in FPGA. Experimental results indicate that the proposed current dq PI controller needs only 50 ns of execution time in 40 MHz clock, which is the lowest computational cycle for the era.

  10. Performance Analysis of DTC-SVM Sliding Mode Controllers-Based Parameters Estimator of Electric Motor Speed Drive

    Directory of Open Access Journals (Sweden)

    Fatma Ben Salem

    2014-01-01

    Full Text Available This paper is concerned with a framework which unifies direct torque control space vector modulation (DTC-SVM and variable structure control (VSC. The result is a hybrid VSC-DTC-SVM controller design which eliminates several major limitations of the two individual controls and retains merits of both controllers. It has been shown that obtained control laws are very sensitive to variations of the stator resistance, the rotor resistance, and the mutual inductance. This paper discusses the performances of adaptive controllers of VSC-DTC-SVM monitored induction motor drive in a wide speed range and even in the presence of parameters uncertainties and mismatching disturbances. Better estimations of the stator resistance, the rotor resistance, and the mutual inductance yield improvements of induction motor performances using VSC-DTC-SVM, thereby facilitating torque ripple minimization. Simulation results verified the performances of the proposed approach.

  11. Experimental Voltage Stabilization of a Variable Speed Wind Turbine Driving Synchronous Generator using STATCOM based on Genetic Algorithm

    Science.gov (United States)

    El-Zoghby, Helmy M.; Bendary, Ahmed F.

    2016-10-01

    In this paper Static Synchronous Compensator (STATCOM) is used for improving the performance of the power grid with wind turbine that drives synchronous generator. The main feature of the STATCOM is that it has the ability to absorb or inject rapidly reactive power to grid. Therefore the voltage regulation of the power grid with STATCOM device is achieved. STATCOM also improves the stability of the power system after occurring severe disturbance such as faults, or suddenly step change in wind speed. The proposed STATCOM controller is a Proportional-Integral (PI) controller tuned by Genetic Algorithm (GA). An experimental model was built in Helwan University to the proposed system. The system is tested at different operating conditions. The experimental results prove the effectiveness of the proposed STATCOM controller in damping the power system oscillations and restoring the power system voltage and stability.

  12. High- Speed railway lines in Germany: Experience in Tunnelling in Karstic Geology and Discussion oF Tunnel Driving Methods

    Institute of Scientific and Technical Information of China (English)

    Rudolf Pottler

    2004-01-01

    In the course of Deutsche Bahn's new high - speed railway line between Nuremberg and Ingolstadt, a number of tunnels are being constructed, with a total length of about 15 km. One of the longest tunnel is the 7,250 m long Irlahüll tunnel.The tunnel was driven in karst geology. It was not expected that karst phenomena would be so widespread. This forced client, designer and contractor to take a new approach to the project. Different tools were developed to handle the problems on site. Additional site investigations had to be performed to identify karst phenomena in the vicinity of the tunnel. For validating the stability and serviceability of the tunnel, a new way of defining the probability of failure of the construction had to be found. Based on the experience of the tunnel driving at the high - speed railway line in Germany between Nuremberg and Ingolstadt, two different methods of tunnelling are discussed: Drill and blast ( New Austrian Tunnelling Method: NATM) and the use of tunnel boring machines (TBM).

  13. Minimization and identification of conducted emission bearing current in variable speed induction motor drives using PWM inverter

    Indian Academy of Sciences (India)

    A Ramachandran; M Channa Reddy; Ranjan Moodithaya

    2008-10-01

    The recent increase in the use of speed control of ac induction motor for variable speed drive using pulse width modulation (PWM) inverter is due to the advent of modern power electronic devices and introduction of microprocessors. There are many advantages of using ac induction motor for speed control applicatons in process and aerospace industries, but due to fast switching of the modern power electronic devices, the parasitic coupling produces undesirable effects. The undesirable effects include radiated and conducted electromagnetic interference (EMI) which adversely affect nearby computers, electronic/electrical instruments and give rise to the flow of bearing current in the induction motor. Due to the flow of bearing current in the induction motor, electrical discharge machining takes place in the inner race of the bearing which reduces the life of the bearing. In high power converters and inverters, the conducted and radiated emissions become a major concern. In this paper, identification of bearing current due to conducted emission, the measurement of bearing current in a modified induction motor and to minimize the bearing current are discussed. The standard current probe, the standard line impedance stabilization network (LISN)), the electronics interface circuits are used to measure high frequency common mode current, bearing current and to minimize the conducted noise from the system. The LISN will prevent the EMI noise entering the system from the supply source by conductive methods, at the same time prevents the EMI generated if any due to PWM, fast switching in the system, will not be allowed to enter the supply line. For comparing the results with Federal Communications Commission (FCC) and Special Committee on Radio Interference (CISPR) standards, the graphs are plotted with frequency Vs, line voltage in $dB{_\\mu} V$, common mode voltage in $dB{_\\mu} V$ and the bearing current in $dB_{\\mu} A$ with out and with minimizing circuits.

  14. Space and time harmonics related problems and their mitigation for position and speed sensorless slip-ring induction motor drives applications

    Indian Academy of Sciences (India)

    Subhasis Nandi

    2008-10-01

    There have been renewed interests in slip-ring induction machines due to their increasing use in both grid connected and stand-alone wind power generation schemes. Despite the squirrel cage induction generators’ advantages of being brushless, low-cost, needing less maintenance and having inherent overload protection, the biggest advantage of variable-speed wound rotor induction machines is in its doubled energy capture. Also in high power induction motor drives such as static Kramer drives or static Scherbius drives use of wound rotor induction motors is a must. Thus it becomes necessary to measure the speed of the machine for closed loop control for such high performance drives. Recently, a sensorless position and speed estimation scheme was proposed for wound rotor wind power generator. In this paper, the limitation of the scheme caused by space and time harmonics have been investigated. Simulation results have been presented to explain the mechanism of the space and time harmonics caused distortion of current. Experimental results showing the deterioration of speed detection scheme at light load for a slip-ring induction motor have been presented. Finally, improvements have been applied experimentally to obtain better speed estimation.

  15. Effects of priming exercise on the speed of adjustment of muscle oxidative metabolism at the onset of moderate-intensity step transitions in older adults.

    Science.gov (United States)

    De Roia, Gabriela; Pogliaghi, Silvia; Adami, Alessandra; Papadopoulou, Christina; Capelli, Carlo

    2012-05-15

    Aging is associated with a functional decline of the oxidative metabolism due to progressive limitations of both O(2) delivery and utilization. Priming exercise (PE) increases the speed of adjustment of oxidative metabolism during successive moderate-intensity transitions. We tested the hypothesis that such improvement is due to a better matching of O(2) delivery to utilization within the working muscles. In 21 healthy older adults (65.7 ± 5 yr), we measured contemporaneously noninvasive indexes of the overall speed of adjustment of the oxidative metabolism (i.e., pulmonary Vo(2) kinetics), of the bulk O(2) delivery (i.e., cardiac output), and of the rate of muscle deoxygenation (i.e., deoxygenated hemoglobin, HHb) during moderate-intensity step transitions, either with (ModB) or without (ModA) prior PE. The local matching of O(2) delivery to utilization was evaluated by the ΔHHb/ΔVo(2) ratio index. The overall speed of adjustment of the Vo(2) kinetics was significantly increased in ModB compared with ModA (P ModA (P < 0.05), suggesting an improved O(2) delivery. Our data are compatible with the hypothesis that, in older adults, PE, prior to moderate-intensity exercise, beneficially affects the speed of adjustment of oxidative metabolism due to an acute improvement of the local matching of O(2) delivery to utilization.

  16. Chapter 18: Variable Frequency Drive Evaluation Protocol

    Energy Technology Data Exchange (ETDEWEB)

    Romberger, J.

    2014-11-01

    An adjustable-speed drive (ASD) includes all devices that vary the speed of a rotating load, including those that vary the motor speed and linkage devices that allow constant motor speed while varying the load speed. The Variable Frequency Drive Evaluation Protocol presented here addresses evaluation issues for variable-frequency drives (VFDs) installed on commercial and industrial motor-driven centrifugal fans and pumps for which torque varies with speed. Constant torque load applications, such as those for positive displacement pumps, are not covered by this protocol. Other ASD devices, such as magnetic drive, eddy current drives, variable belt sheave drives, or direct current motor variable voltage drives, are also not addressed. The VFD is by far the most common type of ASD hardware. With VFD speed control on a centrifugal fan or pump motor, energy use follows the affinity laws, which state that the motor electricity demand is a cubic relationship to speed under ideal conditions. Therefore, if the motor runs at 75% speed, the motor demand will ideally be reduced to 42% of full load power; however, with other losses it is about 49% of full load power.

  17. Evaluation of the Ride-Through Capability of an Active-Front-End Adjustable Speed Drive under Real Grid Conditions

    DEFF Research Database (Denmark)

    Liserre, Marco; Klumpner, Christian; Blaabjerg, Frede;

    2004-01-01

    to the replacement of the electrolytic capacitors with film capacitors, which have lower energy density meaning that the volume is similar, but will increase the ASD lifetime. In these circumstances, operation under unbalanced and distorted supply voltage as well as high dynamic operation of the ASD makes...

  18. Speed anti-windup PI strategies review for field oriented control of permanent magnet synchronous machines servo drives with matrix converters

    OpenAIRE

    Espina Masramon, Jorge; Arias Pujol, Antoni; Balcells Sendra, Josep; Ortega García, Carlos; Galceran Arellano, Samuel

    2009-01-01

    When facing real systems PI tuning, the plant is modeled disregarding its physical limitations. Consequently, the PI output may increase indefinitely its value; phenomenon called Windup. This paper presents a review and a comparison between different Anti-Windup PI strategies used in speed motion and position control for Matrix Converter PMSM servo drives.

  19. A Study on Driver Posture Adjustment During Longtime Driving%长时间驾驶过程中驾驶员姿势调节的研究

    Institute of Scientific and Technical Information of China (English)

    王波; 成波; 张非若; 陶鑫

    2014-01-01

    The effects of posture adjustment, including seat cushion adjustment and backrest adjustment, during longtime driving are studied in this paper. Specifically, the effects of the direction, amplitude and frequency of adjustment are studied by comprehensively adopting the testing means of body pressure distribution and subjective rating method. The results of seat cushion and backrest adjustment experiments indicate that the forward adjustment of seat cushion can significantly enhance driving comfort, especially the comforts of hands and legs;while the back-ward one has no apparent effects. The forward adjustment of backrest can also improve the comfort of overall human body except hip;while the backward one has little effects. As for the amplitude and frequency of adjustment, their changes on the effects of both seat cushion and backrest adjustments are not significant.%本文研究了在长时间驾驶过程中进行姿势调节(包括坐垫调节和靠背调节)的效果,综合采用了体压分布测试手段和主观评价方法,研究了调节方向、调节幅度和调节频度的影响。坐垫调节实验和靠背调节实验的结果表明,向前调整坐垫能显著提高驾乘舒适性,尤其是手臂、下肢等末端的舒适性;向后调整坐垫效果不明显。向前调整靠背能够在整体上提高人体舒适性,但是臀部的舒适性会下降;向后调整靠背效果不大。就本文中选取的调节幅度和频度,对坐垫调节效果和靠背调节效果没有显著的影响。

  20. The Adjustment of AD Speed Command Range of Motor Controller%电机控制器的AD速度指令范围调整

    Institute of Scientific and Technical Information of China (English)

    张松松; 卢刚; 李声晋; 周勇

    2012-01-01

    The data communication between host computer and brushless DC motor controller base on TMS320F28335 were researched and achieved, and the adjustment of AD speed command range was realized. The PC monitoring platform was programmed by the CVI8.5 language. The adjustment procedures of AD speed command rang was written by the C language , which was correspond to the PC monitoring platform. The experimental results validated the data communication between host computer and motor controller, and the adjustment of AD speed command range.%研究实现了基于TMS320F28335控制的无刷直流电动机控制器与上位机之间的数据通讯,并在此基础上实现了AD速度指令范围调整功能.用CV18.5编写了上位机监控平台,C语言编写了与之对应的AD速度指令范围调整程序,实验结果验证了上位机与电机控制器之间的数据通讯和AD速度指令范围调整功能.

  1. Fuzzy Logic based Speed Control of a Six-Phase Series-Connected Two-Motor Drive System Feed from SVPWMVSI

    Directory of Open Access Journals (Sweden)

    H. A. Hairik

    2008-01-01

    Full Text Available This paper presents a new topology for the control of a six-phase series-connectedtwo-motor drive system supplied from Space Vector Pulse Width Modulation (SVPWMVoltage Source Inverter (VSI. The two-motordrive system consists of a six-phase and athree-phase induction motors connected in series. These motors and the supply system havebeen analyzed to construct a field-orientedmodel for them. This model clearly shows thepossibility of independent of control of the two machines. A fuzzy logic based speed controller has been constructed and used to drive the two-motor in this work . The two-motor system, inverter system, and the fuzzy controller models are implemented and tested using Simulink/Matlab facilities. The presented results show the validity of the model to dowell for the sake of speed control under different operating conditions.

  2. EC technology for blower drives. Maximum efficiency across the whole speed range; EC-Technik fuer Ventilator- und Geblaeseantriebe. Hoechste Wirkungsgrade im gesamten Drehzahlbereich

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, T. [ebm-papst Mulfingen GmbH und Co. KG, Mulfingen (Germany)

    2006-03-15

    Blowers are often powered by rotary-current asynchronous motors with short-circuit rotors, which are robust, simple and reliable. Today, specifications have become more demanding. For example, economic efficiency and low noise - combined with speed control which again should be as simple as possible - are now required. Asynchronous motors are hardly capable of meeting these requirements, so they are being replaced in many applications by electronically commuted permanent magnet motors, so-called EC drives. (orig.)

  3. A DSP-based modified slip energy recovery drive using a 12-pulse converter and shunt chopper for a speed control system of a wound rotor induction motor

    Energy Technology Data Exchange (ETDEWEB)

    Tunyasrirut, Satean; Ngamwiwit, Jongkol [Faculty of Engineering and Research Center for Communications and Information Technology, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand); Kinnares, Vijit [Department of Electrical Engineering, Faculty of Engineering, King Mongkut' s Institute of Technology Ladkrabang, Bangkok 10520 (Thailand); Furuya, Tadayoshi [Department of Electronics and Control Engineering, Kitakyushu National College of Technology, Kitakyushu, Fukuoka (Japan); Yamamoto, Yoshiichi [Department of Electronic Control, Kumamoto National College of Technology, 2659-2 Suya Nishigoshi-machi Kikuchi-Gun, Kumamoto Prefecture 861-1102 (Japan)

    2008-05-15

    This paper introduces a modified slip energy recovery drive system for speed control of a wound rotor induction motor offering improvement of drive performance, particularly line power factor and overall system efficiency. A 12-pulse line commutated thyristor converter operating in an inverter mode in conjunction with an additional IGBT shunt chopper is employed to transfer slip energy back to ac mains supply via three phase transformers. This approach offers motor speed control by varying the duty cycle of the chopper instead of changing the inverter firing angle. As a consequence, supply power factor can be improved. The servo state feedback designed by linear quadratic regulator (LQR) with observer is also included in order to keep motor speed to be constant over a certain range of operating conditions by using the estimated dc link current derived from motor speed. The advantage of this technique is absence of current transducers for current feedback control loop. The overall control system is implemented on DSP, DS1104'TMS320F240 controller board. Experimental results are illustrated in order to validate performance of the proposed system. (author)

  4. Fault Tolerant Three-Phase AC Motor Drive Topologies:A Comparison of Features, Cost, and Limitations

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    THE RELIABILITY of adjustables peed ac motor drives is an area of great interest for all members of the drives community and marketplace. This is particularly the case for the military, aerospace and automotive industries that are increasingly adopting variable speed drives in order to improve overall system efficiency and performance. There are certain safety critical applications such as steering, fuel pumps,

  5. DAC to Mitigate the Effect of Periodic Disturbances on Drive Train using Collective Pitch for Variable Speed Wind Turbine

    DEFF Research Database (Denmark)

    Imran, Raja Muhammad; Hussain, Dil Muhammad Akbar; Soltani, Mohsen

    2015-01-01

    DAC is a linear control technique used to mitigate the effect of disturbance on the plant. It is a superposition of full state feedback and disturbance feedback. This paper presents a control technique based on Disturbance Accommodation Control (DAC) to reduce fatigue on drive train generated by ...

  6. Common-mode DC-bus filter design for variable-speed drive system via transfer ratio measurements

    NARCIS (Netherlands)

    Zhao, D.; Ferreira, J.A.; Roc'h, A.; Leferink, F.

    2009-01-01

    Filters used in electromagnetic interference suppression are often described in literature on drive systems and have become a standard solution in industry. The effect of the commercial off-the-shelf filter depends significantly on how it is installed. A model that includes the installation paramete

  7. Sensorless FOC Performance Improved with On-Line Speed and Rotor Resistance Estimator Based on an Artificial Neural Network for an Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    Jose. M. Gutierrez-Villalobos

    2015-06-01

    Full Text Available Three-phase induction motor drive requires high accuracy in high performance processes in industrial applications. Field oriented control, which is one of the most employed control schemes for induction motors, bases its function on the electrical parameter estimation coming from the motor. These parameters make an electrical machine driver work improperly, since these electrical parameter values change at low speeds, temperature changes, and especially with load and duty changes. The focus of this paper is the real-time and on-line electrical parameters with a CMAC-ADALINE block added in the standard FOC scheme to improve the IM driver performance and endure the driver and the induction motor lifetime. Two kinds of neural network structures are used; one to estimate rotor speed and the other one to estimate rotor resistance of an induction motor.

  8. Sensorless FOC Performance Improved with On-Line Speed and Rotor Resistance Estimator Based on an Artificial Neural Network for an Induction Motor Drive.

    Science.gov (United States)

    Gutierrez-Villalobos, Jose M; Rodriguez-Resendiz, Juvenal; Rivas-Araiza, Edgar A; Martínez-Hernández, Moisés A

    2015-06-29

    Three-phase induction motor drive requires high accuracy in high performance processes in industrial applications. Field oriented control, which is one of the most employed control schemes for induction motors, bases its function on the electrical parameter estimation coming from the motor. These parameters make an electrical machine driver work improperly, since these electrical parameter values change at low speeds, temperature changes, and especially with load and duty changes. The focus of this paper is the real-time and on-line electrical parameters with a CMAC-ADALINE block added in the standard FOC scheme to improve the IM driver performance and endure the driver and the induction motor lifetime. Two kinds of neural network structures are used; one to estimate rotor speed and the other one to estimate rotor resistance of an induction motor.

  9. DSP-based adaptive backstepping using the tracking errors for high-performance sensorless speed control of induction motor drive.

    Science.gov (United States)

    Zaafouri, Abderrahmen; Ben Regaya, Chiheb; Ben Azza, Hechmi; Châari, Abdelkader

    2016-01-01

    This paper presents a modified structure of the backstepping nonlinear control of the induction motor (IM) fitted with an adaptive backstepping speed observer. The control design is based on the backstepping technique complemented by the introduction of integral tracking errors action to improve its robustness. Unlike other research performed on backstepping control with integral action, the control law developed in this paper does not propose the increase of the number of system state so as not increase the complexity of differential equations resolution. The digital simulation and experimental results show the effectiveness of the proposed control compared to the conventional PI control. The results analysis shows the characteristic robustness of the adaptive control to disturbances of the load, the speed variation and low speed.

  10. Energy efficiency by means of speed regulated drives with frequency converters; Energieeffizienz durch drehzahlgeregelte Antriebe mit Frequenzumformern

    Energy Technology Data Exchange (ETDEWEB)

    Ristimaeki, Tomi [Centraline c/o Honeywell GmbH, Schoenaich (Germany)

    2009-12-15

    Due to continuously increasing energy prices, companies ever more frequently are compelled to energy conservation and cost savings. The use of frequency converters for speed regulation of turbomachines such as pumps, fans and compressors is not a new idea. The new technologies within this range make this alternative still more attractive due to the smaller costs. The use of electric motors with variable speed regulation in HLK systems offers a large potential for energy conservation. This technology makes a substantial contribution to the adherence of local and international agreements and standards in the range of the energy-saving policy and the lowering of the CO{sub 2} emissions.

  11. Fault Detection in Gear Drives with Non-Stationary Rotational Speed - Part II: the Time-Quefrency Approach

    Science.gov (United States)

    Meltzer, G.; Ivanov, Yu. Ye.

    2003-03-01

    This paper deals with the recognition of faults in toothing during non-stationary start up and run down of gear drives. In the first part, this task was solved by means of the time-frequency analysis. A planetary gear was used as a case study. Part II contains a new approach using the time-quefrency analysis. The same example was successfully subjected in this procedure.

  12. Applied intelligent control of induction motor drives

    CERN Document Server

    Chan, Tze Fun

    2011-01-01

    Induction motors are the most important workhorses in industry. They are mostly used as constant-speed drives when fed from a voltage source of fixed frequency. Advent of advanced power electronic converters and powerful digital signal processors, however, has made possible the development of high performance, adjustable speed AC motor drives.This book aims to explore new areas of induction motor control based on artificial intelligence (AI) techniques in order to make the controller less sensitive to parameter changes. Selected AI techniques are applied for different induction motor control s.

  13. A semelparous fish continues upstream migration when exposed to alarm cue, but adjusts movement speed and timing

    Science.gov (United States)

    Luhring, Thomas M; Meckley, Trevor D.; Johnson, Nicholas S.; Siefkes, Michael J.; Hume, John B.; Wagner, C. Michael

    2016-01-01

    Animals make trade-offs between predation risk and pursuit of opportunities such as foraging and reproduction. Trade-offs between antipredator behaviours and foraging are well suited to manipulation in laboratory and field settings and have generated a vast compendium of knowledge. However, much less is known about how animals manage trade-offs between predation risk and pursuit of reproductive opportunities in the absence of the confounding effects of foraging. In the present study, we investigated how the nonfeeding migratory life stage of sea lamprey, Petromyzon marinus, responds to odour from dead conspecifics (a cue that induces avoidance behaviours in laboratory and field studies). We released groups of PIT-tagged sea lamprey 65 m from the shore of Lake Michigan or 287 m upstream in Carp Lake River and used antennas to detect their movements in the river. As the breeding season progressed, sea lamprey initiated upstream movement earlier and were more likely to enter the river. Sea lamprey that began the night in Lake Michigan entered Carp Lake River at higher rates and accelerated upstream when exposed to high concentrations of alarm cue, consistent with animals attempting to minimize time spent in risky areas. Sea lampreys that began the night in the river delayed upstream movement when exposed to alarm cue, consistent with animals sheltering and gathering information about a source of risk. We attribute this context-specific reaction to alarm cue to differences in perceived vulnerability to predation in sheltered positions in the river versus exposed positions in the lake. Once in the river, the vast majority of sea lamprey moved upstream independent of alarm cue or Julian date. Although life-history-induced time and energy budgets place rigid constraints on the direction of migration, sea lamprey attend to predation risk by modifying movement timing and speed.

  14. THE ANALYSIS OF MATHEMATICAL MODELS OF MECHANICAL SPEED OF DRIVING FOR OPTIMIZATION OF PROCESS OF DRILLING OF OIL AND GAS WELLS

    Directory of Open Access Journals (Sweden)

    Tsоuprikov A. A.

    2015-03-01

    Full Text Available The analysis of models is carried out from a definition position for system of optimum control of drilling of basic mathematical model on which calculation of optimum regime parameters is possible. The main equation for management of process of drilling of wells is the mathematical model of mechanical speed of a driving as function from axial load of a chisel, the speed of rotation of a chisel and a consumption of boring solution for cleaning of a well of destroyed breed. Key parameter is axial load of a chisel; graphically dependence of speed of drilling on loading has S appearance - a figurative curve of Bingham which has a convex mathematical extremum. In the article, domestic and foreign models of drilling are considered; their schedules according to skilled data of conducting of wells are constructed. Models are sedate, i.e. reflect only a linear site of a curve of Bingham, data of trade drilling is well approximated with initial and linear sites of curves. Thus, on them it is possible to make only rational management of process, and the optimum mode exists only on border of range of definition of function. Only the A.A. Pogarsky model is suitable for optimum control, having a mathematical maximum and S-shaped form of a curve. All models depend on two parameters of management – load of a chisel and speeds of rotation of a chisel and don't consider the third on influence on drilling speed parameter - a consumption of boring solution. Therefore, Pogarsky's model was finished by inclusion in it in an explicit form of a consumption of boring solution. Check of model by means of the regression analysis of skilled data of drilling from official reports of drilling foremen showed its reliability for 71-99%. The model allows carrying out optimum control of drilling in the "axial load of a chisel" parameter

  15. Correlation of prefrontal cortical activation with changing vehicle speeds in actual driving: a vector-based functional near-infrared spectroscopy study

    Directory of Open Access Journals (Sweden)

    Kayoko eYoshino

    2013-12-01

    Full Text Available Traffic accidents occur more frequently during deceleration than during acceleration. However, little is known about the relationship between brain activation and vehicle acceleration because it has been difficult to measure the brain activation of drivers while they drive. In this study, we measured brain activation during actual driving using vector-based functional near-infrared spectroscopy. Subjects decelerated from 100 to 50 km/h (speed reduction task and accelerated from 50 to 100 km/h (speed increase task while driving on an expressway, in the daytime and at night. We examined correlations between average vehicle acceleration in each task and five hemodynamic indices: changes in oxygenated hemoglobin (ΔoxyHb, deoxygenated hemoglobin (ΔdeoxyHb, cerebral blood volume (ΔCBV, and cerebral oxygen exchange (ΔCOE; and the phase angle k (degrees derived from the other hemoglobin (Hb indices. ΔoxyHb and ΔCBV reflect changes in cerebral blood flow, whereas ΔdeoxyHb, ΔCOE, and k are related to variations in cerebral oxygen metabolism. Most of the resulting correlations with specific brain sites, for all the indices, appeared during deceleration rather than during acceleration. Faster deceleration resulted in greater increases in ΔdeoxyHb, ΔCOE, and k in the prefrontal cortex (r 0.4, p < 0.01, suggesting oxygen metabolism associated with transient ischemic changes. Our results suggest that vehicle deceleration requires more brain activation, focused in the prefrontal cortex, than does acceleration. From the standpoint of the indices used, we found that simultaneous analysis of multiple hemodynamic indices was able to detect not only the blood flow components of hemodynamic responses, but also more localized frontal lobe activation involving oxygen metabolism.

  16. Scenario analysis of carbon emissions' anti-driving effect on Qingdao's energy structure adjustment with an optimization model, Part II: Energy system planning and management.

    Science.gov (United States)

    Wu, C B; Huang, G H; Liu, Z P; Zhen, J L; Yin, J G

    2017-03-01

    In this study, an inexact multistage stochastic mixed-integer programming (IMSMP) method was developed for supporting regional-scale energy system planning (EPS) associated with multiple uncertainties presented as discrete intervals, probability distributions and their combinations. An IMSMP-based energy system planning (IMSMP-ESP) model was formulated for Qingdao to demonstrate its applicability. Solutions which can provide optimal patterns of energy resources generation, conversion, transmission, allocation and facility capacity expansion schemes have been obtained. The results can help local decision makers generate cost-effective energy system management schemes and gain a comprehensive tradeoff between economic objectives and environmental requirements. Moreover, taking the CO2 emissions scenarios mentioned in Part I into consideration, the anti-driving effect of carbon emissions on energy structure adjustment was studied based on the developed model and scenario analysis. Several suggestions can be concluded from the results: (a) to ensure the smooth realization of low-carbon and sustainable development, appropriate price control and fiscal subsidy on high-cost energy resources should be considered by the decision-makers; (b) compared with coal, natural gas utilization should be strongly encouraged in order to insure that Qingdao could reach the carbon discharges peak value in 2020; (c) to guarantee Qingdao's power supply security in the future, the construction of new power plants should be emphasised instead of enhancing the transmission capacity of grid infrastructure.

  17. 基于dSPACE的高速列车牵引传动系统%Drive system based on dSPACE platform for high-speed train

    Institute of Scientific and Technical Information of China (English)

    葛兴来; 宋文胜; 冯晓云

    2012-01-01

    The variable-frequency speed regulation based on rotor flux control for the traction inverter-motor system with three-level diode NPC (Neutral-Point-Clamped) topology is analyzed covering whole speed range of high-speed train. The functional block of rotor-flux-oriented indirect vector control is given and its implementation algorithm is discussed in detail. The compensation algorithm for the precise modeling of the main circuit of three-level traction drive is presented,which considers the effect of dead-time and PWM sampling error. Its simulation model is built based on the hardware-in-the-loop real-time simulation platform of dSPACE and the traction drive control algorithm is programmed based on TMS320F2812 DSP. The comparison of control performance among different main circuit realization methods and among different calculation steps demonstrates the validity of the real-time simulation modeling algorithm and the drive control algorithm.%针对高速列车二极管中点箝位三电平拓扑牵引逆变器-牵引电机系统运行控制的要求,对牵引电机运行全速度范围中基于转子磁通控制的变频调速控制方式进行了分析,给出了转子磁场定向间接矢量控制功能框图并对实现算法进行了详细阐述.考虑死区效应和PWM采样误差的影响提出了三电平牵引传动主电路精确建模的补偿算法,建立了基于dSPACE半实物仿真平台的牵引传动主电路实时仿真模型,根据上述理论分析编制了基于TMS320F2812型DSP的牵引传动控制实现算法.对该控制算法在不同的主电路模型实现算法和不同计算步长下的实时仿真实验结果进行了对比分析,结果验证了该牵引传动主电路实时仿真建模算法和传动控制算法的有效性.

  18. Performance Parameter Calculation of Adjustable Speed Asynchronous Disk Magnetic Coupling%可调速异步盘式磁力联轴器性能参数计算

    Institute of Scientific and Technical Information of China (English)

    杨超君; 郑武; 李直腾; 李志宝; 蒋生发

    2011-01-01

    提出一种具有新型结构的可调速异步盘式磁力联轴器,其从动盘导体采用深槽齿形结构,通过主从动盘之间的气隙长度的变化来改变磁场强度,从而实现速度的调节.该联轴器可应用在一些大转矩、大振动的机械装备中以避免振动,或实现电机在负载时的软启动.对该磁力联轴器结构与主磁路特点进行了分析,对一台9对极16槽的深槽式异步磁力联轴器进行三维静态、瞬态有限元模拟分析,获得了该磁力联轴器的磁场分布、电流分布情况;并对其转矩、功率损耗以及轴向力等性能参数进行计算,得出它们在瞬态情况下随时间变化的曲线.%A novel adjustable speed asynchronous disk magnetic coupling was proposed,of which conductor on driven plate adopted a deep slot teeth shape structure. While the length of air gap between drive and driven plate is changed, the strength of magnetic field is increased or reduced accordingly, then its run speed adjustment is available. It can be used in some high pulling torque and excess vibration of mechanical equipment to avoid vibration, or also realize the motor soft start when in load.Its configuration characteristics and main magnetic circuit characteristics were discussed herein and a deep slot asynchronous magnetic coupling with 9 pole-pairs and 16 slots was analyzed by three-dimensional FEM under static and transient state, the distribution of magnetic field and current were obtained. The performance parameters of the new coupling including torque, power loss and axial force were calculated, and their corresponding curves in the transient conditions were obtained.

  19. Associations between driving under the influence of alcohol or drugs, speeding and seatbelt use among fatally injured car drivers in Norway.

    Science.gov (United States)

    Bogstrand, Stig Tore; Larsson, Magnus; Holtan, Anders; Staff, Trine; Vindenes, Vigdis; Gjerde, Hallvard

    2015-05-01

    Since 2005, all fatal road traffic crashes in Norway have been analyzed in-depth by multidisciplinary investigation teams organized by the Norwegian Public Roads Administration (NPRA). During the period 2005-2010, 608 drivers of cars or vans were killed in road traffic crashes. Blood samples were collected from 372 (61%) of the drivers and analyzed for alcohol and a large number of psychoactive drugs at the Norwegian Institute of Public Health (NIPH). After coupling the analytical results with the NPRA crash database, 369 drivers with a fatal outcome were identified and included. Alcohol or drug concentrations in blood above the legal limits were found in 39.8% of the drivers who were investigated for alcohol or drug impairment; 33.9% had blood alcohol concentrations above 0.5g/L or concentrations of drugs above the equivalent Norwegian legal impairment limits or concentrations of amphetamines above 200μg/L. Among drivers with a fatal outcome who had been impaired by alcohol or drugs, 64.6% were unbelted and 71.7% were speeding when the crash occurred; whereas 24.2% and 33.2% of the sober drivers were unbelted or speeding, respectively. Statistically significant associations were found between impairment by alcohol or amphetamines and driving unbelted or speeding. Excessive speeding is one of the main reasons for road traffic crashes and together with being unbelted the main reasons for a fatal outcome. This behavior might in many cases be due to increased risk-taking or negligence of safety measures as a result of alcohol or drug use.

  20. Extending the Linear Modulation Range to the Full Base Speed Using a Single DC-Link Multilevel Inverter With Capacitor-Fed H-Bridges for IM Drives

    DEFF Research Database (Denmark)

    Rahul, Arun; Pramanick, Sumit; Kaarthik, R. Sudharshan

    2017-01-01

    of the inverter can be increased from 0.577 to 0.637Vdc without increasing the dc bus voltage and without exceeding the induction motor voltage rating. This new technique makes use of cascaded inverter pole voltage redundancy and property of the space vector structure for its operation. Using this, the induction......In this paper, a new space vector pulse width modulation method to extend the linear modulation range of a cascaded five level inverter topology with a single dc supply is presented. Using this method, the inverter can be controlled linearly and the peak phase fundamental output voltage...... motor drive can be operated till the full speed range (0-50 Hz) with the elimination of lower order harmonics in the phase voltage and phase current. The five-level topology presented in this paper is realized by cascading a two-level inverter and two full bridge modules with floating capacitors...

  1. Comparative study of SVPWM (space vector pulse width modulation) & SPWM (sinusoidal pulse width modulation) based three phase voltage source inverters for variable speed drive

    Science.gov (United States)

    Ahmed, Waheed; Usman Ali, Syed M.

    2013-12-01

    We have performed comparative studies of Space Vector Pulse Width Modulation (SVPWM) and Sinusoidal Pulse Width Modulation (SPWM) techniques utilizing MATLAB tools. During these investigations, we carried out intensive simulations, comprehensively analyzed the obtained results and compared the harmonic density, power factor (PF), & switching losses of SVPWM and SPWM. It has been observed during investigations that if the switching frequency is high then losses due to harmonics are negligible, thus based on obtained results we suggested that the SVPWM technique is a more reliable solution. Because SVPWM utilizes DC bus voltage more efficiently, generates less Total Harmonic Distortion (THD) and has higher output quality it provides flexible control of output voltage and output frequency for Variable Speed Drive (VSD).

  2. Neural Network Based Fault Detection and Diagnosis System for Three-Phase Inverter in Variable Speed Drive with Induction Motor

    Directory of Open Access Journals (Sweden)

    Furqan Asghar

    2016-01-01

    Full Text Available Recently, electrical drives generally associate inverter and induction machine. Therefore, inverter must be taken into consideration along with induction motor in order to provide a relevant and efficient diagnosis of these systems. Various faults in inverter may influence the system operation by unexpected maintenance, which increases the cost factor and reduces overall efficiency. In this paper, fault detection and diagnosis based on features extraction and neural network technique for three-phase inverter is presented. Basic purpose of this fault detection and diagnosis system is to detect single or multiple faults efficiently. Several features are extracted from the Clarke transformed output current and used in neural network as input for fault detection and diagnosis. Hence, some simulation study as well as hardware implementation and experimentation is carried out to verify the feasibility of the proposed scheme. Results show that the designed system not only detects faults easily, but also can effectively differentiate between multiple faults. These results prove the credibility and show the satisfactory performance of designed system. Results prove the supremacy of designed system over previous feature extraction fault systems as it can detect and diagnose faults in a single cycle as compared to previous multicycles detection with high accuracy.

  3. Comparative Analysis of Different PWM Techniques to Reduce the Common Mode Voltage in Three-Level Neutral-Point-Clamped Inverters for Variable Speed Induction Drives

    Directory of Open Access Journals (Sweden)

    Bharati Raja

    2012-12-01

    Full Text Available This work presents the comparative study of the different PWM techniques to reduce the common-mode voltage (CMV at the output of neutral point diode clamped inverter for variable speed drives. Here the comparative study is done by the phase opposition disposed (POD, sinusoidal pulse width modulation (SPWM, phase disposition (PD, phase shift (PS space vector modulation (SVM techniques are proposed. A good trade-off between the quality of the output voltage and the partial magnitude of the CMV is achieved in this work. The scheme is proposed for three-level inverter. This work realizes the implementation of Three-level diode clamped MLI for three-phase (Y-Δ induction motor with the implementation of a space vector modulation technique without any additional control algorithm to reduce CMV within the range + Vdc/6. The Simulation with a 1HP induction motor drive system is setup in Matlab-2011b  and the same results validated effectively by hardware – FPGA-SPARTEN III processor and its shows that the CM voltage is effectively reduced and the maximum output voltage is not affected.  

  4. Spindle picker harvest speed effects

    Science.gov (United States)

    The gear drive of a modern John Deere Pro 16 picker unit was modified so that spindle speed was reduced without changing the drum speed. Three 1-row picking units were used in the study, one with the standard drive speeds, one with 25% reduction in spindle drive speed, and one with 50% reduction in...

  5. Influence of a helicopter's maneuvering flight on critical speed of its tail drive shaft%直升机机动飞行对尾传动轴临界转速的影响

    Institute of Scientific and Technical Information of China (English)

    陆凤霞; 朱如鹏; 倪德

    2016-01-01

    All translational motion components of a helicopter and position parameters of its tail drive shaft do not affect critical speeds of its tail drive shaft,and only rotating motion components of the helicopter affect critical speeds of its tail drive shaft.The influences of rotating motion components of a helicopter on critical speeds of its tail drive shaft were analyzed.The results showed that the yaw angular velocity versus the critical speed of the horizontal drive shaft reveals a relation of parabola,while the yaw angular velocity versus the critical speed of the oblique tail drive shaft is a linear relation and the relation curve is symmetrical;the symmetry axis offsets to the left with increase in the inclination angle of the oblique tail drive shaft;the influence of the pitching angular velocity on critical speeds of the tail drive shaft is the same as that of the yaw angular velocity;the relations'between the rolling angular velocity and critical speeds of the horizontal drive shaft and the oblique tail drive shaft are a linear relation,and the symmetry axis offsets to the right with increase in the inclination angle of the oblique tail drive shaft;the angular velocity corresponding to the symmetric axis of the second-order critical speed curve of the drive shaft is about 16 times of the first-order critical speed.%直升机的平动分量和尾传动轴的位置参数均不影响传动轴的临界转速,仅直升机的转动分量对传动轴临界转速产生影响。通过几种典型机动飞行分析了直升机各转动分量对尾传动轴临界转速的影响。结果表明:偏航角速度与水平轴的临界转速近似呈抛物线关系,而与尾斜轴的临界转速近似呈线性关系且为左右对称图形;随着尾斜轴倾斜角的增大,对称轴向左偏移;俯仰角速度对尾传动轴临界转速的影响与偏航角速度相同;横滚角速度与水平轴和尾斜轴临界转速之间均呈线性关系,且随尾斜轴

  6. 可调式风扇传动安装座在客车上的应用%Application of an Adjustable Fan Drive Installed Stand to Bus/Coach

    Institute of Scientific and Technical Information of China (English)

    叶成友

    2015-01-01

    针对目前客车上采用传统风扇传动装置存在皮带异常磨损和断裂的问题,介绍一种可调式风扇传动安装座的解决方案,彻底解决风扇传动皮带异常磨损和断裂的问题,延长使用寿命和降低维护保养成本。%Aiming at the abnormal wear and fracture problems of the belts with traditional fan drive equipment on a bus/coach, the author introduces a type of a solution of adjustable fan drive installation stand. This can completely solve the problem of fan drive belts abnormal wear and fracture, prolong the service life and reduce the maintenance cost.

  7. Police Enforcement Policy and Programmes on European Roads (PEPPER). Deliverable 9: Good practice in the selected key areas : speeding, drink driving and seat belt wearing : results from meta-analysis.

    NARCIS (Netherlands)

    Erke, A. Goldenbeld, C. & Vaa, T.

    2009-01-01

    The main objective of task 4.2 in the EU-project PEPPER on traffic law enforcement measures has been to give a systematic review of evaluation studies on speed, drink driving and seat-belt enforcement by applying meta-analyses to assess the best estimates of the effects of enforcement measures on ac

  8. Police Enforcement Policy and Programmes on European Roads (PEPPER). Deliverable 9: Good practice in the selected key areas : speeding, drink driving and seat belt wearing : results from meta-analysis.

    NARCIS (Netherlands)

    Erke, A. Goldenbeld, C. & Vaa, T.

    2008-01-01

    The main objective of task 4.2 in the EU-project PEPPER on traffic law enforcement measures has been to give a systematic review of evaluation studies on speed, drink driving and seat-belt enforcement by applying meta-analyses to assess the best estimates of the effects of enforcement measures on ac

  9. SPEED CONTROL OF DC MOTOR WITH PIC 16F877

    OpenAIRE

    ÇOLAK, İlhami; Ramazan BAYINDIR

    2005-01-01

    In this study, a PI controlled separately excited direct current (DC) motor speed has been controlled using PIC 16F877 controller. In the PIC 16F877 programming as a PI controller, the speed of the motor is expected to follow the reference speed. Speed of the motor is measured by a tacho generator and then, the voltage applied to the motor is adjusted by a semiconductor power switch using pulse width modulation (PWM) technique. Drive circuit was tested with 0.9 kW DC motor. Experimental resul...

  10. Improved Control of an Active-Front-End Adjustable Speed Drive with a Small dc-link Capacitor under Real Grid Conditions

    DEFF Research Database (Denmark)

    Klumpner, Christian; Liserre, Marco; Blaabjerg, Frede

    2004-01-01

    capacitors will be replaced by film capacitors in order to increase the ASD lifetime, but as this has lower energy density, the dc-link capacitance is expected to decrease. In these circumstances, operation under unbalanced and distorted supply voltage as well as high dynamic operation of the ASD makes...... severe due to the small dc-link storage. To mitigate the latter problem it is proposed to pre-compensate the dc-link voltage reference signal considering the real grid voltage. Experiments show that the system handles successfully unbalance situation even with a small dc-link capacitor....

  11. Measures for speed management.

    NARCIS (Netherlands)

    2009-01-01

    Measures for speed management are essential for limiting the negative effects of driving too fast and at inappropriate speeds. To begin with, safe and credible speed limits need to be determined. Dynamic and variable speed limits that take into account the current circumstances, such as weather cond

  12. Pressure-velocity model and speed adjustment strategy for in-pipe detector in gas pipeline%输气管道内检测器压力-速度模型及速度调整策略

    Institute of Scientific and Technical Information of China (English)

    杨理践; 赵洋; 高松巍

    2012-01-01

    The operation speed of in-pipeline detector will affect the accuracy of the data detection during non-destructive testing of gas pipeline. So speed regulation problem of in-pipeline detector is studied in this paper. The speed regulation of in-pipeline detector can be seen as the speed change under different steady states. In this paper, the in-pipeline detector and up-down stream gas are regarded as a whole. According to the principles of fluid mechanics, the relationship between the pipeline pressure and speed of in-pipeline detector is analyzed under stable state; and the pressure-speed model of in-pipeline detector is built. The speed of in-pipeline detector is calculated under different steady states based on the pressure-speed model, which is used as the basis of speed adjustment of in-pipeline detector. The results of simulation operation in the Second Pipeline of West-East natural gas pipeline show that the speed of in-pipeline detector can be accurately calculated and effectively adjusted with the proposed model.%内检测器的运行速度在输气管道无损检测过程中会影响数据检测的精度.针对内检测器运行速度调节问题进行研究,内检测器速度调节可以看作不同稳态条件下速度的变化.将漏磁内检测器与上下游气体视为一个整体,并根据流体力学原理分析了平稳状态下管道压力与内检测器运行速度之间的关系,建立了内检测器的压力-速度模型.通过所建立的压力-速度模型,计算出管道不同稳态条件下的内检测器速度,并以此作为内检测器速度调节的依据.通过在西气东输二线管道模拟运行表明该模型可以准确地计算出内检测器的运行速度并可以有效的进行速度调节.

  13. A driving pulse edge modulation technique and its complex programming logic devices implementation

    Institute of Scientific and Technical Information of China (English)

    Xiao CHEN; Dong-chang QU; Yong GUO; Guo-zhu CHEN

    2015-01-01

    With the continual increase in switching speed and rating of power semiconductors, the switching voltage spike becomes a serious problem. This paper describes a new technique of driving pulse edge modulation for insulated gate bipolar transistors (IGBTs). By modulating the density and width of the pulse trains, without regulating the hardware circuit, the slope of the gate driving voltage is controlled to change the switching speed. This technique is used in the driving circuit based on complex programmable logic devices (CPLDs), and the switching voltage spike of IGBTs can be restrained through software, which is easier and more flexible to adjust. Experimental results demonstrate the effectiveness and practicability of the proposed method.

  14. Research on Fine-adjusting Optimization Technology of Ballastless Turnout on High Speed Railway%高速铁路无砟道岔精调优化技术

    Institute of Scientific and Technical Information of China (English)

    谭社会

    2016-01-01

    无砟道岔精调是无砟轨道精调的重要内容,也是保证高速铁路高平顺性、高舒适性的前提。无砟道岔结构复杂,其精调与一般的轨道精调有很多不同之处。本文针对目前无砟道岔精调作业中的不足,从测量模式、精调流程等方面进行了优化,完善了作业流程控制机制和质量校核机制。通过对杭甬、杭长高速铁路无砟道岔动态检测数据的对比分析,评价精调优化的实施效果。结果表明,采用优化后的精调方法使道岔高低、轨距不平顺幅值分别降低了40%,50%,全线道岔轨道质量指数( TQI )降低了20.3%,精调优化效果显著。%As an important part of ballastless track fine-adjusting,ballastless turnout fine-adjusting provides the premise for high ride comfort and high security of high speed railway. Due to the complex structure of ballastless turnout,there are many differences between ballastless turnout fine-adjusting and normal track fine-adjusting. According to shortcomings of existing fine-adjusting,optimization was carried out from the aspects of measurement mode and fine-adjusting process,and operation process control mechanism and quality check mechanism were improved. T hrough the comparative analysis of ballastless turnout dynamic test data obtained from Hangzhou -Ningbo and Hangzhou -Changsha high speed railway,the effect of fine-adjusting optimization was evaluated. Results showed that fine-adjusting method after optimization makes the turnout height and gauge irregularity amplitude be reduced by 40% and 50% respectively and the track quality index( T QI) be reduced by 20. 3%,which indicated the optimization effect of fine-adjusting was remarkable.

  15. Improving homogeneity by dynamic speed limit systems.

    NARCIS (Netherlands)

    Nes, N. van Brandenberg, S. & Twisk, D.A.M.

    2010-01-01

    Homogeneity of driving speeds is an important variable in determining road safety; more homogeneous driving speeds increase road safety. This study investigates the effect of introducing dynamic speed limit systems on homogeneity of driving speeds. A total of 46 subjects twice drove a route along 12

  16. 单向驱动非圆齿轮差动轮系实现可调摆幅输出的研究%Study on Realizing of Adjustable Swing Output with Unidirectional Drive Non-circular Differential Gear Train

    Institute of Scientific and Technical Information of China (English)

    孙以涛; 王生泽

    2013-01-01

    A method of noncircular gear-circular gear differential gear train with unidirectional drive that could realize adjustable swing output is proposed,the condition that non-circular isn't concave is discussed,and suitable non-circular pitch curve and non-circular differential gear train are designed under this condition.Through simulation analysis different swing amplitude output can be obtained by changing the unidirectional servo drive input reasonably,especially the swing center movement of the swing output,the purpose of acquiring the adjustable output swing amplitude with unidirectional servo drive can be achieved.%提出了一种单向驱动非圆齿轮——圆齿轮差动轮系实现可调摆幅输出的方案;讨论了非圆齿轮不出现凹形的条件,并在此条件下设计出合适的非圆齿轮节曲线及非圆齿轮差动轮系;通过仿真分析合理改变单向伺服驱动输入运动规律可获得不同摆动幅值的输出,尤其是摆动中心运动的摆动输出,以达到伺服电机直接单向驱动便能实现摆幅可调输出的目的.

  17. Effect of load and speed on warship power rear drive system helical gear anti-scuffing properties in thermal elasto-hydrodynamic lubrication

    Directory of Open Access Journals (Sweden)

    Yongmei Wang

    2016-12-01

    Full Text Available The key parameters which caused the scoring failure of helical gears are operating load and speed. In this study, the simulations using geometric meshing theory were carried out to investigate the effect of load and speed of warship transmission helical gear system on thermal elasto-hydrodynamic lubrication. The numerical algorithm for the analysis of three-dimensional thermal elasto-hydrodynamic lubrication used in this work has advantage that the film pressure and distributions can be calculated from Reynolds equation for all mixed lubrication regions without any specific boundary condition for the edge of solid contact region. Oil film pressure, film thickness as well as film temperature under different load and speed conditions were obtained and compared. In addition, experimental tests were conducted to determine gear surface temperature under different load and speed conditions. This work provided a guidance to understand the load- and speed-dependent thermal elasto-hydrodynamic lubrication.

  18. 不同调整路径下资本结构的调整速度比较分析——来自中国上市公司的经验证据%Comparative Research on Capital Structure Adjustment Speeds of Different Adjustment Approaches-An Empirical Study Based on Data from Chinese Listed Companies

    Institute of Scientific and Technical Information of China (English)

    白明; 任若恩

    2011-01-01

    Based on partial adjustment model, this paper identifies the method of calculating capital structure adjustment speeds of different adjustment approaches, and compares the speeds of different adjustment approaches of Chinese listed companies, including commercial credit , short-term debt , long-term debt , stock and internal retain. The main findings are as follows. External fund is the main supply for Chinese listed companies, which seems to be the reverse of Pecking Order Theory. The most effective approach is stock and the least effective one is long-term debt. The distribution of the five adjustment speeds in different industries is different due to the different operation and ownership characteristics of the leading enterprises in different industries. The companies with financial surplus mainly depend on the stock adjustment approach while the ones with financial deficit prefer debt adjustment approach.%基于部分调整模型提出了不同调整路径下资本结构调整速度的计算方法,并且从全样本、分行业以及分现金状况三个方面,测算和比较了我国上市公司通过商业信用、短期负债、长期负债、股票以及内部留存五条路径调整资本结构的调整速度.研究发现:我国上市公司主要依靠外源资金调整资本结构,最有效的外源调整路径是股票,效率最低的路径是长期负债,调整路径的选择顺序与融资优序理论相悖;行业的经营特点和行业中龙头企业的所有制性质影响各路径调整速度的分布,各行业路径调整速度的分布存在明显差异;现金充裕的企业主要依靠调整股票路径,而现金短缺的企业则主要依靠债务调整路径.

  19. Improvement of speed profile in induction motor drive using a new idea of PWM pulses generation base on artificial neural networks

    Directory of Open Access Journals (Sweden)

    hojat moayedi rad

    2012-02-01

    Full Text Available Due to simplicity and low cost, induction motors are more useful than direct current motors. Hence the control of these motors is important. The pervious methods are fitted normally for a limited speed range and could not be used for high, low and very low speeds. The voltage model is suitable for high speed because the voltage drop of stator resistance is not small in low speed. The current model is suitable for low speed because of the problems of flux saturation at high speed. This research presents a new method of PWM pulse generating in induction motors based on artificial neural networks in which, the switching pulses are generated by a multilayer feed-forward neural network that is trained by the voltage and current references. Also, for the estimation of required torque and flux information a multilayer perceptron is used. By application of this new method, there is no problem of stability at low and high speeds. The simulation results by matlab-simulink verify the proposed method in transient and steady-state operating modes.

  20. 基于MATLAB 的交流调速系统课程仿真教学研究%Simulation Teaching Research on the Course of AC Speed Adjustment System Based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    李中望

    2015-01-01

    AC speed adjustment system is applied in the modern industry more and more widely. For this kind of professional practical course, the introduction of simulation teaching is of great significance.%交流调速系统在现代化工业生产中的应用越来越多。对于此类专业实践性很强的课程,仿真化教学的引入显得意义尤其重大。

  1. 基于MATLAB的无刷直流电机调速技术研究%Study of the Speed-adjusting Technology for BLDCM based on Matlab

    Institute of Scientific and Technical Information of China (English)

    刘栋; 荣军; 曾可; 曾敏

    2013-01-01

    无刷直流电机在工农业生产中有着广泛的应用。文章主要研究了无刷直流电机PWM调速方式,建立无刷直流电机双闭环调速控制系统的数学模型,在Matlab/Simulink中进行了建模与仿真,并对仿真结果进行了分析。%Brushless DC motor is widely used in industrial and agricultural productions. The paper studies the PWM speed-regulation mode for brushless DC motor, builds up the mathematic model of double close-loop speed-regulation system for brushless DC motor, and makes modeling and simulation in Matlab/Simulink, and finally analyzes the simulation results.

  2. Short term Braking Capability during Power Interruptions for Integrated Matrix Converter-Motor Drives

    DEFF Research Database (Denmark)

    Klumpner, Christian; Blaabjerg, Frede

    2002-01-01

    The new trend in Adjustable Speed Drives (ASD) is to integrate the inverter and the motor into a single unit in order to reduce the production cost, the commissioning time and the physical size of the equipment. This last issue becomes more important, making the matrix converter topology more...

  3. A simulator study of the effects of singing on driving performance.

    Science.gov (United States)

    Hughes, Genevieve M; Rudin-Brown, Christina M; Young, Kristie L

    2013-01-01

    This study aimed to investigate how singing while driving affects driver performance. Twenty-one participants completed three trials of a simulated drive concurrently while performing a peripheral detection task (PDT); each trial was conducted either without music, with participants listening to music, or with participants singing along to music. It was hypothesised that driving performance and PDT response times would be impaired, and that driver subjective workload ratings would be higher, when participants were singing to music compared to when there was no music or when participants were listening to music. As expected, singing while driving was rated as more mentally demanding, and resulted in slower and more variable speeds, than driving without music. Listening to music was associated with the slowest speeds overall, and fewer lane excursions than the no music condition. Interestingly, both music conditions were associated with slower speed-adjusted PDT response times and significantly less deviation within the lane than was driving without music. Collectively, results suggest that singing while driving alters driving performance and impairs hazard perception while at the same time increasing subjective mental workload. However, singing while driving does not appear to affect driving performance more than simply listening to music. Further, drivers' efforts to compensate for the increased mental workload associated with singing and listening to music by slowing down appear to be insufficient, as evidenced by relative increases in PDT response times in these two conditions compared to baseline.

  4. Optimisation of a high speed rotating composite drive shaft using a genetic algorithm - Hybrid high modulus-high resistance carbon solutions

    CERN Document Server

    Montagnier, Olivier

    2011-01-01

    This study deals with the optimisation of subcritical and supercritical laminated composite drive shafts, based on a genetic algorithm. The first part focuses on the modelling of a composite drive shaft. Flexural vibrations in a simply supported composite drive shaft mounted on viscoelastic supports, including shear effects are studied. In particular, an analytic stability criterion is developed to ensure the integrity of the system. The torsional strength is then computed with the maximum stress criterion, assuming the coupling effects to be null. Torsional buckling of thin walled composite tubes is modelled using a combination between laminate theory and Fl\\"ugge theory. In the second part, the genetic algorithm is developed. The last part presents a comparative study between various composite materials solutions on a helicopter tail rotor driveline. In particular, hybrid tubes consisting of high modulus and high resistance carbon/epoxy plies are studied. These solutions make it possible to replace the conv...

  5. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications

    OpenAIRE

    Abdulrazzaq, Bilal I.; Omar J. Ibrahim; Shoji Kawahito; Sidek, Roslina M.; Suhaidi Shafie; Nurul Amziah Md. Yunus; Lini Lee; Izhal Abdul Halin

    2016-01-01

    A Delay-Locked Loop (DLL) with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL’s internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS) jitter perf...

  6. Simulation of Chopper Cascade Adjustable Speed System Based on PWM Rectifier%基于PWM整流技术的斩波串级调速系统的仿真

    Institute of Scientific and Technical Information of China (English)

    祝龙记; 周森

    2012-01-01

    A rotor-side chop cascade adjustable speed system based on PWM rectifier was proposed.The PWM rectifier worked on inverter condition and returns slip power of the rotor;this could not only improve the power factor of the system,but also reduce harmonic content of net-side.In Matlab/Simulink,the simulation model of chop cascade adjustable speed system was established.The reasonability and validity were testified by the coincidence of the simulation and experimentation results and theory analysis.%提出将PWM整流技术引入转子侧斩波串级调速系统中,PWM整流器工作于逆变状态回馈转差功率,不仅可以提高串级调速系统的功率因数,还可以减少网侧的谐波含量。在Matlab/Simulink环境下给出了基于PWM整流技术的斩波串级调速系统的仿真模型,最后通过仿真实验验证了控制方案的正确性。

  7. Stabilization of a large-capacity and long-distance transmission system by an adjustable speed flywheel generator; Kahensoku FWG ni yoru daiyoryo chokyori soden keito anteika no kento

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, O; Sato, K.; Goto, K.; Sirosaki, T. [Tohoku Electric Power Co. Inc, Miyagi (Japan); Sanekata, J.; Amano, M.; Endo, M. [Hitachi Ltd., Tokyo (Japan)

    1997-06-20

    An adjustable speed flywheel generator (FWG) is composed of a dynamotor and a flywheel which can accumulate energy as rotational energy. Its adjustable device operates owing to exciting the rotors by three-phase current. When the rotational speed does not coincide with the synchronous one, difference between the two, namely the slipped frequency, excites the rotors. According to this principle, the flywheel can run synchronizing with the transmission system. Selection of the location for FWGs being important from the standpoint of large-capacity and long-distance transmission, a PQ-sensitivity method has been proposed as a new technique, which can estimate the effect of both FWG`s active and reactive power with ease. Besides, regarding an input signal for stabilizing control, new method has been developed which apply the frequency of the bus instead of the power flow. Owing to this method, conventional stepwise changes of the power flow at every opening three-phase single-circuit have disappeared. As for the capacity of the FWG, the fact that the capacity of the exciter depends on the slip investigated, a designing method has been proposed. 8 refs., 17 figs., 3 tabs.

  8. 四驱混合动力轿车分布式卡尔曼车速估计%Vehicle Speed Estimation Based on Distributed Kalman Filter for Four Wheel Drive Hybrid Electric Car

    Institute of Scientific and Technical Information of China (English)

    赵治国; 杨杰; 吴枭威

    2015-01-01

    The driving mode of hybrid electric car can be two-wheel or four-wheel drive. The speed estimation designed for a specific driving mode can hardly achieve high estimated accuracy in all modes. Focus on the changeable driving mode, a kind of distributed Kalman filter with two levels is proposed, by means of utilize vehicle sensors signals, the driving torque of rear in-wheel motors and the torque of front driving wheels at the given gear state. Considering the strongly nonlinear of the model, UKF is adopted to design the filter, and to improve the filter’s robustness on modeling error and signal noise, measurement noise mean and covariance is self-adaptive. Firstly, based on UniTire Model and recursive equation of slip rate, the sub-filter is developed; secondly, based on the vehicle Kinematics model, the master-filter can be developed; at last, in consideration of different driving modes, a more accurate velocity estimation is obtained by fusing information from each sub-filters. With the help of Carsim and Simulink, the simulation platform about four wheel drive hybrid electric car is developed, and the proposed speed estimation algorithm is tested on this platform under the pure electric drive mode and the hybrid drive mode. The results show that the proposed algorithm has not only high precision, but also strong robustness on modeling error, measurement noise and the changeable driving mode.%四驱混合动力轿车存在两轮/四轮多种驱动模式,针对某一驱动模式所设计的车速估计算法难以满足其他模式下车速估计的精度。考虑车辆不同驱动模式,利用车载传感器信号、后轮毂电机转矩信息以及既定档位下前轮转矩信息,提出两级分布式卡尔曼车速估计方法。考虑模型的强非线性,采用无味卡尔曼滤波(Unscented Kalman filter,UKF)算法设计主/子滤波器。同时为了提高UKF算法对模型误差、信号干扰的鲁棒性,实现了量测噪声均值和方

  9. Design of variable frequeney speed-adjusting system of unloading cen-trifuger based on dsPIC control%基于dsPIC控制的离心机变频调速系统的设计

    Institute of Scientific and Technical Information of China (English)

    李小琴

    2013-01-01

    Based on dsPIC30F3010 as the main core components, through software programming the control IPM module FSBB20CH60 which drive AC induction motor variable frequency speed control, and display by LED digital, the keyboard settings, door lock control, design of a good speed performance. The circuit is simple and reliable, cost-effective centrifuges for variable frequency speed control system.%以dsPIC30F3010为主要核心部件,通过软件编程控制IPM模块FSBB20CH60驱动交流感应电机进行变频调速,同时辅以LED数码显示、键盘设置、门锁控制等部分,设计了一个调速性能好、线路简单可靠、性价比高的离心机专用变频调速系统.

  10. Research on Operating Characteristics and Driving Method of High—speed On—off Valve in Clutch Starting%离合起步用高速开关阀工作特性与驱动方法研究

    Institute of Scientific and Technical Information of China (English)

    夏晶晶

    2012-01-01

    In general pulse width modulation (PWM) signal driven,the high - speed on - off solenoid valve opening and closing time are longer,slower reaction, which affected the high-speed on-off solenoid valve control performance. In order to improve the control performance of the high-speed valve,on the basis of the analyses in the operating characteristics of high - speed on - off valve, a multi - hybrid driving method was designed to shorten the opening and closing time,reduce the pressure fluctuations in pressure control to improve the control performance of the valve. In vehicle clutch control,the use of the above method can improve the starting performance,and the engine speed is relatively stable,the driven plate speed increasing trend fluctuation is smaller.%在普通脉宽调制(PWM)信号驱动下,高速开关电磁阀的开启和关闭时间较长,反应慢,影响了高速开关电磁阀的控制性能.为了进一步提高高速开关阀的控制性能,在分析高速开关阀工作特性的基础上,提出了多路混合驱动方法,缩短了高速开关阀的开启和关闭时间,减小了压力控制时的压力波动,改善了高速开关阀的控制性能.在汽车离合器起步控制中,使用该方法很好地改善了汽车的起步性能,发动机转速比较平稳,从动盘转速增加趋势的波动较小.

  11. 柴油机高速电磁阀驱动模块设计与故障诊断%Design of driving module and fault diagnosis for high-speed solenoid valve of diesel

    Institute of Scientific and Technical Information of China (English)

    密刚刚; 周文华; 沈成宇; 郭修其

    2012-01-01

    According to the characteristic of driving current of the high-pressure pump and injectors' highspeed solenoid valve in the electrically controlled fuel injection system of diesel with time-pressure way, the driving circuit was designed, and the respective driving current was derived. Based on the driving circuit's characteristic, the corresponding circuit for fault detecting and diagnosing was proposed, and its veracity was proved through simulating circuit by software on the PC. The integrated fault diagnosis module was completed after the diagnosis algorithm was proposed. And the designed module was applied to an actual project. Then the experiment of actual driving and real-time fault diagnosing was operated on an electrically controlled diesel. The results showed that the pump and injector operated effectually and the parameter of the actual driving current was accurate with the system requirement. When faults occurred on the condition that the diesel worked on the middle or high speed, electronic control unit (ECU) could detect the faults and take effective actions to stop driving actuators timely. So the driving module satisfies the common rail's operating requirement. The detecting and diagnosing of open and short circuit of pump's solenoid valve and short to ground, open and inner short circuit of injector's solenoid valve is implemented. And its veracity and reliability satisfies the demand of system application.%针对时间压力式电控燃油系统的高速电磁阀——高压油泵及喷油器电磁阀的驱动电流特性,设计相应的驱动电路,得到符合要求的驱动电流.根据驱动电路特点,设计相应的故障诊断电路,并用仿真软件验证电路的准确性.在完成相应的诊断软件设计得到完整的诊断模块后,将设计的模块运用于实际工程中,在柴油机上完成了实际模块的驱动和故障诊断试验.试验结果表明:该驱动模块达到了共轨系统驱动要求,同时实现了油泵电

  12. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications.

    Science.gov (United States)

    Abdulrazzaq, Bilal I; Ibrahim, Omar J; Kawahito, Shoji; Sidek, Roslina M; Shafie, Suhaidi; Yunus, Nurul Amziah Md; Lee, Lini; Halin, Izhal Abdul

    2016-09-28

    A Delay-Locked Loop (DLL) with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL's internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS) jitter performance is achievable using a standard 0.13 µm Complementary Metal-Oxide Semiconductor (CMOS) process. The post-layout simulation results show that the power consumption of the proposed DLL architecture's circuit is 0.1 mW when the DLL is operated at 2 GHz.

  13. Design of a Sub-Picosecond Jitter with Adjustable-Range CMOS Delay-Locked Loop for High-Speed and Low-Power Applications

    Directory of Open Access Journals (Sweden)

    Bilal I. Abdulrazzaq

    2016-09-01

    Full Text Available A Delay-Locked Loop (DLL with a modified charge pump circuit is proposed for generating high-resolution linear delay steps with sub-picosecond jitter performance and adjustable delay range. The small-signal model of the modified charge pump circuit is analyzed to bring forth the relationship between the DLL’s internal control voltage and output time delay. Circuit post-layout simulation shows that a 0.97 ps delay step within a 69 ps delay range with 0.26 ps Root-Mean Square (RMS jitter performance is achievable using a standard 0.13 µm Complementary Metal-Oxide Semiconductor (CMOS process. The post-layout simulation results show that the power consumption of the proposed DLL architecture’s circuit is 0.1 mW when the DLL is operated at 2 GHz.

  14. High speed control of electro-mechanical transduction Advanced Drive Techniques for Optimized Step-and-Settle Response of MEMS Micromirrors

    CERN Document Server

    Imboden, Matthias; Pollock, Corey; Lowell, Evan; Akbulut, Mehmet; Morrison, Jessica; Stark, Thomas; Bifano, Thomas G; Bishop, David J

    2015-01-01

    Micro/Nano Electro Mechanical Systems (MEMS/NEMS) provide the engineer with a powerful set of solutions to a wide variety of technical challenges. However, because they are mechanical systems, response times can be a limitation. In some situations, advanced engineered drive techniques can improve response times by as much as a thousand, significantly opening up the application space for MEMS/NEMS solutions.

  15. 直流无刷高速电机驱动电路设计及改进%Design and Improvement of the High - speed Brushless DC Motor Drive Circuit

    Institute of Scientific and Technical Information of China (English)

    石屾; 董春

    2011-01-01

    采用无传感器无刷直流低速电机专用调速控制芯片ML4425,设计制作了航模用直流无刷高速电机的控制器.针对目前航模用直流无刷电机速度高的特点,对用于直流无刷低速电机的传统ML4425控制系统中的相关环节进行了改进,尤其是电机的启动、驱动和保护部分.简化了航模用直流无刷高速电机的控制系统,减少了成本.%In this paper,a dedicated control chip is used to design a drive circuit of a low speed sensorless DC brushless motor.This paper has done some change of the traditional control system of ML4425,in order to adapt to the high speed of the DC brushless motor used in aircraft model, especially in parts of start, drive and protect.Simplified the control system of the DC brushless motor,so it can reduce the cost.

  16. ADJUSTMENT FACTORS AND ADJUSTMENT STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    Tao Benzao

    2003-01-01

    In this paper, adjustment factors J and R put forward by professor Zhou Jiangwen are introduced and the nature of the adjustment factors and their role in evaluating adjustment structure is discussed and proved.

  17. 可调行距高速插秧机移箱机构优化设计%Optimal Design for Seedling Box Mover of Space-adjustable High Speed Rice Transplanter

    Institute of Scientific and Technical Information of China (English)

    熊玮; 朱德泉; 王延庆; 武立权; 蒋锐

    2016-01-01

    移箱机构是可调行距高速水稻插秧机的重要部件,其工作可靠性直接关系到栽植臂的取秧量,对整个插秧机工作性能有着重要影响。为此,通过对现有移箱机构的研究与分析,设计一种可调行距高速水稻插秧移箱机构。运用三维软件对转子和螺旋轴等核心零部件进行实体建模,通过动力学分析软件对其进行虚拟仿真,得出转子与不同过渡曲线的螺旋轴在运动过程中的接触力曲线图,并运用有限元分析软件对正弦过渡曲线的螺旋轴进行强度校核。最后运用多学科优化方法对移箱机构转子进行优化。结果表明:优化后的转子最大应力降低21.8%,移箱机构满足可调行距高速水稻插秧机工作性能要求。%The seedling box mover is an important part of space-adjustable high speed rice transplanter and its operation-al reliability influences the pinching amount of planting arms and working performances of the transplanter.The existing seedling box mover was researched and analyzed to design a new seedling box mover for space-adjustable high speed rice transplanter.Core components such as rotor, sliding sleeve and screw shaft were modeled by three-dimension software and were simulated virtually by dynamic software to obtain the contact force curves between the rotor and the screw shaft with different transition curves.The screw shaft with sine transition curve was analyzed by finite element analyzing soft-ware.The rotor of seedling box mover was optimized by multidisciplinary design optimization method eventually.The re-sult showed that the maximum stress of optimized rotor has reduced 21 .8%and optimized seedling box mover has met the performance demand of space-adjustable high speed rice transplanter.

  18. 风力机与液力变速传动装置匹配工作特性研究%Research on Working Characteristics about Wind Rotor Matching with Hydrodynamic Variable Speed Drive Unit

    Institute of Scientific and Technical Information of China (English)

    董泳; 周绪强; 毕强

    2012-01-01

    通过对液力变速传动装置应用于风力发电系统运动规律的分析,得到了适应变化的风轮转速、保持恒定发电机输入转速的风轮转速与液力变矩器涡轮输出转速应保持的关系。根据传动系的功率分流原理及能量平衡方程,推导了液力变矩器泵轮输入功率占风轮功率的比例以及液力变速传动装置的总体传动效率关系式。结合风力机特性进行了液力变矩器涡轮输出工作特性的分析,综合评价了影响传动效率的主要因素。针对低转速比和高转速比两种型号的液力变矩器进行了系统的匹配计算,为液力元件的选型与设计、差动轮系及定轴轮系关键结构参数的选取提供了参考。%By means of analyzing characteristics of hydrodynamic variable speed umt appneu m wind power system, relationship between wind rotor speed and turbine output speed of hydrodynamic torque converter was achieved comparable to the variable wind rotor speed to sustain constant genera- tor speed. Ratio of input power of torque converter pump to wind rotor power and overall transmis- sion efficiency of hydrodynamic variable speed drive were determined based on the power splitting fun- damentals and energy balance equation. Output working characteristics of hydrodynamic torque con- verter was analyzed combining wind rotor characteristics. Overall evaluation was done with major fac- tors of influencing the transmission efficiency. System matching computation was done in the light of lower speed ratio and higher speed ratio of two types torque converter. Model selection and design for the torque converter,determination of the key construction parameters for differential gear train and ordinary gear train, the research methods and conclusions herein are for reference.

  19. Modelling and Simulation of Vector Control Adjustable-speed System of Asynchronous Motor%三相异步电动机矢量控制调速系统的建模与仿真

    Institute of Scientific and Technical Information of China (English)

    李家荣; 邓智泉

    2001-01-01

    简述了Matlab/Simulink软件的核心内容及已获实际应用的异步电机矢量变换控制系统的数学模型,介绍了用Matlab/Simulink为该系统建立完整仿真模型的过程,最后给出仿真结果.%Introduction is made to the core contents of Matlab/Simulink software and the applied maths model of vector control adjustable-speed system of asynchronous motor. Meanwhile, a brief account is given to the process in which simulation model is established for this system by Matlab/Simulink as well as the simulation results.

  20. Design of EMCCD Driving System for Underwater Low-Light Camera

    Directory of Open Access Journals (Sweden)

    Hou Yuchen

    2016-01-01

    Full Text Available For the core of underwater low-light camera, i.e. EMCCD, the whole solution of driving system is presented in this paper. The timing signals which meet the driving requirements of EMCCD are produced from FPGA. The high-speed integrated driver chips convert the timing signals into general power driving signals with the amplitude under 12V; a Class A push-pull amplifier circuit built in discrete components transforms the timing signals into high-voltage multiplying signals. Besides, the impedance matching for the circuit optimizes the driving system. The experimental results indicate that the driving system generates the high-voltage multiplying signals, with their high level adjusted from 30V to 48V and frequency raised up to 10MHz. The whole driving system satisfies the requirements of EMCCD, and has the capability to ensure the normal operation of EMCCD.

  1. A Novel Harmonic Elimination Approach in Three-Phase Multi-Motor Drives

    DEFF Research Database (Denmark)

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2015-01-01

    industrial drives are still equipped with three-phase diode rectifiers. Thus, it is difficult to implement the prior-art harmonic control strategies for active front-ends. Moreover, the total cost and complexity has become an obstacle for these harmonic elimination approaches in multiple drive systems...... results have validated the effectiveness of the proposed approach in terms of harmonic elimination in three-phase multi-drive systems....... and may cause unnecessary losses in power system transformers. Both degradations are apt to occur in motor drive applications. As a consequence, it calls for advanced and intelligent control strategies for the power electronics based drive systems like adjustable speed drives in industry. At present, many...

  2. 重机LK1900A型高速套结机机械部分的调整与维修%Adjustment and Maintenance of JUKI LK1900A High Speed Lockstitch Bar Tacking Machine

    Institute of Scientific and Technical Information of China (English)

    冯朝荣

    2011-01-01

    本文从重机LK1900A型高速套结机针杆高度的确定、机针与摆梭配合的调整、压脚高度的调整、移动刀和固定刀的调整、挑线杆位置的调整、机械和电气部分常见故障的排除等几个方面,简要介绍了机器的使用调整与维修方法。%The paper discusses the JUKI LK1900A high speed lockstitch bar tacking machine,common faults excluded of mechanical parts,and the methods of machinery adjustment and maintenance.Including affirmatory the height of the needle bar,the needle and swing spindle cooperation,the height of presser foot,position of mobile knife and fixed knife,adjusting the position of thread-taking-up bar,etc.are described.

  3. Analysis of Control Characteristic for the Drive System of Electric Transit Bus

    Institute of Scientific and Technical Information of China (English)

    张承宁; 李红林; 孙逢春; 张旺

    2003-01-01

    The drive control system of the permanent magnetic direct current motor with the enhanced magnetism windings used in the electric transit bus is developed. The mathematics model of the drive control system for this motor is established. The new mode that the added-exiting magnetism field could be weakened and the speed of the motor could be controlled automatically is proposed and realized. The method of root locus design is applied to analyze the acceleration control characteristic. The results of simulation show that the new drive motor control system has extraordinary response characteristic and adjustable performance. Experiments of vehicle running show that the drive control system's antijamming ability is strong and the adjustable performance is fast and smooth, it can meet the demand of power characteristic very well.

  4. Convexity Adjustments

    DEFF Research Database (Denmark)

    M. Gaspar, Raquel; Murgoci, Agatha

    2010-01-01

    A convexity adjustment (or convexity correction) in fixed income markets arises when one uses prices of standard (plain vanilla) products plus an adjustment to price nonstandard products. We explain the basic and appealing idea behind the use of convexity adjustments and focus on the situations...

  5. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  6. 螺旋压力机实现伺服直驱的低速大力矩电动机综述%A survey of low speed large torque motor for driving the screw press

    Institute of Scientific and Technical Information of China (English)

    梁锦涛; 赵升吨; 谢嘉

    2011-01-01

    Various types of low speed large torque motors which are used to drive screw press have been introduced in the text. The structure, working principle,advantages & disadvantages,and domestic & foreign research status have been shown respectively. Finally, several important factors which should be considered in the design process of the motor for driving the screw press have been put forward.%实现伺服直驱是现代螺旋压力机的重要发展方向之一.本文对用于螺旋压力机伺服直驱的各类低速大力矩电动机进行了介绍,阐述其基本结构、工作原理、优缺点以及国内外研究现状.最后提出设计螺旋压力机直驱式电动机需要考虑的几个因素.

  7. High-speed Galvanometer Servo Drive PID + Feedforward Control%高速振镜伺服驱动的PID加前馈控制

    Institute of Scientific and Technical Information of China (English)

    王晓初; 朱照杨; 张国平

    2013-01-01

    This article described the composition of laser marking galvanometer scanning system.In connection the improvement of the performance of the system dynamic performance,high-speed response and accuracy of marking galvanometer servo scanning system with traditional PID control method,and based on establishing the galvanometer system mathematical model,studied the PID + feedforward control model.Therefore,it proved that the PID + feedforward control could gete the rapid response and accuracy through the simulation and experiment.%本文介绍了激光振镜扫描式打标系统的组成,针对振镜伺服扫描系统在传统PID控制方式下,系统动态特性、高速响应以及打标精度等性能的改善,在建立振镜系统数学模型的基础上,研究了PID加前馈控制的控制模型.通过仿真和实验,证明PID加前馈控制可以大大改善打标响应的快速性和精确性.

  8. 调速控制技术在静压传动叉车中的应用%Application of Speed Regulation Technology to Hydrostatic Drive Type Forklift

    Institute of Scientific and Technical Information of China (English)

    张战团

    2012-01-01

    In order to upgrade work efficiency of the hydrostatic-driven forklift truck a method was taken to regulate RPM of the hydraulic motor by readjusting the motor's capacity so that the forklift truck can change its speed according to loaded or unloaded work conditions. 2 types of fork-lift truck were taken for instance, one type is for loading and unloading containers, and the other one is an off-highway type, which was followed by introduction of the 2 types' hydrostatic power regulation.%为提高静压传动叉车的工作效率,采用改变液压马达容积进行调速的方法,使叉车的行走速度能够根据空载和满载的作业工况进行变化.以箱内作业车和越野型叉车为例,分别介绍两种静压传动叉车的调速方法.

  9. Monitoring speed before and during a speed publicity campaign.

    NARCIS (Netherlands)

    Schagen, I.N.L.G. van Commandeur, J.J.F. Goldenbeld, C. & Stipdonk, H.

    2016-01-01

    Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road

  10. A Study on Driver’s Vehicle-following Model Based on High Speed Real Driving Data%基于高速实车驾驶数据的驾驶人跟车模型研究

    Institute of Scientific and Technical Information of China (English)

    袁伟; 付锐; 马勇; 郭应时; 杜春臣

    2015-01-01

    通过实车试验采集驾驶人在高速公路的跟车数据,分析了跟车过程中加速、稳速和减速阶段的划分标准,探讨了稳速跟车阶段驾驶人的期望跟车间距与跟车速度之间的关系,建立期望间距跟车模型,并与自适应巡航控制(ACC)系统所用的安全距离模型进行对比。结果表明:加速和减速阶段,驾驶人的反应并非对称,加速阶段的车辆状态变化更频繁;在稳速跟车阶段,驾驶人的期望跟车间距随车速的升高而增加;与安全距离模型相比,所建立的期望间距跟车模型更符合驾驶人跟车习惯。%The vehicle-following data of drivers are collected on expressway by real vehicle test, and the criteria for classifying the acceleration, deceleration an stable speed phases are analyzed. The relationship between driver’s desired inter-vehicle distance and vehicle-following speed in stable-speed phase is explored, and a vehicle-following model based on desired inter-vehicle distance is established and compared with safe distance model used in adaptive cruise control system. The results indicates that in acceleration and deceleration phases, driver’s response is not symmetrical, and the vehicle state changes more frequently in acceleration phase; while in stable-speed phase, the driver’s desired inter-vehicle distance increases with vehicle speed. It is shown that the presented vehi-cle-following model based on desired inter-vehicle distance is more in accordance with drivers’ driving habits.

  11. Impact drive rotary precision actuator with piezoelectric bimorphs

    Institute of Scientific and Technical Information of China (English)

    Hongzhuang ZHANG; Ping ZENG; Shunming HUA; Guangming CHENG; Zhigang YANG

    2008-01-01

    An impact drive rotary precision actuator with end-loaded piezoelectric cantilever bimorphs is proposed. According to finite element analysis and experiments of the dynamic characteristics of end-loaded piezoelectric cantilever bimorphs, a specific fixed-frequency and adjustable-amplitude is confirmed to control the actua-tor. The results show that an actuator excited by fixed-frequency and the adjustable-amplitude ramp voltage waveform works with a large travel range (180°), high resolution (1 μrad), speed (0.2 rad/min) and heavy-load ability (0.02 Nm). With advantages of high-precision positioning ability, simple structure and only one percent the cost of traditional impact drive mechanisms, the actuator is expected to be widely used in precision industries.

  12. Development of a Test Machine for IVECO Drive Axle

    Institute of Scientific and Technical Information of China (English)

    WANG Liang-mo; WANG He-fu; CHEN Jin-rong; LING Zhi-liang; CAO Yu-hua

    2007-01-01

    To improve the automation level of the vehicle drive axle test and better simulate a vehicle′s actual operation, an advanced test machine has been developed. The load system of the machine consists of hand brakes and electric cylinders. It is simple-structured and low-cost. The major motor of the machine is controlled by a transducer and its speed can be adjusted easily. In addition, the programmed machine can automatically test such parameters as the grinding condition, the differential speed, the noise level, etc. It can also adjust the test procedures according to different requirements. Detailed discussion of the structure and mechanism of the test machine is given in this paper.

  13. Deliberately dispatched SCR firing angles for harmonic mitigation in three-phase multi-drive systems without communication

    DEFF Research Database (Denmark)

    Yang, Yongheng; Davari, Pooya; Zare, Firuz;

    2016-01-01

    Adjustable Speed Drives (ASDs) are widely used in threephase multi-drive applications in industry, where low-cost Diode Rectifiers (DRs) or Silicon-Controlled Rectifiers (SCRs) are still employed as the front-ends in practice, also for simplicity. However, the associated harmonics are produced...... witnessed in industry. In this sense, this paper proposes a harmonic mitigation strategy for multiple parallel ASD systems, where the firing angles of the SCR units are deliberately dispatched among the SCR drive units, resulting in certain phase shifts of the SCR currents on purpose. In such a manner...

  14. Driving Parameter Selection of High-speed Solenoid Valve for High-pressure Common Rail System%高压共轨系统高速电磁阀驱动参数优选方法研究

    Institute of Scientific and Technical Information of China (English)

    白思春; 褚全红; 孟长江; 姜承赋; 贾利; 杨薇; 李晨; 苏莉; 陈鲜萍

    2012-01-01

    A method of selecting parameter for different solenoid valves was introduced,to ensure the quick opening, reliable contacting and rapid turn-off of solenoid valve in the high-pressure common rail system. By measuring the injection quantity on the injection pump test bed, the parameters of driving voltage, open-current and holding current for solenoid valve were determined. In addition, the method did not need to consider the complicated electric, magnetic and liquid factors in the system. With the method, the high-speed solenoid valve of a high-pressure common rail system was tested. The driving parameters were acquired by the optimization and verified through the steady test in the injection pump test bed. The result shows that the method can meet the engineering application requirements.%介绍了一种对不同电磁阀进行参数优选的方法,以保证高压共轨控制系统中电磁阀的快速开启、可靠吸合和快速关断.该方法通过在喷油泵试验台上测试喷油量,确定出电磁阀驱动电压、开启电流及维持电流参数,不需要考虑系统复杂的电、磁、液综合因素.应用该方法对某高压共轨部件高速电磁阀进行试验,优化出驱动参数,并在喷油泵试验台上进行了稳定性试验验证,结果表明该方法能够满足工程应用.

  15. Demonstration of variable speed permanent magnet generator at small, low-head hydro site

    Energy Technology Data Exchange (ETDEWEB)

    Brown Kinloch, David [Shaker Landing Hydro Associates, Inc., Louisville, KY (United States)

    2015-12-18

    Small hydro developers face a limited set of bad choices when choosing a generator for a small low-head hydro site. Direct drive synchronous generators are expensive and technically complex to install. Simpler induction generators are higher speed, requiring a speed increaser, which results in inefficiencies and maintenance problems. In addition, both induction and synchronous generators turn at a fixed speed, causing the turbine to run off its peak efficiency curve whenever the available head is different than the designed optimum head.The solution to these problems is the variable speed Permanent Magnet Generators (PMG). At the Weisenberger Mill in Midway, KY, a variable speed Permanent Magnet Generator has been installed and demonstrated. This new PMG system replaced an existing induction generator that had a HTD belt drive speed increaser system. Data was taken from the old generator before it was removed and compared to data collected after the PMG system was installed. The new variable speed PMG system is calculated to produce over 96% more energy than the old induction generator system during an average year. This significant increase was primarily due to the PMG generator operating at the correct speed at the maximum head, and the ability for the PMG generator to reduce its speed to lower optimum speeds as the stream flow increased and the net head decreased.This demonstration showed the importance of being able to adjust the speed of fixed blade turbines. All fixed blade turbines with varying net heads could achieve higher efficiencies if the speed can be matched to the optimum speed as the head changes. In addition, this demonstration showed that there are many potential efficiencies that could be realized with variable speed technology at hydro sites where mismatched turbine and generator speeds result in lower power output, even at maximum head. Funding for this project came from the US Dept. of Energy, through Award Number DE-EE0005429.

  16. Driving Resistance from Railroad Trains

    DEFF Research Database (Denmark)

    Lindgreen, Erik Bjørn Grønning; Sorenson, Spencer C

    2005-01-01

    This report methods and parameters for calculating the driving resistance of railroad trains. Calculations and comparisons are presented for aerodynamic, rolling and total resistance for a variety of freight trains under different loading conditions, operating speed and configuration. Simplified...... methods are presented for the estimation of the driving resistance for passenger trains. This report is a supplement to the ARTEMIS rail emissions model....

  17. Influence of roadside infrastructure on driving behavior: driving simulator study

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Ridder, S. de

    2007-01-01

    This paper describes the results of a driving simulator study that focused on the influence of roadside infrastructure on speed choice and lateral placement of car drivers. A review of the RISER detailed accident database revealed that lateral positioning and speed of the vehicle were two of the pri

  18. Drugged Driving

    Science.gov (United States)

    ... Parents & Educators Children & Teens Search Connect with NIDA : Google Plus Facebook LinkedIn Twitter YouTube Flickr RSS Menu ... misuse of prescription drugs can make driving a car unsafe—just like driving after drinking alcohol. Drugged ...

  19. Optimization design of wind turbine drive train based on Matlab genetic algorithm toolbox

    Science.gov (United States)

    Li, R. N.; Liu, X.; Liu, S. J.

    2013-12-01

    In order to ensure the high efficiency of the whole flexible drive train of the front-end speed adjusting wind turbine, the working principle of the main part of the drive train is analyzed. As critical parameters, rotating speed ratios of three planetary gear trains are selected as the research subject. The mathematical model of the torque converter speed ratio is established based on these three critical variable quantity, and the effect of key parameters on the efficiency of hydraulic mechanical transmission is analyzed. Based on the torque balance and the energy balance, refer to hydraulic mechanical transmission characteristics, the transmission efficiency expression of the whole drive train is established. The fitness function and constraint functions are established respectively based on the drive train transmission efficiency and the torque converter rotating speed ratio range. And the optimization calculation is carried out by using MATLAB genetic algorithm toolbox. The optimization method and results provide an optimization program for exact match of wind turbine rotor, gearbox, hydraulic mechanical transmission, hydraulic torque converter and synchronous generator, ensure that the drive train work with a high efficiency, and give a reference for the selection of the torque converter and hydraulic mechanical transmission.

  20. Chiropractic Adjustment

    Science.gov (United States)

    ... syndrome) A certain type of stroke (vertebral artery dissection) after neck manipulation Don't seek chiropractic adjustment ... Chiropractic treatment. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015. Shekelle P, et al. Spinal ...

  1. Electromechanical performance of induction motor/drive systems subjected to voltage sags

    Science.gov (United States)

    Tunaboylu, Serdar N.

    Induction Motors are workhorses for many industries. They are extensively utilized in industrial variable-frequency drive (VFD) or adjustable-speed drive (ASD) applications as well as constant speed applications. Recent advances in power electronics have made AC motor drives an economically viable solution for ASD applications traditionally dominated by dc motor drives. In this study, electromechanical performance variables of an Induction Motor (IM) have been studied during the balanced voltage sags. For this purpose a laboratory prototype of an industrial mixer has been designed. IM has been coupled to a speed reducer that is worm gear type with a ratio 10 to 1. Then the reducer is vertically coupled to a food process mixer within a metal canister. The mixer represents a high friction load with practically zero inertia. Voltage, current, speed, and power measurements have been collected and compared with the simulation results from Simnon. An open-loop control Volts per Hertz boost strategy has been used in order to compensate the speed loss during the three-phase balanced voltage sags. Both compensated and uncompensated cases have been run and compared with simulation results. Results are verified with a reasonably good agreement that the total system modeling is successful and boost compensation circuit is effective.

  2. Energy optimized sliding-mode control of sensorless induction motor drives

    Energy Technology Data Exchange (ETDEWEB)

    Hajian, M.; Soltani, J.; Hoseinnia, S. [Faculty of Electrical and Computer Engineering, Isfahan Univ. of Technology, Isfahan (Iran); Arab Markadeh, G.R. [Faculty of Engineering, Univ. of Shahrekord, Shahrekord (Iran)

    2009-09-15

    In this paper a sensorless sliding-mode (SM) direct torque and flux control is described for three-phase induction motor (IM) drive. The IM drive is supplied with a two level space vector modulation (SVM) voltage source inverter. A conventional PI speed controller is employed to generate the desired torque command in the case of speed control. Stator and rotor flux vectors are estimated using a sliding-mode observer and are employed in rotor speed estimation. Moreover, the IM model includes the iron losses through a speed dependent shunt resistance in the motor two axis equivalent circuits. Motor efficiency is also optimized by adjusting the magnitude of the stator flux reference for each value of motor load and speed. For this purpose, an on-line search method (OSM) is adopted. According to this method, for each given value of load torque and rotor speed, the stator flux reference is adjusted so that the average of real input power becomes minimized. Simulation and experimental results are presented to show the capability and validity of the proposed control scheme. (author)

  3. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  4. 烟草柜式喂料机出柜自动调速系统的设计%Design of Automatic Discharge Speed Adjusting System for Silo Type Tobacco Feeder

    Institute of Scientific and Technical Information of China (English)

    张梓泳

    2014-01-01

    To reduce labor intensity and avoid tobacco jam,tobacco flow interruption and frequent start/stop operation in manual operation of the discharge from the silo type tobacco feeder,an automatic discharge speed adjusting system was designed with industrial Ethernet and distributed programmable control technology. The system was mainly composed of a programmable logic controller, frequency converters, motors and photoelectric switches. By monitoring the status of photoelectric switches installed on the high,middle and low levels of metering tube,the running frequencies of bottom belt and elevating belt were adjusted. The results showed that the automatic system reduced manual adjusting from 26 to 3 times/batch,tobacco jam,tobacco flow interruption and start/stop of equipment decreased from 3.4 to 0.2,from 2 to 0.2,and from 182 to 36 times/batch,respectively. It ensured the consistent tobacco flow supplying to the downstream equipment.%为解决烟草柜式喂料机出柜控制过程中存在的操作人员劳动强度大、堵料、断料及设备启停频繁等问题,利用工业以太网和分布式可编程控制技术设计了烟草柜式喂料机出柜自动调速系统。系统主要由可编程控制器、变频器、电机和对射式光电开关等组成,信号通过对喂料机底带电机和提升带电机运行频率构建控制模型,循环检测限量管高、中、低料位光电开关的遮挡状态,并根据光电开关不同状态组合,分别对底带电机和提升带电机的运行频率进行调整。结果表明:系统实现了物料出柜的快速自动调速,人工调节频次由26次/批次减少为3次/批次,堵料情况由3.4次/批次减少为0.2次/批次,断料情况由2次/批次减少为0.2次/批次,设备启停次数由182次/批次降低为36次/批次。改进后系统为后序加工设备提供了稳定的物料流量,保证了卷烟产品的工艺品质。

  5. The construction of an electrode biasing system for driving plasma rotation in J-TEXT tokamak

    Science.gov (United States)

    Zhu, T. Z.; Chen, Z. P.; Sun, Yue; Nan, J. Y.; Liu, H.; Zhuang, G.; Wang, Z. J.

    2014-05-01

    A newly designed electrode biasing system has been constructed for driving plasma rotation in J-TEXT tokamak. To reduce the influence to the plasma, the system contains a pneumatic driving system so that it can reciprocate in a single discharge, with a stroke of about 5 cm in 100 ms. The power supply of the system can provide stable and adjustable dc voltage in the range of 0-700 V, with adjustable duration of 10-200 ms; its instantaneous power output can reach up to more than 200 kW. In addition, the power supply can also provide a multi-cycle voltage waveform, with adjustable pulse width and voltage amplitude. When applying a positive bias to the plasma, both an improvement of plasma confinement and the speed-up of plasma-edge toroidal rotation in the same direction of plasma current are observed in the experiments.

  6. Preliminary results from the Danish Intelligent Speed Adaptation project Pay as You Speed

    DEFF Research Database (Denmark)

    Agerholm, Niels; Waagepetersen, Rasmus; Tradisauskas, Nerius

    2008-01-01

    The driving behaviour of participants in the Danish Intelligent Speed Adaptation (ISA) project `Pay as You Speed' (PAYS) is described. The project is the first ISA project based on Pay as You Drive principles. Thus, the ISA equipment both notifies the driver that he/she is speeding (`information...

  7. Enhanced dynamic Performance of Matrix Converter Cage Drive with Neuro-fuzzy approach

    Directory of Open Access Journals (Sweden)

    R.R. Joshi

    2007-06-01

    Full Text Available This paper proposes a new control algorithm for a matrix converter (MC induction motor drive system. First, a new switching strategy, which applies a back-propagation neural network to adjust a pseudo dc bus voltage, is proposed to reduce the current harmonics of the induction motor. Next, a two-degree-of-freedom controller is proposed to improve the system performance. The controller design algorithm can be applied in an adjustable speed control system and a position control system to obtain good transient responses and good load disturbance rejection abilities. The implementation of this kind of controller is only possible by using a high-speed digital signal processor. In this paper, all the control loops, including current-loop, speed-loop, and position-loop, are implemented by TMS320C6711 digital signal processor. Several experimental results are shown to validate the theoretical analysis.

  8. Library of Samples for E-Vehicle Propulsion Drive Tuning

    Directory of Open Access Journals (Sweden)

    Rassõlkin Anton

    2014-05-01

    Full Text Available The majority of testing cycles for the vehicle comparison is the long-term cycles and could not be used for the short-term transient mode imitations. Also, all the used nowadays testing cycles were designed for internal combustion engine vehicles and take into account not only energy and mechanical aspects, but also pollution and internal combustion engine characteristics. The paper presents a collection of sample signals developed to explore and simulate multiple system impacts to emulate different reference and load conditions. The study describes the major driving modes, such as the constant-speed cruising, speeding up and braking, typical parking regimes, uphill and downhill motion, and taking a turn. The developed testing equipment and software are described. Responses of the battery vehicle drives to the changeable controls and disturbances were studied in the laboratory test bench. The set of test cycles prepared in the frame of the ABB control arrangement was applied to the system evaluation and assessment. The developed methodology can be recommended to adjust the electric drives for different kinds of testing equipment. Experimental validation of the described approach has demonstrated the broad possibilities for the steady-state and transient modes of vehicle quality evaluation. It suits for recommendations that can be made with regard to the tuning of the drive regulators, control looping, sensor allocation, and feedback arrangements.

  9. Roller/Gear Drives For Robotic Manipulators

    Science.gov (United States)

    Anderson, William J.; Shipitalo, William

    1995-01-01

    Pitch/yaw roller/gear drive and wrist-roll roller/gear drive designed to incorporate several features desirable in robotic-joint actuators. Includes zero backlash, high efficiency, smooth motion (little ripple in torque and in speed ratio), and high degree of back-drivability. Pitch/yaw drive is novel two-axis drive containing combination of gears, rollers, and springs acting together eliminating backlash and cogging. Wrist-roll drive more-conventional single-axis drive offering advantages like those of pitch/yaw drive.

  10. Pile Driving

    Science.gov (United States)

    1987-01-01

    Machine-oriented structural engineering firm TERA, Inc. is engaged in a project to evaluate the reliability of offshore pile driving prediction methods to eventually predict the best pile driving technique for each new offshore oil platform. Phase I Pile driving records of 48 offshore platforms including such information as blow counts, soil composition and pertinent construction details were digitized. In Phase II, pile driving records were statistically compared with current methods of prediction. Result was development of modular software, the CRIPS80 Software Design Analyzer System, that companies can use to evaluate other prediction procedures or other data bases.

  11. Driving characteristics of teens with attention deficit hyperactivity and autism spectrum disorder.

    Science.gov (United States)

    Classen, Sherrilene; Monahan, Miriam; Wang, Yanning

    2013-01-01

    Vehicle crashes are a leading cause of death among teens. Teens with attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), or both (ADHD-ASD) may have a greater crash risk. We examined the between-groups demographic, clinical, and predriving performance differences of 22 teens with ADHD-ASD (mean age = 15.05, standard deviation [SD] = 0.95) and 22 healthy control (HC) teens (mean age = 14.32, SD = 0.72). Compared with HC teens, the teens with ADHD-ASD performed more poorly on right-eye visual acuity, selective attention, visual-motor integration, cognition, and motor performance and made more errors on the driving simulator pertaining to visual scanning, speed regulation, lane maintenance, adjustment to stimuli, and total number of driving errors. Teens with ADHD-ASD, compared with HC teens, may have more predriving deficits and as such require the skills of a certified driving rehabilitation specialist to assess readiness to drive.

  12. Permanent magnetic toroidal drive with half stator

    Directory of Open Access Journals (Sweden)

    Lizhong Xu

    2017-01-01

    Full Text Available A permanent magnetic toroidal drive with a half stator is proposed that avoids noise and mechanical vibrations. The effects of the system parameters on the output torque of the drive were investigated. A model machine was designed and produced. The output torque and speed fluctuation of the drive system were measured, and the calculated and measured output torque were compared. The tests demonstrated that the drive system could operate continuously without noise, and the system achieved a given speed ratio. The drive system had high load-carrying ability and a maximum output torque of 0.15 N m when certain parameter values were used.

  13. Salary adjustments

    CERN Multimedia

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, the following elements do not increase: a)\tFamily Allowance, Child Allowance and Infant Allowance (Annex R A 3); b)\tReimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be applied, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and rounding effects. Human Resources Department Tel. 73566

  14. Salary adjustments

    CERN Multimedia

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, following elements do not increase: a) Family Allowance, Child Allowance and Infant Allowance (Annex R A 3). b) Reimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be implemented, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and the rounding effects. Human Resources Department Tel. 73566

  15. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  16. Speeding Up

    Institute of Scientific and Technical Information of China (English)

    YU SHUJUN

    2010-01-01

    In the wake of the global financial crisis, China has amazed the world with the speed of its economic recovery. But what has been even more surprising is the speed of its railway evolution. The unveiling of the 1,069-km Wuhan-Guangzhou High-speed Railway on December 26, 2009 pushed China's high-speed rail sys-tem-the total mileage, the average speed and the technology-to rank first in the world almost overnight.

  17. DRIVING GREEN

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    China is promoting environmentally friendly cars to save energy and protect the environment While people enjoy the pleasure and convenience of driving, they are also creating and breathing more and more toxic

  18. Distracted Driving

    Science.gov (United States)

    ... What's this? Submit What's this? Submit Button Distracted Driving Recommend on Facebook Tweet Share Compartir Each day in the United States, over 8 people are killed and 1,161 injured in crashes ...

  19. Comparison Between Line Start PM Synchronous Motor and Induction Motor With Same Nominal Power and Same Pole Pairs When Fed By VF Control Drive

    Directory of Open Access Journals (Sweden)

    Ali Reza Sadoughi

    2015-03-01

    Full Text Available Given the importance of electric machines in the industry with high efficiency, and speed control of this machines are also important, in this paper, three-phase line start permanent magnet synchronous motor and three-phase induction motors that are same in nominal power and the number of poles, is controled, monitored and compared by open-loop voltage to frequency drive, with each other. To this end, simulating the same conditions for the launch of electronic drive with open loop control V/Hz with constant load torque is provided.Simulation results from MATLAB/Simulink software are presented for both line-starting and Adjustable Speed Drive (ASD applications in the same situations, to provide a comprehensive comparison, and it shows a transient and steady-state response of an LSPMSM drive compared to its IM.

  20. The advantage of variable speed for multistage centrifugal blowers used in waste-water treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Huang, X. [Gardner Denver Incorp., Peachtree City, GA (United States)

    1999-07-01

    The multistage centrifugal blower is primarily a 60 Hz market product. A two-pole AC induction motor directly drives the blower at 3600 RPM. These blowers have been used widely for the last three decades in the US for waste water treatment plant applications (WWTP) due to their simple design and rugged construction. The cost of energy drives the market towards not only an efficient single design point but also an efficient operating range when both flow and pressure are varied. On the other hand, if a blower is running at 3000 RPM as in the 50 Hz market, about 20% of flow and 40% of pressure are lost comparing to a 60 Hz application. To meet these new market challenges, the Variable Frequency Drive (VFD) multistage centrifugal blower was designed, where the VFD serves not only as speed adjusting device to maximise the efficiency but also as a speed increaser to minimise the blower size. For existing WWTP installations, retrofit to a VFD drive requires minimum investment and leadtime while achieving drastic energy savings. A comparison with the gear drive high-speed single stage blower concept is also made. (Author)

  1. Monitoring speed before and during a speed publicity campaign.

    Science.gov (United States)

    van Schagen, Ingrid; Commandeur, Jacques J F; Goldenbeld, Charles; Stipdonk, Henk

    2016-12-01

    Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road-side radars, mounted in light poles, were used and registered the speeds on 20 locations in built-up areas. Speeds of over 10 million vehicles were measured. Ten locations had a posted speed limit of 50km/h; the other ten had a posted speed limit of 30km/h. Posters were placed at half of each group of locations to remind drivers of the speed limit. The average speed on the 50km/h roads was 46.2km/h, and 36.1km/h on the 30km/h roads. The average proportions of vehicles exceeding the speed limit were 33.3% and 70.1% respectively. For the 30km/h roads, the data shows differences in speed and speeding behaviour between the six distinguished observation periods, but overall these differences cannot be logically linked to the contents of the phases and, hence, cannot be explained as an effect of the campaign. The only exception was an effect of local speed limit reminders on the 30km/h roads. This effect, however, was temporary and had disappeared within a week.

  2. The relation between speed and crashes.

    NARCIS (Netherlands)

    2006-01-01

    The exact relation between speed and crashes depends on many factors. However, in a general sense the relation is very clear: if on a road the driven speeds become higher, the crash rate will also increase. The crash rate is also higher for an individual vehicle that drives at higher speed than the

  3. An Improved Power Quality Based Sheppard-Taylor Converter Fed BLDC Motor Drive

    Science.gov (United States)

    Singh, Bhim; Bist, Vashist

    2015-12-01

    This paper deals with the design and analysis of a power factor correction based Sheppard-Taylor converter fed brushless dc motor (BLDCM) drive. The speed of the BLDCM is controlled by adjusting the dc link voltage of the voltage source inverter (VSI) feeding BLDCM. Moreover, a low frequency switching of the VSI is used for electronically commutating the BLDCM for reduced switching losses. The Sheppard-Taylor converter is designed to operate in continuous conduction mode to achieve an improved power quality at the ac mains for a wide range of speed control and supply voltage variation. The BLDCM drive is designed and its performance is simulated in a MATLAB/Simulink environment to achieve the power quality indices within the limits of the international power quality standard IEC-61000-3-2.

  4. Maximum torque per ampere control of sensorless induction motor drives with dc offset and parameter compensation

    Energy Technology Data Exchange (ETDEWEB)

    Markadeh, Gholamreza Arab [Faculty of Engineering, Shahrekord University, Shahrekord (Iran, Islamic Republic of); Hajian, Masood, E-mail: m.hajian@ec.iut.ac.i [Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Soltani, Jafar; Hosseinia, Saeed [Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2010-07-15

    Field orientation control of induction machine (IM) drives is a well-known strategy which has a fast dynamic response. In this paper, the direct rotor flux field orientation control of speed sensorless IM drive is presented. A two level space vector modulation inverter is employed to generate the command stator voltage. In proposed control scheme, a maximum torque per ampere strategy is achieved using a so-called fast flux search method. Based on this method, for a given load torque and rotor speed, the magnitude of rotor reference flux is adjusted step by step until the effective value of stator current becomes minimized finally. In addition, using the IM fifth order model in the stationary reference frame, a nonlinear rotor flux observer is developed which is also capable of motor resistances and rotor speed simultaneously estimation. Moreover, a useful method is introduced for dc offset compensation which is a major problem of ac drives especially at low speeds. The proposed control idea is experimentally implemented in real time using a CPLD board synchronized with a personal computer. Simulation and experimental results are finally presented to confirm the validity and effectiveness of the proposed method.

  5. Death Drive

    OpenAIRE

    Stühler, Rebekka Hellstrøm

    2012-01-01

    The aim of this project is to investigate why the Freudian term Death Drive is not acknowledged in modern psychological therapy. On basis of psychoanalytical theory and through a literary analysis, the project will present a discussion of the significance and presence of the term within these practises.

  6. PERSONALITY AND SPEEDING

    Directory of Open Access Journals (Sweden)

    Richard TAY

    2003-01-01

    Full Text Available While there has been extensive research on the effect of sensation seeking on risky driving, relatively little research has been conducted on Type-A personality. The motivations for speeding are likely to be different for each group and these differences have important implications for the design, implementation and expected efficacy of road safety countermeasures. This paper examines the influence of sensation seeking and Type-A behavior pattern on speeding behaviour. A sample of 139 staff and students in an Australian university were surveyed in July 2001 to gather information on their gender, age, personality and self-reported speeding behaviour. The data were analysed using correlations and analysis of variance procedures. Finally, some implications for road safety are discussed.

  7. Safe Driving and Executive Functions in Healthy Middle-Aged Drivers.

    Science.gov (United States)

    León-Domínguez, Umberto; Solís-Marcos, Ignacio; Barrio-Álvarez, Elena; Barroso Y Martín, Juan Manuel; León-Carrión, José

    2016-04-18

    The introduction of the point system driver's license in several European countries could offer a valid framework for evaluating driving skills. This is the first study to use this framework to assess the functional integrity of executive functions in middle-aged drivers with full points, partial points or no points on their driver's license (N = 270). The purpose of this study is to find differences in executive functions that could be determinants in safe driving. Cognitive tests were used to assess attention processes, processing speed, planning, cognitive flexibility, and inhibitory control. Analyses for covariance (ANCOVAS) were used for group comparisons while adjusting for education level. The Bonferroni method was used for correcting for multiple comparisons. Overall, drivers with the full points on their license showed better scores than the other two groups. In particular, significant differences were found in reaction times on Simple and Conditioned Attention tasks (both p-values functioning on driving ability.

  8. A method to change frictional characteristics based on ultrasonic micro driving technique

    Institute of Scientific and Technical Information of China (English)

    CHEN Weishan; ZHANG Fan; LIU Junkao

    2006-01-01

    In order to reduce friction force and eliminate stick-slip phenomenon of a mechanic system at a low velocity, a method based on the ultrasonic micro driving technique to change the frictional characteristics is proposed. Exciting clockwise and anticlockwise microscopic elliptical motion of driving points on the ultrasonic actuator's two longitudinal bolt-clamped vibrators will generate ultrasonic lubrication action; furthermore, the friction can be actively controlled by adjusting the vibrators' vibrating amplitude. An experimental installation for friction control is designed using aerostatic guide, force sensors and a low speed moment motor.Fuzzy control theory is applied into this system. The experiments indicate the friction force has been reduced largely and the motion of the experimental system is stable. The friction coefficient is only about 0.0053 when the total mass of the ultrasonic actuator and load is3.8 kg and the motor's driving velocity is 0.5 mm/s.

  9. High Torque, Direct Drive Electric Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to advance the development of an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such...

  10. High Torque, Direct Drive Electric Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Bear Engineering proposes to develop an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such devices. Fundamentally,...

  11. Wind energy conversion. Volume IV. Drive system dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Sanchez, M.; Labuszewski, T.

    1978-09-01

    The dynamics of the drive system and various approaches to power transmission are described. The effects on performance of using a constant rotor speed as opposed to a rotor speed varying with the wind speed are discussed for various rotor operating schedules and typical wind distributions. The dynamics of the combined rotor, alternator, and drive system are analyzed. Conditions which could lead to electro-dynamic instabilities and desynchronization are discussed as well as means for stabilizing the system. The dynamics of the drive system and important design conditions for various drive systems are discussed, such as location of the alternators, use of hydraulic drive systems and smoothing techniques.

  12. Digital control of electrical drives

    CERN Document Server

    Vukosavic, Slobodan N

    2007-01-01

    Offers insight into electric drives and their usage in motion control environment. This book provides links among electrical machine and control theory, practical hardware aspects, programming issues, and application-specific problems. It covers the key elements of motion control systems, and discrete-time speed and position controllers.

  13. Gaze-controlled Driving

    DEFF Research Database (Denmark)

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...... from the moving robot. Gaze control was found to be similar to mouse control. This suggests that robots and wheelchairs may be controlled “hands-free” through gaze. Low precision gaze tracking and image transmission delays had noticeable effect on performance....

  14. Electrical machines and drives

    CERN Document Server

    Hindmarsh, John

    2002-01-01

    Recent years have brought substantial developments in electrical drive technology, with the appearance of highly rated, very-high-speed power-electronic switches, combined with microcomputer control systems.This popular textbook has been thoroughly revised and updated in the light of these changes. It retains its successful formula of teaching through worked examples, which are put in context with concise explanations of theory, revision of equations and discussion of the engineering implications. Numerous problems are also provided, with answers supplied.The third edition in

  15. Self-Commissioning of AC Motor Drives

    OpenAIRE

    Odhano, Shafiq Ahmed

    2014-01-01

    In modern motion control and power conversion applications, the use of inverter-fed electrical machines is fast growing with continuous development in the field of power electronics and drives. The Variable Voltage Variable Frequency (VVVF) supply for electrical machines gives superior performance in terms of speed control, efficiency and dynamics compared to the machines operated directly from the mains. In one of the most basic configurations, a drive system consists of a closed loop speed ...

  16. Multi-propeller drive system

    Science.gov (United States)

    Belenger, Robert V.

    1995-05-01

    A multipropeller drive system having a single input shaft for connection to an engine system, a differential gear assembly for dividing the driving force from the input drive shaft between a pair of output shafts, and a pair of laterally spaced propellers driven by the output shafts of the differential gear assembly is disclosed. The differential gear assembly operates in a manner wherein one output shaft, if required, is permitted to revolve at a different rate than the other output shaft. A pair of brake mechanisms acting on the output shafts of the differential gear assembly enable an operator to control the rotational speed of the respective propellers without modifying the engine speed or transmission settings.

  17. Can anti-speeding messages based on protection motivation theory influence reported speeding intentions?

    Science.gov (United States)

    Glendon, A Ian; Walker, Britta L

    2013-08-01

    The study investigated the effects of anti-speeding messages based on protection motivation theory (PMT) components: severity, vulnerability, rewards, self-efficacy, response efficacy, and response cost, on reported speeding intentions. Eighty-three participants aged 18-25 years holding a current Australian driver's license completed a questionnaire measuring their reported typical and recent speeding behaviors. Comparisons were made between 18 anti-speeding messages used on Australian roads and 18 new anti-speeding messages developed from the PMT model. Participants reported their reactions to the 36 messages on the perceived effectiveness of the message for themselves and for the general population of drivers, and also the likelihood of themselves and other drivers driving within the speed limit after viewing each message. Overall the PMT model-derived anti-speeding messages were better than jurisdiction-use anti-speeding messages in influencing participants' reported intention to drive within the speed limit. Severity and vulnerability were the most effective PMT components for developing anti-speeding messages. Male participants reported significantly lower intention to drive within the speed limit than did female participants. However, males reported significantly higher intention to drive within the speed limit for PMT-derived messages compared with jurisdiction-based messages. Third-person effects were that males reported anti-speeding messages to be more effective for the general driving population than for themselves. Females reported the opposite effect - that all messages would be more effective for themselves than for the general driving population. Findings provided support for using a sound conceptual basis as an effective foundation for anti-speeding message development as well as for evaluating proposed anti-speeding messages on the target driver population.

  18. Quantum effects in warp drives

    Directory of Open Access Journals (Sweden)

    Finazzi Stefano

    2013-09-01

    Full Text Available Warp drives are interesting configurations that, at least theoretically, provide a way to travel at superluminal speed. Unfortunately, several issues seem to forbid their realization. First, a huge amount of exotic matter is required to build them. Second, the presence of quantum fields propagating in superluminal warp-drive geometries makes them semiclassically unstable. Indeed, a Hawking-like high-temperature flux of particles is generated inside the warp-drive bubble, which causes an exponential growth of the energy density measured at the front wall of the bubble by freely falling observers. Moreover, superluminal warp drives remain unstable even if the Lorentz symmetry is broken by the introduction of regulating higher order terms in the Lagrangian of the quantum field. If the dispersion relation of the quantum field is subluminal, a black-hole laser phenomenon yields an exponential amplification of the emitted flux. If it is superluminal, infrared effects cause a linear growth of this flux.

  19. 石武客专P60-1/18板式无砟高速道岔安装与精调技术%Installation and Fine Adjustment Technology of P60-1/18 Slab Turnout for Shijiazhuang-Wuhan High-speed Passer Railway

    Institute of Scientific and Technical Information of China (English)

    范伟

    2012-01-01

    以石武客专P60-1/18板式无砟高速道岔安装施工为背景,介绍了P60-1/18板式无砟高速道岔安装及精调的过程.详细论述了道岔安装前的准备工作,道岔安装的工艺流程,精调时采取的步骤,调整时均应遵循的原则并满足的要求,道岔焊接应注意的事项.对类似板式无砟高速道岔安装具有指导意义.%Taking Shijiazhuang-Wuhan passenger dedicated high-speed railway as an example, this paper introduces the installation and fine adjustment procedure of P60-1/18 high-speed slab turnout. The key issues a-bout the turnout are discussed: preparation work before erection of the rail turnout, flowchart of rail turnout erection, rail welding, and steps and principles for fine adjustment. The paper can provide some reference for the installation of similar non-ballast turnout.

  20. Hierarchical control strategy of reactive power for wind farm based on the composition of the front-end speed adjusting wind turbine%基于前端调速式风电机组的风电场无功分层控制策略*

    Institute of Scientific and Technical Information of China (English)

    燕尧; 董海鹰

    2015-01-01

    前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化而引起的并网点电压波动的问题,提出了一种前端调速式风电场无功电压分层控制策略。该策略首先确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。%The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability. Aiming at the wind farm with the front-end speed adjusting wind turbine exists grid connection node voltage fluctuation problem caused by the change of wind power, a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm is proposed. The strategy determines the selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains the reactive power demand of the whole wind farm by the tuning control. The minimum real power loss of the wind farm is used as objective function to allocate to each wind turbine based on the optimized and improved genetic algorithm. The strategy combines the reactive power output of the Static Synchronous Compensator to adjust the reactive power output of the whole wind farm and thus to achieve the purpose of maintaining the voltage stability of the control point. The simulation results prove the feasibility and effectiveness of the strategy.

  1. Speed Control of Induction Motor by Using Variable Frequency

    OpenAIRE

    Drive Pooja Shinde; Rupali Burungale

    2014-01-01

    The variable speed drive is focused on voltage amplitude control. However, its only control speed in constraint limits. The load on Induction Motor is not constant & vary as per load requirement. so speed must be change as per load. If the supply voltage decreased motor torque also decreases, for maintaining same torque, slip decreases hence speed falls and motor speed is directly proportional to supply frequency, hence to maintain a speed, the supply V/F ratio must be vary ac...

  2. Learning from experiences with industrial electric drive systems

    Energy Technology Data Exchange (ETDEWEB)

    Jallouk, Philip A.; Liles, Charles D. [Power Systems Section, Engineering Technology Division, Oak Ridge National Laboratory ORNL, Oak Ridge, TN (United States)

    1998-04-01

    After defining the terms of reference, in Chapter 1 the principles of relevant electric motors and variable or adjustable speed drives (VSD or ASD) are outlined. The types of dominant importance (and the only ones consequently dealt with) are the squirrel cage AC induction motor and the electronic variable speed drive. The chapter concludes by reviewing the intended readership, which includes both management and technical people. Chapter 2 goes into more detail, first examining the barriers to acceptance of energy-efficient motors and systems, such as the structure of the OEM market. That apart, the major barriers are seen as customer concern with initial costs, lack of overall systems responsibility by those specifying motors, lack of technical information and expertise, and lack of adequate performance data. The chapter concludes by examining the national practices and programmes of CADDET member countries, considered in alphabetical order. The last country considered is the US, for which the information provided dwarfs that given for other countries. The major emphasis is on the US Motor Challenge Program. 21 refs.

  3. Simplified drive system models for power system transient studies in industrial plants

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Sannino, Ambra

    2007-01-01

    In order to simulate industrial plants for different power system transient studies, simplified adjustable speed drive (ASD) models are needed. For power system transient studies such as assessing the voltage dip ride-through capability of ASDs, detailed representation of semiconductor valve...... switching can be avoided, thereby making possible to increase the time step of the simulation. In this paper, simplified ASD models are developed and compared with corresponding detailed models. The performance of the simplified models is assessed when increasing the simulation step as much as possible...... while still maintaining the error within acceptable limits....

  4. Hybrid Switch Reluctance Drives For Pump Applications

    DEFF Research Database (Denmark)

    Jakobsen, Uffe

    The initial research problem is to investigate an alternative motor drive to the existing permanent magnet synchronous and brushless DC-motor drives for pump applications. A review of different motor types showed that a possible candidate for another low cost permanent magnet motor may be the sin......The initial research problem is to investigate an alternative motor drive to the existing permanent magnet synchronous and brushless DC-motor drives for pump applications. A review of different motor types showed that a possible candidate for another low cost permanent magnet motor may...... a stroke. The changes of speed controller output during a stroke, may give rise to undesired low frequency oscillations in the speed controller output. A time variant speed controller is presented in the thesis that does not suffer from these issues. Like the brushless DC-motor (BLDC) and the permanent...

  5. Digital control of electric drives

    CERN Document Server

    Koziol, R; Szklarski, L

    1992-01-01

    The electromechanical systems employed in different branches of industry are utilized most often as drives of working machines which must be fed with electric energy in a continuous, periodic or even discrete way. Some of these machines operate at constant speed, others require wide and varying energy control. In many designs the synchronous cooperation of several electric drives is required in addition to the desired dynamic properties. For these reasons the control of the cooperation and dynamics of electromechanical systems requires the use of computers.This book adopts an unusual approach

  6. Low-speed and High-torque Permanent Magnetic Motor Direct Drive System for Oil Field Workover%修井机用低速大转矩永磁电机直驱系统

    Institute of Scientific and Technical Information of China (English)

    张炳义; 刘博年; 冯桂宏; 丁宏龙

    2016-01-01

    传统油田修井机采用柴油机或异步电机驱动.柴油机驱动系统的工作效率低、能耗大、污染高.异步电机和减速箱组成的驱动系统的功率因数低、系统维护复杂、噪声大.永磁电机直驱系统具有结构简单,高效节能,系统维护简单,噪声低等优点,可以解决传统柴油机以及异步电机存在的问题.该系统还具有易于控制,运行稳定的优势.通过单星形与双串星形双绕组变换的方法实现电机的宽恒功率调速.采用特殊表贴式转子结构可以削弱电机转矩脉动.控制上采用闭环矢量控制来实现电机的平稳运行以及带载悬停等功能.%The traditional oil field workover adopts a diesel engine or asynchronous motor as the drive.The diesel engine driving system has low efficiency,high energy consumption and high pol-lution.The drive system of the induction motor with the gearbox has low power factor,system maintenance is complex and the noise is large.Permanent magnetic motor direct drive system has the advantages of simple structure,high efficiency and energy saving,system maintenance is sim-ple and the noise is low.Permanent magnetic motor direct drive system can solve the problem of traditional diesel engine and asynchronous machine.At the same time,the system also has the ad-vantages of easy control and stable operation.The wide range of constant power expansion of the motor is realized by using the transformation of single star winding and double star winding .The torque ripple of the motor can be reduced by using a special form of surface mounted rotor struc-ture.The closed-loop vector control is adopted to realize the stable running of the motor and the function of cease with load.

  7. 32 CFR 636.22 - Speed regulations.

    Science.gov (United States)

    2010-07-01

    .... (2) The authorized speed limit in the school zones is 15 miles per hour when any of the following conditions are present: (i) A school crossing attendant is present. (ii) Children are present in the area... MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving: Trails, 4...

  8. Algorithm of brush short-circuit coefficients of DC machines for extremely low speed drives%极低速驱动用直流电机电刷短路系数的算法

    Institute of Scientific and Technical Information of China (English)

    张琪; 谢国栋; 黄苏融

    2008-01-01

    When a direct-current (DC) machine runs at extremely low speed or standstill, the reduction in the armature resistance and the armature flux linkage due to the short circuited coils by the brushes on the commutator should not be neglected. Taking this reduction effect into account, the average values of the reduction coefficients relate to the machine parameters in complicated forms. In this paper, an effective algorithm for the precise computation of the average values of these reduction coefficients is proposed. Furthermore, in the algorithm, the effect of the insulation thickness between the commutator segments and the multiplicity of the wave winding are considered for the first time. The proposed algorithm can also be accommodated into the computer-aided design (CAD) of a DC machine, which normally runs at extremely low speed or standstill.

  9. Analysis on Toyota A761 E 6-speed Automatic Transmission Drive System%丰田A761E6速自动变速器传动系统研究

    Institute of Scientific and Technical Information of China (English)

    郑劲

    2014-01-01

    分析了6速A761E变速器组成和结构,绘制出了变速器的传动原理图,研究了变速器主要挡位的动力传动路线。%The composition and structure of six-speed transmission A761E were analyzed,the transmission schematics were mapped out, the power transmission lines of the transmission main gears were studied.

  10. China' s Optimal Foreign Reserves : Quantitative Characteristics, Motivation Decomposition and Adjustment Speed%中国最优外汇储备:数量特征、动机分解与调整速度

    Institute of Scientific and Technical Information of China (English)

    陈奉先; 邹宏元

    2012-01-01

    本文在非均衡框架下考察中国最优外汇储备数量特征并对持储动机进行静态和动态分解。结果发现:中国的实际和最优外汇储备量自2002年起陡增,但后者始终低于前者且二者缺口不断扩大;中国的最优外汇储备持有行为体现着交易性动机、预防性动机、重商主义动机和攀比动机,并受汇率因素影响;交易性动机和攀比动机对最优外汇储备持有行为的影响最大,预防性动机在2006年以后逐渐强化,重商主义动机和汇率因素的影响微弱;中国较低的储备缺口调整系数造成中国最优外汇储备量居高不下。外需拉动型的经济发展模式、强制结售汇制和汇率弹性不足则是导致储备缺口调整系数低下的重要原因。%This paper explores the quantitative characteristics of China' s optimal foreign reserves under disequilibrium framework and then decomposes reserve hoarding motivations in static and dynamic model. We find that:China' s actual and optimal foreign reserves are surging since 2002 with the later far below the former and their gap extending; China's accumulation of optimal foreign exchange reserves reveals the presence of transaction motivation, precautionary motivation, mercantilism motivation, competitive motivation and the influence of exchange rate volatility. The transaction motivation and competitive motivation are of the largest influence, and the precautionary motivation is of upward trending since 2006, while the mercantilism motivation and exchange rate factor are of weak influence; The lower adjustment coefficient λ finally leads to China' s high optimal foreign reserves. Export - oriented economic development mode, compulsory foreign exchange settlement regime and lack of foreign exchange rate flexibility lead to the lower adjustment coefficient λ.

  11. Tooth modification and dynamic performance of the cycloidal drive

    Science.gov (United States)

    Ren, Zhong-Yi; Mao, Shi-Min; Guo, Wen-Chao; Guo, Zheng

    2017-02-01

    A new method of cycloid disc tooth modification is presented in this paper. Its main idea is to design the modification clearance curves to adapt to different modification targets. A detailed procedure of the new modification clearance curve, which can be defined by adjusting the position of 5 key points is developed. Numerical experiments are carried out to verify the effectiveness of the new method. A Multi-DOF nonlinear dynamic model of cycloidal speed reducer is established, then the cycloid disc rotational displacement and rotational velocity versus time of different modification clearance are solved by the Runge-kutta numerical method. The results show that this method can improve the carrying capability of cycloidal drive, eliminate noise and vibration and develop the transmission accuracy.

  12. Speed mathematics

    CERN Document Server

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  13. Structural and acoustic noise radiated by CD drives

    NARCIS (Netherlands)

    Nijhof, Marten J.J.; Beltman, Willem M.

    2005-01-01

    Optical drives inside PCs operate at high speed, which may result in significant noise. These drives function both as airborne and structural vibration sources. Three main paths can be distinguished through which noise is emitted to the surroundings: (1) the vibrations of the front of the drive emit

  14. Active control system for high speed windmills

    Science.gov (United States)

    Avery, D.E.

    1988-01-12

    A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

  15. IMPLEMENTATION AND STUDY OF BLDC MOTOR DRIVE SYSTEM

    OpenAIRE

    2016-01-01

    The BLDC motor  is an electronically commutated dc motor becoming very popular in many applications. There are various speed control methods used for BLDC motor. The performance of BLDC motor drives can be improved using sensored control techniques over sensorless technology. This paper presents Brushless Direct Current motor drive system and its sensored speed control technique with PWM.  Advantages and limitations of sensorless techniques are reviewed and then, sensored speed cont...

  16. Speed checks on the CERN site

    CERN Multimedia

    2007-01-01

    In view of the significant number of speeding incidents that have been reported, CERN will shortly start to carry out speed checks on the site. The radar used for this purpose will show drivers the speed measured. The disciplinary measures taken against those exceeding the authorised limit (generally 50 k.p.h.) will include a ban from driving on the site for a minimum of one month. Maximilian Metzger
Secretary-General

  17. An Adjustable-speed System With Single-phase AC Input Based on Electrolytic Capacitor-less Tapped-inductor Single-stage Boost Inverters%单相交流输入的无电解电容抽头电感单级升压逆变器在交流调速系统中的应用

    Institute of Scientific and Technical Information of China (English)

    周玉斐; 黄文新; 赵健伍

    2014-01-01

    研究将无电解电容的单级升压逆变技术应用于变频调速系统。采用的抽头电感单级升压逆变器(tapped- inductor single-stage boost inverter,TISSBI)包含由1个抽头电感和2个二极管构成的无源网络,通过调节直通占空比和电感抽头的位置,能够实现单级升降压功能。将无电解电容的TISSBI应用于单相输入的变频调速系统,实现抗电网电压跌落、母线脉动抑制和提高输入功率因数的功能。用实验验证了理论分析方法的可行性。%This paper presented an adjustable-speed system with single-phase AC input based on the electrolytic capacitor-less single-stage boost inverter with tapped-inductor. The tapped-inductor single-stage boost inverter (TISSBI) includes an impedance network with one tapped inductor and two diodes, and it can realize buck or boost performance. In order to resist the grid voltage sags, output low frequency ripple decreasing, and input power factor improvement, this paper applied the electrolytic capacitor-less TISSBI to adjustable-speed system with single-phase AC input. Experimental results were carried out to verify the theoretical analysis.

  18. Naturalistic speeding data: Drivers aged 75 years and older

    Directory of Open Access Journals (Sweden)

    Anna Chevalier

    2016-09-01

    Full Text Available The data presented in this article are related to the research article entitled “A longitudinal investigation of the predictors of older drivers׳ speeding behavior” (Chevalier et al., 2016 [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75–94 years (median 80 years, 52% male living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.

  19. Naturalistic speeding data: Drivers aged 75 years and older.

    Science.gov (United States)

    Chevalier, Anna; Chevalier, Aran John; Clarke, Elizabeth; Wall, John; Coxon, Kristy; Brown, Julie; Ivers, Rebecca; Keay, Lisa

    2016-09-01

    The data presented in this article are related to the research article entitled "A longitudinal investigation of the predictors of older drivers׳ speeding behavior" (Chevalier et al., 2016) [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75-94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS) data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.

  20. DOES REGIONAL FISCAL BEHAVIOR DRIVE THE DYNAMIC ADJUSTMENT OF CHINA' S TRADE BALANCE%地方财政行为是否驱动了中国贸易收支的动态调整*--基于异质性动态调整模型的分析

    Institute of Scientific and Technical Information of China (English)

    林峰; 吴周恒

    2015-01-01

    本文利用1997—2013年中国省际层面的面板数据,借助异质性动态调整模型从动态视角考察了地方财政行为对中国贸易收支调整速度的影响。研究结果显示:(1)平均而言,在地方财政行为的驱动下,中国实际贸易收支向最优水平动态调整的速度约为0.045。总体表明,地方财政行为对中国贸易收支的驱动性影响较弱,引致实际贸易收支向最优水平调整的速度也较为缓慢。(2)财政支出分权的强化会制约贸易收支的调整速度,贸易收支调整呈现“相对惰性”。财政收入分权的提高和预算内财政支出的扩张能够加快实际贸易收支向最优贸易收支调整的速度,助力贸易收支实现平滑调整。预算外财政支出和财政收入的变化对调整速度则不会产生显著性影响。(3)贸易收支的调整速度呈现显著的区域异质性。本文的结论表明,现阶段中国要实现贸易收支的平衡调整路径,中央及地方政府必须把握好财政行为与贸易收支的动态联动关系。%Utilizing provincial panel data from 1997 to 2013,this paper constructs a heteroscedastic dynamic adj ustment model to test the impacts of regional fiscal behavior on the dynamic adj ustment of China’ s trade balance.The empirical results show as follows.Firstly,the adjustment speed of trade balance is nearly 0. 045 which driven by regional fiscal behavior.Obviously,the impact of regional fiscal behavior is somehow low.Secondly,both of fiscal revenue decentralization and extra-budgetary expendi-ture can increase adj ustment speed of trade balance.However,fiscal expenditure decentralization will re-duce adj ustment speed while fiscal revenue and budgetary expenditure exert no efforts on adj ustment speed.Thirdly,the effects of adjustment speed have significant regional heterogeneity.Therefore,China’ s dynamic coordinated development issues in terms of regional fiscal behavior

  1. Energy Optimal Control of Induction Motor Drives

    DEFF Research Database (Denmark)

    Abrahamsen, Flemming

    This thesis deals with energy optimal control of small and medium-size variable speed induction motor drives for especially Heating, Ventilation and Air-Condition (HVAC) applications. Optimized efficiency is achieved by adapting the magnetization level in the motor to the load, and the basic...... purpose is demonstrate how this can be done for low-cost PWM-VSI drives without bringing the robustness of the drive below an acceptable level. Four drives are investigated with respect to energy optimal control: 2.2 kW standard and high-efficiency motor drives, 22 kW and 90 kW standard motor drives....... The method has been to make extensive efficiency measurements within the specified operating area with optimized efficiency and with constant air-gap flux, and to establish reliable converter and motor loss models based on those measurements. The loss models have been used to analyze energy optimal control...

  2. Cannabis effects on driving longitudinal control with and without alcohol.

    Science.gov (United States)

    Hartman, Rebecca L; Brown, Timothy L; Milavetz, Gary; Spurgin, Andrew; Pierce, Russell S; Gorelick, David A; Gaffney, Gary; Huestis, Marilyn A

    2016-11-01

    Although evidence suggests cannabis impairs driving, its driving-performance effects are not fully characterized. We aimed to establish cannabis' effects on driving longitudinal control (with and without alcohol, drivers' most common drug combination) relative to psychoactive ∆(9) -tetrahydrocannabinol (THC) blood concentrations. Current occasional (≥1×/last 3 months, ≤3 days per week) cannabis smokers drank placebo or low-dose alcohol, and inhaled 500 mg placebo, low (2.9%), or high (6.7%) THC vaporized cannabis over 10 min ad libitum in separate sessions (within-subject, six conditions). Participants drove (National Advanced Driving Simulator, University of Iowa) simulated drives 0.5-1.3 h post-inhalation. Blood and breath alcohol samples were collected before (0.17 and 0.42 h) and after (1.4 and 2.3 h) driving. We evaluated the mean speed (relative to limit), standard deviation (SD) of speed, percent time spent >10% above/below the speed limit (percent speed high/percent speed low), longitudinal acceleration, and ability to maintain headway relative to a lead vehicle (headway maintenance) against blood THC and breath alcohol concentrations (BrAC). In N=18 completing drivers, THC was associated with a decreased mean speed, increased percent speed low and increased mean following distance during headway maintenance. BrAC was associated with increased SD speed and increased percent speed high, whereas THC was not. Neither was associated with altered longitudinal acceleration. A less-than-additive THC*BrAC interaction was detected in percent speed high (considering only non-zero data and excluding an outlying drive event), suggesting cannabis mitigated drivers' tendency to drive faster with alcohol. Cannabis was associated with slower driving and greater headway, suggesting a possible awareness of impairment and attempt to compensate. Copyright © 2016 John Wiley & Sons, Ltd.

  3. 超低速直流电机电刷短路系数计算%Computation of brush short-circuit coefficients of DC machines for extremely low speed drives

    Institute of Scientific and Technical Information of China (English)

    张琪; 谢国栋; 黄苏融

    2006-01-01

    Short circuit due to the brushes over the commutator segments of DC machines causes reduction in the armature resistance and flux linkage, which is especially meaningful when the electric machine is running at zero or extremely low speed. In design computation of DC machines, usually the average values of the coefficients are used in consideration of the effects of the short circuit.However, the average values have complicated relationships with the parameters of electric machines, therefore, no usable mathematical model has been established yet for precise computation. In this paper, a relatively simple and generalized method for precise computation of the average values of the short-circuit coefficients is proposed. This method decouples some of the machine parameters and, therefore establishes a highly parameterized mathematical model and is convenient in formulation for computation. In addition, the computation data for one and two brush pairs, which are the most common cases, is provided.

  4. The Speed Control of Diesel Generator Based on the SPWM Drive of Stepping Motor%基于步进电动机SPWM驱动的发电机调速控制

    Institute of Scientific and Technical Information of China (English)

    沈锐; 卢刚; 李声晋; 孟凡军

    2011-01-01

    Aiming at the narrow bound and sensitivity of a diesel generator accelerograph, the stepping motor was driven with SPWM method,which achieved the even speed control of the diesel generator between 700 r/min and 3 800 r/min. Experimentations validated the feasibility and accuracy of the design proposal and the dynamic response and general performance of the diesel generator were improved.%针对某柴油发电机油门调整范围窄而精度要求高的特点,以SPWM方式驱动油门调整用两相混合式步进电动机,实现了该柴油发电机在700~3 800 r/min内的平滑调速.实验验证了所设计方案的可行性,改善了柴油发电机的动态响应,提高了系统的综合性能.

  5. Highly efficient, gearless drive; Hocheffizienter, getriebeloser Antrieb

    Energy Technology Data Exchange (ETDEWEB)

    Niederer, R.

    2004-07-01

    Highly efficient, gearless variable-speed drive systems for low-speed applications have been developed. These systems consist of an inverter with active switches (IGBTs, MOSFETs, resp.) and a synchronous machine excited with permanent magnets. Therefore, these systems can be used for drive as well as for generator applications. They operate very efficiently since a gearbox is obsolete, furthermore weight, dimensions, noise and maintenance can be reduced. The inverter controllers do not require any speed sensors, thus reliability is increased and costs are decreased. Application for low-speed variable-speed drive systems can be found in industrial applications, cable railways or wind turbines. Both systems have been optimized in several iterative loops, in what regards overall efficiency and material expenditure. For both systems, prototypes have been developed and tested. Both prototypes performed reliably and fulfilled the expectations. The high power system (1200 kW, 20 rpm) operated at rated load with an overall efficiency of 93.1%, the lower power system (3 kW, 60 rpm) with an overall efficiency of 85%. Thus the losses of these new systems are at rated load about 4% lower compared to conventional drive systems equipped with a mechanical gearbox. (author)

  6. The effect of social marketing communication on safe driving.

    Science.gov (United States)

    Yang, Dong-Jenn; Lin, Wan-Chen; Lo, Jyue-Yu

    2011-12-01

    Processing of cognition, affect, and intention was investigated in viewers of advertisements to prevent speeding while driving. Results indicated that anchoring-point messages had greater effects on viewers' cognition, attitude, and behavioral intention than did messages without anchoring points. Further, the changes in message anchoring points altered participants' perceptions of acceptable and unacceptable judgments: a higher anchoring point in the form of speeding mortality was more persuasive in promoting the idea of reducing driving speed. Implications for creation of effective safe driving communications are discussed.

  7. Annual Adjustment Factors

    Data.gov (United States)

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  8. Development of a speeding-related crash typology.

    NARCIS (Netherlands)

    Council, F.M. Reurings, M. Srinivasan, R. Masten, S. & Carter, C.

    2010-01-01

    Speeding, the driver behaviour of exceeding the posted speed limit or driving too fast for conditions, has consistently been estimated to be a contributing factor to a significant percentage of fatal and nonfatal crashes. The U.S. Department of Transportation has instituted the Speed Management Stra

  9. Using Appropriate Speed Tables Regarding to the Speed Limit of Streets

    Directory of Open Access Journals (Sweden)

    Amir Falamarzi

    2014-04-01

    Full Text Available In the present decade along the increasing trend of using private vehicles, calming the local streets and residential areas has been important for local authorities. There are many unsuccessful experiences of traffic calming implementations because of lacking knowledge and engineered assessment before implementing them. Considering the design speed of traffic, calming measure is an essential factor to employ these measures. Design speed of different size of speed humps is investigated in previous studies because of its circular shape but for speed tables it is unknown. In this research the design speeds of two common speed tables in the city of Tehran have been examined, 6.5 and 8.5 m speed table. For calculating the design speed of the speed tables, we asked 220 drivers to participate in our experiment by installing a GPS tracker in their vehicles and encouraging them to drive normally. Crossing speeds over 6.5 and 8.5 m speed tables have been analyzed by collecting totally 220 samples. We pick out 100 correct samples for each speed table and the 85th percentile speed has been calculated for them, consequently the results of 85th percentile calculation of the crossing speeds have been proposed as the design speeds. For 6.5 m speed table, design speed is calculated 41.5 km/h and for 8.5 m speed table, design speed is calculated 47.5 km/h. the comparison of recent findings and past finding of 9.5 m speed table which is used in Denmark with a design speed of 80 km/h reveals that 1 m increasing with the length of a 6.5 speed table plateau will result 3 km/h increase in its design speed. The findings of this research can help traffic calming experts to take in consideration of the relation between speed table physical characteristics and its design speed. Furthermore by finding the design speed of speed tables, we can choose suitable speed tables for streets with different speed limits according to the design speed of speed tables.

  10. NOx emissions from Euro IV busses with SCR systems associated with urban, suburban and freeway driving patterns.

    Science.gov (United States)

    Fu, Mingliang; Ge, Yunshan; Wang, Xin; Tan, Jianwei; Yu, Linxiao; Liang, Bin

    2013-05-01

    NOx and particulate matter (PM) emissions from heavy-duty diesel vehicles (HDVs) have become the most important sources of pollutants affecting urban air quality in China. In recent years, a series of emission control strategies and diesel engine polices have been introduced that require advanced emission control technology. China and Europe mostly have used Selective Catalytic Reduction (SCR) with urea to meet the Euro IV diesel engine emission standard. In this study, two Euro IV busses with SCR were tested by using potable emission measurement system (PEMS) to assess NOx emissions associated with urban, suburban and freeway driving patterns. The results indicated that with the SCR system, the urea injection time for the entire driving period increased with higher vehicle speed. For freeway driving, the urea injection time covered 71%-83% of the driving period; the NOx emission factors from freeway driving were lower than those associated with urban and suburban driving. Unfortunately, the NOx emission factors were 2.6-2.8-, 2.3-2.7- and 2.2-2.3-fold higher than the Euro IV standard limits for urban, suburban and freeway driving, respectively; NOx emission factors (in g/km and g/(kW·h)) from the original vehicles (without SCR) were higher than their corresponding vehicles with SCR for suburban and freeway driving. Compared with the IVE model results, the measured NOx emission factors were 1.60-1.16-, 1.77-1.27-, 2.49-2.44-fold higher than the NOx predicted by the IVE model for urban and suburban driving, respectively. Thus, an adjustment of emission factors is needed to improve the estimation of Euro IV vehicle emissions in China.

  11. Risky driving and lifestyles in adolescence.

    Science.gov (United States)

    Bina, Manuela; Graziano, Federica; Bonino, Silvia

    2006-05-01

    Several studies have shown that risky driving is especially prevalent among young drivers and recent research has pointed out that driving in adolescence should be investigated in the more general context of adolescent development. The first aim of this contribution was to analyze involvement in risky driving in a normative sample of 645 Italian adolescents, boys and girls, aged 14-17, through a self-report questionnaire. A second aim was to evaluate the association between risky driving and lifestyle, defined as involvement in other health risk behaviors and leisure activities. The main results showed that many adolescents drove cars and motorcycles without the required driving license and the most frequent offences were speeding and failure to maintain a safe braking distance. Gender and age differences were also investigated. Results concerning the association between risky driving and lifestyle showed that risky driving was not an isolated behavior. Boys who displayed risky driving practices were more likely to adopt a lifestyle characterized by high involvement in antisocial behaviors, tobacco smoking, comfort eating and time spent in non-organized activities with friends. Girls involved in risky driving were more likely to be involved in other risk-taking behaviors, antisocial behaviors and drug use.

  12. The dynamic running law study on driving system of hydraulic winder

    Institute of Scientific and Technical Information of China (English)

    彭佑多; 刘德顺; 郭迎福; 张永忠; 文西芹

    2002-01-01

    Dynamic running law of the hydraulic driving system decides the hoisting cage velocity curve in a hoisting cycle and is decided by the characteristic of the hydraulic driving system and by the operating speed of hoist driver. The paper studies the dynamic running law of hydraulic driving system, analyses the influence of driver operating speed on the dynamic running characteristic, and points out the reasonable driver operating speed to control the dynamic stress in rope and to reduce the oscillation of rope system.

  13. Approach to Developing Predictive Capability for Hohlraum Drive and Symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Jones, O. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-22

    Currently, we do not have the ability to predict the hohlraum drive and symmetry without requiring ad hoc adjustments to physics models. This document describes a plan for code improvements and focused physics validation experiments.

  14. HARMONIC DRIVE SELECTION

    Directory of Open Access Journals (Sweden)

    Piotr FOLĘGA

    2014-03-01

    Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

  15. Apparent speed increases at low luminance

    OpenAIRE

    Vaziri-Pashkam, Maryam; Cavanagh, Patrick

    2008-01-01

    To investigate the effect of luminance on apparent speed, subjects adjusted the speed of a low-luminance rotating grating (0.31 cd/m2) to match that of a high-luminance one (1260 cd/m2). Above 4 Hz, subjects overestimated the speed of the low-luminance grating. This overestimation increased as a function of temporal rate and reached 30% around 10 Hz temporal rates. The speed overestimation became significant once the lower luminance was 2.4 log units lower than the high luminance comparison. ...

  16. KrF激光对高速飞片的驱动特性研究%Research on the driving characteristics of high speed flyer using KrF laser

    Institute of Scientific and Technical Information of China (English)

    李业军; 王钊; 田宝贤; 梁晶; 韩茂兰; 陆泽; 汤秀章

    2014-01-01

    利用诱导空间非相干技术平滑的KrF准分子(248nm)激光驱动带有烧蚀层的平面靶,研究激光空间均匀性对产生完整飞片的影响,结果表明激光不均匀性在2%以下,能够产生完整的高速飞片,且完整飞片能够维持20ns以上不破裂;当激光不均匀性达到5%,激光引入流体力学不稳定性种子应很强,冲击波在靶内输运过程中不稳定性不断发展增强,到靶背时强到足以使飞片解体甚至气化,不能产生完整的飞片。为了获得尽可能高的飞片速度,采用激光与烧蚀层参数不匹配方法,使冲击波对飞片作多次加速。利用功率密度为1012 W/cm2的KrF激光与含50μm Kapton烧蚀层的5μm铝飞片作用,得到速度约10km/s的高速飞片,与模拟结果吻合得很好。%KrF excimer laser (248nm)has high spatial uniformity by using induced spatial in-coherence technology.After image relay and amplification by optical angular multiplexing tech-nology,non-uniformity of image surface of focal spot is 1 .6%.The spot spatial uniformity decreases with increasing distance of deviating image surface,the spatial non-uniformity is up to 5% at 3mm place deviating image surface.Laser directly drives planar target with ablation layer, the effects of laser spatial uniformity on flyer planarity and integrity were investigated.The results show when the non-uniformity of laser is below 2%,the integrity of inference fringes measured by laser velocity interferometer system for reflector keeps very well,the inference frin-ges last about 20ns after fringes jump.And the flyer can fly about 150 microns.The roughness of discontinuity is 62ps,which indicates that the shock wave planarity is good.The target debris deposited on sputtering film from the target of about 120mm is larger particles,which confirms the flyer has better integrity.When the laser non-uniformity is 5%,the interference fringes dis-appear completely after fringes jump

  17. EMI performance comparison of two-level and three-level inverters in small dc-link capacitors based motor drives

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, S.

    2012-01-01

    The size of passive components in an adjustable speed drive can be reduced by using small dc-link capacitors. The EMI filter in the drive also consists of passive components. The size of the filter can be reduced by using a three-level inverter, which can have low output voltage distortion. However......, the three-level inverter based on small dc-link capacitors requires a PWM strategy to maintain neutral-point voltage balance. In this paper, the common mode voltage, which is the determining factor for the EMI filter size, is analyzed for a virtual-vector-based PWM strategy. The common mode voltage....... Results show that the conducted emission from the three-level inverter is lower than that of the two-level inverter. Thus, a three-level inverter requires a smaller EMI filter in motor drives with small dc-link capacitors....

  18. Improvement on Transportation Safety on Bus by Installing A Speed Limiter in Conventional Engine to Reduce Speed Rate

    Directory of Open Access Journals (Sweden)

    Pranoto Hadi

    2016-01-01

    Full Text Available Driving is one of the conditions when the driver should be given special attention to make the motor vehicle in driving way and the driver should be in a good condition. However, the problem is in a certain condition the driver lost their control speed due to their target and minimize the driving time and it led the high potential to accident. Therefore, speed limiter which applied in the bus is urgently needed to reduce the accident and improve their awareness of road safety. Developed speed limiter is completed by fuel cut-off system to prevent the engine and maintain the speed. Limitation of speed be adapted by government regulation. From the results show that the highest and average speed of 136 km/h and 123.5 km/h is observed by bus speed prior to use speed limiter. After speed limiter applied in the bus, the approved maximum speed is 90 km/h. Those data approve that the speed limiter can reduce 83% from the top speed before speed limiter applied.

  19. Inertial drives for micro- and nanorobots: two novel mechanisms

    Science.gov (United States)

    Zesch, Wolfgang; Buechi, Roland; Codourey, Alain; Siegwart, Roland Y.

    1995-12-01

    In micro or nanorobotics, high precision movement in two or more degrees of freedom is one of the main problems. Firstly, the positional precision has to be increased (Nanorobot Project, two new piezoelectric devices have been developed. `Abalone' is a 3-dof system that relies on the impact drive principle. The 38 mm X 33 mm X 9 mm slider can be moved to each position and orientation in a horizontal plane within a theoretically infinite workspace. In the stepping mode it achieves a speed of 1 mm/s in translation and 7 deg/s in rotation. Within the actuator's local range of 6 micrometers fine positioning is possible with a resolution better than 10 nm. `NanoCrab' is a bearingless rotational micromotor relying on the stick-slip effect. This 10 mm X 7 mm X 7 mm motor has the advantage of a relatively high torque at low rotational speed and an excellent runout. While the maximum velocity is 60 rpm, it reaches its highest torque of 0.3 mNm at 2 rpm. Another benefit is the powerless holding torque of 0.9 mNm. With a typical step of 0.1 mrad and a local resolution 3 orders of magnitude better than the step angle, NanoCrab can be very precisely adjusted. Design and measurements of the characteristics of these two mechanisms will be presented and compared with the theoretical analysis of inertial drives presented in a companion paper. Finally their integration into the Nanorobot system will be discussed.

  20. Homogeneity Adjustment of Annual Mean Wind Speed and Elementary Calculation of Fundamental Wind Pressure over Xinjiang Meteorological Stations%新疆气象站年均风速均一化订正与基本风压估算初探

    Institute of Scientific and Technical Information of China (English)

    辛渝; 陈洪武; 李元鹏; 陈鹏翔; 余行杰; 王铁

    2012-01-01

    In order to develop detail survey and integrative evaluation of wind energy resource, the consistency corrections, objective homogeneity tests (such as SNHT, Potter, and CUSUM), and homogeneity adjustment of yearly mean wind speed series were carried out during 1970 - 2009 from four meteorological stations which represent wind areas according to their historical metadata features. During the period of non-automatic wind recorder, how to build the 10-tnin interval yearly maximum wind velocity series was also explored elementarily based on observed 2-min interval wind data. The results show as follows: 1) The yearly mean wind speed time series were inhomoge-neons, which was caused by the change of their surroundings or other uncertain factors at Burqin, Naomaohu, and Hongliuhe stations. From the values of the SNHT homogeneity adjustment and the buildings surrounding the stations, the most largely environment influence occurred at Burqin station where the time series broke off three times and the mean accumulated adjustment value reaches 0. 9 m · s-1 or so. There are two discontinuous points at Naomaohu station, one of which concerns location moving, and that of adjustment value is 0. l~0. 2 m · s-1. There exists one discontinuous point at Hongliuhe station, which also concerns location moving like Naomaohu station, and that of adjustment value is 0.1 - 0. 2 m · s-1. 2) On transforming the yearly maximum wind velocity of 10-min interval from that of observed 2-min interval under the control of some critical wind speed, it is acceptable to adopt the experiential formula fitting to the northwestern part of China at Shisanjianfang station, while it is better to employ their mean portion correlation at the other three stations.%为了较好地开展风能资源的详查与综合评价工作,根据新疆各风区挑选的参照站历史风况资料序列特点,在参考测站历史“元数据”直接进行非均一性检验与一致性订正基础上,对其中4

  1. OVER SPEED VIOLATION MANAGEMENT OF A VEHICLE THROUGH ZIGBEE

    OpenAIRE

    Uma Makeswari.A; Rubini.R

    2013-01-01

    In the present day scenario traffic rules are frequently violated by the drivers and over speeding occur due to bad driving behavior. So, a driver assistance system is provided to prevent over speeding,violation of road rules and also to display alert messages. The proposed system has an alerting, recording and reporting system for over speed violation management. The Zigbee transmitter sends the speed limit of the particular lane entered by the vehicle and also gives alerts like “road works”...

  2. Optimal Control Development System for Electrical Drives

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2008-08-01

    Full Text Available In this paper the optimal electrical drive development system is presented. It consists of both electrical drive types: DC and AC. In order to implement the optimal control for AC drive system an Altivar 71 inverter, a Frato magnetic particle brake (as load, three-phase induction machine, and dSpace 1104 controller have been used. The on-line solution of the matrix Riccati differential equation (MRDE is computed by dSpace 1104 controller, based on the corresponding feedback signals, generating the optimal speed reference for the AC drive system. The optimal speed reference is tracked by Altivar 71 inverter, conducting to energy reduction in AC drive. The classical control (consisting of rotor field oriented control with PI controllers and the optimal one have been implemented by designing an adequate ControlDesk interface. The three-phase induction machine (IM is controlled at constant flux. Therefore, the linear dynamic mathematical model of the IM has been obtained. The optimal control law provides transient regimes with minimal energy consumption. The obtained solution by integration of the MRDE is orientated towards the numerical implementation-by using a zero order hold. The development system is very useful for researchers, doctoral students or experts training in electrical drive. The experimental results are shown.

  3. Stability Analysis of BLDC Motor Drive based on Input Shaping

    Directory of Open Access Journals (Sweden)

    M.Murugan

    2013-10-01

    Full Text Available The main objective of this work is to analyze the brushless DC (BLDC motor drive system with input shaping using classical control theory. In this paper, different values of damping ratio are used to understand the generalized drive performance. The transient response of the BLDC motor drive system is analyzed using time response analysis. The dynamic behaviour and steady state performance of the BLDC motor drive system is judged and compared by its steady state error to various standard test signals. The relative stability of this drive system is determined by Bode Plot. These analysis spotlights that it is possible to obtain a finite-time setting response without oscillation in BLDC motor drive by applying input in four steps of different amplitude to the drive system. These analyses are helpful to design a precise speed control system and current control system for BLDC motor drive with fast response. The Matlab/Simulink software is used to perform the simulation.

  4. Control Scheme of Z-Source Inverter Based BLDC Motor Drive System Using Modified Pulse Width Modulation Techniq

    Directory of Open Access Journals (Sweden)

    S. Suresh Kumar,

    2014-01-01

    Full Text Available A modified pulse width modulation technique for Z-source inverter based BLDC motor is proposed and analyzed in this project.The Z-source inverter can be used as Buck/Boost converter with lower cost and high efficiency. BLDC motors are used in electric vehicles where portability and efficiency are required. This drive system provides advantages of both BLDC motors and Z-source inverter, and can be used in fuel cell system and other adjustable speed drive application. In this project principle of modified pulse width modulation technique is implemented and simulated. The model of a three phase Z-source inverter has been discussed based on modified pulse with modulation technique. The simulation of Z-source inverter based BLDC motor is done using the MATLAB/SIMULINK.

  5. Design of a Sustainable and Efficient Transportation Station (SETS Based on Renewable Sources and Efficient Electric Drives

    Directory of Open Access Journals (Sweden)

    Myungchin Kim

    2016-12-01

    Full Text Available The need for reduction in power consumption for public facilities has increased after the occurrences of multiple blackout events. In an effort to enable the development of green and smart social infrastructure, this paper introduces a design for a sustainable and efficient transportation system (SETS. For this design, renewable power sources and efficient electric drives are considered to be crucial technologies. Considering the subway station as an illustrative example, a power system design that uses wind and solar energy as major power sources is studied. The adjustable speed electric drive system that uses synchronous reluctance machines for ventilation systems contributes to increasing the overall power consumption efficiency. The effectiveness of the proposed SETS system is verified through a set of various field measurement data and simulation results. While the verification results demonstrate that operation of SETS is enabled by effective integration of renewable sources and efficient ventilation systems, future research directions have also been identified.

  6. Adaptive control schemes for improving dynamic performance of efficiency-optimized induction motor drives.

    Science.gov (United States)

    Kumar, Navneet; Raj Chelliah, Thanga; Srivastava, S P

    2015-07-01

    Model Based Control (MBC) is one of the energy optimal controllers used in vector-controlled Induction Motor (IM) for controlling the excitation of motor in accordance with torque and speed. MBC offers energy conservation especially at part-load operation, but it creates ripples in torque and speed during load transition, leading to poor dynamic performance of the drive. This study investigates the opportunity for improving dynamic performance of a three-phase IM operating with MBC and proposes three control schemes: (i) MBC with a low pass filter (ii) torque producing current (iqs) injection in the output of speed controller (iii) Variable Structure Speed Controller (VSSC). The pre and post operation of MBC during load transition is also analyzed. The dynamic performance of a 1-hp, three-phase squirrel-cage IM with mine-hoist load diagram is tested. Test results are provided for the conventional field-oriented (constant flux) control and MBC (adjustable excitation) with proposed schemes. The effectiveness of proposed schemes is also illustrated for parametric variations. The test results and subsequent analysis confer that the motor dynamics improves significantly with all three proposed schemes in terms of overshoot/undershoot peak amplitude of torque and DC link power in addition to energy saving during load transitions.

  7. Modeling and Performance Prediction of Induction Motor Drive System for Electric Drive Tracked Vehicles

    Institute of Scientific and Technical Information of China (English)

    CHEN Shu-yong; CHEN Quan-shi; SUN Feng-chun

    2007-01-01

    The principle of rotor flux-orientation vector control on 100/150 kW three-phase AC induction motor for electric drive tracked vehicles is analyzed, and the mathematic model is deduced. The drive system of induction motor is modeled and simulated by Matlab/Simulink. The characteristics of motor and drive system are analyzed and evaluated by practical bench test. The simulation and bench test results show that the model is valid, and the driving control system has constant torque under rated speed, constant torque above rated speed, widely variable speed range and better dynamic characteristics. In order to evaluate the practical applications of high power induction motor driving system in electric drive tracked vehicles, a collaborative simulation based on interface technology of Matlab/Simulink and multi-body dynamic analysis software known as RecurDyn is done, the vehicle performances are predicted in the acceleration time (0-32 km/h) and turning characteristic (v=10 km/h, R=B).

  8. Development of Traction Drive Motors for the Toyota Hybrid System

    Science.gov (United States)

    Kamiya, Munehiro

    Toyota Motor Corporation developed in 2005 a new hybrid system for a large SUV. This system included the new development of a high-speed traction drive motor achieving a significant increase in power weight ratio. This paper provides an overview of the hybrid system, discusses the characteristics required of a traction drive motor, and presents the technologies employed in the developed motor.

  9. Effects of Yaw Motion on Driving Behaviour, Comfort and Realism

    NARCIS (Netherlands)

    Hogema, J.H.; Wentink, M.; Bertollini, G.P.

    2012-01-01

    The use of large displacement yaw cueing is becoming more common as a part of the motion cueing in driving simulators. It is expected that driving behaviour, comfort and realism will be positively affected by adding a yaw table, especially during low-speed turning manoeuvres. We used TNO's advanced

  10. Benchmarking judgmentally adjusted forecasts

    NARCIS (Netherlands)

    Ph.H.B.F. Franses (Philip Hans); L.P. de Bruijn (Bert)

    2015-01-01

    markdownabstractMany publicly available macroeconomic forecasts are judgmentally-adjusted model-based forecasts. In practice usually only a single final forecast is available, and not the underlying econometric model, nor are the size and reason for adjustment known. Hence, the relative weights give

  11. ADJUSTABLE CHIP HOLDER

    DEFF Research Database (Denmark)

    2009-01-01

    An adjustable microchip holder for holding a microchip is provided having a plurality of displaceable interconnection pads for connecting the connection holes of a microchip with one or more external devices or equipment. The adjustable microchip holder can fit different sizes of microchips...

  12. PERFORMANCE OF ANN BASED INDIRECT VECTOR CONTROL INDUCTION MOTOR DRIVE

    Directory of Open Access Journals (Sweden)

    A. K. Sharma,

    2007-09-01

    Full Text Available Indirect field orientation (IFO induction machine drives are increasingly employed in industrial drive systems, but the drive performance is often degrades. Motor works on best performance at certain voltage and frequency for certain loads. In this paper artificial neural network is used to predict the operating voltage and frequency when the load torque and speed going changed so motor efficiency is increased. Simulation and experimental results are shown to validate the scheme.

  13. Distractions in Everyday Driving

    Science.gov (United States)

    ... and more states banning handheld phone usage and texting while driving, and new technologies being developed to lock keypads ... made about texting. And you’re right, because texting while driving combines all three types of these distractions. When ...

  14. Driving After a Stroke

    Science.gov (United States)

    ... Inspirational Stories Stroke Heroes Among Us Driving After Stroke Updated:Jul 23,2015 Can I drive after ... more tips for daily living . Let's Talk About Stroke Fact Sheets Our stroke fact sheets cover treatments, ...

  15. Dementia and driving

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000028.htm Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia , deciding when they can no longer drive may ...

  16. Compression Ratio Adjuster

    Science.gov (United States)

    Akkerman, J. W.

    1982-01-01

    New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.

  17. Gear bearing drive

    Science.gov (United States)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  18. Effects of weather conditions, light conditions, and road lighting on vehicle speed.

    Science.gov (United States)

    Jägerbrand, Annika K; Sjöbergh, Jonas

    2016-01-01

    Light conditions are known to affect the number of vehicle accidents and fatalities but the relationship between light conditions and vehicle speed is not fully understood. This study examined whether vehicle speed on roads is higher in daylight and under road lighting than in darkness, and determined the combined effects of light conditions, posted speed limit and weather conditions on driving speed. The vehicle speed of passenger cars in different light conditions (daylight, twilight, darkness, artificial light) and different weather conditions (clear weather, rain, snow) was determined using traffic and weather data collected on an hourly basis for approximately 2 years (1 September 2012-31 May 2014) at 25 locations in Sweden (17 with road lighting and eight without). In total, the data included almost 60 million vehicle passes. The data were cleaned by removing June, July, and August, which have different traffic patterns than the rest of the year. Only data from the periods 10:00 A.M.-04:00 P.M. and 06:00 P.M.-10:00 P.M. were used, to remove traffic during rush hour and at night. Multivariate adaptive regression splines was used to evaluate the overall influence of independent variables on vehicle speed and nonparametric statistical testing was applied to test for speed differences between dark-daylight, dark-twilight, and twilight-daylight, on roads with and without road lighting. The results show that vehicle speed in general depends on several independent variables. Analyses of vehicle speed and speed differences between daylight, twilight and darkness, with and without road lighting, did not reveal any differences attributable to light conditions. However, vehicle speed decreased due to rain or snow and the decrease was higher on roads without road lighting than on roads with lighting. These results suggest that the strong association between traffic accidents and darkness or low light conditions could be explained by drivers failing to adjust their

  19. Speed Regulator for Permanent Magnet DC Boring Machine

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper a variable-speed system for a loaded permanent magnet direct current boring machine (PMDCBM) is described in details. The voltage adjustment of PMDCBM is accomplished by means of solid state switch with a high gain Darlington transistor. The device designed possesses good variable speed characteristic and Iow loss at low speed. The speed can be regulated automatically to hold at an ideal value according to the load.

  20. DYNAMIC DESIGN OF VARIABLE SPEED PLANAR LINKAGES

    Institute of Scientific and Technical Information of China (English)

    Yao Yanan; Yan Hongsen; Zou Huijun

    2005-01-01

    A method for improving dynamic characteristics of planar linkages by actively varying the speed function of the input link is presented. Design criteria and constraints for the dynamic design of variable speed planar linkages are developed. Both analytical and optimization approaches for determining suitable input speed functions to minimize the driving torque, the shaking moment, or both simultaneously of planar linkages, subject to various design requirements and constraints, are derived.Finally, some examples are given to illustrate the design procedure and to verify its feasibility.

  1. Optimal Driving of Large Belt Conveyor with Multi-roller Variable-Frequency Drive

    Institute of Scientific and Technical Information of China (English)

    FU Jun-qing; WANG Cong; LI Yu-jin

    2004-01-01

    in this paper, an electromechanically coupled mathematic model of multi-roller driving system for belt conveyor is set up, and the computing equations for dynamic displacement and dynamic tension of the conveyor are also formulated when the hoister is used for straining. Based on the belt conveyor of main inclined shaft in Chengzhuang coal mine, the driving torque, driving power and starting-speed characteristic of each electric motor are studied and measured when multi-roller variable-frequency drive (power distribution 2∶1) is used. The optimal control and the optimal starting-acceleration of the multi-roller variable-frequency drive are determined by a large number of industrial experiments and theoretical calculations.

  2. Driving speed on thoroughfares in minor towns in Denmark

    DEFF Research Database (Denmark)

    Jørgensen, Morten; Agerholm, Niels; Lahrmann, Harry;

    Sammenhængen mellem trafikulykker og hastighed viser, at øget hastighed resulterer i flere og mere alvorlige trafikulykker. Tidligere undersøgelser har indikeret, at bilister overskrider hastighedsgrænsen på gennemfartsveje i mindre byer i Danmark. For at holde farten nede i bygennemfarter er der...

  3. Reduced Input Throw and High-speed Driving

    Science.gov (United States)

    2007-08-08

    controllers were used in the experiment: a Momo Force (Logitech, Fremont, CA) mini-steering wheel, and a MSI Military Grade 5-3-G5831 Yoke (Measurement...transition, recovery, steady state), and their interaction. Additionally two controllers (an MSI yoke and a MOMO limited throw steering wheel) were...interaction. The controller main effect revealed a small but significant improvement of the MSI yoke (0.52 ± .05) over the Momo wheel (0.58 ± .05

  4. High performance AC drives

    CERN Document Server

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  5. Intelligent Speed Adaptation for involuntary drivers

    DEFF Research Database (Denmark)

    Agerholm, Niels; Tradisauskas, Nerius; Juhl, Jens

    2012-01-01

    The Danish Intelligent Speed Adaptation (ISA) trial ISA C included 26 commercial cars and 51 drivers a number of whom were involuntary. After a baseline period, ISA was activated for one year. The drivers should identify themselves with a personal key ID before driving. As well as being informative...

  6. STRESS; THE VULNERABILITY AND ASSOCIATION WITH DRIVING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    B. M.T. Shamsul

    2014-01-01

    Full Text Available Several factors may contribute to occurrence of road accidents which are human factors, vehicle factor, road factor and environmental factor. There has been recent evidence of a relationship between road accidents and emotional distress as well as fatigue. Monotonous and complex road environments are the road factor that relates to the internal factor within driver. The overall aim of this study was to compare driving stress, fatigue and driving error between complex and monotonous driving. This experimental study was carried out to measure the stress level, fatigue status and driving performance among hundred male drivers (20-59 years with driving experience more than one year. Cortisol concentration from respondents’ saliva was obtained to measure the stress level due to the driving test. Cortisols were measured using Salimetrics cortisol Enzyme Immunoassay kit (ELISA. Fatigue status was measured by using EEG test to the respondents while conducted the simulator driving test. Driving performance was measured based on the recorded data of Running-of-the Roads (RORI and Large Speed Variation (LSV index from the simulator system. This study found that there was a significant difference (p<0.05 between cortisol levels, EEG value and driving errors of monotonous and complex driving. Salivary cortisol level was found higher during monotonous driving compared to complex driving. Theta wave which indicates sleepy and fatigue condition was found higher on monotonous driving compared to other brainwaves which is alpha and beta state. RORI and LSV index was higher recorded during driving in complex road environments. The main implications of this study for road safety shows that monotonous driving had significantly induced driving stress and fatigue while complex driving lead to higher driving errors. Human factors and road factors could possibly put drivers in a higher risk to be involved in road accidents.

  7. A novel robust speed controller scheme for PMBLDC motor.

    Science.gov (United States)

    Thirusakthimurugan, P; Dananjayan, P

    2007-10-01

    The design of speed and position controllers for permanent magnet brushless DC motor (PMBLDC) drive remains as an open problem in the field of motor drives. A precise speed control of PMBLDC motor is complex due to nonlinear coupling between winding currents and rotor speed. In addition, the nonlinearity present in the developed torque due to magnetic saturation of the rotor further complicates this issue. This paper presents a novel control scheme to the conventional PMBLDC motor drive, which aims at improving the robustness by complete decoupling of the design besides minimizing the mutual influence among the speed and current control loops. The interesting feature of this robust control scheme is its suitability for both static and dynamic aspects. The effectiveness of the proposed robust speed control scheme is verified through simulations.

  8. 77 FR 52252 - Defense Federal Acquisition Regulation Supplement: Inflation Adjustment of Threshold for...

    Science.gov (United States)

    2012-08-29

    ...-related dollar thresholds subject to inflation adjustment in accordance with the requirements of 41 U.S.C... Regulation Supplement: Inflation Adjustment of Threshold for Acquisition of Right-Hand Drive Passenger Sedans... Authorization Act for Fiscal Year 2012 that requires adjustment of the statutory dollar limitation on...

  9. A 7-year dataset for driving and evaluating snow models at an Arctic site (Sodankylä, Finland)

    Science.gov (United States)

    Essery, Richard; Kontu, Anna; Lemmetyinen, Juha; Dumont, Marie; Ménard, Cécile B.

    2016-06-01

    Datasets derived from measurements at Sodankylä, Finland, for driving and evaluating snow models are presented. This is the first time that such complete datasets have been made available for a site in the Arctic. The continuous October 2007-September 2014 driving data comprise all of the meteorological variables required as inputs for physically based snow models at hourly intervals: incoming solar and longwave radiation, snowfall and rainfall rates, air temperature, humidity, wind speed and atmospheric pressure. Two versions of the driving data are provided: one using radiation and wind speed measurements made above the height of the trees around the clearing where the evaluation data were measured and one with adjustments for the influence of the trees on conditions close to the ground. The available evaluation data include automatic and manual measurements of bulk snow depth and snow water equivalent, and profiles of snow temperature, snow density and soil temperature. A physically based snow model is driven and evaluated with the datasets to illustrate their utility. Shading by trees is found to extend the duration of both modelled and observed snow cover on the ground by several days a year.

  10. Family Adjustment to Aphasia

    Science.gov (United States)

    ... Public / Speech, Language and Swallowing / Disorders and Diseases Family Adjustment to Aphasia Richard S. was a senior manager ... It also presents a great challenge to the family. There may be tension among family members and ...

  11. Semiclassical instability of dynamical warp drives

    CERN Document Server

    Finazzi, Stefano; Barceló, Carlos

    2009-01-01

    Warp drives are very interesting configurations in General Relativity: At least theoretically, they provide a way to travel at superluminal speeds, albeit at the cost of requiring exotic matter to exist as solutions of Einstein's equations. However, even if one succeeded in providing the necessary exotic matter to build them, it would still be necessary to check whether they would survive to the switching on of quantum effects. Semiclassical corrections to warp-drive geometries have been analyzed only for eternal warp-drive bubbles traveling at fixed superluminal speeds. Here, we investigate the more realistic case in which a superluminal warp drive is created out of an initially flat spacetime. First of all we analyze the causal structure of eternal and dynamical warp-drive spacetimes. Then we pass to the analysis of the renormalized stress-energy tensor (RSET) of a quantum field in these geometries. While the behavior of the RSET in these geometries has close similarities to that in the geometries associate...

  12. Remotely Adjustable Hydraulic Pump

    Science.gov (United States)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  13. Predicting drowsy driving in real-time situations: Using an advanced driving simulator, accelerated failure time model, and virtual location-based services.

    Science.gov (United States)

    Wang, Junhua; Sun, Shuaiyi; Fang, Shouen; Fu, Ting; Stipancic, Joshua

    2017-02-01

    This paper aims to both identify the factors affecting driver drowsiness and to develop a real-time drowsy driving probability model based on virtual Location-Based Services (LBS) data obtained using a driving simulator. A driving simulation experiment was designed and conducted using 32 participant drivers. Collected data included the continuous driving time before detection of drowsiness and virtual LBS data related to temperature, time of day, lane width, average travel speed, driving time in heavy traffic, and driving time on different roadway types. Demographic information, such as nap habit, age, gender, and driving experience was also collected through questionnaires distributed to the participants. An Accelerated Failure Time (AFT) model was developed to estimate the driving time before detection of drowsiness. The results of the AFT model showed driving time before drowsiness was longer during the day than at night, and was longer at lower temperatures. Additionally, drivers who identified as having a nap habit were more vulnerable to drowsiness. Generally, higher average travel speeds were correlated to a higher risk of drowsy driving, as were longer periods of low-speed driving in traffic jam conditions. Considering different road types, drivers felt drowsy more quickly on freeways compared to other facilities. The proposed model provides a better understanding of how driver drowsiness is influenced by different environmental and demographic factors. The model can be used to provide real-time data for the LBS-based drowsy driving warning system, improving past methods based only on a fixed driving.

  14. Weighted triangulation adjustment

    Science.gov (United States)

    Anderson, Walter L.

    1969-01-01

    The variation of coordinates method is employed to perform a weighted least squares adjustment of horizontal survey networks. Geodetic coordinates are required for each fixed and adjustable station. A preliminary inverse geodetic position computation is made for each observed line. Weights associated with each observed equation for direction, azimuth, and distance are applied in the formation of the normal equations in-the least squares adjustment. The number of normal equations that may be solved is twice the number of new stations and less than 150. When the normal equations are solved, shifts are produced at adjustable stations. Previously computed correction factors are applied to the shifts and a most probable geodetic position is found for each adjustable station. Pinal azimuths and distances are computed. These may be written onto magnetic tape for subsequent computation of state plane or grid coordinates. Input consists of punch cards containing project identification, program options, and position and observation information. Results listed include preliminary and final positions, residuals, observation equations, solution of the normal equations showing magnitudes of shifts, and a plot of each adjusted and fixed station. During processing, data sets containing irrecoverable errors are rejected and the type of error is listed. The computer resumes processing of additional data sets.. Other conditions cause warning-errors to be issued, and processing continues with the current data set.

  15. Omnidirectional Active Vision for Evolutionary Car Driving

    OpenAIRE

    2006-01-01

    We describe a set of simulations to evolve omnidirectional active vision, an artificial retina scanning over images taken via an omnidirectional camera, being applied to a car driving task. While the retina can immediately access features in any direction, it is asked to select behaviorally-relevant features so as to drive the car on the road. Neural controllers which direct both the retinal movement and the system behavior, i.e., the speed and the steering angle of the car, are tested in thr...

  16. Lectures on magnetohydrodynamical drives

    Science.gov (United States)

    Loigom, Villem

    The paper deals with nonconventional types of electrical machines and drives - magnetohydrodynamical (MHD) machines and drives. In cardinal it is based on the research conducted with participation of the author in Tallinn Technical University at the Institute of Electrical Drives and Power Electronics, where the use of magnetohydrodynamical motors and drives in the metallurgical and casting industries have been studied for a long time. Major research interests include the qualities and applications of the induction MHD-drives for set in the motion (pumping, turning, dosing, mixing, etc.) non-ferrous molten metals like Al, Mg, Sn, Pb, Na, K, and their alloys. The first part of the paper describes induction MHD motors and their electrohydraulical qualities. In the second part energy conversion problems are described. Also, on the basis of the analogy between electromechanical and electrohydraulical phenomenas, static and dynamic qualities of MHD drives with induction MHD machines are discussed.

  17. Universal Drive Train Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  18. High speed data converters

    CERN Document Server

    Ali, Ahmed MA

    2016-01-01

    This book covers high speed data converters from the perspective of a leading high speed ADC designer and architect, with a strong emphasis on high speed Nyquist A/D converters. For our purposes, the term 'high speed' is defined as sampling rates that are greater than 10 MS/s.

  19. Adjusting Your Gaze

    Science.gov (United States)

    Webber-Thrush, Diane

    2010-01-01

    Peter Wylie is a man of many contradictions: a statistician and a storyteller, an introvert who loves an audience, and a self-described data geek with a passion for his work and the people it helps. Wylie is one of the pioneers of predictive modeling, the statistical analysis that uses data to drive educational institutions and nonprofits toward…

  20. Control of Electric Drives in the Best Efficiency Region of Pumping System

    Directory of Open Access Journals (Sweden)

    Bakman Ilja

    2014-10-01

    Full Text Available The paper concentrates on improving the efficiency of the pumping system in which pumps are run by variable speed drives. The method is applicable to system consisting of several centrifugal pumps. Problems arising from running the pumps outside the optimal efficiency region are discussed. Common principles of operation and control of typical boosting pumping station are represented. Methods of regulation of productivity of the system are described. The proposed method is based on prediction of future efficiency of pumps before making adjustments of pumping system productivity. The proposed method is basing on tracking the working point of pump on efficiency graph. Monitoring the location of working point vs. efficiency graph enables to evaluate its current and future distances from the best efficiency point of the pump. Knowing the current number of running pumps it is possible to predict the location of working point after adjustment of productivity of the system. Ability to predict the increase or decrease of efficiency enables to enhance the adjustment of productivity of the system. Methods of graphical analysis of working state of the pumping system are representing topic for future research.

  1. Handling performance control for hybrid 8-wheel-drive vehicle and simulation verification

    Science.gov (United States)

    Ni, Jun; Hu, Jibin

    2016-08-01

    In order to improve handling performance of a hybrid 8-Wheel-Drive vehicle, the handling performance control strategy was proposed. For armoured vehicle, besides handling stability in high speed, the minimum steer radius in low speed is also a key tactical and technical index. Based on that, the proposed handling performance control strategy includes 'Handling Stability' and 'Radius Minimization' control modes. In 'Handling Stability' control mode, 'Neutralsteer Radio' is defined to adjust the steering characteristics to satisfy different demand in different speed range. In 'Radius Minimization' control mode, the independent motors are controlled to provide an additional yaw moment to decrease the minimum steer radius. In order to verify the strategy, a simulation platform was built including engine and continuously variable transmission systems, generator and battery systems, independent motors and controllers systems, vehicle dynamic and tyre mechanical systems. The simulation results show that the handling performance of the vehicle can be enhanced significantly, and the minimum steer radius can be decreased by 20% which is significant improvement compared to the common level of main battle armoured vehicle around the world.

  2. A High Revolution Speed Noncontact Ultrasonic Motor Driven by a Non-Symmetrical Electrode

    Institute of Scientific and Technical Information of China (English)

    YANG Bin; LIU Jing-Quan; CHEN Di; CAI Bing-Chu

    2005-01-01

    @@ A noncontact ultrasonic motor based on a non-symmetrical electrode is proposed. This motor has the advantages of using a simple driving electrode and having a high revolution speed. The revolution speed of its three-blade rotor can reach 5100rpm under a driving voltage of 20 V. A method operated easily is proposed to measure the output torque.

  3. Tennis playing is related to psychomotor speed in older drivers.

    Science.gov (United States)

    Marmeleira, José; Melo, Filipe; Tlemcani, Mouhaydine; Fernandes, Jorge

    2013-10-01

    The study investigated the association of tennis playing and running with the psychomotor speed of older drivers. Thirty-six active male drivers (M age = 63.2 yr.) participated. A battery of four on-the road driving tests was performed by tennis players, runners, and a control group. Measures of simple and choice reaction time, movement time, and response time were collected under single- and dual-task conditions. A composite driving score was calculated from reaction time measures of all driving tasks to reflect a general drivers' psychomotor speed. Statistically significant differences between groups were found in a braking task; tennis players performed significantly better than controls in simple reaction time and response time. The composite driving score also differed between groups, and tennis players had better results than controls. Regular participation in tennis was related to psychomotor speed of older drivers.

  4. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  5. Recognizing driving in haste

    NARCIS (Netherlands)

    Rendón-Vélez, E.

    2014-01-01

    One can often hear people discussing the reasons why a road accident has happened: “She had to pick up her kids in the school before four o’clock and she was driving in haste and careless”, “He was stressed, he wanted to reach the beginning of the football match, tried to drive faster and didn't app

  6. Drive Around the World

    Institute of Scientific and Technical Information of China (English)

    Yang Wei

    2008-01-01

    @@ "It's so cool that I can drive on my own,and my own car,"Cao Gang,WOrking for a private company in Changsha,capital city of Hunan Province,mid-south China,said in excitement when he newly bought Ben Ben,a Chinese local auto brand of Chang'an,with his freshly-passed driving license.

  7. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  8. Electric vehicles: Driving range

    Science.gov (United States)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  9. Fundamentals of electrical drives

    CERN Document Server

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  10. Simple Driving Techniques

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    2002-01-01

    Driving was introduced as a program transformation technique by Valentin Turchin in some papers around 1980. It was intended for the programming language REFAL and used in metasystem transitions based on super compilation. In this paper we present one version of driving for a more conventional li...

  11. Stator insulation systems for medium voltage PWM drives fed motors

    Energy Technology Data Exchange (ETDEWEB)

    Gao, G.; Chen, W. [TECO-Westinghouse Motor Co., Round Rock, TX (United States)

    2005-07-01

    Adjustable speed drives (ASD) are commonly used in power electronics and control systems. It is estimated that more than 15 per cent of medium voltage motors are currently fed by such drives worldwide. A research project was conducted to examine the influence of medium voltage pulse width modulated (PWM) ASD on motor stator insulation systems. The findings, based on accelerated laboratory tests, have helped designers to improve the capabilities of the insulation system used for ASD-fed motors. Repetitive, high magnitude voltage spikes with fast rise time create significant stress on insulation systems. Gradual deterioration and premature failure of the motor insulation can result from surge voltages which generate surface discharges between phase windings/end windings, or partial discharges between stator turns. However, there is no industrial standard to evaluate motor insulation life under ASD-cable-motor conditions. Several material manufacturers have developed their own version of corona resistant material. However, the insulation life of ASD-fed motors does not depend solely on the raw materials. Rather, it depends on the complete insulation system, including the stator manufacturing process. In order to address this problem, TECO-Westinghouse Motor Company has developed special design criteria and manufacturing practices in order to reduce winding insulation temperature and to compensate for the additional heat generated by high frequency contents in the PWM voltage waveform. A patent pending new cooling system should reduce winding temperature by 15 to 20 degrees C. This paper presented design considerations for turn insulation, groundwall insulation, and a voltage stress grading system. A new thermal class H insulation system was also described. 6 refs., 2 tabs., 5 figs.

  12. Torque- and Speed Control of a Pitch Regulated Wind Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Rasila, Mika

    2003-07-01

    Variable speed operated wind turbines has the potential to reduce fatigue loads, compared to fixed speed wind turbines. With pitch controllable rotor blades limitation of the power at high wind speeds is obtained. The thesis describes different controlling aspects concerning wind turbines and how these together can be used to optimize the system's performance. Torque control is used in order to achieve reduction on the mechanical loads on the drive-train for low wind speeds and limitation of power output for high wind speeds. In the high wind speed interval torque control is effective in order to limit the output power if a sufficiently fast pitch actuator is used. In the middle wind speed interval filter utilization can be used to give a reference signal to the controller in order to reduce speed and torque variations.

  13. Auto Adjusting Astronomical Telescope

    Directory of Open Access Journals (Sweden)

    Rohit R. Ghalsasi

    2014-04-01

    Full Text Available Astronomical telescope is powerful and basic tool for star or celestial observation. Here we proposed integrated system using Raspberry Pi for auto adjusting astronomical telescope. This integrated circuit helps to control stellar monitoring, stellar targeting, and tracking functions of telescope. Astro compass gives the direction of the celestial objects.

  14. Psychological Adjustment and Homosexuality.

    Science.gov (United States)

    Gonsiorek, John C.

    In this paper, the diverse literature bearing on the topic of homosexuality and psychological adjustment is critically reviewed and synthesized. The first chapter discusses the most crucial methodological issue in this area, the problem of sampling. The kinds of samples used to date are critically examined, and some suggestions for improved…

  15. Sustainable urban regime adjustments

    DEFF Research Database (Denmark)

    Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten;

    2013-01-01

    The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

  16. A Novel Motor-Speed-Regulation Method

    Directory of Open Access Journals (Sweden)

    Huang Zhou

    2016-01-01

    Full Text Available The traditional doubly-fed motor has less reliability because it needs carbon brushes and sliding rings which are not highly reliable. The brushless doubly-fed machine costs a lot for its framework requires special designing and processing. To overcome the disadvantages of the two kinds of motors, this paper focuses on a novel method of motor speed regulation which is based on rotating feeding. The motor speed changing around its rated speed can be realized based on the method without any carbon brush or sliding ring on the prosaic electrical motors. On the basis of the full controlled thyristor rectifying bridge structure, the basic idea is introduced; the advantages and disadvantages of this method are analyzed. This kind of systems can replace the brushed or brushless double-fed systems. They are very suitable for driving fans or pumps, or power-generating systems with variable speed constant frequency such as wind power or water power generating systems.

  17. Pitch Angle Control for Variable Speed Wind Turbines

    DEFF Research Database (Denmark)

    Chen, Zhe; Zhang, Jianzhong; Cheng, M;

    2008-01-01

    controller, the mathematical model of the system should be known well. A fuzzy logic pitch angle controller is developed in this paper, in which it does not need well known about the system and the mean wind speed is used to compensate the non-linear sensitivity. The fuzzy logic control strategy may have......Pitch angle control is the most common means for adjusting the aerodynamic torque of the wind turbine when wind speed is above rated speed and various controlling variables may be chosen, such as wind speed, generator speed and generator power. As conventional pitch control usually use PI...

  18. Efficiency optimized control of medium-size induction motor drives

    DEFF Research Database (Denmark)

    Abrahamsen, F.; Blaabjerg, Frede; Pedersen, John Kim;

    2000-01-01

    The efficiency of a variable speed induction motor drive can be optimized by adaption of the motor flux level to the load torque. In small drives (... not be disregarded without further analysis. The importance of the converter losses on efficiency optimization in medium-size drives is analyzed in this paper. Based on the experiments with a 90 kW drive it is found that it is not critical if the converter losses are neglected in the control, except...... that the robustness towards load disturbances may unnecessarily be reduced. Both displacement power factor and model-based efficiency optimizing control methods perform well in medium-size drives. The last strategy is also tested on a 22 kW drive with good results....

  19. Single-to-three phase induction motor sensorless drive system

    Directory of Open Access Journals (Sweden)

    Z.M.S. El-Barbary

    2012-06-01

    Full Text Available This paper presented a single to three-phase induction motor drive system to provide variable output voltage and frequency. The proposed drive system employs only six IGBT switches, which form the front-end rectifier and the output inverter for the one step conversion from single-phase supply to output three-phase supply. The front-end rectifier permits bidirectional power flow and provides excellent regulation against fluctuations in source voltage. Moreover, it incorporates active input current shaping feature. The control strategy of the proposed drive system of three-phase induction motor is based on speed sensorless vector control technique. A low cost of motor drive and much more advantages can be achieved using the proposed drive system. Simulation and experimental results are carried out to analysis and explore the characteristics of the proposed drive system.

  20. The Design of Sport Bicycle Speed Odometer

    Directory of Open Access Journals (Sweden)

    Dongbing Liu

    2013-04-01

    Full Text Available As bicycle sport equipment, a sport bike needs a speed and distance measuring device, due to the characteristic of road cycling, thereby mastering the state of motion. According to external conditions such as temperature, wind speed, the bike can make the appropriate adjustment to achieve the best movement effect. The bicycle speed odometer is a major accessibility tool that satisfies with needs of the people with fast development. This study elaborated a bike speed odometer design based on Hall element, taking AT89C52 single chip as the core, measuring speed with A44E Hall sensor, to finish the bike mileage/speed measurement and statistics by displaying bike mileage and speed in real time. By using the Hall elements, the hardware of speed odometer input the number of pulse of per circle into the single-chip computer system. Then the signal processed by the single-chip computer displays. The software is programmed with assembly language and modular design idea. The design of the hardware circuit is simple and the subroutine has universal property, which fully meet the design requirements and possess a wide range of application and dissemination value.

  1. A laboratory driving simulation for assessment of driving behavior in adults with ADHD: a controlled study

    Directory of Open Access Journals (Sweden)

    Aleardi Megan

    2007-01-01

    Full Text Available Abstract Background It is now estimated that attention deficit-hyperactivity disorder (ADHD afflicts at least 4% of adults in the United States and is associated with high levels of morbidity and functional impairment. One key area of dysfunction associated with ADHD is impaired motor vehicle operation. Our goal was to examine the association between ADHD and specific driving outcomes in a sample of adults using a driving simulator. Methods Subjects were 20 adults with full DSM-IV ADHD and 21 controls without ADHD of equal gender distribution. However, the mean age of subjects with ADHD was somewhat older. All analyses were adjusted for age and gender. All subjects participated in a driving simulation that lasted for one hour and consisted of a short training period, a high stimulus segment and a low stimulus segment with two distinct monotonous periods. Results In the second monotonous period within the low stimulus environment, ADHD subjects were significantly more likely than controls to collide with an obstacle suddenly appearing from the periphery, adjusting for age and gender. Conclusion Adults with ADHD were more likely than controls to collide with an obstacle during a driving simulation suggesting that deficits in directed attention may underlie driving impairments in this population.

  2. 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 esti......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...

  3. Polar Direct Drive

    Science.gov (United States)

    Skupsky, S.

    2003-10-01

    Direct drive offers the potential of higher target gain on the National Ignition Facility (NIF) than x-ray drive: The initial direct-drive target design had a 1-D gain of 45 and consisted primarily of a pure cryogenic DT shell. Using the expected levels of target and laser nonuniformities for the NIF, two-dimensional (2-D) hydrodynamic simulations predicted target gains around 30.(P.W. McKenty et al.), Phys. Plasmas 8, 2315 (2001). More-recent designs have shown that higher target gains could be obtained by replacing a portion of the DT shell with ``wetted'' CH foam and by using adiabat shaping: (1) Higher-Z material (C) in the foam increases laser absorption by about 40% (from 60% absorption to 85%).(S. Skupsky et al.), in Inertial Fusion Sciences and Applications 2001, edited by K. Tanaka et al. (Elsevier, Paris, 2002), p. 240. (2) Adiabat shaping allows the main portion of the fuel to be placed on a lower adiabat without compromising target stability.(V.N. Goncharov et al.), Phys. Plasmas 10, 1906 (2003). These direct-drive concepts can be tested on the NIF, long before that facility is converted to a direct-drive (spherically symmetric) irradiation configuration. Using the NIF x-ray-drive beam configuration, some of the near-polar beams could be pointed to better illuminate the target's equator. These more-oblique, equatorial beams will have lower absorption and reduced drive efficiency than the polar beams. One strategy to compensate for the difference in polar and equatorial drive is to reduce the irradiation at the poles and employ different pulse shapes to accommodate the time-dependent variations in drive and absorption. This concept of polar direct drive (PDD) has been studied using the 2-D hydrocode DRACO to determine the requirements for achieving ignition and moderate target gain for the NIF. Experiments on the OMEGA laser will examine the effects of oblique irradiation on target drive. Results of simulations for different direct-drive target designs

  4. Control of Adjustable Compliant Actuators

    Directory of Open Access Journals (Sweden)

    Berno J.E. Misgeld

    2014-05-01

    Full Text Available Adjustable compliance or variable stiffness actuators comprise an additional element to elastically decouple the actuator from the load and are increasingly applied to human-centered robotic systems. The advantages of such actuators are of paramount importance in rehabilitation robotics, where requirements demand safe interaction between the therapy system and the patient. Compliant actuator systems enable the minimization of large contact forces arising, for example, from muscular spasticity and have the ability to periodically store and release energy in cyclic movements. In order to overcome the loss of bandwidth introduced by the elastic element and to guarantee a higher range in force/torque generation, new actuator designs consider variable or nonlinear stiffness elements, respectively. These components cannot only be adapted to the walking speed or the patient condition, but also entail additional challenges for feedback control. This paper introduces a novel design method for an impedance-based controller that fulfills the control objectives and compares the performance and robustness to a classical cascaded control approach. The new procedure is developed using a non-standard positive-real Η2 controller design and is applied to a loop-shaping approach. Robust norm optimal controllers are designed with regard to the passivity of the actuator load-impedance transfer function and the servo control problem. Classical cascaded and positive-real Η2 controller designs are validated and compared in simulations and in a test bench using a passive elastic element of varying stiffness.

  5. Metric adjusted skew information

    DEFF Research Database (Denmark)

    Hansen, Frank

    2008-01-01

    establish a connection between the geometrical formulation of quantum statistics as proposed by Chentsov and Morozova and measures of quantum information as introduced by Wigner and Yanase and extended in this article. We show that the set of normalized Morozova-Chentsov functions describing the possible...... quantum statistics is a Bauer simplex and determine its extreme points. We determine a particularly simple skew information, the "¿-skew information," parametrized by a ¿ ¿ (0, 1], and show that the convex cone this family generates coincides with the set of all metric adjusted skew informations.......We extend the concept of Wigner-Yanase-Dyson skew information to something we call "metric adjusted skew information" (of a state with respect to a conserved observable). This "skew information" is intended to be a non-negative quantity bounded by the variance (of an observable in a state...

  6. Fiscal adjustment in Brazil

    Directory of Open Access Journals (Sweden)

    Fabiana Rocha

    2003-03-01

    Full Text Available Two questions are addressed in this paper. The first one is the determination of periods of fiscal consolidation and fiscal stimulus. The second one is the importance of the composition of fiscal adjustments for their success, defined as a declining debt to GDP ratio. We, characterize 1994 and 1999 as points of fiscal consolidation. The 1994 consolidation can not be considered successful since after that period the debt to GDP ratio has grown continuously. The adjustment can be characterized as a type 2 adjustment (Alesina and Perotti (1997 in the sense that cuts were made mainly in public investment, while government wages and transfers remained almost unchanged. This type of adjustment usually has a low likelihood of being a success.Duas questões são tratadas neste artigo. A primeira é a determinação dos períodos de consolidação fiscal e estímulo fiscal. A segunda questão é a importância da composição dos ajustamentos fiscais para o seu sucesso, definido como um declínio na razo dívida/PIB. Nós, caracterizamos 1994 e 1999 como pontos de consolidação fiscal. A consolidação de 1994 não pode ser considerada um sucesso pois nos anos seguintes a razão dívida/PIB cresceu continuamente. O ajustamento pode ser considerado como um ajustamento do tipo 2 (Alesina and Perotti, 1997 no sentido de que foram feitos cortes principalmente no investimento público, enquanto os salários e transferências permaneceram praticamente inalterados. Este tipo de ajustamento geralmente tem uma baixa probabilidade de sucesso.

  7. Development of a KT driving cycle for UMT PHEV powertrain

    Science.gov (United States)

    Atiq, W. H.; Haezah, M. N.; Norbakyah, J. S.; Salisa, A. R.

    2015-12-01

    Driving cycles were identified as one of the core sources that contribute to develop the powertrain for vehicle. Plug-in hybrid electric vehicles (PHEVs) are the future transport for next generation. Compared to conventional internal combustion engine vehicle, hybrid and electric vehicle can improve fuel economy and reduce green house gases. This paper describes a development of Kuala Terengganu driving cycle for Universiti Malaysia Terengganu PHEV. Car speed-time data along the two selected fixed route is obtained by using on-board technique which is Global Positioning System, GPS. The developed driving cycle contains a 1050s speed time series, with a distance of 2.17 km, and an average and a maximum speed of 20.67 km/h and 61.47 km/h, respectively. The results obtained from this analysis are within reasonable range and satisfactory.

  8. Neural network based PWM AC chopper fed induction motor drive

    Directory of Open Access Journals (Sweden)

    Venkatesan Jamuna

    2009-01-01

    Full Text Available In this paper, a new Simulink model for a neural network controlled PWM AC chopper fed single phase induction motor is proposed. Closed loop speed control is achieved using a neural network controller. To maintain a constant fluid flow with a variation in pressure head, drives like fan and pump are operated with closed loop speed control. The need to improve the quality and reliability of the drive circuit has increased because of the growing demand for improving the performance of motor drives. With the increased availability of MOSFET's and IGBT's, PWM converters can be used efficiently in low and medium power applications. From the simulation studies, it is seen that the PWM AC chopper has a better harmonic spectrum and lesser copper loss than the Phase controlled AC chopper. It is observed that the drive system with the proposed model produces better dynamic performance, reduced overshoot and fast transient response. .

  9. Indirect sensorless speed control of a PMSG for wind application

    DEFF Research Database (Denmark)

    Diaz, S.A.; Silva, C.; Juliet, J.

    2009-01-01

    the method usually referred in the literature as indirect speed control (ISC). The principle of this method is the regulation of the generator torque as function of rotor speed such that the steady state operation is at the MPPT. This strategy normally requires the knowledge of the shaft speed to determinate...... in the whole wind generator system a sensorless scheme is proposed, thereby avoiding problems of electromagnetic interferences and failures in the position sensor. Usually, in wind drive system, the generator is not operated a very low speeds, therefore problems related to low back-emf for flux estimation...... by a squirrel cage induction machine used as wind turbine emulator and the permanent magnet generator. A control program uses a simulated wind profile and gives the speed reference for the induction machine drive, considering the turbine torque production and the inertia of the system. Experimental results...

  10. Assessment: A Driving Force.

    Science.gov (United States)

    Rakow, Steven J.

    1992-01-01

    Asserts that educational assessment drives the curriculum. Thus, assessment is very important in contemplating reform in science education. Assessment should be an integral part of the instructional process, utilizing diagnostic testing, monitoring, and summative evaluations. (PR)

  11. Driving in a womb

    NARCIS (Netherlands)

    Anonymous

    Drive thousands of kilometres on just a litre of fuel? During the annual Shell eco-marathon at the end of May, schoolchildren and students – including a team from TU Delft – demonstrated that it can indeed be done.

  12. Space Drive Physics: Introduction and Next Steps

    Science.gov (United States)

    Millis, M. G.

    Research toward the visionary goal of propellantless ``space drives'' is introduced, covering key physics issues and a listing of roughly 2-dozen approaches. The targeted advantage of a space drive is to circumvent the propellant constraints of rockets and the maneuvering limits of light sails by using the interactions between the spacecraft and its surrounding space for propulsion. At present, the scientific foundations from which to engineer a space drive have not been discovered and, objectively, might be impossible. Although no propulsion breakthroughs appear imminent, the subject has matured to where the relevant questions have been broached and are beginning to be answered. The critical make-break issues include; conservation of momentum, uncertain sources of reaction mass, and the net-external thrusting requirement. Note: space drives are not necessarily faster- than-light devices. Speed limits are a separate, unanswered issue. Relevant unsolved physics includes; the sources and mechanisms of inertial frames, coupling of gravitation and electromagnetism, and the nature of the quantum vacuum. The propulsion approaches span mostly stages 1 through 3 of the scientific method (defining the problem, collecting data, and articulating hypotheses), while some have matured to stage 4 (testing hypotheses). Nonviable approaches include `stiction drives,' `gyroscopic antigravity,' and `lifters.' No attempt is made to gauge the prospects of the remaining approaches. Instead, a list of next-step research questions is derived from the examination of these goals, unknowns, and concepts.

  13. Speed Control of Induction Motor by Using Variable Frequency

    Directory of Open Access Journals (Sweden)

    Drive Pooja Shinde

    2014-04-01

    Full Text Available The variable speed drive is focused on voltage amplitude control. However, its only control speed in constraint limits. The load on Induction Motor is not constant & vary as per load requirement. so speed must be change as per load. If the supply voltage decreased motor torque also decreases, for maintaining same torque, slip decreases hence speed falls and motor speed is directly proportional to supply frequency, hence to maintain a speed, the supply V/F ratio must be vary accordingly. But the speed is not vary proportion to application so it consume the rated power and it becomes economically disadvantages. To overcome above problem a new concept of Variable Frequency Drive (VFD is introduced. Adding a Variable Frequency Drive (VFD to a motor driven system can offer potential energy saving in a system in which the load vary with time. The primary function of VFD in application is to provide energy saving, speed reduction of 20% can save energy upto 50%.

  14. Instant Google Drive starter

    CERN Document Server

    Procopio, Mike

    2013-01-01

    This book is a Starter which teaches you how to use Google Drive practically. This book is perfect for people of all skill levels who want to enjoy the benefits of using Google Drive to safely store their files online and in the cloud. It's also great for anyone looking to learn more about cloud computing in general. Readers are expected to have an Internet connection and basic knowledge of using the internet.

  15. Adjustment Criterion and Algorithm in Adjustment Model with Uncertain

    Directory of Open Access Journals (Sweden)

    SONG Yingchun

    2015-02-01

    Full Text Available Uncertainty often exists in the process of obtaining measurement data, which affects the reliability of parameter estimation. This paper establishes a new adjustment model in which uncertainty is incorporated into the function model as a parameter. A new adjustment criterion and its iterative algorithm are given based on uncertainty propagation law in the residual error, in which the maximum possible uncertainty is minimized. This paper also analyzes, with examples, the different adjustment criteria and features of optimal solutions about the least-squares adjustment, the uncertainty adjustment and total least-squares adjustment. Existing error theory is extended with new observational data processing method about uncertainty.

  16. Self-driving carsickness.

    Science.gov (United States)

    Diels, Cyriel; Bos, Jelte E

    2016-03-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and productivity. However, we here show that the envisaged scenarios all lead to an increased risk of motion sickness. As such, the benefits this technology is assumed to bring may not be capitalised on, in particular by those already susceptible to motion sickness. This can negatively affect user acceptance and uptake and, in turn, limit the potential socioeconomic benefits that this emerging technology may provide. Following a discussion on the causes of motion sickness in the context of self-driving cars, we present guidelines to steer the design and development of automated vehicle technologies. The aim is to limit or avoid the impact of motion sickness and ultimately promote the uptake of self-driving cars. Attention is also given to less well known consequences of motion sickness, in particular negative aftereffects such as postural instability, and detrimental effects on task performance and how this may impact the use and design of self-driving cars. We conclude that basic perceptual mechanisms need to be considered in the design process whereby self-driving cars cannot simply be thought of as living rooms, offices, or entertainment venues on wheels.

  17. Dementia and driving.

    Science.gov (United States)

    O'Neill, D; Neubauer, K; Boyle, M; Gerrard, J; Surmon, D; Wilcock, G K

    1992-04-01

    Many European countries test cars, but not their drivers, as they age. There is evidence to suggest that human factors are more important than vehicular factors as causes of motor crashes. The elderly also are involved in more accidents per distance travelled than middle-aged drivers. As the UK relies on self-certification of health by drivers over the age of 70 years, we examined the driving practices of patients with dementia attending a Memory Clinic. Nearly one-fifth of 329 patients with documented dementia continued to drive after the onset of dementia, and impaired driving ability was noted in two-thirds of these. Their families experienced great difficulty in persuading patients to stop driving, and had to invoke outside help in many cases. Neuropsychological tests did not help to identify those who drove badly while activity of daily living scores were related to driving ability. These findings suggest that many patients with dementia drive in an unsafe fashion after the onset of the illness. The present system of self-certification of health by the elderly for driver-licensing purposes needs to be reassessed.

  18. Modal analysis of coupled vibration of belt drive systems

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-jun; CHEN Li-qun

    2008-01-01

    The modal method is applied to analyze coupled vibration of belt drive systems. A belt drive system is a hybrid system consisting of continuous belts modeled as strings as well as discrete pulleys and a tensioner arm. The characteristic equation of the system is derived from the governing equation. Numerical results demenstrate the effects of the transport speed and the initial tension on natural frequencies.

  19. Low Speed Automation, a French Initiative

    OpenAIRE

    Glaser, Sébastien; Cour, Maurice; NOUVELIERE, Lydie; LAMBERT, Alain; Nashashibi, Fawzi; Popieul, Jean-Christophe; Mourllion, Benjamin

    2012-01-01

    International audience; Nowadays, vehicle safety is constantly increasing thanks to the improvement of vehicle passive and active safety. However, on a daily usage of the car, traffic jams remains a problem. With limited space for road infrastructure, automation of the driving task on specific situation seems to be a possible solution. The French project ABV, which stands for low speed automation, tries to demonstrate the feasibility of the concept and to prove the benefits. In this article, ...

  20. SYSTEMS FOR THE ADJUSTMENT OF THE MAIN KINEMATIC CHAIN OF THE VERTICAL TURNING LATHES

    Directory of Open Access Journals (Sweden)

    Dan PRODAN

    2011-07-01

    Full Text Available This paperwork presents some systems for the adjustment of the main kinematic chains of theVertical Turning Lathes that have been used within the last 20 years. There are presented adjustment systemsused when having the machine equipped with older type motors, with only one speed, and also modern systemsfor which A.C. motors with the speed adjustable by frequency variation are needed. It insists on the presentrole of the “gearboxes” as torque multipliers and not as speed reducer.

  1. On the impossibility of superluminal travel: the warp drive lesson

    CERN Document Server

    Barceló, Carlos; Liberati, Stefano

    2010-01-01

    The question of whether it is possible or not to surpass the speed of light is already centennial. The special theory of relativity took the existence of a speed limit as a principle, the light postulate, which has proven to be enormously predictive. Here we discuss some of its twists and turns when general relativity and quantum mechanics come into play. In particular, we discuss one of the most interesting proposals for faster than light travel: warp drives. Even if one succeeded in creating such spacetime structures, it would be still necessary to check whether they would survive to the switching on of quantum matter effects. Here, we show that the quantum back-reaction to warp-drive geometries, created out of an initially flat spacetime, inevitably lead to their destabilization whenever superluminal speeds are attained. We close this investigation speculating the possible significance of this further success of the speed of light postulate.

  2. The Relationship between Road Design and Driving Behavior

    DEFF Research Database (Denmark)

    Abele, Liva; Møller, Mette

    2011-01-01

    . Improving road infrastructure safety can be achieved by making roads forgiving and self-explaining. This could be done by clarifying the road design characteristics for each road category. The effect on driver behavior by varying road-shoulders and presence of roadside trees was tested by means of a fixed...... experiments using larger sample sizes to visualize the impact of different road designs on the driving behavior prior to costly deployment. However, the results are highly relevant for the understanding of the influence of road design features on driver behavior as well as for the understanding of the use......Speed is a substantial factor contributing to road safety. Currently, speed reduction is mainly achieved through law enforcement and the implementation of traffic calming measures. An alternative speed reducing approach is to encourage drivers to voluntarily choose an appropriate driving speed...

  3. The impact of integrated full-range speed assistance on traffic flow

    NARCIS (Netherlands)

    Wilmink, I.; Klunder, G.; Arem, B. van

    2006-01-01

    This paper discusses the assessment of the effects of Integrated full-Range Speed Assistance (IRSA), using the ITS modeller. The aim of IRSA is to assist drivers in their longitudinal driving task by providing speed advice or speed warnings and cruise control-like functionalities. The effects of the

  4. Traffic flow effects of Integrated full-range Speed Assistance (IRSA)

    NARCIS (Netherlands)

    Wilmink, I.R.; Klunder, G.; Arem, B. van

    2007-01-01

    This paper discusses the assessment of the effects of Integrated full-Range Speed Assistance (IRSA), using the ITS modeller. The aim of IRSA is to assist drivers in their longitudinal driving task by providing speed advice or speed warnings and cruise control-like functionalities. The effects of the

  5. Jordan Adjusted Human Development

    OpenAIRE

    Ababsa, Myriam

    2014-01-01

    Jordan Human Development Index (HDI) and Adjusted Human Development Index (IHDI) In 1990, the United Nations Development Programme designed a Human Development Index composed of life expectancy at birth, level of education and gross domestic product (GDP) per capita. In 2011, the UNDP ranked Jordan 95th out of 187 countries with a human development index of 0.698, up from 0.591 in 1990, making it the leading medium-range country for human development (fig. VIII.1). In 2010, the inequality adj...

  6. Adjustable Reeds For Weaving

    Science.gov (United States)

    Farley, Gary L.

    1994-01-01

    Local characteristics of fabrics varied to suit special applications. Adjustable reed machinery proposed for use in weaving fabrics in various net shapes, widths, yarn spacings, and yarn angles. Locations of edges of fabric and configuration of warp and filling yarns varied along fabric to obtain specified properties. In machinery, reed wires mounted in groups on sliders, mounted on lengthwise rails in reed frame. Mechanisms incorporated to move sliders lengthwise, parallel to warp yarns, by sliding them along rails; move sliders crosswise by translating reed frame rails perpendicular to warp yarns; and crosswise by spreading reed rails within group. Profile of reed wires in group on each slider changed.

  7. An IFOC-DSVPWM Based DC-Link Voltage Compensation of Z-Source Inverter Fed Induction Motor Drive for EVs

    Directory of Open Access Journals (Sweden)

    Ananda Kumar Akkarapaka

    2015-01-01

    Full Text Available The drop in DC-link voltage of adjustable speed drives (ASD occurs mainly due to the increase in output power demands. This may lead to inefficient operation and eventually the tripping of the drive. This paper presents a Double Space Vector Pulse Width Modulation (DSVPWM technique for boosting and compensating the DC-link voltage of Z-source inverter (ZSI. The DSVPWM technique estimates the required shoot through period of the Z-source inverter to maintain the DC-link voltage constant at the desired level through capacitor voltage control. The DSVPWM can obtain maximum boost at any given modulation index in comparison to simple boost control (SBC method. It also utilizes the dead time more effectively. The speed control of the ZSI fed induction motor drive is done by employing indirect field-oriented (IFO control method. A 32-bit DSP (TMS320F28335 is used to implement the IFOC-DSVPWM method for ZSI. The power structure and the modulation technique are well suited for electric vehicle application.

  8. Continuously adjustable Pulfrich spectacles

    Science.gov (United States)

    Jacobs, Ken; Karpf, Ron

    2011-03-01

    A number of Pulfrich 3-D movies and TV shows have been produced, but the standard implementation has inherent drawbacks. The movie and TV industries have correctly concluded that the standard Pulfrich 3-D implementation is not a useful 3-D technique. Continuously Adjustable Pulfrich Spectacles (CAPS) is a new implementation of the Pulfrich effect that allows any scene containing movement in a standard 2-D movie, which are most scenes, to be optionally viewed in 3-D using inexpensive viewing specs. Recent scientific results in the fields of human perception, optoelectronics, video compression and video format conversion are translated into a new implementation of Pulfrich 3- D. CAPS uses these results to continuously adjust to the movie so that the viewing spectacles always conform to the optical density that optimizes the Pulfrich stereoscopic illusion. CAPS instantly provides 3-D immersion to any moving scene in any 2-D movie. Without the glasses, the movie will appear as a normal 2-D image. CAPS work on any viewing device, and with any distribution medium. CAPS is appropriate for viewing Internet streamed movies in 3-D.

  9. Driving anger in Malaysia.

    Science.gov (United States)

    Sullman, Mark J M; Stephens, Amanda N; Yong, Michelle

    2014-10-01

    The present study examined the types of situations that cause Malaysian drivers to become angry. The 33-item version of the driver anger scale (Deffenbacher et al., 1994) was used to investigate driver anger amongst a sample of 339 drivers. Confirmatory factor analysis showed that the fit of the original six-factor model (discourtesy, traffic obstructions, hostile gestures, slow driving, illegal driving and police presence), after removing one item and allowing three error pairs to covary, was satisfactory. Female drivers reported more anger, than males, caused by traffic obstruction and hostile gestures. Age was also negatively related to five (discourtesy, traffic obstructions, hostile gestures, slow driving and police presence) of the six factors and also to the total DAS score. Furthermore, although they were not directly related to crash involvement, several of the six forms of driving anger were significantly related to the crash-related conditions of: near misses, loss of concentration, having lost control of a vehicle and being ticketed. Overall the pattern of findings made in the present research were broadly similar to those from Western countries, indicating that the DAS is a valid measure of driving anger even among non-European based cultures.

  10. Base drive circuit for a four-terminal power Darlington

    Science.gov (United States)

    Lee, Fred C.; Carter, Roy A.

    1983-01-01

    A high power switching circuit which utilizes a four-terminal Darlington transistor block to improve switching speed, particularly in rapid turn-off. Two independent reverse drive currents are utilized during turn off in order to expel the minority carriers of the Darlington pair at their own charge sweep-out rate. The reverse drive current may be provided by a current transformer, the secondary of which is tapped to the base terminal of the power stage of the Darlington block. In one application, the switching circuit is used in each power switching element in a chopper-inverter drive of an electric vehicle propulsion system.

  11. Feed Drive Based upon Linear Motor for Ultraprecision Turning Machine

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The characteristics of several different linear motors have been investigated, and the feed drive system with linear motor instead of screw-nut mechanism has been built for a submicro ultraprecision turning machine. In the control system for the feed drive system arranged as "T", both P-position and PI-speed control loops are used. The feedback variable is obtained from a double frequecy laser interferometor. Experiments show that the feed drive with linear motor is simple in construction, and that its dynamics is better than others. So the machining accuracy of the workpiece machined has been successfully improved.

  12. Development of Urban Driving Cycle with GPS Data Post Processing

    Directory of Open Access Journals (Sweden)

    Peter Lipar

    2016-08-01

    Full Text Available This paper presents GIS-based methodology for urban area driving cycle construction. The approach reaches beyond the frames of usual driving cycle development methods and takes into account another perspective of data collection. Rather than planning data collection, the approach is based on available in-vehicle measurement data post processing using Geographic Information Systems to manipulate the excessive database and extract only the representative and geographically limited individual trip data. With such data post processing the data was carefully adjusted to include only the data that describe representative driving in Ljubljana urban area. The selected method for the driving cycle development is based on searching for the best microtrips combination while minimizing the difference between two vectors; one based on generated cycle and the other on the database. Accounting for a large random sample of actual trip data, our approach enables more representative area-specific driving cycle development than the previously used techniques.

  13. LOAD DISTRIBUTION ON DRUMS OF DOUBLE DRIVE BELT CONVEYOR

    Institute of Scientific and Technical Information of China (English)

    薛河; 苏清祖; 马胜利

    1999-01-01

    The double drum drive is widely used on the mine belt conveyor, which are divided the rigid connected double drums and separately driving double drums according to connected method of two drums. Because of the change of real work condition, the load distribution is changed on the two drive drums, which may produce a slippage between a drum and belt. Slippage may intensify the wear of the drum, and sometimes causing the fire of the belt. This restricts the development toward narrow belt, high velocity and large power of belt conveyor. In this paper, the factors affecting the load distribution of two drums of double drum belt conveyor are'systematically analyzed and some computing formulas derived, by these formulas, the actual load distribution onthe two drums of rigid connected or separately driving belt conveyor can be separately calculated. These formulas also can be as the theory base for adjusting the driving force of two drums.

  14. Prevalence of texting while driving and other risky driving behaviors among young people in Ontario, Canada: Evidence from 2012 and 2014.

    Science.gov (United States)

    Tucker, Sean; Pek, Simon; Morrish, Jayne; Ruf, Megan

    2015-11-01

    This paper reports on the prevalence of texting while driving and other risky driving behaviors by age and gender in two large samples of youth aged 16-19 years in Ontario, Canada. In Study 1 (N=6133), we found that males reported more frequent texting while driving and speeding than females and, in terms of age, sixteen year olds reported frequent texting while driving than older participants. In Study 2 (N=4450), which was conducted two years later, males again reported more frequent texting while driving, however there was no difference in the rate of talking on the phone while driving among males and females. Participants also reported on experiences that led to a significant reduction in their texting while driving. The most common reasons were the perceived danger of texting while driving, laws and fines against texting while driving, and observing close-calls and accidents experienced by other people. The results of both studies suggest that driving-related risk-taking behaviors co-occur and that young passengers in vehicles, including 14 and 15 year olds, are bystanders to texting while driving. Finally, there was a substantial decline in the prevalence of texting while driving across the studies. In Study 1, 27% of participants reported "sometimes" to "almost always" texting while driving compared to 6% of participants in Study 2. Limitations and implications for public campaigns targeted youth distracted driving are discussed.

  15. College students' prevalence and perceptions of text messaging while driving.

    Science.gov (United States)

    Harrison, Marissa A

    2011-07-01

    By analyzing self-reports from sample of 91 college students from the United States who are frequent drivers, the present study examined the prevalence of text messaging (or "texting") while driving and the incidence of recklessness and consequences that accompany this behavior. Analyses revealed that 91% of participants reported having used text messaging while driving, with many reporting doing so with passengers, including children, riding in their vehicles. Further, a substantial number of participants reported driving dangerously above the speed limit and drifting into other traffic lanes while texting, and many reported "sexting" and arguing via text messages while driving. However, these young drivers agreed that texting while driving is dangerous and should be illegal. These results and the limitations to the present study are discussed.

  16. Do in-car devices affect experienced users' driving performance?

    Directory of Open Access Journals (Sweden)

    Allert S. Knapper

    2015-07-01

    Full Text Available Distracted driving is considered to be an important factor in road safety. To investigate how experienced user's driving behaviour is affected by in-vehicle technology, a fixed-base driving simulator was used. 20 participants drove twice in a rich simulated traffic environment while performing secondary, i.e. mobile phone and navigation system tasks. The results show that mean speed was lower in all experimental conditions, compared to baseline driving, while subjective effort increased. Lateral performance deteriorated only during visual–manual tasks, i.e. texting and destination entry, in which the participants glanced off the forward road for a substantial amount of time. Being experienced in manipulating in-car devices does not solve the problem of dual tasking when the primary task is a complex task like driving a moving vehicle. The results and discussion may shed some light on the current debate regarding phone use hazards.

  17. U.S. DRIVE

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-03-16

    U.S. DRIVE, which stands for United States Driving Research and Innovation for Vehicle efficiency and Energy sustainability, is an expanded government-industry partnership among the U.S. Department of Energy; USCAR, representing Chrysler Group LLC, Ford Motor Company and General Motors; Tesla Motors; five energy companies – BP America, Chevron Corporation, ConocoPhillips, ExxonMobil Corporation, and Shell Oil Products US; two utilities – Southern California Edison and Michigan-based DTE Energy; and the Electric Power Research Institute (EPRI). The U.S. DRIVE mission is to accelerate the development of pre-competitive and innovative technologies to enable a full range of affordable and clean advanced light-duty vehicles, as well as related energy infrastructure.

  18. Fuzzy Logic Based Speed Control System for ThreePhase Induction Motor

    Directory of Open Access Journals (Sweden)

    Marwan A. Badran

    2013-05-01

    Full Text Available Three-phase induction motors have been used in a wide range of industry applications. Using modern technology, the speed of induction motor can be easily controlled by variable frequency drives (VFDs. These drives use high speed power transistors with various switching techniques, mainly PWM schemes. For several decades, conventional control systems were applied to electric drives to control the speed of induction motor. Although conventional controllers showed good results, but they still need tuning to obtain optimum results. The recent proposed control systems use fuzzy logic controller (FLC to enhance the performance of induction motor drives. In this paper, a fuzzy logic based speed control system is presented. The proposed controller has been designed with MATLAB/SIMULINK software, and it was tested for various operating conditions including load disturbance and sudden change of reference speed. The results showed better performance of the proposed controller compared with the conventional PI controller.

  19. Effect Of Vibration On Occupant Driving Performances Measured By Simulated Driving

    Directory of Open Access Journals (Sweden)

    Amzar Azizan

    2015-08-01

    Full Text Available Although the performance of vehicle driver has been well investigated in many types of environments however drowsy driving caused by vibration has received far less attention. Experiment procedures comprised of two 10-minutes simulated driving sessions in no-vibration condition and with-vibration condition. In with-vibration condition volunteers were exposed to a Gaussian random vibration with 1-15 Hz frequency bandwidth at 0.2 ms-2 r.m.s. for 30-minutes. A deviation in lane position and vehicle speed were recorded and analyzed. Volunteers have also rated their subjective drowsiness by giving score using Karolinska Sleepiness Scale KSS every 5-minutes interval. Strong evidence of driving impairment following 30-minutes exposure to vibration were found significant in all volunteers p 0.05.

  20. Adolescent Mothers' Adjustment to Parenting.

    Science.gov (United States)

    Samuels, Valerie Jarvis; And Others

    1994-01-01

    Examined adolescent mothers' adjustment to parenting, self-esteem, social support, and perceptions of baby. Subjects (n=52) responded to questionnaires at two time periods approximately six months apart. Mothers with higher self-esteem at Time 1 had better adjustment at Time 2. Adjustment was predicted by Time 2 variables; contact with baby's…

  1. Sensorless optimal sinusoidal brushless direct current for hard disk drives

    Science.gov (United States)

    Soh, C. S.; Bi, C.

    2009-04-01

    Initiated by the availability of digital signal processors and emergence of new applications, market demands for permanent magnet synchronous motors have been surging. As its back-emf is sinusoidal, the drive current should also be sinusoidal for reducing the torque ripple. However, in applications like hard disk drives, brushless direct current (BLDC) drive is adopted instead of sinusoidal drive for simplification. The adoption, however, comes at the expense of increased harmonics, losses, torque pulsations, and acoustics. In this paper, we propose a sensorless optimal sinusoidal BLDC drive. First and foremost, the derivation for an optimal sinusoidal drive is presented, and a power angle control scheme is proposed to achieve an optimal sinusoidal BLDC. The scheme maintains linear relationship between the motor speed and drive voltage. In an attempt to execute the sensorless drive, an innovative power angle measurement scheme is devised, which takes advantage of the freewheeling diodes and measures the power angle through the detection of diode voltage drops. The objectives as laid out will be presented and discussed in this paper, supported by derivations, simulations, and experimental results. The proposed scheme is straightforward, brings about the benefits of sensorless sinusoidal drive, negates the need for current sensors by utilizing the freewheeling diodes, and does not incur additional cost.

  2. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  3. Pulsation driving and convection

    Science.gov (United States)

    Antoci, Victoria

    2015-08-01

    Convection in stellar envelopes affects not only the stellar structure, but has a strong impact on different astrophysical processes, such as dynamo-generated magnetic fields, stellar activity and transport of angular momentum. Solar and stellar observations from ground and space have shown that the turbulent convective motion can also drive global oscillations in many type of stars, allowing to study stellar interiors at different evolutionary stages. In this talk I will concentrate on the influence of convection on the driving of stochastic and coherent pulsations across the Hertzsprung-Russell diagram and give an overview of recent studies.

  4. Toyota hybrid synergy drive

    Energy Technology Data Exchange (ETDEWEB)

    Gautschi, H.

    2008-07-01

    This presentation made at the Swiss 2008 research conference on traffic by Hannes Gautschi, director of service and training at the Toyota company in Switzerland, takes a look at Toyota's hybrid drive vehicles. The construction of the vehicles and their combined combustion engines and electric generators and drives is presented and the combined operation of these components is described. Braking and energy recovery are discussed. Figures on the performance, fuel consumption and CO{sub 2} output of the hybrid vehicles are compared with those of conventional vehicles.

  5. Speed and income

    DEFF Research Database (Denmark)

    Fosgerau, Mogens

    2005-01-01

    The relationship between speed and income is established in a microeconomic model focusing on the trade-off between travel time and the risk of receiving a penalty for exceeding the speed limit. This is used to determine when a rational driver will choose to exceed the speed limit. The relationship...... between speed and income is found again in the empirical analysis of a cross-sectional dataset comprising 60,000 observations of car trips. This is used to perform regressions of speed on income, distance travelled, and a number of controls. The results are clearly statistically significant and indicate...... an average income elasticity of speed of 0.02; it is smaller at short distances and about twice as large at the longest distance investigated of 200 km....

  6. ASPECTS OF DESIGN PROCESS AND CAD MODELLING OF AN ADJUSTABLE CENTRIFUGAL COUPLING

    Directory of Open Access Journals (Sweden)

    Adrian BUDALĂ

    2015-05-01

    Full Text Available The paper deals with constructive and functional elements of an adjustable coupling with friction shoes and adjustable driving. Also, the paper shows few stages of the design process, some advantages of the using CAD software and some comparative results prototype vs. CAD model.

  7. Dangers of Texting While Driving

    Science.gov (United States)

    ... nhtsa.gov/risky-driving/distracted-driving . Print Out Texting While Driving Guide (pdf) File a Complaint with the FCC ... Office: Consumer and Governmental Affairs Tags: Consumers - Distracted Driving - Health and Safety - Texting Federal Communications Commission 445 12th Street SW, Washington, ...

  8. Adjusting to the Emergent

    DEFF Research Database (Denmark)

    Revsbæk, Line

    In her doctoral thesis Line Revsbaek explores newcomer innovation related to organizational entry processes in a changing organization. She introduces process philosophy and complexity theory to research on organizational socialization and newcomer innovation. The study challenges assumptions...... in standardized induction programs where newcomers are cast in roles as insecure novices needing to be “taught the ropes” of the organizational culture. Linked with this, it is suggested that the prevailing dichotomy of ‘newcomer assimilation’ versus ‘organizational accommodation’ is replaced with a notion...... of ‘adjusting to the emergent’. Newcomer innovation is portrayed as carrying a variety of possible significations, such as unintentional innovation effects of newcomer’s proactive self-socializing behavior; an inspirational basis for designing innovation-generating employee induction; ‘resonant instances...

  9. 46 CFR 154.1864 - Vessel speed within speed reduction.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vessel speed within speed reduction. 154.1864 Section... Vessel speed within speed reduction. The master shall ensure that the speed of the vessel is not greater than the posted speed reduction....

  10. Circuit for Driving Piezoelectric Transducers

    Science.gov (United States)

    Randall, David P.; Chapsky, Jacob

    2009-01-01

    The figure schematically depicts an oscillator circuit for driving a piezoelectric transducer to excite vibrations in a mechanical structure. The circuit was designed and built to satisfy application-specific requirements to drive a selected one of 16 such transducers at a regulated amplitude and frequency chosen to optimize the amount of work performed by the transducer and to compensate for both (1) temporal variations of the resonance frequency and damping time of each transducer and (2) initially unknown differences among the resonance frequencies and damping times of different transducers. In other words, the circuit is designed to adjust itself to optimize the performance of whichever transducer is selected at any given time. The basic design concept may be adaptable to other applications that involve the use of piezoelectric transducers in ultrasonic cleaners and other apparatuses in which high-frequency mechanical drives are utilized. This circuit includes three resistor-capacitor networks that, together with the selected piezoelectric transducer, constitute a band-pass filter having a peak response at a frequency of about 2 kHz, which is approximately the resonance frequency of the piezoelectric transducers. Gain for generating oscillations is provided by a power hybrid operational amplifier (U1). A junction field-effect transistor (Q1) in combination with a resistor (R4) is used as a voltage-variable resistor to control the magnitude of the oscillation. The voltage-variable resistor is part of a feedback control loop: Part of the output of the oscillator is rectified and filtered for use as a slow negative feedback to the gate of Q1 to keep the output amplitude constant. The response of this control loop is much slower than 2 kHz and, therefore, does not introduce significant distortion of the oscillator output, which is a fairly clean sine wave. The positive AC feedback needed to sustain oscillations is derived from sampling the current through the

  11. Upflow bioreactor having a septum and an auger and drive assembly

    Science.gov (United States)

    Hansen, Carl S.; Hansen, Conly L.

    2007-11-06

    An upflow bioreactor includes a vessel having an inlet and an outlet configured for upflow operation. A septum is positioned within the vessel and defines a lower chamber and an upper chamber. The septum includes an aperture that provides fluid communication between the upper chamber and lower chamber. The bioreactor also includes an auger positioned in the aperture of the septum. The vessel includes an opening in the top for receiving the auger. The auger extends from a drive housing, which is position over the opening and provides a seal around the opening. The drive housing is adjustable relative to the vessel. The position of the auger in the aperture can be adjusted by adjusting the drive housing relative to the vessel. The auger adjustment mechanism allows the auger to be accurately positioned within the aperture. The drive housing can also include a fluid to provide an additional seal around the shaft of the auger.

  12. Speed Control of Induction Motor using FOC Method

    Directory of Open Access Journals (Sweden)

    Hafeezul Haq

    2015-03-01

    Full Text Available An increasing number of applications in high performing electrical drive systems use nowadays, squirrel-cage induction motors. This paper describes a simplified method for the speed control of a three phase AC drive using Proportional-Integral controller. The simulation results show that the step response of the model is very fast, steady and able to work in four quadrants, and robustness and high performance is achieved.

  13. Effects of Lane Width, Lane Position and Edge Shoulder Width on Driving Behavior in Underground Urban Expressways: A Driving Simulator Study

    Science.gov (United States)

    Liu, Shuo; Wang, Junhua; Fu, Ting

    2016-01-01

    This study tested the effects of lane width, lane position and edge shoulder width on driving behavior for a three-lane underground urban expressway. A driving simulator was used with 24 volunteer test subjects. Five lane widths (2.85, 3.00, 3.25, 3.50, and 3.75 m) and three shoulder widths (0.50, 0.75, and 1.00 m) were studied. Driving speed, lane deviation and subjective perception of driving behavior were collected as performance measures. The results show that lane and shoulder width have significant effects on driving speed. Average driving speed increases from 60.01 km/h in the narrowest lane to 88.05 km/h in the widest lane. While both narrower lanes and shoulders result in reduced speed and lateral lane deviation, the effect of lane width is greater than that of shoulder width. When the lane and shoulder are narrow, drivers in the left or right lane tend to shy away from the tunnel wall, even encroaching into the neighboring middle lane. As the lane or shoulder gets wider, drivers tend to stay in the middle of the lane. An interesting finding is that although few participants acknowledged that lane position had any great bearing on their driving behaviors, the observed driving speed is statistically higher in the left lane than in the other two lanes when the lane width is narrow (in 2.85, 3 and 3.25 m lanes). These findings provided support for amending the current design specifications of urban underground roads, such as the relationship between design speed and lane width, speed limit, and combination form of lanes. PMID:27754447

  14. Effects of Lane Width, Lane Position and Edge Shoulder Width on Driving Behavior in Underground Urban Expressways: A Driving Simulator Study

    Directory of Open Access Journals (Sweden)

    Shuo Liu

    2016-10-01

    Full Text Available This study tested the effects of lane width, lane position and edge shoulder width on driving behavior for a three-lane underground urban expressway. A driving simulator was used with 24 volunteer test subjects. Five lane widths (2.85, 3.00, 3.25, 3.50, and 3.75 m and three shoulder widths (0.50, 0.75, and 1.00 m were studied. Driving speed, lane deviation and subjective perception of driving behavior were collected as performance measures. The results show that lane and shoulder width have significant effects on driving speed. Average driving speed increases from 60.01 km/h in the narrowest lane to 88.05 km/h in the widest lane. While both narrower lanes and shoulders result in reduced speed and lateral lane deviation, the effect of lane width is greater than that of shoulder width. When the lane and shoulder are narrow, drivers in the left or right lane tend to shy away from the tunnel wall, even encroaching into the neighboring middle lane. As the lane or shoulder gets wider, drivers tend to stay in the middle of the lane. An interesting finding is that although few participants acknowledged that lane position had any great bearing on their driving behaviors, the observed driving speed is statistically higher in the left lane than in the other two lanes when the lane width is narrow (in 2.85, 3 and 3.25 m lanes. These findings provided support for amending the current design specifications of urban underground roads, such as the relationship between design speed and lane width, speed limit, and combination form of lanes.

  15. The Drive to Influence

    Science.gov (United States)

    Rodriguez, Diego

    2017-01-01

    At the heart of the educational vocation is a drive to influence, to meaningfully affect the learning and development of others. For adult educators working in higher education, daily activities--from teaching classes to supervising student research to attending faculty meetings to sitting on advisory boards--are full of opportunities to…

  16. Driving with a Goat

    Institute of Scientific and Technical Information of China (English)

    高素菊

    2006-01-01

    <正>A highway patrol officer was sitting in his car beside the road one day when he noticed a man driving with a goat in the back seat of his car.Turning on the lights,he pulled out,sped up, and pulled the man over.

  17. Fresh Drive Against Corruption

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China’s government is making efforts to prevent corruption by taking harsh measures against the illegal selection and appointment of cadres on the 10th anniversary of China’s anti-corruption drive,President Hu Jintao called fogreater efforts to carry it out.

  18. Drugs and driving

    NARCIS (Netherlands)

    Walsh, J. Michael; De Gier, Johan J.; Christopherson, Asbjørg S.; Verstraete, Alain G.

    2004-01-01

    The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence-which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for futu

  19. Chaos in drive systems

    Directory of Open Access Journals (Sweden)

    Kratochvíl C.

    2007-10-01

    Full Text Available The purpose of this article is to provide an elementary introduction to the subject of chaos in the electromechanical drive systems. In this article, we explore chaotic solutions of maps and continuous time systems. These solutions are also bounded like equilibrium, periodic and quasiperiodic solutions.

  20. CSI: Hard Drive

    Science.gov (United States)

    Sturgeon, Julie

    2008-01-01

    Acting on information from students who reported seeing a classmate looking at inappropriate material on a school computer, school officials used forensics software to plunge the depths of the PC's hard drive, searching for evidence of improper activity. Images were found in a deleted Internet Explorer cache as well as deleted file space.…

  1. Risky Driving Behaviours among Medical Students in Erbil, Iraq

    Directory of Open Access Journals (Sweden)

    Nazar P. Shabila

    2015-08-01

    Full Text Available Objectives: This study aimed to assess risky driving behaviours among medical students in Erbil, Iraq, and to explore the relationship between risky driving behaviours and perceptions of risky driving. Methods: This self-administered questionnaire-based survey was conducted from January to May 2014 among a random sample of 400 medical students at Hawler Medical University in Erbil. The questionnaire was designed to assess the frequency of engagement in 21 risky driving behaviours, the perceived risk of each behaviour and the preference for each behaviour as ranked on a 5-point scale. Results: A total of 386 students responded to the survey (response rate: 96.5%. Of these, 211 reported that they currently drove a vehicle (54.7%. Drivers most frequently engaged in the following behaviours: playing loud music (35.9%, speeding (30.4%, allowing front seat passengers to not wear seat belts (27.9% and using mobile phones (27.7%. Least frequent driving behaviours included not stopping at a red light (3.9%, driving while sleepy (4.4%, driving after a mild to moderate intake of alcohol (4.5% and drunk driving (6.4%. Mean risky driving behaviour scores were significantly higher among males (P 20-year-olds (P = 0.028. There was a significant positive relationship between the preference for risky behaviours and risky driving behaviours (beta = 0.44; P <0.001. Conclusion: Medical students in Erbil reported high frequencies of several serious risky driving behaviours. The preference for risky behaviours was found to be an important predictor of risky driving behaviours among medical students in Erbil.

  2. Sensorless DC motor drive via optimal observer-based servo control

    Energy Technology Data Exchange (ETDEWEB)

    Thananchai Keephakpreeda [Thammasat University (Thailand). School of Industrial and Mechanical Engineering

    2002-07-01

    This paper proposes an alternative design of a sensorless DC motor drive via optimal observer-based servo control. Without the speed sensor, the extended Luenberger observer is implemented to estimate the rotor speed of the DC motor in the presence of the disturbance torque. With this knowledge of the speed estimated from the observer, the servo state-feedback controller can drive such a rotor speed to follow the desired one. The stability and performance of the DC drive system can be guaranteed by the optimal control which minimizes the H{sub 2} norm of the closed-loop feedback control and observer system. The simulation and experimental studies are demonstrated for the effectiveness of the proposed control methodology in a practical approach for the sensorless DC drive. (author)

  3. Variable speed induction motor operation from a 20-kHz power bus

    Science.gov (United States)

    Hansen, Irving G.

    Induction motors are recognized for their simple rugged construction to date, however, their application to variable speed or servo drives has been hampered by limitations on their control. Induction motor drives tend to be complex and to display troublesome low speed characteristics due in part to nonsinusoidal driving voltages. A technique was developed which involves direct synthesis of sinusoidal driving voltages from a high frequency power bus and independent control of frequency and voltages. Separation offrequency and voltage allows independent control of rotor and stator flux, full four-quadrant operation, and instantaneous torque control. Recent test results, current status of the technology, and proposed aerospace applications will be discussed.

  4. Easing the throttle in drive to work leaner.

    Science.gov (United States)

    Nuddell, Steve

    2010-10-01

    Steve Ruddell, division manager, Discrete Automation and Motion, at ABB, outlines the advantages of fitting variable speed drives and high efficiency motors into HVAC systems at a time when, faced with the need to cut costs, estates and facilities teams are having to look more closely than ever at reducing their buildings' energy consumption.

  5. More Than Just Speed

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The 1,318-km Beijing-Shanghai High-Speed Railway will finally come into operation at the end of June.Since construction began three years ago,the speedy railway has grabbed worldwide attention because of its design as the world’s longest and fastesthigh-speed rail line utilizing the most advanced technology.

  6. Speed enforcement in Norway

    DEFF Research Database (Denmark)

    Elvik, Rune

    2015-01-01

    This paper probes the relationship between changes in the risk of apprehension for speeding in Norway and changes in the amount of speeding. The paper is based on a game-theoretic model of how the rate of violations and the amount of enforcement is determined by the interaction between drivers...

  7. Effectiveness of Motorcycle speed controlled by speed hump

    Directory of Open Access Journals (Sweden)

    Pornsiri Urapa

    2014-09-01

    Full Text Available Speed humps are one of the traffic calming measures widely accepted to control vehicle speed in the local road. Humps standards from the western countries are designed mainly for the passenger car. This study, therefore, aims to reveal the effectiveness of speed hump to control the motorcycle speed. This study observes the free-flow speed of the riders at the total of 20 speed bumps and humps. They are 0.3-14.8 meter in width and 5-18 centimeter in height. The results reveal that the 85th percentile speeds reduce 15-65 percent when crossing the speed bumps and speed humps. Besides, this study develops the speed model to predict the motorcycle mean speed and 85th percentile speed. It is found that speed humps follow the ITE standard can control motorcycle crossing speeds to be 25-30 Kph which are suitable to travel on the local road.

  8. Investigation of numerical model of Lenze 530 Dc drive in Matlab

    OpenAIRE

    Golodnyi, І.; Lawrinenko, Yu.; Toropov, A.

    2014-01-01

    This paper describes DC drive with thyristor voltage regulator Lenze 530 series. To investigate the transients of the drive system developed numerical model in MatLab is developed. Dual circuit structural diagram of “TCV-DC motor” system with negative feedback for the current and angular speed or current and armature voltage in model is realized. By introduction of current feedback, torque and current limit are achieved and with using of armature voltage or tacho automatic speed stabili...

  9. Research on Predicting Drive Current of Shipborne Satcom Antenna

    Directory of Open Access Journals (Sweden)

    Kong Jinping

    2015-01-01

    Full Text Available Predicting the effect of antenna wind load on servo system precisely is meaningful to ensure the safety of satcom antenna on operation, which can avoid overload operation. In this paper, the computational fluid dynamics is used to proceed numerical computation on the pressure distribution of the reflector and torque of drive shaft under different wind speed, windward angle and angle of pitch of the antenna. The simulation model is built under MATLAB/Simulink simulation environment, and the drive current of the antenna servo system is analyzed under wind load effect and ship swing. Then, a method of predicting drive current of antenna servo system according to the wind speed, wind direction and attitude of the antenna is concluded. And this method is verified by simulation at last.

  10. Texting while driving: A study of 1211 U.S. adults with the Distracted Driving Survey.

    Science.gov (United States)

    Gliklich, Emily; Guo, Rong; Bergmark, Regan W

    2016-12-01

    Texting and other cell-phone related distracted driving is estimated to account for thousands of motor vehicle collisions each year but studies examining the specific cell phone reading and writing activities of drivers are limited. The objective of this study was to describe the frequency of cell-phone related distracted driving behaviors. A national, representative, anonymous panel of 1211 United States drivers was recruited in 2015 to complete the Distracted Driving Survey (DDS), an 11-item validated questionnaire examining cell phone reading and writing activities and at what speeds they occur. Higher DDS scores reflect more distraction. DDS scores were analyzed by demographic data and self-reported crash rate. Nearly 60% of respondents reported a cell phone reading or writing activity within the prior 30 days, with reading texts (48%), writing texts (33%) and viewing maps (43%) most frequently reported. Only 4.9% of respondents had enrolled in a program aimed at reducing cell phone related distracted driving. DDS scores were significantly correlated to crash rate (p driving.

  11. 全功率直驱永磁风力发电机组试验台的研究%Research for Full-Power Direct-Drive Permanent Magnet Wind Generator Set Electrical Test-Bed

    Institute of Scientific and Technical Information of China (English)

    罗百敏

    2011-01-01

    直驱型风力发电机组性能优越、运行可靠、维护简便.对采用的低速永磁电机矢量控制调速系统模拟直驱型风机的风轮运行特性进行了理论分析,提出大功率永磁同步发电机组交流传动系统仿真实际直驱永磁风力发电机组的技术方案,并设计和建立全功率直驱永磁风力发电机组的电气试验台.在试验台上对2 MW直驱永磁风力发电机组的电气系统进行了风机功率输出特性和模拟风况的运行性能的试验.%The direct-drive wind generator set has the advantages of superior performance, reliable running and easy maintenance. The theoretical analysis on wind turbine wheel running characteristics of low-speed permanent magnet motor vector control adjustable-speed system simulating direct-drive wind generator used was carried out and technical program of high-power permanent magnet synchronous generator set AC drive system to simulate actual direct-drive permanent magnet wind generator set was proposed, then electrical test bed of full-power direct-drive permanent magnet wind generator set was designed and built. Power output characteristics and running performance simulating wind condition test has been made for electrical system of 2 MW direct-drive permanent magnet wind generator set in test bed.

  12. Design of BLDCM Driving and Control System for Motorized Treadmill

    Institute of Scientific and Technical Information of China (English)

    Qi Zhang; Hui Li; Li-Bin Wang

    2007-01-01

    To satisfy the requirement of developing a new generation of motorized treadmill for a famous domestic manufacturer, a brushless DC motor (BLDCM) driving and control system for motorized treadmill is developed. High integration and reliability of this system are ensured under the condition that intelligent power module (TPM) is used and the protection module is included. Periodic current control method is applied to reduce the average current flowing through the armature winding of the motor when the treadmill is required to start with low speed while large load is added. Piecewise proportion-integration-differentiation (PID) control algorithm is applied to solve the problem of speed fluctuation when impulse load is added. The motorized treadmill of a new generation with the driving and control system has the advantages of high reliability, good speed stability, wide timing scope, low cost, and long life-span. And it is very promising for practical applications.

  13. Driving and engine cycles

    CERN Document Server

    Giakoumis, Evangelos G

    2017-01-01

    This book presents in detail the most important driving and engine cycles used for the certification and testing of new vehicles and engines around the world. It covers chassis and engine-dynamometer cycles for passenger cars, light-duty vans, heavy-duty engines, non-road engines and motorcycles, offering detailed historical information and critical review. The book also provides detailed examples from SI and diesel engines and vehicles operating during various cycles, with a focus on how the engine behaves during transients and how this is reflected in emitted pollutants, CO2 and after-treatment systems operation. It describes the measurement methods for the testing of new vehicles and essential information on the procedure for creating a driving cycle. Lastly, it presents detailed technical specifications on the most important chassis-dynamometer cycles around the world, together with a direct comparison of those cycles.

  14. Embodied linearity of speed control in Drosophila melanogaster.

    Science.gov (United States)

    Medici, V; Fry, S N

    2012-12-01

    Fruitflies regulate flight speed by adjusting their body angle. To understand how low-level posture control serves an overall linear visual speed control strategy, we visually induced free-flight acceleration responses in a wind tunnel and measured the body kinematics using high-speed videography. Subsequently, we reverse engineered the transfer function mapping body pitch angle onto flight speed. A linear model is able to reproduce the behavioural data with good accuracy. Our results show that linearity in speed control is realized already at the level of body posture-mediated speed control and is therefore embodied at the level of the complex aerodynamic mechanisms of body and wings. Together with previous results, this study reveals the existence of a linear hierarchical control strategy, which can provide relevant control principles for biomimetic implementations, such as autonomous flying micro air vehicles.

  15. Driving on the Descartes

    Science.gov (United States)

    1972-01-01

    Astronaut John W. Young, Apollo 16 mission commander, drives the 'Rover', Lunar Roving Vehicle (LRV) to its final parking place near the end of the third extravehicular activity (EVA-3) at the Descartes landing site. Astronaut Charles M. Duke Jr., Lunar Module pilot, took this photograph looking southward. The flank of Stone Mountain can be seen on the horizon at left. The shadow of the Lunar Module 'Orion' is visible in the foreground.

  16. Assessment of Lateral Driving Stability of Automobiles Passing by the Pylon Zone under Cross Wind

    Directory of Open Access Journals (Sweden)

    Dalei Wang

    2012-08-01

    Full Text Available In order to explore the reason of lateral instability of automobile passing by the pylon zone of cablesupported bridge under cross wind, a new evaluation method of lateral driving stability of automobile considering alternative cross wind is established based on multi-objective driving stability criteria and subjective assessment. Typical driving control process and dynamic response of automobile passing by the pylon zone is given by numerical simulation based on steering wheel fixed-control model and straight driving ideal-driver model. Finally, taking a medium-size commercial bus as an example, the reason of its lateral instability is interpreted and the influence of cross wind speed and driving speed on its lateral driving stability is shown by parameter study.

  17. 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 esti......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...

  18. Creating a driving profile for older adults using GPS devices and naturalistic driving methodology

    Science.gov (United States)

    Babulal, Ganesh M.; Traub, Cindy M.; Webb, Mollie; Stout, Sarah H.; Addison, Aaron; Carr, David B.; Ott, Brian R.; Morris, John C.; Roe, Catherine M.

    2016-01-01

    Background/Objectives: Road tests and driving simulators are most commonly used in research studies and clinical evaluations of older drivers. Our objective was to describe the process and associated challenges in adapting an existing, commercial, off-the-shelf (COTS), in-vehicle device for naturalistic, longitudinal research to better understand daily driving behavior in older drivers. Design: The Azuga G2 Tracking Device TM was installed in each participant’s vehicle, and we collected data over 5 months (speed, latitude/longitude) every 30-seconds when the vehicle was driven.  Setting: The Knight Alzheimer’s Disease Research Center at Washington University School of Medicine. Participants: Five individuals enrolled in a larger, longitudinal study assessing preclinical Alzheimer disease and driving performance.  Participants were aged 65+ years and had normal cognition. Measurements:  Spatial components included Primary Location(s), Driving Areas, Mean Centers and Unique Destinations.  Temporal components included number of trips taken during different times of the day.  Behavioral components included number of hard braking, speeding and sudden acceleration events. Methods:  Individual 30-second observations, each comprising one breadcrumb, and trip-level data were collected and analyzed in R and ArcGIS.  Results: Primary locations were confirmed to be 100% accurate when compared to known addresses.  Based on the locations of the breadcrumbs, we were able to successfully identify frequently visited locations and general travel patterns.  Based on the reported time from the breadcrumbs, we could assess number of trips driven in daylight vs. night.  Data on additional events while driving allowed us to compute the number of adverse driving alerts over the course of the 5-month period. Conclusions: Compared to cameras and highly instrumented vehicle in other naturalistic studies, the compact COTS device was quickly installed and transmitted high volumes

  19. Metric-adjusted skew information

    DEFF Research Database (Denmark)

    Liang, Cai; Hansen, Frank

    2010-01-01

    We give a truly elementary proof of the convexity of metric-adjusted skew information following an idea of Effros. We extend earlier results of weak forms of superadditivity to general metric-adjusted skew information. Recently, Luo and Zhang introduced the notion of semi-quantum states...... on a bipartite system and proved superadditivity of the Wigner-Yanase-Dyson skew informations for such states. We extend this result to the general metric-adjusted skew information. We finally show that a recently introduced extension to parameter values 1 information is a special case...... of (unbounded) metric-adjusted skew information....

  20. Convexity Adjustments for ATS Models

    DEFF Research Database (Denmark)

    Murgoci, Agatha; Gaspar, Raquel M.

    Practitioners are used to value a broad class of exotic interest rate derivatives simply by preforming for what is known as convexity adjustments (or convexity corrections). We start by exploiting the relations between various interest rate models and their connections to measure changes. As a re......Practitioners are used to value a broad class of exotic interest rate derivatives simply by preforming for what is known as convexity adjustments (or convexity corrections). We start by exploiting the relations between various interest rate models and their connections to measure changes....... As a result we classify convexity adjustments into forward adjustments and swaps adjustments. We, then, focus on affine term structure (ATS) models and, in this context, conjecture convexity adjustments should be related of affine functionals. In the case of forward adjustments, we show how to obtain exact...... formulas. Concretely for LIBOR in arrears (LIA) contracts, we derive the system of Riccatti ODE-s one needs to compute to obtain the exact adjustment. Based upon the ideas of Schrager and Pelsser (2006) we are also able to derive general swap adjustments useful, in particular, when dealing with constant...