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Sample records for adaptive robotic welding

  1. Infrared sensing techniques for adaptive robotic welding

    International Nuclear Information System (INIS)

    Lin, T.T.; Groom, K.; Madsen, N.H.; Chin, B.A.

    1986-01-01

    The objective of this research is to investigate the feasibility of using infrared sensors to monitor the welding process. Data were gathered using an infrared camera which was trained on the molten metal pool during the welding operation. Several types of process perturbations which result in weld defects were then intentionally induced and the resulting thermal images monitored. Gas tungsten arc using ac and dc currents and gas metal arc welding processes were investigated using steel, aluminum and stainless steel plate materials. The thermal images obtained in the three materials and different welding processes revealed nearly identical patterns for the same induced process perturbation. Based upon these results, infrared thermography is a method which may be very applicable to automation of the welding process

  2. Adaptive control of penetration and joint following for robotic GTA welding

    International Nuclear Information System (INIS)

    Bahram Mir Sadeghi; Hishamuddin Jamaludin; Iskandar Baharin

    1997-01-01

    A statistical-based method for adaptive control of weld pool penetration and joint following in Tungsten Inert Gas Welding as an approach to process and trajectory control of robotic GTA welding has been designed and simulated. Welding process parameters such as: base current and time, pulse current and time, electrode tip to work piece distance, filler travelling speed, torch speed and work piece thickness were used for finding the equations which describe the interrelationship between the aforementioned variables and penetration depth as well as bead width. The calculation of these equations was developed from the statistical regression analysis of 80 welds deposited using various combinations of welding parameters. For monitoring of the work piece thickness variations, an ultrasonic device was used. In order to control the weld trajectory, a CCD camera was also used. The results showed that the misalignment of the progressive heat affected zone which is adjacent to the weld puddle can be detected, and used for control of the weld trajectory. Also, it was found that scanning of a certain region of the captured image in front of the weld puddle decreases the data processing time drastically

  3. Mechanized hyperbaric welding by robots

    International Nuclear Information System (INIS)

    Aust, E.; Santos, J.F. dos; Bohm, K.H.; Hensel, H.D.

    1988-01-01

    At the GKSS-Forschungszentrum investigations are carried out on mechanized welded test plates produced under working pressure between 10 to 110 bar in breathable TRIMIX-5-atmosphere. The welds are performed by a modified industrial robot, which was adapted in its components to withstand these severe conditions. Variations on the welding parameters were made to maintain a stable arc as well as to provide on indication of the effect of the variables on the mechanical properties of the welded joint. During all tests the robot showed a very good function. Good reliable welds were achieved meeting the requirements according API II04 or BS 4515-1984. (orig.) [de

  4. Robot welding process control

    Science.gov (United States)

    Romine, Peter L.

    1991-01-01

    This final report documents the development and installation of software and hardware for Robotic Welding Process Control. Primary emphasis is on serial communications between the CYRO 750 robotic welder, Heurikon minicomputer running Hunter & Ready VRTX, and an IBM PC/AT, for offline programming and control and closed-loop welding control. The requirements for completion of the implementation of the Rocketdyne weld tracking control are discussed. The procedure for downloading programs from the Intergraph, over the network, is discussed. Conclusions are made on the results of this task, and recommendations are made for efficient implementation of communications, weld process control development, and advanced process control procedures using the Heurikon.

  5. Integrated sensors for robotic laser welding

    NARCIS (Netherlands)

    Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Beyer, E.; Dausinger, F; Ostendorf, A; Otto, A.

    2005-01-01

    A welding head is under development with integrated sensory systems for robotic laser welding applications. Robotic laser welding requires sensory systems that are capable to accurately guide the welding head over a seam in three-dimensional space and provide information about the welding process as

  6. Sensor integration for robotic laser welding processes

    NARCIS (Netherlands)

    Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Ostendorf, A; Hoult, A.; Lu, Y.

    2005-01-01

    The use of robotic laser welding is increasing among industrial applications, because of its ability to weld objects in three dimensions. Robotic laser welding involves three sub-processes: seam detection and tracking, welding process control, and weld seam inspection. Usually, for each sub-process,

  7. Welding robot package; Arc yosetsu robot package

    Energy Technology Data Exchange (ETDEWEB)

    Nishikawa, S. [Yaskawa Electric Corp., Kitakyushu (Japan)

    1998-09-01

    For the conventional high-speed welding robot, the welding current was controlled mainly for reducing the spatters during short circuits and for stabilizing the beads by the periodic short circuits. However, an increase of deposition amount in response to the speed is required for the high-speed welding. Large-current low-spatter welding current region control was added. Units were integrated into a package by which the arc length is kept in short without dispersion of arc length for welding without defects such as undercut and unequal beads. In automobile industry, use of aluminum parts is extended for the light weight. The welding is very difficult, and automation is not so progressing in spite of the poor environment. Buckling of welding wire is easy to occur, and supply of wire is obstructed by the deposition of chipped powders on the torch cable, which stay within the contact chip resulting in the deposition. Dislocation of locus is easy to occur at the corner of rectangular pipe during the welding. By improving these troubles, an aluminum MIG welding robot package has been developed. 13 figs.

  8. An Adaptive Robot Game

    DEFF Research Database (Denmark)

    Hansen, Søren Tranberg; Svenstrup, Mikael; Dalgaard, Lars

    2010-01-01

    The goal of this paper is to describe an adaptive robot game, which motivates elderly people to do a regular amount of physical exercise while playing. One of the advantages of robot based games is that the initiative to play can be taken autonomously by the robot. In this case, the goal is to im......The goal of this paper is to describe an adaptive robot game, which motivates elderly people to do a regular amount of physical exercise while playing. One of the advantages of robot based games is that the initiative to play can be taken autonomously by the robot. In this case, the goal...... is to improve the mental and physical state of the user by playing a physical game with the robot. Ideally, a robot game should be simple to learn but difficult to master, providing an appropriate degree of challenge for players with different skills. In order to achieve that, the robot should be able to adapt...

  9. A System for Complex Robotic Welding

    DEFF Research Database (Denmark)

    Madsen, Ole; Sørensen, Carsten Bro; Olsen, Birger

    2002-01-01

    This paper presents the architecture of a system for robotic welding of complex tasks. The system integrates off-line programming, control of redundant robots, collision-free motion planning and sensor-based control. An implementation for pipe structure welding made at Odense Steel Shipyard Ltd......., Denmark, demonstrates the system can be used for automatic welding of complex products in one-of-a-kind production....

  10. Welding Robot Collision-Free Path Optimization

    Directory of Open Access Journals (Sweden)

    Xuewu Wang

    2017-02-01

    Full Text Available Reasonable welding path has a significant impact on welding efficiency, and a collision-free path should be considered first in the process of welding robot path planning. The shortest path length is considered as an optimization objective, and obstacle avoidance is considered as the constraint condition in this paper. First, a grid method is used as a modeling method after the optimization objective is analyzed. For local collision-free path planning, an ant colony algorithm is selected as the search strategy. Then, to overcome the shortcomings of the ant colony algorithm, a secondary optimization is presented to improve the optimization performance. Finally, the particle swarm optimization algorithm is used to realize global path planning. Simulation results show that the desired welding path can be obtained based on the optimization strategy.

  11. Modeling of welded bead profile for rapid prototyping by robotic MAG welding

    Institute of Scientific and Technical Information of China (English)

    CAO Yong; ZHU Sheng; WANG Tao; WANG Wanglong

    2009-01-01

    As a deposition technology, robotic metal active gas(MAG) welding has shown new promise for rapid prototyping (RP) of metallic parts. During the process of metal forming using robotic MAG welding, sectional profile of single-pass welded bead is critical to formed accuracy and quality of metal pans. In this paper, the experiments of single-pass welded bead for rapid prototyping using robotic MAG welding were carried out. The effect of some edge detectors on the cross-sectional edge of welded bead was discussed and curve fitting was applied using leat square fitting. Consequently, the mathematical model of welded bead profile was developed. The experimental results show that good shape could be obtained under suitable welding parameters. Canny operawr is suitable to edge detection of welded bead profile, and the mathematical model of welded bead profile developed is approximately parabola.

  12. Mechanical and electrochemical characteristics with welding materials in robotic MIG welding of dissimilar Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Jong; Han, Min Su; Woo, Yong Bin [Mokpo Maritime Univ., Mokpo (Korea, Republic of)

    2013-05-15

    In this study, mechanical and electrochemical characteristics with welding material in MIG welded with ROBOT for dissimilar Al alloys were investigated using various experiment methods. The MIG welding by ROBOT with ER5183 and ER5556 for the 5456-H116 and 6061-T6 Al alloy were carried out. The hardness of welding zone was lower than that of base metal. In electrochemical experiment, ER5183 welding material presented excellent characteristics. The yield strength and maximum tensile strength in welding with welding material of ER5183 presented lower value than those of ER5556. The elongation and time-to-fracture showed the opposite results.

  13. Rapid prototyping using robot welding : process description

    OpenAIRE

    Ribeiro, António Fernando; Norrish, John

    1997-01-01

    Rapid Prototyping is a relatively recent technique to produce component prototypes for industry in a much shorter period of time, since the time to market a product is essential to its success. A new Rapid Prototyping process which uses metal as the raw material had been under development at Cranfield University in the last few years. The process uses a Gas Metal Arc fusion welding robot which deposits successive layers of metal in such way that it forms a 3D solid component. Firstly, a CAD s...

  14. Development of underwater YAG laser repair welding robots for tanks

    International Nuclear Information System (INIS)

    Miwa, Yasuhiro; Satoh, Syuichi; Ito, Kosuke; Kochi, Tsutomu; Kojima, Toshio; Ohwaki, Katsura; Morita, Ichiro

    1999-01-01

    A remote-controlled repair welding robot which uses YAG laser welding technology in underwater environment was developed. This is an underwater robot technology combined with a laser welding technology. This report will describe the structure and performance of this robot, and the welding test results. The repair welding robot consists of two parts. The one is driving equipment, and the other is welding unit. It can swim in the tank, move around the tank wall, and stay on the welding area. After that it starts YAG laser repair welding. The target of this technology is inner surface repair of some tanks made of austenitic stainless steel, for example RW (Radioactive Waste) tanks. A degradation by General Corrosion and so on might be occurred at inner surface of these tanks in BWR type nuclear power plants. If the damaged area is wide, repair welding works are done. Some workers go into the tank and set up scaffolding after full drainage. In many cases it spends too much time for draining water and repair welding preparation. If the repair welding works can be done in underwater environment, the outage period will be reduced. This is a great advantage. (author)

  15. Sensor controlled robotic welding for nuclear applications. Annual progress report

    International Nuclear Information System (INIS)

    Chin, B.A.; Madsen, N.H.; Goodling, J.S.

    1986-01-01

    Significant accomplishments towards the development of an adaptive robotic welding system have been made during the first eight months of the project. The project is currently within budget and on schedule. Accomplishments were both scientific and programmatic in form. A list of the scientific accomplishments follows: demonstrated that the thermal profiles generated for intentionally induced defects during the welding process are similar in steel, aluminum and stainless steel. The conclusion is therefore that infrared sensing is applicable to the welding of over 90% of all materials used in the energy industry. Completed design and testing of a first generation communication system used to transfer information from the infrared camera to the computer in a near real time form. This demonstrates that information can be obtained, sorted, transferred and received in a time frame consistent with on-line process control. Demonstrated rudimentary seam tracking using infrared sensing and closed loop logic routines. A linear relationship exists between measured peak surface temperature and depth of penetration. Similarily, a linear relationship exists between measured infrared width and weld bead width. These relations suggest that penetration parameters may be controlled using surface measurements as obtained by infrared thermography

  16. Optimization of process parameters in welding of dissimilar steels using robot TIG welding

    Science.gov (United States)

    Navaneeswar Reddy, G.; VenkataRamana, M.

    2018-03-01

    Robot TIG welding is a modern technique used for joining two work pieces with high precision. Design of Experiments is used to conduct experiments by varying weld parameters like current, wire feed and travelling speed. The welding parameters play important role in joining of dissimilar stainless steel SS 304L and SS430. In this work, influences of welding parameter on Robot TIG Welded specimens are investigated using Response Surface Methodology. The Micro Vickers hardness tests of the weldments are measured. The process parameters are optimized to maximize the hardness of the weldments.

  17. Spline-based automatic path generation of welding robot

    Institute of Scientific and Technical Information of China (English)

    Niu Xuejuan; Li Liangyu

    2007-01-01

    This paper presents a flexible method for the representation of welded seam based on spline interpolation. In this method, the tool path of welding robot can be generated automatically from a 3D CAD model. This technique has been implemented and demonstrated in the FANUC Arc Welding Robot Workstation. According to the method, a software system is developed using VBA of SolidWorks 2006. It offers an interface between SolidWorks and ROBOGUIDE, the off-line programming software of FANUC robot. It combines the strong modeling function of the former and the simulating function of the latter. It also has the capability of communication with on-line robot. The result data have shown its high accuracy and strong reliability in experiments. This method will improve the intelligence and the flexibility of the welding robot workstation.

  18. Remote machining and robotic welding in a proton cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, W; Mark, C

    1984-09-01

    Increasing residual radiation in the TRIUMF meson research facility cyclotron at the University of British Columbia has required development of a remotely operable industrial robot cutting and vacuum tight welding capabili

  19. Recognition and automatic tracking of weld line in fringe welding by autonomous mobile robot with visual sensor

    International Nuclear Information System (INIS)

    Suga, Yasuo; Saito, Keishin; Ishii, Hideaki.

    1994-01-01

    An autonomous mobile robot with visual sensor and four driving axes for welding of pipe and fringe was constructed. The robot can move along a pipe, and detect the weld line to be welded by visual sensor. Moreover, in order to perform welding automatically, the tip of welding torch can track the weld line of the joint by rotating the robot head. In the case of welding of pipe and fringe, the robot can detect the contact angle between the two base metals to be welded, and the torch angle changes according to the contact angle. As the result of tracking test by the robot system, it was made clear that the recognition of geometry of the joint by the laser lighting method and automatic tracking of weld line were possible. The average tracking error was ±0.3 mm approximately and the torch angle could be always kept at the optimum angle. (author)

  20. Sensor development and integration for robotized laser welding

    NARCIS (Netherlands)

    Iakovou, D.

    2009-01-01

    Laser welding requires fast and accurate positioning of the laser beam over the seam trajectory. The task of accurate positioning of the laser tools is performed by robotic systems. It is therefore necessary to teach the robot the path it has to follow. Seam teaching is implemented in several ways:

  1. Quality assurance and control for robotic GMA welding

    International Nuclear Information System (INIS)

    Xie Max X.

    1992-01-01

    A quality assurance (QA) model has been developed. This model systematically considers the relevant activities before, during and after the welding operations with respect to quality. Efficient quality assurance requires that the functionality of the present robotic welding systems needs to be increased and that the knowledge of the personnel involved in the design and production needs to be improved. The collaboration between different departments and personnel needs also to be improved. The procedure specification aspects have been studied and a method for the determination of optimal welding parameters is presented with regards to process stability, quality requirements and productivity. A main productivity problem of robotic welding systems for small series production is due to the time spent on the specification of welding procedures. In order to improve the efficiency, expert systems technology has been studied and applied to automatically generate optimal welding procedures. An objective method for the assessment of process stability has been developed, based upon the analysis of the electrical signals of welding arcs. Furthermore, a method has been developed to monitor the process stability. It is found that it is possible to identify the causes of the disturbance of process stability and to predict the weld quality characteristics based on the analysis of the electrical signals. Though quality is formed during the welding operation, the diagnosis of the causes of quality disturbances is important for the prevention of quality problems of subsequent welds and has been discussed. To assist the operators, expert systems technology is also applied. Further work should be directed to the integration of various QA functions in the robotic arc welding system so that both quality and productivity aspects of the system ban be further improved. (au)

  2. Adaptive Behavior for Mobile Robots

    Science.gov (United States)

    Huntsberger, Terrance

    2009-01-01

    The term "System for Mobility and Access to Rough Terrain" (SMART) denotes a theoretical framework, a control architecture, and an algorithm that implements the framework and architecture, for enabling a land-mobile robot to adapt to changing conditions. SMART is intended to enable the robot to recognize adverse terrain conditions beyond its optimal operational envelope, and, in response, to intelligently reconfigure itself (e.g., adjust suspension heights or baseline distances between suspension points) or adapt its driving techniques (e.g., engage in a crabbing motion as a switchback technique for ascending steep terrain). Conceived for original application aboard Mars rovers and similar autonomous or semi-autonomous mobile robots used in exploration of remote planets, SMART could also be applied to autonomous terrestrial vehicles to be used for search, rescue, and/or exploration on rough terrain.

  3. Work organisation and quality control in a welding robotic cell

    OpenAIRE

    Moniz, António

    1993-01-01

    In this paper is analyzed the work organization and the forms of quality control in a robotic welding station in a company of office equipment and metal components manufacturing. The robotic cell is recent and works in two shifts. Quality and production rationalization implied in this firms the adoption of a strategy of organization of teamwork, and it is supported the collaborative tools to decrease the possibilities for errors and to improve means and methods of manufacturing. The analysis ...

  4. Remote machining and robotic welding in a proton cyclotron

    International Nuclear Information System (INIS)

    Cameron, W.; Mark, C.

    1984-01-01

    Increasing residual radiation in the TRIUMF meson research facility cyclotron at the University of British Columbia has required development of a remotely operable industrial robot cutting and vacuum tight welding capability for modification and updating of vacuum tank access ports, and for possible repairs of leaks or holes in the vacuum tank periphery

  5. Sensor based robot laser welding - based on feed forward and gain sceduling algorithms

    DEFF Research Database (Denmark)

    Andersen, Henrik John

    2001-01-01

    A real-time control system forlaser welding of thick steel plates are developed and tested in a industrial environment. The robotic execution of the laser welding process is based on measure weld joint geometry and impirically established welding procedures. The influence of industrial production...

  6. Robotic weld overlay coatings for erosion control

    Science.gov (United States)

    The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

  7. Truss Assembly and Welding by Intelligent Precision Jigging Robots

    Science.gov (United States)

    Komendera, Erik; Dorsey, John T.; Doggett, William R.; Correll, Nikolaus

    2014-01-01

    This paper describes an Intelligent Precision Jigging Robot (IPJR) prototype that enables the precise alignment and welding of titanium space telescope optical benches. The IPJR, equipped with micron accuracy sensors and actuators, worked in tandem with a lower precision remote controlled manipulator. The combined system assembled and welded a 2 m truss from stock titanium components. The calibration of the IPJR, and the difference between the predicted and the truss dimensions as-built, identified additional sources of error that should be addressed in the next generation of IPJRs in 2D and 3D.

  8. Study on Intelligent Control of Metal Filling System by Welding Robots in the Open Environment

    Directory of Open Access Journals (Sweden)

    Wei Fu

    2014-08-01

    Full Text Available robot model of three-arm and five-degree freedom plus large scope of traversing welding was established, and decoupling of models of “large scope of traversing”, “triangle movement of two arms” and “spherical movement of one arm” was realized. The model of “triangle movement of two arms ”is able to use geometrical calculation to solve the kinematics inverse problem , avoid the multiplicity, improve the calculation speed, eliminate the blind spots of the motions of welding gun of welding robot, and simplify the kinematic pair of kinematic mechanism for the arc filling strategy during welding travelling of robot. Binocular stereo vision camera was used to detect the edges of welds, and laser array sensor was used to detect the amount of metal filling of welds. In completely open conditions, feedback was fused based on sensor data to realize the welding tracking control by welding robot.

  9. Mechanized and robotized welding in shipbuilding; Zosen ni okeru yosetsu no jidoka robot ka

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1997-12-01

    Large-scale ships such as VLCC are built at the Kure No.1 Works of IHI (Ishikawajima-Harima Heavy Industry). This paper introduces current status of mechanized and robotized welding at the works. For the sub-assembly with short weld length and horizontal fillet, simplified automatic welders are used in which mag-welding method using CO2 is adopted. The frequent wound welding of member ends can be automatically conducted using welders developed by IHI. In the large-scale assembly processes, remarkable rationalization and highly accurate assembly of flat plate welding have been promoted. Tankers, container ships, and bulk carriers can be treated at the same time. Teaching times of welding robots can be greatly reduced by a technique called parametric treatment. In the future, it is essential to enhance the accuracy of members by introducing the laser cutting during machining processes. Completely self-type mechanization is required as well as large-output laser welding and sensor technology. 3 refs., 12 figs., 2 tabs.

  10. Development of sensor augmented robotic weld systems for aerospace propulsion system fabrication

    Science.gov (United States)

    Jones, C. S.; Gangl, K. J.

    1986-01-01

    In order to meet stringent performance goals for power and reuseability, the Space Shuttle Main Engine was designed with many complex, difficult welded joints that provide maximum strength and minimum weight. To this end, the SSME requires 370 meters of welded joints. Automation of some welds has improved welding productivity significantly over manual welding. Application has previously been limited by accessibility constraints, requirements for complex process control, low production volumes, high part variability, and stringent quality requirements. Development of robots for welding in this application requires that a unique set of constraints be addressed. This paper shows how robotic welding can enhance production of aerospace components by addressing their specific requirements. A development program at the Marshall Space Flight Center combining industrial robots with state-of-the-art sensor systems and computer simulation is providing technology for the automation of welds in Space Shuttle Main Engine production.

  11. A robotic platform for laser welding of corneal tissue

    Science.gov (United States)

    Rossi, Francesca; Micheletti, Filippo; Magni, Giada; Pini, Roberto; Menabuoni, Luca; Leoni, Fabio; Magnani, Bernardo

    2017-07-01

    Robotic surgery is a reality in several surgical fields, such as in gastrointestinal surgery. In ophthalmic surgery the required high spatial precision is limiting the application of robotic system, and even if several attempts have been designed in the last 10 years, only some application in retinal surgery were tested in animal models. The combination of photonics and robotics can really open new frontiers in minimally invasive surgery, improving the precision, reducing tremor, amplifying scale of motion, and automating the procedure. In this manuscript we present the preliminary results in developing a vision guided robotic platform for laser-assisted anterior eye surgery. The robotic console is composed by a robotic arm equipped with an "end effector" designed to deliver laser light to the anterior corneal surface. The main intended application is for laser welding of corneal tissue in laser assisted penetrating keratoplasty and endothelial keratoplasty. The console is equipped with an integrated vision system. The experiment originates from a clear medical demand in order to improve the efficacy of different surgical procedures: when the prototype will be optimized, other surgical areas will be included in its application, such as neurosurgery, urology and spinal surgery.

  12. Robots that can adapt like animals.

    Science.gov (United States)

    Cully, Antoine; Clune, Jeff; Tarapore, Danesh; Mouret, Jean-Baptiste

    2015-05-28

    Robots have transformed many industries, most notably manufacturing, and have the power to deliver tremendous benefits to society, such as in search and rescue, disaster response, health care and transportation. They are also invaluable tools for scientific exploration in environments inaccessible to humans, from distant planets to deep oceans. A major obstacle to their widespread adoption in more complex environments outside factories is their fragility. Whereas animals can quickly adapt to injuries, current robots cannot 'think outside the box' to find a compensatory behaviour when they are damaged: they are limited to their pre-specified self-sensing abilities, can diagnose only anticipated failure modes, and require a pre-programmed contingency plan for every type of potential damage, an impracticality for complex robots. A promising approach to reducing robot fragility involves having robots learn appropriate behaviours in response to damage, but current techniques are slow even with small, constrained search spaces. Here we introduce an intelligent trial-and-error algorithm that allows robots to adapt to damage in less than two minutes in large search spaces without requiring self-diagnosis or pre-specified contingency plans. Before the robot is deployed, it uses a novel technique to create a detailed map of the space of high-performing behaviours. This map represents the robot's prior knowledge about what behaviours it can perform and their value. When the robot is damaged, it uses this prior knowledge to guide a trial-and-error learning algorithm that conducts intelligent experiments to rapidly discover a behaviour that compensates for the damage. Experiments reveal successful adaptations for a legged robot injured in five different ways, including damaged, broken, and missing legs, and for a robotic arm with joints broken in 14 different ways. This new algorithm will enable more robust, effective, autonomous robots, and may shed light on the principles

  13. Research on Kinematic Trajectory Simulation System of KUKA Arc Welding Robot System

    Science.gov (United States)

    Hu, Min

    2017-10-01

    In this paper, the simulation trajectory simulation of KUKA arc welding robot system is realized by means of VC platform. It is used to realize the teaching of professional training of welding robot in middle school. It provides teaching resources for the combination of work and study and integration teaching, which enriches the content of course teaching.

  14. Robotic Assistance by Impedance Compensation for Hand Movements While Manual Welding.

    Science.gov (United States)

    Erden, Mustafa Suphi; Billard, Aude

    2016-11-01

    In this paper, we present a robotic assistance scheme which allows for impedance compensation with stiffness, damping, and mass parameters for hand manipulation tasks and we apply it to manual welding. The impedance compensation does not assume a preprogrammed hand trajectory. Rather, the intention of the human for the hand movement is estimated in real time using a smooth Kalman filter. The movement is restricted by compensatory virtual impedance in the directions perpendicular to the estimated direction of movement. With airbrush painting experiments, we test three sets of values for the impedance parameters as inspired from impedance measurements with manual welding. We apply the best of the tested sets for assistance in manual welding and perform welding experiments with professional and novice welders. We contrast three conditions: 1) welding with the robot's assistance; 2) with the robot when the robot is passive; and 3) welding without the robot. We demonstrate the effectiveness of the assistance through quantitative measures of both task performance and perceived user's satisfaction. The performance of both the novice and professional welders improves significantly with robotic assistance compared to welding with a passive robot. The assessment of user satisfaction shows that all novice and most professional welders appreciate the robotic assistance as it suppresses the tremors in the directions perpendicular to the movement for welding.

  15. Adaptive Control Methods for Soft Robots

    Data.gov (United States)

    National Aeronautics and Space Administration — I propose to develop methods for soft and inflatable robots that will allow the control system to adapt and change control parameters based on changing conditions...

  16. Adaptive heterogeneous multi-robot teams

    Energy Technology Data Exchange (ETDEWEB)

    Parker, L.E.

    1998-11-01

    This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. The author describes a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, the author describes in detail the experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability of ALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team.

  17. Underwater welding using remote controlled robots. Development of remote underwater welding technology with a high power YAG laser

    International Nuclear Information System (INIS)

    Miwa, Yasuhiro; Sato, Syuuichi; Kojima, Toshio; Owaki, Katsura; Hirose, Naoya

    2002-01-01

    As components in nuclear power plant have been periodically carried out their inspection and repair to keep their integrity, on radioactive liquid wastes storage facility, because of difficulty on their inspection by human beings, some are remained without inspection, and even when capable of inspection, conversion from human works to remote operations is desired from a viewpoint of their operation efficiency upgrading. For response to these needs, some developments on a technology capable of carrying out inspection of their inside at underwater environment and repairing welding with YAG laser by means of remote operation, have been performed. Remote underwater inspection and repair technology is a combination technology of already applied underwater mobile technique (underwater inspection robot) with underwater YAG laser welding technique which is recently at actual using level. Therefore, this technology is composed of an inspection robot and a repair welding robot. And, testing results using the underwater inspection robot and welding test results using the underwater repair welding robot, were enough preferable to obtain forecasting applicable to actual apparatuses. This technology is especially effective for inspection and repair of inside of nuclear fuel cycle apparatuses and relatively high dose apparatuses, and can be thought to be applicable also to large capacity tanks, tanks dealing with harmful matters, underwater structures, and so on, in general industries. (G.K.)

  18. IMPROVEMENT OF WELDED CONNECTIONS WITH SIDE LAP WELDS BY REDISTRIBUTION OF ALL-WELD METAL ALONG LENGTHS AND CROSS-SECTIONS THEREOF USING MECHANIZED AND ROBOTIC WELDING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Pavlov Evgeniy Igorevich

    2017-05-01

    Full Text Available Experimental study of bearing capacity of samples of two series performed by semiautomatic welding in CO2 on the axis, and by robotic welding machine in mixture (CO2 + Ar, is presented. Welds of constant cross section, welds with extended leg on end sections, and welds in the form of two dowels on end sections were performed. Efficiency of pilot samples of the first series (with extended leg on end sections by way of a smooth transition defined by the ratio of weld metal volume to a crushing load reaches 28 % relative to samples with a leg constant as per length. Samples of the first series with an extended leg on end sections also showed efficiency increased to 17 %. According to the second series samples test results, the exceeding of bearing capacity of the samples performed with an extended leg on end sections by 24 % in comparison with the samples with a leg of constant cross section was determined. Samples of the second series performed in the form of two dowels on end sections demonstrated the exceeding of the relative bearing capacity by 42 % in comparison with the samples with a continuous leg of constant cross-section.

  19. Intelligent Control of Welding Gun Pose for Pipeline Welding Robot Based on Improved Radial Basis Function Network and Expert System

    Directory of Open Access Journals (Sweden)

    Jingwen Tian

    2013-02-01

    Full Text Available Since the control system of the welding gun pose in whole-position welding is complicated and nonlinear, an intelligent control system of welding gun pose for a pipeline welding robot based on an improved radial basis function neural network (IRBFNN and expert system (ES is presented in this paper. The structure of the IRBFNN is constructed and the improved genetic algorithm is adopted to optimize the network structure. This control system makes full use of the characteristics of the IRBFNN and the ES. The ADXRS300 micro-mechanical gyro is used as the welding gun position sensor in this system. When the welding gun position is obtained, an appropriate pitch angle can be obtained through expert knowledge and the numeric reasoning capacity of the IRBFNN. ARM is used as the controller to drive the welding gun pitch angle step motor in order to adjust the pitch angle of the welding gun in real-time. The experiment results show that the intelligent control system of the welding gun pose using the IRBFNN and expert system is feasible and it enhances the welding quality. This system has wide prospects for application.

  20. Robust Control of Welding Robot for Tracking a Rectangular Welding Line

    Directory of Open Access Journals (Sweden)

    Manh Dung Ngo

    2008-11-01

    Full Text Available This paper highlights a welding robot (WR for its end effector to track a rectangular welding line (RWL. The WR includes five actuators which use a DC motor as a power source. Two controllers are proposed to control the WR's end effector: a main controller and a servo controller. Firstly, based on WR's kinematic equations and its feedback errors using backstepping method the main controller is proposed to design the reference-inputs for the WR's actuators in order that the WR's end effector tracks the RWL. Secondly, based on the dynamic equation of WR's actuator, the servo controller is designed using an active disturbance rejection control method. Finally, a control system incorporated with the main controller and the servo controllers make the WR's end effector robustly track a RWL in the presence of the modeling uncertainty and disturbances during the welding process. In experiment, the main controller which has a function as a master of the control system links to the five servo controllers which have a function as a slave via I2C communication. The effectiveness of the proposed control system is proven through the simulation and experimental results.

  1. Robust Control of Welding Robot for Tracking a Rectangular Welding Line

    Directory of Open Access Journals (Sweden)

    Manh Dung Ngo

    2006-09-01

    Full Text Available This paper highlights a welding robot (WR for its end effector to track a rectangular welding line (RWL. The WR includes five actuators which use a DC motor as a power source. Two controllers are proposed to control the WR's end effector: a main controller and a servo controller. Firstly, based on WR's kinematic equations and its feedback errors using backstepping method the main controller is proposed to design the reference-inputs for the WR's actuators in order that the WR's end effector tracks the RWL. Secondly, based on the dynamic equation of WR's actuator, the servo controller is designed using an active disturbance rejection control method. Finally, a control system incorporated with the main controller and the servo controllers make the WR's end effector robustly track a RWL in the presence of the modeling uncertainty and disturbances during the welding process. In experiment, the main controller which has a function as a master of the control system links to the five servo controllers which have a function as a slave via I2C communication. The effectiveness of the proposed control system is proven through the simulation and experimental results.

  2. Strength analysis and optimization of welding robot mechanism in emergency stop state

    OpenAIRE

    Zdeněk Poruba; Jiří Podešva; Ondřej František; Martin Fusek; Robert Brázda; Marek Sadílek

    2016-01-01

    The contribution deals with the strength analysis and optimization of the welding robot mechanism in emergency stop state. The common operational positioning of the welding robot is characterized by smooth course of speeds in the time. The resulting load does not differ significantly from the static loading. However the safety requirements given by the norm require the ability of emergency stop function. Since the course of speed in time is rather steep the higher values of acceleration and t...

  3. Adaptive Nonlinear Tracking for Robotic Walking

    Czech Academy of Sciences Publication Activity Database

    Dolinský, Kamil; Čelikovský, Sergej

    2012-01-01

    Roč. 1, č. 1 (2012), s. 28-35 ISSN 2223-7038 Institutional research plan: CEZ:AV0Z10750506 Keywords : Adaptive control * Kalman filter * walking robots Subject RIV: BC - Control Systems Theory http://lib.physcon.ru/doc?id=9e51935aa5bc

  4. Adaptive control of robotic manipulators

    Science.gov (United States)

    Seraji, H.

    1987-01-01

    The author presents a novel approach to adaptive control of manipulators to achieve trajectory tracking by the joint angles. The central concept in this approach is the utilization of the manipulator inverse as a feedforward controller. The desired trajectory is applied as an input to the feedforward controller which behaves as the inverse of the manipulator at any operating point; the controller output is used as the driving torque for the manipulator. The controller gains are then updated by an adaptation algorithm derived from MRAC (model reference adaptive control) theory to cope with variations in the manipulator inverse due to changes of the operating point. An adaptive feedback controller and an auxiliary signal are also used to enhance closed-loop stability and to achieve faster adaptation. The proposed control scheme is computationally fast and does not require a priori knowledge of the complex dynamic model or the parameter values of the manipulator or the payload.

  5. Robotic and automatic welding development at the Marshall Space Flight Center

    Science.gov (United States)

    Jones, C. S.; Jackson, M. E.; Flanigan, L. A.

    1988-01-01

    Welding automation is the key to two major development programs to improve quality and reduce the cost of manufacturing space hardware currently undertaken by the Materials and Processes Laboratory of the NASA Marshall Space Flight Center. Variable polarity plasma arc welding has demonstrated its effectiveness on class 1 aluminum welding in external tank production. More than three miles of welds were completed without an internal defect. Much of this success can be credited to automation developments which stabilize the process. Robotic manipulation technology is under development for automation of welds on the Space Shuttle's main engines utilizing pathfinder systems in development of tooling and sensors for the production applications. The overall approach to welding automation development undertaken is outlined. Advanced sensors and control systems methodologies are described that combine to make aerospace quality welds with a minimum of dependence on operator skill.

  6. Experience and Applications Up-date: Automation of Arc-Welding Operations Using Robot-Technology

    International Nuclear Information System (INIS)

    Teubel, G.

    1996-01-01

    In a short introduction, the important criteria for the correct choice of a robot cell, taking into account the given application, are highlighted. Furthermore, important hints are listed in terms of management decisions. The second chapter shows the main features of a welding robot cell in line with the present state of the art and describes some new developments with the aim of extending the arc-welding system to new applications such as flame cutting and beveling. The third chapter as centre piece gives an overall view of a brand new network control with many outstanding features for the users of arc-welding robots. the fourth and last chapter shows a recent realisation of a highly sophisticated F.M.S. system for welding, in random sequence, different large and heavy components. (Author) 1 ref

  7. On detection and automatic tracking of butt weld line in thin wall pipe welding by a mobile robot with visual sensor

    International Nuclear Information System (INIS)

    Suga, Yasuo; Ishii, Hideaki; Muto, Akifumi

    1992-01-01

    An automatic pipe welding mobile robot system with visual sensor was constructed. The robot can move along a pipe, and detect the weld line to be welded by visual sensor. Moreover, in order to make an automatic welding, the welding torch can track the butt weld line of the pipes at a constant speed by rotating the robot head. Main results obtained are summarized as follows: 1) Using a proper lighting fixed in front of the CCD camera, the butt weld line of thin wall pipes can be recongnized stably. In this case, the root gap should be approximately 0.5 mm. 2) In order to detect the weld line stably during moving along the pipe, a brightness distribution measured by the CCD camera should be subjected to smoothing and differentiating and then the weld line is judged by the maximum and minimum values of the differentials. 3) By means of the basic robot system with a visual sensor controlled by a personal computer, the detection and in-process automatic tracking of a weld line are possible. The average tracking error was approximately 0.2 mm and maximum error 0.5 mm and the welding speed was held at a constant value with error of about 0.1 cm/min. (author)

  8. Adaptive Robot Control – An Experimental Comparison

    Directory of Open Access Journals (Sweden)

    Francesco Alonge

    2012-11-01

    Full Text Available This paper deals with experimental comparison between stable adaptive controllers of robotic manipulators based on Model Based Adaptive, Neural Network and Wavelet -Based control. The above control methods were compared with each other in terms of computational efficiency, need for accurate mathematical model of the manipulator and tracking performances. An original management algorithm of the Wavelet Network control scheme has been designed, with the aim of constructing the net automatically during the trajectory tracking, without the need to tune it to the trajectory itself. Experimental tests, carried out on a planar two link manipulator, show that the Wavelet-Based control scheme, with the new management algorithm, outperforms the conventional Model-Based schemes in the presence of structural uncertainties in the mathematical model of the robot, without pre-training and more efficiently than the Neural Network approach.

  9. Adaptive Synchronization of Robotic Sensor Networks

    OpenAIRE

    Yıldırım, Kasım Sinan; Gürcan, Önder

    2014-01-01

    The main focus of recent time synchronization research is developing power-efficient synchronization methods that meet pre-defined accuracy requirements. However, an aspect that has been often overlooked is the high dynamics of the network topology due to the mobility of the nodes. Employing existing flooding-based and peer-to-peer synchronization methods, are networked robots still be able to adapt themselves and self-adjust their logical clocks under mobile network dynamics? In this paper, ...

  10. Evaluation of Distortion in Welding Unions of 304 Stainless Steel with Elliptic Trajectory Using a Welding Robot

    Science.gov (United States)

    Carrasco-González, L. A.; Hurtado-Delgado, E.; Reyes-Valdés, F. A.

    The aim of this investigation is to evaluate the distortions generated in welding unions of stainless steel 304 by effect of the welding temperature and the microestructural changes. The joint design is a 100 × 100 mm steel plate of 3 mm thickness. The plate was joined to a tube of 50 mm diameter and 2 mm thickness, which has a defined angular cut; therefore, the trajectory followed by the seam has an elliptic form. Temperature data acquisition was developed by type K thermocouples, placed in pairs at 0°, 90°, 180° and 270° along the welding trajectory and connected to a data acquisition device yo obtain the measures to generate time-temperature plots. The welding process was executed by a KUKA ®; KR16 welding robot with an integrated GMAW (Gas metal arc welding) process where the input parameters of voltage, wire feed and travel speed are set to constant. The distortion of the work piece was measured using a laser scanning technique that generates a point cloud with the VXelements TM software for comparison between the pre and post-weld condition. Microstructural evaluation was performed on transversal sections of the seam, at the mentioned angles for correlation.

  11. Sensor controlled robotic welding for nuclear power plant operations

    International Nuclear Information System (INIS)

    Chin, B.A.

    1989-01-01

    The objective of the proposed research is to apply real time monitoring, artificial intelligence and on-line correction to dynamically control the depth of weld penetration and weld integrity during the welding process. Welding is a major technique used in the fabrication, construction and maintenance of power generating and energy conversion systems. In the welding process, fluctuations in process variables lead to weld defects such as lack of penetration, cracks, porosity and undesirable metallurgical structures. This research will apply advanced infrared sensing techniques which have been successfully used in seam tracking to the equally complex problem of weld defect and weld puddle penetration control. Thermal temperature distributions of plates being welded will be dynamically measured during welding using infrared techniques. These temperature distributions will be used to interpret changes in the size and shape of the molten metal pool and the presence of conditions that may lead to defects in the solidified weld. The ultimate result of this research will be the development of machines which are capable of sensing and altering process variables to eliminate defective welds and increase the productivity of the welding process. Successful completion of this proposed research will lead to potential major improvements in the fabrication, construction and maintenance of advanced nuclear reactors and promote increased safety and reliability while decreasing construction costs. 47 refs., 50 figs

  12. Friction Stir Weld Application and Tooling Design for the Multi-purpose Crew Vehicle Stage Adapter

    Science.gov (United States)

    Alcorn, John

    2013-01-01

    The Multi-Purpose Crew Vehicle (MPCV), commonly known as the Orion capsule, is planned to be the United States' next manned spacecraft for missions beyond low earth orbit. Following the cancellation of the Constellation program and creation of SLS (Space Launch System), the need arose for the MPCV to utilize the Delta IV Heavy rocket for a test launch scheduled for 2014 instead of the previously planned Ares I rocket. As a result, an adapter (MSA) must be used in conjunction with the MPCV to account for the variation in diameter of the launch vehicles; 5.5 meters down to 5.0 meters. Prior to ight article fabrication, a path nder (test article) will be fabricated to ne tune the associated manufacturing processes. The adapter will be comprised of an aluminum frustum (partial cone) that employs isogrid technology and circumferential rings on each end. The frustum will be fabricated by friction stir welding (FSW) three individual panels together on a Vertical Weld Tool (VWT) at NASA Marshall Space Flight Center. Subsequently, each circumferential ring will be friction stir welded to the frustum using a Robotic Weld Tool (RWT). The irregular geometry and large mass of the MSA require that extensive tooling preparation be put into support structures for the friction stir weld. The tooling on the VWT will be comprised of a set of conveyors mounted on pre-existing stanchions so that the MSA will have the ability to be rotated after each of the three friction stir welds. The tooling requirements to friction stir weld the rings with the RWT are somewhat more demanding. To support the mass of the MSA and resist the load of the weld tool, a system of mandrels will be mounted to stanchions and assembled in a circle. The goal of the paper will be to explain the design, fabrication, and assembly of the tooling, to explain the use of friction stir welding on the MSA path nder, and also to discuss the lessons learned and modi cations made in preparation for ight article fabrication

  13. Robotic system for orbital welding of pipes; Sistema robotizado para soldagem orbital de dutos

    Energy Technology Data Exchange (ETDEWEB)

    Bracarense, Alexandre Queiroz; Lima, II, Eduardo Jose; Torres, Guilherme Fortunato; Ramalho, Frederico [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Felizardo, Ivanilza; Zanon, Gislaine Pires [ROTECH Tecnologia Robotica Ltda., Belo Horizonte, MG (Brazil)

    2004-07-01

    This work presents the robotic system projected for orbital welding of pipelines of oil and gas. The system consists of a controller (microcomputer), that allows the execution of all the referring tasks to the welding in an autonomous way, and two manipulates, to what are coupled the welding torches that are connected to a welding power source with double wire feeders. With this system, GMA W process is used to execute the root pass, while FCA W process, besides the GMA W, is used for the filling and finishing passes. The system has four degrees of freedom, allowing the control of stick out, travel speed, torch angle and positioning. Besides these, the arc voltage and and welding current are also controlled during the process. Knowing that for each welding position (plane, vertical up and down and over head) a great group of parameters must be used, several tests were accomplished. With these values a controlled variation could be accomplished in an uninterrupted way when welding position changes, getting the increase of the productivity and also the quality of the weld performed by a robotic system. (author)

  14. A development of an automated ultrasonic TOFD inspection system using an welding line tracing robot

    International Nuclear Information System (INIS)

    Cho, Hyun; Song, Sung Jin; Lee, Kang Won; Kim, Young Jin; Woo, Jong Sik

    2006-01-01

    Large scaled ships, manufactured inside of the country, should be passed welding inspection and painting film inspection. Normally, these kind of inspections are conducted by human inspectors manually, although it cause industrial disasters such as falling accidents and diving accidents frequently. In addition, Ship makers are not to give a full trust to shipowners because manual inspections cannot be conducted all over the welding parts. So, in this study we developed an automated ultrasonic TOFD inspection system using an welding line tracing robot. This system, controlled by an inspector at a remote field, can inspect welding parts of ship outer panel both under water and in air. In this paper we present the developed robot and ultrasonic TOFD inspection system and the inspection result.

  15. A development of an automated ultrasonic TOFD inspection system using an welding line tracing robot

    International Nuclear Information System (INIS)

    Cho, Hyun; Song, Sung Jin; Lee, Kang Won; Kim, Young Jin; Woo, Jong Sik

    2006-01-01

    Large scaled ships, manufactured inside of the country, should be passed welding inspection and painting film inspection. Normally, these kind of inspections are conducted by human inspectors manually, although it cause industrial disasters such as falling accidents and diving accidents frequently. In addition, Ship makers are not to give a full trust to ship owners because manual inspections cannot be conducted all over the welding parts. So, in this study we developed an automated ultrasonic TOFD inspection system using an welding line tracing robot. This system, controlled by an inspector at a remote field, can inspect welding parts of ship outer panel both under water and in air. In this paper we present the developed robot and ultrasonic TOFD inspection system and the inspection result.

  16. Study on robot motion control for intelligent welding processes based on the laser tracking sensor

    Science.gov (United States)

    Zhang, Bin; Wang, Qian; Tang, Chen; Wang, Ju

    2017-06-01

    A robot motion control method is presented for intelligent welding processes of complex spatial free-form curve seams based on the laser tracking sensor. First, calculate the tip position of the welding torch according to the velocity of the torch and the seam trajectory detected by the sensor. Then, search the optimal pose of the torch under constraints using genetic algorithms. As a result, the intersection point of the weld seam and the laser plane of the sensor is within the detectable range of the sensor. Meanwhile, the angle between the axis of the welding torch and the tangent of the weld seam meets the requirements. The feasibility of the control method is proved by simulation.

  17. Robotics

    Science.gov (United States)

    Popov, E. P.; Iurevich, E. I.

    The history and the current status of robotics are reviewed, as are the design, operation, and principal applications of industrial robots. Attention is given to programmable robots, robots with adaptive control and elements of artificial intelligence, and remotely controlled robots. The applications of robots discussed include mechanical engineering, cargo handling during transportation and storage, mining, and metallurgy. The future prospects of robotics are briefly outlined.

  18. Adaptive learning fuzzy control of a mobile robot

    International Nuclear Information System (INIS)

    Tsukada, Akira; Suzuki, Katsuo; Fujii, Yoshio; Shinohara, Yoshikuni

    1989-11-01

    In this report a problem is studied to construct a fuzzy controller for a mobile robot to move autonomously along a given reference direction curve, for which control rules are generated and acquired through an adaptive learning process. An adaptive learning fuzzy controller has been developed for a mobile robot. Good properties of the controller are shown through the travelling experiments of the mobile robot. (author)

  19. FUZZY REGRESSION MODEL TO PREDICT THE BEAD GEOMETRY IN THE ROBOTIC WELDING PROCESS

    Institute of Scientific and Technical Information of China (English)

    B.S. Sung; I.S. Kim; Y. Xue; H.H. Kim; Y.H. Cha

    2007-01-01

    Recently, there has been a rapid development in computer technology, which has in turn led todevelop the fully robotic welding system using artificial intelligence (AI) technology. However, therobotic welding system has not been achieved due to difficulties of the mathematical model andsensor technologies. The possibilities of the fuzzy regression method to predict the bead geometry,such as bead width, bead height, bead penetration and bead area in the robotic GMA (gas metalarc) welding process is presented. The approach, a well-known method to deal with the problemswith a high degree of fuzziness, is used to build the relationship between four process variablesand the four quality characteristics, respectively. Using these models, the proper prediction of theprocess variables for obtaining the optimal bead geometry can be determined.

  20. Strength analysis and optimization of welding robot mechanism in emergency stop state

    Directory of Open Access Journals (Sweden)

    Zdeněk Poruba

    2016-03-01

    Full Text Available The contribution deals with the strength analysis and optimization of the welding robot mechanism in emergency stop state. The common operational positioning of the welding robot is characterized by smooth course of speeds in the time. The resulting load does not differ significantly from the static loading. However the safety requirements given by the norm require the ability of emergency stop function. Since the course of speed in time is rather steep the higher values of acceleration and thus higher excitation force is expected. The dynamical simulation performed describes the response of the robot mechanism in the form of stress course in time, quantifies the peak values of the stress caused by the dynamical component of loading and highlights the potential risks associated with this phenomenon.

  1. Adaptive Robot to Person Encounter by Motion Patterns

    DEFF Research Database (Denmark)

    Andersen, Hans Jørgen; Bak, Thomas; Svenstrup, Mikael

    2009-01-01

    This paper introduces a new method for adaptive control of a robot approaching a person controlled by the person's interest in interaction. For adjustment of the robot behavior a cost function centered in the person is adapted according to an introduced person evaluator method relying on the three...... variables: the distance between the person and the robot, the relative velocity between the two, and position of the person. The person evaluator method determine the person's interest by evaluating the spatial relationship between robot and person in a Case Based Reasoning (CBR) system that is trained...... to determine to which degree the person is interested in interaction. The outcome of the CBR system is used to adapt the cost function around the person, so that the robot's behavior is adapted to the expressed interest. The proposed methods are evaluated by a number of physical experiments that demonstrate...

  2. Soft Ultrathin Electronics Innervated Adaptive Fully Soft Robots.

    Science.gov (United States)

    Wang, Chengjun; Sim, Kyoseung; Chen, Jin; Kim, Hojin; Rao, Zhoulyu; Li, Yuhang; Chen, Weiqiu; Song, Jizhou; Verduzco, Rafael; Yu, Cunjiang

    2018-03-01

    Soft robots outperform the conventional hard robots on significantly enhanced safety, adaptability, and complex motions. The development of fully soft robots, especially fully from smart soft materials to mimic soft animals, is still nascent. In addition, to date, existing soft robots cannot adapt themselves to the surrounding environment, i.e., sensing and adaptive motion or response, like animals. Here, compliant ultrathin sensing and actuating electronics innervated fully soft robots that can sense the environment and perform soft bodied crawling adaptively, mimicking an inchworm, are reported. The soft robots are constructed with actuators of open-mesh shaped ultrathin deformable heaters, sensors of single-crystal Si optoelectronic photodetectors, and thermally responsive artificial muscle of carbon-black-doped liquid-crystal elastomer (LCE-CB) nanocomposite. The results demonstrate that adaptive crawling locomotion can be realized through the conjugation of sensing and actuation, where the sensors sense the environment and actuators respond correspondingly to control the locomotion autonomously through regulating the deformation of LCE-CB bimorphs and the locomotion of the robots. The strategy of innervating soft sensing and actuating electronics with artificial muscles paves the way for the development of smart autonomous soft robots. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Dynamic modelling, identification and simulation of industrial robots – for off-line programming of robotised laser welding

    NARCIS (Netherlands)

    Waiboer, R.R.

    2007-01-01

    Robotised laser welding is an innovative joining technique which is increasingly finding applications, especially in the automotive industry. In order to reduce the time needed to prepare and programthe laser welding robot, off-line programming systems are used. The off-line programming systems

  4. Biologically-Inspired Adaptive Obstacle Negotiation Behavior of Hexapod Robots

    DEFF Research Database (Denmark)

    Goldschmidt, Dennis; Wörgötter, Florentin; Manoonpong, Poramate

    2014-01-01

    by these findings, we present an adaptive neural control mechanism for obstacle negotiation behavior in hexapod robots. It combines locomotion control, backbone joint control, local leg reflexes, and neural learning. While the first three components generate locomotion including walking and climbing, the neural...... learning mechanism allows the robot to adapt its behavior for obstacle negotiation with respect to changing conditions, e.g., variable obstacle heights and different walking gaits. By successfully learning the association of an early, predictive signal (conditioned stimulus, CS) and a late, reflex signal...... (unconditioned stimulus, UCS), both provided by ultrasonic sensors at the front of the robot, the robot can autonomously find an appropriate distance from an obstacle to initiate climbing. The adaptive neural control was developed and tested first on a physical robot simulation, and was then successfully...

  5. Evolutionary online behaviour learning and adaptation in real robots.

    Science.gov (United States)

    Silva, Fernando; Correia, Luís; Christensen, Anders Lyhne

    2017-07-01

    Online evolution of behavioural control on real robots is an open-ended approach to autonomous learning and adaptation: robots have the potential to automatically learn new tasks and to adapt to changes in environmental conditions, or to failures in sensors and/or actuators. However, studies have so far almost exclusively been carried out in simulation because evolution in real hardware has required several days or weeks to produce capable robots. In this article, we successfully evolve neural network-based controllers in real robotic hardware to solve two single-robot tasks and one collective robotics task. Controllers are evolved either from random solutions or from solutions pre-evolved in simulation. In all cases, capable solutions are found in a timely manner (1 h or less). Results show that more accurate simulations may lead to higher-performing controllers, and that completing the optimization process in real robots is meaningful, even if solutions found in simulation differ from solutions in reality. We furthermore demonstrate for the first time the adaptive capabilities of online evolution in real robotic hardware, including robots able to overcome faults injected in the motors of multiple units simultaneously, and to modify their behaviour in response to changes in the task requirements. We conclude by assessing the contribution of each algorithmic component on the performance of the underlying evolutionary algorithm.

  6. Biologically-Inspired Adaptive Obstacle Negotiation Behavior of Hexapod Robots

    Directory of Open Access Journals (Sweden)

    Dennis eGoldschmidt

    2014-01-01

    Full Text Available Neurobiological studies have shown that insects are able to adapt leg movements and posture for obstacle negotiation in changing environments. Moreover, the distance to an obstacle where an insect begins to climb is found to be a major parameter for successful obstacle negotiation. Inspired by these findings, we present an adaptive neural control mechanism for obstacle negotiation behavior in hexapod robots. It combines locomotion control, backbone joint control, local leg reflexes, and neural learning. While the first three components generate locomotion including walking and climbing, the neural learning mechanism allows the robot to adapt its behavior for obstacle negotiation with respect to changing conditions, e.g., variable obstacle heights and different walking gaits. By successfully learning the association of an early, predictive signal (conditioned stimulus, CS and a late, reflex signal (unconditioned stimulus, UCS, both provided by ultrasonic sensors at the front of the robot, the robot can autonomously find an appropriate distance from an obstacle to initiate climbing. The adaptive neural control was developed and tested first on a physical robot simulation, and was then successfully transferred to a real hexapod robot, called AMOS II. The results show that the robot can efficiently negotiate obstacles with a height up to 85% of the robot's leg length in simulation and 75% in a real environment.

  7. Design of parallel intersector weld/cut robot for machining processes in ITER vacuum vessel

    International Nuclear Information System (INIS)

    Wu Huapeng; Handroos, Heikki; Kovanen, Janne; Rouvinen, Asko; Hannukainen, Petri; Saira, Tanja; Jones, Lawrence

    2003-01-01

    This paper presents a new parallel robot Penta-WH, which has five degrees of freedom driven by hydraulic cylinders. The manipulator has a large, singularity-free workspace and high stiffness and it acts as a transport device for welding, machining and inspection end-effectors inside the ITER vacuum vessel. The presented kinematic structure of a parallel robot is particularly suitable for the ITER environment. Analysis of the machining process for ITER, such as the machining methods and forces are given, and the kinematic analyses, such as workspace and force capacity are discussed

  8. Robotics

    International Nuclear Information System (INIS)

    Scheide, A.W.

    1983-01-01

    This article reviews some of the technical areas and history associated with robotics, provides information relative to the formation of a Robotics Industry Committee within the Industry Applications Society (IAS), and describes how all activities relating to robotics will be coordinated within the IEEE. Industrial robots are being used for material handling, processes such as coating and arc welding, and some mechanical and electronics assembly. An industrial robot is defined as a programmable, multifunctional manipulator designed to move material, parts, tools, or specialized devices through variable programmed motions for a variety of tasks. The initial focus of the Robotics Industry Committee will be on the application of robotics systems to the various industries that are represented within the IAS

  9. Intelligent Modeling Combining Adaptive Neuro Fuzzy Inference System and Genetic Algorithm for Optimizing Welding Process Parameters

    Science.gov (United States)

    Gowtham, K. N.; Vasudevan, M.; Maduraimuthu, V.; Jayakumar, T.

    2011-04-01

    Modified 9Cr-1Mo ferritic steel is used as a structural material for steam generator components of power plants. Generally, tungsten inert gas (TIG) welding is preferred for welding of these steels in which the depth of penetration achievable during autogenous welding is limited. Therefore, activated flux TIG (A-TIG) welding, a novel welding technique, has been developed in-house to increase the depth of penetration. In modified 9Cr-1Mo steel joints produced by the A-TIG welding process, weld bead width, depth of penetration, and heat-affected zone (HAZ) width play an important role in determining the mechanical properties as well as the performance of the weld joints during service. To obtain the desired weld bead geometry and HAZ width, it becomes important to set the welding process parameters. In this work, adaptative neuro fuzzy inference system is used to develop independent models correlating the welding process parameters like current, voltage, and torch speed with weld bead shape parameters like depth of penetration, bead width, and HAZ width. Then a genetic algorithm is employed to determine the optimum A-TIG welding process parameters to obtain the desired weld bead shape parameters and HAZ width.

  10. Problem of quality assurance during metal constructions welding via robotic technological complexes

    Science.gov (United States)

    Fominykh, D. S.; Rezchikov, A. F.; Kushnikov, V. A.; Ivashchenko, V. A.; Bogomolov, A. S.; Filimonyuk, L. Yu; Dolinina, O. N.; Kushnikov, O. V.; Shulga, T. E.; Tverdokhlebov, V. A.

    2018-05-01

    The problem of minimizing the probability for critical combinations of events that lead to a loss in welding quality via robotic process automation is examined. The problem is formulated, models and algorithms for its solution are developed. The problem is solved by minimizing the criterion characterizing the losses caused by defective products. Solving the problem may enhance the quality and accuracy of operations performed and reduce the losses caused by defective product

  11. Challenges in adapting imitation and reinforcement learning to compliant robots

    Directory of Open Access Journals (Sweden)

    Calinon Sylvain

    2011-12-01

    Full Text Available There is an exponential increase of the range of tasks that robots are forecasted to accomplish. (Reprogramming these robots becomes a critical issue for their commercialization and for their applications to real-world scenarios in which users without expertise in robotics wish to adapt the robot to their needs. This paper addresses the problem of designing userfriendly human-robot interfaces to transfer skills in a fast and efficient manner. This paper presents recent work conducted at the Learning and Interaction group at ADVR-IIT, ranging from skill acquisition through kinesthetic teaching to self-refinement strategies initiated from demonstrations. Our group started to explore the use of imitation and exploration strategies that can take advantage of the compliant capabilities of recent robot hardware and control architectures.

  12. Welding mechanization in shipyard CIM; Zosen ni okeru yosetsu no jidoka robot ka CIM ka

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, T. [Hitachi Zosen Corp., Osaka (Japan)

    1997-12-01

    This paper explains development and examples of application of automated welding devices from a viewpoint of an element technology constituting computer integrated manufacturing (CIM), based on the history of modernization of shipyards that has been achieved to date. In the first step of promoting the modernization, elevating cutting accuracy in the uppermost stream process was thought a starting point of rationalization. What have been achieved therefrom are adoption of the most advanced NC plasma cutting machine, and improvement in the computer aided system for the cutting machines. In addition, a twenty-electrode line welder has been developed, which does not create angle deformation in welding longerons, and can be operated even by unskilled workers. The welder has successfully realized a construction method in which robots can be applied more easily. Further developments have been made on a robot to weld cells, advanced CAD/CAM operation techniques which are linked with data from design, an automatic one-side welding device which can achieve a speed 2.5 times greater than by conventional devices, and an automation device for three-dimensionally bent blocks, whose automation has been regarded difficult. 11 figs., 1 tab.

  13. Design of the Intersector Welding Robot for vacuum vessel assembly and maintenance

    International Nuclear Information System (INIS)

    Jones, L.; Dagenais, J.-F.; Daenner, W.; Maisonnier, D.

    2000-01-01

    Next Step Fusion Devices require on-site (field weld) joining of sectors of the thick-walled vacuum vessel for structural and vacuum integrity. EFDA (European Fusion Development Agreement) is supporting an R and D programme to investigate processes for assembly of the vacuum vessel and to carry out cutting, re-welding and inspection for remote sector replacement, forming part of the overall VV/blanket research effort. In order to direct the process end-effectors along the field joint zone, a track-mounted Intersector Welding Robot (IWR) on a mock-up of a region of the vacuum vessel has been designed and is described in this paper. A rail-mounted hexapod type robot offers six axes of motion over a limited work envelope with high payload to robot weight ratio. A solution to the production of reduced pressure local vacuum is the installation of short, lightweight segments bolted to each other and the vessel wall. The various process heads can be mounted using end-effectors of special design. To minimise the supply and interface problems for the IWR prototype, its motion control and electronic systems will be embedded locally. A laser scan with camera forms the on-line seam tracking capability to compensate for rail and seam deviations

  14. An adaptive inverse kinematics algorithm for robot manipulators

    Science.gov (United States)

    Colbaugh, R.; Glass, K.; Seraji, H.

    1990-01-01

    An adaptive algorithm for solving the inverse kinematics problem for robot manipulators is presented. The algorithm is derived using model reference adaptive control (MRAC) theory and is computationally efficient for online applications. The scheme requires no a priori knowledge of the kinematics of the robot if Cartesian end-effector sensing is available, and it requires knowledge of only the forward kinematics if joint position sensing is used. Computer simulation results are given for the redundant seven-DOF robotics research arm, demonstrating that the proposed algorithm yields accurate joint angle trajectories for a given end-effector position/orientation trajectory.

  15. Video Game Device Haptic Interface for Robotic Arc Welding

    Energy Technology Data Exchange (ETDEWEB)

    Corrie I. Nichol; Milos Manic

    2009-05-01

    Recent advances in technology for video games have made a broad array of haptic feedback devices available at low cost. This paper presents a bi-manual haptic system to enable an operator to weld remotely using the a commercially available haptic feedback video game device for the user interface. The system showed good performance in initial tests, demonstrating the utility of low cost input devices for remote haptic operations.

  16. Pose Estimation and Adaptive Robot Behaviour for Human-Robot Interaction

    DEFF Research Database (Denmark)

    Svenstrup, Mikael; Hansen, Søren Tranberg; Andersen, Hans Jørgen

    2009-01-01

    Abstract—This paper introduces a new method to determine a person’s pose based on laser range measurements. Such estimates are typically a prerequisite for any human-aware robot navigation, which is the basis for effective and timeextended interaction between a mobile robot and a human. The robot......’s pose. The resulting pose estimates are used to identify humans who wish to be approached and interacted with. The interaction motion of the robot is based on adaptive potential functions centered around the person that respect the persons social spaces. The method is tested in experiments...

  17. Coating application procedure qualification for internal girth weld using a robot device

    Energy Technology Data Exchange (ETDEWEB)

    Koebsch, Andre; Cunha, Bruno Rocha Marques da; Barreto, Eduardo Chave; Nunes, Erik Barbosa; Solymossy, Victor [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2009-12-19

    This year PETROBRAS complete 55 years old filling up our country of energy necessary to support our development. Some oil fields, especially from the northeast region, has being had their production decrease by their ageing. In order to have their live protracted some retrieval technical has being used. For example we can mention gas lift, production water injection, CO{sub 2} injection and so on. The produced water even treated has an elevated tenor of chloride, acid ph, presence of organics acids, H{sub 2}S and no O{sub 2}. The water became too corrosive by those characteristics. Due to it an anti corrosive coating application is demanded on the pipe internal surface and on the girth weld. The pipes are coated in a coating plant and it has a qualified coating procedure. Therefore an application of anti corrosive coating is demanded on the girth weld after the pipe welding. To accomplish this job an application procedure was developed using a robot. The PETROBRAS' Engineer witnesses the PQT of this procedure aiming to guarantee the applied coating quality. This paper will show the PQT results and a basic description of the robot operation. (author)

  18. Direct adaptive control of a PUMA 560 industrial robot

    Science.gov (United States)

    Seraji, Homayoun; Lee, Thomas; Delpech, Michel

    1989-01-01

    The implementation and experimental validation of a new direct adaptive control scheme on a PUMA 560 industrial robot is described. The testbed facility consists of a Unimation PUMA 560 six-jointed robot and controller, and a DEC MicroVAX II computer which hosts the Robot Control C Library software. The control algorithm is implemented on the MicroVAX which acts as a digital controller for the PUMA robot, and the Unimation controller is effectively bypassed and used merely as an I/O device to interface the MicroVAX to the joint motors. The control algorithm for each robot joint consists of an auxiliary signal generated by a constant-gain Proportional plus Integral plus Derivative (PID) controller, and an adaptive position-velocity (PD) feedback controller with adjustable gains. The adaptive independent joint controllers compensate for the inter-joint couplings and achieve accurate trajectory tracking without the need for the complex dynamic model and parameter values of the robot. Extensive experimental results on PUMA joint control are presented to confirm the feasibility of the proposed scheme, in spite of strong interactions between joint motions. Experimental results validate the capabilities of the proposed control scheme. The control scheme is extremely simple and computationally very fast for concurrent processing with high sampling rates.

  19. Novel Robot Solutions for Carrying out Field Joint Welding and Machining in the Assembly of the Vacuum Vessel of ITER

    International Nuclear Information System (INIS)

    Pessi, P.

    2009-01-01

    It is necessary to use highly specialized robots in ITER (International Thermonuclear Experimental Reactor) both in the manufacturing and maintenance of the reactor due to a demanding environment. The sectors of the ITER vacuum vessel (VV) require more stringent tolerances than normally expected for the size of the structure involved. VV consists of nine sectors that are to be welded together. The vacuum vessel has a toroidal chamber structure. The task of the designed robot is to carry the welding apparatus along a path with a stringent tolerance during the assembly operation. In addition to the initial vacuum vessel assembly, after a limited running period, sectors need to be replaced for repair. Mechanisms with closed-loop kinematic chains are used in the design of robots in this work. One version is a purely parallel manipulator and another is a hybrid manipulator where the parallel and serial structures are combined. Traditional industrial robots that generally have the links actuated in series are inherently not very rigid and have poor dynamic performance in high speed and high dynamic loading conditions. Compared with open chain manipulators, parallel manipulators have high stiffness, high accuracy and a high force/torque capacity in a reduced workspace. Parallel manipulators have a mechanical architecture where all of the links are connected to the base and to the end-effector of the robot. The purpose of this thesis is to develop special parallel robots for the assembly, machining and repairing of the VV of the ITER. The process of the assembly and machining of the vacuum vessel needs a special robot. By studying the structure of the vacuum vessel, two novel parallel robots were designed and built; they have six and ten degrees of freedom driven by hydraulic cylinders and electrical servo motors. Kinematic models for the proposed robots were defined and two prototypes built. Experiments for machine cutting and laser welding with the 6-DOF robot were

  20. Novel Robot Solutions for Carrying out Field Joint Welding and Machining in the Assembly of the Vacuum Vessel of ITER

    Energy Technology Data Exchange (ETDEWEB)

    Pessi, P.

    2009-07-01

    It is necessary to use highly specialized robots in ITER (International Thermonuclear Experimental Reactor) both in the manufacturing and maintenance of the reactor due to a demanding environment. The sectors of the ITER vacuum vessel (VV) require more stringent tolerances than normally expected for the size of the structure involved. VV consists of nine sectors that are to be welded together. The vacuum vessel has a toroidal chamber structure. The task of the designed robot is to carry the welding apparatus along a path with a stringent tolerance during the assembly operation. In addition to the initial vacuum vessel assembly, after a limited running period, sectors need to be replaced for repair. Mechanisms with closed-loop kinematic chains are used in the design of robots in this work. One version is a purely parallel manipulator and another is a hybrid manipulator where the parallel and serial structures are combined. Traditional industrial robots that generally have the links actuated in series are inherently not very rigid and have poor dynamic performance in high speed and high dynamic loading conditions. Compared with open chain manipulators, parallel manipulators have high stiffness, high accuracy and a high force/torque capacity in a reduced workspace. Parallel manipulators have a mechanical architecture where all of the links are connected to the base and to the end-effector of the robot. The purpose of this thesis is to develop special parallel robots for the assembly, machining and repairing of the VV of the ITER. The process of the assembly and machining of the vacuum vessel needs a special robot. By studying the structure of the vacuum vessel, two novel parallel robots were designed and built; they have six and ten degrees of freedom driven by hydraulic cylinders and electrical servo motors. Kinematic models for the proposed robots were defined and two prototypes built. Experiments for machine cutting and laser welding with the 6-DOF robot were

  1. Robot vision

    International Nuclear Information System (INIS)

    Hall, E.L.

    1984-01-01

    Almost all industrial robots use internal sensors such as shaft encoders which measure rotary position, or tachometers which measure velocity, to control their motions. Most controllers also provide interface capabilities so that signals from conveyors, machine tools, and the robot itself may be used to accomplish a task. However, advanced external sensors, such as visual sensors, can provide a much greater degree of adaptability for robot control as well as add automatic inspection capabilities to the industrial robot. Visual and other sensors are now being used in fundamental operations such as material processing with immediate inspection, material handling with adaption, arc welding, and complex assembly tasks. A new industry of robot vision has emerged. The application of these systems is an area of great potential

  2. Minimum Time Path Planning for Robotic Manipulator in Drilling/ Spot Welding Tasks

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2016-04-01

    Full Text Available In this paper, a minimum time path planning strategy is proposed for multi points manufacturing problems in drilling/spot welding tasks. By optimizing the travelling schedule of the set points and the detailed transfer path between points, the minimum time manufacturing task is realized under fully utilizing the dynamic performance of robotic manipulator. According to the start-stop movement in drilling/spot welding task, the path planning problem can be converted into a traveling salesman problem (TSP and a series of point to point minimum time transfer path planning problems. Cubic Hermite interpolation polynomial is used to parameterize the transfer path and then the path parameters are optimized to obtain minimum point to point transfer time. A new TSP with minimum time index is constructed by using point-point transfer time as the TSP parameter. The classical genetic algorithm (GA is applied to obtain the optimal travelling schedule. Several minimum time drilling tasks of a 3-DOF robotic manipulator are used as examples to demonstrate the effectiveness of the proposed approach.

  3. Hand-Eye LRF-Based Iterative Plane Detection Method for Autonomous Robotic Welding

    Directory of Open Access Journals (Sweden)

    Sungmin Lee

    2015-12-01

    Full Text Available This paper proposes a hand-eye LRF-based (laser range finder welding plane-detection method for autonomous robotic welding in the field of shipbuilding. The hand-eye LRF system consists of a 6 DOF manipulator and an LRF attached to the wrist of the manipulator. The welding plane is detected by the LRF with only the wrist's rotation to minimize a mechanical error caused by the manipulator's motion. A position on the plane is determined as an average position of the detected points on the plane, and a normal vector to the plane is determined by applying PCA (principal component analysis to the detected points. In this case, the accuracy of the detected plane is analysed by simulations with respect to the wrist's angle interval and the plane angle. As a result of the analysis, an iterative plane-detection method with the manipulator's alignment motion is proposed to improve the performance of plane detection. For verifying the feasibility and effectiveness of the proposed plane-detection method, experiments are carried out with a prototype of the hand-eye LRF-based system, which consists of a 1 DOF wrist's joint, an LRF system and a rotatable plane. In addition, the experimental results of the PCA-based plane detection method are compared with those of the two representative plane-detection methods, based on RANSAC (RANdom SAmple Consensus and the 3D Hough transform in both accuracy and computation time's points of view.

  4. Development and control towards a parallel water hydraulic weld/cut robot for machining processes in ITER vacuum vessel

    International Nuclear Information System (INIS)

    Wu Huapeng; Handroos, Heikki; Pessi, Pekka; Kilkki, Juha; Jones, Lawrence

    2005-01-01

    This paper presents a special robot, able to carry out welding and machining processes from inside the ITER vacuum vessel (VV), consisting of a five degree-of-freedom parallel mechanism, mounted on a carriage driven by two electric motors on a rack. The kinematic design of the robot has been optimised for ITER access and a hydraulically actuated pre-prototype built. A hybrid controller is designed for the robot, including position, speed and pressure feedback loops to achieve high accuracy and high dynamic performances. Finally, the experimental tests are given and discussed

  5. A discrete-time adaptive control scheme for robot manipulators

    Science.gov (United States)

    Tarokh, M.

    1990-01-01

    A discrete-time model reference adaptive control scheme is developed for trajectory tracking of robot manipulators. The scheme utilizes feedback, feedforward, and auxiliary signals, obtained from joint angle measurement through simple expressions. Hyperstability theory is utilized to derive the adaptation laws for the controller gain matrices. It is shown that trajectory tracking is achieved despite gross robot parameter variation and uncertainties. The method offers considerable design flexibility and enables the designer to improve the performance of the control system by adjusting free design parameters. The discrete-time adaptation algorithm is extremely simple and is therefore suitable for real-time implementation. Simulations and experimental results are given to demonstrate the performance of the scheme.

  6. Combining Environment-Driven Adaptation and Task-Driven Optimisation in Evolutionary Robotics

    NARCIS (Netherlands)

    Haasdijk, E.W.; Bredeche, Nicolas; Eiben, A.E.

    2014-01-01

    Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-)adjusting

  7. ADAPTIVE DISTRIBUTION OF A SWARM OF HETEROGENEOUS ROBOTS

    Directory of Open Access Journals (Sweden)

    Amanda Prorok

    2016-02-01

    Full Text Available We present a method that distributes a swarm of heterogeneous robots among a set of tasks that require specialized capabilities in order to be completed. We model the system of heterogeneous robots as a community of species, where each species (robot type is defined by the traits (capabilities that it owns. Our method is based on a continuous abstraction of the swarm at a macroscopic level as we model robots switching between tasks. We formulate an optimization problem that produces an optimal set of transition rates for each species, so that the desired trait distribution is reached as quickly as possible. Since our method is based on the derivation of an analytical gradient, it is very efficient with respect to state-of-the-art methods. Building on this result, we propose a real-time optimization method that enables an online adaptation of transition rates. Our approach is well-suited for real-time applications that rely on online redistribution of large-scale robotic systems.

  8. First industrial application of MAG STT welding with auto adaptative joint control

    International Nuclear Information System (INIS)

    Tran Tien, Thong

    2006-01-01

    The Welding Institute has participated to an extraordinary plan: the manufacture of the new LHC (Large Hadron Collider) particles accelerator in a circular tunnel of 27 km of circumference, at the European laboratory for particles physics (CERN) located at the Franco-Swiss frontier. The LHC dipolar magnets wires constituted in semi-cylinders of 15 m length in 316 LN, thickness 10 mm, are assembled in horizontal-vertical position. The Welding Institute has developed a software allowing to implement the auto-adaptative welding with follow of laser joint, using the MAG STT (Surface Tension Transfer) process. The modeling of welding laws connected with the strategy of joints filling runs (in multi-passes), absorb the physical tolerances of the preparation (clearance, poor alignment, root of joint...) and this in welding dynamical condition. (O.M.)

  9. First industrial application of the auto-adaptative MAG STT welding technique with laser joint tracking

    International Nuclear Information System (INIS)

    Tran Tien, Th.

    2007-01-01

    The Welding Institute has participated to the plan of construction of the Large Hadron Collider. The hoops of the dipolar magnets are composed of two half cylinders 15 m in length in 10 mm 316LN austenitic stainless steel and are assembled around the magnet in a horizontal-vertical position. The Welding Institute has developed a software for carrying out the auto-adaptative welding technique with laser joint tracking, in using the MAG STT (Surface Tension Transfer) process. The modelling of the welding laws and the strategy of filling the joints in multi-paths absorb the physical tolerances of the preparation (clearance, poor alignment, root..) in dynamic welding condition too. (O.M.)

  10. Adaptation of the IBM ECR [electric cantilever robot] robot to plutonium processing applications

    International Nuclear Information System (INIS)

    Armantrout, G.A.; Pedrotti, L.R.; Halter, E.A.; Crossfield, M.

    1990-12-01

    The changing regulatory climate in the US is adding increasing incentive to reduce operator dose and TRU waste for DOE plutonium processing operations. To help achieve that goal the authors have begun adapting a small commercial overhead gantry robot, the IBM electric cantilever robot (ECR), to plutonium processing applications. Steps are being taken to harden this robot to withstand the dry, often abrasive, environment within a plutonium glove box and to protect the electronic components against alpha radiation. A mock-up processing system for the reduction of the oxide to a metal was prepared and successfully demonstrated. Design of a working prototype is now underway using the results of this mock-up study. 7 figs., 4 tabs

  11. The Dynamics and Sliding Mode Control of Multiple Cooperative Welding Robot Manipulators

    Directory of Open Access Journals (Sweden)

    Bin Zi

    2012-08-01

    Full Text Available This paper deals with the design, dynamic modelling and sliding mode control of multiple cooperative welding robot manipulators (MWRMs. The MWRMs can handle complex tasks that are difficult or even impossible for a single manipulator. The kinematics and dynamics of the MWRMs are studied on the basis of the Denavit-Hartenberg and Lagrange method. Following that, considering the MWRM system with nonlinear and unknown disturbances, a non-singular terminal sliding mode control strategy is designed. By means of the Lyapunov function, the stability of the controller is proved. Simulation results indicate that the good control performance of the MWRMs is achieved by the non-singular terminal sliding mode controller, which also illustrates the correctness of the dynamic modelling and effectiveness of the proposed control strategy.

  12. Adaptive Robotic Systems Design in University of Applied Sciences

    Directory of Open Access Journals (Sweden)

    Gunsing Jos

    2016-01-01

    Full Text Available In the industry for highly specialized machine building (small series with high variety and high complexity and in healthcare a demand for adaptive robotics is rapidly coming up. Technically skilled people are not always available in sufficient numbers. A lot of know how with respect to the required technologies is available but successful adaptive robotic system designs are still rare. In our research at the university of applied sciences we incorporate new available technologies in our education courses by way of research projects; in these projects students will investigate the application possibilities of new technologies together with companies and teachers. Thus we are able to transfer knowledge to the students including an innovation oriented attitude and skills. Last years we developed several industrial binpicking applications for logistics and machining-factories with different types of 3D vision. Also force feedback gripping has been developed including slip sensing. Especially for healthcare robotics we developed a so-called twisted wire actuator, which is very compact in combination with an underactuated gripper, manufactured in one piece in polyurethane. We work both on modeling and testing the functions of these designs but we work also on complete demonstrator systems. Since the amount of disciplines involved in complex product and machine design increases rapidly we pay a lot of attention with respect to systems engineering methods. Apart from the classical engineering disciplines like mechanical, electrical, software and mechatronics engineering, especially for adaptive robotics more and more disciplines like industrial product design, communication … multimedia design and of course physics and even art are to be involved depending on the specific application to be designed. Design tools like V-model, agile/scrum and design-approaches to obtain the best set of requirements are being implemented in the engineering studies from

  13. An adaptable Boolean net trainable to control a computing robot

    International Nuclear Information System (INIS)

    Lauria, F. E.; Prevete, R.; Milo, M.; Visco, S.

    1999-01-01

    We discuss a method to implement in a Boolean neural network a Hebbian rule so to obtain an adaptable universal control system. We start by presenting both the Boolean neural net and the Hebbian rule we have considered. Then we discuss, first, the problems arising when the latter is naively implemented in a Boolean neural net, second, the method consenting us to overcome them and the ensuing adaptable Boolean neural net paradigm. Next, we present the adaptable Boolean neural net as an intelligent control system, actually controlling a writing robot, and discuss how to train it in the execution of the elementary arithmetic operations on operands represented by numerals with an arbitrary number of digits

  14. Development of a robotic manipulator for orbital welding; Desenvolvimento de um manipulador robotico para a sondagem orbital

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Renon Steinbach; Dutra, Jair Carlos [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Lab. de Soldagem; Bonacorso, Nelso Gauze [Centro Federal de Educacao Tecnologica de Santa Catarina (CEFET/SC), Florianopolis, SC (Brazil). Lab. da Automacao Hidraulica e Pneumatica (LAHP)

    2008-07-01

    On the national oil scenario, the pipelines have a high cost, specially on the long time spent on its constructions. Thus, this transaction optimizations become highly attractive. A form of improvement this task is to automate the process of welding. In this context it is interesting the use of a robot manipulator for the orbital welding. In the international market, there are dedicates solutions that meet the restrictions associated mainly with the ease of handling and dimensions. However,since these manipulators use foreign technology this makes the acquisition and maintenance costs high. The project aims to create subsides for greater efficiency in the task of union of pipelines through the development of a robotic manipulator. However it is clear that only the design of such a handler does not guarantee the quality of the root pass. Therefore, it is also being studied the use of the process MIG (Metal Inert Gas), through parametrization of CCC (Short-circuit controlled) in order to have a robust process of welding. The CCC monitors the process of welding and acts when there is detection od short circuit. It is obtained then higher pass from scratch controllability and drastically reduces the amount of spay. (author)

  15. People-Centered Development of a Smart Learning Ecosystem of Adaptive Robots

    DEFF Research Database (Denmark)

    Fischer, Daniel Kjær Bonde; Kristiansen, Jakob; Mariager, Casper

    2019-01-01

    Robots are currently moving out of the laboratory and company floor into more human and social contexts including care, rehabilitation and education. While those robots are usually envisioned as a kind of social interaction partner, we suggest a different approach, where robots become adaptive...

  16. Adaptive Robotic Fabrication for Conditions of Material Inconsistency

    DEFF Research Database (Denmark)

    Nicholas, Paul; Zwierzycki, Mateusz; Clausen Nørgaard, Esben

    2017-01-01

    This paper describes research that addresses the variable behaviour of industrial quality metals and the extension of computational techniques into the fabrication process. It describes the context of robotic incremental sheet metal forming, a freeform method for imparting 3D form onto a 2D thin...... and the fabrication process? Here, two adaptive methods are presented that aim to increase forming accuracy with only a minimum increase in fabrication time, and that maintain ongoing input from the results of the fabrication process. The first method is an online sensor-based strategy and the second method...

  17. Beyond adaptive-critic creative learning for intelligent mobile robots

    Science.gov (United States)

    Liao, Xiaoqun; Cao, Ming; Hall, Ernest L.

    2001-10-01

    Intelligent industrial and mobile robots may be considered proven technology in structured environments. Teach programming and supervised learning methods permit solutions to a variety of applications. However, we believe that to extend the operation of these machines to more unstructured environments requires a new learning method. Both unsupervised learning and reinforcement learning are potential candidates for these new tasks. The adaptive critic method has been shown to provide useful approximations or even optimal control policies to non-linear systems. The purpose of this paper is to explore the use of new learning methods that goes beyond the adaptive critic method for unstructured environments. The adaptive critic is a form of reinforcement learning. A critic element provides only high level grading corrections to a cognition module that controls the action module. In the proposed system the critic's grades are modeled and forecasted, so that an anticipated set of sub-grades are available to the cognition model. The forecasting grades are interpolated and are available on the time scale needed by the action model. The success of the system is highly dependent on the accuracy of the forecasted grades and adaptability of the action module. Examples from the guidance of a mobile robot are provided to illustrate the method for simple line following and for the more complex navigation and control in an unstructured environment. The theory presented that is beyond the adaptive critic may be called creative theory. Creative theory is a form of learning that models the highest level of human learning - imagination. The application of the creative theory appears to not only be to mobile robots but also to many other forms of human endeavor such as educational learning and business forecasting. Reinforcement learning such as the adaptive critic may be applied to known problems to aid in the discovery of their solutions. The significance of creative theory is that it

  18. Feedback control of laser welding based on frequency analysis of light emissions and adaptive beam shaping

    Czech Academy of Sciences Publication Activity Database

    Mrňa, Libor; Šarbort, Martin; Řeřucha, Šimon; Jedlička, Petr

    2012-01-01

    Roč. 39, NOV (2012), s. 784-791 ISSN 1875-3892. [LANE 2012. Laser Assisted Net Shape Engineering /7./ International Conference on Photonic Technologies. Fürth, 12.11.2012-15.12.2012] Institutional support: RVO:68081731 Keywords : laser welding * feedback control * frequency analysis * adaptive beam shaping Subject RIV: BH - Optics, Masers, Lasers

  19. Enhancing the Ductility of Laser-Welded Copper-Aluminum Connections by using Adapted Filler Materials

    Science.gov (United States)

    Weigl, M.; Albert, F.; Schmidt, M.

    Laser micro welding of direct copper-aluminum connections typically leads to the formation of intermetallic phases and an embrittlement of the metal joints. By means of adapted filler materials it is possible to reduce the brittle phases and thereby enhance the ductility of these dissimilar connections. As the element silicon features quite a well compatibility with copper and aluminum, filler materials based on Al-Si and Cu-Si alloys are used in the current research studies. In contrast to direct Cu-Al welds, the aluminum filler alloy AlSi12 effectuates a more uniform element mixture and a significantly enhanced ductility.

  20. Welding.

    Science.gov (United States)

    Cowan, Earl; And Others

    The curriculum guide for welding instruction contains 16 units presented in six sections. Each unit is divided into the following areas, each of which is color coded: terminal objectives, specific objectives, suggested activities, and instructional materials; information sheet; transparency masters; assignment sheet; test; and test answers. The…

  1. The National Shipbuilding Research Program: Evaluation of the Cincinnati Milacron T-3 Robot for Shipbuilding Welding

    Science.gov (United States)

    1984-01-01

    acknowledgement is extended to the members of Welding Panel SP-7 of the SNAME Ship Production Committee, who served as technical advisors in the preparation...Binzel Robo 450. . . . . . 4.4.4.1.3 Hobart WCG 600 . . . . . . 4.4.4.2 Maintenance and Service . . . . . . . 4.4.4.3 Recommendation...Machine Specialties D & F - Welding . . . Torch Binzel Robo 450 - Welding Torch. Hobart WCG - 600 - Welding Torch. Binzel Nozzle Cleaner

  2. Adaptive particle filter for localization problem in service robotics

    Directory of Open Access Journals (Sweden)

    Heilig Alexander

    2018-01-01

    Full Text Available In this paper we present a statistical approach to the likelihood computation and adaptive resampling algorithm for particle filters using low cost ultrasonic sensors in the context of service robotics. This increases the efficiency of the particle filter in the Monte Carlo Localization problem by means of preventing sample impoverishment and ensuring it converges towards the most likely particle and simultaneously keeping less likely ones by systematic resampling. Proposed algorithms were developed in the ROS framework, simulation was done in Gazebo environment. Experiments using a differential drive mobile platform with 4 ultrasonic sensors in the office environment show that our approach provides strong improvement over particle filters with fixed sample sizes.

  3. Mathematical model for adaptive control system of ASEA robot at Kennedy Space Center

    Science.gov (United States)

    Zia, Omar

    1989-01-01

    The dynamic properties and the mathematical model for the adaptive control of the robotic system presently under investigation at Robotic Application and Development Laboratory at Kennedy Space Center are discussed. NASA is currently investigating the use of robotic manipulators for mating and demating of fuel lines to the Space Shuttle Vehicle prior to launch. The Robotic system used as a testbed for this purpose is an ASEA IRB-90 industrial robot with adaptive control capabilities. The system was tested and it's performance with respect to stability was improved by using an analogue force controller. The objective of this research project is to determine the mathematical model of the system operating under force feedback control with varying dynamic internal perturbation in order to provide continuous stable operation under variable load conditions. A series of lumped parameter models are developed. The models include some effects of robot structural dynamics, sensor compliance, and workpiece dynamics.

  4. L-ALLIANCE: a mechanism for adaptive action selection in heterogeneous multi-robot teams

    Energy Technology Data Exchange (ETDEWEB)

    Parker, L.E.

    1995-11-01

    In practical applications of robotics, it is usually quite difficult, if not impossible, for the system designer to fully predict the environmental states in which the robots will operate. The complexity of the problem is further increased when dealing with teams of robots which themselves may be incompletely known and characterized in advance. It is thus highly desirable for robot teams to be able to adapt their performance during the mission due to changes in the environment, or to changes in other robot team members. In previous work, we introduced a behavior-based mechanism called the ALLIANCE architecture -- that facilitates the fault tolerant cooperative control of multi-robot teams. However, this previous work did not address the issue of how to dynamically update the control parameters during a mission to adapt to ongoing changes in the environment or in the robot team, and to ensure the efficiency of the collective team actions. In this paper, we address this issue by proposing the L-ALLIANCE mechanism, which defines an automated method whereby robots can use knowledge learned from previous experience to continually improve their collective action selection when working on missions composed of loosely coupled, discrete subtasks. This ability to dynamically update robotic control parameters provides a number of distinct advantages: it alleviates the need for human tuning of control parameters, it facilitates the use of custom-designed multi-robot teams for any given application, it improves the efficiency of the mission performance, and It allows robots to continually adapt their performance over time due to changes in the robot team and/or the environment. We describe the L-ALLIANCE mechanism, present the results of various alternative update strategies we investigated, present the formal model of the L-ALLIANCE mechanism, and present the results of a simple proof of concept implementation on a small team of heterogeneous mobile robots.

  5. An Adaptive Approach for Precise Underwater Vehicle Control in Combined Robot-Diver Operations

    Science.gov (United States)

    2015-03-01

    and Nicosia and Tomei [13] focused on industrial applications involving robotic manipulator arms carrying various loads. The application of...1987. 94 [13] S. Nicosia and P. Tomei, “Model reference adaptive control algorithms for industrial robots ,” Automatica, vol. 20, pp. 635–644, 9... kinematic and dynamic properties,” The International Journal of Robotics Research, vol. 25, pp. 283–296, March 01, 2006. [17] A. Sanei and M. French

  6. An Exploratory Investigation into the Effects of Adaptation in Child-Robot Interaction

    Science.gov (United States)

    Salter, Tamie; Michaud, François; Létourneau, Dominic

    The work presented in this paper describes an exploratory investigation into the potential effects of a robot exhibiting an adaptive behaviour in reaction to a child’s interaction. In our laboratory we develop robotic devices for a diverse range of children that differ in age, gender and ability, which includes children that are diagnosed with cognitive difficulties. As all children vary in their personalities and styles of interaction, it would follow that adaptation could bring many benefits. In this abstract we give our initial examination of a series of trials which explore the effects of a fully autonomous rolling robot exhibiting adaptation (through changes in motion and sound) compared to it exhibiting pre-programmed behaviours. We investigate sensor readings on-board the robot that record the level of ‘interaction’ that the robot receives when a child plays with it and also we discuss the results from analysing video footage looking at the social aspect of the trial.

  7. A Case-Study for Life-Long Learning and Adaptation in Cooperative Robot Teams

    International Nuclear Information System (INIS)

    Parker, L.E.

    1999-01-01

    While considerable progress has been made in recent years toward the development of multi-robot teams, much work remains to be done before these teams are used widely in real-world applications. Two particular needs toward this end are the development of mechanisms that enable robot teams to generate cooperative behaviors on their own, and the development of techniques that allow these teams to autonomously adapt their behavior over time as the environment or the robot team changes. This paper proposes the use of the Cooperative Multi-Robot Observation of Multiple Moving Targets (CMOMMT) application as a rich domain for studying the issues of multi-robot learning and adaptation. After discussing the need for learning and adaptation in multi-robot teams, this paper describes the CMOMMT application and its relevance to multi-robot learning. We discuss the results of the previously- developed, hand-generated algorithm for CMOMMT and the potential for learning that was discovered from the hand-generated approach. We then describe the early work that has been done (by us and others) to generate multi- robot learning techniques for the CMOMMT application, as well as our ongoing research to develop approaches that give performance as good, or better, than the hand-generated approach. The ultimate goal of this research is to develop techniques for multi-robot learning and adaptation in the CMOMMT application domain that will generalize to cooperative robot applications in other domains, thus making the practical use of multi-robot teams in a wide variety of real-world applications much closer to reality

  8. Estimating Position of Mobile Robots From Omnidirectional Vision Using an Adaptive Algorithm.

    Science.gov (United States)

    Li, Luyang; Liu, Yun-Hui; Wang, Kai; Fang, Mu

    2015-08-01

    This paper presents a novel and simple adaptive algorithm for estimating the position of a mobile robot with high accuracy in an unknown and unstructured environment by fusing images of an omnidirectional vision system with measurements of odometry and inertial sensors. Based on a new derivation where the omnidirectional projection can be linearly parameterized by the positions of the robot and natural feature points, we propose a novel adaptive algorithm, which is similar to the Slotine-Li algorithm in model-based adaptive control, to estimate the robot's position by using the tracked feature points in image sequence, the robot's velocity, and orientation angles measured by odometry and inertial sensors. It is proved that the adaptive algorithm leads to global exponential convergence of the position estimation errors to zero. Simulations and real-world experiments are performed to demonstrate the performance of the proposed algorithm.

  9. Efficacy of dry-ice blasting in preventive maintenance of auto robotic assemblies

    Science.gov (United States)

    Baluch, Nazim; Mohtar, Shahimi; Abdullah, Che Sobry

    2016-08-01

    Welding robots are extensively applied in the automotive assemblies and `Spot Welding' is the most common welding application found in the auto stamping assembly manufacturing. Every manufacturing process is subject to variations - with resistance welding, these include; part fit up, part thickness variations, misaligned electrodes, variations in coating materials or thickness, sealers, weld force variations, shunting, machine tooling degradation; and slag and spatter damage. All welding gun tips undergo wear; an elemental part of the process. Though adaptive resistance welding control automatically compensates to keep production and quality up to the levels needed as gun tips undergo wear so that the welds remain reliable; the system cannot compensate for deterioration caused by the slag and spatter on the part holding fixtures, sensors, and gun tips. To cleanse welding robots of slag and spatter, dry-ice blasting has proven to be an effective remedy. This paper describes Spot welding process, analyses the slag and spatter formation during robotic welding of stamping assemblies, and concludes that the dry ice blasting process's utility in cleansing of welding robots in auto stamping plant operations is paramount and exigent.

  10. Design and Optimal Research of a Non-Contact Adjustable Magnetic Adhesion Mechanism for a Wall-Climbing Welding Robot

    Directory of Open Access Journals (Sweden)

    Minghui Wu

    2013-01-01

    Full Text Available Wall-climbing welding robots (WCWRs can replace workers in manufacturing and maintaining large unstructured equipment, such as ships. The adhesion mechanism is the key component of WCWRs. As it is directly related to the robot's ability in relation to adsorbing, moving flexibly and obstacle-passing. In this paper, a novel non-contact adjustably magnetic adhesion mechanism is proposed. The magnet suckers are mounted under the robot's axils and the sucker and wall are in non-contact. In order to pass obstacles, the sucker and the wheel unit can be pulled up and pushed down by a lifting mechanism. The magnetic adhesion force can be adjusted by changing the height of the gap between the sucker and the wall by the lifting mechanism. In order to increase the adhesion force, the value of the sucker's magnetic energy density (MED is maximized by optimizing the magnet sucker's structure parameters with a finite element method. Experiments prove that the magnetic adhesion mechanism has enough adhesion force and that the WCWR can complete wall-climbing work within a large unstructured environment.

  11. Motion based segmentation for robot vision using adapted EM algorithm

    NARCIS (Netherlands)

    Zhao, Wei; Roos, Nico

    2016-01-01

    Robots operate in a dynamic world in which objects are often moving. The movement of objects may help the robot to segment the objects from the background. The result of the segmentation can subsequently be used to identify the objects. This paper investigates the possibility of segmenting objects

  12. Implementation of robust adaptive control for robotic manipulator using TMS320C30

    International Nuclear Information System (INIS)

    Han, S. H.

    1996-01-01

    A new adaptive digital control scheme for the robotic manipulator is proposed in this paper. Digital signal processors are used in implementing real time adaptive control algorithms to provide an enhanced motion for robotic manipulators. In the proposed scheme, adaptation laws are derived from the improved Lyapunov second stability analysis based on the adaptive feedforward and feedback controller and PI type time-varying control elements. The control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Moreover, this scheme does not require an accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the adaptive controller is illustrated by simulation and experimental results for a SCARA robot. (author)

  13. Adaptive training algorithm for robot-assisted upper-arm rehabilitation, applicable to individualised and therapeutic human-robot interaction.

    Science.gov (United States)

    Chemuturi, Radhika; Amirabdollahian, Farshid; Dautenhahn, Kerstin

    2013-09-28

    Rehabilitation robotics is progressing towards developing robots that can be used as advanced tools to augment the role of a therapist. These robots are capable of not only offering more frequent and more accessible therapies but also providing new insights into treatment effectiveness based on their ability to measure interaction parameters. A requirement for having more advanced therapies is to identify how robots can 'adapt' to each individual's needs at different stages of recovery. Hence, our research focused on developing an adaptive interface for the GENTLE/A rehabilitation system. The interface was based on a lead-lag performance model utilising the interaction between the human and the robot. The goal of the present study was to test the adaptability of the GENTLE/A system to the performance of the user. Point-to-point movements were executed using the HapticMaster (HM) robotic arm, the main component of the GENTLE/A rehabilitation system. The points were displayed as balls on the screen and some of the points also had a real object, providing a test-bed for the human-robot interaction (HRI) experiment. The HM was operated in various modes to test the adaptability of the GENTLE/A system based on the leading/lagging performance of the user. Thirty-two healthy participants took part in the experiment comprising of a training phase followed by the actual-performance phase. The leading or lagging role of the participant could be used successfully to adjust the duration required by that participant to execute point-to-point movements, in various modes of robot operation and under various conditions. The adaptability of the GENTLE/A system was clearly evident from the durations recorded. The regression results showed that the participants required lower execution times with the help from a real object when compared to just a virtual object. The 'reaching away' movements were longer to execute when compared to the 'returning towards' movements irrespective of the

  14. In-process monitoring and adaptive control for gap in micro butt welding with pulsed YAG laser

    International Nuclear Information System (INIS)

    Kawahito, Yousuke; Kito, Masayuki; Katayama, Seiji

    2007-01-01

    A gap is one of the most important issues to be solved in laser welding of a micro butt joint, because the gap results in welding defects such as underfilling or a non-bonded joint. In-process monitoring and adaptive control has been expected as one of the useful procedures for the stable production of sound laser welds without defects. The objective of this research is to evaluate the availability of in-process monitoring and adaptive control in micro butt welding of pure titanium rods with a pulsed neodymium : yttrium aluminium garnet (Nd : YAG) laser beam of a 150 μm spot diameter. It was revealed that a 45 μm narrow gap was detected by the remarkable jump in a reflected light intensity due to the formation of the molten pool which could bridge the gap. Heat radiation signal levels increased in proportion to the sizes of molten pools or penetration depths for the respective laser powers. As for adaptive control, the laser peak power was controlled on the basis of the reflected light or the heat radiation signals to stably produce a sound deeply penetrated weld reduced underfilling. In the case of a 100 μm gap, the underfilling was greatly reduced by half smaller than those made with a conventional rectangular pulse shape in seam welding as well as spot welding with a pulsed Nd : YAG laser beam. Consequently, the adaptive control of the laser peak power on the basis of in-process monitoring could reduce the harmful effects due to a gap in micro butt laser welding with a pulsed laser beam

  15. Adaptive robotic control driven by a versatile spiking cerebellar network.

    Directory of Open Access Journals (Sweden)

    Claudia Casellato

    Full Text Available The cerebellum is involved in a large number of different neural processes, especially in associative learning and in fine motor control. To develop a comprehensive theory of sensorimotor learning and control, it is crucial to determine the neural basis of coding and plasticity embedded into the cerebellar neural circuit and how they are translated into behavioral outcomes in learning paradigms. Learning has to be inferred from the interaction of an embodied system with its real environment, and the same cerebellar principles derived from cell physiology have to be able to drive a variety of tasks of different nature, calling for complex timing and movement patterns. We have coupled a realistic cerebellar spiking neural network (SNN with a real robot and challenged it in multiple diverse sensorimotor tasks. Encoding and decoding strategies based on neuronal firing rates were applied. Adaptive motor control protocols with acquisition and extinction phases have been designed and tested, including an associative Pavlovian task (Eye blinking classical conditioning, a vestibulo-ocular task and a perturbed arm reaching task operating in closed-loop. The SNN processed in real-time mossy fiber inputs as arbitrary contextual signals, irrespective of whether they conveyed a tone, a vestibular stimulus or the position of a limb. A bidirectional long-term plasticity rule implemented at parallel fibers-Purkinje cell synapses modulated the output activity in the deep cerebellar nuclei. In all tasks, the neurorobot learned to adjust timing and gain of the motor responses by tuning its output discharge. It succeeded in reproducing how human biological systems acquire, extinguish and express knowledge of a noisy and changing world. By varying stimuli and perturbations patterns, real-time control robustness and generalizability were validated. The implicit spiking dynamics of the cerebellar model fulfill timing, prediction and learning functions.

  16. Adaptive robotic control driven by a versatile spiking cerebellar network.

    Science.gov (United States)

    Casellato, Claudia; Antonietti, Alberto; Garrido, Jesus A; Carrillo, Richard R; Luque, Niceto R; Ros, Eduardo; Pedrocchi, Alessandra; D'Angelo, Egidio

    2014-01-01

    The cerebellum is involved in a large number of different neural processes, especially in associative learning and in fine motor control. To develop a comprehensive theory of sensorimotor learning and control, it is crucial to determine the neural basis of coding and plasticity embedded into the cerebellar neural circuit and how they are translated into behavioral outcomes in learning paradigms. Learning has to be inferred from the interaction of an embodied system with its real environment, and the same cerebellar principles derived from cell physiology have to be able to drive a variety of tasks of different nature, calling for complex timing and movement patterns. We have coupled a realistic cerebellar spiking neural network (SNN) with a real robot and challenged it in multiple diverse sensorimotor tasks. Encoding and decoding strategies based on neuronal firing rates were applied. Adaptive motor control protocols with acquisition and extinction phases have been designed and tested, including an associative Pavlovian task (Eye blinking classical conditioning), a vestibulo-ocular task and a perturbed arm reaching task operating in closed-loop. The SNN processed in real-time mossy fiber inputs as arbitrary contextual signals, irrespective of whether they conveyed a tone, a vestibular stimulus or the position of a limb. A bidirectional long-term plasticity rule implemented at parallel fibers-Purkinje cell synapses modulated the output activity in the deep cerebellar nuclei. In all tasks, the neurorobot learned to adjust timing and gain of the motor responses by tuning its output discharge. It succeeded in reproducing how human biological systems acquire, extinguish and express knowledge of a noisy and changing world. By varying stimuli and perturbations patterns, real-time control robustness and generalizability were validated. The implicit spiking dynamics of the cerebellar model fulfill timing, prediction and learning functions.

  17. Dynamic Modelling and Adaptive Traction Control for Mobile Robots

    Directory of Open Access Journals (Sweden)

    A. Albagul

    2004-09-01

    Full Text Available Mobile robots have received a great deal of research in recent years. A significant amount of research has been published in many aspects related to mobile robots. Most of the research is devoted to design and develop some control techniques for robot motion and path planning. A large number of researchers have used kinematic models to develop motion control strategy for mobile robots. Their argument and assumption that these models are valid if the robot has low speed, low acceleration and light load. However, dynamic modelling of mobile robots is very important as they are designed to travel at higher speed and perform heavy duty work. This paper presents and discusses a new approach to develop a dynamic model and control strategy for wheeled mobile robot which I modelled as a rigid body that roles on two wheels and a castor. The motion control strategy consists of two levels. The first level is dealing with the dynamic of the system and denoted as ‘Low’ level controller. The second level is developed to take care of path planning and trajectory generation.

  18. Adaptive Neuro-Fuzzy Inference System (ANFIS)-Based Models for Predicting the Weld Bead Width and Depth of Penetration from the Infrared Thermal Image of the Weld Pool

    Science.gov (United States)

    Subashini, L.; Vasudevan, M.

    2012-02-01

    Type 316 LN stainless steel is the major structural material used in the construction of nuclear reactors. Activated flux tungsten inert gas (A-TIG) welding has been developed to increase the depth of penetration because the depth of penetration achievable in single-pass TIG welding is limited. Real-time monitoring and control of weld processes is gaining importance because of the requirement of remoter welding process technologies. Hence, it is essential to develop computational methodologies based on an adaptive neuro fuzzy inference system (ANFIS) or artificial neural network (ANN) for predicting and controlling the depth of penetration and weld bead width during A-TIG welding of type 316 LN stainless steel. In the current work, A-TIG welding experiments have been carried out on 6-mm-thick plates of 316 LN stainless steel by varying the welding current. During welding, infrared (IR) thermal images of the weld pool have been acquired in real time, and the features have been extracted from the IR thermal images of the weld pool. The welding current values, along with the extracted features such as length, width of the hot spot, thermal area determined from the Gaussian fit, and thermal bead width computed from the first derivative curve were used as inputs, whereas the measured depth of penetration and weld bead width were used as output of the respective models. Accurate ANFIS models have been developed for predicting the depth of penetration and the weld bead width during TIG welding of 6-mm-thick 316 LN stainless steel plates. A good correlation between the measured and predicted values of weld bead width and depth of penetration were observed in the developed models. The performance of the ANFIS models are compared with that of the ANN models.

  19. Adaptive training of neural networks for control of autonomous mobile robots

    NARCIS (Netherlands)

    Steur, E.; Vromen, T.; Nijmeijer, H.; Fossen, T.I.; Nijmeijer, H.; Pettersen, K.Y.

    2017-01-01

    We present an adaptive training procedure for a spiking neural network, which is used for control of a mobile robot. Because of manufacturing tolerances, any hardware implementation of a spiking neural network has non-identical nodes, which limit the performance of the controller. The adaptive

  20. Biologically inspired control of humanoid robot arms robust and adaptive approaches

    CERN Document Server

    Spiers, Adam; Herrmann, Guido

    2016-01-01

    This book investigates a biologically inspired method of robot arm control, developed with the objective of synthesising human-like motion dynamically, using nonlinear, robust and adaptive control techniques in practical robot systems. The control method caters to a rising interest in humanoid robots and the need for appropriate control schemes to match these systems. Unlike the classic kinematic schemes used in industrial manipulators, the dynamic approaches proposed here promote human-like motion with better exploitation of the robot’s physical structure. This also benefits human-robot interaction. The control schemes proposed in this book are inspired by a wealth of human-motion literature that indicates the drivers of motion to be dynamic, model-based and optimal. Such considerations lend themselves nicely to achievement via nonlinear control techniques without the necessity for extensive and complex biological models. The operational-space method of robot control forms the basis of many of the techniqu...

  1. Supervisory Adaptive Network-Based Fuzzy Inference System (SANFIS Design for Empirical Test of Mobile Robot

    Directory of Open Access Journals (Sweden)

    Yi-Jen Mon

    2012-10-01

    Full Text Available A supervisory Adaptive Network-based Fuzzy Inference System (SANFIS is proposed for the empirical control of a mobile robot. This controller includes an ANFIS controller and a supervisory controller. The ANFIS controller is off-line tuned by an adaptive fuzzy inference system, the supervisory controller is designed to compensate for the approximation error between the ANFIS controller and the ideal controller, and drive the trajectory of the system onto a specified surface (called the sliding surface or switching surface while maintaining the trajectory onto this switching surface continuously to guarantee the system stability. This SANFIS controller can achieve favourable empirical control performance of the mobile robot in the empirical tests of driving the mobile robot with a square path. Practical experimental results demonstrate that the proposed SANFIS can achieve better control performance than that achieved using an ANFIS controller for empirical control of the mobile robot.

  2. A Novel Greeting Selection System for a Culture-Adaptive Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Gabriele Trovato

    2015-04-01

    Full Text Available Robots, especially humanoids, are expected to perform human-like actions and adapt to our ways of communication in order to facilitate their acceptance in human society. Among humans, rules of communication change depending on background culture: greetings are a part of communication in which cultural differences are strong. Robots should adapt to these specific differences in order to communicate effectively, being able to select the appropriate manner of greeting for different cultures depending on the social context. In this paper, we present the modelling of social factors that influence greeting choice, and the resulting novel culture-dependent greeting gesture and words selection system. An experiment with German participants was run using the humanoid robot ARMAR-IIIb. Thanks to this system, the robot, after interacting with Germans, can perform greeting gestures appropriate to German culture in addition to a repertoire of greetings appropriate to Japanese culture.

  3. Prediction of Tensile Strength of Friction Stir Weld Joints with Adaptive Neuro-Fuzzy Inference System (ANFIS) and Neural Network

    Science.gov (United States)

    Dewan, Mohammad W.; Huggett, Daniel J.; Liao, T. Warren; Wahab, Muhammad A.; Okeil, Ayman M.

    2015-01-01

    Friction-stir-welding (FSW) is a solid-state joining process where joint properties are dependent on welding process parameters. In the current study three critical process parameters including spindle speed (??), plunge force (????), and welding speed (??) are considered key factors in the determination of ultimate tensile strength (UTS) of welded aluminum alloy joints. A total of 73 weld schedules were welded and tensile properties were subsequently obtained experimentally. It is observed that all three process parameters have direct influence on UTS of the welded joints. Utilizing experimental data, an optimized adaptive neuro-fuzzy inference system (ANFIS) model has been developed to predict UTS of FSW joints. A total of 1200 models were developed by varying the number of membership functions (MFs), type of MFs, and combination of four input variables (??,??,????,??????) utilizing a MATLAB platform. Note EFI denotes an empirical force index derived from the three process parameters. For comparison, optimized artificial neural network (ANN) models were also developed to predict UTS from FSW process parameters. By comparing ANFIS and ANN predicted results, it was found that optimized ANFIS models provide better results than ANN. This newly developed best ANFIS model could be utilized for prediction of UTS of FSW joints.

  4. Study on Laser Welding Process Monitoring Method

    OpenAIRE

    Knag , Heeshin

    2017-01-01

    International audience; In this paper, a study of quality monitoring technology for the laser welding was conducted. The laser welding and the industrial robotic systems were used with robot-based laser welding systems. The laser system used in this study was 1.6 kW fiber laser, while the robot system was Industrial robot (pay-load : 130 kg). The robot-based laser welding system was equipped with a laser scanner system for remote laser welding. The welding joints of steel plate and steel plat...

  5. Study on Laser Welding Process Monitoring Method

    OpenAIRE

    Heeshin Knag

    2016-01-01

    In this paper, a study of quality monitoring technology for the laser welding was conducted. The laser welding and the industrial robotic systems were used with robot-based laser welding systems. The laser system used in this study was 1.6 kW fiber laser, while the robot system was Industrial robot (pay-load : 130 kg). The robot-based laser welding system was equipped with a laser scanner system for remote laser welding. The welding joints of steel plate and steel plate coated with zinc were ...

  6. The quadruped robot adaptive control in trotting gait walking on slopes

    Science.gov (United States)

    Zhang, Shulong; Ma, Hongxu; Yang, Yu; Wang, Jian

    2017-10-01

    The quadruped robot can be decomposed into a planar seven-link closed kinematic chain in the direction of supporting line and a linear inverted pendulum in normal direction of supporting line. The ground slope can be estimated by using the body attitude information and supporting legs length. The slope degree is used in feedback, to achieve the point of quadruped robot adaptive control walking on slopes. The simulation results verify that the quadruped robot can achieves steady locomotion on the slope with the control strategy proposed in this passage.

  7. Precise 3D Lug Pose Detection Sensor for Automatic Robot Welding Using a Structured-Light Vision System

    Directory of Open Access Journals (Sweden)

    Il Jae Lee

    2009-09-01

    Full Text Available In this study, we propose a precise 3D lug pose detection sensor for automatic robot welding of a lug to a huge steel plate used in shipbuilding, where the lug is a handle to carry the huge steel plate. The proposed sensor consists of a camera and four laser line diodes, and its design parameters are determined by analyzing its detectable range and resolution. For the lug pose acquisition, four laser lines are projected on both lug and plate, and the projected lines are detected by the camera. For robust detection of the projected lines against the illumination change, the vertical threshold, thinning, Hough transform and separated Hough transform algorithms are successively applied to the camera image. The lug pose acquisition is carried out by two stages: the top view alignment and the side view alignment. The top view alignment is to detect the coarse lug pose relatively far from the lug, and the side view alignment is to detect the fine lug pose close to the lug. After the top view alignment, the robot is controlled to move close to the side of the lug for the side view alignment. By this way, the precise 3D lug pose can be obtained. Finally, experiments with the sensor prototype are carried out to verify the feasibility and effectiveness of the proposed sensor.

  8. Multi-optimization Criteria-based Robot Behavioral Adaptability and Motion Planning

    International Nuclear Information System (INIS)

    Pin, Francois G.

    2002-01-01

    Robotic tasks are typically defined in Task Space (e.g., the 3-D World), whereas robots are controlled in Joint Space (motors). The transformation from Task Space to Joint Space must consider the task objectives (e.g., high precision, strength optimization, torque optimization), the task constraints (e.g., obstacles, joint limits, non-holonomic constraints, contact or tool task constraints), and the robot kinematics configuration (e.g., tools, type of joints, mobile platform, manipulator, modular additions, locked joints). Commercially available robots are optimized for a specific set of tasks, objectives and constraints and, therefore, their control codes are extremely specific to a particular set of conditions. Thus, there exist a multiplicity of codes, each handling a particular set of conditions, but none suitable for use on robots with widely varying tasks, objectives, constraints, or environments. On the other hand, most DOE missions and tasks are typically ''batches of one''. Attempting to use commercial codes for such work requires significant personnel and schedule costs for re-programming or adding code to the robots whenever a change in task objective, robot configuration, number and type of constraint, etc. occurs. The objective of our project is to develop a ''generic code'' to implement this Task-space to Joint-Space transformation that would allow robot behavior adaptation, in real time (at loop rate), to changes in task objectives, number and type of constraints, modes of controls, kinematics configuration (e.g., new tools, added module). Our specific goal is to develop a single code for the general solution of under-specified systems of algebraic equations that is suitable for solving the inverse kinematics of robots, is useable for all types of robots (mobile robots, manipulators, mobile manipulators, etc.) with no limitation on the number of joints and the number of controlled Task-Space variables, can adapt to real time changes in number and

  9. Adaptive Robotic Fabrication for Conditions of Material Inconsistency

    DEFF Research Database (Denmark)

    Nicholas, Paul; Zwierzycki, Mateusz; Clausen Nørgaard, Esben

    2017-01-01

    This paper describes research that addresses the variable behaviour of industrial quality metals and the extension of computational techniques into the fabrication process. It describes the context of robotic incremental sheet metal forming, a freeform method for imparting 3D form onto a 2D thin ...... is an offline predictive strategy based on machine learning. Rigidisation of thin metal skins......This paper describes research that addresses the variable behaviour of industrial quality metals and the extension of computational techniques into the fabrication process. It describes the context of robotic incremental sheet metal forming, a freeform method for imparting 3D form onto a 2D thin...

  10. Obstacle avoidance for kinematically redundant robots using an adaptive fuzzy logic algorithm

    International Nuclear Information System (INIS)

    Beheshti, M.T.H.; Tehrani, A.K.

    1999-05-01

    In this paper the Adaptive Fuzzy Logic approach for solving the inverse kinematics of redundant robots in an environment with obstacles is presented. The obstacles are modeled as convex bodies. A fuzzy rule base that is updated via an adaptive law is used to solve the inverse kinematic problem. Additional rules have been introduced to take care of the obstacles avoidance problem. The proposed method has advantages such as high accuracy, simplicity of computations and generality for all redundant robots. Simulation results illustrate much better tracking performance than the dynamic base solution for a given trajectory in cartesian space, while guaranteeing a collision-free trajectory and observation of a mechanical joint limit

  11. Adaptive Visual Face Tracking for an Autonomous Robot

    NARCIS (Netherlands)

    van Hoof, Herke; van der Zant, Tijn; Wiering, Marco

    2011-01-01

    Perception is an essential ability for autonomous robots in non-standardized conditions. However, the appearance of objects can change between different conditions. A system visually tracking a target based on its appearance could lose its target in those cases. A tracker learning the appearance of

  12. An Adaptive Game Algorithm for an Autonomous, Mobile Robot

    DEFF Research Database (Denmark)

    Hansen, Søren Tranberg; Bak, Thomas; Risager, Claus

    2012-01-01

    This paper presents a field study of a physical ball game for elderly based on an autonomous, mobile robot. The game algorithm is based on Case Based Reasoning and adjusts the game challenge to the player’s mobility skills by registering the spatio-temporal behaviour of the player using an on boa...

  13. Synthesis of adaptive impedance control for bipedal robot mechanisms

    OpenAIRE

    Petrović Milena; Rodić Aleksandar

    2008-01-01

    The paper describes the impedance algorithm in locomotion of humanoid robot with proposed parameter modulation depending on the gate phase. The analysis shows influence of walking speed and foot elevation on regulator's parameters. Chosen criterion cares for footpath tracking and needed energy for that way of walking. The experiments give recommendation for impedance regulator tuning.

  14. Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.

    Science.gov (United States)

    Haasdijk, Evert; Bredeche, Nicolas; Eiben, A E

    2014-01-01

    Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-)adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability), and secondly they must competently perform user-specified tasks (usefulness). The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee) framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

  15. Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.

    Directory of Open Access Journals (Sweden)

    Evert Haasdijk

    Full Text Available Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability, and secondly they must competently perform user-specified tasks (usefulness. The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

  16. Experience and Applications Up-date: Automation of Arc-Welding Operations Using Robot-Technology; Experiencia y actualizacion de las aplicaciones: automatizacion de las operaciones de soldadura utilizando tecnologia robotica

    Energy Technology Data Exchange (ETDEWEB)

    Teubel, G

    1997-12-31

    In a short introduction, the important criteria for the correct choice of a robot cell, taking into account the given application, are highlighted. Furthermore, important hints are listed in terms of management decisions. The second chapter shows the main features of a welding robot cell in line with the present state of the art and describes some new developments with the aim of extending the arc-welding system to new applications such as flame cutting and beveling. The third chapter as centre piece gives an overall view of a brand new network control with many outstanding features for the users of arc-welding robots. the fourth and last chapter shows a recent realisation of a highly sophisticated F.M.S. system for welding, in random sequence, different large and heavy components. (Author) 1 ref.

  17. Arousal regulation and affective adaptation to human responsiveness by a robot that explores and learns a novel environment.

    Science.gov (United States)

    Hiolle, Antoine; Lewis, Matthew; Cañamero, Lola

    2014-01-01

    In the context of our work in developmental robotics regarding robot-human caregiver interactions, in this paper we investigate how a "baby" robot that explores and learns novel environments can adapt its affective regulatory behavior of soliciting help from a "caregiver" to the preferences shown by the caregiver in terms of varying responsiveness. We build on two strands of previous work that assessed independently (a) the differences between two "idealized" robot profiles-a "needy" and an "independent" robot-in terms of their use of a caregiver as a means to regulate the "stress" (arousal) produced by the exploration and learning of a novel environment, and (b) the effects on the robot behaviors of two caregiving profiles varying in their responsiveness-"responsive" and "non-responsive"-to the regulatory requests of the robot. Going beyond previous work, in this paper we (a) assess the effects that the varying regulatory behavior of the two robot profiles has on the exploratory and learning patterns of the robots; (b) bring together the two strands previously investigated in isolation and take a step further by endowing the robot with the capability to adapt its regulatory behavior along the "needy" and "independent" axis as a function of the varying responsiveness of the caregiver; and (c) analyze the effects that the varying regulatory behavior has on the exploratory and learning patterns of the adaptive robot.

  18. Periodic activations of behaviours and emotional adaptation in behaviour-based robotics

    Science.gov (United States)

    Burattini, Ernesto; Rossi, Silvia

    2010-09-01

    The possible modulatory influence of motivations and emotions is of great interest in designing robotic adaptive systems. In this paper, an attempt is made to connect the concept of periodic behaviour activations to emotional modulation, in order to link the variability of behaviours to the circumstances in which they are activated. The impact of emotion is studied, described as timed controlled structures, on simple but conflicting reactive behaviours. Through this approach it is shown that the introduction of such asynchronies in the robot control system may lead to an adaptation in the emergent behaviour without having an explicit action selection mechanism. The emergent behaviours of a simple robot designed with both a parallel and a hierarchical architecture are evaluated and compared.

  19. Fuzzy Adaptation Algorithms’ Control for Robot Manipulators with Uncertainty Modelling Errors

    Directory of Open Access Journals (Sweden)

    Yongqing Fan

    2018-01-01

    Full Text Available A novel fuzzy control scheme with adaptation algorithms is developed for robot manipulators’ system. At the beginning, one adjustable parameter is introduced in the fuzzy logic system, the robot manipulators system with uncertain nonlinear terms as the master device and a reference model dynamic system as the slave robot system. To overcome the limitations such as online learning computation burden and logic structure in conventional fuzzy logic systems, a parameter should be used in fuzzy logic system, which composes fuzzy logic system with updated parameter laws, and can be formed for a new fashioned adaptation algorithms controller. The error closed-loop dynamical system can be stabilized based on Lyapunov analysis, the number of online learning computation burdens can be reduced greatly, and the different kinds of fuzzy logic systems with fuzzy rules or without any fuzzy rules are also suited. Finally, effectiveness of the proposed approach has been shown in simulation example.

  20. Adaptive Neural Output Feedback Control for Uncertain Robot Manipulators with Input Saturation

    Directory of Open Access Journals (Sweden)

    Rong Mei

    2017-01-01

    Full Text Available This paper presents an adaptive neural output feedback control scheme for uncertain robot manipulators with input saturation using the radial basis function neural network (RBFNN and disturbance observer. First, the RBFNN is used to approximate the system uncertainty, and the unknown approximation error of the RBFNN and the time-varying unknown external disturbance of robot manipulators are integrated as a compounded disturbance. Then, the state observer and the disturbance observer are proposed to estimate the unmeasured system state and the unknown compounded disturbance based on RBFNN. At the same time, the adaptation technique is employed to tackle the control input saturation problem. Utilizing the estimate outputs of the RBFNN, the state observer, and the disturbance observer, the adaptive neural output feedback control scheme is developed for robot manipulators using the backstepping technique. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis and the asymptotically convergent tracking error is obtained under the integrated effect of the system uncertainty, the unmeasured system state, the unknown external disturbance, and the input saturation. Finally, numerical simulation results are presented to illustrate the effectiveness of the proposed adaptive neural output feedback control scheme for uncertain robot manipulators.

  1. Alignment Condition-Based Robust Adaptive Iterative Learning Control of Uncertain Robot System

    Directory of Open Access Journals (Sweden)

    Guofeng Tong

    2014-04-01

    Full Text Available This paper proposes an adaptive iterative learning control strategy integrated with saturation-based robust control for uncertain robot system in presence of modelling uncertainties, unknown parameter, and external disturbance under alignment condition. An important merit is that it achieves adaptive switching of gain matrix both in conventional PD-type feedforward control and robust adaptive control in the iteration domain simultaneously. The analysis of convergence of proposed control law is based on Lyapunov's direct method under alignment initial condition. Simulation results demonstrate the faster learning rate and better robust performance with proposed algorithm by comparing with other existing robust controllers. The actual experiment on three-DOF robot manipulator shows its better practical effectiveness.

  2. Adaptive PID formation control of nonholonomic robots without leader's velocity information.

    Science.gov (United States)

    Shen, Dongbin; Sun, Weijie; Sun, Zhendong

    2014-03-01

    This paper proposes an adaptive proportional integral derivative (PID) algorithm to solve a formation control problem in the leader-follower framework where the leader robot's velocities are unknown for the follower robots. The main idea is first to design some proper ideal control law for the formation system to obtain a required performance, and then to propose the adaptive PID methodology to approach the ideal controller. As a result, the formation is achieved with much more enhanced robust formation performance. The stability of the closed-loop system is theoretically proved by Lyapunov method. Both numerical simulations and physical vehicle experiments are presented to verify the effectiveness of the proposed adaptive PID algorithm. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Adaptive control of an exoskeleton robot with uncertainties on kinematics and dynamics.

    Science.gov (United States)

    Brahmi, Brahim; Saad, Maarouf; Ochoa-Luna, Cristobal; Rahman, Mohammad H

    2017-07-01

    In this paper, we propose a new adaptive control technique based on nonlinear sliding mode control (JSTDE) taking into account kinematics and dynamics uncertainties. This approach is applied to an exoskeleton robot with uncertain kinematics and dynamics. The adaptation design is based on Time Delay Estimation (TDE). The proposed strategy does not necessitate the well-defined dynamic and kinematic models of the system robot. The updated laws are designed using Lyapunov-function to solve the adaptation problem systematically, proving the close loop stability and ensuring the convergence asymptotically of the outputs tracking errors. Experiments results show the effectiveness and feasibility of JSTDE technique to deal with the variation of the unknown nonlinear dynamics and kinematics of the exoskeleton model.

  4. Adapting a robotics program to enhance participation and interest in STEM among children with disabilities: a pilot study.

    Science.gov (United States)

    Lindsay, Sally; Hounsell, Kara Grace

    2017-10-01

    Youth with disabilities are under-represented in science, technology, engineering, and math (STEM) in school and in the workforce. One encouraging approach to engage youth's interest in STEM is through robotics; however, such programs are mostly for typically developing youth. The purpose of this study was to understand the development and implementation of an adapted robotics program for children and youth with disabilities and their experiences within it. Our mixed methods pilot study (pre- and post-workshop surveys, observations, and interviews) involved 41 participants including: 18 youth (aged 6-13), 12 parents and 11 key informants. The robotics program involved 6, two-hour workshops held at a paediatric hospital. Our findings showed that several adaptations made to the robotics program helped to enhance the participation of children with disabilities. Adaptations addressed the educational/curriculum, cognitive and learning, physical and social needs of the children. In regards to experiences within the adapted hospital program, our findings highlight that children enjoyed the program and learned about computer programming and building robots. Clinicians and educators should consider engaging youth with disabilities in robotics to enhance learning and interest in STEM. Implications for Rehabilitation Clinicians and educators should consider adapting curriculum content and mode of delivery of LEGO ® robotics programs to include youth with disabilities. Appropriate staffing including clinicians and educators who are knowledgeable about youth with disabilities and LEGO ® robotics are needed. Clinicians should consider engaging youth with disabilities in LEGO ® to enhance learning and interest in STEM.

  5. Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot.

    Science.gov (United States)

    Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin; Manoonpong, Poramate

    2015-01-01

    Walking animals, like insects, with little neural computing can effectively perform complex behaviors. For example, they can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking robot. The turning information is transmitted as descending steering signals to the neural locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations. The adaptation also enables the robot to effectively escape from sharp corners or deadlocks. Using backbone joint control embedded in the the locomotion control allows the robot to climb over small obstacles

  6. Adaptive Inverse Optimal Control for Rehabilitation Robot Systems Using Actor-Critic Algorithm

    Directory of Open Access Journals (Sweden)

    Fancheng Meng

    2014-01-01

    Full Text Available The higher goal of rehabilitation robot is to aid a person to achieve a desired functional task (e.g., tracking trajectory based on assisted-as-needed principle. To this goal, a new adaptive inverse optimal hybrid control (AHC combining inverse optimal control and actor-critic learning is proposed. Specifically, an uncertain nonlinear rehabilitation robot model is firstly developed that includes human motor behavior dynamics. Then, based on this model, an open-loop error system is formed; thereafter, an inverse optimal control input is designed to minimize the cost functional and a NN-based actor-critic feedforward signal is responsible for the nonlinear dynamic part contaminated by uncertainties. Finally, the AHC controller is proven (through a Lyapunov-based stability analysis to yield a global uniformly ultimately bounded stability result, and the resulting cost functional is meaningful. Simulation and experiment on rehabilitation robot demonstrate the effectiveness of the proposed control scheme.

  7. Adaptive Human-Aware Robot Navigation in Close Proximity to Humans

    DEFF Research Database (Denmark)

    Svenstrup, Mikael; Hansen, Søren Tranberg; Andersen, Hans Jørgen

    2011-01-01

    For robots to be able coexist with people in future everyday human environments, they must be able to act in a safe, natural and comfortable way. This work addresses the motion of a mobile robot in an environment, where humans potentially want to interact with it. The designed system consists...... system that uses a potential field to derive motion that respects the personʹs social zones and perceived interest in interaction. The operation of the system is evaluated in a controlled scenario in an open hall environment. It is demonstrated that the robot is able to learn to estimate if a person...... wishes to interact, and that the system is capable of adapting to changing behaviours of the humans in the environment....

  8. Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot

    Directory of Open Access Journals (Sweden)

    Eduard eGrinke

    2015-10-01

    Full Text Available Walking animals, like insects, with little neural computing can effectively perform complex behaviors. They can walk around their environment, escape from corners/deadlocks, and avoid or climb over obstacles. While performing all these behaviors, they can also adapt their movements to deal with an unknown situation. As a consequence, they successfully navigate through their complex environment. The versatile and adaptive abilities are the result of an integration of several ingredients embedded in their sensorimotor loop. Biological studies reveal that the ingredients include neural dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a walking robot is a challenging task. In this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural mechanisms with plasticity, sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent network consisting of two fully connected neurons. Online correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors in the network to generate different turning angles with short-term memory for a biomechanical walking robot. The turning information is transmitted as descending steering signals to the locomotion control which translates the signals into motor actions. As a result, the robot can walk around and adapt its turning angle for avoiding obstacles in different situations as well as escaping from sharp corners or deadlocks. Using backbone joint control embedded in the locomotion control allows the robot to climb over small obstacles. Consequently, it can successfully explore and navigate in complex environments.

  9. An Adaptive Multi-Objective Particle Swarm Optimization Algorithm for Multi-Robot Path Planning

    Directory of Open Access Journals (Sweden)

    Nizar Hadi Abbas

    2016-07-01

    Full Text Available This paper discusses an optimal path planning algorithm based on an Adaptive Multi-Objective Particle Swarm Optimization Algorithm (AMOPSO for two case studies. First case, single robot wants to reach a goal in the static environment that contain two obstacles and two danger source. The second one, is improving the ability for five robots to reach the shortest way. The proposed algorithm solves the optimization problems for the first case by finding the minimum distance from initial to goal position and also ensuring that the generated path has a maximum distance from the danger zones. And for the second case, finding the shortest path for every robot and without any collision between them with the shortest time. In order to evaluate the proposed algorithm in term of finding the best solution, six benchmark test functions are used to make a comparison between AMOPSO and the standard MOPSO. The results show that the AMOPSO has a better ability to get away from local optimums with a quickest convergence than the MOPSO. The simulation results using Matlab 2014a, indicate that this methodology is extremely valuable for every robot in multi-robot framework to discover its own particular proper pa‌th from the start to the destination position with minimum distance and time.

  10. Emergent adaptive behaviour of GRN-controlled simulated robots in a changing environment

    Directory of Open Access Journals (Sweden)

    Yao Yao

    2016-12-01

    Full Text Available We developed a bio-inspired robot controller combining an artificial genome with an agent-based control system. The genome encodes a gene regulatory network (GRN that is switched on by environmental cues and, following the rules of transcriptional regulation, provides output signals to actuators. Whereas the genome represents the full encoding of the transcriptional network, the agent-based system mimics the active regulatory network and signal transduction system also present in naturally occurring biological systems. Using such a design that separates the static from the conditionally active part of the gene regulatory network contributes to a better general adaptive behaviour. Here, we have explored the potential of our platform with respect to the evolution of adaptive behaviour, such as preying when food becomes scarce, in a complex and changing environment and show through simulations of swarm robots in an A-life environment that evolution of collective behaviour likely can be attributed to bio-inspired evolutionary processes acting at different levels, from the gene and the genome to the individual robot and robot population.

  11. Emergent adaptive behaviour of GRN-controlled simulated robots in a changing environment.

    Science.gov (United States)

    Yao, Yao; Storme, Veronique; Marchal, Kathleen; Van de Peer, Yves

    2016-01-01

    We developed a bio-inspired robot controller combining an artificial genome with an agent-based control system. The genome encodes a gene regulatory network (GRN) that is switched on by environmental cues and, following the rules of transcriptional regulation, provides output signals to actuators. Whereas the genome represents the full encoding of the transcriptional network, the agent-based system mimics the active regulatory network and signal transduction system also present in naturally occurring biological systems. Using such a design that separates the static from the conditionally active part of the gene regulatory network contributes to a better general adaptive behaviour. Here, we have explored the potential of our platform with respect to the evolution of adaptive behaviour, such as preying when food becomes scarce, in a complex and changing environment and show through simulations of swarm robots in an A-life environment that evolution of collective behaviour likely can be attributed to bio-inspired evolutionary processes acting at different levels, from the gene and the genome to the individual robot and robot population.

  12. Emergent adaptive behaviour of GRN-controlled simulated robots in a changing environment

    Science.gov (United States)

    Yao, Yao; Storme, Veronique; Marchal, Kathleen

    2016-01-01

    We developed a bio-inspired robot controller combining an artificial genome with an agent-based control system. The genome encodes a gene regulatory network (GRN) that is switched on by environmental cues and, following the rules of transcriptional regulation, provides output signals to actuators. Whereas the genome represents the full encoding of the transcriptional network, the agent-based system mimics the active regulatory network and signal transduction system also present in naturally occurring biological systems. Using such a design that separates the static from the conditionally active part of the gene regulatory network contributes to a better general adaptive behaviour. Here, we have explored the potential of our platform with respect to the evolution of adaptive behaviour, such as preying when food becomes scarce, in a complex and changing environment and show through simulations of swarm robots in an A-life environment that evolution of collective behaviour likely can be attributed to bio-inspired evolutionary processes acting at different levels, from the gene and the genome to the individual robot and robot population. PMID:28028477

  13. Robotics

    Energy Technology Data Exchange (ETDEWEB)

    Lorino, P; Altwegg, J M

    1985-05-01

    This article, which is aimed at the general reader, examines latest developments in, and the role of, modern robotics. The 7 main sections are sub-divided into 27 papers presented by 30 authors. The sections are as follows: 1) The role of robotics, 2) Robotics in the business world and what it can offer, 3) Study and development, 4) Utilisation, 5) Wages, 6) Conditions for success, and 7) Technological dynamics.

  14. Improving the adaptability of simulated evolutionary swarm robots in dynamically changing environments.

    Directory of Open Access Journals (Sweden)

    Yao Yao

    Full Text Available One of the important challenges in the field of evolutionary robotics is the development of systems that can adapt to a changing environment. However, the ability to adapt to unknown and fluctuating environments is not straightforward. Here, we explore the adaptive potential of simulated swarm robots that contain a genomic encoding of a bio-inspired gene regulatory network (GRN. An artificial genome is combined with a flexible agent-based system, representing the activated part of the regulatory network that transduces environmental cues into phenotypic behaviour. Using an artificial life simulation framework that mimics a dynamically changing environment, we show that separating the static from the conditionally active part of the network contributes to a better adaptive behaviour. Furthermore, in contrast with most hitherto developed ANN-based systems that need to re-optimize their complete controller network from scratch each time they are subjected to novel conditions, our system uses its genome to store GRNs whose performance was optimized under a particular environmental condition for a sufficiently long time. When subjected to a new environment, the previous condition-specific GRN might become inactivated, but remains present. This ability to store 'good behaviour' and to disconnect it from the novel rewiring that is essential under a new condition allows faster re-adaptation if any of the previously observed environmental conditions is reencountered. As we show here, applying these evolutionary-based principles leads to accelerated and improved adaptive evolution in a non-stable environment.

  15. Improving the Adaptability of Simulated Evolutionary Swarm Robots in Dynamically Changing Environments

    Science.gov (United States)

    Yao, Yao; Marchal, Kathleen; Van de Peer, Yves

    2014-01-01

    One of the important challenges in the field of evolutionary robotics is the development of systems that can adapt to a changing environment. However, the ability to adapt to unknown and fluctuating environments is not straightforward. Here, we explore the adaptive potential of simulated swarm robots that contain a genomic encoding of a bio-inspired gene regulatory network (GRN). An artificial genome is combined with a flexible agent-based system, representing the activated part of the regulatory network that transduces environmental cues into phenotypic behaviour. Using an artificial life simulation framework that mimics a dynamically changing environment, we show that separating the static from the conditionally active part of the network contributes to a better adaptive behaviour. Furthermore, in contrast with most hitherto developed ANN-based systems that need to re-optimize their complete controller network from scratch each time they are subjected to novel conditions, our system uses its genome to store GRNs whose performance was optimized under a particular environmental condition for a sufficiently long time. When subjected to a new environment, the previous condition-specific GRN might become inactivated, but remains present. This ability to store ‘good behaviour’ and to disconnect it from the novel rewiring that is essential under a new condition allows faster re-adaptation if any of the previously observed environmental conditions is reencountered. As we show here, applying these evolutionary-based principles leads to accelerated and improved adaptive evolution in a non-stable environment. PMID:24599485

  16. Adaptation of sensor morphology: an integrative view of perception from biologically inspired robotics perspective

    Science.gov (United States)

    Nurzaman, Surya G.

    2016-01-01

    Sensor morphology, the morphology of a sensing mechanism which plays a role of shaping the desired response from physical stimuli from surroundings to generate signals usable as sensory information, is one of the key common aspects of sensing processes. This paper presents a structured review of researches on bioinspired sensor morphology implemented in robotic systems, and discusses the fundamental design principles. Based on literature review, we propose two key arguments: first, owing to its synthetic nature, biologically inspired robotics approach is a unique and powerful methodology to understand the role of sensor morphology and how it can evolve and adapt to its task and environment. Second, a consideration of an integrative view of perception by looking into multidisciplinary and overarching mechanisms of sensor morphology adaptation across biology and engineering enables us to extract relevant design principles that are important to extend our understanding of the unfinished concepts in sensing and perception. PMID:27499843

  17. Adaptive and Energy Efficient Walking in a Hexapod Robot under Neuromechanical Control and Sensorimotor Learning

    DEFF Research Database (Denmark)

    Xiong, Xiaofeng; Wörgötter, Florentin; Manoonpong, Poramate

    2016-01-01

    The control of multilegged animal walking is a neuromechanical process, and to achieve this in an adaptive and energy efficient way is a difficult and challenging problem. This is due to the fact that this process needs in real time: 1) to coordinate very many degrees of freedom of jointed legs; 2......) to generate the proper leg stiffness (i.e., compliance); and 3) to determine joint angles that give rise to particular positions at the endpoints of the legs. To tackle this problem for a robotic application, here we present a neuromechanical controller coupled with sensorimotor learning. The controller...... energy efficient walking, compared to other small legged robots. In addition, this paper also shows that the tight combination of neural control with tunable muscle-like functions, guided by sensory feedback and coupled with sensorimotor learning, is a way forward to better understand and solve adaptive...

  18. Novel Adaptive Forward Neural MIMO NARX Model for the Identification of Industrial 3-DOF Robot Arm Kinematics

    OpenAIRE

    Ho Pham Huy Anh; Nguyen Thanh Nam

    2012-01-01

    In this paper, a novel forward adaptive neural MIMO NARX model is used for modelling and identifying the forward kinematics of an industrial 3‐DOF robot arm system. The nonlinear features of the forward kinematics of the industrial robot arm drive are thoroughly modelled based on the forward adaptive neural NARX model‐based identification process using experimental input‐output training data. This paper proposes a novel use of a back propagation (BP) algorithm to generate the forward neural M...

  19. Fuzzy adaptive robust control for space robot considering the effect of the gravity

    Directory of Open Access Journals (Sweden)

    Qin Li

    2014-12-01

    Full Text Available Space robot is assembled and tested in gravity environment, and completes on-orbit service (OOS in microgravity environment. The kinematic and dynamic characteristic of the robot will change with the variations of gravity in different working condition. Fully considering the change of kinematic and dynamic models caused by the change of gravity environment, a fuzzy adaptive robust control (FARC strategy which is adaptive to these model variations is put forward for trajectory tracking control of space robot. A fuzzy algorithm is employed to approximate the nonlinear uncertainties in the model, adaptive laws of the parameters are constructed, and the approximation error is compensated by using a robust control algorithm. The stability of the control system is guaranteed based on the Lyapunov theory and the trajectory tracking control simulation is performed. The simulation results are compared with the proportional plus derivative (PD controller, and the effectiveness to achieve better trajectory tracking performance under different gravity environment without changing the control parameters and the advantage of the proposed controller are verified.

  20. Adaptive Controller for 6-DOF Parallel Robot Using T-S Fuzzy Inference

    Directory of Open Access Journals (Sweden)

    Xue Jian

    2013-02-01

    Full Text Available 6-DOF parallel robot always appears in the form of Stewart platform. It has been widely used in industry for the benefits such as strong structural stiffness, high movement accuracy and so on. Space docking technology makes higher requirements of motion accuracy and dynamic performance to the control method on 6-DOF parallel robot. In this paper, a hydraulic 6-DOF parallel robot was used to simulate the docking process. Based on this point, this paper gave a thorough study on the design of an adaptive controller to eliminate the asymmetric of controlled plant and uncertain load force interference. Takagi-Sugeno (T-S fuzzy inference model was used to build the fuzzy adaptive controller. With T-S model, the controller directly imposes adaptive control signal on the plant to make sure that the output of plant could track the reference model output. The controller has simple structure and is easy to implement. Experiment results show that the controller can eliminate asymmetric and achieve good dynamic performance, and has good robustness to load interference.

  1. Modbus RTU protocol and arduino IO package: A real time implementation of a 3 finger adaptive robot gripper

    Directory of Open Access Journals (Sweden)

    Sadun Amirul Syafiq

    2017-01-01

    Full Text Available Recently, the Modbus RTU protocol has been widely accepted in the application of robotics, communications and industrial control systems due to its simplicity and reliability. With the help of the MATLAB Instrument Control Toolbox, a serial communication between Simulink and a 3 Finger Adaptive Robot Gripper can be realized to demonstrate a grasping functionality. The toolbox includes a “to instrument” and “query instrument” programming blocks that enable the users to create a serial communication with the targeted hardware/robot. Similarly, the Simulink Arduino IO package also offers a real-time feature that enabled it to act as a DAQ device. This paper establishes a real-time robot control by using Modbus RTU and Arduino IO Package for a 3 Finger Adaptive Robot Gripper. The robot communication and grasping performance were successfully implemented and demonstrated. In particular, three (3 different grasping mode via normal, wide and pinch were tested. Moreover, the robot gripper’s feedback data, such as encoder position, motor current and the grasping force were easily measured and acquired in real-time. This certainly essential for future grasping analysis of a 3 Finger Adaptive Robot Gripper.

  2. Distributed Consensus-Based Robust Adaptive Formation Control for Nonholonomic Mobile Robots with Partial Known Dynamics

    Directory of Open Access Journals (Sweden)

    Zhaoxia Peng

    2014-01-01

    Full Text Available This paper investigates the distributed consensus-based robust adaptive formation control for nonholonomic mobile robots with partially known dynamics. Firstly, multirobot formation control problem has been converted into a state consensus problem. Secondly, the practical control strategies, which incorporate the distributed kinematic controllers and the robust adaptive torque controllers, are designed for solving the formation control problem. Thirdly, the specified reference trajectory for the geometric centroid of the formation is assumed as the trajectory of a virtual leader, whose information is available to only a subset of the followers. Finally, numerical results are provided to illustrate the effectiveness of the proposed control approaches.

  3. Direct model reference adaptive control with application to flexible robots

    Science.gov (United States)

    Steinvorth, Rodrigo; Kaufman, Howard; Neat, Gregory W.

    1992-01-01

    A modification to a direct command generator tracker-based model reference adaptive control (MRAC) system is suggested in this paper. This modification incorporates a feedforward into the reference model's output as well as the plant's output. Its purpose is to eliminate the bounded model following error present in steady state when previous MRAC systems were used. The algorithm was evaluated using the dynamics for a single-link flexible-joint arm. The results of these simulations show a response with zero steady state model following error. These results encourage further use of MRAC for various types of nonlinear plants.

  4. Optimization of welding parameters using a genetic algorithm: A robotic arm–assisted implementation for recovery of Pelton turbine blades

    Directory of Open Access Journals (Sweden)

    Luis Pérez Pozo

    2015-11-01

    Full Text Available This work presents the operational optimization of a welding operation involving using genetic algorithms. The welding curves correspond to the profile of a blade-shaped Pelton turbine. The procedure involved the development of a series of tests and observation of the parameters that will be controlled during the welding process. After the tests were performed, the samples were prepared for chemical attack, which allowed observation of the penetration, weld area, and dilution. After that, mathematical models were developed that correlate the controllable welding parameters with the aforementioned bead parameters. In those mathematical models, the optimization of the process parameters was performed using genetic algorithms. Specially programmed functions for mutation, reproduction, and initialization processes were written and used in the implemented model. After the optimization process was completed, the results were evaluated through new tests to verify whether the obtained objective functions properly describe the characteristics of the weld. The comparisons showed errors of less than 6%.

  5. Self-adaptive robot training of stroke survivors for continuous tracking movements

    Directory of Open Access Journals (Sweden)

    Morasso Pietro

    2010-03-01

    Full Text Available Abstract Background Although robot therapy is progressively becoming an accepted method of treatment for stroke survivors, few studies have investigated how to adapt the robot/subject interaction forces in an automatic way. The paper is a feasibility study of a novel self-adaptive robot controller to be applied with continuous tracking movements. Methods The haptic robot Braccio di Ferro is used, in relation with a tracking task. The proposed control architecture is based on three main modules: 1 a force field generator that combines a non linear attractive field and a viscous field; 2 a performance evaluation module; 3 an adaptive controller. The first module operates in a continuous time fashion; the other two modules operate in an intermittent way and are triggered at the end of the current block of trials. The controller progressively decreases the gain of the force field, within a session, but operates in a non monotonic way between sessions: it remembers the minimum gain achieved in a session and propagates it to the next one, which starts with a block whose gain is greater than the previous one. The initial assistance gains are chosen according to a minimal assistance strategy. The scheme can also be applied with closed eyes in order to enhance the role of proprioception in learning and control. Results The preliminary results with a small group of patients (10 chronic hemiplegic subjects show that the scheme is robust and promotes a statistically significant improvement in performance indicators as well as a recalibration of the visual and proprioceptive channels. The results confirm that the minimally assistive, self-adaptive strategy is well tolerated by severely impaired subjects and is beneficial also for less severe patients. Conclusions The experiments provide detailed information about the stability and robustness of the adaptive controller of robot assistance that could be quite relevant for the design of future large scale

  6. Adaptive control of 5 DOF upper-limb exoskeleton robot with improved safety.

    Science.gov (United States)

    Kang, Hao-Bo; Wang, Jian-Hui

    2013-11-01

    This paper studies an adaptive control strategy for a class of 5 DOF upper-limb exoskeleton robot with a special safety consideration. The safety requirement plays a critical role in the clinical treatment when assisting patients with shoulder, elbow and wrist joint movements. With the objective of assuring the tracking performance of the pre-specified operations, the proposed adaptive controller is firstly designed to be robust to the model uncertainties. To further improve the safety and fault-tolerance in the presence of unknown large parameter variances or even actuator faults, the adaptive controller is on-line updated according to the information provided by an adaptive observer without additional sensors. An output tracking performance is well achieved with a tunable error bound. The experimental example also verifies the effectiveness of the proposed control scheme. © 2013 ISA. Published by ISA. All rights reserved.

  7. Adaptive control of two-wheeled mobile balance robot capable to adapt different surfaces using a novel artificial neural network–based real-time switching dynamic controller

    Directory of Open Access Journals (Sweden)

    Ali Unluturk

    2017-03-01

    Full Text Available In this article, a novel real-time artificial neural network–based adaptable switching dynamic controller is developed and practically implemented. It will be used for real-time control of two-wheeled balance robot which can balance itself upright position on different surfaces. In order to examine the efficiency of the proposed controller, a two-wheeled mobile balance robot is designed and a test platform for experimental setup is made for balance problem on different surfaces. In a developed adaptive controller algorithm which is capable to adapt different surfaces, mean absolute target angle deviation error, mean absolute target displacement deviation error and mean absolute controller output data are employed for surface estimation by using artificial neural network. In a designed two-wheeled mobile balance robot system, robot tilt angle is estimated via Kalman filter from accelerometer and gyroscope sensor signals. Furthermore, a visual robot control interface is developed in C++ software development environment so that robot controller parameters can be changed as desired. In addition, robot balance angle, linear displacement and controller output can be observed online on personal computer. According to the real-time experimental results, the proposed novel type controller gives more effective results than the classic ones.

  8. Dynamic Learning from Adaptive Neural Control of Uncertain Robots with Guaranteed Full-State Tracking Precision

    Directory of Open Access Journals (Sweden)

    Min Wang

    2017-01-01

    Full Text Available A dynamic learning method is developed for an uncertain n-link robot with unknown system dynamics, achieving predefined performance attributes on the link angular position and velocity tracking errors. For a known nonsingular initial robotic condition, performance functions and unconstrained transformation errors are employed to prevent the violation of the full-state tracking error constraints. By combining two independent Lyapunov functions and radial basis function (RBF neural network (NN approximator, a novel and simple adaptive neural control scheme is proposed for the dynamics of the unconstrained transformation errors, which guarantees uniformly ultimate boundedness of all the signals in the closed-loop system. In the steady-state control process, RBF NNs are verified to satisfy the partial persistent excitation (PE condition. Subsequently, an appropriate state transformation is adopted to achieve the accurate convergence of neural weight estimates. The corresponding experienced knowledge on unknown robotic dynamics is stored in NNs with constant neural weight values. Using the stored knowledge, a static neural learning controller is developed to improve the full-state tracking performance. A comparative simulation study on a 2-link robot illustrates the effectiveness of the proposed scheme.

  9. Adaptation of a haptic robot in a 3T fMRI.

    Science.gov (United States)

    Snider, Joseph; Plank, Markus; May, Larry; Liu, Thomas T; Poizner, Howard

    2011-10-04

    Functional magnetic resonance imaging (fMRI) provides excellent functional brain imaging via the BOLD signal with advantages including non-ionizing radiation, millimeter spatial accuracy of anatomical and functional data, and nearly real-time analyses. Haptic robots provide precise measurement and control of position and force of a cursor in a reasonably confined space. Here we combine these two technologies to allow precision experiments involving motor control with haptic/tactile environment interaction such as reaching or grasping. The basic idea is to attach an 8 foot end effecter supported in the center to the robot allowing the subject to use the robot, but shielding it and keeping it out of the most extreme part of the magnetic field from the fMRI machine (Figure 1). The Phantom Premium 3.0, 6DoF, high-force robot (SensAble Technologies, Inc.) is an excellent choice for providing force-feedback in virtual reality experiments, but it is inherently non-MR safe, introduces significant noise to the sensitive fMRI equipment, and its electric motors may be affected by the fMRI's strongly varying magnetic field. We have constructed a table and shielding system that allows the robot to be safely introduced into the fMRI environment and limits both the degradation of the fMRI signal by the electrically noisy motors and the degradation of the electric motor performance by the strongly varying magnetic field of the fMRI. With the shield, the signal to noise ratio (SNR: mean signal/noise standard deviation) of the fMRI goes from a baseline of ~380 to ~330, and ~250 without the shielding. The remaining noise appears to be uncorrelated and does not add artifacts to the fMRI of a test sphere (Figure 2). The long, stiff handle allows placement of the robot out of range of the most strongly varying parts of the magnetic field so there is no significant effect of the fMRI on the robot. The effect of the handle on the robot's kinematics is minimal since it is lightweight (~2

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

    Directory of Open Access Journals (Sweden)

    Chunfu Wu

    2015-01-01

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

  11. Neuromechanical adaptations during a robotic powered exoskeleton assisted walking session.

    Science.gov (United States)

    Ramanujam, Arvind; Cirnigliaro, Christopher M; Garbarini, Erica; Asselin, Pierre; Pilkar, Rakesh; Forrest, Gail F

    2017-04-20

    To evaluate gait parameters and neuromuscular profiles of exoskeleton-assisted walking under Max Assist condition during a single-session for; (i) able bodied (AB) individuals walking assisted with (EXO) and without (non-EXO) a powered exoskeleton, (ii) non-ambulatory SCI individuals walking assisted with a powered exoskeleton. Single-session. Motion analysis laboratory. Four AB individuals and four individuals with SCI. Powered lower extremity exoskeleton. Temporal-spatial parameters, kinematics, walking velocity and electromyography data. AB individuals in exoskeleton showed greater stance time and a significant reduction in walking velocity (P exoskeleton movements, they walked with an increased velocity and lowered stance time to resemble that of slow walking. For SCI individuals, mean percent stance time was higher and walking velocity was lower compared to all AB walking conditions (P exoskeleton and moreover with voluntary control there is a greater temporal-spatial response of the lower limbs. Also, there are neuromuscular phasic adaptions for both AB and SCI groups while walking in the exoskeleton that are inconsistent to non-EXO gait muscle activation.

  12. Enhancing Perception with Tactile Object Recognition in Adaptive Grippers for Human–Robot Interaction

    Directory of Open Access Journals (Sweden)

    Juan M. Gandarias

    2018-02-01

    Full Text Available The use of tactile perception can help first response robotic teams in disaster scenarios, where visibility conditions are often reduced due to the presence of dust, mud, or smoke, distinguishing human limbs from other objects with similar shapes. Here, the integration of the tactile sensor in adaptive grippers is evaluated, measuring the performance of an object recognition task based on deep convolutional neural networks (DCNNs using a flexible sensor mounted in adaptive grippers. A total of 15 classes with 50 tactile images each were trained, including human body parts and common environment objects, in semi-rigid and flexible adaptive grippers based on the fin ray effect. The classifier was compared against the rigid configuration and a support vector machine classifier (SVM. Finally, a two-level output network has been proposed to provide both object-type recognition and human/non-human classification. Sensors in adaptive grippers have a higher number of non-null tactels (up to 37% more, with a lower mean of pressure values (up to 72% less than when using a rigid sensor, with a softer grip, which is needed in physical human–robot interaction (pHRI. A semi-rigid implementation with 95.13% object recognition rate was chosen, even though the human/non-human classification had better results (98.78% with a rigid sensor.

  13. Enhancing Perception with Tactile Object Recognition in Adaptive Grippers for Human-Robot Interaction.

    Science.gov (United States)

    Gandarias, Juan M; Gómez-de-Gabriel, Jesús M; García-Cerezo, Alfonso J

    2018-02-26

    The use of tactile perception can help first response robotic teams in disaster scenarios, where visibility conditions are often reduced due to the presence of dust, mud, or smoke, distinguishing human limbs from other objects with similar shapes. Here, the integration of the tactile sensor in adaptive grippers is evaluated, measuring the performance of an object recognition task based on deep convolutional neural networks (DCNNs) using a flexible sensor mounted in adaptive grippers. A total of 15 classes with 50 tactile images each were trained, including human body parts and common environment objects, in semi-rigid and flexible adaptive grippers based on the fin ray effect. The classifier was compared against the rigid configuration and a support vector machine classifier (SVM). Finally, a two-level output network has been proposed to provide both object-type recognition and human/non-human classification. Sensors in adaptive grippers have a higher number of non-null tactels (up to 37% more), with a lower mean of pressure values (up to 72% less) than when using a rigid sensor, with a softer grip, which is needed in physical human-robot interaction (pHRI). A semi-rigid implementation with 95.13% object recognition rate was chosen, even though the human/non-human classification had better results (98.78%) with a rigid sensor.

  14. Adaptive Tracking and Obstacle Avoidance Control for Mobile Robots with Unknown Sliding

    Directory of Open Access Journals (Sweden)

    Mingyue Cui

    2012-11-01

    Full Text Available An adaptive control approach is proposed for trajectory tracking and obstacle avoidance for mobile robots with consideration given to unknown sliding. A kinematic model of mobile robots is established in this paper, in which both longitudinal and lateral sliding are considered and processed as three time-varying parameters. A sliding model observer is introduced to estimate the sliding parameters online. A stable tracking control law for this nonholonomic system is proposed to compensate the unknown sliding effect. From Lyapunov-stability analysis, it is proved, regardless of unknown sliding, that tracking errors of the controlled closed-loop system are asymptotically stable, the tracking errors converge to zero outside the obstacle detection region and obstacle avoidance is guaranteed inside the obstacle detection region. The efficiency and robustness of the proposed control system are verified by simulation results.

  15. Weld-bonding: a very well adapted joining technique to decrease the weight of steel structures; Le soudo-collage: une technique d'assemblage performante pour alleger les structures en acier

    Energy Technology Data Exchange (ETDEWEB)

    Charbonnet, Ph.; Clad, A.; Di Fant-Jaeckels, H.; Thirion, J.L. [Usinor RD, 92 - Puteaux (France)

    2000-04-01

    The association of spot welding and adhesive bonding, named weld-bonding, is a steel joining technique which increasingly interests car manufacturers. Nevertheless, weld-bonding is not at present used extensively by them due to a lack of data related to the performance of this technique. Studies carried out by Usinor have succeeded in demonstrating that weld-bonding is a very well adapted joining technique to decrease the weight of steel structures. (author)

  16. A neural learning classifier system with self-adaptive constructivism for mobile robot control.

    Science.gov (United States)

    Hurst, Jacob; Bull, Larry

    2006-01-01

    For artificial entities to achieve true autonomy and display complex lifelike behavior, they will need to exploit appropriate adaptable learning algorithms. In this context adaptability implies flexibility guided by the environment at any given time and an open-ended ability to learn appropriate behaviors. This article examines the use of constructivism-inspired mechanisms within a neural learning classifier system architecture that exploits parameter self-adaptation as an approach to realize such behavior. The system uses a rule structure in which each rule is represented by an artificial neural network. It is shown that appropriate internal rule complexity emerges during learning at a rate controlled by the learner and that the structure indicates underlying features of the task. Results are presented in simulated mazes before moving to a mobile robot platform.

  17. Adaptive Shape Kernel-Based Mean Shift Tracker in Robot Vision System

    Directory of Open Access Journals (Sweden)

    Chunmei Liu

    2016-01-01

    Full Text Available This paper proposes an adaptive shape kernel-based mean shift tracker using a single static camera for the robot vision system. The question that we address in this paper is how to construct such a kernel shape that is adaptive to the object shape. We perform nonlinear manifold learning technique to obtain the low-dimensional shape space which is trained by training data with the same view as the tracking video. The proposed kernel searches the shape in the low-dimensional shape space obtained by nonlinear manifold learning technique and constructs the adaptive kernel shape in the high-dimensional shape space. It can improve mean shift tracker performance to track object position and object contour and avoid the background clutter. In the experimental part, we take the walking human as example to validate that our method is accurate and robust to track human position and describe human contour.

  18. Adaptive Shape Kernel-Based Mean Shift Tracker in Robot Vision System

    Science.gov (United States)

    2016-01-01

    This paper proposes an adaptive shape kernel-based mean shift tracker using a single static camera for the robot vision system. The question that we address in this paper is how to construct such a kernel shape that is adaptive to the object shape. We perform nonlinear manifold learning technique to obtain the low-dimensional shape space which is trained by training data with the same view as the tracking video. The proposed kernel searches the shape in the low-dimensional shape space obtained by nonlinear manifold learning technique and constructs the adaptive kernel shape in the high-dimensional shape space. It can improve mean shift tracker performance to track object position and object contour and avoid the background clutter. In the experimental part, we take the walking human as example to validate that our method is accurate and robust to track human position and describe human contour. PMID:27379165

  19. Adaptive Control for Autonomous Navigation of Mobile Robots Considering Time Delay and Uncertainty

    Science.gov (United States)

    Armah, Stephen Kofi

    Autonomous control of mobile robots has attracted considerable attention of researchers in the areas of robotics and autonomous systems during the past decades. One of the goals in the field of mobile robotics is development of platforms that robustly operate in given, partially unknown, or unpredictable environments and offer desired services to humans. Autonomous mobile robots need to be equipped with effective, robust and/or adaptive, navigation control systems. In spite of enormous reported work on autonomous navigation control systems for mobile robots, achieving the goal above is still an open problem. Robustness and reliability of the controlled system can always be improved. The fundamental issues affecting the stability of the control systems include the undesired nonlinear effects introduced by actuator saturation, time delay in the controlled system, and uncertainty in the model. This research work develops robustly stabilizing control systems by investigating and addressing such nonlinear effects through analytical, simulations, and experiments. The control systems are designed to meet specified transient and steady-state specifications. The systems used for this research are ground (Dr Robot X80SV) and aerial (Parrot AR.Drone 2.0) mobile robots. Firstly, an effective autonomous navigation control system is developed for X80SV using logic control by combining 'go-to-goal', 'avoid-obstacle', and 'follow-wall' controllers. A MATLAB robot simulator is developed to implement this control algorithm and experiments are conducted in a typical office environment. The next stage of the research develops an autonomous position (x, y, and z) and attitude (roll, pitch, and yaw) controllers for a quadrotor, and PD-feedback control is used to achieve stabilization. The quadrotor's nonlinear dynamics and kinematics are implemented using MATLAB S-function to generate the state output. Secondly, the white-box and black-box approaches are used to obtain a linearized

  20. Learning to walk with an adaptive gain proportional myoelectric controller for a robotic ankle exoskeleton.

    Science.gov (United States)

    Koller, Jeffrey R; Jacobs, Daniel A; Ferris, Daniel P; Remy, C David

    2015-11-04

    Robotic ankle exoskeletons can provide assistance to users and reduce metabolic power during walking. Our research group has investigated the use of proportional myoelectric control for controlling robotic ankle exoskeletons. Previously, these controllers have relied on a constant gain to map user's muscle activity to actuation control signals. A constant gain may act as a constraint on the user, so we designed a controller that dynamically adapts the gain to the user's myoelectric amplitude. We hypothesized that an adaptive gain proportional myoelectric controller would reduce metabolic energy expenditure compared to walking with the ankle exoskeleton unpowered because users could choose their preferred control gain. We tested eight healthy subjects walking with the adaptive gain proportional myoelectric controller with bilateral ankle exoskeletons. The adaptive gain was updated each stride such that on average the user's peak muscle activity was mapped to maximal power output of the exoskeleton. All subjects participated in three identical training sessions where they walked on a treadmill for 50 minutes (30 minutes of which the exoskeleton was powered) at 1.2 ms(-1). We calculated and analyzed metabolic energy consumption, muscle recruitment, inverse kinematics, inverse dynamics, and exoskeleton mechanics. Using our controller, subjects achieved a metabolic reduction similar to that seen in previous work in about a third of the training time. The resulting controller gain was lower than that seen in previous work (β=1.50±0.14 versus a constant β=2). The adapted gain allowed users more total ankle joint power than that of unassisted walking, increasing ankle power in exchange for a decrease in hip power. Our findings indicate that humans prefer to walk with greater ankle mechanical power output than their unassisted gait when provided with an ankle exoskeleton using an adaptive controller. This suggests that robotic assistance from an exoskeleton can allow

  1. Robo-AO KP: A new era in robotic adaptive optics

    Science.gov (United States)

    Riddle, Reed L.; Baranec, Christoph; Law, Nicholas M.; Kulkarni, Shrinivas R.; Duev, Dmitry; Ziegler, Carl; Jensen-Clem, Rebecca M.; Atkinson, Dani Eleanor; Tanner, Angelle M.; Zhang, Celia; Ray, Amy

    2016-01-01

    Robo-AO is the first and only fully automated adaptive optics laser guide star AO instrument. It was developed as an instrument for 1-3m robotic telescopes, in order to take advantage of their availability to pursue large survey programs and target of opportunity observations that aren't possible with other AO systems. Robo-AO is currently the most efficient AO system in existence, and it can achieve an observation rate of 20+ science targets per hour. In more than three years of operations at Palomar Observatory, it has been quite successful, producing technology that is being adapted by other AO systems and robotic telescope projects, as well as several high impact scientific publications. Now, Robo-AO has been selected to take over operation of the Kitt Peak National Observatory 2.1m telescope. This will give Robo-AO KP the opportunity to pursue multiple science programs consisting of several thousand targets each during the three years it will be on the telescope. One-sixth of the observing time will be allocated to the US community through the NOAO TAC process. This presentation will discuss the process adapting Robo-AO to the KPNO 2.1m telescope, the plans for integration and initial operations, and the science operations and programs to be pursued.

  2. Testing Biological Hypotheses with Embodied Robots: Adaptations, Accidents, and By-Products in the Evolution of Vertebrates

    OpenAIRE

    Roberts, Sonia F.; Hirokawa, Jonathan; Rosenblum, Hannah G.; Sakhtah, Hassan; Gutierrez, Andres A.; Porter, Marianne E.; Long, John H.

    2014-01-01

    Evolutionary robotics allows biologists to test hypotheses about extinct animals. In our case, we modeled some of the first vertebrates, jawless fishes, in order to study the evolution of the trait after which vertebrates are named: vertebrae. We tested the hypothesis that vertebrae are an adaptation for enhanced feeding and fleeing performance. We created a population of autonomous embodied robots, Preyro, in which the number of vertebrae, N, were free to evolve. In addition, two other trait...

  3. An Adaptive Web-Based Support to e-Education in Robotics and Automation

    Science.gov (United States)

    di Giamberardino, Paolo; Temperini, Marco

    The paper presents the hardware and software architecture of a remote laboratory, with robotics and automation applications, devised to support e-teaching and e-learning activities, at an undergraduate level in computer engineering. The hardware is composed by modular structures, based on the Lego Mindstorms components: they are reasonably sophisticated in terms of functions, pretty easy to use, and sufficiently affordable in terms of cost. Moreover, being the robots intrinsically modular, wrt the number and distribution of sensors and actuators, they are easily and quickly reconfigurable. A web application makes the laboratory and its robots available via internet. The software framework allows the teacher to define, for the course under her/his responsibility, a learning path made of different and differently complex exercises, graduated in terms of the "difficulty" they require to meet and of the "competence" that the solver is supposed to have shown. The learning path of exercises is adapted to the individual learner's progressively growing competence: at any moment, only a subset of the exercises is available (depending on how close their levels of competence and difficulty are to those of the exercises already solved by the learner).

  4. Novel Adaptive Forward Neural MIMO NARX Model for the Identification of Industrial 3-DOF Robot Arm Kinematics

    Directory of Open Access Journals (Sweden)

    Ho Pham Huy Anh

    2012-10-01

    Full Text Available In this paper, a novel forward adaptive neural MIMO NARX model is used for modelling and identifying the forward kinematics of an industrial 3-DOF robot arm system. The nonlinear features of the forward kinematics of the industrial robot arm drive are thoroughly modelled based on the forward adaptive neural NARX model-based identification process using experimental input-output training data. This paper proposes a novel use of a back propagation (BP algorithm to generate the forward neural MIMO NARX (FNMN model for the forward kinematics of the industrial 3-DOF robot arm. The results show that the proposed adaptive neural NARX model trained by a Back Propagation learning algorithm yields outstanding performance and perfect accuracy.

  5. Robotics

    Indian Academy of Sciences (India)

    netic induction to detect an object. The development of ... end effector, inclination of object, magnetic and electric fields, etc. The sensors described ... In the case of a robot, the various actuators and motors have to be modelled. The major ...

  6. Synaptic plasticity in a recurrent neural network for versatile and adaptive behaviors of a walking robot

    DEFF Research Database (Denmark)

    Grinke, Eduard; Tetzlaff, Christian; Wörgötter, Florentin

    2015-01-01

    correlation-based learning with synaptic scaling is applied to adequately change the connections of the network. By doing so, we can effectively exploit neural dynamics (i.e., hysteresis effects and single attractors) in the network to generate different turning angles with short-term memory for a walking...... dynamics, plasticity, sensory feedback, and biomechanics. Generating such versatile and adaptive behaviors for a many degrees-of-freedom (DOFs) walking robot is a challenging task. Thus, in this study, we present a bio-inspired approach to solve this task. Specifically, the approach combines neural...... mechanisms with plasticity, exteroceptive sensory feedback, and biomechanics. The neural mechanisms consist of adaptive neural sensory processing and modular neural locomotion control. The sensory processing is based on a small recurrent neural network consisting of two fully connected neurons. Online...

  7. Robust controller with adaptation within the boundary layer: application to nuclear underwater inspection robot

    International Nuclear Information System (INIS)

    Park, Gee Yong; Yoon, Ji Sup; Hong, Dong Hee; Jeong, Jae Hoo

    2002-01-01

    In this paper, the robust control scheme with the improved control performance within the boundary layer is proposed. In the control scheme, the robust controller based on the traditional variable structure control method is modified to have the adaptation within the boundary layer. From this controller, the width of the boundary layer where the robust control input is smoothened out can be given by an appropriate value. But the improve control performance within the boundary layer can be achieved without the so-called control chattering because the role of adaptive control is to compensate for the uncovered portions of the robust control occurred from the continuous approximation within the boundary layer. Simulation tests for circular navigation of an underwater wall-ranging robot developed for inspection of wall surfaces in the research reactor, TRIGA MARK III, confirm the performance improvement

  8. Adaptive Control of Exoskeleton Robots for Periodic Assistive Behaviours Based on EMG Feedback Minimisation

    Science.gov (United States)

    Peternel, Luka; Noda, Tomoyuki; Petrič, Tadej; Ude, Aleš; Morimoto, Jun; Babič, Jan

    2016-01-01

    In this paper we propose an exoskeleton control method for adaptive learning of assistive joint torque profiles in periodic tasks. We use human muscle activity as feedback to adapt the assistive joint torque behaviour in a way that the muscle activity is minimised. The user can then relax while the exoskeleton takes over the task execution. If the task is altered and the existing assistive behaviour becomes inadequate, the exoskeleton gradually adapts to the new task execution so that the increased muscle activity caused by the new desired task can be reduced. The advantage of the proposed method is that it does not require biomechanical or dynamical models. Our proposed learning system uses Dynamical Movement Primitives (DMPs) as a trajectory generator and parameters of DMPs are modulated using Locally Weighted Regression. Then, the learning system is combined with adaptive oscillators that determine the phase and frequency of motion according to measured Electromyography (EMG) signals. We tested the method with real robot experiments where subjects wearing an elbow exoskeleton had to move an object of an unknown mass according to a predefined reference motion. We further evaluated the proposed approach on a whole-arm exoskeleton to show that it is able to adaptively derive assistive torques even for multiple-joint motion. PMID:26881743

  9. Adaptive Control of Exoskeleton Robots for Periodic Assistive Behaviours Based on EMG Feedback Minimisation.

    Science.gov (United States)

    Peternel, Luka; Noda, Tomoyuki; Petrič, Tadej; Ude, Aleš; Morimoto, Jun; Babič, Jan

    2016-01-01

    In this paper we propose an exoskeleton control method for adaptive learning of assistive joint torque profiles in periodic tasks. We use human muscle activity as feedback to adapt the assistive joint torque behaviour in a way that the muscle activity is minimised. The user can then relax while the exoskeleton takes over the task execution. If the task is altered and the existing assistive behaviour becomes inadequate, the exoskeleton gradually adapts to the new task execution so that the increased muscle activity caused by the new desired task can be reduced. The advantage of the proposed method is that it does not require biomechanical or dynamical models. Our proposed learning system uses Dynamical Movement Primitives (DMPs) as a trajectory generator and parameters of DMPs are modulated using Locally Weighted Regression. Then, the learning system is combined with adaptive oscillators that determine the phase and frequency of motion according to measured Electromyography (EMG) signals. We tested the method with real robot experiments where subjects wearing an elbow exoskeleton had to move an object of an unknown mass according to a predefined reference motion. We further evaluated the proposed approach on a whole-arm exoskeleton to show that it is able to adaptively derive assistive torques even for multiple-joint motion.

  10. Adaptive Control of Exoskeleton Robots for Periodic Assistive Behaviours Based on EMG Feedback Minimisation.

    Directory of Open Access Journals (Sweden)

    Luka Peternel

    Full Text Available In this paper we propose an exoskeleton control method for adaptive learning of assistive joint torque profiles in periodic tasks. We use human muscle activity as feedback to adapt the assistive joint torque behaviour in a way that the muscle activity is minimised. The user can then relax while the exoskeleton takes over the task execution. If the task is altered and the existing assistive behaviour becomes inadequate, the exoskeleton gradually adapts to the new task execution so that the increased muscle activity caused by the new desired task can be reduced. The advantage of the proposed method is that it does not require biomechanical or dynamical models. Our proposed learning system uses Dynamical Movement Primitives (DMPs as a trajectory generator and parameters of DMPs are modulated using Locally Weighted Regression. Then, the learning system is combined with adaptive oscillators that determine the phase and frequency of motion according to measured Electromyography (EMG signals. We tested the method with real robot experiments where subjects wearing an elbow exoskeleton had to move an object of an unknown mass according to a predefined reference motion. We further evaluated the proposed approach on a whole-arm exoskeleton to show that it is able to adaptively derive assistive torques even for multiple-joint motion.

  11. Cerebellar-inspired adaptive control of a robot eye actuated by pneumatic artificial muscles.

    Science.gov (United States)

    Lenz, Alexander; Anderson, Sean R; Pipe, A G; Melhuish, Chris; Dean, Paul; Porrill, John

    2009-12-01

    In this paper, a model of cerebellar function is implemented and evaluated in the control of a robot eye actuated by pneumatic artificial muscles. The investigated control problem is stabilization of the visual image in response to disturbances. This is analogous to the vestibuloocular reflex (VOR) in humans. The cerebellar model is structurally based on the adaptive filter, and the learning rule is computationally analogous to least-mean squares, where parameter adaptation at the parallel fiber/Purkinje cell synapse is driven by the correlation of the sensory error signal (carried by the climbing fiber) and the motor command signal. Convergence of the algorithm is first analyzed in simulation on a model of the robot and then tested online in both one and two degrees of freedom. The results show that this model of neural function successfully works on a real-world problem, providing empirical evidence for validating: 1) the generic cerebellar learning algorithm; 2) the function of the cerebellum in the VOR; and 3) the signal transmission between functional neural components of the VOR.

  12. Heart Motion Prediction in Robotic-Assisted Beating Heart Surgery: A Nonlinear Fast Adaptive Approach

    Directory of Open Access Journals (Sweden)

    Fan Liang

    2013-01-01

    Full Text Available Off-pump Coronary Artery Bypass Graft (CABG surgery outperforms traditional on-pump surgery because the assisted robotic tools can alleviate the relative motion between the beating heart and robotic tools. Therefore, it is possible for the surgeon to operate on the beating heart and thus lessens post surgery complications for the patients. Due to the highly irregular and non-stationary nature of heart motion, it is critical that the beating heart motion is predicted in the model-based track control procedures. It is technically preferable to model heart motion in a nonlinear way because the characteristic analysis of 3D heart motion data through Bi-spectral analysis and Fourier methods demonstrates the involved nonlinearity of heart motion. We propose an adaptive nonlinear heart motion model based on the Volterra Series in this paper. We also design a fast lattice structure to achieve computational-efficiency for real-time online predictions. We argue that the quadratic term of the Volterra Series can improve the prediction accuracy by covering sharp change points and including the motion with sufficient detail. The experiment results indicate that the adaptive nonlinear heart motion prediction algorithm outperforms the autoregressive (AR and the time-varying Fourier-series models in terms of the root mean square of the prediction error and the prediction error in extreme cases.

  13. A Novel Low-Cost Adaptive Scanner Concept for Mobile Robots

    Directory of Open Access Journals (Sweden)

    Ivo Stančić

    2014-09-01

    Full Text Available A fundamental problem in mobile robot applications is the need for accurate knowledge of the position of a vehicle for localizing itself and for avoiding obstacles in its path. In the search for a solution to this problem, researchers and engineers have developed different sensors, systems and techniques. Modern mobile robots relay information obtained from a variety of sensors and sophisticated data fusion algorithms. In this paper, a novel concept for a low-cost adaptive scanner based on a projected light pattern is proposed. The main advantage of the proposed system is its adaptivity, which enables the rapid scanning of the robot’s surroundings in search of obstacles and a more detailed scan of a single object to retrieve its surface configuration and perform some limited analyses. This paper addresses the concept behind such a scanner, where a proof-of-concept is achieved using an office DLP projector. During the measurements, the accuracy of the proposed system was tested on obstacles and objects with known configurations. The obtained results are presented and analyzed, and conclusions about the system’s performance and possible improvements are discussed.

  14. SIMULATION OF ADAPTIVE BEHAVIOR IN THE CONTEXT OF SOLVING AN AUTONOMOUS ROBOTIC VEHICLE MOTION TASK ON TWO-DIMENSIONAL PLANE WITH OBSTACLES

    Directory of Open Access Journals (Sweden)

    R. A. Prakapovich

    2014-01-01

    Full Text Available An adaptive neurocontroller for autonomous robotic vehicle control, which is designed to generate control signals (according to preprogrammed motion algorithm and to develop individual reactions to some external impacts during functioning process, that allows the robot to adapt to external environment changes, is suggested. To debug and test the proposed neurocontroller a specially designed program, able to simulate the sensory and executive systems operation of the robotic vehicle, is used.

  15. Disturbance-Estimated Adaptive Backstepping Sliding Mode Control of a Pneumatic Muscles-Driven Ankle Rehabilitation Robot

    Directory of Open Access Journals (Sweden)

    Qingsong Ai

    2017-12-01

    Full Text Available A rehabilitation robot plays an important role in relieving the therapists’ burden and helping patients with ankle injuries to perform more accurate and effective rehabilitation training. However, a majority of current ankle rehabilitation robots are rigid and have drawbacks in terms of complex structure, poor flexibility and lack of safety. Taking advantages of pneumatic muscles’ good flexibility and light weight, we developed a novel two degrees of freedom (2-DOF parallel compliant ankle rehabilitation robot actuated by pneumatic muscles (PMs. To solve the PM’s nonlinear characteristics during operation and to tackle the human-robot uncertainties in rehabilitation, an adaptive backstepping sliding mode control (ABS-SMC method is proposed in this paper. The human-robot external disturbance can be estimated by an observer, who is then used to adjust the robot output to accommodate external changes. The system stability is guaranteed by the Lyapunov stability theorem. Experimental results on the compliant ankle rehabilitation robot show that the proposed ABS-SMC is able to estimate the external disturbance online and adjust the control output in real time during operation, resulting in a higher trajectory tracking accuracy and better response performance especially in dynamic conditions.

  16. Disturbance-Estimated Adaptive Backstepping Sliding Mode Control of a Pneumatic Muscles-Driven Ankle Rehabilitation Robot.

    Science.gov (United States)

    Ai, Qingsong; Zhu, Chengxiang; Zuo, Jie; Meng, Wei; Liu, Quan; Xie, Sheng Q; Yang, Ming

    2017-12-28

    A rehabilitation robot plays an important role in relieving the therapists' burden and helping patients with ankle injuries to perform more accurate and effective rehabilitation training. However, a majority of current ankle rehabilitation robots are rigid and have drawbacks in terms of complex structure, poor flexibility and lack of safety. Taking advantages of pneumatic muscles' good flexibility and light weight, we developed a novel two degrees of freedom (2-DOF) parallel compliant ankle rehabilitation robot actuated by pneumatic muscles (PMs). To solve the PM's nonlinear characteristics during operation and to tackle the human-robot uncertainties in rehabilitation, an adaptive backstepping sliding mode control (ABS-SMC) method is proposed in this paper. The human-robot external disturbance can be estimated by an observer, who is then used to adjust the robot output to accommodate external changes. The system stability is guaranteed by the Lyapunov stability theorem. Experimental results on the compliant ankle rehabilitation robot show that the proposed ABS-SMC is able to estimate the external disturbance online and adjust the control output in real time during operation, resulting in a higher trajectory tracking accuracy and better response performance especially in dynamic conditions.

  17. Automatic monitoring of vibration welding equipment

    Science.gov (United States)

    Spicer, John Patrick; Chakraborty, Debejyo; Wincek, Michael Anthony; Wang, Hui; Abell, Jeffrey A; Bracey, Jennifer; Cai, Wayne W

    2014-10-14

    A vibration welding system includes vibration welding equipment having a welding horn and anvil, a host device, a check station, and a robot. The robot moves the horn and anvil via an arm to the check station. Sensors, e.g., temperature sensors, are positioned with respect to the welding equipment. Additional sensors are positioned with respect to the check station, including a pressure-sensitive array. The host device, which monitors a condition of the welding equipment, measures signals via the sensors positioned with respect to the welding equipment when the horn is actively forming a weld. The robot moves the horn and anvil to the check station, activates the check station sensors at the check station, and determines a condition of the welding equipment by processing the received signals. Acoustic, force, temperature, displacement, amplitude, and/or attitude/gyroscopic sensors may be used.

  18. Design and Experimental Development of a Pneumatic Stiffness Adjustable Foot System for Biped Robots Adaptable to Bumps on the Ground

    Directory of Open Access Journals (Sweden)

    Xizhe Zang

    2017-09-01

    Full Text Available Walking on rough terrains still remains a challenge that needs to be addressed for biped robots because the unevenness on the ground can easily disrupt the walking stability. This paper proposes a novel foot system with passively adjustable stiffness for biped robots which is adaptable to small-sized bumps on the ground. The robotic foot is developed by attaching eight pneumatic variable stiffness units to the sole separately and symmetrically. Each variable stiffness unit mainly consists of a pneumatic bladder and a mechanical reversing valve. When walking on rough ground, the pneumatic bladders in contact with bumps are compressed, and the corresponding reversing valves are triggered to expel out the air, enabling the pneumatic bladders to adapt to the bumps with low stiffness; while the other pneumatic bladders remain rigid and maintain stable contact with the ground, providing support to the biped robot. The performances of the proposed foot system, including the variable stiffness mechanism, the adaptability on the bumps of different heights, and the application on a biped robot prototype are demonstrated by various experiments.

  19. Handbook of Plastic Welding

    DEFF Research Database (Denmark)

    Islam, Aminul

    The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve...

  20. In situ post-weld heat treatment on martensitic stainless steel turbine runners using a robotic induction heating process to control temperature distribution

    Science.gov (United States)

    Boudreault, E.; Hazel, B.; Côté, J.; Godin, S.

    2014-03-01

    A new robotic heat treatment process is developed. Using this solution it is now possible to perform local heat treatment on large steel components. Crack, cavitation and erosion repairs on turbine blades and Pelton buckets are among the applications of this technique. The proof of concept is made on a 13Cr-4Ni stainless steel designated "CA6NM". This alloy is widely used in the power industry for modern system components. Given the very tight temperature tolerance (600 to 630 °C) for post-weld heat treatment on this alloy, 13Cr-4Ni stainless steel is very well suited for demonstrating the possibilities of this process. To achieve heat treatment requirements, an induction heating system is mounted on a compact manipulator named "Scompi". This robot moves a pancake coil in order to control the temperature distribution. A simulator using thermal finite element analysis is first used for path planning. A feedback loop adjusts parameters in function of environmental conditions.

  1. In situ post-weld heat treatment on martensitic stainless steel turbine runners using a robotic induction heating process to control temperature distribution

    International Nuclear Information System (INIS)

    Boudreault, E; Hazel, B; Côté, J; Godin, S

    2014-01-01

    A new robotic heat treatment process is developed. Using this solution it is now possible to perform local heat treatment on large steel components. Crack, cavitation and erosion repairs on turbine blades and Pelton buckets are among the applications of this technique. The proof of concept is made on a 13Cr-4Ni stainless steel designated C A6NM . This alloy is widely used in the power industry for modern system components. Given the very tight temperature tolerance (600 to 630 °C) for post-weld heat treatment on this alloy, 13Cr-4Ni stainless steel is very well suited for demonstrating the possibilities of this process. To achieve heat treatment requirements, an induction heating system is mounted on a compact manipulator named S compi . This robot moves a pancake coil in order to control the temperature distribution. A simulator using thermal finite element analysis is first used for path planning. A feedback loop adjusts parameters in function of environmental conditions

  2. Adaptive locomotor training on an end-effector gait robot: evaluation of the ground reaction forces in different training conditions.

    Science.gov (United States)

    Tomelleri, Christopher; Waldner, Andreas; Werner, Cordula; Hesse, Stefan

    2011-01-01

    The main goal of robotic gait rehabilitation is the restoration of independent gait. To achieve this goal different and specific patterns have to be practiced intensively in order to stimulate the learning process of the central nervous system. The gait robot G-EO Systems was designed to allow the repetitive practice of floor walking, stair climbing and stair descending. A novel control strategy allows training in adaptive mode. The force interactions between the foot and the ground were analyzed on 8 healthy volunteers in three different conditions: real floor walking on a treadmill, floor walking on the gait robot in passive mode, floor walking on the gait robot in adaptive mode. The ground reaction forces were measured by a Computer Dyno Graphy (CDG) analysis system. The results show different intensities of the ground reaction force across all of the three conditions. The intensities of force interactions during the adaptive training mode are comparable to the real walking on the treadmill. Slight deviations still occur in regard to the timing pattern of the forces. The adaptive control strategy comes closer to the physiological swing phase than the passive mode and seems to be a promising option for the treatment of gait disorders. Clinical trials will validate the efficacy of this new option in locomotor therapy on the patients. © 2011 IEEE

  3. Model reference adaptive control of flexible robots in the presence of sudden load changes

    Science.gov (United States)

    Steinvorth, Rodrigo; Kaufman, Howard; Neat, Gregory

    1991-01-01

    Direct command generator tracker based model reference adaptive control (MRAC) algorithms are applied to the dynamics for a flexible-joint arm in the presence of sudden load changes. Because of the need to satisfy a positive real condition, such MRAC procedures are designed so that a feedforward augmented output follows the reference model output, thus, resulting in an ultimately bounded rather than zero output error. Thus, modifications are suggested and tested that: (1) incorporate feedforward into the reference model's output as well as the plant's output, and (2) incorporate a derivative term into only the process feedforward loop. The results of these simulations give a response with zero steady state model following error, and thus encourage further use of MRAC for more complex flexibile robotic systems.

  4. An adaptive unscented Kalman filter-based adaptive tracking control for wheeled mobile robots with control constrains in the presence of wheel slipping

    Directory of Open Access Journals (Sweden)

    Mingyue Cui

    2016-09-01

    Full Text Available A novel control approach is proposed for trajectory tracking of a wheeled mobile robot with unknown wheels’ slipping. The longitudinal and lateral slipping are considered and processed as three time-varying parameters. The adaptive unscented Kalman filter is then designed to estimate the slipping parameters online, an adaptive adjustment of the noise covariances in the estimation process is implemented using a technique of covariance matching in the adaptive unscented Kalman filter context. Considering the practical physical constrains, a stable tracking control law for this robot system is proposed by the backstepping method. Asymptotic stability is guaranteed by Lyapunov stability theory. Control gains are determined online by applying pole placement method. Simulation and real experiment results show the effectiveness and robustness of the proposed control method.

  5. Goal-recognition-based adaptive brain-computer interface for navigating immersive robotic systems

    Science.gov (United States)

    Abu-Alqumsan, Mohammad; Ebert, Felix; Peer, Angelika

    2017-06-01

    Objective. This work proposes principled strategies for self-adaptations in EEG-based Brain-computer interfaces (BCIs) as a way out of the bandwidth bottleneck resulting from the considerable mismatch between the low-bandwidth interface and the bandwidth-hungry application, and a way to enable fluent and intuitive interaction in embodiment systems. The main focus is laid upon inferring the hidden target goals of users while navigating in a remote environment as a basis for possible adaptations. Approach. To reason about possible user goals, a general user-agnostic Bayesian update rule is devised to be recursively applied upon the arrival of evidences, i.e. user input and user gaze. Experiments were conducted with healthy subjects within robotic embodiment settings to evaluate the proposed method. These experiments varied along three factors: the type of the robot/environment (simulated and physical), the type of the interface (keyboard or BCI), and the way goal recognition (GR) is used to guide a simple shared control (SC) driving scheme. Main results. Our results show that the proposed GR algorithm is able to track and infer the hidden user goals with relatively high precision and recall. Further, the realized SC driving scheme benefits from the output of the GR system and is able to reduce the user effort needed to accomplish the assigned tasks. Despite the fact that the BCI requires higher effort compared to the keyboard conditions, most subjects were able to complete the assigned tasks, and the proposed GR system is additionally shown able to handle the uncertainty in user input during SSVEP-based interaction. The SC application of the belief vector indicates that the benefits of the GR module are more pronounced for BCIs, compared to the keyboard interface. Significance. Being based on intuitive heuristics that model the behavior of the general population during the execution of navigation tasks, the proposed GR method can be used without prior tuning for the

  6. Development of Tremor Suppression Control System Using Adaptive Filter and Its Application to Meal-assist Robot

    Science.gov (United States)

    Yano, Ken'ichi; Ohara, Eiichi; Horihata, Satoshi; Aoki, Takaaki; Nishimoto, Yutaka

    A robot that supports independent living by assisting with eating and other activities which use the operator's own hand would be helpful for people suffering from tremors of the hand or any other body part. The proposed system using adaptive filter estimates tremor frequencies with a time-varying property and individual differences online. In this study, the estimated frequency is used to adjusting the tremor suppression filter which insulates the voluntary motion signal from the sensor signal containing tremor components. These system are integrated into the control system of the Meal-Assist Robot. As a result, the developed system makes it possible for the person with a tremor to manipulate the supporting robot without causing operability to deteriorate and without hazards due to improper operation.

  7. Adaptive neural control for dual-arm coordination of humanoid robot with unknown nonlinearities in output mechanism.

    Science.gov (United States)

    Liu, Zhi; Chen, Ci; Zhang, Yun; Chen, C L P

    2015-03-01

    To achieve an excellent dual-arm coordination of the humanoid robot, it is essential to deal with the nonlinearities existing in the system dynamics. The literatures so far on the humanoid robot control have a common assumption that the problem of output hysteresis could be ignored. However, in the practical applications, the output hysteresis is widely spread; and its existing limits the motion/force performances of the robotic system. In this paper, an adaptive neural control scheme, which takes the unknown output hysteresis and computational efficiency into account, is presented and investigated. In the controller design, the prior knowledge of system dynamics is assumed to be unknown. The motion error is guaranteed to converge to a small neighborhood of the origin by Lyapunov's stability theory. Simultaneously, the internal force is kept bounded and its error can be made arbitrarily small.

  8. Self-Adaptive Correction of Heading Direction in Stair Climbing for Tracked Mobile Robots Using Visual Servoing Approach

    Science.gov (United States)

    Ji, Peng; Song, Aiguo; Song, Zimo; Liu, Yuqing; Jiang, Guohua; Zhao, Guopu

    2017-02-01

    In this paper, we describe a heading direction correction algorithm for a tracked mobile robot. To save hardware resources as far as possible, the mobile robot’s wrist camera is used as the only sensor, which is rotated to face stairs. An ensemble heading deviation detector is proposed to help the mobile robot correct its heading direction. To improve the generalization ability, a multi-scale Gabor filter is used to process the input image previously. Final deviation result is acquired by applying the majority vote strategy on all the classifiers’ results. The experimental results show that our detector is able to enable the mobile robot to correct its heading direction adaptively while it is climbing the stairs.

  9. Fundamentals and advances in the development of remote welding fabrication systems

    Science.gov (United States)

    Agapakis, J. E.; Masubuchi, K.; Von Alt, C.

    1986-01-01

    Operational and man-machine issues for welding underwater, in outer space, and at other remote sites are investigated, and recent process developments are described. Probable remote welding missions are classified, and the essential characteristics of fundamental remote welding tasks are analyzed. Various possible operational modes for remote welding fabrication are identified, and appropriate roles for humans and machines are suggested. Human operator performance in remote welding fabrication tasks is discussed, and recent advances in the development of remote welding systems are described, including packaged welding systems, stud welding systems, remotely operated welding systems, and vision-aided remote robotic welding and autonomous welding systems.

  10. Real time computer controlled weld skate

    Science.gov (United States)

    Wall, W. A., Jr.

    1977-01-01

    A real time, adaptive control, automatic welding system was developed. This system utilizes the general case geometrical relationships between a weldment and a weld skate to precisely maintain constant weld speed and torch angle along a contoured workplace. The system is compatible with the gas tungsten arc weld process or can be adapted to other weld processes. Heli-arc cutting and machine tool routing operations are possible applications.

  11. Dynamic modelling and adaptive robust tracking control of a space robot with two-link flexible manipulators under unknown disturbances

    Science.gov (United States)

    Yang, Xinxin; Ge, Shuzhi Sam; He, Wei

    2018-04-01

    In this paper, both the closed-form dynamics and adaptive robust tracking control of a space robot with two-link flexible manipulators under unknown disturbances are developed. The dynamic model of the system is described with assumed modes approach and Lagrangian method. The flexible manipulators are represented as Euler-Bernoulli beams. Based on singular perturbation technique, the displacements/joint angles and flexible modes are modelled as slow and fast variables, respectively. A sliding mode control is designed for trajectories tracking of the slow subsystem under unknown but bounded disturbances, and an adaptive sliding mode control is derived for slow subsystem under unknown slowly time-varying disturbances. An optimal linear quadratic regulator method is proposed for the fast subsystem to damp out the vibrations of the flexible manipulators. Theoretical analysis validates the stability of the proposed composite controller. Numerical simulation results demonstrate the performance of the closed-loop flexible space robot system.

  12. Weld analysis and control system

    Science.gov (United States)

    Kennedy, Larry Z. (Inventor); Rodgers, Michael H. (Inventor); Powell, Bradley W. (Inventor); Burroughs, Ivan A. (Inventor); Goode, K. Wayne (Inventor)

    1994-01-01

    The invention is a Weld Analysis and Control System developed for active weld system control through real time weld data acquisition. Closed-loop control is based on analysis of weld system parameters and weld geometry. The system is adapted for use with automated welding apparatus having a weld controller which is capable of active electronic control of all aspects of a welding operation. Enhanced graphics and data displays are provided for post-weld analysis. The system provides parameter acquisition, including seam location which is acquired for active torch cross-seam positioning. Torch stand-off is also monitored for control. Weld bead and parent surface geometrical parameters are acquired as an indication of weld quality. These parameters include mismatch, peaking, undercut, underfill, crown height, weld width, puddle diameter, and other measurable information about the weld puddle regions, such as puddle symmetry, etc. These parameters provide a basis for active control as well as post-weld quality analysis and verification. Weld system parameters, such as voltage, current and wire feed rate, are also monitored and archived for correlation with quality parameters.

  13. Cognitive and sociocultural aspects of robotized technology: innovative processes of adaptation

    Science.gov (United States)

    Kvesko, S. B.; Kvesko, B. B.; Kornienko, M. A.; Nikitina, Y. A.; Pankova, N. M.

    2018-05-01

    The paper dwells upon interaction between socio-cultural phenomena and cognitive characteristics of robotized technology. The interdisciplinary approach was employed in order to cast light on the manifold and multilevel identity of scientific advance in terms of robotized technology within the mental realm. Analyzing robotized technology from the viewpoint of its significance for the modern society is one of the upcoming trends in the contemporary scientific realm. The robots under production are capable of interacting with people; this results in a growing necessity for the studies on social status of robotized technological items. Socio-cultural aspect of cognitive robotized technology is reflected in the fact that the nature becomes ‘aware’ of itself via human brain, a human being tends to strives for perfection in their intellectual and moral dimensions.

  14. Reduced short term adaptation to robot generated dynamic environment in children affected by Cerebral Palsy.

    Science.gov (United States)

    Masia, Lorenzo; Frascarelli, Flaminia; Morasso, Pietro; Di Rosa, Giuseppe; Petrarca, Maurizio; Castelli, Enrico; Cappa, Paolo

    2011-05-21

    It is known that healthy adults can quickly adapt to a novel dynamic environment, generated by a robotic manipulandum as a structured disturbing force field. We suggest that it may be of clinical interest to evaluate to which extent this kind of motor learning capability is impaired in children affected by cerebal palsy. We adapted the protocol already used with adults, which employs a velocity dependant viscous field, and compared the performance of a group of subjects affected by Cerebral Palsy (CP group, 7 subjects) with a Control group of unimpaired age-matched children. The protocol included a familiarization phase (FA), during which no force was applied, a force field adaptation phase (CF), and a wash-out phase (WO) in which the field was removed. During the CF phase the field was shut down in a number of randomly selected "catch" trials, which were used in order to evaluate the "learning index" for each single subject and the two groups. Lateral deviation, speed and acceleration peaks and average speed were evaluated for each trajectory; a directional analysis was performed in order to inspect the role of the limb's inertial anisotropy in the different experimental phases. During the FA phase the movements of the CP subjects were more curved, displaying greater and variable directional error; over the course of the CF phase both groups showed a decreasing trend in the lateral error and an after-effect at the beginning of the wash-out, but the CP group had a non significant adaptation rate and a lower learning index, suggesting that CP subjects have reduced ability to learn to compensate external force. Moreover, a directional analysis of trajectories confirms that the control group is able to better predict the force field by tuning the kinematic features of the movements along different directions in order to account for the inertial anisotropy of arm. Spatial abnormalities in children affected by cerebral palsy may be related not only to disturbance in

  15. Reduced short term adaptation to robot generated dynamic environment in children affected by Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Di Rosa Giuseppe

    2011-05-01

    Full Text Available Abstract Background It is known that healthy adults can quickly adapt to a novel dynamic environment, generated by a robotic manipulandum as a structured disturbing force field. We suggest that it may be of clinical interest to evaluate to which extent this kind of motor learning capability is impaired in children affected by cerebal palsy. Methods We adapted the protocol already used with adults, which employs a velocity dependant viscous field, and compared the performance of a group of subjects affected by Cerebral Palsy (CP group, 7 subjects with a Control group of unimpaired age-matched children. The protocol included a familiarization phase (FA, during which no force was applied, a force field adaptation phase (CF, and a wash-out phase (WO in which the field was removed. During the CF phase the field was shut down in a number of randomly selected "catch" trials, which were used in order to evaluate the "learning index" for each single subject and the two groups. Lateral deviation, speed and acceleration peaks and average speed were evaluated for each trajectory; a directional analysis was performed in order to inspect the role of the limb's inertial anisotropy in the different experimental phases. Results During the FA phase the movements of the CP subjects were more curved, displaying greater and variable directional error; over the course of the CF phase both groups showed a decreasing trend in the lateral error and an after-effect at the beginning of the wash-out, but the CP group had a non significant adaptation rate and a lower learning index, suggesting that CP subjects have reduced ability to learn to compensate external force. Moreover, a directional analysis of trajectories confirms that the control group is able to better predict the force field by tuning the kinematic features of the movements along different directions in order to account for the inertial anisotropy of arm. Conclusions Spatial abnormalities in children affected

  16. Adaptive pseudo-color enhancement method of weld radiographic images based on HSI color space and self-transformation of pixels

    Science.gov (United States)

    Jiang, Hongquan; Zhao, Yalin; Gao, Jianmin; Gao, Zhiyong

    2017-06-01

    The radiographic testing (RT) image of a steam turbine manufacturing enterprise has the characteristics of low gray level, low contrast, and blurriness, which lead to a substandard image quality. Moreover, it is not conducive for human eyes to detect and evaluate defects. This study proposes an adaptive pseudo-color enhancement method for weld radiographic images based on the hue, saturation, and intensity (HSI) color space and the self-transformation of pixels to solve these problems. First, the pixel's self-transformation is performed to the pixel value of the original RT image. The function value after the pixel's self-transformation is assigned to the HSI components in the HSI color space. Thereafter, the average intensity of the enhanced image is adaptively adjusted to 0.5 according to the intensity of the original image. Moreover, the hue range and interval can be adjusted according to personal habits. Finally, the HSI components after the adaptive adjustment can be transformed to display in the red, green, and blue color space. Numerous weld radiographic images from a steam turbine manufacturing enterprise are used to validate the proposed method. The experimental results show that the proposed pseudo-color enhancement method can improve image definition and make the target and background areas distinct in weld radiographic images. The enhanced images will be more conducive for defect recognition. Moreover, the image enhanced using the proposed method conforms to the human eye visual properties, and the effectiveness of defect recognition and evaluation can be ensured.

  17. Adaptive pseudo-color enhancement method of weld radiographic images based on HSI color space and self-transformation of pixels.

    Science.gov (United States)

    Jiang, Hongquan; Zhao, Yalin; Gao, Jianmin; Gao, Zhiyong

    2017-06-01

    The radiographic testing (RT) image of a steam turbine manufacturing enterprise has the characteristics of low gray level, low contrast, and blurriness, which lead to a substandard image quality. Moreover, it is not conducive for human eyes to detect and evaluate defects. This study proposes an adaptive pseudo-color enhancement method for weld radiographic images based on the hue, saturation, and intensity (HSI) color space and the self-transformation of pixels to solve these problems. First, the pixel's self-transformation is performed to the pixel value of the original RT image. The function value after the pixel's self-transformation is assigned to the HSI components in the HSI color space. Thereafter, the average intensity of the enhanced image is adaptively adjusted to 0.5 according to the intensity of the original image. Moreover, the hue range and interval can be adjusted according to personal habits. Finally, the HSI components after the adaptive adjustment can be transformed to display in the red, green, and blue color space. Numerous weld radiographic images from a steam turbine manufacturing enterprise are used to validate the proposed method. The experimental results show that the proposed pseudo-color enhancement method can improve image definition and make the target and background areas distinct in weld radiographic images. The enhanced images will be more conducive for defect recognition. Moreover, the image enhanced using the proposed method conforms to the human eye visual properties, and the effectiveness of defect recognition and evaluation can be ensured.

  18. Challenges to Resistance Welding

    DEFF Research Database (Denmark)

    Song, Quanfeng

    This report originates from the compulsory defense during my Ph.D. study at the Technical University of Denmark. Resistance welding is an old and well-proven technology. Yet the emergence of more and more new materials, new designs, invention off new joining techniques, and more stringent...... requirement in quality have imposed challenges to the resistance welding. More some research and development have to be done to adapt the old technology to the manufacturing industry of the 21st century. In the 1st part of the report, the challenging factors to the resistance welding are reviewed. Numerical...... simulation of resistance welding has been under development for many years. Yet it is no easy to make simulation results reliable and accurate because of the complexity of resistance welding process. In the 2nd part of the report numerical modeling of resistance welding is reviewed, some critical factors...

  19. Robotic arm

    International Nuclear Information System (INIS)

    Kwech, H.

    1989-01-01

    A robotic arm positionable within a nuclear vessel by access through a small diameter opening and having a mounting tube supported within the vessel and mounting a plurality of arm sections for movement lengthwise of the mounting tube as well as for movement out of a window provided in the wall of the mounting tube is disclosed. An end effector, such as a grinding head or welding element, at an operating end of the robotic arm, can be located and operated within the nuclear vessel through movement derived from six different axes of motion provided by mounting and drive connections between arm sections of the robotic arm. The movements are achieved by operation of remotely-controllable servo motors, all of which are mounted at a control end of the robotic arm to be outside the nuclear vessel. 23 figs

  20. Robotic arm

    Science.gov (United States)

    Kwech, Horst

    1989-04-18

    A robotic arm positionable within a nuclear vessel by access through a small diameter opening and having a mounting tube supported within the vessel and mounting a plurality of arm sections for movement lengthwise of the mounting tube as well as for movement out of a window provided in the wall of the mounting tube. An end effector, such as a grinding head or welding element, at an operating end of the robotic arm, can be located and operated within the nuclear vessel through movement derived from six different axes of motion provided by mounting and drive connections between arm sections of the robotic arm. The movements are achieved by operation of remotely-controllable servo motors, all of which are mounted at a control end of the robotic arm to be outside the nuclear vessel.

  1. Short-term locomotor adaptation to a robotic ankle exoskeleton does not alter soleus Hoffmann reflex amplitude.

    Science.gov (United States)

    Kao, Pei-Chun; Lewis, Cara L; Ferris, Daniel P

    2010-07-26

    To improve design of robotic lower limb exoskeletons for gait rehabilitation, it is critical to identify neural mechanisms that govern locomotor adaptation to robotic assistance. Previously, we demonstrated soleus muscle recruitment decreased by approximately 35% when walking with a pneumatically-powered ankle exoskeleton providing plantar flexor torque under soleus proportional myoelectric control. Since a substantial portion of soleus activation during walking results from the stretch reflex, increased reflex inhibition is one potential mechanism for reducing soleus recruitment when walking with exoskeleton assistance. This is clinically relevant because many neurologically impaired populations have hyperactive stretch reflexes and training to reduce the reflexes could lead to substantial improvements in their motor ability. The purpose of this study was to quantify soleus Hoffmann (H-) reflex responses during powered versus unpowered walking. We tested soleus H-reflex responses in neurologically intact subjects (n=8) that had trained walking with the soleus controlled robotic ankle exoskeleton. Soleus H-reflex was tested at the mid and late stance while subjects walked with the exoskeleton on the treadmill at 1.25 m/s, first without power (first unpowered), then with power (powered), and finally without power again (second unpowered). We also collected joint kinematics and electromyography. When the robotic plantar flexor torque was provided, subjects walked with lower soleus electromyographic (EMG) activation (27-48%) and had concomitant reductions in H-reflex amplitude (12-24%) compared to the first unpowered condition. The H-reflex amplitude in proportion to the background soleus EMG during powered walking was not significantly different from the two unpowered conditions. These findings suggest that the nervous system does not inhibit the soleus H-reflex in response to short-term adaption to exoskeleton assistance. Future studies should determine if the

  2. Intuitive adaptive orientation control of assistive robots for people living with upper limb disabilities.

    Science.gov (United States)

    Vu, Dinh-Son; Allard, Ulysse Cote; Gosselin, Clement; Routhier, Francois; Gosselin, Benoit; Campeau-Lecours, Alexandre

    2017-07-01

    Robotic assistive devices enhance the autonomy of individuals living with physical disabilities in their day-to-day life. Although the first priority for such devices is safety, they must also be intuitive and efficient from an engineering point of view in order to be adopted by a broad range of users. This is especially true for assistive robotic arms, as they are used for the complex control tasks of daily living. One challenge in the control of such assistive robots is the management of the end-effector orientation which is not always intuitive for the human operator, especially for neophytes. This paper presents a novel orientation control algorithm designed for robotic arms in the context of human-robot interaction. This work aims at making the control of the robot's orientation easier and more intuitive for the user, in particular, individuals living with upper limb disabilities. The performance and intuitiveness of the proposed orientation control algorithm is assessed through two experiments with 25 able-bodied subjects and shown to significantly improve on both aspects.

  3. Multiple Decoupled CPGs with Local Sensory Feedback for Adaptive Locomotion Behaviors of Bio-inspired Walking Robots

    DEFF Research Database (Denmark)

    Shaker Barikhan, Subhi; Wörgötter, Florentin; Manoonpong, Poramate

    2014-01-01

    , and their interactions during body and leg movements through the environment. Based on this concept, we present here an artificial bio-inspired walking system. Its intralimb coordination is formed by multiple decoupled CPGs while its interlimb coordination is attained by the interactions between body dynamics...... and the environment through local sensory feedback of each leg. Simulation results show that this bio-inspired approach generates self-organizing emergent locomotion allowing the robot to adaptively form regular patterns, to stably walk while pushing an object with its front legs or performing multiple stepping...

  4. Simulation of Welding Distortions in Theory and Practice

    DEFF Research Database (Denmark)

    Birk-Sørensen, Martin; Kierkegaard, Henning

    1997-01-01

    by an optimised welding order. Welding test samples prove that the constraint of the sample and the time between each pass in a multipass weld affect the magnitude of distortion. Experiments with welding specimens in the form of butt-and fillet welds have been carried out. They show angular deflections as well......In the last few years the use of robot welding processes has increased significatnly. The programming of the robots has until now mainly focused on high efficiency, i.e.high torch rate time, and hence, minimising the inefficient "travelling" time. Together with developing high-performance welding...... due to cutting and welding and parlty in the form of dimensional variation due to human factors. Measurements have been made of the production line for assemblies. The measurements show that distortions related to the multirobot welding are a factor which can rather easily be controlled...

  5. Welding hazards

    International Nuclear Information System (INIS)

    Khan, M.A.

    1992-01-01

    Welding technology is advancing rapidly in the developed countries and has converted into a science. Welding involving the use of electricity include resistance welding. Welding shops are opened in residential area, which was causing safety hazards, particularly the teenagers and children who eagerly see the welding arc with their naked eyes. There are radiation hazards from ultra violet rays which irritate the skin, eye irritation. Welding arc light of such intensity could damage the eyes. (Orig./A.B.)

  6. Reusable Electronics and Adaptable Communication as Implemented in the Odin Modular Robot

    DEFF Research Database (Denmark)

    Garcia, Ricardo Franco Mendoza; Lyder, Andreas; Christensen, David Johan

    2009-01-01

    This paper describes the electronics and communication system of Odin, a novel heterogeneous modular robot made of links and joints. The electronics is divided into two printed circuit boards: a General board with reusable components and a Specific board with non-reusable components. While...... electrical signals. The implementations of actuator and power links show that splitting the electronics into General and Specific boards allows rapid development of different types of modules, and an analysis of performance indicates that the communication system is simple, fast and flexible....... As the electronic design reuses approx. 50% of components between two different types of modules, we find it convenient for heterogeneous modular robots where production costs demand a small set of parts. In addition, as the features of the communication system are desirable in modular robots, we think...

  7. Adaptive Strategy for Online Gait Learning Evaluated on the Polymorphic Robotic LocoKit

    DEFF Research Database (Denmark)

    Christensen, David Johan; Larsen, Jørgen Christian; Stoy, Kasper

    2012-01-01

    This paper presents experiments with a morphologyindependent, life-long strategy for online learning of locomotion gaits, performed on a quadruped robot constructed from the LocoKit modular robot. The learning strategy applies a stochastic optimization algorithm to optimize eight open parameters...... of a central pattern generator based gait implementation. We observe that the strategy converges in roughly ten minutes to gaits of similar or higher velocity than a manually designed gait and that the strategy readapts in the event of failed actuators. In future work we plan to study co-learning...

  8. Learning-based adaptive prescribed performance control of postcapture space robot-target combination without inertia identifications

    Science.gov (United States)

    Wei, Caisheng; Luo, Jianjun; Dai, Honghua; Bian, Zilin; Yuan, Jianping

    2018-05-01

    In this paper, a novel learning-based adaptive attitude takeover control method is investigated for the postcapture space robot-target combination with guaranteed prescribed performance in the presence of unknown inertial properties and external disturbance. First, a new static prescribed performance controller is developed to guarantee that all the involved attitude tracking errors are uniformly ultimately bounded by quantitatively characterizing the transient and steady-state performance of the combination. Then, a learning-based supplementary adaptive strategy based on adaptive dynamic programming is introduced to improve the tracking performance of static controller in terms of robustness and adaptiveness only utilizing the input/output data of the combination. Compared with the existing works, the prominent advantage is that the unknown inertial properties are not required to identify in the development of learning-based adaptive control law, which dramatically decreases the complexity and difficulty of the relevant controller design. Moreover, the transient and steady-state performance is guaranteed a priori by designer-specialized performance functions without resorting to repeated regulations of the controller parameters. Finally, the three groups of illustrative examples are employed to verify the effectiveness of the proposed control method.

  9. Adaptive Hierarchical Control for the Muscle Strength Training of Stroke Survivors in Robot-Aided Upper-Limb Rehabilitation

    Directory of Open Access Journals (Sweden)

    Guozheng Xu

    2012-10-01

    Full Text Available Muscle strength training for stroke patients is of vital importance for helping survivors to progressively restore muscle strength and improve the performance of their activities in daily living (ADL. An adaptive hierarchical therapy control framework which integrates the patient's real biomechanical state estimation with task-performance quantitative evaluation is proposed. Firstly, a high-level progressive resistive supervisory controller is designed to determine the resistive force base for each training session based on the patient's online task-performance evaluation. Then, a low-level adaptive resistive force triggered controller is presented to further regulate the interactive resistive force corresponding to the patient's real-time biomechanical state – characterized by the patient's bio-damping and bio-stiffness in the course of one training session, so that the patient is challenged in a moderate but engaging and motivating way. Finally, a therapeutic robot system using a Barrett WAM™ compliant manipulator is set up. We recruited eighteen inpatient and outpatient stroke participants who were randomly allocated in experimental (robot-aided and control (conventional physical therapy groups and enrolled for sixteen weeks of progressive resistance training. The preliminary results show that the proposed therapy control strategies can enhance the recovery of strength and motor control ability.

  10. An adaptive PID like controller using mix locally recurrent neural network for robotic manipulator with variable payload.

    Science.gov (United States)

    Sharma, Richa; Kumar, Vikas; Gaur, Prerna; Mittal, A P

    2016-05-01

    Being complex, non-linear and coupled system, the robotic manipulator cannot be effectively controlled using classical proportional-integral-derivative (PID) controller. To enhance the effectiveness of the conventional PID controller for the nonlinear and uncertain systems, gains of the PID controller should be conservatively tuned and should adapt to the process parameter variations. In this work, a mix locally recurrent neural network (MLRNN) architecture is investigated to mimic a conventional PID controller which consists of at most three hidden nodes which act as proportional, integral and derivative node. The gains of the mix locally recurrent neural network based PID (MLRNNPID) controller scheme are initialized with a newly developed cuckoo search algorithm (CSA) based optimization method rather than assuming randomly. A sequential learning based least square algorithm is then investigated for the on-line adaptation of the gains of MLRNNPID controller. The performance of the proposed controller scheme is tested against the plant parameters uncertainties and external disturbances for both links of the two link robotic manipulator with variable payload (TL-RMWVP). The stability of the proposed controller is analyzed using Lyapunov stability criteria. A performance comparison is carried out among MLRNNPID controller, CSA optimized NNPID (OPTNNPID) controller and CSA optimized conventional PID (OPTPID) controller in order to establish the effectiveness of the MLRNNPID controller. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  11. Information-Fusion Methods Based Simultaneous Localization and Mapping for Robot Adapting to Search and Rescue Postdisaster Environments

    Directory of Open Access Journals (Sweden)

    Hongling Wang

    2018-01-01

    Full Text Available The first application of utilizing unique information-fusion SLAM (IF-SLAM methods is developed for mobile robots performing simultaneous localization and mapping (SLAM adapting to search and rescue (SAR environments in this paper. Several fusion approaches, parallel measurements filtering, exploration trajectories fusing, and combination sensors’ measurements and mobile robots’ trajectories, are proposed. The novel integration particle filter (IPF and optimal improved EKF (IEKF algorithms are derived for information-fusion systems to perform SLAM task in SAR scenarios. The information-fusion architecture consists of multirobots and multisensors (MAM; multiple robots mount on-board laser range finder (LRF sensors, localization sonars, gyro odometry, Kinect-sensor, RGB-D camera, and other proprioceptive sensors. This information-fusion SLAM (IF-SLAM is compared with conventional methods, which indicates that fusion trajectory is more consistent with estimated trajectories and real observation trajectories. The simulations and experiments of SLAM process are conducted in both cluttered indoor environment and outdoor collapsed unstructured scenario, and experimental results validate the effectiveness of the proposed information-fusion methods in improving SLAM performances adapting to SAR scenarios.

  12. Individualised and adaptive upper limb rehabilitation with industrial robot using dynamic movement primitives

    DEFF Research Database (Denmark)

    Nielsen, Jacob; Sørensen, Anders Stengaard; Christensen, Thomas Søndergaard

    Stroke is a leading cause of serious long-term disability. Post-stroke rehabilitation is a demanding task for the patient and a costly challenge for both society and healthcare systems. We present a novel approach for training of upper extremities after a stroke by utilising an industrial robotic...

  13. Multi-optimization Criteria-based Robot Behavioral Adaptability and Motion Planning

    International Nuclear Information System (INIS)

    Pin, Francois G.

    2003-01-01

    Our overall objective is the development of a generalized methodology and code for the automated generation of the kinematics equations of robots and for the analytical solution of their motion planning equations subject to time-varying constraints, behavioral objectives and modular configuration

  14. Multi-optimization Criteria-based Robot Behavioral Adaptability and Motion Planning

    International Nuclear Information System (INIS)

    Pin, Grancois G.

    2004-01-01

    Our overall objective is the development of a generalized methodology and code for the automated generation of the kinematics equations of robots and for the analytical solution of their motion planning equations subject to time-varying constraints, behavioral objectives, and modular configuration

  15. A distributed and morphology-independent strategy for adaptive locomotion in self-reconfigurable modular robots

    DEFF Research Database (Denmark)

    Christensen, David Johan; Schultz, Ulrik Pagh; Stoy, Kasper

    2013-01-01

    In this paper, we present a distributed reinforcement learning strategy for morphology-independent lifelong gait learning for modular robots. All modules run identical controllers that locally and independently optimize their action selection based on the robot’s velocity as a global, shared reward...

  16. Welding Curriculum.

    Science.gov (United States)

    Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

    This competency-based curriculum guide is a handbook for the development of welding trade programs. Based on a survey of Alaskan welding employers, it includes all competencies a student should acquire in such a welding program. The handbook stresses the importance of understanding the principles associated with the various elements of welding.…

  17. Distributed cerebellar plasticity implements adaptable gain control in a manipulation task: a closed-loop robotic simulation

    Directory of Open Access Journals (Sweden)

    Jesus A Garrido Alcazar

    2013-10-01

    Full Text Available Adaptable gain regulation is at the core of the forward controller operation performed by the cerebro-cerebellar loops and it allows the intensity of motor acts to be finely tuned in a predictive manner. In order to learn and store information about body-object dynamics and to generate an internal model of movement, the cerebellum is thought to employ long-term synaptic plasticity. LTD at the PF-PC synapse has classically been assumed to subserve this function (Marr, 1969. However, this plasticity alone cannot account for the broad dynamic ranges and time scales of cerebellar adaptation. We therefore tested the role of plasticity distributed over multiple synaptic sites (Gao et al., 2012; Hansel et al., 2001 by generating an analog cerebellar model embedded into a control loop connected to a robotic simulator. The robot used a three-joint arm and performed repetitive fast manipulations with different masses along an 8-shape trajectory. In accordance with biological evidence, the cerebellum model was endowed with both LTD and LTP at the PF-PC, MF-DCN and PC-DCN synapses. This resulted in a network scheme whose effectiveness was extended considerably compared to one including just PF-PC synaptic plasticity. Indeed, the system including distributed plasticity reliably self-adapted to manipulate different masses and to learn the arm-object dynamics over a time course that included fast learning and consolidation, along the lines of what has been observed in behavioral tests. In particular, PF-PC plasticity operated as a time correlator between the actual input state and the system error, while MF-DCN and PC-DCN plasticity played a key role in generating the gain controller. This model suggests that distributed synaptic plasticity allows generation of the complex learning properties of the cerebellum. The incorporation of further plasticity mechanisms and of spiking signal processing will allow this concept to be extended in a more realistic

  18. Comparison of ALE finite element method and adaptive smoothed finite element method for the numerical simulation of friction stir welding

    NARCIS (Netherlands)

    van der Stelt, A.A.; Bor, Teunis Cornelis; Geijselaers, Hubertus J.M.; Quak, W.; Akkerman, Remko; Huetink, Han; Menary, G

    2011-01-01

    In this paper, the material flow around the pin during friction stir welding (FSW) is simulated using a 2D plane strain model. A pin rotates without translation in a disc with elasto-viscoplastic material properties and the outer boundary of the disc is clamped. Two numerical methods are used to

  19. Distributed Recurrent Neural Forward Models with Synaptic Adaptation and CPG-based control for Complex Behaviors of Walking Robots

    Directory of Open Access Journals (Sweden)

    Sakyasingha eDasgupta

    2015-09-01

    Full Text Available Walking animals, like stick insects, cockroaches or ants, demonstrate a fascinating range of locomotive abilities and complex behaviors. The locomotive behaviors can consist of a variety of walking patterns along with adaptation that allow the animals to deal with changes in environmental conditions, like uneven terrains, gaps, obstacles etc. Biological study has revealed that such complex behaviors are a result of a combination of biomechanics and neural mechanism thus representing the true nature of embodied interactions. While the biomechanics helps maintain flexibility and sustain a variety of movements, the neural mechanisms generate movements while making appropriate predictions crucial for achieving adaptation. Such predictions or planning ahead can be achieved by way of internal models that are grounded in the overall behavior of the animal. Inspired by these findings, we present here, an artificial bio-inspired walking system which effectively combines biomechanics (in terms of the body and leg structures with the underlying neural mechanisms. The neural mechanisms consist of 1 central pattern generator based control for generating basic rhythmic patterns and coordinated movements, 2 distributed (at each leg recurrent neural network based adaptive forward models with efference copies as internal models for sensory predictions and instantaneous state estimations, and 3 searching and elevation control for adapting the movement of an individual leg to deal with different environmental conditions. Using simulations we show that this bio-inspired approach with adaptive internal models allows the walking robot to perform complex locomotive behaviors as observed in insects, including walking on undulated terrains, crossing large gaps as well as climbing over high obstacles. Furthermore we demonstrate that the newly developed recurrent network based approach to sensorimotor prediction outperforms the previous state of the art adaptive neuron

  20. Testing biological hypotheses with embodied robots: adaptations, accidents, and by-products in the evolution of vertebrates

    Directory of Open Access Journals (Sweden)

    Sonia F Roberts

    2014-11-01

    Full Text Available Evolutionary robotics allows biologists to test hypotheses about extinct animals. We modeled some of the first vertebrates, jawless fishes, in order to study the evolution of the trait after which vertebrates are named: vertebrae. We tested the hypothesis that vertebrae are an adaptation for enhanced feeding and fleeing performance. We created a population of autonomous embodied robots, Preyro, in which the number of vertebrae, N, were free to evolve. In addition, two other traits, the span of the caudal fin, b, and the predator detection threshold, ζ, a proxy for the lateral line sensory system, were also allowed to evolve. These three traits were chosen because they evolved early in vertebrates, are all potentially important in feeding and fleeing, and vary in form among species. Preyro took on individual identities in a given generation as defined by the population’s six diploid genotypes, Gi. Each Gi was a 3-tuple, with each element an integer specifying N, b, and, ζ. The small size of the population allowed for genetic drift to operate in concert with random mutation and mating; the presence of these mechanisms of chance provided an opportunity for N to evolve by accident. The presence of three evolvable traits provided an opportunity for direct selection on b and/or ζ to evolve N as a by-product linked trait correlation. In selection trials, different Gi embodied in Preyro attempted to feed at a light source and then flee to avoid a predator robot in pursuit. The fitness of each Gi was calculated from five different types of performance: speed, acceleration, distance to the light, distance to the predator, and the number of predator escapes initiated. In each generation, we measured the selection differential, the selection gradient, the strength of chance, and the indirect correlation selection gradient. These metrics allowed us to understand the relative contributions of the three mechanisms: direct selection, chance, and indirect

  1. An adaptive scheme for robot localization and mapping with dynamically configurable inter-beacon range measurements.

    Science.gov (United States)

    Torres-González, Arturo; Martinez-de Dios, Jose Ramiro; Ollero, Anibal

    2014-04-25

    This work is motivated by robot-sensor network cooperation techniques where sensor nodes (beacons) are used as landmarks for range-only (RO) simultaneous localization and mapping (SLAM). This paper presents a RO-SLAM scheme that actuates over the measurement gathering process using mechanisms that dynamically modify the rate and variety of measurements that are integrated in the SLAM filter. It includes a measurement gathering module that can be configured to collect direct robot-beacon and inter-beacon measurements with different inter-beacon depth levels and at different rates. It also includes a supervision module that monitors the SLAM performance and dynamically selects the measurement gathering configuration balancing SLAM accuracy and resource consumption. The proposed scheme has been applied to an extended Kalman filter SLAM with auxiliary particle filters for beacon initialization (PF-EKF SLAM) and validated with experiments performed in the CONET Integrated Testbed. It achieved lower map and robot errors (34% and 14%, respectively) than traditional methods with a lower computational burden (16%) and similar beacon energy consumption.

  2. Automatic monitoring of the alignment and wear of vibration welding equipment

    Science.gov (United States)

    Spicer, John Patrick; Cai, Wayne W.; Chakraborty, Debejyo; Mink, Keith

    2017-05-23

    A vibration welding system includes vibration welding equipment having a welding horn and anvil, a host machine, a check station, and a welding robot. At least one displacement sensor is positioned with respect to one of the welding equipment and the check station. The robot moves the horn and anvil via an arm to the check station, when a threshold condition is met, i.e., a predetermined amount of time has elapsed or a predetermined number of welds have been completed. The robot moves the horn and anvil to the check station, activates the at least one displacement sensor, at the check station, and determines a status condition of the welding equipment by processing the received signals. The status condition may be one of the alignment of the vibration welding equipment and the wear or degradation of the vibration welding equipment.

  3. An indirect adaptive neural control of a visual-based quadrotor robot for pursuing a moving target.

    Science.gov (United States)

    Shirzadeh, Masoud; Amirkhani, Abdollah; Jalali, Aliakbar; Mosavi, Mohammad R

    2015-11-01

    This paper aims to use a visual-based control mechanism to control a quadrotor type aerial robot which is in pursuit of a moving target. The nonlinear nature of a quadrotor, on the one hand, and the difficulty of obtaining an exact model for it, on the other hand, constitute two serious challenges in designing a controller for this UAV. A potential solution for such problems is the use of intelligent control methods such as those that rely on artificial neural networks and other similar approaches. In addition to the two mentioned problems, another problem that emerges due to the moving nature of a target is the uncertainty that exists in the target image. By employing an artificial neural network with a Radial Basis Function (RBF) an indirect adaptive neural controller has been designed for a quadrotor robot in search of a moving target. The results of the simulation for different paths show that the quadrotor has efficiently tracked the moving target. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  4. A zero phase adaptive fuzzy Kalman filter for physiological tremor suppression in robotically assisted minimally invasive surgery.

    Science.gov (United States)

    Sang, Hongqiang; Yang, Chenghao; Liu, Fen; Yun, Jintian; Jin, Guoguang; Chen, Fa

    2016-12-01

    Hand physiological tremor of surgeons can cause vibration at the surgical instrument tip, which may make it difficult for the surgeon to perform fine manipulations of tissue, needles, and sutures. A zero phase adaptive fuzzy Kalman filter (ZPAFKF) is proposed to suppress hand tremor and vibration of a robotic surgical system. The involuntary motion can be reduced by adding a compensating signal that has the same magnitude and frequency but opposite phase with the tremor signal. Simulations and experiments using different filters were performed. Results show that the proposed filter can avoid the loss of useful motion information and time delay, and better suppress minor and varying tremor. The ZPAFKF can provide less error, preferred accuracy, better tremor estimation, and more desirable compensation performance, to suppress hand tremor and decrease vibration at the surgical instrument tip. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Advanced Welding Concepts

    Science.gov (United States)

    Ding, Robert J.

    2010-01-01

    Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.

  6. Resistance seam welding

    International Nuclear Information System (INIS)

    Schueler, A.W.

    1977-01-01

    The advantages and disadvantages of the resistance seam welding process are presented. Types of seam welds, types of seam welding machines, seam welding power supplies, resistance seam welding parameters and seam welding characteristics of various metals

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

    Science.gov (United States)

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

    2017-08-01

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

  8. A Basic Architecture of an Autonomous Adaptive System With Conscious-Like Function for a Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Yasuo Kinouchi

    2018-04-01

    Full Text Available In developing a humanoid robot, there are two major objectives. One is developing a physical robot having body, hands, and feet resembling those of human beings and being able to similarly control them. The other is to develop a control system that works similarly to our brain, to feel, think, act, and learn like ours. In this article, an architecture of a control system with a brain-oriented logical structure for the second objective is proposed. The proposed system autonomously adapts to the environment and implements a clearly defined “consciousness” function, through which both habitual behavior and goal-directed behavior are realized. Consciousness is regarded as a function for effective adaptation at the system-level, based on matching and organizing the individual results of the underlying parallel-processing units. This consciousness is assumed to correspond to how our mind is “aware” when making our moment to moment decisions in our daily life. The binding problem and the basic causes of delay in Libet’s experiment are also explained by capturing awareness in this manner. The goal is set as an image in the system, and efficient actions toward achieving this goal are selected in the goal-directed behavior process. The system is designed as an artificial neural network and aims at achieving consistent and efficient system behavior, through the interaction of highly independent neural nodes. The proposed architecture is based on a two-level design. The first level, which we call the “basic-system,” is an artificial neural network system that realizes consciousness, habitual behavior and explains the binding problem. The second level, which we call the “extended-system,” is an artificial neural network system that realizes goal-directed behavior.

  9. An example of the use of robotics in French nuclear power plants the ISIS robot

    International Nuclear Information System (INIS)

    Seguy, J.; Thirion, H.

    1988-01-01

    The authors report how Robotics in French nuclear power plants (NPP) is used to solve maintenance problems. One of the most typical example of the use of robotics in French NPP is the ISIS robot. The first generation of this robot has performed the repair of corroded upper internal structures in Chinon A3 gaz cooled reactor. Two robots of this type have successfully welded more than 200 repair parts in the core without major failure during more than 12,000 hours

  10. Welding process automation in power machine building

    International Nuclear Information System (INIS)

    Mel'bard, S.N.; Shakhnov, A.F.; Shergov, I.V.

    1977-01-01

    The level of welding automation operations in power engineering and ways of its enhancement are highlighted. Used as the examples of comlex automation are an apparatus for the horizontal welding of turbine rotors, remotely controlled automatic machine for welding ring joint of large-sized vessels, equipment for the electron-beam welding of steam turbine assemblies of alloyed steels. The prospects of industrial robots are noted. The importance of the complex automation of technological process, including stocking, assemblying, transportation and auxiliary operations, is emphasized

  11. A Feed-forward Geometrical Compensation and Adaptive Feedback Control Algorithm for Hydraulic Robot Manipulators

    DEFF Research Database (Denmark)

    Conrad, Finn; Zhou, Jianjun; Gabacik, Andrzej

    1998-01-01

    Invited paper presents a new control algorithm based on feed-forward geometrical compensation strategy combined with adaptive feedback control.......Invited paper presents a new control algorithm based on feed-forward geometrical compensation strategy combined with adaptive feedback control....

  12. A robot-automated work site for repair of the Chinon A3 reactor

    International Nuclear Information System (INIS)

    Raynal, A.

    1987-01-01

    In 1982, following degradation due to corrosion of low-carbon steel by carbon dioxide gas, the utility undertook to repair some of the support structures at Chinon A3. This involved consolidation and reinforcing thermocouples and gas monitor pipeworks supports. A welding process was selected and the use of robots became indispensable because of the large number of components to be replaced (200 per outage). Two robots, supplied with tool heads and replacement components from outside the reactor were used. The robots and their servers were coordinated by a central computer and monitored by a closed circuit television system. Each repair operation was performed after ''training'' on a full-scale mockup of the top of the reactor reconstructed from telemetry of the real reactor dimensions. Since becoming operational in June 1986, the robots have accumulated over 20 000 hours of operation and seventy parts have been welded to the reactor. A 3D CAD system has been adapted to simulate the robots and analyse long trajectories in order to reduce robot learning time [fr

  13. Adaptive Control for Revolute Joints Robot Manipulator with Uncertain/Unknown Dynamic Parameters and in Presence of Disturbance in Control Input

    DEFF Research Database (Denmark)

    Seyed Sakha, Masoud; Shaker, Hamid Reza

    2017-01-01

    This paper presents an effective adaptive controller for revolute joints robot manipulator where the control input is accompanied with a random disturbance (with unknown PSD). It is clear that, disturbance can compromise the overall performance of the system. To cope with this problem, a control...... technique is proposed which uses the concept of exponential practical stability. Unlike other counterparts, the proposed method does not need information such as the physical parameters of robot and gravitational acceleration. The results show that the proposed controller achieves an excellent performance...

  14. ITER lip seal welding and cutting developments

    International Nuclear Information System (INIS)

    Levesy, B.; Cordier, J.J.; Jokinen, T.; Kujanpää, V.; Karhu, M.; Le Barbier, R.; Määttä, T.; Martins, J.P.; Utin, Y.

    2015-01-01

    Highlights: • Different TIG and Laser welding techniques are tested. • Twin spot laser welding techniques is the best. • Limited heat input gives a stable weld pool in all positions. • Penetrations is achieved. • Lip seal welding and cutting with a robotic arm is successfully performed on a representative mock-up. - Abstract: The welded lip seals form part of the torus primary vacuum boundary in between the port plugs and the vacuum vessel, and are classified as Protection Important Component. In order to refurbish the port plugs or the in-vessel components, port plugs have to be removed from the machine. The lip seal design must enable up to ten opening of the vacuum vessel during the life time operation of the ITER machine. Therefore proven, remote reliable cutting and re-welding are essential, as these operations need to be performed in the port cells in a nuclear environment, where human presence will be restricted. Moreover, the combination of size of the components to be welded (∼10 m long vacuum compatible thin welds) and the congested environment close to the core of the machine constraint the type and size of tools to be used. This paper describes the lip seal cutting and welding development programme performed at the VTT Technical Research Centre, Finland. Potential cutting and welding techniques are analyzed and compared. The development of the cutting, TIG and laser welding techniques on samples are presented. Effects of lip seal misalignments and optimization of the 2 welding processes are discussed. Finally, the manufacturing and test of the two 1.2 m × 1 m representative mock-ups are presented. The set-up and use of a robotic arm for the mock-up cutting and welding operations are also described.

  15. ITER lip seal welding and cutting developments

    Energy Technology Data Exchange (ETDEWEB)

    Levesy, B.; Cordier, J.J.; Jokinen, T. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Kujanpää, V.; Karhu, M. [VTT Technical Research Centre of Finland (Finland); Le Barbier, R. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Määttä, T. [VTT Technical Research Centre of Finland (Finland); Martins, J.P.; Utin, Y. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2015-10-15

    Highlights: • Different TIG and Laser welding techniques are tested. • Twin spot laser welding techniques is the best. • Limited heat input gives a stable weld pool in all positions. • Penetrations is achieved. • Lip seal welding and cutting with a robotic arm is successfully performed on a representative mock-up. - Abstract: The welded lip seals form part of the torus primary vacuum boundary in between the port plugs and the vacuum vessel, and are classified as Protection Important Component. In order to refurbish the port plugs or the in-vessel components, port plugs have to be removed from the machine. The lip seal design must enable up to ten opening of the vacuum vessel during the life time operation of the ITER machine. Therefore proven, remote reliable cutting and re-welding are essential, as these operations need to be performed in the port cells in a nuclear environment, where human presence will be restricted. Moreover, the combination of size of the components to be welded (∼10 m long vacuum compatible thin welds) and the congested environment close to the core of the machine constraint the type and size of tools to be used. This paper describes the lip seal cutting and welding development programme performed at the VTT Technical Research Centre, Finland. Potential cutting and welding techniques are analyzed and compared. The development of the cutting, TIG and laser welding techniques on samples are presented. Effects of lip seal misalignments and optimization of the 2 welding processes are discussed. Finally, the manufacturing and test of the two 1.2 m × 1 m representative mock-ups are presented. The set-up and use of a robotic arm for the mock-up cutting and welding operations are also described.

  16. Welding Technician

    Science.gov (United States)

    Smith, Ken

    2009-01-01

    About 95% of all manufactured goods in this country are welded or joined in some way. These welded products range in nature from bicycle handlebars and skyscrapers to bridges and race cars. The author discusses what students need to know about careers for welding technicians--wages, responsibilities, skills needed, career advancement…

  17. Fatique Resistant, Energy Efficient Welding Program, Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Egland, Keith; Ludewig, Howard

    2006-05-25

    The program scope was to affect the heat input and the resultant weld bead geometry by synchronizing robotic weave cycles with desired pulsed waveform shapes to develop process parameters relationships and optimized pulsed gas metal arc welding processes for welding fatique-critical structures of steel, high strength steel, and aluminum. Quality would be addressed by developing intelligent methods of weld measurement that accurately predict weld bead geometry from process information. This program was severely underfunded, and eventually terminated. The scope was redirected to investigate tandem narrow groove welding of steel butt joints during the one year of partial funding. A torch was designed and configured to perform a design of experiments of steel butt weld joints that validated the feasability of the process. An initial cost model estimated a 60% cost savings over conventional groove welding by eliminating the joint preparation and reducing the weld volume needed.

  18. Evolutionary Developmental Soft Robotics As a Framework to Study Intelligence and Adaptive Behavior in Animals and Plants

    Directory of Open Access Journals (Sweden)

    Francesco Corucci

    2017-07-01

    Full Text Available In this paper, a comprehensive methodology and simulation framework will be reviewed, designed in order to study the emergence of adaptive and intelligent behavior in generic soft-bodied creatures. By incorporating artificial evolutionary and developmental processes, the system allows to evolve complete creatures (brain, body, developmental properties, sensory, control system, etc. for different task environments. Whether the evolved creatures will resemble animals or plants is in general not known a priori, and depends on the specific task environment set up by the experimenter. In this regard, the system may offer a unique opportunity to explore differences and similarities between these two worlds. Different material properties can be simulated and optimized, from a continuum of soft/stiff materials, to the interconnection of heterogeneous structures, both found in animals and plants alike. The adopted genetic encoding and simulation environment are particularly suitable in order to evolve distributed sensory and control systems, which play a particularly important role in plants. After a general description of the system some case studies will be presented, focusing on the emergent properties of the evolved creatures. Particular emphasis will be on some unifying concepts that are thought to play an important role in the emergence of intelligent and adaptive behavior across both the animal and plant kingdoms, such as morphological computation and morphological developmental plasticity. Overall, with this paper, we hope to draw attention on set of tools, methodologies, ideas and results, which may be relevant to researchers interested in plant-inspired robotics and intelligence.

  19. Adaptation of a robot and tools for dismantling of a gas-cooled reactor

    International Nuclear Information System (INIS)

    Lewis, C.J.A.; Vibert, C.J.T.

    1989-01-01

    This report details the progress on a research programme to develop the techniques and design necessary to facilitate the use of commercially available industrial manipulator systems and cutting tools in nuclear environments, particularly that envisaged whilst decommissioning a gas-cooled reactor. The technology for the type of control and the machines to perform it already exist in the form of industrial-type robots. Development of the techniques for using these machines in a more operator-sensitive environment, together with the requirements of decontamination and radiation tolerance will enable them to be used in place of expensive purpose-built machines at a considerable cost saving. From this work it was possible to highlight the viability and associated costs of modifying a standard manipulator for use in decommissioning operations

  20. Friendly network robotics; Friendly network robotics

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This paper summarizes the research results on the friendly network robotics in fiscal 1996. This research assumes an android robot as an ultimate robot and the future robot system utilizing computer network technology. The robot aiming at human daily work activities in factories or under extreme environments is required to work under usual human work environments. The human robot with similar size, shape and functions to human being is desirable. Such robot having a head with two eyes, two ears and mouth can hold a conversation with human being, can walk with two legs by autonomous adaptive control, and has a behavior intelligence. Remote operation of such robot is also possible through high-speed computer network. As a key technology to use this robot under coexistence with human being, establishment of human coexistent robotics was studied. As network based robotics, use of robots connected with computer networks was also studied. In addition, the R-cube (R{sup 3}) plan (realtime remote control robot technology) was proposed. 82 refs., 86 figs., 12 tabs.

  1. Robotic intelligence kernel

    Science.gov (United States)

    Bruemmer, David J [Idaho Falls, ID

    2009-11-17

    A robot platform includes perceptors, locomotors, and a system controller. The system controller executes a robot intelligence kernel (RIK) that includes a multi-level architecture and a dynamic autonomy structure. The multi-level architecture includes a robot behavior level for defining robot behaviors, that incorporate robot attributes and a cognitive level for defining conduct modules that blend an adaptive interaction between predefined decision functions and the robot behaviors. The dynamic autonomy structure is configured for modifying a transaction capacity between an operator intervention and a robot initiative and may include multiple levels with at least a teleoperation mode configured to maximize the operator intervention and minimize the robot initiative and an autonomous mode configured to minimize the operator intervention and maximize the robot initiative. Within the RIK at least the cognitive level includes the dynamic autonomy structure.

  2. Resistance welding

    DEFF Research Database (Denmark)

    Bay, Niels; Zhang, Wenqi; Rasmussen, Mogens H.

    2003-01-01

    Resistance welding comprises not only the well known spot welding process but also more complex projection welding operations, where excessive plastic deformation of the weld point may occur. This enables the production of complex geometries and material combinations, which are often not possible...... to weld by traditional spot welding operations. Such joining processes are, however, not simple to develop due to the large number of parameters involved. Development has traditionally been carried out by large experimental investigations, but the development of a numerical programme system has changed...... this enabling prediction of the welding performance in details. The paper describes the programme in short and gives examples on industrial applications. Finally investigations of causes for failure in a complex industrial joint of two dissimilar metals are carried out combining numerical modelling...

  3. Automated Fuel Element Closure Welding System

    International Nuclear Information System (INIS)

    Wahlquist, D.R.

    1993-01-01

    The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout

  4. Laser welding engineering

    International Nuclear Information System (INIS)

    Bhieh, N. M.; El Eesawi, M. E.; Hashkel, A. E.

    2007-01-01

    Laser welding was in its early life used mainly for unusual applications where no other welding process would be suitable that was twenty five years ago. Today, laser welding is a fully developed part of the metal working industry, routinely producing welds for common items such as cigarette lighters, which springs, motor/transformer lamination, hermetic seals, battery and pacemaker cans and hybrid circuit packages. Yet very few manufacturing engineering have seriously considers employing lasers in their own operations. Why? There are many reasons, but a main one must be not acquainted with the operation and capabilities of a laser system. Other reasons, such as a relatively high initial cost and a concern about using lasers in the manufacturing environment, also are frequently cited, and the complexity of the component and flexibility of the light delivery system. Laser welding could be used in place of many different standard processes, such as resistance (spot or seam), submerged arc, RF induction, high-frequency resistance, ultrasonic and electronic and electron-beam. while each of these techniques has established an independent function in the manufacturing world, the flexible laser welding approach will operate efficiently and economically in many different applications. Its flexibility will even permit the welding system to be used for other machining function, such as drilling, scribing, sealing and serializing. In this article, we will look at how laser welding works and what benefits it can offer to manufacturing engineers. Some industry observers state that there are already 2,000 laser machine tools being used for cutting, welding and drilling and that the number could reach 30,000 over the next 15 years as manufacturing engineers become more aware of the capabilities of lasers [1). While most laser applications are dedicated to one product or process that involves high-volume, long-run manufacturing, the flexibility of a laser to supply energy to hard

  5. The development of an adaptive upper-limb stroke rehabilitation robotic system

    Science.gov (United States)

    2011-01-01

    Background Stroke is the primary cause of adult disability. To support this large population in recovery, robotic technologies are being developed to assist in the delivery of rehabilitation. This paper presents an automated system for a rehabilitation robotic device that guides stroke patients through an upper-limb reaching task. The system uses a decision theoretic model (a partially observable Markov decision process, or POMDP) as its primary engine for decision making. The POMDP allows the system to automatically modify exercise parameters to account for the specific needs and abilities of different individuals, and to use these parameters to take appropriate decisions about stroke rehabilitation exercises. Methods The performance of the system was evaluated by comparing the decisions made by the system with those of a human therapist. A single patient participant was paired up with a therapist participant for the duration of the study, for a total of six sessions. Each session was an hour long and occurred three times a week for two weeks. During each session, three steps were followed: (A) after the system made a decision, the therapist either agreed or disagreed with the decision made; (B) the researcher had the device execute the decision made by the therapist; (C) the patient then performed the reaching exercise. These parts were repeated in the order of A-B-C until the end of the session. Qualitative and quantitative question were asked at the end of each session and at the completion of the study for both participants. Results Overall, the therapist agreed with the system decisions approximately 65% of the time. In general, the therapist thought the system decisions were believable and could envision this system being used in both a clinical and home setting. The patient was satisfied with the system and would use this system as his/her primary method of rehabilitation. Conclusions The data collected in this study can only be used to provide insight into

  6. Sistem Kontrol Robot Arm 5 DOF Berbasis Pengenalan Pola Suara Menggunakan Mel-Frequency Cepstrum Coefficients (MFCC dan Adaptive Neuro-Fuzzy Inference System (ANFIS

    Directory of Open Access Journals (Sweden)

    WS Mada Sanjaya

    2016-12-01

    Full Text Available Telah dilakukan penelitian yang menggambarkan implementasi pengenalan pola suara untuk mengontrol gerak robot arm 5 DoF dalam mengambil dan menyimpan benda. Dalam penelitian ini metode yang digunakan adalah Mel-Frequency Cepstrum Coefficients (MFCC dan Adaptive Neuro-Fuzzy Inferense System (ANFIS. Metode MFCC digunakan untuk ekstraksi ciri sinyal suara, sedangkan ANFIS digunakan sebagai metode pembelajaran untuk pengenalan pola suara. Pada proses pembelajaran ANFIS data latih yang digunakan sebanyak 6 ciri. Data suara terlatih dan data suara tak terlatih digunakan untuk pengujian sistem pengenalan pola suara. Hasil pengujian menunjukkan tingkat keberhasilan, untuk data suara terlatih sebesar 87,77% dan data tak terlatih sebesar 78,53%. Sistem pengenalan pola suara ini telah diaplikasikan dengan baik untuk mengerakan robot arm 5 DoF berbasis mikrokontroler Arduino. Have been implemented of sound pattern recognition to control 5 DoF of Arm Robot to pick and place an object. In this research used Mel-Frequency Cepstrum Coefficients (MFCC and Adaptive Neuro-Fuzzy Interferense System (ANFIS methods. MFCC method used for features extraction of sound signal, meanwhile ANFIS used to learn sound pattern recognition. On ANFIS method data learning use 6 features. Trained and not trained data used to examine the system of sound pattern identification. The result show the succesfull level, for trained data 87.77% and for not trained data 78.53%. Sound pattern identification system was appliedto controlled 5 DoF arm robot based Arduino microcontroller.

  7. Robot-assisted adaptive training: custom force fields for teaching movement patterns.

    Science.gov (United States)

    Patton, James L; Mussa-Ivaldi, Ferdinando A

    2004-04-01

    Based on recent studies of neuro-adaptive control, we tested a new iterative algorithm to generate custom training forces to "trick" subjects into altering their target-directed reaching movements to a prechosen movement as an after-effect of adaptation. The prechosen movement goal, a sinusoidal-shaped path from start to end point, was never explicitly conveyed to the subject. We hypothesized that the adaptation would cause an alteration in the feedforward command that would result in the prechosen movement. Our results showed that when forces were suddenly removed after a training period of 330 movements, trajectories were significantly shifted toward the prechosen movement. However, de-adaptation occurred (i.e., the after-effect "washed out") in the 50-75 movements that followed the removal of the training forces. A second experiment suppressed vision of hand location and found a detectable reduction in the washout of after-effects, suggesting that visual feedback of error critically influences learning. A final experiment demonstrated that after-effects were also present in the neighborhood of training--44% of original directional shift was seen in adjacent, unpracticed movement directions to targets that were 60 degrees different from the targets used for training. These results demonstrate the potential for these methods for teaching motor skills and for neuro-rehabilitation of brain-injured patients. This is a form of "implicit learning," because unlike explicit training methods, subjects learn movements with minimal instructions, no knowledge of, and little attention to the trajectory.

  8. Razor clam to RoboClam: burrowing drag reduction mechanisms and their robotic adaptation

    International Nuclear Information System (INIS)

    Winter, A G; V; Dorsch, D S; Slocum, A H; Hosoi, A E; Deits, R L H

    2014-01-01

    Estimates based on the strength, size, and shape of the Atlantic razor clam (Ensis directus) indicate that the animal's burrow depth should be physically limited to a few centimeters; yet razor clams can dig as deep as 70 cm. By measuring soil deformations around burrowing E. directus, we have found the animal reduces drag by contracting its valves to initially fail, and then fluidize, the surrounding substrate. The characteristic contraction time to achieve fluidization can be calculated directly from soil properties. The geometry of the fluidized zone is dictated by two commonly-measured geotechnical parameters: coefficient of lateral earth pressure and friction angle. Calculations using full ranges for both parameters indicate that the fluidized zone is a local effect, occurring between 1–5 body radii away from the animal. The energy associated with motion through fluidized substrate—characterized by a depth-independent density and viscosity—scales linearly with depth. In contrast, moving through static soil requires energy that scales with depth squared. For E. directus, this translates to a 10X reduction in the energy required to reach observed burrow depths. For engineers, localized fluidization offers a mechanically simple and purely kinematic method to dramatically reduce energy costs associated with digging. This concept is demonstrated with RoboClam, an E. directus-inspired robot. Using a genetic algorithm to find optimal digging kinematics, RoboClam has achieved localized fluidization burrowing performance comparable to that of the animal, with a linear energy-depth relationship, in both idealized granular glass beads and E. directus' native cohesive mudflat habitat. (paper)

  9. A 1993 review of welding in Japan

    Science.gov (United States)

    1994-07-01

    This paper describes a prospect on Japanese welding technologies available in 1993. Amid the increasing research publications on non-ferrous metals as structural materials, publications are also increasing on steel materials as to their fracture and welding mechanics, and structural control. Studies are being made on ceramics with respect to its bonding, interface reaction mechanisms, and mechanical characteristics. The paper describes the progress and improvement in conventional technologies in welding and cutting processes. Especially active is the study on solid face welding such as pressure welding and diffusion. A considerable decrease is seen in reports on thermal spraying. The paper also introduces surface processing and hydrostatic pressure processing as new processing techniques. In the area of welding devices, practical use of arc welding robots has come to near a completion stage. Technological development and cost reduction are indispensable to transfer to visual sensing with a higher intelligence level. With respect to the performance of joints, a large number of research has been reported on welding deformation and residual stress. The paper also dwells on corrosion resistance and welding cracks. Quality assurance, inspection, and related standards are described. Details are given on application of welding to different industrial fields.

  10. Upgraded HFIR Fuel Element Welding System

    International Nuclear Information System (INIS)

    Sease, John D.

    2010-01-01

    The welding of aluminum-clad fuel plates into aluminum alloy 6061 side plate tubing is a unique design feature of the High Flux Isotope Reactor (HFIR) fuel assemblies as 101 full-penetration circumferential gas metal arc welds (GMAW) are required in the fabrication of each assembly. In a HFIR fuel assembly, 540 aluminum-clad fuel plates are assembled into two nested annular fuel elements 610 mm (24-inches) long. The welding process for the HFIR fuel elements was developed in the early 1960 s and about 450 HFIR fuel assemblies have been successfully welded using the GMAW process qualified in the 1960 s. In recent years because of the degradation of the electronic and mechanical components in the old HFIR welding system, reportable defects in plate attachment or adapter welds have been present in almost all completed fuel assemblies. In October 2008, a contract was awarded to AMET, Inc., of Rexburg, Idaho, to replace the old welding equipment with standard commercially available welding components to the maximum extent possible while maintaining the qualified HFIR welding process. The upgraded HFIR welding system represents a major improvement in the welding system used in welding HFIR fuel elements for the previous 40 years. In this upgrade, the new inner GMAW torch is a significant advancement over the original inner GMAW torch previously used. The innovative breakthrough in the new inner welding torch design is the way the direction of the cast in the 0.762 mm (0.030-inch) diameter aluminum weld wire is changed so that the weld wire emerging from the contact tip is straight in the plane perpendicular to the welding direction without creating any significant drag resistance in the feeding of the weld wire.

  11. Soldadura (Welding). Spanish Translations for Welding.

    Science.gov (United States)

    Hohhertz, Durwin

    Thirty transparency masters with Spanish subtitles for key words are provided for a welding/general mechanical repair course. The transparency masters are on such topics as oxyacetylene welding; oxyacetylene welding equipment; welding safety; different types of welds; braze welding; cutting torches; cutting with a torch; protective equipment; arc…

  12. WELDING TORCH

    Science.gov (United States)

    Correy, T.B.

    1961-10-01

    A welding torch into which water and inert gas are piped separately for cooling and for providing a suitable gaseous atmosphere is described. A welding electrode is clamped in the torch by a removable collet sleeve and a removable collet head. Replacement of the sleeve and head with larger or smaller sleeve and head permits a larger or smaller welding electrode to be substituted on the torch. (AEC)

  13. Welding stresses

    International Nuclear Information System (INIS)

    Poirier, J.; Barbe, B.; Jolly, N.

    1976-01-01

    The aim is to show how internal stresses are generated and to fix the orders of magnitude. A realistic case, the vertical welding of thick plates free to move one against the other, is described and the deformations and stresses are analyzed. The mathematical model UEDA, which accounts for the elastic modulus, the yield strength and the expansion coefficient of the metal with temperature, is presented. The hypotheses and results given apply only to the instantaneous welding of a welded plate and to a plate welded by a moving electrode [fr

  14. An Adaptable Robot Vision System Performing Manipulation Actions With Flexible Objects

    DEFF Research Database (Denmark)

    Bodenhagen, Leon; Fugl, Andreas R.; Jordt, Andreas

    2014-01-01

    system should be viewed as a library of new technologies that have been proven to work in close to industrial conditions. As a rather basic, but necessary part, we provide a technology for determining the shape of the object when passing on, e. g., a conveyor belt prior to being handled. The main......This paper describes an adaptable system which is able to perform manipulation operations (such as Peg-in-Hole or Laying-Down actions) with flexible objects. As such objects easily change their shape significantly during the execution of an action, traditional strategies, e. g., for solve path......, operating in real-time. Simulations have been used to bootstrap the learning of optimal actions, which are subsequently improved through real-world executions. To achieve reproducible results, we demonstrate this for casted silicone test objects of regular shape. Note to Practitioners-The aim of this work...

  15. Adaptive gaze stabilization through cerebellar internal models in a humanoid robot

    DEFF Research Database (Denmark)

    Vannucci, Lorenzo; Tolu, Silvia; Falotico, Egidio

    2016-01-01

    Two main classes of reflexes relying on the vestibular system are involved in the stabilization of the human gaze: The vestibulocollic reflex (VCR), which stabilizes the head in space and the vestibulo-ocular reflex (VOR), which stabilizes the visual axis to minimize retinal image motion. The VOR...... on the coordination of VCR and VOR and OKR. The model, inspired on neuroscientific cerebellar theories, is provided with learning and adaptation capabilities based on internal models. Tests on a simulated humanoid platform confirm the effectiveness of our approach....... works in conjunction with the opto-kinetic reflex (OKR), which is a visual feedback mechanism for moving the eye at the same speed as the observed scene. Together they keep the image stationary on the retina. In this work we present the first complete model of gaze stabilization based...

  16. Adaptive Iterated Extended Kalman Filter and Its Application to Autonomous Integrated Navigation for Indoor Robot

    Directory of Open Access Journals (Sweden)

    Yuan Xu

    2014-01-01

    Full Text Available As the core of the integrated navigation system, the data fusion algorithm should be designed seriously. In order to improve the accuracy of data fusion, this work proposed an adaptive iterated extended Kalman (AIEKF which used the noise statistics estimator in the iterated extended Kalman (IEKF, and then AIEKF is used to deal with the nonlinear problem in the inertial navigation systems (INS/wireless sensors networks (WSNs-integrated navigation system. Practical test has been done to evaluate the performance of the proposed method. The results show that the proposed method is effective to reduce the mean root-mean-square error (RMSE of position by about 92.53%, 67.93%, 55.97%, and 30.09% compared with the INS only, WSN, EKF, and IEKF.

  17. Robustly stable adaptive control of a tandem of master-slave robotic manipulators with force reflection by using a multiestimation scheme.

    Science.gov (United States)

    Ibeas, Asier; de la Sen, Manuel

    2006-10-01

    The problem of controlling a tandem of robotic manipulators composing a teleoperation system with force reflection is addressed in this paper. The final objective of this paper is twofold: 1) to design a robust control law capable of ensuring closed-loop stability for robots with uncertainties and 2) to use the so-obtained control law to improve the tracking of each robot to its corresponding reference model in comparison with previously existing controllers when the slave is interacting with the obstacle. In this way, a multiestimation-based adaptive controller is proposed. Thus, the master robot is able to follow more accurately the constrained motion defined by the slave when interacting with an obstacle than when a single-estimation-based controller is used, improving the transparency property of the teleoperation scheme. The closed-loop stability is guaranteed if a minimum residence time, which might be updated online when unknown, between different controller parameterizations is respected. Furthermore, the analysis of the teleoperation and stability capabilities of the overall scheme is carried out. Finally, some simulation examples showing the working of the multiestimation scheme complete this paper.

  18. Adaptive scallop height tool path generation for robot-based incremental sheet metal forming

    Science.gov (United States)

    Seim, Patrick; Möllensiep, Dennis; Störkle, Denis Daniel; Thyssen, Lars; Kuhlenkötter, Bernd

    2016-10-01

    Incremental sheet metal forming is an emerging process for the production of individualized products or prototypes in low batch sizes and with short times to market. In these processes, the desired shape is produced by the incremental inward motion of the workpiece-independent forming tool in depth direction and its movement along the contour in lateral direction. Based on this shape production, the tool path generation is a key factor on e.g. the resulting geometric accuracy, the resulting surface quality, and the working time. This paper presents an innovative tool path generation based on a commercial milling CAM package considering the surface quality and working time. This approach offers the ability to define a specific scallop height as an indicator of the surface quality for specific faces of a component. Moreover, it decreases the required working time for the production of the entire component compared to the use of a commercial software package without this adaptive approach. Different forming experiments have been performed to verify the newly developed tool path generation. Mainly, this approach serves to solve the existing conflict of combining the working time and the surface quality within the process of incremental sheet metal forming.

  19. WELDING METHOD

    Science.gov (United States)

    Cornell, A.A.; Dunbar, J.V.; Ruffner, J.H.

    1959-09-29

    A semi-automatic method is described for the weld joining of pipes and fittings which utilizes the inert gasshielded consumable electrode electric arc welding technique, comprising laying down the root pass at a first peripheral velocity and thereafter laying down the filler passes over the root pass necessary to complete the weld by revolving the pipes and fittings at a second peripheral velocity different from the first peripheral velocity, maintaining the welding head in a fixed position as to the specific direction of revolution, while the longitudinal axis of the welding head is disposed angularly in the direction of revolution at amounts between twenty minutas and about four degrees from the first position.

  20. Exploratorium: Robots.

    Science.gov (United States)

    Brand, Judith, Ed.

    2002-01-01

    This issue of Exploratorium Magazine focuses on the topic robotics. It explains how to make a vibrating robotic bug and features articles on robots. Contents include: (1) "Where Robot Mice and Robot Men Run Round in Robot Towns" (Ray Bradbury); (2) "Robots at Work" (Jake Widman); (3) "Make a Vibrating Robotic Bug" (Modesto Tamez); (4) "The Robot…

  1. Austenitic stainless steel weld inspection

    International Nuclear Information System (INIS)

    Mech, S.J.; Emmons, J.S.; Michaels, T.E.

    1978-01-01

    Analytical techniques applied to ultrasonic waveforms obtained from inspection of austenitic stainless steel welds are described. Experimental results obtained from a variety of geometric and defect reflectors are presented. Specifically, frequency analyses parameters, such as simple moments of the power spectrum, cross-correlation techniques, and adaptive learning network analysis, all represent improvements over conventional time domain analysis of ultrasonic waveforms. Results for each of these methods are presented, and the overall inspection difficulties of austenitic stainless steel welds are discussed

  2. Repair welding and online radiography

    International Nuclear Information System (INIS)

    Nuding, W.; Grimm, R.; Link, R.; Schroeder, P.; Schroeder, G.

    1990-01-01

    The status of a joint project is reported, which is to develop a computerized testing and welding system for repair work in turbine blades. An X-ray radiographic testing device consisting of microfocus tube, manipulator and image processing system, is modified for this purpose so as to offer a greater number of image points scanned for image processing, and to thus achieve a better resolution for reliable detection of even very small defects. The consistency of the X-ray tube performance, which is a pre-requisite for automation, is to be achieved by a wa tercooled, high-duty tube head. The recording of defect coordinates in the repair zone is done for input into a welding robot to be developed by other partners in the project, so as to allow automated welding work. (orig.) [de

  3. Auto-adaptative Robot-aided Therapy based in 3D Virtual Tasks controlled by a Supervised and Dynamic Neuro-Fuzzy System

    Directory of Open Access Journals (Sweden)

    Luis Daniel Lledó

    2015-03-01

    Full Text Available This paper presents an application formed by a classification method based on the architecture of ART neural network (Adaptive Resonance Theory and the Fuzzy Set Theory to classify physiological reactions in order to automatically and dynamically adapt a robot-assisted rehabilitation therapy to the patient needs, using a three-dimensional task in a virtual reality system. Firstly, the mathematical and structural model of the neuro-fuzzy classification method is described together with the signal and training data acquisition. Then, the virtual designed task with physics behavior and its development procedure are explained. Finally, the general architecture of the experimentation for the auto-adaptive therapy is presented using the classification method with the virtual reality exercise.

  4. Ultrasonic diagnosis of spot welding in thin plates

    International Nuclear Information System (INIS)

    Kim, No You; Hong, Min Sung

    2005-01-01

    Spot welding widely used in automotive and aerospace industries has made it possible to produce more precise and smaller electric part by robotization and systemization of welding process. The quality of welding depends upon the size of nugget between the overlapped steel plates. Recently, the thickness of the steel plates becomes much thinner and hence, it introduces the smaller size of nugget. Therefore, it is necessary to develop the criterion to evaluate the quality of weld in order to obtain the optimal welding conditions for the better performance. In this paper, a thin steel plates, 0.1 mm through 0.3 mm thickness, have been spot-welded at different welding conditions and the nugget sizes are examined by defocused scanning microscopy. The relationships between nugget sizes and weldability have been investigated experimentally. The result of ultrasonic technique shows the good agreement with that of the tensile test.

  5. Testing of electron beam welding by ultrasonic transducers

    International Nuclear Information System (INIS)

    Touffait, A.-M.; Roule, M.; Destribats, M.-T.

    1978-01-01

    Focalized ultrasonic testing is well adapted to the study of electron beam welding. This type of welding leads to narrow weld beads and to small dimension testing zones. Focalized transducers can be used enabling very small defects to be detected [fr

  6. Intelligent sensing and control of gas metal arc welding

    International Nuclear Information System (INIS)

    Smartt, H.B.; Johnson, J.A.

    1993-01-01

    Intelligent sensing and control is a multidisciplinary approach that attempts to build adequate sensing capability, knowledge of process physics, control capability, and welding engineering into the welding system such that the welding machine is aware of the state of the weld and knows how to make a good weld. The sensing and control technology should reduce the burden on the welder and welding engineer while providing the great adaptability needed to accommodate the variability found in the production world. This approach, accomplished with application of AI techniques, breaks the tradition of separate development of procedure and control technology

  7. Welding process

    International Nuclear Information System (INIS)

    Abdul Nassir Ibrahim; Azali Muhammad; Ab. Razak Hamzah; Abd. Aziz Mohamed; Mohamad Pauzi Ismail

    2008-01-01

    For the final chapter of this book, there is basic introduction on welding process. The good radiography must know somehow on welding process so that they can know what kind of welding that must rejected or not. All of the exposure technique that mention in earlier chapter almost applicable in this field because welding process is critical problem if there is no inspection will be done. So, for this chapter, all the discontinuity that usually appeared will be discussed and there is another discontinuity maybe not to important and do not give big impact if found it, do not described here. On top of that, the decision to accept or reject based on code, standard and specification that agreed by both to make sure that decision that agreed is corrected and more meaningful.

  8. DESIGN OF A WELDING AND INSPECTION SYSTEM FOR WASTE STORAGE CLOSURE

    International Nuclear Information System (INIS)

    H.B. Smartt; A.D. Watkins; D.P. Pace; R.J. Bitsoi; E.D. Larsen T.R. McJunkin; C.R. Tolle

    2005-01-01

    This work reported here was done to provide a conceptual design for a robotic welding and inspection system for the Yucca Mountain Repository waste package closure system. The welding and inspection system is intended to make the various closure welds that seal and/or structurally join the lids to the waste package vessels. The welding and inspection system will also perform surface and volumetric inspections of the various closure welds and has the means to repair closure welds, if required. The system is designed to perform these various activities remotely, without the necessity of having personnel in the closure cell

  9. A Weld Position Recognition Method Based on Directional and Structured Light Information Fusion in Multi-Layer/Multi-Pass Welding

    Directory of Open Access Journals (Sweden)

    Jinle Zeng

    2018-01-01

    Full Text Available Multi-layer/multi-pass welding (MLMPW technology is widely used in the energy industry to join thick components. During automatic welding using robots or other actuators, it is very important to recognize the actual weld pass position using visual methods, which can then be used not only to perform reasonable path planning for actuators, but also to correct any deviations between the welding torch and the weld pass position in real time. However, due to the small geometrical differences between adjacent weld passes, existing weld position recognition technologies such as structured light methods are not suitable for weld position detection in MLMPW. This paper proposes a novel method for weld position detection, which fuses various kinds of information in MLMPW. First, a synchronous acquisition method is developed to obtain various kinds of visual information when directional light and structured light sources are on, respectively. Then, interferences are eliminated by fusing adjacent images. Finally, the information from directional and structured light images is fused to obtain the 3D positions of the weld passes. Experiment results show that each process can be done in 30 ms and the deviation is less than 0.6 mm. The proposed method can be used for automatic path planning and seam tracking in the robotic MLMPW process as well as electron beam freeform fabrication process.

  10. A Weld Position Recognition Method Based on Directional and Structured Light Information Fusion in Multi-Layer/Multi-Pass Welding.

    Science.gov (United States)

    Zeng, Jinle; Chang, Baohua; Du, Dong; Wang, Li; Chang, Shuhe; Peng, Guodong; Wang, Wenzhu

    2018-01-05

    Multi-layer/multi-pass welding (MLMPW) technology is widely used in the energy industry to join thick components. During automatic welding using robots or other actuators, it is very important to recognize the actual weld pass position using visual methods, which can then be used not only to perform reasonable path planning for actuators, but also to correct any deviations between the welding torch and the weld pass position in real time. However, due to the small geometrical differences between adjacent weld passes, existing weld position recognition technologies such as structured light methods are not suitable for weld position detection in MLMPW. This paper proposes a novel method for weld position detection, which fuses various kinds of information in MLMPW. First, a synchronous acquisition method is developed to obtain various kinds of visual information when directional light and structured light sources are on, respectively. Then, interferences are eliminated by fusing adjacent images. Finally, the information from directional and structured light images is fused to obtain the 3D positions of the weld passes. Experiment results show that each process can be done in 30 ms and the deviation is less than 0.6 mm. The proposed method can be used for automatic path planning and seam tracking in the robotic MLMPW process as well as electron beam freeform fabrication process.

  11. Optimization of the A-TIG welding for stainless steels

    Science.gov (United States)

    Jurica, M.; Kožuh, Z.; Garašić, I.; Bušić, M.

    2018-03-01

    The paper presents the influence of the activation flux and shielding gas on tungsten inert gas (A-TIG) welding of the stainless steel. In introduction part, duplex stainless steel was analysed. The A-TIG process was explained and the possibility of welding stainless steels using the A-TIG process to maximize productivity and the cost-effectiveness of welded structures was presented. In the experimental part duplex, 7 mm thick stainless steel has been welded in butt joint. The influence of activation flux chemical composition upon the weld penetration has been investigated prior the welding. The welding process was performed by a robot with TIG equipment. With selected A-TIG welding technology preparation of plates and consumption of filler material (containing Cr, Ni and Mn) have been avoided. Specimens sectioned from the produced welds have been subjected to tensile strength test, macrostructure analysis and corrosion resistance analysis. The results have confirmed that this type of stainless steel can be welded without edge preparation and addition of filler material containing critical raw materials as Cr, Ni and Mn when the following welding parameters are set: current 200 A, welding speed 9,1 cm/min, heat input 1,2 kJ/mm and specific activation flux is used.

  12. Welding parameter optimization of alloy material by friction stir welding using Taguchi approach and design of experiments

    Science.gov (United States)

    Karwande, Amit H.; Rao, Seeram Srinivasa

    2018-04-01

    Friction stir welding (FSW) a welding process in which metals are joint by melting them at their solid state. In different engineering areas such as civil, mechanical, naval and aeronautical engineering beams are widely used of the magnesium alloys for different applications and that are joined by conventional inert gas welding process. Magnesium metal has less density and low melting point for that reason large heat generation in the common welding process so its necessity to adapt new welding process. FSW process increases the weld quality which observed under various mechanical testing by using different tool size.

  13. Syllabus in Trade Welding.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The syllabus outlines material for a course two academic years in length (minimum two and one-half hours daily experience) leading to entry-level occupational ability in several welding trade areas. Fourteen units covering are welding, gas welding, oxyacetylene welding, cutting, nonfusion processes, inert gas shielded-arc welding, welding cast…

  14. Adaptation to Elastic Loads and BMI Robot Controls During Rat Locomotion examined with Point-Process GLMs.

    Directory of Open Access Journals (Sweden)

    Weiguo eSong

    2015-04-01

    Full Text Available Currently little is known about how a mechanically coupled BMI system’s actions are integrated into ongoing body dynamics. We tested a locomotor task augmented with a BMI system driving a robot mechanically interacting with a rat under three conditions: control locomotion (BL, ‘simple elastic load’ (E and ‘BMI with elastic load’ (BMI/E. The effect of the BMI was to allow compensation of the elastic load as a function of the neural drive. Neurons recorded here were close to one another in cortex, all within a 200 micron diameter horizontal distance of one another. The interactions of these close assemblies of neurons may differ from those among neurons at longer distances in BMI tasks and thus are important to explore. A point process generalized linear model (GLM, was used to examine connectivity at two different binning timescales (1ms vs. 10ms. We used GLM models to fit non-Poisson neural dynamics solely using other neurons’ prior neural activity as covariates. Models at different timescales were compared based on Kolmogorov-Smirnov (KS goodness-of-fit and parsimony. About 15% of cells with non-Poisson firing were well fitted with the neuron-to-neuron models alone. More such cells were fitted at the 1ms binning than 10ms. Positive connection parameters (‘excitation’ ~70% exceeded negative parameters (‘inhibition’ ~30%. Significant connectivity changes in the GLM determined networks of well-fitted neurons occurred between the conditions. However, a common core of connections comprising at least ~15% of connections persisted between any two of the three conditions. Significantly almost twice as many connections were in common between the two load conditions (~27%, compared to between either load condition and the baseline. This local point process GLM identified neural correlation structure and the changes seen across task conditions in the rats in this neural subset may be intrinsic to cortex or due to feedback and input

  15. Automatic weld joint X-ray inspection

    International Nuclear Information System (INIS)

    Richter, H.U.; Linke, D.; Siems, K.D.; Kruse, H.; Schuetze, E.

    1990-01-01

    A gantry mounted robotic x-ray inspection unit has been developed for the series testing of small and medium sized welded components (pipe bends and nozzles). The unit features computer controlled positioning of the x-ray tube and x-ray image amplifier. Image quality classes 2 and even 1 could be achieved without difficulty. (author)

  16. Automatization and mechanization of welding in nuclear engineering

    Energy Technology Data Exchange (ETDEWEB)

    Shul' ma, I E; Kupin, N V

    1986-02-01

    The state of welding and cladding works, which constitute more than 12% of total labour content of NPP equipment production, is described. Special attention is paid to a considerable part of manual labour in the processes of thermal cutting and welding of joints inside the vessels. The necessity of perspective technology introduction is pointed out. It means, in particular, the introduction of technological complex robotics for automatic welding of pipes with tube plates in heat exchanger, the mechanization of cladding processes for sealing surfaces of locking equipment, facility equipment for the welding of steam generator vessels to bottoms by means of preliminary and concomitant heating devices.

  17. Automatization and mechanization of welding in nuclear engineering

    International Nuclear Information System (INIS)

    Shul'ma, I.E.; Kupin, N.V.

    1986-01-01

    The state of welding and cladding works, which constitute more than 12% of total labour content of NPP equipment production, is described. Special attention is paid to a considerable part of manual labour in the processes of thermal cutting and welding of joints inside the vessels. The necessity of perspective technology introduction is pointed out. It means, in particular, the introduction of technological complex robotics for automatic welding of pipes with tube plates in heat exchanger, the mechanization of cladding processes for sealing surfaces of locking equipment, facility equipment for the welding of steam generator vessels to bottoms by means of preliminary and concomitant heating devices

  18. A dosimetric comparison of real-time adaptive and non-adaptive radiotherapy: A multi-institutional study encompassing robotic, gimbaled, multileaf collimator and couch tracking

    DEFF Research Database (Denmark)

    Colvill, Emma; Booth, Jeremy; Nill, Simeon

    2016-01-01

    AND MATERIALS: Ten institutions with robotic(2), gimbaled(2), MLC(4) or couch tracking(2) used common materials including CT and structure sets, motion traces and planning protocols to create a lung and a prostate plan. For each motion trace, the plan was delivered twice to a moving dosimeter; with and without...

  19. Future use of robots in the automotive industry

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, M P

    1982-01-01

    The future will see a dramatic increase in the number of robots used in the automotive industry. Well established applications, such as resistance spot welding, will continue to grow in the short term. Longer term, the much wider use of structural adhesives will supplant the spot welding process with robots applying the adhesives. Practical perception systems will enhance robot performance in arc welding, grinding, fettling, seam sealing and assembly operations, leading again to robot growth as vital elements of truly flexible manufacturing systems (FMS). A major robotic impact will be made in automotive paint shops as the need to conserve energy increases. The development of alternative painting materials, offering improved performance will add further impetus. Robotics of the future will progressively move to a CAD/CAM orientated data base, offering off-line programming capability, which together with essential inspection elements, will provide the means for totally automatic manufacture.

  20. Robot Actors, Robot Dramaturgies

    DEFF Research Database (Denmark)

    Jochum, Elizabeth

    This paper considers the use of tele-operated robots in live performance. Robots and performance have long been linked, from the working androids and automata staged in popular exhibitions during the nineteenth century and the robots featured at Cybernetic Serendipity (1968) and the World Expo...

  1. Perspectives of construction robots

    Science.gov (United States)

    Stepanov, M. A.; Gridchin, A. M.

    2018-03-01

    This article is an overview of construction robots features, based on formulating the list of requirements for different types of construction robots in relation to different types of construction works.. It describes a variety of construction works and ways to construct new or to adapt existing robot designs for a construction process. Also, it shows the prospects of AI-controlled machines, implementation of automated control systems and networks on construction sites. In the end, different ways to develop and improve, including ecological aspect, the construction process through the wide robotization, creating of data communication networks and, in perspective, establishing of fully AI-controlled construction complex are formulated.

  2. Soft-Material Robotics

    OpenAIRE

    Wang, L; Nurzaman, SG; Iida, Fumiya

    2017-01-01

    There has been a boost of research activities in robotics using soft materials in the past ten years. It is expected that the use and control of soft materials can help realize robotic systems that are safer, cheaper, and more adaptable than the level that the conventional rigid-material robots can achieve. Contrary to a number of existing review and position papers on soft-material robotics, which mostly present case studies and/or discuss trends and challenges, the review focuses on the fun...

  3. Soft computing in advanced robotics

    CERN Document Server

    Kobayashi, Ichiro; Kim, Euntai

    2014-01-01

    Intelligent system and robotics are inevitably bound up; intelligent robots makes embodiment of system integration by using the intelligent systems. We can figure out that intelligent systems are to cell units, while intelligent robots are to body components. The two technologies have been synchronized in progress. Making leverage of the robotics and intelligent systems, applications cover boundlessly the range from our daily life to space station; manufacturing, healthcare, environment, energy, education, personal assistance, logistics. This book aims at presenting the research results in relevance with intelligent robotics technology. We propose to researchers and practitioners some methods to advance the intelligent systems and apply them to advanced robotics technology. This book consists of 10 contributions that feature mobile robots, robot emotion, electric power steering, multi-agent, fuzzy visual navigation, adaptive network-based fuzzy inference system, swarm EKF localization and inspection robot. Th...

  4. Robotic architectures

    CSIR Research Space (South Africa)

    Mtshali, M

    2010-01-01

    Full Text Available In the development of mobile robotic systems, a robotic architecture plays a crucial role in interconnecting all the sub-systems and controlling the system. The design of robotic architectures for mobile autonomous robots is a challenging...

  5. Robot Games for Elderly

    DEFF Research Database (Denmark)

    Hansen, Søren Tranberg

    2011-01-01

    improve a person’s overall health, and this thesis investigates how games based on an autonomous, mobile robot platform, can be used to motivate elderly to move physically while playing. The focus of the investigation is on the development of games for an autonomous, mobile robot based on algorithms using...... spatio-temporal information about player behaviour - more specifically, I investigate three types of games each using a different control strategy. The first game is based on basic robot control which allows the robot to detect and follow a person. A field study in a rehabilitation centre and a nursing....... The robot facilitates interaction, and the study suggests that robot based games potentially can be used for training balance and orientation. The second game consists in an adaptive game algorithm which gradually adjusts the game challenge to the mobility skills of the player based on spatio...

  6. Intelligent controller of a flexible hybrid robot machine for ITER assembly and maintenance

    International Nuclear Information System (INIS)

    Al-saedi, Mazin I.; Wu, Huapeng; Handroos, Heikki

    2014-01-01

    Highlights: • Studying flexible multibody dynamic of hybrid parallel robot. • Investigating fuzzy-PD controller to control a hybrid flexible hydraulically driven robot. • Investigating ANFIS-PD controller to control a hybrid flexible robot. Compare to traditional PID this method gives better performance. • Using the equilibrium of reaction forces between the parallel and serial parts of hybrid robot to control the serial part hydraulically driven. - Abstract: The assembly and maintenance of International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is highly challenging since the tasks performed by the robot involve welding, material handling, and machine cutting from inside the VV. To fulfill the tasks in ITER application, this paper presents a hybrid redundant manipulator with four DOFs provided by serial kinematic axes and six DOFs by parallel mechanism. Thus, in machining, to achieve greater end-effector trajectory tracking accuracy for surface quality, a robust control of the actuators for the flexible link has to be deduced. In this paper, the intelligent control of a hydraulically driven parallel robot part based on the dynamic model and two control schemes have been investigated: (1) fuzzy-PID self tuning controller composed of the conventional PID control and with fuzzy logic; (2) adaptive neuro-fuzzy inference system-PID (ANFIS-PID) self tuning of the gains of the PID controller, which are implemented independently to control each hydraulic cylinder of the parallel robot based on rod position predictions. The obtained results of the fuzzy-PID and ANFIS-PID self tuning controller can reduce more tracking errors than the conventional PID controller. Subsequently, the serial component of the hybrid robot can be analyzed using the equilibrium of reaction forces at the universal joint connections of the hexa-element. To achieve precise positional control of the end effector for maximum precision machining, the hydraulic cylinder should

  7. Intelligent controller of a flexible hybrid robot machine for ITER assembly and maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Al-saedi, Mazin I., E-mail: mazin.al-saedi@lut.fi; Wu, Huapeng; Handroos, Heikki

    2014-10-15

    Highlights: • Studying flexible multibody dynamic of hybrid parallel robot. • Investigating fuzzy-PD controller to control a hybrid flexible hydraulically driven robot. • Investigating ANFIS-PD controller to control a hybrid flexible robot. Compare to traditional PID this method gives better performance. • Using the equilibrium of reaction forces between the parallel and serial parts of hybrid robot to control the serial part hydraulically driven. - Abstract: The assembly and maintenance of International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV) is highly challenging since the tasks performed by the robot involve welding, material handling, and machine cutting from inside the VV. To fulfill the tasks in ITER application, this paper presents a hybrid redundant manipulator with four DOFs provided by serial kinematic axes and six DOFs by parallel mechanism. Thus, in machining, to achieve greater end-effector trajectory tracking accuracy for surface quality, a robust control of the actuators for the flexible link has to be deduced. In this paper, the intelligent control of a hydraulically driven parallel robot part based on the dynamic model and two control schemes have been investigated: (1) fuzzy-PID self tuning controller composed of the conventional PID control and with fuzzy logic; (2) adaptive neuro-fuzzy inference system-PID (ANFIS-PID) self tuning of the gains of the PID controller, which are implemented independently to control each hydraulic cylinder of the parallel robot based on rod position predictions. The obtained results of the fuzzy-PID and ANFIS-PID self tuning controller can reduce more tracking errors than the conventional PID controller. Subsequently, the serial component of the hybrid robot can be analyzed using the equilibrium of reaction forces at the universal joint connections of the hexa-element. To achieve precise positional control of the end effector for maximum precision machining, the hydraulic cylinder should

  8. Welding template

    International Nuclear Information System (INIS)

    Ben Venue, R.J. of.

    1976-01-01

    A welding template is described which is used to weld strip material into a cellular grid structure for the accommodation of fuel elements in a nuclear reactor. On a base plate the template carries a multitude of cylindrical pins whose upper half is narrower than the bottom half and only one of which is attached to the base plate. The others are arrested in a hexagonal array by oblong webs clamped together by chuck jaws which can be secured by means of screws. The parts are ground very accurately. The template according to the invention is very easy to make. (UWI) [de

  9. Spatial Programming for Industrial Robots through Task Demonstration

    Directory of Open Access Journals (Sweden)

    Jens Lambrecht

    2013-05-01

    Full Text Available Abstract We present an intuitive system for the programming of industrial robots using markerless gesture recognition and mobile augmented reality in terms of programming by demonstration. The approach covers gesture-based task definition and adaption by human demonstration, as well as task evaluation through augmented reality. A 3D motion tracking system and a handheld device establish the basis for the presented spatial programming system. In this publication, we present a prototype toward the programming of an assembly sequence consisting of several pick-and-place tasks. A scene reconstruction provides pose estimation of known objects with the help of the 2D camera of the handheld. Therefore, the programmer is able to define the program through natural bare-hand manipulation of these objects with the help of direct visual feedback in the augmented reality application. The program can be adapted by gestures and transmitted subsequently to an arbitrary industrial robot controller using a unified interface. Finally, we discuss an application of the presented spatial programming approach toward robot-based welding tasks.

  10. Static stiffness modeling of a novel hybrid redundant robot machine

    International Nuclear Information System (INIS)

    Li Ming; Wu Huapeng; Handroos, Heikki

    2011-01-01

    This paper presents a modeling method to study the stiffness of a hybrid serial-parallel robot IWR (Intersector Welding Robot) for the assembly of ITER vacuum vessel. The stiffness matrix of the basic element in the robot is evaluated using matrix structural analysis (MSA); the stiffness of the parallel mechanism is investigated by taking account of the deformations of both hydraulic limbs and joints; the stiffness of the whole integrated robot is evaluated by employing the virtual joint method and the principle of virtual work. The obtained stiffness model of the hybrid robot is analytical and the deformation results of the robot workspace under certain external load are presented.

  11. Automatic Specialization of Modular Robot Limbs

    Data.gov (United States)

    National Aeronautics and Space Administration — Modular robotic systems have the potential to be adapted to varying tasks using a single platform and enable customizable robots to be developed faster and more...

  12. Numerical modelling of steel arc welding

    International Nuclear Information System (INIS)

    Hamide, M.

    2008-07-01

    Welding is a highly used assembly technique. Welding simulation software would give access to residual stresses and information about the weld's microstructure, in order to evaluate the mechanical resistance of a weld. It would also permit to evaluate the process feasibility when complex geometrical components are to be made, and to optimize the welding sequences in order to minimize defects. This work deals with the numerical modelling of arc welding process of steels. After describing the industrial context and the state of art, the models implemented in TransWeld (software developed at CEMEF) are presented. The set of macroscopic equations is followed by a discussion on their numerical implementation. Then, the theory of re-meshing and our adaptive anisotropic re-meshing strategy are explained. Two welding metal addition techniques are investigated and are compared in terms of the joint size and transient temperature and stresses. The accuracy of the finite element model is evaluated based on experimental results and the results of the analytical solution. Comparative analysis between experimental and numerical results allows the assessment of the ability of the numerical code to predict the thermomechanical and metallurgical response of the welded structure. The models limitations and the phenomena identified during this study are finally discussed and permit to define interesting orientations for future developments. (author)

  13. Robot engineering

    International Nuclear Information System (INIS)

    Jung, Seul

    2006-02-01

    This book deals with robot engineering, giving descriptions of robot's history, current tendency of robot field, work and characteristic of industrial robot, essential merit and vector, application of matrix, analysis of basic vector, expression of Denavit-Hartenberg, robot kinematics such as forward kinematics, inverse kinematics, cases of MATLAB program, and motion kinematics, robot kinetics like moment of inertia, centrifugal force and coriolis power, and Euler-Lagrangian equation course plan, SIMULINK position control of robots.

  14. Robot engineering

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seul

    2006-02-15

    This book deals with robot engineering, giving descriptions of robot's history, current tendency of robot field, work and characteristic of industrial robot, essential merit and vector, application of matrix, analysis of basic vector, expression of Denavit-Hartenberg, robot kinematics such as forward kinematics, inverse kinematics, cases of MATLAB program, and motion kinematics, robot kinetics like moment of inertia, centrifugal force and coriolis power, and Euler-Lagrangian equation course plan, SIMULINK position control of robots.

  15. The Combined Effects of Adaptive Control and Virtual Reality on Robot-Assisted Fine Hand Motion Rehabilitation in Chronic Stroke Patients: A Case Study.

    Science.gov (United States)

    Huang, Xianwei; Naghdy, Fazel; Naghdy, Golshah; Du, Haiping; Todd, Catherine

    2018-01-01

    Robot-assisted therapy is regarded as an effective and reliable method for the delivery of highly repetitive training that is needed to trigger neuroplasticity following a stroke. However, the lack of fully adaptive assist-as-needed control of the robotic devices and an inadequate immersive virtual environment that can promote active participation during training are obstacles hindering the achievement of better training results with fewer training sessions required. This study thus focuses on these research gaps by combining these 2 key components into a rehabilitation system, with special attention on the rehabilitation of fine hand motion skills. The effectiveness of the proposed system is tested by conducting clinical trials on a chronic stroke patient and verified through clinical evaluation methods by measuring the key kinematic features such as active range of motion (ROM), finger strength, and velocity. By comparing the pretraining and post-training results, the study demonstrates that the proposed method can further enhance the effectiveness of fine hand motion rehabilitation training by improving finger ROM, strength, and coordination. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  16. Eddy current testing system for bottom mounted instrumentation welds - 15206

    International Nuclear Information System (INIS)

    Kobayashi, N.; Ueno, S.; Suganuma, N.; Oodake, T.; Maehara, T.; Kasuya, T.; Ichikawa, H.

    2015-01-01

    We have demonstrated the scanning of eddy current testing (ECT) probe on the welds area including the nozzle, the J-welds and the buildup welds of the Bottom Mounted Instrumentation (BMI) mock-up using the developed ECT system and procedure. It is difficult to scan the probe on the BMI welds area because the area has a complex curved surface shape and narrow spaces. We made the space coordinates and the normal vectors on the scanning points as the scanning trajectory of probe on the welds area based on the measured results of welds surface shape on the mock-up. The multi-axis robot was used to scan the probe on the welds surface. Each motion axis position of the robot corresponding to each scanning point was calculated by the inverse kinematic algorithm. The BMI mock-up test was performed using the cross coil probe in the differential mode. The artificial stress corrosion cracking and the electrical discharge machining slits given on the mock-up surface were detected. The results show that the ECT can detect a defect of approximately 2.3 mm in length, 0.5 mm in depth and 0.2 mm in width for the BMI welds. From the output voltage of single coil, we estimated that the average and the maximum probe tilt angles on the mock-up surface under scanning were 2.6 degrees and 8.5 degrees, respectively

  17. WELDABILITY, WELDING METALLURGY, WELDING CHEMISTRY

    OpenAIRE

    Sarjito Jokosisworo

    2012-01-01

    Sambungan las merupakan bagian penting dari stuktur/bangunan yang dilas, dan kunci dari logam induk yang baik adalah kemampuan las (weld ability). Kemampuan las yang baik dan kemudahan dalam fabrikasi dari suatu logam merupakan pertimbangan dalam memilih suatu logam untuk konstruksi.

  18. IT Systems in Aid of Welding Processes Quality Management in the Automotive Industry

    Directory of Open Access Journals (Sweden)

    Restecka M.

    2016-12-01

    Full Text Available The most important issue for the producers nowadays is to meet the requirements of customers, satisfying their perceived but also the unperceived needs. In order to control the quality of welding processes correctly one must have knowledge of welding drawings, symbols, designs of welded joints, welding procedures, requirements set in codes and standards, also have knowledge of the techniques of inspection and testing connected with the automotive industry. The article shows ways to increase quality in the industry through the use of robotization and computerization. Presented examples and application of IT systems in aid of welding processes quality management in the automotive industry.

  19. Special Issue on Intelligent Robots

    Directory of Open Access Journals (Sweden)

    Genci Capi

    2013-08-01

    Full Text Available The research on intelligent robots will produce robots that are able to operate in everyday life environments, to adapt their program according to environment changes, and to cooperate with other team members and humans. Operating in human environments, robots need to process, in real time, a large amount of sensory data—such as vision, laser, microphone—in order to determine the best action. Intelligent algorithms have been successfully applied to link complex sensory data to robot action. This editorial briefly summarizes recent findings in the field of intelligent robots as described in the articles published in this special issue.

  20. Papers of the annual welding conference

    International Nuclear Information System (INIS)

    1981-01-01

    Interest will be mainly focussed on structural welding in the fields of vehicle, power generating plant, railway bridge, reactor, tank and pipeline construction as well as energy transmission, energy production and space travel. Also under discussion will be such topical subjects as health and safety and the use of welding robots in the automobile industry, both these topics bearing direct relation to one another, at it is the labour-saving and health aspects which take precedence in both areas and to which medical experts are making valuable contributions to an ever increasing extent. (orig./IHOE) [de

  1. WELDING PROCESS

    Science.gov (United States)

    Zambrow, J.; Hausner, H.

    1957-09-24

    A method of joining metal parts for the preparation of relatively long, thin fuel element cores of uranium or alloys thereof for nuclear reactors is described. The process includes the steps of cleaning the surfaces to be jointed, placing the sunfaces together, and providing between and in contact with them, a layer of a compound in finely divided form that is decomposable to metal by heat. The fuel element members are then heated at the contact zone and maintained under pressure during the heating to decompose the compound to metal and sinter the members and reduced metal together producing a weld. The preferred class of decomposable compounds are the metal hydrides such as uranium hydride, which release hydrogen thus providing a reducing atmosphere in the vicinity of the welding operation.

  2. Adaptation.

    Science.gov (United States)

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  3. Welding processes handbook

    CERN Document Server

    Weman, Klas

    2011-01-01

    Offers an introduction to the range of available welding technologies. This title includes chapters on individual techniques that cover principles, equipment, consumables and key quality issues. It includes material on such topics as the basics of electricity in welding, arc physics, and distortion, and the weldability of particular metals.$bThe first edition of Welding processes handbook established itself as a standard introduction and guide to the main welding technologies and their applications. This new edition has been substantially revised and extended to reflect the latest developments. After an initial introduction, the book first reviews gas welding before discussing the fundamentals of arc welding, including arc physics and power sources. It then discusses the range of arc welding techniques including TIG, plasma, MIG/MAG, MMA and submerged arc welding. Further chapters cover a range of other important welding technologies such as resistance and laser welding, as well as the use of welding techniqu...

  4. Report on results of 1998 regional consortium R and D project. 'Regional consortium energy R and D field' 'R and D of task-adaptive platoon transportation robot system, TRIPTERS'; 1998 nendo task tekigogatagun kosei hanso robot system TRIPTERS no kaihatsu kenkyu (dai 2 nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    For the purpose of realizing a task-adaptive platoon transportation robot system, R and D were conducted concerning functional modules, platoon transportation control technologies, etc.. In the R and D of a positioning module, measuring accuracy was examined in a stationary state in relation to the two- and three-dimensional instrumentation of a robot by using laser. In the R and D of a module for recognizing environmental state and avoiding obstacles, the steering of an autonomous running vehicle and a method of recognizing its position were examined using a stereo camera, with a steering theory constructed. In the R and D of a standardized robot, a large AGV (automated guided vehicle) and a running control program were prepared, with the validity verified for the hardware and the control method of the robot by the running test. In the R and D of a autonomous and distributed cooperative module and a small imaging module for workspace sensing, the movement of plural robots was simulated, with a simulator developed capable of visually confirming the movement. The experiment of the plural robots proved effectiveness of the clustering. (NEDO)

  5. Friction Stir Welding

    Science.gov (United States)

    Nunes, Arthur C., Jr.

    2008-01-01

    Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and promises to be an important welding process for any industries where welds of optimal quality are demanded. This article provides an introduction to the FSW process. The chief concern is the physical effect of the tool on the weld metal: how weld seam bonding takes place, what kind of weld structure is generated, potential problems, possible defects for example, and implications for process parameters and tool design. Weld properties are determined by structure, and the structure of friction stir welds is determined by the weld metal flow field in the vicinity of the weld tool. Metal flow in the vicinity of the weld tool is explained through a simple kinematic flow model that decomposes the flow field into three basic component flows: a uniform translation, a rotating solid cylinder, and a ring vortex encircling the tool. The flow components, superposed to construct the flow model, can be related to particular aspects of weld process parameters and tool design; they provide a bridge to an understanding of a complex-at-first-glance weld structure. Torques and forces are also discussed. Some simple mathematical models of structural aspects, torques, and forces are included.

  6. Adaptation

    International Development Research Centre (IDRC) Digital Library (Canada)

    building skills, knowledge or networks on adaptation, ... the African partners leading the AfricaAdapt network, together with the UK-based Institute of Development Studies; and ... UNCCD Secretariat, Regional Coordination Unit for Africa, Tunis, Tunisia .... 26 Rural–urban Cooperation on Water Management in the Context of.

  7. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    International Nuclear Information System (INIS)

    Lagov, P B; Drenin, A S; Zinoviev, M A

    2017-01-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding. (paper)

  8. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    Science.gov (United States)

    Lagov, P. B.; Drenin, A. S.; Zinoviev, M. A.

    2017-05-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding.

  9. Use of robotics in a Radwaste treatment plant

    International Nuclear Information System (INIS)

    Leeks, C.W.E.

    1991-01-01

    A 762 Unimate Puma, clean room standard Robot has been installed and commissioned in the Radwaste Treatment Plant at the Winfrith Technology Centre. The robot interacts with a variety of purpose designed tools and proprietary welding equipment. It performs 13 dedicated tasks in the final closure and health physics operations, before the 500 litre waste drum is despatched from the plant. (author)

  10. Multivariable Frequency Response Functions Estimation for Industrial Robots

    NARCIS (Netherlands)

    Hardeman, T.; Aarts, Ronald G.K.M.; Jonker, Jan B.

    2005-01-01

    The accuracy of industrial robots limits its applicability for high demanding processes, like robotised laser welding. We are working on a nonlinear exible model of the robot manipulator to predict these inaccuracies. This poster presents the experimental results on estimating the Multivariable

  11. Application of YAG laser processing in underwater welding and cutting

    Energy Technology Data Exchange (ETDEWEB)

    Ohwaki, Katsura; Morita, Ichiro; Kojima, Toshio; Sato, Shuichi [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    2002-09-01

    The high-power YAG laser is a new fabrication tool. The laser torch is easy to combine with complex with complex mechanics because of beam delivery through optical fiber. A direct underwater laser welding technology has been developed and applied to the preservation, maintenance and removal of nuclear power plants. For subdividing or removing operations for retirement of plants, the laser cutting properties were confirmed to allow a maximum cutting thickness of 80 mm. For repairing inner surface of stainless steel tanks, an underwater laser welding system using a remote-controlled robot was developed and the high quality of underwater laser welding was confirmed. (author)

  12. Studying Robots Outside the Lab

    DEFF Research Database (Denmark)

    Blond, Lasse

    and ethnographic studies will enhance understandings of the dynamics of HRI. Furthermore, the paper emphasizes how users and the context of use matters to integration of robots, as it is shown how roboticists are unable to control how their designs are implemented in practice and that the sociality of social...... robots is inscribed by its users in social practice. This paper can be seen as a contribution to studies of long-term HRI. It presents the challenges of robot adaptation in practice and discusses the limitations of the present conceptual understanding of human-robotic relations. The ethnographic data......As more and more robots enter our social world there is a strong need for further field studies of human-robotic interaction. Based on a two-year ethnographic study of the implementation of the South Korean socially assistive robot in Danish elderly care this paper argues that empirical...

  13. Introduction to Welding.

    Science.gov (United States)

    Fortney, Clarence; Gregory, Mike

    This curriculum guide provides six units of instruction on basic welding. Addressed in the individual units of instruction are the following topics: employment opportunities for welders, welding safety and first aid, welding tools and equipment, basic metals and metallurgy, basic math and measuring, and procedures for applying for a welding job.…

  14. Distortion Control during Welding

    NARCIS (Netherlands)

    Akbari Pazooki, A.M.

    2014-01-01

    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ

  15. Welding and cutting

    International Nuclear Information System (INIS)

    Drews, P.; Schulze Frielinghaus, W.

    1978-01-01

    This is a survey, with 198 literature references, of the papers published in the fields of welding and cutting within the last three years. The subjects dealt with are: weldability of the materials - Welding methods - Thermal cutting - Shaping and calculation of welded joints - Environmental protection in welding and cutting. (orig.) [de

  16. Globalization of Japanese steel industry. Part 2. Welding materials; Tekkogyo no kokusaika. 2. Yozai

    Energy Technology Data Exchange (ETDEWEB)

    Aida, I. [Kobe Steel, Ltd., Kobe (Japan)

    1995-01-01

    This paper mainly discusses the current status and problems of arc welding materials. The domestic production of welding materials has decreased. The recent trend of demand is characterized by the change of form make-up of welding materials. Various technologies for welding materials and their operation in Japan have developed with the progress of steel materials. The high quality and high-grade welding technologies, highly efficient production processes, laborsaving, and robotization have been promoted in various fields. In response to the rapid strong yen, quality and cost have to be further pursued, and amenity and cleanliness of welding have to be realized. The welding technologies have to be developed for large structures, such as ultra high-rise buildings, energy and chemical plants, ships, marine structures, etc. For the welding materials which are applied to robots and robot systems, obstruction factors for the operation have to be removed, which include the unsteady arc, re-arc badness, spattering, wear of chip, slag formation, etc. These measures promote the globalization of welding materials. 17 refs., 4 figs.

  17. High quality joining techniques: in-process assurance (IPA) welding system

    International Nuclear Information System (INIS)

    Kaihara, Shoichiro

    1996-01-01

    On July 1, 1995, the Product Liability Law was enforced, and in industrial world, further reliability has been demanded. Recently, accompanying the progress of electronics, the proportion taken by automatic welders and robots increased in welding. By memorizing proper welding conditions, the welding from initial to final passes can be done fully automatically. Also feedback mechanism was equipped to mechanized welders, and the in-process control has become to be feasible. The way of thinking on confirming in process welding quality in arc welding is explained. IPA welding system utilizes the multi-media collecting images and sound, samples the change of welding conditions and the state of arc on a same screen, and monitors the deviation from the range of proper welding conditions. At the time of abnormality, inspector or a computer carries out image diagnosis and welding control, and the system indicates the soundness of welded parts. The basic concept and the flow chart of this system are shown. The experiment of applying the system to arc welding is reported. The correlation of welding phenomena and welding conditions is examined. (K.I.)

  18. High quality joining techniques: in-process assurance (IPA) welding system

    Energy Technology Data Exchange (ETDEWEB)

    Kaihara, Shoichiro [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1996-08-01

    On July 1, 1995, the Product Liability Law was enforced, and in industrial world, further reliability has been demanded. Recently, accompanying the progress of electronics, the proportion taken by automatic welders and robots increased in welding. By memorizing proper welding conditions, the welding from initial to final passes can be done fully automatically. Also feedback mechanism was equipped to mechanized welders, and the in-process control has become to be feasible. The way of thinking on confirming in process welding quality in arc welding is explained. IPA welding system utilizes the multi-media collecting images and sound, samples the change of welding conditions and the state of arc on a same screen, and monitors the deviation from the range of proper welding conditions. At the time of abnormality, inspector or a computer carries out image diagnosis and welding control, and the system indicates the soundness of welded parts. The basic concept and the flow chart of this system are shown. The experiment of applying the system to arc welding is reported. The correlation of welding phenomena and welding conditions is examined. (K.I.)

  19. High productivity mould robotic milling in Al-5083

    Science.gov (United States)

    Urresti, Iker; Arrazola, Pedro Jose; Ørskov, Klaus Bonde; Pelegay, Jose Angel

    2018-05-01

    Industrial serial robots were usually limited to welding, handling or spray painting operations until very recent years. However, some industries have already realized about their important capabilities in terms of flexibility, working space, adaptability and cost. Hence, currently they are seriously being considered to carry out certain metal machining tasks. Therefore, robot based machining is presented as a cost-saving and flexible manufacturing alternative compared to conventional CNC machines especially for roughing or even pre-roughing of large parts. Nevertheless, there are still some drawbacks usually referred as low rigidity, accuracy and repeatability. Thus, the process productivity is usually sacrificed getting low Material Removal Rates (MRR), and consequently not being competitive. Nevertheless, in this paper different techniques to obtain increased productivity are presented, though an appropriate selection of cutting strategies and parameters that are essential for it. During this research some rough milling tests in Al-5083 are presented where High Feed Milling (HFM) is implemented as productive cutting strategy and the experimental modal analysis named Tap-testing is used for the suitable choice of cutting conditions. Competitive productivity rates are experienced while process stability is checked through the cutting forces measurements in order to prove the effectiveness of the experimental modal analysis for robotic machining.

  20. Task oriented evaluation system for maintenance robots

    International Nuclear Information System (INIS)

    Asame, Hajime; Endo, Isao; Kotosaka, Shin-ya; Takata, Shozo; Hiraoka, Hiroyuki; Kohda, Takehisa; Matsumoto, Akihiro; Yamagishi, Kiichiro.

    1994-01-01

    The adaptability evaluation of maintenance robots to autonomous plants has been discussed. In this paper, a new concept of autonomous plant with maintenance robots are introduced, and a framework of autonomous maintenance system is proposed. Then, task-oriented evaluation of robot arms is discussed for evaluating their adaptability to maintenance tasks, and a new criterion called operability is proposed for adaptability evaluation. The task-oriented evaluation system is implemented and applied to structural design of robot arms. Using genetic algorithm, an optimal structure adaptable to a pump disassembly task is obtained. (author)

  1. Indigenous robotics technology in nuclear industries (Paper No. 039)

    Energy Technology Data Exchange (ETDEWEB)

    Challappa, S; Guha, S

    1987-01-01

    Robots are essential for material handling, stripping, fitting, welding and other operations in a hazardous environment as exits in nuclear industries. Adoptivity of the equipment to environment to carry out remote activity, accuracy of the performance and quality are the primordial considerations for selection of such types of robots. The essential features of a typical robot are described in this paper. As a first step towards development of such a robot, a six-axis multipurpose robot developed in Central Workshops, Bhabha Atomic Research Centre, is also described in this paper. (author). 2 figs.

  2. Indigenous robotics technology in nuclear industries (Paper No. 039)

    International Nuclear Information System (INIS)

    Challappa, S.; Guha, S.

    1987-02-01

    Robots are essential for material handling, stripping, fitting, welding and other operations in a hazardous environment as exits in nuclear industries. Adoptivity of the equipment to environment to carry out remote activity, accuracy of the performance and quality are the primordial considerations for selection of such types of robots. The essential features of a typical robot are described in this paper. As a first step towards development of such a robot, a six-axis multipurpose robot developed in Central Workshops, Bhabha Atomic Research Centre, is also described in this paper. (author). 2 figs

  3. Reservoir-based Online Adaptive Forward Models with Neural Control for Complex Locomotion in a Hexapod Robot

    DEFF Research Database (Denmark)

    Manoonpong, Poramate; Dasgupta, Sakyasingha; Goldschmidt, Dennis

    2014-01-01

    Walking animals show fascinating locomotor abilities and complex behaviors. Biological study has revealed that such complex behaviors is a result of a combination of biomechanics and neural mechanisms. While biomechanics allows for flexibility and a variety of movements, neural mechanisms generate...... locomotion, make predictions, and provide adaptation. Inspired by this finding, we present here an artificial bio-inspired walking system which combines biomechanics (in terms of its body and leg structures) and neural mechanisms. The neural mechanisms consist of 1) central pattern generator-based control...... for generating basic rhythmic patterns and coordinated movements, 2) reservoir-based adaptive forward models with efference copies for sensory prediction as well as state estimation, and 3) searching and elevation control for adapting the movement of an individual leg to deal with different environmental...

  4. Advanced Welding Applications

    Science.gov (United States)

    Ding, Robert J.

    2010-01-01

    Some of the applications of advanced welding techniques are shown in this poster presentation. Included are brief explanations of the use on the Ares I and Ares V launch vehicle and on the Space Shuttle Launch vehicle. Also included are microstructural views from four advanced welding techniques: Variable Polarity Plasma Arc (VPPA) weld (fusion), self-reacting friction stir welding (SR-FSW), conventional FSW, and Tube Socket Weld (TSW) on aluminum.

  5. A MIT-Based Nonlinear Adaptive Set-Membership Filter for the Ellipsoidal Estimation of Mobile Robots' States

    Directory of Open Access Journals (Sweden)

    Dalei Song

    2012-10-01

    Full Text Available The adaptive extended set-membership filter (AESMF for nonlinear ellipsoidal estimation suffers a mismatch between real process noise and its set boundaries, which may result in unstable estimation. In this paper, a MIT method-based adaptive set-membership filter, for the optimization of the set boundaries of process noise, is developed and applied to the nonlinear joint estimation of both time-varying states and parameters. As a result of using the proposed MIT-AESMF, the estimation effectiveness and boundary accuracy of traditional AESMF are substantially improved. Simulation results have shown the efficiency and robustness of the proposed method.

  6. In Pipe Robot with Hybrid Locomotion System

    Directory of Open Access Journals (Sweden)

    Cristian Miclauş

    2015-06-01

    Full Text Available The first part of the paper covers aspects concerning in pipe robots and their components, such as hybrid locomotion systems and the adapting mechanisms used. The second part describes the inspection robot that was developed, which combines tracked and wheeled locomotion (hybrid locomotion. The end of the paper presents the advantages and disadvantages of the proposed robot.

  7. Evolutionary robotics

    Indian Academy of Sciences (India)

    In evolutionary robotics, a suitable robot control system is developed automatically through evolution due to the interactions between the robot and its environment. It is a complicated task, as the robot and the environment constitute a highly dynamical system. Several methods have been tried by various investigators to ...

  8. Robot Aesthetics

    DEFF Research Database (Denmark)

    Jochum, Elizabeth Ann; Putnam, Lance Jonathan

    This paper considers art-based research practice in robotics through a discussion of our course and relevant research projects in autonomous art. The undergraduate course integrates basic concepts of computer science, robotic art, live performance and aesthetic theory. Through practice...... in robotics research (such as aesthetics, culture and perception), we believe robot aesthetics is an important area for research in contemporary aesthetics....

  9. Filigree Robotics

    DEFF Research Database (Denmark)

    Tamke, Martin; Evers, Henrik Leander; Clausen Nørgaard, Esben

    2016-01-01

    Filigree Robotics experiments with the combination of traditional ceramic craft with robotic fabrication in order to generate a new narrative of fine three-dimensional ceramic ornament for architecture.......Filigree Robotics experiments with the combination of traditional ceramic craft with robotic fabrication in order to generate a new narrative of fine three-dimensional ceramic ornament for architecture....

  10. Adapt

    Science.gov (United States)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  11. A mobile robot with parallel kinematics to meet the requirements for assembling and machining the ITER vacuum vessel

    International Nuclear Information System (INIS)

    Pessi, Pekka; Wu, Huapeng; Handroos, Heikki; Jones, Lawrence

    2007-01-01

    The present paper introduces a mobile parallel robot developed for International Thermonuclear Experimental Reactor (ITER). The task of the robot is to carry out welding and machining processes inside the ITER vacuum vessel. The kinematic design of the robot has been optimized for the ITER access. The kinematic analysis is given in the paper. A virtual prototype of the parallel robot is built. A dynamic behavior of the whole robot is studied by the multi-body system simulation (MBS)

  12. A mobile robot with parallel kinematics to meet the requirements for assembling and machining the ITER vacuum vessel

    Energy Technology Data Exchange (ETDEWEB)

    Pessi, Pekka [Lappeenranta University of Technology, Lappeenranta (Finland)], E-mail: pessi@lut.fi; Wu, Huapeng; Handroos, Heikki [Lappeenranta University of Technology, Lappeenranta (Finland); Jones, Lawrence [EFDA Close Support Unit, Boltzmannstrasse 2, Garching D-85748 (Germany)

    2007-10-15

    The present paper introduces a mobile parallel robot developed for International Thermonuclear Experimental Reactor (ITER). The task of the robot is to carry out welding and machining processes inside the ITER vacuum vessel. The kinematic design of the robot has been optimized for the ITER access. The kinematic analysis is given in the paper. A virtual prototype of the parallel robot is built. A dynamic behavior of the whole robot is studied by the multi-body system simulation (MBS)

  13. Mergeable nervous systems for robots.

    Science.gov (United States)

    Mathews, Nithin; Christensen, Anders Lyhne; O'Grady, Rehan; Mondada, Francesco; Dorigo, Marco

    2017-09-12

    Robots have the potential to display a higher degree of lifetime morphological adaptation than natural organisms. By adopting a modular approach, robots with different capabilities, shapes, and sizes could, in theory, construct and reconfigure themselves as required. However, current modular robots have only been able to display a limited range of hardwired behaviors because they rely solely on distributed control. Here, we present robots whose bodies and control systems can merge to form entirely new robots that retain full sensorimotor control. Our control paradigm enables robots to exhibit properties that go beyond those of any existing machine or of any biological organism: the robots we present can merge to form larger bodies with a single centralized controller, split into separate bodies with independent controllers, and self-heal by removing or replacing malfunctioning body parts. This work takes us closer to robots that can autonomously change their size, form and function.Robots that can self-assemble into different morphologies are desired to perform tasks that require different physical capabilities. Mathews et al. design robots whose bodies and control systems can merge and split to form new robots that retain full sensorimotor control and act as a single entity.

  14. Traveling Robots and Their Cultural Baggage

    DEFF Research Database (Denmark)

    Blond, Lasse

    When social robots are imported from Asia to Europe they bring along with them a cultural luggage consisting of foreign sociotechnical imaginary. The effort to adopt the robot Silbot to Nordic social services exposed unfamiliar and cultural-dependent views of care, cognition, health and human...... nature. Studying Silbot in “the wild” highlighted these issues as well as the human-robot interaction and the adaptation of the robot to real life praxis. The importance of comprehending robots as parts of sociotechnical ensembles is emphasized as well as the observance of how robots are shaped...... by the cultural context in the recipient countries....

  15. Selected Welding Techniques, Part 2

    National Research Council Canada - National Science Library

    1964-01-01

    Partial contents: CONVENTIONAL WELD JOINTS VERSUS BUTT JOINTS IN 1-INCH ALUMINUM PLATE, SPECIAL WELD JOINT PREPARATION, UPSET METAL EDGES FOR INCREASED WELD JOINT STRENGTH, OUT-OF-POSITION WELDING OF HEAVY GAGE...

  16. Design, implementation and testing of a fuzzy control scheme for laser welding

    NARCIS (Netherlands)

    Jauregui Becker, Juan Manuel; Aalderink, B.J.; Aalderink, Benno; Aarts, Ronald G.K.M.; Olde Benneker, Jeroen; Meijer, J.

    2008-01-01

    A fuzzy logic controller (FLC) scheme has been developed for laser welding. Process light emissions are measured and combined to determine the current status of the welding process. If the process is not in a desired welding state, the FLC will adapt the laser power. The FLC has been demonstrated

  17. Robot welding process control development task

    Science.gov (United States)

    Romine, Peter L.

    1992-01-01

    The completion of, and improvements made to, the software developed during 1990 for program maintenance on the PC and HEURIKON and transfer to the CYRO, and integration of the Rocketdyne vision software with the CYRO is documented. The new programs were used successfully by NASA, Rocketdyne, and UAH technicians and engineers to create, modify, upload, download, and control CYRO NC programs.

  18. Toward cognitive robotics

    Science.gov (United States)

    Laird, John E.

    2009-05-01

    Our long-term goal is to develop autonomous robotic systems that have the cognitive abilities of humans, including communication, coordination, adapting to novel situations, and learning through experience. Our approach rests on the recent integration of the Soar cognitive architecture with both virtual and physical robotic systems. Soar has been used to develop a wide variety of knowledge-rich agents for complex virtual environments, including distributed training environments and interactive computer games. For development and testing in robotic virtual environments, Soar interfaces to a variety of robotic simulators and a simple mobile robot. We have recently made significant extensions to Soar that add new memories and new non-symbolic reasoning to Soar's original symbolic processing, which should significantly improve Soar abilities for control of robots. These extensions include episodic memory, semantic memory, reinforcement learning, and mental imagery. Episodic memory and semantic memory support the learning and recalling of prior events and situations as well as facts about the world. Reinforcement learning provides the ability of the system to tune its procedural knowledge - knowledge about how to do things. Mental imagery supports the use of diagrammatic and visual representations that are critical to support spatial reasoning. We speculate on the future of unmanned systems and the need for cognitive robotics to support dynamic instruction and taskability.

  19. Robotics in space-age manufacturing

    Science.gov (United States)

    Jones, Chip

    1991-01-01

    Robotics technologies are developed to improve manufacturing of space hardware. The following applications of robotics are covered: (1) welding for the space shuttle and space station Freedom programs; (2) manipulation of high-pressure water for shuttle solid rocket booster refurbishment; (3) automating the application of insulation materials; (4) precision application of sealants; and (5) automation of inspection procedures. Commercial robots are used for these development programs, but they are teamed with advanced sensors, process controls, and computer simulation to form highly productive manufacturing systems. Many of the technologies are also being actively pursued in private sector manufacturing operations.

  20. Evolutionary Robotics: What, Why, and Where to

    Directory of Open Access Journals (Sweden)

    Stephane eDoncieux

    2015-03-01

    Full Text Available Evolutionary robotics applies the selection, variation, and heredity principles of natural evolution to the design of robots with embodied intelligence. It can be considered as a subfield of robotics that aims to create more robust and adaptive robots. A pivotal feature of the evolutionary approach is that it considers the whole robot at once, and enables the exploitation of robot features in a holistic manner. Evolutionary robotics can also be seen as an innovative approach to the study of evolution based on a new kind of experimentalism. The use of robots as a substrate can help address questions that are difficult, if not impossible, to investigate through computer simulations or biological studies. In this paper we consider the main achievements of evolutionary robotics, focusing particularly on its contributions to both engineering and biology. We briefly elaborate on methodological issues, review some of the most interesting findings, and discuss important open issues and promising avenues for future work.

  1. Biological Soft Robotics.

    Science.gov (United States)

    Feinberg, Adam W

    2015-01-01

    In nature, nanometer-scale molecular motors are used to generate force within cells for diverse processes from transcription and transport to muscle contraction. This adaptability and scalability across wide temporal, spatial, and force regimes have spurred the development of biological soft robotic systems that seek to mimic and extend these capabilities. This review describes how molecular motors are hierarchically organized into larger-scale structures in order to provide a basic understanding of how these systems work in nature and the complexity and functionality we hope to replicate in biological soft robotics. These span the subcellular scale to macroscale, and this article focuses on the integration of biological components with synthetic materials, coupled with bioinspired robotic design. Key examples include nanoscale molecular motor-powered actuators, microscale bacteria-controlled devices, and macroscale muscle-powered robots that grasp, walk, and swim. Finally, the current challenges and future opportunities in the field are addressed.

  2. Automatic welding of fuel elements

    International Nuclear Information System (INIS)

    Briola, J.

    1958-01-01

    The welding process depends on the type of fuel element, the can material and the number of cartridges to be welded: - inert-gas welding (used for G2 and the 1. set of EL3), - inert atmosphere arc welding (used for welding uranium and zirconium), - electronic welding (used for the 2. set of EL3 and the tank of Proserpine). (author) [fr

  3. Detecting flaws in welds

    International Nuclear Information System (INIS)

    Woodacre, A.; Lawton, H.

    1979-01-01

    An apparatus and a method for detecting flaws in welds in a workpiece, the portion of the workpiece containing the weld is maintained at a constant temperature and the weld is scanned by an infra red detector. The weld is then scanned again with the workpiece in contact with a cooling probe to produce a steeper temperature gradient across the weld. Comparison of the signals produced by each scan reveals the existence of defects in the welds. The signals may be displayed on an oscilloscope and the display may be observed by a TV camera and recorded on videotape. (UK)

  4. Fusion welding process

    Science.gov (United States)

    Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

    1983-01-01

    A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

  5. Weld controller for automated nuclear service welding

    International Nuclear Information System (INIS)

    Barfield, K.L.; Strubhar, P.M.; Green, D.I.

    1995-01-01

    B and W Nuclear Technologies (BWNT) uses many different types of weld heads for automated welding in the commercial nuclear service industry. Some weld heads are purchased as standard items, while others are custom designed and fabricated by BWNT requiring synchronized multiaxis motion control. BWNT recently completed a development program to build a common weld controller that interfaces to all types of weld heads used by BWNT. Their goal was to construct a system that had the flexibility to add different modules to increase the capability of the controller as different application needs become necessary. The benefits from having a common controller are listed. This presentation explains the weld controller system and the types of applications to which it has been applied

  6. Robotic Manufacturing of 18-ft (5.5m) Diameter Cryogenic Fuel Tank Dome Assemblies for the NASA Ares I Rocket

    Science.gov (United States)

    Jones, Ronald E.; Carter, Robert W.

    2012-01-01

    The Ares I rocket was the first launch vehicle scheduled for manufacture under the National Aeronautic and Space Administration's Constellation program. A series of full-scale Ares I development articles were constructed on the Robotic Weld Tool at the NASA George C. Marshall Space Flight Center in Huntsville, Alabama. The Robotic Weld Tool is a 100 ton, 7- axis, robotic manufacturing system capable of machining and friction stir welding large-scale space hardware. This paper will focus on the friction stir welding of 18-ft (5.5m) diameter cryogenic fuel tank components; specifically, the liquid hydrogen forward dome and two common bulkhead manufacturing development articles.

  7. Detailed characterization of welding fumes in personal exposure samples

    International Nuclear Information System (INIS)

    Quémerais, B; Mino, James; Amin, M R; Golshahi, H; Izadi, H

    2015-01-01

    The objective of the project was to develop a method allowing for detailed characterization of welding particles including particle number concentration, size distribution, surface chemistry and chemical composition of individual particles, as well as metal concentration of various welding fumes in personal exposure samples using regular sampling equipment. A sample strategy was developed to evaluate the variation of the collection methods on mass concentration. Samples were collected with various samplers and filters at two different locations using our collection system. The first location was using a robotic welding system while the second was manual welding. Collected samples were analysed for mass concentration using gravimetryand metal concentration using ICP/OES. More advanced analysis was performed on selected filters using X-Ray Photoelectron Spectroscopy to determine surface composition of the particles, and X-Ray Diffraction to determine chemical composition of the fumes. Results showed that the robotic system had a lot of variation in space when the collection system was located close to the weld. Collection efficiency was found to be quite variable depending upon the type of filter. As well, metal concentrations in blank filters were dependent upon the type of filter with MCE presenting with the highest blank values. Results obtained with the XRD and XPS systems showed that it was possible to analyse a small of powdered welding fume sample but results on filters were not conclusive. (paper)

  8. Generation IV SFR Nuclear Reactors: Under Sodium Robotics for ASTRID

    International Nuclear Information System (INIS)

    Jouan-de-Kervenoael, T.; Rey, F.; Baque, F.

    2013-06-01

    For non-removable components of the future ASTRID prototype, repair operations will be performed in a gas environment. If the faulty area is located under the sodium free level, the gas-tight system will have to contain the inspection and repair tools and to protect them from the surrounding liquid sodium. Concerning repair tools, the unique laser tool has been selected for future SFRs: the repair scenario for in-sodium structures will first involve removing the sodium (after bulk draining), then machining and finally welding. Concerning conventional tools (brush or gas blower for sodium removal, milling machine for machining and TIG for welding for which its feasibility was demonstrated in the 1990's) are still considered as a back-up solution. The maintenance of future ASTRID nuclear reactor prototype (inspection, repair) will be performed during shut down periods with some robotic carriers which have to be introduced within the main vessel, in primary 200 deg. C sodium coolant with argon gas cover. Inspection campaigns will be 20 days long. These robots (or carriers) will allow bringing inspection and repairing tools up to concerned components and structures. The needed degrees of freedom associated to these operations will be assumed either directly by the carrier itself or by specifics lower end carrier device for accurate local positioning. Several carriers will be designed, well adapted to specific needs: type of maintenance operation and location of inspection and repair sites. Feedback experience was gained during Superphenix SFR operation with the MIR robot which allowed to successfully make the Non Destructive Examination of main vessel welding joints, the carrier being outside bulk sodium. Operating conditions for the ASTRID robots will be harder from those of the MIR robot: temperature ranging from 180 deg. C to 200 deg. C, radiation dose ranging from 105 to 106 Gy, but mainly direct immersion within liquid sodium coolant. At the design phase of

  9. Nondestructive testing: welding industry

    International Nuclear Information System (INIS)

    Raj, Baldev; Subramanian, C.V.

    1992-01-01

    This chapter highlights various conventional and advanced nondestructive testing (NDT) techniques that have been used for weld evaluation. Welding Codes and Standards of International and National organisations that have been followed in India for various weld evaluation purposes are also included. The chapter also emphasises the importance of NDT by way of a few case studies that have been carried out on important critical welded components. (author). 12 refs., 17 figs., 1 appendix

  10. Robotic environments

    NARCIS (Netherlands)

    Bier, H.H.

    2011-01-01

    Technological and conceptual advances in fields such as artificial intelligence, robotics, and material science have enabled robotic architectural environments to be implemented and tested in the last decade in virtual and physical prototypes. These prototypes are incorporating sensing-actuating

  11. Instructional Guidelines. Welding.

    Science.gov (United States)

    Fordyce, H. L.; Doshier, Dale

    Using the standards of the American Welding Society and the American Society of Mechanical Engineers, this welding instructional guidelines manual presents a course of study in accordance with the current practices in industry. Intended for use in welding programs now practiced within the Federal Prison System, the phases of the program are…

  12. Welding Course Curriculum.

    Science.gov (United States)

    Genits, Joseph C.

    This guide is intended for use in helping students gain a fundamental background on the major aspects of the welding trade. The course emphasis is on mastery of the manipulative skills necessary to develop successful welding techniques and on acquisition of an understanding of the specialized tools and equipment used in welding. The first part…

  13. Underwater welding of steel

    International Nuclear Information System (INIS)

    Ibarra, S.; Olson, D.L.

    1992-01-01

    A fundamental basis to understand the behavior of wet underwater welding of steel is introduced. Both the pyrometallurgical and physical metallurgy concepts are discussed. Modifications of welding consumables and practice are suggested. This chapter promotes further contributions of meatllurgical research to improve and promote wet underwater welding. (orig.)

  14. Welding Over Paint Primer

    National Research Council Canada - National Science Library

    Johnson, Kevin S; Liu, Stephen; Olson, David L

    1998-01-01

    .... According to the hydrogen-oxygen and }hydrogen-fluorine equilibrium considerations, an increase in the partial pressure of oxygen or fluorine could decrease the partial pressure of hydrogen within the welding arc. Consequently, a welding consumable that contains chemical ingredients of high oxygen and fluorine potential would be capable of minimizing hydrogen pick-up in the weld pool.

  15. Recent progress in the field of automated welding applied to maintenance activities

    International Nuclear Information System (INIS)

    Cullafroz, M.

    2004-01-01

    Automated and robot welding has 5 advantages compared to manual welding: -) under some conditions the automated circular welding does not require requalification testing as manual welding does, -) welding heads in robots have a reduced size compared to manual gears so they can enter and treat complex piping, -) by using an adequate viewing system the operator can be more than 10 meters away from the welding site which means that the radiation doses he receives is cut by a factor 1.5 to 2, -) whatever the configuration is, the deposition rate in automated welding stays high, the quality standard is steady and the risk of repairing is low, -) a gain in productivity if adequate equipment is used. In general, automated welding requires a TIG welding process and is applied in maintenance activities to: -) the main primary system and other circuits in stainless austenitic steels, -) the main secondary system and other circuits in low-percentage carbon steels, and -) the closure of spent fuel canisters. An application to the repairing of BWR's pipes is shown. (A.C.)

  16. Marinization concept for the TRICEPT TR600 robot

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, A.; Aust, E.; Niemann, H.R.; Santos, J.F. dos [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Materialforschung; Hammerin, R.; Neumann, K.E. [Neos Robotics AB, Taeby (Sweden); Gibson, D. [National Hyperbaric Centre, Aberdeen (United Kingdom)

    1998-11-01

    The need for automated welding repair systems of marine structures, ship hulls and nuclear installations had lead to an increasing demand for subsea robots. Considering the application of friction welding to perform underwater repairs, a TRICEPT TR600 robot has been identified as the most suitable system to withstand the high reaction forces characteristic of this process. This study reviews initially the research and development work carried out at GKSS to modify and test a Siemens-MANUTEC robot. After a description of the TRICEPT TR600 robot a marinization concept is presented and discussed in detail. Problems of galvanic corrosion in seawater are addressed in a separate chapter. The deflection of the robot in subsea water currents is estimated with a worst-case calculation. (orig.) [Deutsch] Der Wunsch, Roboter auch unter Wasser einsetzen zu koennen, waechst mit steigendem Interesse nach automatisierten Schweissverfahren fuer Reparaturen an marinen Bauwerken, Schiffsruempfen und in Kernenergieanlagen. Fuer den Einsatz von Reibschweissverfahren fuer diese Reparaturen wurde der TRICEPT TR600-Roboter ausgewaehlt, da dieser auch den charakteristisch hohen Prozesskraeften widerstehen kann. Die notwendigen Modifikationen und Pruefungen werden beispielhaft anhand des bei der GKSS modifizierten Siemens-MANUTEC-Roboters vorgestellt. Nach einer Beschreibung des TRICEPT-Roboters werden die notwendigen Umbaumassnahmen detailliert dargestellt und diskutiert. Auf die Problematik der galvanischen Korrosion in Seewasser wird in einem gesonderten Kapitel naeher eingegangen. Zusaetzlich wird eine moegliche Ablenkung des Roboters durch Wasserstroemung ueberschlaegig berechnet. (orig.)

  17. Healthcare Robotics

    OpenAIRE

    Riek, Laurel D.

    2017-01-01

    Robots have the potential to be a game changer in healthcare: improving health and well-being, filling care gaps, supporting care givers, and aiding health care workers. However, before robots are able to be widely deployed, it is crucial that both the research and industrial communities work together to establish a strong evidence-base for healthcare robotics, and surmount likely adoption barriers. This article presents a broad contextualization of robots in healthcare by identifying key sta...

  18. Industrial Robots.

    Science.gov (United States)

    Reed, Dean; Harden, Thomas K.

    Robots are mechanical devices that can be programmed to perform some task of manipulation or locomotion under automatic control. This paper discusses: (1) early developments of the robotics industry in the United States; (2) the present structure of the industry; (3) noneconomic factors related to the use of robots; (4) labor considerations…

  19. Self-Organizing Robots

    CERN Document Server

    Murata, Satoshi

    2012-01-01

    It is man’s ongoing hope that a machine could somehow adapt to its environment by reorganizing itself. This is what the notion of self-organizing robots is based on. The theme of this book is to examine the feasibility of creating such robots within the limitations of current mechanical engineering. The topics comprise the following aspects of such a pursuit: the philosophy of design of self-organizing mechanical systems; self-organization in biological systems; the history of self-organizing mechanical systems; a case study of a self-assembling/self-repairing system as an autonomous distributed system; a self-organizing robot that can create its own shape and robotic motion; implementation and instrumentation of self-organizing robots; and the future of self-organizing robots. All topics are illustrated with many up-to-date examples, including those from the authors’ own work. The book does not require advanced knowledge of mathematics to be understood, and will be of great benefit to students in the rob...

  20. Advanced cutting, welding and inspection methods for vacuum vessel assembly and maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Jones, L. E-mail: jonesl@ipp.mgg.de; Alfile, J.-P.; Aubert, Ph.; Punshon, C.; Daenner, W.; Kujanpaeae, V.; Maisonnier, D.; Serre, M.; Schreck, G.; Wykes, M

    2000-11-01

    ITER requires a 316 l stainless steel, double-skinned vacuum vessel (VV), each shell being 60 mm thick. EFDA (European Fusion Development Agreement) is investigating methods to be used for performing welding and NDT during VV assembly and also cutting and re-welding for remote sector replacement, including the development of an Intersector Welding Robot (IWR) [Jones et al. This conference]. To reduce the welding time, distortions and residual stresses of conventional welding, previous work concentrated on CO{sub 2} laser welding and cutting processes [Jones et al. Proc. Symp. Fusion Technol., Marseilles, 1998]. NdYAG laser now provides the focus for welding of the rearside root and for completing the weld for overhead positions with multipass filling. Electron beam (E-beam) welding with local vacuum offers a single-pass for most of the weld depth except for overhead positions. Plasma cutting has shown the capability to contain the backside dross and preliminary work with NdYAG laser cutting has shown good results. Automated ultrasonic inspection of assembly welds will be improved by the use of a phased array probe system that can focus the beam for accurate flaw location and sizing. This paper describes the recent results of process investigations in this R and D programme, involving five European sites and forming part of the overall VV/blanket research effort [W. Daenner et al. This conference].

  1. Present and future of laser welding machine; Laser yosetsuki no genjo to tenbo

    Energy Technology Data Exchange (ETDEWEB)

    Taniu, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1998-04-01

    This paper describes recent trends of laser welding machine. For CO2 laser welding machine, seam weld of large diameter weld pipes using a 25 kW-class machine, and plate weld of steel plate using a 45 kW-class machine are reported. For YAG laser welding machine, high-output 5.5 kW-class machines are commercialized. Machines with slab structure of plate-like YAG chrystal have been developed which show high-oscillation efficiency and can be applied to cutting. Machines have been developed in which YAG laser output with slab structure is transmitted through GI fiber. High-speed welding of aluminum alloys can be realized by improving the converging performance. Efficiency of YAG laser can be enhanced through the time-divided utilization by switching the beam transmission path using fiber change-over switch. In the automobile industry, CO2 laser is mainly used, and a system combining CO laser with articulate robot is realized. TIG and MIG welding is often used for welding of aluminum for railway vehicles. It is required to reduce the welding strain. In the iron and steel industry, the productivity has been improved by the laser welding. YAG laser is put into practice for nuclear reactors. 5 refs., 8 figs., 1 tab.

  2. A flexible, computer-integrated robotic transfer system

    International Nuclear Information System (INIS)

    Lewis, W.I. III; Taylor, R.M.

    1987-01-01

    This paper reviews a robotic system used to transport materials across a radiation control zone and into a row of shielded cells. The robot used is a five-axis GCA 600 industrial robot mounted on a 50-ft ESAB welding track. Custom software incorporates the track as the sixth axis of motion. An IBM-PC integrates robot control, force sensing, and the operator interface. Multiple end-effectors and a quick exchange mechanism are used to handle a variety of materials and tasks. Automatic error detection and recovery is a key aspect of this system

  3. Orbital welding technique

    International Nuclear Information System (INIS)

    Hoeschen, W.

    2003-01-01

    The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.) [de

  4. Robot Mechanisms

    CERN Document Server

    Lenarcic, Jadran; Stanišić, Michael M

    2013-01-01

    This book provides a comprehensive introduction to the area of robot mechanisms, primarily considering industrial manipulators and humanoid arms. The book is intended for both teaching and self-study. Emphasis is given to the fundamentals of kinematic analysis and the design of robot mechanisms. The coverage of topics is untypical. The focus is on robot kinematics. The book creates a balance between theoretical and practical aspects in the development and application of robot mechanisms, and includes the latest achievements and trends in robot science and technology.

  5. Homogeneous weldings of copper

    International Nuclear Information System (INIS)

    Campurri, C.; Lopez, M.; Fernandez, R.; Osorio, V.

    1995-01-01

    This research explored the metallurgical and mechanical properties of arc welding of copper related with influence of Argon, Helium and mixtures of them. Copper plates of 6 mm thickness were welded with different mixtures of the mentioned gases. The radiography of welded specimens with 100% He and 100% Ar does not show show any porosity. On the other hand, the copper plates welded different gas mixtures presented uniform porosity in the welded zone. The metallographies show recrystallized grain in the heat affected zone, while the welding zone showed a dendritic structure. The results of the tensile strength vary between a maximum of 227 MPa for 100% He and a minimum of 174 MOa for the mixture of 60% He and 40% Ar. For the elongation after fracture the best values, about 36%, were obtained for pure gases. As a main conclusion, we can say that arc welding of copper is possible without loosing the mechanical and metallurgical properties of base metal. 6 refs

  6. Robot Futures

    DEFF Research Database (Denmark)

    Christoffersen, Anja; Grindsted Nielsen, Sally; Jochum, Elizabeth Ann

    Robots are increasingly used in health care settings, e.g., as homecare assistants and personal companions. One challenge for personal robots in the home is acceptance. We describe an innovative approach to influencing the acceptance of care robots using theatrical performance. Live performance...... is a useful testbed for developing and evaluating what makes robots expressive; it is also a useful platform for designing robot behaviors and dialogue that result in believable characters. Therefore theatre is a valuable testbed for studying human-robot interaction (HRI). We investigate how audiences...... perceive social robots interacting with humans in a future care scenario through a scripted performance. We discuss our methods and initial findings, and outline future work....

  7. Robotics education

    International Nuclear Information System (INIS)

    Benton, O.

    1984-01-01

    Robotics education courses are rapidly spreading throughout the nation's colleges and universities. Engineering schools are offering robotics courses as part of their mechanical or manufacturing engineering degree program. Two year colleges are developing an Associate Degree in robotics. In addition to regular courses, colleges are offering seminars in robotics and related fields. These seminars draw excellent participation at costs running up to $200 per day for each participant. The last one drew 275 people from Texas to Virginia. Seminars are also offered by trade associations, private consulting firms, and robot vendors. IBM, for example, has the Robotic Assembly Institute in Boca Raton and charges about $1,000 per week for course. This is basically for owners of IBM robots. Education (and training) can be as short as one day or as long as two years. Here is the educational pattern that is developing now

  8. Emotion based human-robot interaction

    Directory of Open Access Journals (Sweden)

    Berns Karsten

    2018-01-01

    Full Text Available Human-machine interaction is a major challenge in the development of complex humanoid robots. In addition to verbal communication the use of non-verbal cues such as hand, arm and body gestures or mimics can improve the understanding of the intention of the robot. On the other hand, by perceiving such mechanisms of a human in a typical interaction scenario the humanoid robot can adapt its interaction skills in a better way. In this work, the perception system of two social robots, ROMAN and ROBIN of the RRLAB of the TU Kaiserslautern, is presented in the range of human-robot interaction.

  9. Intracranial stereotactic radiosurgery with an adapted linear accelerator vs. robotic radiosurgery. Comparison of dosimetric treatment plan quality

    Energy Technology Data Exchange (ETDEWEB)

    Treuer, Harald; Hoevels, Moritz; Luyken, Klaus; Visser-Vandewalle, Veerle; Wirths, Jochen; Ruge, Maximilian [University Hospital Cologne, Department of Stereotaxy and Functional Neurosurgery, Cologne (Germany); Kocher, Martin [University Hospital Cologne, Department of Radiotherapy, Cologne (Germany)

    2014-11-22

    Stereotactic radiosurgery with an adapted linear accelerator (linac-SRS) is an established therapy option for brain metastases, benign brain tumors, and arteriovenous malformations. We intended to investigate whether the dosimetric quality of treatment plans achieved with a CyberKnife (CK) is at least equivalent to that for linac-SRS with circular or micromultileaf collimators (microMLC). A random sample of 16 patients with 23 target volumes, previously treated with linac-SRS, was replanned with CK. Planning constraints were identical dose prescription and clinical applicability. In all cases uniform optimization scripts and inverse planning objectives were used. Plans were compared with respect to coverage, minimal dose within target volume, conformity index, and volume of brain tissue irradiated with ≥ 10 Gy. Generating the CK plan was unproblematic with simple optimization scripts in all cases. With the CK plans, coverage, minimal target volume dosage, and conformity index were significantly better, while no significant improvement could be shown regarding the 10 Gy volume. Multiobjective comparison for the irradiated target volumes was superior in the CK plan in 20 out of 23 cases and equivalent in 3 out of 23 cases. Multiobjective comparison for the treated patients was superior in the CK plan in all 16 cases. The results clearly demonstrate the superiority of the irradiation plan for CK compared to classical linac-SRS with circular collimators and microMLC. In particular, the average minimal target volume dose per patient, increased by 1.9 Gy, and at the same time a 14 % better conformation index seems to be an improvement with clinical relevance. (orig.) [German] Stereotaktische Radiochirurgie mit einem adaptierten Linearbeschleuniger (Linac-SRS) ist eine erfolgreiche und etablierte Therapieoption fuer Hirnmetastasen, benigne Hirntumoren und arteriovenoese Malformationen. Ziel war es, zu untersuchen, ob die mit einem CyberKnife (CK) erreichbare

  10. Welding of iridium heat source capsule components

    International Nuclear Information System (INIS)

    Mustaleski, T.M.; Yearwood, J.C.; Burgan, C.E.; Green, L.A.

    1991-01-01

    Interplanetary spacecraft have long used radioisotope thermoelectric generators (RTG) to produce power for instrumentation. These RTG produce electrical energy from the heat generated through the radioactive decay of plutonium-238. The plutonium is present as a ceramic pellet of plutonium oxide. The pellet is encapsulated in a containment shell of iridium. Iridium is the material of choice for these capsules because of its compatibility with the plutonium dioxide. The high-energy beam welding (electron beam and laser) processes used in the fabrication of the capsules has not been published. These welding procedures were originally developed at the Mound Laboratories and have been adapted for use at the Oak Ridge Y-12 Plant. The work involves joining of thin material in small sizes to exacting tolerances. There are four different electron beam welds on each capsule, with one procedure being used in three locations. There is also a laser weld used to seal the edges of a sintered frit assembly. An additional electron beam weld is also performed to seal each of the iridium blanks in a stainless steel waster sheet prior to forming. In the transfer of these welding procedures from one facility to another, a number of modifications were necessary. These modifications are discussed in detail, as well as the inherent problems in making welds in material which is only 0.005 in. thick. In summary, the paper discusses the welding of thin components of iridium using the high energy beam processes. While the peculiarities of iridium are pertinent to the discussion, much of the information is of general interest to the users of these processes. This is especially true of applications involving thin materials and high-precision assemblies

  11. Adaptive Control Of Remote Manipulator

    Science.gov (United States)

    Seraji, Homayoun

    1989-01-01

    Robotic control system causes remote manipulator to follow closely reference trajectory in Cartesian reference frame in work space, without resort to computationally intensive mathematical model of robot dynamics and without knowledge of robot and load parameters. System, derived from linear multivariable theory, uses relatively simple feedforward and feedback controllers with model-reference adaptive control.

  12. Risk-adapted robotic stereotactic body radiation therapy for inoperable early-stage non-small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Temming, Susanne; Kocher, Martin; Baus, Wolfgang W.; Semrau, Robert; Baues, Christian; Marnitz, S. [University of Cologne, Department of Radiation Oncology, Center for Integrated Oncology, Cologne (Germany); Stoelben, Erich [Hospital of Cologne, Lung Clinic Merheim, Cologne (Germany); Hagmeyer, Lars [University of Cologne, Bethanien Hospital, Institute of Pneumology, Solingen (Germany); Chang, De-Hua [University of Cologne, Department of Diagnostic and Interventional Radiology, Center for Integrated Oncology, Cologne (Germany); Frank, Konrad [Heart Centre of the University of Cologne, Department III of Internal Medicine, Cologne (Germany); Hekmat, Khosro [University of Cologne, Department of Cardiothoracic Surgery, Center for Integrated Oncology, Cologne (Germany); Wolf, Juergen [University Hospital of Cologne, First Department of Internal Medicine, Center for Integrated Oncology, Cologne (Germany)

    2018-02-15

    To evaluate efficacy and toxicity of stereotactic body radiation therapy (SBRT) with CyberKnife {sup registered} (Accuray, Sunnyvale, CA, USA) in a selected cohort of primary, medically inoperable early-stage non-small cell lung cancer (NSCLC) patients. From 2012 to 2016, 106 patients (median age 74 years, range 50-94 years) with primary NSCLC were treated with SBRT using CyberKnife {sup registered}. Histologic confirmation was available in 87 patients (82%). For mediastinal staging, 92 patients (87%) underwent {sup 18}F-fluorodeoxyglucose positron-emission tomography (18-FDG-PET) and/or endobronchial ultrasound (EBUS)-guided lymph node biopsy or mediastinoscopy. Tumor stage (UICC8, 2017) was IA/B (T1a-c, 1-3 cm) in 86 patients (81%) and IIA (T2a/b, 3-5 cm) in 20 patients (19%). Depending on tumor localization, three different fractionation schedules were used: 3 fractions of 17Gy, 5 fractions of 11Gy, or 8 fractions of 7.5 Gy. Tracking was based on fiducial implants in 13 patients (12%) and on image guidance without markers in 88%. Median follow-up was 15 months (range 0.5-46 months). Acute side effects were mild (fatigue grade 1-2 in 20% and dyspnea grade 1-2 in 17%). Late effects were observed in 4 patients (4%): 3 patients developed pneumonitis requiring therapy (grade 2) and 1 patient suffered a rib fracture (grade 3). In total, 9/106 patients (8%) experienced a local recurrence, actuarial local control rates were 88% (95% confidence interval, CI, 80-96%) at 2 years and 77% (95%CI 56-98%) at 3 years. The median disease-free survival time was 27 months (95%CI 23-31 months). Overall survival was 77% (95%CI 65-85%) at 2 years and 56% (95%CI 39-73%) at 3 years. CyberKnife {sup registered} lung SBRT which allows for real-time tumor tracking and risk-adapted fractionation achieves satisfactory local control and low toxicity rates in inoperable early-stage primary lung cancer patients. (orig.) [German] Untersuchung von Wirkung und Toxizitaet einer stereotaktischen

  13. Nd-YAG laser welding of bare and galvanised steels

    International Nuclear Information System (INIS)

    Kennedy, S.C.; Norris, I.M.

    1989-01-01

    Until recently, one of the problems that has held back the introduction of lasers into car body fabrication has been the difficulty of integrating the lasers with robots. Nd-YAG laser beams can be transmitted through fibre optics which, as well as being considerably easier to manipulate than a mirror system, can be mounted on more lightweight accurate robots. Although previously only available at low powers, recent developments in Nd-YAG laser technology mean that lasers of up to 1kW average power will soon be available, coupled to a fibre optic beam delivery system. The increasing usage of zinc coated steels in vehicle bodies has led to welding problems using conventional resistance welding as well as CO 2 laser welding. The use of Nd-YAG lasers may be able to overcome these problems. This paper outlines work carried out at The Welding Institute on a prototype Lumonics 800W pulsed Nd-YAG laser to investigate its welding characteristics on bare and zinc coated car body steels

  14. Robotic buildings(s)

    NARCIS (Netherlands)

    Bier, H.H.

    2014-01-01

    Technological and conceptual advances in fields such as artificial intelligence, robotics, and material science have enabled robotic building to be in the last decade prototypically implemented. In this context, robotic building implies both physically built robotic environments and robotically

  15. Modular robotic applications in nuclear power plant maintenance

    International Nuclear Information System (INIS)

    Glass, S.W.; Ranson, C.C.; Reinholtz, C.F.; Calkins, J.M.

    1996-01-01

    General-purpose factory automation robots have experienced limited use in nuclear maintenance and hazardous-environment work spaces due to demanding requirements on size, weight, mobility and adaptability. Robotic systems in nuclear power plants are frequently custom designed to meet specific space and performance requirements. Examples of these custom configurations include Framatome Technologies COBRA trademark Steam Generator Manipulator and URSULA trademark Reactor Vessel Inspection Manipulator. The use of custom robots in nuclear plants has been limited because of the lead time and expense associated with custom design. Developments in modular robotics and advanced robot control software coupled with more powerful low-cost computers, however, are helping to reduce the cost and schedule for deploying custom robots. A modular robotic system allows custom robot configurations to be implemented using standard (modular) joints and adaptable controllers. This paper discusses Framatome Technologies (FTI) current and planned developments in the area of modular robot system design

  16. Ultrasonic Real-Time Quality Monitoring Of Aluminum Spot Weld Process

    Science.gov (United States)

    Perez Regalado, Waldo Josue

    The real-time ultrasonic spot weld monitoring system, introduced by our research group, has been designed for the unsupervised quality characterization of the spot welding process. It comprises the ultrasonic transducer (probe) built into one of the welding electrodes and an electronics hardware unit which gathers information from the transducer, performs real-time weld quality characterization and communicates with the robot programmable logic controller (PLC). The system has been fully developed for the inspection of spot welds manufactured in steel alloys, and has been mainly applied in the automotive industry. In recent years, a variety of materials have been introduced to the automotive industry. These include high strength steels, magnesium alloys, and aluminum alloys. Aluminum alloys have been of particular interest due to their high strength-to-weight ratio. Resistance spot welding requirements for aluminum vary greatly from those of steel. Additionally, the oxide film formed on the aluminum surface increases the heat generation between the copper electrodes and the aluminum plates leading to accelerated electrode deterioration. Preliminary studies showed that the real-time quality inspection system was not able to monitor spot welds manufactured with aluminum. The extensive experimental research, finite element modelling of the aluminum welding process and finite difference modeling of the acoustic wave propagation through the aluminum spot welds presented in this dissertation, revealed that the thermodynamics and hence the acoustic wave propagation through an aluminum and a steel spot weld differ significantly. For this reason, the hardware requirements and the algorithms developed to determine the welds quality from the ultrasonic data used on steel, no longer apply on aluminum spot welds. After updating the system and designing the required algorithms, parameters such as liquid nugget penetration and nugget diameter were available in the ultrasonic data

  17. Welding skate with computerized controls

    Science.gov (United States)

    Wall, W. A., Jr.

    1968-01-01

    New welding skate concept for automatic TIG welding of contoured or double-contoured parts combines lightweight welding apparatus with electrical circuitry which computes the desired torch angle and positions a torch and cold-wire guide angle manipulator.

  18. Development of automatic pre-tracking system for fillet weld based on laser trigonometry

    Science.gov (United States)

    Shen, Xiaoqin; Yu, Fusheng

    2005-01-01

    In this paper, an automatic fillet weld pre-tracking system for welding the work piece of lorry back boards with several bend in haul automobile is developed basing on laser trigonometry. The optical measuring head based on laser-PSD trigonometry is used as position sensor. It is placed in front of the traveling direction of welding wire to get the distances from welding wire to the two side boards of the welding lines, upper board and bottom board of the fillet weld respectively. A chip of AT89S52 is used as the micro controller in this system. The AC servomotors, ball-screws and straight guide rails constitute the sliding table to take welding wire move. The laser-PSD sensors pass through the vertical board, upper board and bottom board of the fillet weld when welding wire moves and then get the distance. The laser-PSD sensors output the analog signals. After A/D conversion, the digital signal is input into AT89S52 and calculated. Then the information of the position and lateral deviation of the welding wire when welding a certain position are gotten to control welding wires. So the weld pre-tracking for welding the work piece with long distance and large bend in haul automobile is realized. The position information is input into EEPROM to be saved for short time after handled by AT89S52. The information is as the welding position information as well as the speed adjusting data of the welding wire when it welds the several bend of the work piece. The practice indicates that this system has high pre-tracking precision, good anti-disturb ability, excellent reliability, easy operating ability and good adaptability to the field of production.

  19. Ultrasonic Stir Welding

    Science.gov (United States)

    Nabors, Sammy

    2015-01-01

    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  20. Automatization of welding

    International Nuclear Information System (INIS)

    Iwabuchi, Masashi; Tomita, Jinji; Nishihara, Katsunori.

    1978-01-01

    Automatization of welding is one of the effective measures for securing high degree of quality of nuclear power equipment, as well as for correspondence to the environment at the site of plant. As the latest ones of the automatic welders practically used for welding of nuclear power apparatuses in factories of Toshiba and IHI, those for pipes and lining tanks are described here. The pipe welder performs the battering welding on the inside of pipe end as the so-called IGSCC countermeasure and the succeeding butt welding through the same controller. The lining tank welder is able to perform simultaneous welding of two parallel weld lines on a large thin plate lining tank. Both types of the welders are demonstrating excellent performance at the shops as well as at the plant site. (author)

  1. Soft Robotics.

    Science.gov (United States)

    Whitesides, George M

    2018-04-09

    This description of "soft robotics" is not intended to be a conventional review, in the sense of a comprehensive technical summary of a developing field. Rather, its objective is to describe soft robotics as a new field-one that offers opportunities to chemists and materials scientists who like to make "things" and to work with macroscopic objects that move and exert force. It will give one (personal) view of what soft actuators and robots are, and how this class of soft devices fits into the more highly developed field of conventional "hard" robotics. It will also suggest how and why soft robotics is more than simply a minor technical "tweak" on hard robotics and propose a unique role for chemistry, and materials science, in this field. Soft robotics is, at its core, intellectually and technologically different from hard robotics, both because it has different objectives and uses and because it relies on the properties of materials to assume many of the roles played by sensors, actuators, and controllers in hard robotics. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. A study on autonomous maintenance robot, 7

    International Nuclear Information System (INIS)

    Fukuda, Toshio; Hosokai, Hidemi; Shimasaka, Naoki; Kaneshige, Masanori; Iwasaki, Shinnosuke.

    1990-01-01

    This paper deals with the new mechanism of a new maintenance robot, Mark IV, following the previous reports on pipeline inspection and maintenance robots of Mark I, II, and III. The Mark IV has a mechanism capable of inspecting surfaces of storage tanks as well as pipeline outer surfaces, which is another capability of the maintenance robots, different from the previous ones. The main features of Mark IV are as follows, (i) The robot has a multijoint structure, so that it has better adaptability to the curvartures of pipelines and storage tanks. (ii) The joint of the robot has SMA actuators to make the robot lighter in weight. Some actuator shape characteristics are also examined for the robot structure and control. (iii) The robot has suckers at both ends so that the robot can climb up along the wall from the ground. (iv) A robot with the inch worm mechanisms has many functional motions, such that it can pass over flanges and T-joints, and transfer to adjacent pipelines with a wider range of pipe diameters. (v) A control method is given for the mobile motion control. Thus, the functional level of the maintenance robot has been greatly improved by the introduction of the Mark IV robot. (author)

  3. Learning for intelligent mobile robots

    Science.gov (United States)

    Hall, Ernest L.; Liao, Xiaoqun; Alhaj Ali, Souma M.

    2003-10-01

    Unlike intelligent industrial robots which often work in a structured factory setting, intelligent mobile robots must often operate in an unstructured environment cluttered with obstacles and with many possible action paths. However, such machines have many potential applications in medicine, defense, industry and even the home that make their study important. Sensors such as vision are needed. However, in many applications some form of learning is also required. The purpose of this paper is to present a discussion of recent technical advances in learning for intelligent mobile robots. During the past 20 years, the use of intelligent industrial robots that are equipped not only with motion control systems but also with sensors such as cameras, laser scanners, or tactile sensors that permit adaptation to a changing environment has increased dramatically. However, relatively little has been done concerning learning. Adaptive and robust control permits one to achieve point to point and controlled path operation in a changing environment. This problem can be solved with a learning control. In the unstructured environment, the terrain and consequently the load on the robot"s motors are constantly changing. Learning the parameters of a proportional, integral and derivative controller (PID) and artificial neural network provides an adaptive and robust control. Learning may also be used for path following. Simulations that include learning may be conducted to see if a robot can learn its way through a cluttered array of obstacles. If a situation is performed repetitively, then learning can also be used in the actual application. To reach an even higher degree of autonomous operation, a new level of learning is required. Recently learning theories such as the adaptive critic have been proposed. In this type of learning a critic provides a grade to the controller of an action module such as a robot. The creative control process is used that is "beyond the adaptive critic." A

  4. Collision-free motion coordination of heterogeneous robots

    International Nuclear Information System (INIS)

    Ko, Nak Yong; Seo, Dong Jin; Simmons, Reid G.

    2008-01-01

    This paper proposes a method to coordinate the motion of multiple heterogeneous robots on a network. The proposed method uses prioritization and avoidance. Priority is assigned to each robot; a robot with lower priority avoids the robots of higher priority. To avoid collision with other robots, elastic force and potential field force are used. Also, the method can be applied separately to the motion planning of a part of a robot from that of the other parts of the robot. This is useful for application to the robots of the type mobile manipulator or highly redundant robots. The method is tested by simulation, and it results in smooth and adaptive coordination in an environment with multiple heterogeneous robots

  5. Collision-free motion coordination of heterogeneous robots

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Nak Yong [Chosun University, Gwangju (Korea, Republic of); Seo, Dong Jin [RedOne Technologies, Gwangju (Korea, Republic of); Simmons, Reid G. [Carnegie Mellon University, Pennsylvania (United States)

    2008-11-15

    This paper proposes a method to coordinate the motion of multiple heterogeneous robots on a network. The proposed method uses prioritization and avoidance. Priority is assigned to each robot; a robot with lower priority avoids the robots of higher priority. To avoid collision with other robots, elastic force and potential field force are used. Also, the method can be applied separately to the motion planning of a part of a robot from that of the other parts of the robot. This is useful for application to the robots of the type mobile manipulator or highly redundant robots. The method is tested by simulation, and it results in smooth and adaptive coordination in an environment with multiple heterogeneous robots

  6. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  7. Electric arc welding gun

    Science.gov (United States)

    Luttrell, Edward; Turner, Paul W.

    1978-01-01

    This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.

  8. Electron beam welding

    International Nuclear Information System (INIS)

    Schwartz, M.M.

    1974-01-01

    Electron-beam equipment is considered along with fixed and mobile electron-beam guns, questions of weld environment, medium and nonvacuum welding, weld-joint designs, tooling, the economics of electron-beam job shops, aspects of safety, quality assurance, and repair. The application of the process in the case of individual materials is discussed, giving attention to aluminum, beryllium, copper, niobium, magnesium, molybdenum, tantalum, titanium, metal alloys, superalloys, and various types of steel. Mechanical-property test results are examined along with the areas of application of electron-beam welding

  9. Use of servo controlled weld head for end closure welding

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  10. Fuzzy Behaviors for Control of Mobile Robots

    Directory of Open Access Journals (Sweden)

    Saleh Zein-Sabatto

    2003-02-01

    Full Text Available In this research work, an RWI B-14 robot has been used as the development platform to embody some basic behaviors that can be combined to build more complex robotics behaviors. Emergency, avoid-obstacle, left wall- following, right wall-following, and move-to-point behaviors have been designed and embodied as basic robot behaviors. The basic behaviors developed in this research are designed based on fuzzy control technique and are integrated and coordinated to from complex robotics system. More behaviors can be added into the system as needed. A robot task can be defined by the user and executed by the intelligent robot control system. Testing results showed that fuzzy behaviors made the robot move intelligently and adapt to changes in its environment.

  11. Designing the robot inclusive space challenge

    Directory of Open Access Journals (Sweden)

    Rajesh Elara Mohan

    2015-11-01

    Full Text Available A novel robotic challenge, namely the robot inclusive spaces (RIS challenge, is proposed in this paper, which is a cross disciplinary and design focused initiative. It aims to foster the roboticists, architects, and designers towards realizing robot friendly social spaces. Contrary to conventional robotics competitions focusing on designing robots and its component technologies, robot inclusive spaces challenge adopts an interdisciplinary “design for robots” strategy to overcome the traditional research problem in real world deployments of social robots. In order to realize the RIS, various architectural elements must be adapted including: design principles for inclusive spaces, lighting schemes, furniture choices and arrangement, wall and floor surfaces, pathways among others. This paper introduces the format and design principles of RIS challenge, presents a first run of the challenge, and gives the corresponding analysis.

  12. Formal-Language-Theoretic Control & Coordination of Mobile Robots

    National Research Council Canada - National Science Library

    Ray, Asok

    2007-01-01

    .... The research has formulated and experimentally validated robust adaptive algorithms and software codes for decision and control of mobile robotic platforms, as applied to real-time computation...

  13. Robotics 101

    Science.gov (United States)

    Sultan, Alan

    2011-01-01

    Robots are used in all kinds of industrial settings. They are used to rivet bolts to cars, to move items from one conveyor belt to another, to gather information from other planets, and even to perform some very delicate types of surgery. Anyone who has watched a robot perform its tasks cannot help but be impressed by how it works. This article…

  14. Vitruvian Robot

    DEFF Research Database (Denmark)

    Hasse, Cathrine

    2017-01-01

    future. A real version of Ava would not last long in a human world because she is basically a solipsist, who does not really care about humans. She cannot co-create the line humans walk along. The robots created as ‘perfect women’ (sex robots) today are very far from the ideal image of Ava...

  15. Beijing international welding fair report. Kokusaika ni ugokidashita chugoku yosetsukai

    Energy Technology Data Exchange (ETDEWEB)

    1991-07-01

    This paper reports the affairs at the Beijing International Scientific Conference for Welding and the International Welding Fair held in May 1991, including visitors{prime} comments on their impression. The Scientific Conference was held for three days in eleven sessions, where 135 theses were presented, most of which were related to high-tech areas including robotization, automation, laser welding and cutting, and ceramic bonding. The total attendance numbered 231 members, including 30 from Germany, 20 from Japan, 17 from Soviet, 7 from Korea, and one each from Finland and Switzerland, plus 150 from China. It was the third meeting for the Scientific Conference, which had the number of attendance jumped from the previous one showing the increased interest by the international welding industry toward China. Exhibits from overseas countries were few, a possible effect from the Tiananmen incident, only three from Japan. Welding machines exhibited by China were those made in or licensed by Japan. Strong impression was felt on the spread in use of CO{sub 2} semi-automatic welding machines. 3 figs.

  16. Accuracy analysis of hybrid parallel robot for the assembling of ITER

    International Nuclear Information System (INIS)

    Wang Yongbo; Pessi, Pekka; Wu Huapeng; Handroos, Heikki

    2009-01-01

    This paper presents a novel mobile parallel robot, which is able to carry welding and machining processes from inside the international thermonuclear experimental reactor (ITER) vacuum vessel (VV). The kinematics design of the robot has been optimized for ITER access. To improve the accuracy of the parallel robot, the errors caused by the stiffness and manufacture process have to be compensated or limited to a minimum value. In this paper kinematics errors and stiffness modeling are given. The simulation results are presented.

  17. Accuracy analysis of hybrid parallel robot for the assembling of ITER

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yongbo [Institute of Mechatronics and Virtual Engineering, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta (Finland); The State Key Laboratory of Mechanical Transmission, Chongqing University (China); Pessi, Pekka [Institute of Mechatronics and Virtual Engineering, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta (Finland); Wu Huapeng [Institute of Mechatronics and Virtual Engineering, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta (Finland)], E-mail: huapeng@lut.fi; Handroos, Heikki [Institute of Mechatronics and Virtual Engineering, Lappeenranta University of Technology, Skinnarilankatu 34, 53850 Lappeenranta (Finland)

    2009-06-15

    This paper presents a novel mobile parallel robot, which is able to carry welding and machining processes from inside the international thermonuclear experimental reactor (ITER) vacuum vessel (VV). The kinematics design of the robot has been optimized for ITER access. To improve the accuracy of the parallel robot, the errors caused by the stiffness and manufacture process have to be compensated or limited to a minimum value. In this paper kinematics errors and stiffness modeling are given. The simulation results are presented.

  18. Robot Teachers

    DEFF Research Database (Denmark)

    Nørgård, Rikke Toft; Ess, Charles Melvin; Bhroin, Niamh Ni

    The world's first robot teacher, Saya, was introduced to a classroom in Japan in 2009. Saya, had the appearance of a young female teacher. She could express six basic emotions, take the register and shout orders like 'be quiet' (The Guardian, 2009). Since 2009, humanoid robot technologies have...... developed. It is now suggested that robot teachers may become regular features in educational settings, and may even 'take over' from human teachers in ten to fifteen years (cf. Amundsen, 2017 online; Gohd, 2017 online). Designed to look and act like a particular kind of human; robot teachers mediate human...... existence and roles, while also aiming to support education through sophisticated, automated, human-like interaction. Our paper explores the design and existential implications of ARTIE, a robot teacher at Oxford Brookes University (2017, online). Drawing on an initial empirical exploration we propose...

  19. Social Robots

    DEFF Research Database (Denmark)

    Social robotics is a cutting edge research area gathering researchers and stakeholders from various disciplines and organizations. The transformational potential that these machines, in the form of, for example, caregiving, entertainment or partner robots, pose to our societies and to us as indiv......Social robotics is a cutting edge research area gathering researchers and stakeholders from various disciplines and organizations. The transformational potential that these machines, in the form of, for example, caregiving, entertainment or partner robots, pose to our societies and to us...... as individuals seems to be limited by our technical limitations and phantasy alone. This collection contributes to the field of social robotics by exploring its boundaries from a philosophically informed standpoint. It constructively outlines central potentials and challenges and thereby also provides a stable...

  20. Robotic seeding

    DEFF Research Database (Denmark)

    Pedersen, Søren Marcus; Fountas, Spyros; Sørensen, Claus Aage Grøn

    2017-01-01

    Agricultural robotics has received attention for approximately 20 years, but today there are only a few examples of the application of robots in agricultural practice. The lack of uptake may be (at least partly) because in many cases there is either no compelling economic benefit......, or there is a benefit but it is not recognized. The aim of this chapter is to quantify the economic benefits from the application of agricultural robots under a specific condition where such a benefit is assumed to exist, namely the case of early seeding and re-seeding in sugar beet. With some predefined assumptions...... with regard to speed, capacity and seed mapping, we found that among these two technical systems both early seeding with a small robot and re-seeding using a robot for a smaller part of the field appear to be financially viable solutions in sugar beet production....

  1. Measuring weld heat to evaluate weld integrity

    Energy Technology Data Exchange (ETDEWEB)

    Schauder, V., E-mail: schauder@hks-prozesstechnik.de [HKS-Prozesstechnik GmbH, Halle (Germany)

    2015-11-15

    Eddy current and ultrasonic testing are suitable for tube and pipe mills and have been used for weld seam flaw detection for decades, but a new process, thermography, is an alternative. By measuring the heat signature of the weld seam as it cools, it provides information about weld integrity at and below the surface. The thermal processes used to join metals, such as plasma, induction, laser, and gas tungsten arc welding (GTAW), have improved since they were developed, and they get better with each passing year. However, no industrial process is perfect, so companies that conduct research in flaw detection likewise continue to develop and improve the technologies used to verify weld integrity: ultrasonic testing (UT), eddy current testing (ET), hydrostatic, X-ray, magnetic particle, and liquid penetrant are among the most common. Two of these are used for verifying the integrity of the continuous welds such as those used on pipe and tube mills: UT and ET. Each uses a transmitter to send waves of ultrasonic energy or electrical current through the material and a receiver (probe) to detect disturbances in the flow. The two processes often are combined to capitalize on the strengths of each. While ET is good at detecting flaws at or near the surface, UT penetrates the material, detecting subsurface flaws. One drawback is that sound waves and electrical current waves have a specific direction of travel, or an alignment. A linear defect that runs parallel to the direction of travel of the ultrasonic sound wave or a flaw that is parallel to the coil winding direction of the ET probe can go undetected. A second drawback is that they don't detect cold welds. An alternative process, thermography, works in a different fashion: It monitors the heat of the material as the weld cools. Although it measures the heat at the surface, the heat signature provides clues about cooling activity deep in the material, resulting in a thorough assessment of the weld's integrity It

  2. Micro intelligence robot

    International Nuclear Information System (INIS)

    Jeon, Yon Ho

    1991-07-01

    This book gives descriptions of micro robot about conception of robots and micro robot, match rules of conference of micro robots, search methods of mazes, and future and prospect of robots. It also explains making and design of 8 beat robot like making technique, software, sensor board circuit, and stepping motor catalog, speedy 3, Mr. Black and Mr. White, making and design of 16 beat robot, such as micro robot artist, Jerry 2 and magic art of shortening distances algorithm of robot simulation.

  3. An Intelligent Robot Programing

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seong Yong

    2012-01-15

    This book introduces an intelligent robot programing with background of the begging, introduction of VPL, and SPL, building of environment for robot platform, starting of robot programing, design of simulation environment, robot autonomy drive control programing, simulation graphic. Such as SPL graphic programing graphical image and graphical shapes, and graphical method application, application of procedure for robot control, robot multiprogramming, robot bumper sensor programing, robot LRF sencor programing and robot color sensor programing.

  4. An Intelligent Robot Programing

    International Nuclear Information System (INIS)

    Hong, Seong Yong

    2012-01-01

    This book introduces an intelligent robot programing with background of the begging, introduction of VPL, and SPL, building of environment for robot platform, starting of robot programing, design of simulation environment, robot autonomy drive control programing, simulation graphic. Such as SPL graphic programing graphical image and graphical shapes, and graphical method application, application of procedure for robot control, robot multiprogramming, robot bumper sensor programing, robot LRF sencor programing and robot color sensor programing.

  5. TIG welding method and TIG welding device

    International Nuclear Information System (INIS)

    Yoneda, Eishi

    1998-01-01

    The present invention provides a method of TIG welding for members having different heat capacities including a cladding tube and an end plug of a fuel rod to be used, for example, in a reactor, and a device therefor. Namely, in the TIG welding method, the flow rate of a sealed gas to the side of a member having smaller heat capacity is made greater than that on the side of the member having greater heat capacity bordered on the top end of a welding electrode. Since the sealed gas is jetted being localized relative to the welding electrode, arc is restricted in a region of the member having smaller heat capacity and is increased at a region having a larger heat capacity. As a result, the arc is localized, so that the heat input amount to the region having a large heat capacity is increased, and then a plurality of members at the abutting portion are melted uniformly thereby capable of obtaining a uniform molten pool. A bead is formed at the abutting portion thereby capable of obtaining a welded portion with less unevenness and having large strength. (I.S.)

  6. Explosion metal welding

    International Nuclear Information System (INIS)

    Popoff, A.A.

    1976-01-01

    Process parameters pertaining to welding similar and dissimilar metals using explosives are reviewed. The discussion centers on the interrelationship of physical parameters which play a part in achieving desirable metallurgical results. Present activities in explosion metal welding at LASL are presented and shown how they related to the interests of the ERDA community

  7. Electron beam welding

    International Nuclear Information System (INIS)

    Gabbay, M.

    1972-01-01

    The bead characteristics and the possible mechanisms of the electron beam penetration are presented. The different welding techniques are exposed and the main parts of an electron beam welding equipment are described. Some applications to nuclear, spatial and other industries are cited [fr

  8. The Relative Merits of Transparency: Investigating Situations that Support the Use of Robotics in Developing Student Learning Adaptability across Virtual and Physical Computing Platforms

    Science.gov (United States)

    Okita, Sandra Y.

    2014-01-01

    This study examined whether developing earlier forms of knowledge in specific learning environments prepares students better for future learning when they are placed in an unfamiliar learning environment. Forty-one students in the fifth and sixth grades learned to program robot movements using abstract concepts of speed, distance and direction.…

  9. Exploration and Learning for Cognitive Robots

    NARCIS (Netherlands)

    Rudinac, M.

    2013-01-01

    Before a future with household robots is really feasible, those robots need to be easily adaptable to novel environments and users, be able to apply previously acquired knowledge, and able to learn from perceiving and interacting with the world and users around them. This thesis proposes a cognitive

  10. Innovative electron-beam welding of high-melting metals

    International Nuclear Information System (INIS)

    Behr, W.; Reisgen, U.

    2007-01-01

    Since its establishment as nuclear research plant Juelich in the year 1956, the research centre Juelich (FZJ) is concerned with the material processing of special metals. Among those are, above all, the high-melting refractory metals niobium, molybdenum and tungsten. Electron beam welding has always been considered to be an innovative special welding method; in the FZJ, electron beam welding has, moreover, always been adapted to the increasing demands made by research partners and involved manufacturing and design sectors. From the manual equipment technology right up to highly modern multi-beam technique, the technically feasible for fundamental research has, this way, always been realised. (Abstract Copyright [2007], Wiley Periodicals, Inc.) [de

  11. Welding problems in nuclear power engineering

    International Nuclear Information System (INIS)

    Zubchenko, A.S.

    1986-01-01

    The problems of welding industry in nuclear power plant engineering, mainly related to the improvement of molten bath protection, are considered. Development of new materials for welding electrodes, for cladding and welding fluxes, is pointed out. Production of the following equipment is brought to a commercial level: welding heads and welding machines for branch pipe welding, anticorrosion cladding, zonal thermal treatment, electron beam welding facilities for the welding and maintenance of turbineblades, equipment for nondestructive testing of welded joints

  12. Method for welding beryllium

    Science.gov (United States)

    Dixon, R.D.; Smith, F.M.; O`Leary, R.F.

    1997-04-01

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. 9 figs.

  13. Method for welding beryllium

    International Nuclear Information System (INIS)

    Dixon, R.D.; Smith, F.M.; O'Leary, R.F.

    1997-01-01

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. 9 figs

  14. Transition welds in welding of two-ply steels

    International Nuclear Information System (INIS)

    Fartushnyj, V.G.; Evsyukov, Yu.G.

    1977-01-01

    Studied were physico-mechanical properties of welds made by various welding wires of chromium-nickel and nickel-chromium steels in submerged arc welding of double-layer steels with main layer of the VSt.3sp. carbon steel. It is shown that service-reliable structures welded of two-layer steels are obtained by providing the content from 11 to 20 % Ni in the automatically welded transition layer

  15. Novel low-cost vision-sensing technology with controllable of exposal time for welding

    Science.gov (United States)

    Zhang, Wenzeng; Wang, Bin; Chen, Nian; Cao, Yipeng

    2005-02-01

    In the process of robot Welding, position of welding seam and welding pool shape is detected by CCD camera for quality control and seam tracking in real-time. It is difficult to always get a clear welding image in some welding methods, such as TIG welding. A novel idea that the exposal time of CCD camera is automatically controlled by arc voltage or arc luminance is proposed to get clear welding image. A set of special device and circuits are added to a common industrial CCD camera in order to flexibly control the CCD to start or close exposal by control of the internal clearing signal of the accumulated charge. Two special vision sensors according to the idea are developed. Their exposal grabbing can be triggered respectively by the arc voltage and the variety of the arc luminance. Two prototypes have been designed and manufactured. Experiments show that they can stably grab clear welding images at appointed moment, which is a basic for the feedback control of automatic welding.

  16. Biological Immune System Applications on Mobile Robot for Disabled People

    Directory of Open Access Journals (Sweden)

    Songmin Jia

    2014-01-01

    Full Text Available To improve the service quality of service robots for the disabled, immune system is applied on robot for its advantages such as diversity, dynamic, parallel management, self-organization, and self-adaptation. According to the immune system theory, local environment condition sensed by robot is considered an antigen while robot is regarded as B-cell and possible node as antibody, respectively. Antibody-antigen affinity is employed to choose the optimal possible node to ensure the service robot can pass through the optimal path. The paper details the immune system applications on service robot and gives experimental results.

  17. Grinding Parts For Automatic Welding

    Science.gov (United States)

    Burley, Richard K.; Hoult, William S.

    1989-01-01

    Rollers guide grinding tool along prospective welding path. Skatelike fixture holds rotary grinder or file for machining large-diameter rings or ring segments in preparation for welding. Operator grasps handles to push rolling fixture along part. Rollers maintain precise dimensional relationship so grinding wheel cuts precise depth. Fixture-mounted grinder machines surface to quality sufficient for automatic welding; manual welding with attendant variations and distortion not necessary. Developed to enable automatic welding of parts, manual welding of which resulted in weld bead permeated with microscopic fissures.

  18. Prediction of Weld Residual Stress of Narrow Gap Welds

    International Nuclear Information System (INIS)

    Yang, Jun Seog; Huh, Nam Su

    2010-01-01

    The conventional welding technique such as shield metal arc welding has been mostly applied to the piping system of the nuclear power plants. It is well known that this welding technique causes the overheating and welding defects due to the large groove angle of weld. On the other hand, the narrow gap welding(NGW) technique has many merits, for instance, the reduction of welding time, the shrinkage of weld and the small deformation of the weld due to the small groove angle and welding bead width comparing with the conventional welds. These characteristics of NGW affect the deformation behavior and the distribution of welding residual stress of NGW, thus it is believed that the residual stress results obtained from conventional welding procedure may not be applied to structural integrity evaluation of NGW. In this paper, the welding residual stress of NGW was predicted using the nonlinear finite element analysis to simulate the thermal and mechanical effects of the NGW. The present results can be used as the important information to perform the flaw evaluation and to improve the weld procedure of NGW

  19. Evaluation of characterisation techniques for particulate weld fume morphology

    International Nuclear Information System (INIS)

    Sterjovski, Z.; Monaghan, B.J.; Norrish, J.

    2009-01-01

    An evaluation of three techniques: scanning electron microscopy (SEM); transmission electron microscopy (TEM); and laser diffraction (LD), was carried out to determine the most suitable technique for the particle-size measurement of particulate-welding fume collected during the robotic gas-metal-arc welding (GMAW) of plain-carbon steel. Particulate fume was deposited onto an Al stub positioned at a horizontal distance of 30 mm and a vertical height of 50 mm from the welding arc, and was then prepared for SEM, TEM and LD sizing. Results are presented for paniculate-welding fume collected for three welding voltages (20, 23 and 26 V) and two metal-transfer modes (dip and dip/globular). TEM imaging was found to be the most effective of the three sizing technique as it was able to resolve both fine nano-particles (5 ran diameter) and coarse nano-particles (>100 mn diameter). The TEM approach showed that results determined were reproducible and that the majority of fume particles produced at the welding voltages investigated were less than 40 nm in diameter. SEM (La B6 filament) images were shown to be inadequate for the quantitative-size analysis of paniculate-welding fume due to the limited resolution of the microscope (-40 nm). However. SEM images did confirm that at a welding voltage of 23 V the majority of particle sizes produced were less than 100 nm in diameter, and thus supported the conclusion that the individual fume particles are predominantly in the nanometre size range. LD gave unexpectedly large mean particle sizes and did not detect particles less than 180 run in diameter. It is concluded that the LD technique measures particle agglomerates and/or simultaneously monitors multiple particles in the beam path.

  20. Capabilities of infrared weld monitor

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, P.G.; Keske, J.S.; Leong, K.H.; Kornecki, G.

    1997-11-01

    A non-obtrusive pre-aligned, solid-state device has been developed to monitor the primary infrared emissions during laser welding. The weld monitor output is a 100-1000 mV signal that depends on the beam power and weld characteristics. The DC level of this signal is related to weld penetration, while AC portions of the output can be correlated with surface irregularities and part misalignment or contamination. Changes in DC behavior are also noted for both full and deep penetration welds. Full penetration welds are signified by an abrupt reduction in the weld monitor output. Bead on plate welds were made on steel, aluminum, and magnesium with both a CW CO{sub 2} laser and a pulsed Nd:YAG laser to explore the relationships between the weld characteristics and the weld monitor output.

  1. Dissimilar steel welding and overlay covering with nickel based alloys using SWAM (Shielded Metal Arc Welding) and GTAW (Gas Tungsten Arc Welding) processes in the nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    Arce Chilque, Angel Rafael [Centro Tecnico de Engenharia e Inovacao Empresarial Ltda., Belo Horizonte, MG (Brazil); Bracarense, Alexander Queiroz; Lima, Luciana Iglesias Lourenco [Federal University of Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Quinan, Marco Antonio Dutra; Schvartzman, Monica Maria de Abreu Mendonca [Nuclear Technology Development Centre (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Marconi, Guilherme [Federal Center of Technological Education (CEFET-MG), Belo Horizonte, MG (Brazil)

    2009-07-01

    This work presents the welding of dissimilar ferritic steel type A508 class 3 and austenitic stainless steel type AISI 316 L using Inconel{sup R} 600 (A182 and A82) and overlay covering with Inconel{sup R} 690 (A52) as filler metal. Dissimilar welds with these materials without defects and weldability problems such as hot, cold, reheat cracking and Ductility Dip Crack were obtained. Comparables mechanical properties to those of the base metal were found and signalized the efficiency of the welding procedure and thermal treatment selected and used. This study evidences the importance of meeting compromised properties between heat affected zone of the ferritic steel and the others regions presents in the dissimilar joint, to elaborate the dissimilar metal welding procedure specification and weld overlay. Metallographic studies with optical microscopy and Vickers microhardness were carried out to justified and support the results, showing the efficiency of the technique of elaboration of dissimilar metal welding procedure and overlay. The results are comparables and coherent with the results found by others. Some alternatives of welding procedures are proposed to attain the efficacy. Further studies are proposed like as metallographic studies of the fine microstructure, making use, for example, of scanning electron microscope (SEM adapted with an EDS) to explain looking to increase the resistance to primary water stress corrosion (PWSCC) in nuclear equipment. (author)

  2. Heat source model for welding process

    International Nuclear Information System (INIS)

    Doan, D.D.

    2006-10-01

    One of the major industrial stakes of the welding simulation relates to the control of mechanical effects of the process (residual stress, distortions, fatigue strength... ). These effects are directly dependent on the temperature evolutions imposed during the welding process. To model this thermal loading, an original method is proposed instead of the usual methods like equivalent heat source approach or multi-physical approach. This method is based on the estimation of the weld pool shape together with the heat flux crossing the liquid/solid interface, from experimental data measured in the solid part. Its originality consists in solving an inverse Stefan problem specific to the welding process, and it is shown how to estimate the parameters of the weld pool shape. To solve the heat transfer problem, the interface liquid/solid is modeled by a Bezier curve ( 2-D) or a Bezier surface (3-D). This approach is well adapted to a wide diversity of weld pool shapes met for the majority of the current welding processes (TIG, MlG-MAG, Laser, FE, Hybrid). The number of parameters to be estimated is weak enough, according to the cases considered from 2 to 5 in 20 and 7 to 16 in 3D. A sensitivity study leads to specify the location of the sensors, their number and the set of measurements required to a good estimate. The application of the method on test results of welding TIG on thin stainless steel sheets in emerging and not emerging configurations, shows that only one measurement point is enough to estimate the various weld pool shapes in 20, and two points in 3D, whatever the penetration is full or not. In the last part of the work, a methodology is developed for the transient analysis. It is based on the Duvaut's transformation which overpasses the discontinuity of the liquid metal interface and therefore gives a continuous variable for the all spatial domain. Moreover, it allows to work on a fixed mesh grid and the new inverse problem is equivalent to identify a source

  3. Robotics and remote handling in the nuclear industry

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    This book presents the papers given at a conference on the use of remote handling equipment in nuclear facilities. Topics considered at the conference included dose reduction, artificial intelligence in nuclear plant maintenance, robotic welding, uncertainty covariances, reactor operation and inspection, reactor maintenance and repair, uranium mining, fuel fabrication, reactor component manufacture, irradiated fuel and radioactive waste management, and radioisotope handling.

  4. Industrial robots in Europe - market, applications and developments

    Science.gov (United States)

    Schraft, R. D.

    1975-01-01

    Different companies involving a wide range of products and manufacturing processes were studied to define the requirements for industrial robots. A survey of all such automatic units offered on the world market was made to establish a data base. Principal applications include coating, spot welding, and loading and unloading operations.

  5. Welding method, and welding device for use therein, and method of analysis for evaluating welds

    NARCIS (Netherlands)

    Aendenroomer, A.J.; Den Ouden, G.; Xiao, Y.H.; Brabander, W.A.J.

    1995-01-01

    Described is a method of automatically welding pipes, comprising welding with a pulsation welding current and monitoring, by means of a sensor, the variations occurring in the arc voltage caused by weld pool oscillations. The occurrence of voltage variations with only frequency components below 100

  6. Effective programming of energy consuming industrial robot systems

    International Nuclear Information System (INIS)

    Trnka, K.; Pinter, T.; Knazik, M.; Bozek, P.

    2012-01-01

    This paper discusses the problem of effective motion planning for industrial robots. The first part dealt with current method for off-line motion planning. In the second part is presented the work done with one of the simulation system with automatic trajectory generation and off-line programming capability [4]. An spot welding process is involved. The practical application of this step strongly depends on the method for robot path optimization with high accuracy, thus, transform the path into a time and energy optimal robot program for the real world, which is discussed in the third step. (Authors)

  7. Self-protection Method for Flying Robots to Avoid Collision

    OpenAIRE

    Guosheng Wu; Luning Wang; Changyuan Fan; Xi Zhu

    2008-01-01

    This paper provides a new approach to solve the motion planning problems of flying robots in uncertain 3D dynamic environments. The robots controlled by this method can adaptively choose the fast way to avoid collision without information about the shapes and trajectories of obstacles. Based on sphere coordinates the new method accomplishes collision avoidance of flying robots without any other auxiliary positioning systems. The Self-protection System gives robots self-protection abilities to...

  8. Eddy current testing system for bottom mounted instrumentation welds

    Directory of Open Access Journals (Sweden)

    Kobayashi Noriyasu

    2015-01-01

    Full Text Available The capability of eddy current testing (ECT for the bottom mounted instrumentation (BMI weld area of reactor vessel in a pressurized water reactor was demonstrated by the developed ECT system and procedure. It is difficult to position and move the probe on the BMI weld area because the area has complexly curved surfaces. The space coordinates and the normal vectors at the scanning points were calculated as the scanning trajectory of probe based on the measured results of surface shape on the BMI mock-up. The multi-axis robot was used to move the probe on the mock-up. Each motion-axis position of the robot corresponding to each scanning point was calculated by the inverse kinematic algorithm. In the mock-up test, the probe was properly contacted with most of the weld surfaces. The artificial stress corrosion cracking of approximately 6 mm in length and the electrical-discharge machining slit of 0.5 mm in length, 1 mm in depth and 0.2 mm in width given on the weld surface were detected. From the probe output voltage, it was estimated that the average probe tilt angle on the surface under scanning was 2.6°.

  9. International Workshop and Summer School on Medical and Service Robotics

    CERN Document Server

    Bouri, Mohamed; Mondada, Francesco; Pisla, Doina; Rodic, Aleksandar; Helmer, Patrick

    2016-01-01

    Medical and Service Robotics integrate the most recent achievements in mechanics, mechatronics, computer science, haptic and teleoperation devices together with adaptive control algorithms. The book  includes topics such as surgery robotics, assist devices, rehabilitation technology, surgical instrumentation and Brain-Machine Interface (BMI) as examples for medical robotics. Autonomous cleaning, tending, logistics, surveying and rescue robots, and elderly and healthcare robots are typical examples of topics from service robotics. This is the Proceedings of the Third International Workshop on Medical and Service Robots, held in Lausanne, Switzerland in 2014. It presents an overview of current research directions and fields of interest. It is divided into three sections, namely 1) assistive and rehabilitation devices; 2) surgical robotics; and 3) educational and service robotics. Most contributions are strongly anchored on collaborations between technical and medical actors, engineers, surgeons and clinicians....

  10. Mobile Robots for Hospital Logistics

    DEFF Research Database (Denmark)

    Özkil, Ali Gürcan

    services to maintain the quality of healthcare provided. Logistics is the most resource demanding service in a hospital. The scale of the transportation tasks is huge and the material flow in a hospital is comparable to that of a factory. We believe that these transportation tasks, to a great extent, can...... be and will be automated using mobile robots. This talk consequently addresses the key technical issues of implementing service robots in hospitals. In simple terms, a robotic system for automating hospital logistics has to be reliable, adaptable and scalable. Robots have to be semi-autonomous, and should reliably...... navigate in large and dynamic environments in the hospital. The complexity of the problem has to be manageable, and the solutions have to be flexible, so that the system can be applicable in real world settings. This talk summarizes the efforts to address these issues. Upon the analysis...

  11. Sensory Robot Gripper

    DEFF Research Database (Denmark)

    Drimus, Alin

    The project researches and proposes a tactile sensor system for equipping robotic grippers, thus giving them a sense of touch. We start by reviewing work that covers the building of tactile sensors and we focus on the flexible sensors with multiple sensing elements. As the piezoresistive, capacit......The project researches and proposes a tactile sensor system for equipping robotic grippers, thus giving them a sense of touch. We start by reviewing work that covers the building of tactile sensors and we focus on the flexible sensors with multiple sensing elements. As the piezoresistive......, such as establishing of contact, release of contact or slip. The proposed applications are just a few examples of the advantages of equipping robotic grippers with such a tactile sensor system, that is robust, fast, affordable, adaptable to any kind of gripper and has properties similar to the human sense of touch....... Based on experimental validation, we are confident that our proposed tactile sensor solution can be successfully employed in other application areas like reactive grasping, exploration of unknown objects, slip avoidance, dexterous manipulation or service robotics....

  12. Welding processes handbook

    CERN Document Server

    Weman, Klas

    2003-01-01

    Deals with the main commercially significant and commonly used welding processes. This title takes the student or novice welder through the individual steps involved in each process in an easily understood way. It covers many of the requirements referred to in European Standards including EN719, EN 729, EN 729 and EN 287.$bWelding processes handbook is a concise, explanatory guide to the main commercially significant and commonly-used welding processes. It takes the novice welder or student through the individual steps involved in each process in a clear and easily understood way. It is intended to provide an up-to-date reference to the major applications of welding as they are used in industry. The contents have been arranged so that it can be used as a textbook for European welding courses in accordance with guidelines from the European Welding Federation. Welding processes and equipment necessary for each process are described so that they can be applied to all instruction levels required by the EWF and th...

  13. Space Robotics Challenge

    Data.gov (United States)

    National Aeronautics and Space Administration — The Space Robotics Challenge seeks to infuse robot autonomy from the best and brightest research groups in the robotics community into NASA robots for future...

  14. Robotic surgery

    Science.gov (United States)

    ... with this type of surgery give it some advantages over standard endoscopic techniques. The surgeon can make ... Elsevier Saunders; 2015:chap 87. Muller CL, Fried GM. Emerging technology in surgery: Informatics, electronics, robotics. In: ...

  15. Robotic parathyroidectomy.

    Science.gov (United States)

    Okoh, Alexis Kofi; Sound, Sara; Berber, Eren

    2015-09-01

    Robotic parathyroidectomy has recently been described. Although the procedure eliminates the neck scar, it is technically more demanding than the conventional approaches. This report is a review of the patients' selection criteria, technique, and outcomes. © 2015 Wiley Periodicals, Inc.

  16. Light Robotics

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    Light Robotics - Structure-Mediated Nanobiophotonics covers the latest means of sculpting of both light and matter for achieving bioprobing and manipulation at the smallest scales. The synergy between photonics, nanotechnology and biotechnology spans the rapidly growing field of nanobiophotonics...

  17. The Tactile Ethics of Soft Robotics: Designing Wisely for Human-Robot Interaction.

    Science.gov (United States)

    Arnold, Thomas; Scheutz, Matthias

    2017-06-01

    Soft robots promise an exciting design trajectory in the field of robotics and human-robot interaction (HRI), promising more adaptive, resilient movement within environments as well as a safer, more sensitive interface for the objects or agents the robot encounters. In particular, tactile HRI is a critical dimension for designers to consider, especially given the onrush of assistive and companion robots into our society. In this article, we propose to surface an important set of ethical challenges for the field of soft robotics to meet. Tactile HRI strongly suggests that soft-bodied robots balance tactile engagement against emotional manipulation, model intimacy on the bonding with a tool not with a person, and deflect users from personally and socially destructive behavior the soft bodies and surfaces could normally entice.

  18. Soft Legged Wheel-Based Robot with Terrestrial Locomotion Abilities

    Directory of Open Access Journals (Sweden)

    Ali Sadeghi

    2016-12-01

    Full Text Available In recent years robotics has been influenced by a new approach, soft-robotics, bringing the idea that safe interaction with user and more adaptation to the environment can be achieved by exploiting easily deformable materials and flexible components in the structure of robots. In 2016, the soft-robotics community has promoted a new robotics challenge, named RoboSoft Grand Challenge, with the aim of bringing together different opinions on the usefulness and applicability of softness and compliancy in robotics. In this paper we describe the design and implementation of a terrestrial robot based on two soft legged wheels. The tasks predefined by the challenge were set as targets in the robot design, which finally succeeded to accomplish all the tasks. The wheels of the robot can passively climb over stairs and adapt to slippery grounds using two soft legs embedded in their structure. The soft legs, fabricated by integration of soft and rigid materials and mounted on the circumference of a conventional wheel, succeed to enhance its functionality and easily adapt to unknown grounds. The robot has a semi stiff tail that helps in the stabilization and climbing of stairs. An active wheel is embedded at the extremity of the tail in order to increase the robot maneuverability in narrow environments. Moreover two parallelogram linkages let the robot to reconfigure and shrink its size allowing entering inside gates smaller than its initial dimensions.

  19. Thermal stir welding process

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2012-01-01

    A welding method is provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  20. Thermal stir welding apparatus

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2011-01-01

    A welding method and apparatus are provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  1. Review of Welding Terminology

    Directory of Open Access Journals (Sweden)

    Angelika Petrėtienė

    2011-04-01

    Full Text Available The paper discusses welding terms in accordance with the Lithuanian standard LST EN 1792 „Welding. The multilingual list of welding terms and similar processes”, „The Russian–Lithuanian dictionary of the terms of mechanical engineering technology and welding“ and the examples from postgraduates‘ final works. It analyses the infringement of lexical, word-building and morphological rules. First-year students should already be familiar with the standardized terms of their speciality. More active propagation of the terms should help to avoid terminology mistakes in various scientific spheres.

  2. Half bead welding technique

    International Nuclear Information System (INIS)

    Canonico, D.A.; Holz, P.P.

    1978-05-01

    The ORNL has employed the Section XI half-bead procedure for six repair welds. Table 2 identifies the repairs and the components upon which they were accomplished. The weld repairs were performed to permit us to evaluate material properties, residual stresses, weld repair procedures, and structural behavior of repaired pressure vessels. As a consequence of our study we concluded that when the half bead procedure is correctly applied: (1) there is no metallurgical degradation of the base material, (2) residual stresses of yield point magnitude will be present, and (3) the structural integrity of the pressure vessel is not impaired at Charpy V-notch upper shelf temperatures

  3. Vision Guided Intelligent Robot Design And Experiments

    Science.gov (United States)

    Slutzky, G. D.; Hall, E. L.

    1988-02-01

    The concept of an intelligent robot is an important topic combining sensors, manipulators, and artificial intelligence to design a useful machine. Vision systems, tactile sensors, proximity switches and other sensors provide the elements necessary for simple game playing as well as industrial applications. These sensors permit adaption to a changing environment. The AI techniques permit advanced forms of decision making, adaptive responses, and learning while the manipulator provides the ability to perform various tasks. Computer languages such as LISP and OPS5, have been utilized to achieve expert systems approaches in solving real world problems. The purpose of this paper is to describe several examples of visually guided intelligent robots including both stationary and mobile robots. Demonstrations will be presented of a system for constructing and solving a popular peg game, a robot lawn mower, and a box stacking robot. The experience gained from these and other systems provide insight into what may be realistically expected from the next generation of intelligent machines.

  4. Robotics in Orthopedics: A Brave New World.

    Science.gov (United States)

    Parsley, Brian S

    2018-02-16

    Future health-care projection projects a significant growth in population by 2020. Health care has seen an exponential growth in technology to address the growing population with the decreasing number of physicians and health-care workers. Robotics in health care has been introduced to address this growing need. Early adoption of robotics was limited because of the limited application of the technology, the cumbersome nature of the equipment, and technical complications. A continued improvement in efficacy, adaptability, and cost reduction has stimulated increased interest in robotic-assisted surgery. The evolution in orthopedic surgery has allowed for advanced surgical planning, precision robotic machining of bone, improved implant-bone contact, optimization of implant placement, and optimization of the mechanical alignment. The potential benefits of robotic surgery include improved surgical work flow, improvements in efficacy and reduction in surgical time. Robotic-assisted surgery will continue to evolve in the orthopedic field. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Control of autonomous robot using neural networks

    Science.gov (United States)

    Barton, Adam; Volna, Eva

    2017-07-01

    The aim of the article is to design a method of control of an autonomous robot using artificial neural networks. The introductory part describes control issues from the perspective of autonomous robot navigation and the current mobile robots controlled by neural networks. The core of the article is the design of the controlling neural network, and generation and filtration of the training set using ART1 (Adaptive Resonance Theory). The outcome of the practical part is an assembled Lego Mindstorms EV3 robot solving the problem of avoiding obstacles in space. To verify models of an autonomous robot behavior, a set of experiments was created as well as evaluation criteria. The speed of each motor was adjusted by the controlling neural network with respect to the situation in which the robot was found.

  6. A ROBOT AND A METHOD OF CONTROLLING A ROBOT

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to a robot comprising a horizontal or horizontally slanted transparent experiment layer being adapted to support items at arbitrary positions on or in the experiment layer, and a moveable sensor arranged below the transparent experimental layer said sensor being...

  7. Robot development for nuclear material processing

    International Nuclear Information System (INIS)

    Pedrotti, L.R.; Armantrout, G.A.; Allen, D.C.; Sievers, R.H. Sr.

    1991-07-01

    The Department of Energy is seeking to modernize its special nuclear material (SNM) production facilities and concurrently reduce radiation exposures and process and incidental radioactive waste generated. As part of this program, Lawrence Livermore National Laboratory (LLNL) lead team is developing and adapting generic and specific applications of commercial robotic technologies to SNM pyrochemical processing and other operations. A working gantry robot within a sealed processing glove box and a telerobot control test bed are manifestations of this effort. This paper describes the development challenges and progress in adapting processing, robotic, and nuclear safety technologies to the application. 3 figs

  8. Recent advances in robotics

    International Nuclear Information System (INIS)

    Beni, G.; Hackwood, S.

    1984-01-01

    Featuring 10 contributions, this volume offers a state-of-the-art report on robotic science and technology. It covers robots in modern industry, robotic control to help the disabled, kinematics and dynamics, six-legged walking robots, a vector analysis of robot manipulators, tactile sensing in robots, and more

  9. Recent developments in pipeline welding practice

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Fourteen chapters are included: overview of pipeline welding systems and quality assurance, CRC automatic welding system, H.C. Price Co. automatic welding system, semi-automatic MIG-welding process, partial penetration welding of steel pipes for gas distribution, construction procedures and quality control in offshore pipeline construction, welding in repair and maintenance of gas transmission pipelines, British Gas studies of welding on pressurized gas transmission pipelines, hot tapping pipelines, underwater welding for offshore pipelines and associated equipment, radial friction welding, material composition vs weld properties, review of NDT of pipeline welds, and safety assurance in pipeline construction. A bibliography of approximately 150 references is included, arranged according to subject and year.

  10. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  11. Residual stress by repair welds

    International Nuclear Information System (INIS)

    Mochizuki, Masahito; Toyoda, Masao

    2003-01-01

    Residual stress by repair welds is computed using the thermal elastic-plastic analysis with phase-transformation effect. Coupling phenomena of temperature, microstructure, and stress-strain fields are simulated in the finite-element analysis. Weld bond of a plate butt-welded joint is gouged and then deposited by weld metal in repair process. Heat source is synchronously moved with the deposition of the finite-element as the weld deposition. Microstructure is considered by using CCT diagram and the transformation behavior in the repair weld is also simulated. The effects of initial stress, heat input, and weld length on residual stress distribution are studied from the organic results of numerical analysis. Initial residual stress before repair weld has no influence on the residual stress after repair treatment near weld metal, because the initial stress near weld metal releases due to high temperature of repair weld and then stress by repair weld regenerates. Heat input has an effect for residual stress distribution, for not its magnitude but distribution zone. Weld length should be considered reducing the magnitude of residual stress in the edge of weld bead; short bead induces high tensile residual stress. (author)

  12. Markov Chain Monte Carlo (MCMC) methods for parameter estimation of a novel hybrid redundant robot

    International Nuclear Information System (INIS)

    Wang Yongbo; Wu Huapeng; Handroos, Heikki

    2011-01-01

    This paper presents a statistical method for the calibration of a redundantly actuated hybrid serial-parallel robot IWR (Intersector Welding Robot). The robot under study will be used to carry out welding, machining, and remote handing for the assembly of vacuum vessel of International Thermonuclear Experimental Reactor (ITER). The robot has ten degrees of freedom (DOF), among which six DOF are contributed by the parallel mechanism and the rest are from the serial mechanism. In this paper, a kinematic error model which involves 54 unknown geometrical error parameters is developed for the proposed robot. Based on this error model, the mean values of the unknown parameters are statistically analyzed and estimated by means of Markov Chain Monte Carlo (MCMC) approach. The computer simulation is conducted by introducing random geometric errors and measurement poses which represent the corresponding real physical behaviors. The simulation results of the marginal posterior distributions of the estimated model parameters indicate that our method is reliable and robust.

  13. INDUSTRIAL ROBOT REPEATABILITY TESTING WITH HIGH SPEED CAMERA PHANTOM V2511

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2016-12-01

    Full Text Available Apart from accuracy, one of the parameters describing industrial robots is positioning accuracy. The parameter in question, which is the subject of this paper, is often the decisive factor determining whether to apply a given robot to perform certain tasks or not. Articulated robots are predominantly used in such processes as: spot weld-ing, transport of materials and other welding applications, where high positioning repeatability is required. It is therefore essential to recognise the parameter in question and to control it throughout the operation of the robot. This paper presents methodology for robot positioning accuracy measurements based on vision technique. The measurements were conducted with Phantom v2511 high-speed camera and TEMA Motion software, for motion analysis. The object of the measurements was a 6-axis Yaskawa Motoman HP20F industrial robot. The results of measurements obtained in tests provided data for the calculation of positioning accuracy of the robot, which was then juxtaposed against robot specifications. Also analysed was the impact of the direction of displacement on the value of attained pose errors. Test results are given in a graphic form.

  14. Welding of refractory alloys

    International Nuclear Information System (INIS)

    Lessmann, G.G.

    1984-01-01

    This review primarily summarizes welding evaluations supported by NASA-Lewis Research Center in the 1960s. A literature search run in preparation for this review indicates that more recent work is modest by comparison. Hence, this review restates these accomplishments briefly and addresses opportunities which have evolved in welding technology (such as lasers) in the intervening decade. Emphasis in this review is given to tantalum- and niobium-base alloys. Considerable work was also done to assure that a consistent comparison was made with tungsten. A wide variety of candidate alloys derived primarily from developments directed at aircraft propulsion applications were available. Early efforts by NASA were directed at screening studies to select promising structural alloys for the space power application. This objective required fine tuning of welding procedures, e.g., the demonstration of stringent standards for control of welding atmosphere to assure good corrosion resistance in liquid alkali metals. 16 figures, 6 tables

  15. Multispot fiber laser welding

    DEFF Research Database (Denmark)

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been examined and evaluated. It is found that both diamond turned DOE’s in zinc sulphide and multilevel etched DOE’s (Diffractive Optical Elements) in fused silica have a good performance. Welding with multiple beams in a butt joint configuration has been tested. Results are presented, showing it has...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...

  16. Friction stir welding tool

    Science.gov (United States)

    Tolle,; Charles R. , Clark; Denis E. , Barnes; Timothy, A [Ammon, ID

    2008-04-15

    A friction stir welding tool is described and which includes a shank portion; a shoulder portion which is releasably engageable with the shank portion; and a pin which is releasably engageable with the shoulder portion.

  17. Diffractive beam shaping for enhanced laser polymer welding

    Science.gov (United States)

    Rauschenberger, J.; Vogler, D.; Raab, C.; Gubler, U.

    2015-03-01

    Laser welding of polymers increasingly finds application in a large number of industries such as medical technology, automotive, consumer electronics, textiles or packaging. More and more, it replaces other welding technologies for polymers, e. g. hot-plate, vibration or ultrasonic welding. At the same rate, demands on the quality of the weld, the flexibility of the production system and on processing speed have increased. Traditionally, diode lasers were employed for plastic welding with flat-top beam profiles. With the advent of fiber lasers with excellent beam quality, the possibility to modify and optimize the beam profile by beam-shaping elements has opened. Diffractive optical elements (DOE) can play a crucial role in optimizing the laser intensity profile towards the optimal M-shape beam for enhanced weld seam quality. We present results on significantly improved weld seam width constancy and enlarged process windows compared to Gaussian or flat-top beam profiles. Configurations in which the laser beam diameter and shape can be adapted and optimized without changing or aligning the laser, fiber-optic cable or optical head are shown.

  18. Laser assisted robotic surgery in cornea transplantation

    Science.gov (United States)

    Rossi, Francesca; Micheletti, Filippo; Magni, Giada; Pini, Roberto; Menabuoni, Luca; Leoni, Fabio; Magnani, Bernardo

    2017-03-01

    Robotic surgery is a reality in several surgical fields, such as in gastrointestinal surgery. In ophthalmic surgery the required high spatial precision is limiting the application of robotic system, and even if several attempts have been designed in the last 10 years, only some application in retinal surgery were tested in animal models. The combination of photonics and robotics can really open new frontiers in minimally invasive surgery, improving the precision, reducing tremor, amplifying scale of motion, and automating the procedure. In this manuscript we present the preliminary results in developing a vision guided robotic platform for laser-assisted anterior eye surgery. The robotic console is composed by a robotic arm equipped with an "end effector" designed to deliver laser light to the anterior corneal surface. The main intended application is for laser welding of corneal tissue in laser assisted penetrating keratoplasty and endothelial keratoplasty. The console is equipped with an integrated vision system. The experiment originates from a clear medical demand in order to improve the efficacy of different surgical procedures: when the prototype will be optimized, other surgical areas will be included in its application, such as neurosurgery, urology and spinal surgery.

  19. Underwater Welding Techniques

    OpenAIRE

    Esam F. Alajmi; Ahmad A. Alqenaei

    2017-01-01

    Welding demand in offshore and marine applications is increased with the increasing in oil and gas activities as well as increasing in the marine transportation and industrial applications. Applications of underwater welding well be increased in Kuwait in the coming years due to the strategic directive of the country toward starting the offshore oil and gas exploration and production, and the increase in marine transportation projects. Therefore, there is a need to understand the concept of u...

  20. A mobile robot with parallel kinematics constructed under requirements for assembling and machining of the ITER vacuum vessel

    International Nuclear Information System (INIS)

    Pessi, P.; Huapeng Wu; Handroos, H.; Jones, L.

    2006-01-01

    ITER sectors require more stringent tolerances ± 5 mm than normally expected for the size of structure involved. The walls of ITER sectors are made of 60 mm thick stainless steel and are joined together by high efficiency structural and leak tight welds. In addition to the initial vacuum vessel assembly, sectors may have to be replaced for repair. Since commercially available machines are too heavy for the required machining operations and the lifting of a possible e-beam gun column system, and conventional robots lack the stiffness and accuracy in such machining condition, a new flexible, lightweight and mobile robotic machine is being considered. For the assembly of the ITER vacuum vessel sector, precise positioning of welding end-effectors, at some distance in a confined space from the available supports, will be required, which is not possible using conventional machines or robots. This paper presents a special robot, able to carry out welding and machining processes from inside the ITER vacuum vessel, consisting of a ten-degree-of-freedom parallel robot mounted on a carriage driven by electric motor/gearbox on a track. The robot consists of a Stewart platform based parallel mechanism. Water hydraulic cylinders are used as actuators to reach six degrees of freedom for parallel construction. Two linear and two rotational motions are used for enlargement the workspace of the manipulator. The robot carries both welding gun such as a TIG, hybrid laser or e-beam welding gun to weld the inner and outer walls of the ITER vacuum vessel sectors and machining tools to cut and milling the walls with necessary accuracy, it can also carry other tools and material to a required position inside the vacuum vessel . For assembling an on line six degrees of freedom seam finding algorithm has been developed, which enables the robot to find welding seam automatically in a very complex environment. In the machining multi flexible machining processes carried out automatically by

  1. Report of the results of the fiscal 1997 regional consortium R and D project. Regional consortium energy field / R and D of a task adaptation type group architecture transfer robot system, TRIPTERS (first fiscal year); 1997 nendo chiiki consortium kenkyu kaihatsu jigyo. Chiiki consortium energy bun`ya / task tekigogata gun kosei hanso robot system TRIPTERS no kaihatsu kenkyu (daiichi nendo) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper stated the fiscal 1997 result of the development of a task adaptation type group architecture transfer robot system (TRIPTERS) which can cope with changes in carrying task rapidly and flexibly. R and D were conducted mainly of various functional modules, the operation management technology which enables group architecture, and the basic design of a standardized transfer robot. As to the positioning, studied were the construction of the basic hardware of laser position measuring device, and the application method. Concerning the cooperative carrying, conducted were securing of positioning accuracy of matters to be carried, high speed heavy transfer control, and design of dead reckoning system. Relating to the operation management, passable areas were divided into more than one zones, and the effective path reservation method was constructed so that one and the same zone is not occupied. As to the environmental recognition/obstacle avoidance, developed were actual hour/distance acquisition equipment, and autonomous cars running according to the directions of the color sign recognition system by stereo CCD camera. Also conducted were the development of methods to recognize the distance to obstacles and to discriminate areas, the development of mobile sensor, and the basic experiment on running of the demonstration machine. 44 refs., 153 figs., 15 tabs.

  2. THE FORMATION OF BIMETALLIC CONNECTION IN WELDER DEPOSITION UNDER LASER WELDING WITH THE FILLER WIRE FEED

    Directory of Open Access Journals (Sweden)

    A. P. Yelistratov

    2017-01-01

    Full Text Available The metallurgical and technological features of welding deposition in a robotic unit with a semiconductor laser are analyzed. The prospects of using beam with low energy density in the spot heating for applying metallic layers using filler wire are shown. 

  3. Soft Robotics Week

    CERN Document Server

    Rossiter, Jonathan; Iida, Fumiya; Cianchetti, Matteo; Margheri, Laura

    2017-01-01

    This book offers a comprehensive, timely snapshot of current research, technologies and applications of soft robotics. The different chapters, written by international experts across multiple fields of soft robotics, cover innovative systems and technologies for soft robot legged locomotion, soft robot manipulation, underwater soft robotics, biomimetic soft robotic platforms, plant-inspired soft robots, flying soft robots, soft robotics in surgery, as well as methods for their modeling and control. Based on the results of the second edition of the Soft Robotics Week, held on April 25 – 30, 2016, in Livorno, Italy, the book reports on the major research lines and novel technologies presented and discussed during the event.

  4. Generation rate of carbon monoxide from CO2 arc welding.

    Science.gov (United States)

    Ojima, Jun

    2013-01-01

    CO poisoning has been a serious industrial hazard in Japanese workplaces. Although incomplete combustion is the major cause of CO generation, there is a risk of CO poisoning during some welding operations. The aim of the present study was to evaluate the generation rate of CO from CO2 arc welding under controlled laboratory conditions and estimate the ventilation requirements for the prevention of CO poisoning. Bead on plate welding was carried out with an automatic welding robot on a rolled steel base metal under several conditions. The concentration of emitted CO from the welding was measured by a real-time CO monitor in a well-ventilated laboratory that was free from ambient CO contamination. The generation rate of CO was obtained from the three measurements-the flow rate of the welding exhaust gas, CO concentration in the exhaust gas and the arcing time. Then the ventilation requirement to prevent CO poisoning was calculated. The generation rate of CO was found to be 386-883 ml/min with a solid wire and 331-1,293 ml/min with a flux cored wire respectively. It was found that the CO concentration in a room would be maintained theoretically below the OSHA PEL (50 ppm) providing the ventilation rate in the room was 6.6-25.9 m3/min. The actual ventilation requirement was then estimated to be 6.6-259 m3/min considering incomplete mixing. In order to prevent CO poisoning, some countermeasures against gaseous emission as well as welding fumes should be taken eagerly.

  5. Rehabilitation robotics.

    Science.gov (United States)

    Krebs, H I; Volpe, B T

    2013-01-01

    This chapter focuses on rehabilitation robotics which can be used to augment the clinician's toolbox in order to deliver meaningful restorative therapy for an aging population, as well as on advances in orthotics to augment an individual's functional abilities beyond neurorestoration potential. The interest in rehabilitation robotics and orthotics is increasing steadily with marked growth in the last 10 years. This growth is understandable in view of the increased demand for caregivers and rehabilitation services escalating apace with the graying of the population. We provide an overview on improving function in people with a weak limb due to a neurological disorder who cannot properly control it to interact with the environment (orthotics); we then focus on tools to assist the clinician in promoting rehabilitation of an individual so that s/he can interact with the environment unassisted (rehabilitation robotics). We present a few clinical results occurring immediately poststroke as well as during the chronic phase that demonstrate superior gains for the upper extremity when employing rehabilitation robotics instead of usual care. These include the landmark VA-ROBOTICS multisite, randomized clinical study which demonstrates clinical gains for chronic stroke that go beyond usual care at no additional cost. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Medical robotics.

    Science.gov (United States)

    Ferrigno, Giancarlo; Baroni, Guido; Casolo, Federico; De Momi, Elena; Gini, Giuseppina; Matteucci, Matteo; Pedrocchi, Alessandra

    2011-01-01

    Information and communication technology (ICT) and mechatronics play a basic role in medical robotics and computer-aided therapy. In the last three decades, in fact, ICT technology has strongly entered the health-care field, bringing in new techniques to support therapy and rehabilitation. In this frame, medical robotics is an expansion of the service and professional robotics as well as other technologies, as surgical navigation has been introduced especially in minimally invasive surgery. Localization systems also provide treatments in radiotherapy and radiosurgery with high precision. Virtual or augmented reality plays a role for both surgical training and planning and for safe rehabilitation in the first stage of the recovery from neurological diseases. Also, in the chronic phase of motor diseases, robotics helps with special assistive devices and prostheses. Although, in the past, the actual need and advantage of navigation, localization, and robotics in surgery and therapy has been in doubt, today, the availability of better hardware (e.g., microrobots) and more sophisticated algorithms(e.g., machine learning and other cognitive approaches)has largely increased the field of applications of these technologies,making it more likely that, in the near future, their presence will be dramatically increased, taking advantage of the generational change of the end users and the increasing request of quality in health-care delivery and management.

  7. Implementation of an Outer Can Welding System for Savannah River Site FB-Line

    International Nuclear Information System (INIS)

    Howard, S.R.

    2003-01-01

    This paper details three phases of testing to confirm use of a Gas Tungsten Arc (GTA) system for closure welding the 3013 outer container used for stabilization/storage of plutonium metals and oxides. The outer container/lid closure joint was originally designed for laser welding, but for this application, the gas tungsten arc (GTA) welding process has been adapted. The testing progressed in three phases: (1) system checkout to evaluate system components for operational readiness, (2) troubleshooting to evaluate high weld failure rates and develop corrective techniques, and (3) pre-installation acceptance testing

  8. Automatic welding machine for piping

    International Nuclear Information System (INIS)

    Yoshida, Kazuhiro; Koyama, Takaichi; Iizuka, Tomio; Ito, Yoshitoshi; Takami, Katsumi.

    1978-01-01

    A remotely controlled automatic special welding machine for piping was developed. This machine is utilized for long distance pipe lines, chemical plants, thermal power generating plants and nuclear power plants effectively from the viewpoint of good quality control, reduction of labor and good controllability. The function of this welding machine is to inspect the shape and dimensions of edge preparation before welding work by the sense of touch, to detect the temperature of melt pool, inspect the bead form by the sense of touch, and check the welding state by ITV during welding work, and to grind the bead surface and inspect the weld metal by ultrasonic test automatically after welding work. The construction of this welding system, the main specification of the apparatus, the welding procedure in detail, the electrical source of this welding machine, the cooling system, the structure and handling of guide ring, the central control system and the operating characteristics are explained. The working procedure and the effect by using this welding machine, and the application to nuclear power plants and the other industrial field are outlined. The HIDIC 08 is used as the controlling computer. This welding machine is useful for welding SUS piping as well as carbon steel piping. (Nakai, Y.)

  9. Study on laser welding of austenitic stainless steel by varying incident angle of pulsed laser beam

    Science.gov (United States)

    Kumar, Nikhil; Mukherjee, Manidipto; Bandyopadhyay, Asish

    2017-09-01

    In the present work, AISI 304 stainless steel sheets are laser welded in butt joint configuration using a robotic control 600 W pulsed Nd:YAG laser system. The objective of the work is of twofold. Firstly, the study aims to find out the effect of incident angle on the weld pool geometry, microstructure and tensile property of the welded joints. Secondly, a set of experiments are conducted, according to response surface design, to investigate the effects of process parameters, namely, incident angle of laser beam, laser power and welding speed, on ultimate tensile strength by developing a second order polynomial equation. Study with three different incident angle of laser beam 89.7 deg, 85.5 deg and 83 deg has been presented in this work. It is observed that the weld pool geometry has been significantly altered with the deviation in incident angle. The weld pool shape at the top surface has been altered from semispherical or nearly spherical shape to tear drop shape with decrease in incident angle. Simultaneously, planer, fine columnar dendritic and coarse columnar dendritic structures have been observed at 89.7 deg, 85.5 deg and 83 deg incident angle respectively. Weld metals with 85.5 deg incident angle has higher fraction of carbide and δ-ferrite precipitation in the austenitic matrix compared to other weld conditions. Hence, weld metal of 85.5 deg incident angle achieved higher micro-hardness of ∼280 HV and tensile strength of 579.26 MPa followed by 89.7 deg and 83 deg incident angle welds. Furthermore, the predicted maximum value of ultimate tensile strength of 580.50 MPa has been achieved for 85.95 deg incident angle using the developed equation where other two optimum parameter settings have been obtained as laser power of 455.52 W and welding speed of 4.95 mm/s. This observation has been satisfactorily validated by three confirmatory tests.

  10. Generic robot architecture

    Science.gov (United States)

    Bruemmer, David J [Idaho Falls, ID; Few, Douglas A [Idaho Falls, ID

    2010-09-21

    The present invention provides methods, computer readable media, and apparatuses for a generic robot architecture providing a framework that is easily portable to a variety of robot platforms and is configured to provide hardware abstractions, abstractions for generic robot attributes, environment abstractions, and robot behaviors. The generic robot architecture includes a hardware abstraction level and a robot abstraction level. The hardware abstraction level is configured for developing hardware abstractions that define, monitor, and control hardware modules available on a robot platform. The robot abstraction level is configured for defining robot attributes and provides a software framework for building robot behaviors from the robot attributes. Each of the robot attributes includes hardware information from at least one hardware abstraction. In addition, each robot attribute is configured to substantially isolate the robot behaviors from the at least one hardware abstraction.

  11. 'Filigree Robotics'

    DEFF Research Database (Denmark)

    2016-01-01

    -scale 3D printed ceramics accompanied by prints, videos and ceramic probes, which introduce the material and design processes of the project.'Filigree Robotics' experiments with a combination of the traditional ceramic technique of ‘Overforming’ with 3d Laserscan and Robotic extrusion technique...... application of reflectivity after an initial 3d print. The consideration and integration of this material practice into a digital workflow took place in an interdisciplinary collaboration of Ceramicist Flemming Tvede Hansen from KADK Superformlab and architectural researchers from CITA (Martin Tamke, Henrik...... to the creation of the form and invites for experimentation. In Filigree Robotics we combine the crafting of the mold with a parallel running generative algorithm, which is fed by a constant laserscan of the 3d surface. This algorithm, analyses the topology of the mold, identifies high and low points and uses...

  12. Alternate Welding Processes for In-Service Welding

    Science.gov (United States)

    2009-04-24

    Conducting weld repairs and attaching hot tap tees onto pressurized pipes has the advantage of avoiding loss of service and revenue. However, the risks involved with in-service welding need to be managed by ensuring that welding is performed in a rep...

  13. Certification of a weld produced by friction stir welding

    Science.gov (United States)

    Obaditch, Chris; Grant, Glenn J

    2013-10-01

    Methods, devices, and systems for providing certification of friction stir welds are disclosed. A sensor is used to collect information related to a friction stir weld. Data from the sensor is compared to threshold values provided by an extrinsic standard setting organizations using a certification engine. The certification engine subsequently produces a report on the certification status of the weld.

  14. Cloud Robotics Platforms

    Directory of Open Access Journals (Sweden)

    Busra Koken

    2015-01-01

    Full Text Available Cloud robotics is a rapidly evolving field that allows robots to offload computation-intensive and storage-intensive jobs into the cloud. Robots are limited in terms of computational capacity, memory and storage. Cloud provides unlimited computation power, memory, storage and especially collaboration opportunity. Cloud-enabled robots are divided into two categories as standalone and networked robots. This article surveys cloud robotic platforms, standalone and networked robotic works such as grasping, simultaneous localization and mapping (SLAM and monitoring.

  15. An Ultralightweight and Living Legged Robot.

    Science.gov (United States)

    Vo Doan, Tat Thang; Tan, Melvin Y W; Bui, Xuan Hien; Sato, Hirotaka

    2018-02-01

    In this study, we describe the most ultralightweight living legged robot to date that makes it a strong candidate for a search and rescue mission. The robot is a living beetle with a wireless electronic backpack stimulator mounted on its thorax. Inheriting from the living insect, the robot employs a compliant body made of soft actuators, rigid exoskeletons, and flexure hinges. Such structure would allow the robot to easily adapt to any complex terrain due to the benefit of soft interface, self-balance, and self-adaptation of the insect without any complex controller. The antenna stimulation enables the robot to perform not only left/right turning but also backward walking and even cessation of walking. We were also able to grade the turning and backward walking speeds by changing the stimulation frequency. The power required to drive the robot is low as the power consumption of the antenna stimulation is in the order of hundreds of microwatts. In contrast to the traditional legged robots, this robot is of low cost, easy to construct, simple to control, and has ultralow power consumption.

  16. A Plug and Produce Framework for Industrial Collaborative Robots

    DEFF Research Database (Denmark)

    Schou, Casper; Madsen, Ole

    2017-01-01

    Collaborative robots are today ever more interesting in response to the increasing need for agile manufacturing equipment. Contrary to traditional industrial robots, collaborative robots are intended for working in dynamic environments alongside the production staff. To cope with the dynamic...... environment and workflow, new configuration and control methods are needed compared to those of traditional industrial robots. The new methods should enable shop floor operators to reconfigure the robot. This article presents a plug and produce framework for industrial collaborative robots. The article...... focuses on the control framework enabling quick and easy exchange of hardware modules as an approach to achieving plug and produce. To solve this, an agent-based system is proposed building on top of the robot operating system. The framework enables robot operating system packages to be adapted...

  17. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

    1976-01-01

    The ultrasonic examination of austenitic stainless steel weld metal has always been regarded as a difficult proposition because of the large and variable ultrasonic attenuations and back scattering obtained from apparently similar weld deposits. The work to be described shows how the existence of a fibre texture within each weld deposit (as a result of epitaxial growth through successive weld beads) produces a systematic variation in the ultrasonic attenuation coefficient and the velocity of sound, depending upon the angle between the ultrasonic beam and the fibre axis. Development work has shown that it is possible to adjust the welding parameters to ensure that the crystallographic texture within each weld is compatible with improved ultrasonic transmission. The application of the results to the inspection of a specific weld in type 316 weld metal is described

  18. Arc-weld pool interactions

    International Nuclear Information System (INIS)

    Glickstein, S.S.

    1978-08-01

    The mechanisms involved in arc-weld pool interactions are extremely complex and no complete theory is presently available to describe much of the phenomena observed during welding. For the past several years, experimental and analytical studies have been undertaken at the Bettis Atomic Power Laboratory to increase basic understanding of the gas tungsten arc welding process. These studies have included experimental spectral analysis of the arc in order to determine arc temperature and analytical modeling of the arc and weld puddle. The investigations have been directed toward determining the cause and effects of variations in the energy distribution incident upon the weldment. In addition, the effect of weld puddle distortion on weld penetration was investigated, and experimental and analytical studies of weld process variables have been undertaken to determine the effects of the variables upon weld penetration and configuration. A review of the results and analysis of these studies are presented

  19. Medical robotics

    CERN Document Server

    Troccaz, Jocelyne

    2013-01-01

    In this book, we present medical robotics, its evolution over the last 30 years in terms of architecture, design and control, and the main scientific and clinical contributions to the field. For more than two decades, robots have been part of hospitals and have progressively become a common tool for the clinician. Because this domain has now reached a certain level of maturity it seems important and useful to provide a state of the scientific, technological and clinical achievements and still open issues. This book describes the short history of the domain, its specificity and constraints, and

  20. Service Robots

    DEFF Research Database (Denmark)

    Clemmensen, Torkil; Nielsen, Jeppe Agger; Andersen, Kim Normann

    The position presented in this paper is that in order to understand how service robots shape, and are being shaped by, the physical and social contexts in which they are used, we need to consider both work/organizational analysis and interaction design. We illustrate this with qualitative data...... and personal experiences to generate discussion about how to link these two traditions. This paper presents selected results from a case study that investigated the implementation and use of robot vacuum cleaners in Danish eldercare. The study demonstrates interpretive flexibility with variation...