Department Publications

Effective training is essential for human teleoperators to deliver satisfactory performance in actual tasks. Teleoperation is naturally a very difficult task due to the absence of naked-eye vision that cripples the cognitive behavior of the remote operator. Camera vision somehow is not a satisfactory substitution. However, training with naked-eye vision feedback may help human teleoperators to learn how to deliver satisfactory performance when they actually interact with camera vision. This study was carried out to further investigate this hypothesis, and to quantitatively supplement it with experimental proofs. For this cause, the recently built telerobotic test-bed between KAIST (Korea) and Saga University(Japan) was reshaped to a telerobotic mini-golf system, which is the trial experiment in this study. The performance of the players with and without naked-eye training was compared and quantitatively evaluated. The …

This paper discusses the safety assurance, capability features, and user-friendliness of Internet-based telerobotics, in the sense that how these features could be incorporated in order to enhance teleoperator performance. A comprehensive set of safety features are incorporated to the interface to screen and accept only the safe commands from the remote operator while discarding risky commands. A laser pointer is used to help remote operator in perceiving self-location and navigation, whereas orientation control has been completely automated and synchronized to the position commands of the teleoperator. The effectiveness of these features has been demonstrated by playing telerobotic mini-golf.

This paper describes the design and implementation techniques of a generic Internet-based telerobotic system. The purpose is to make available the precious technical information and hands-on experience of the authors for the research community. The paper is based on the telerobotics system that the authors recently implemented between KAIST, Korea and Saga University, Japan. In its current functionality, two control modes: high-level supervisory control and low-level supervisory control are explored demonstrating their merits and demerits.

A telerobotic test-bed has recently been built between KAIST (Korea) and Saga University (Japan). This paper presents its first research work on investigating the interactive learning performance of human teleoperators. For this purpose, the telerobotic test-bed was re-shaped to a telerobotic golf system. Eleven players were participated, and their interactive performance with the telerobot was carefully analyzed for the errors and skills that they demonstrated. It was observed that human teleoperators first try to avoid errors that they did in the previous trials, and then make efforts to explore new skills. It was also experienced that simple task oriented design features and their coordination could significantly improve telerobotic system performance without making it to an excessively sophisticated shape. Interactive learning with naked-eye vision was compared with that of camera vision, and an effective training procedure for human teleoperators was revealed. Some simple, yet appropriate techniques have also been identified that significantly enhance the performance of human teleoperators.

This paper presents an effective trajectory planning algorithm for industrial robot manipulators. Given the end-effector trajectory in Cartesian space, together with the relevant constraints and task specifications, the proposed method is capable of planning the optimum endeffector trajectory. The proposed trajectory planning algorithm considers the joint acceleration limit, end-effector velocity limits, and trajectory allowance. A feedforward compensator is also incorporated in the proposed algorithm to counteract the delay in joint dynamics. The algorithm is carefully designed so that it can be directly adopted with the existing industrial manipulators. The proposed algorithm can be easily programmed for various tasks given the specifications and constraints. A three-dimensional test trajectory was planned with the proposed algorithm and tested with the Performer MK3s industrial manipulator. The results verified effective manipulator performance within the constraints.

A new pole selection method for feedforward compensators of mechatronic servo systems is presented in this paper. It is necessary to have the system poles located at desirable positions on the s-plane in order to realize better servoing performance. However, selection of new poles is not a straightforward problem and in most industrial mechatronic systems, it has been a mere cut-and-dry procedure. In this research, feedforward compensator poles are related to the control input, and a criterion was developed to determine the desirable poles that improve the control input within its limits. This method was developed for the second-order model and it was simulated and experiments were performed with the Performer MK3s articulated industrial robot manipulator. Some attractive results have been obtained with the new method.

This paper describes the design and implementation techniques of a generic Internet based telerobotic system. The purpose is to make precious technical information and hands-on experience of the authors widely available for the research community. The paper is based on the telerobotics system that the authors recently implemented between KAIST and Saga University, Japan. In its current functionality, two control modes can be exercised; high-level supervisory control, and low-level supervisory control.

This thesis focuses on trajectory planning for industrial robot manipulators. It describes the existing problem of trajectory planning and proposes an appropriate solution. The proposed solution has been devised, implemented and verified for effective functionality. Trajectory planning in this context is the process of planning time-based joint position trajectories for a desired end-effector motion. It needs to consider all relevant constraints of the manipulator and given task specifications, because the final end-effector performance totally depends on the way the joint trajectories are planned. However, most trajectory planners in industrial robotics, even today, have adapted the technique of direct sampling of the desired end-effector motion, and transform such Cartesian positions to joint space using inverse kinematics. Then, the planned joint trajectories are simulated to check if they are realizable within the constraints. It is also inspected if the given task specifications are fulfilled sufficiently. Planned end-effector trajectory is iteratively adjusted by trial-and-error, until an optimum trajectory is obtained. This process has many demerits and it is therefore necessary to develop an appropriate trajectory planning algorithm which has provisions to consider constraints and task specifications in planning end-effector trajectories. It should also be generally applicable to industrial manipulators. Through constant collaboration with Yaskawa Robotics Inc., the major considerations of trajectory planning were identified as being: 1. trajectory allowance, 2. sharp corners, 3. joint acceleration limit, 4. assigned end-effector velocity, 5. jerk reduction, and 6. delay dynamics …

Abstract< BR> Ⅰ. INTRODUCTION< BR> Ⅱ. MOTION PLANNING AND CONTROL OF ROBOT< BR> Ⅲ. TELEOPERATION AND SUPERVISORY CONTROL< BR> Ⅳ. WELFARE TELEROBOTIC SYSTEM< BR> Ⅴ. RESULTS AND DISCUSSION< BR> Ⅵ. CONCLUSION< BR> ACKNOWLEDGEMENTS< BR> REFERENCES< BR> APPENDIX: BASIC STEPS OF MOTION PLANNING< BR>

Addresses the trajectory tracking problem of industrial robot manipulators, at the corners of a Cartesian three-dimensional trajectory. The goal is to determine the maximum tangential velocity of the end-effector as it traverses a circular arc at a trajectory corner while avoiding joint acceleration saturation. The proposed method first derives the relationship between end-effector velocity and joint accelerations, and then develops a criterion to determine maximum tangential velocity so that only one joint marginally reaches its acceleration limit at a single point on the circular arc. The method was successfully experimented with, and improved performance has been demonstrated.

This research proposes a supervisory control scheme for industrial telemanipulators. The final goal is to devise a control methodology for the effective teleoperation of industrial robot manipulators. Supervisory control is utilized as the base of the control methodology, in that the remote supervisor (human operator) communicates only the important task parameters to the local controller, over the Internet. Local controller plans the optimum trajectory considering supervisor instructions and local constraints, and finally controls the telemanipulator. Reference positions of the desired end-effector trajectory, assigned end-effector speed, working precision, and joint acceleration limits are the important task parameters communicated by the remote supervisor. Local controller considers such specifications in its trajectory planning algorithm. The proposed supervisory control scheme was successfully devised and experimented between the Department of Advanced Systems Control Engineering, Saga University (ASCESU) and Kurume National College of Technology (KNCT).

Presents a general solution to the contouring problem of industrial robot arms, under the constraints of assigned Cartesian velocity and joint torque/acceleration. The proposed solution is an off-line trajectory generation algorithm and, therefore, it possesses significant industrial implications, as no hardware changes are needed for its implementation. According to the proposed method, the maximum utility of joint torque/acceleration is guaranteed to be bound to the assigned velocity constraint. In the proposed method, a realizable trajectory is generated from the objective trajectory and its delay dynamics are compensated for by using a forward compensator. The proposed method has been experimented with using a Performer MK-3s (PMK-3s) industrial robot arm, and optimum contouring has been realized.

Presents a control algorithm for industrial robot arms. This algorithm is based on off-line trajectory generation with compensation of statics and dynamics. Using the proposed method, the Performer MK-3s industrial robot arm was controlled and improved performance has been realized. The proposed algorithm appears as a feedforward, off-line block in the robot arm control system. Therefore, it could be conveniently incorporated with the industrial robot arms without significant hardware alterations.

This paper addresses the contouring problem of articulated industrial robot arms, and proposes a practical solution to realize precise, jerk-free servoing. The proposed solution is an off-line trajectory construction algorithm that addresses the relevant industrial constraints and specifications namely, the velocity constraint, torque/acceleration constraint and trajectory allowance. Spline approximation is used to eliminate jerking. A forward compensator is used to compensate for delay dynamics. The proposed method was implemented experimentally on a Performer Mk-3s industrial robot arm, and improved performances were demonstrated.

Pole selection for modified taught data method for mechatronic servo systems by considering bounded control | CiNii Research CiNii 国立情報学研究所 学術情報ナビゲータ[サイニィ] 詳細へ 移動 検索フォームへ移動 論文・データをさがす 大学図書館の本をさがす English 検索 タイトル 人物 /団体名 著者ID/研究者番号 所属機関 ISSN DOI 期間 ~ 本文リンク 本文リンクあり データソース JaLC IRDB Crossref DataCite NDLサーチ NDLデジコレ(旧NII-ELS) RUDA JDCat NINJAL CiNii Articles CiNii Books NACSIS-CAT/ILL DBpedia KAKEN Integbio PubMed LSDB Archive 極地研ADS 極地研学術DB OpenAIRE 公共データカタログ すべて 研究データ 論文 本 博士論文 プロジェクト 人物 > 人物検索機能について Pole selection for modified taught data method for mechatronic servo systems by considering bounded control 被引用文献1件 MUNASINGHE SR 収録刊行物 Proc. SICE Kyushu Branch Annual Conf, Kagoshima, Japan, 2001 Proc. SICE …

Contour control of a robot arm is an act of the end-effector tip being moved along a reference Cartesian path, with an assigned velocity. When torque saturation occurs, and lasts for some time, contour deteriorations result. In addition, system delay dynamics also causes contour deteriorations. In this paper, an offline trajectory generation algorithm is described, which achieves both optimum avoidance of torque saturation and delay dynamics compensation.

Feasible Method of Optimum Control of Industrial Robot Arms in Operation Under Speed and Torque Constraints | CiNii Research CiNii 国立情報学研究所 学術情報ナビゲータ[サイニィ ] 詳細へ移動 検索フォームへ移動 論文・データをさがす 大学図書館の本をさがす English 検索 タイトル 人物/団体名 所属機関 ISSN DOI 期間 ~ 本文リンク 本文リンクあり データソース JaLC IRDB Crossref DataCite NDLサーチ NDLデジコレ(旧NII-ELS) RUDA JDCat NINJAL CiNii Articles CiNii Books NACSIS-CAT/ILL DBpedia KAKEN Integbio PubMed LSDB Archive 極地 研ADS 極地研学術DB OpenAIRE 公共データカタログ すべて 研究データ 論文 本 博士論文 プロジェクト Feasible Method of Optimum Control of Industrial Robot Arms in Operation Under Speed and Torque Constraints 被引用文献1件 NAKAMURA M. 収録刊行物 3rd Asian Control Conference 3rd Asian Control Conference 2000 …

This paper presents a methodology for off-line trajectory generation that guarantees high-speed and precise end-effector point-to-point (positioning) control of industrial robot arms, within the bounds of the most relevant constraints. The constraints being addressed are the saturation of joint torque and the limit of Cartesian velocity. In the proposed methodology, shortest path of travel and maximum-joint torque/acceleration utility is guaranteed so that the true minimum-time trajectory is generated. The minimum-time trajectory is then compensated for the delay dynamics using a feedforward compensator. An illustrative implementation is presented using the Performer MK-3s robot arm, with which attractive results have been obtained. Being an off-line algorithm, the proposed method can be conveniently introduced into existing servo control systems of industrial robot arms, and to enhance their performance.

Contour control of a robot arm is an act of the end-eflector being moved along a reference Cartesian path, with an assigned uelocity. While contouring sharp corners and, at the start and the end of the operation, a substantial torque demand is originated from the refer-ence input generator. It causes power amplifier saturation of the servo controller and hence the saturation of joint torque. Once torque saturation occurs, and last for some time, contour deteriorations are resulted. In addition, system delay dynamics also causes contour deteriorations. In this research, optimum avoidance of torque saturation and delay dynamics compensation are achieved by an off-line trajectory generation algorithm and modified taught data algorithm.

Manipulators with multi degree of freedom for accomplishing various complex manipulation in the work space

Telerobotics is the teleoperation of robotic devices from a distance and deployment of telerobots in such environments, where it is not economical or safe to have human workers. The challenges for teleoperation of robots are many; time delay, limited perception of the work-site, lack of robot’s intelligence, to name a few. This paper describes how telerobotic systems are designed, their problems, and techniques to overcome them. This paper also describes the Internet-based mini-golf telerobotic system between Korea and Japan.

(PDF) Trajectory Planning for Industrial Robot Manipulators Academia.edu Academia.edu Log In Sign Up Log In Sign Up more About Press Papers Terms Privacy Copyright We're Hiring! Help Center less Outline keyboard_arrow_down Title Abstract First page of “Trajectory Planning for Industrial Robot Manipulators” PDF Icon download Download Free PDF Download Free PDF Trajectory Planning for Industrial Robot Manipulators Profile image of Prof. Rohan Munasinghe Prof. Rohan Munasinghe visibility … description 8 pages descriptionSee full PDF downloadDownload PDF bookmarkSave to Library shareShare close Sign up for access to the world's latest research Sign up for freearrow_forward checkGet notified about relevant papers checkSave papers to use in your research checkJoin the discussion with peers checkTrack your impact Abstract sparkles AI This paper presents a trajectory planning framework …

An strategic design for Internet-based telerobotic systems is presented. Aspects of safety, stability, capability, accuracy, as well as operator interactivity are considered. A comprehensive set of safety features are built-in to the remote operator interface in order to accept only the safe commands. A laser-guided end-effector helps remote operator accurately judge the geometry of the telerobot’s worksite. Task resolved motion control is used to automatically control as many number of degrees-of-freedoms as possible so that the workload on the remote operator is reduced while improving system capability. Stability has been guaranteed by introducing supervisory control. Length of operator position commands is adjusted as update rate of the visual display changes due to uncertain traffic on the Internet, which helps the remote operator to maintain a frequent interaction with the telerobot, and perform predictive control …