Master Arm Research Articles

Motion and Force Control of Flexible Master-Slave System (Improvement of State Estimation During Contacting with Objects)

We study the motion, vibration and contact force control of the flexible master-slave system (FMSS). In this study, the master arm is a one-link arm that consists of a rigid body and the slave arm is a one-link arm that consists of a flexible link. The bilateral control based on passivity and the optimal control based on the linear quadratic regulator (LQR) are applied to the system. Each of those control methods has some advantages and disadvantages. We employ the state observer to construct those controllers. However, the accuracy of state estimation is deteriorated while the slave-arm contacts with objects. Therefore we improve the accuracy of the state estimation by applying the disturbance-state observer. We indicate the performance of the present method by experimental results.

Cooperation of Humanoid Robots Using Teleoperation for Transferring an Object

In this paper, a method is proposed for humanoid robots performing object transfering task in a teleoperated cooperative paradigm. The cooperative task is accomplished using simple communication among two humanoid robots and then switch between modes according to the situation. In case of object passing with two humanoid robots, mutual position shifts may occur while they are moving. Therefore, it is necessary to correct the position in a real-time manner. To control the arm and hand of the robot remotely we use master arm and hand while it carries and passes the object, the dynamic stability during the execution of walking is ensured by incorporating the ZMP criterion and the desired spacing between the robots is controlled by Leader follower type control. Object passing cooperation for two humanoid robots is based on computer control, wireless LAN, vision, cooperative handling control and text commands. The method is applied as key software of the system. The effectiveness of the proposed methodology for performing cooperatively real time tasks is discussed.

A unifying framework for robot control with redundant DOFs

Recently, Udwadia (Proc. R. Soc. Lond. A 2003:1783–1800, 2003) suggested to derive tracking controllers for mechanical systems with redundant degrees-of-freedom (DOFs) using a generalization of Gauss’ principle of least constraint. This method allows reformulating control problems as a special class of optimal controllers. In this paper, we take this line of reasoning one step further and demonstrate that several well-known and also novel nonlinear robot control laws can be derived from this generic methodology. We show experimental verifications on a Sarcos Master Arm robot for some of the derived controllers. The suggested approach offers a promising unification and simplification of nonlinear control law design for robots obeying rigid body dynamics equations, both with or without external constraints, with over-actuation or underactuation, as well as open-chain and closed-chain kinematics.

Exoskeleton arm with force feedback for robot bilateral teleoperation

Abstract A novel 6 degrees of freedom (DOFs) wearable exoskeleton arm, ZJUESA, based on man-machine system is presented. It can be used in robot bilateral teleoperation as master arm with force-feedback. With introducing the revolute-prismatic-spherical (RPS) parallel mechanism and planetary gear mechanism, it is designed based on the anatomy of human upper-limb. With the sensors on this external mechanical structure, the human operator motion is detected and converted to the slave robot control command. Additionally the pneumatic system on it generates a force feedback by using hybrid fuzzy control. As a result, the human operator may have a feeling of doing the work directly. *Supported by National Natural Science Foundation of China (Grant No. 50305035)

242 フレキシブル・マスター : スレーブシステムの運動と力の制御

We study the motion, vibration and contact force control of the flexible master-slave system (FMSS). In this study, the master arm is a one-link arm that consists of a rigid body and the slave arm is a one-link arm that consists of a flexible link. The bilateral control based on passivity and the optimal control based on the linear quadratic regulator (LQR) are applied to the system. Each of those control methods has some advantages and disadvantages. We employ the state observer to construct those controllers. However, the accuracy of state estimation is deteriorated while the slave-arm contacts with objects. Therefore we improve the accuracy of the state estimation by applying the disturbance-state observer. We indicate the performance of the present method by experimental results.

마스트 암 엔드-이펙터 궤적에 관한 연구

생활수준이 향상 될수록 로봇이 인간의 노동을 대신하는 요소는 더욱 많아지고 있다. 하지만 대부분의 로봇이 지면에 고정된 장치산업에 국한되어 있기 때문에, 폭넓은 응용가치가 기대되는 휴먼 로봇에 대한 필요성이 강조되고 있다. 휴먼로봇은 사람을 대신하기 위한 목적으로 많은 연구가 진행되고 있지만, 관련 하드웨어의 부족으로 매우 단순하고 제한적으로 적용되고 있다. 이러한 한계를 극복하기 위해 본 연구에서는 기구학적인 메커니즘과 제어장치를 개발하여, 어깨와 팔을 3자유도 형태로 마스트 암을 구성하고, 관절변수의 특성과 엔드-이펙터 궤적실험을 통하여 사람과 유사한 동작을 재현하였다.

On a Posture Control of Human Robot Master Arm

This study developed a human robot mast arm, which has a structure similar to the human arm, with the objective of taking over human works. The robot arm was structured to reproduce human actions using three axes on each of the shoulder and the wrist based on mechanics, and the actuator of each axis adopted an ordinary DC motor. The servo?system of the actuator is a one?body type employing an amp for electric power, and it was designed to be small and lightweight for easy installation. We examined the posture control characteristics of the developed robot mast arm in order to test its interlocking, continuous motions and reliability.

Force‐feedback teleoperation of an industrial robot in a nuclear spent fuel reprocessing plant

PurposeAims to describe how to make an industrial robot work as a telemanipulator with force feedback, in order to carry out various tasks for remote handling in nuclear fuel cycle plants.Design/methodology/approachThe robot Staübli RX170 (used as a slave arm) has been fitted with a force‐torque sensor and an electronic system for sensors' signals multiplexing. The overall system has been made tolerant to γ radiation up to a 10 kGy integrated dose. The industrial robot has been coupled to a master arm with force feedback capability and to the computer assisted teleoperation controller TAO2000 developed by CEA‐LIST.FindingsThe result of the maintenance operation reported in the paper, carried out with a Staübli RX170 robot at AREVA/COGEMA La Hague plant, illustrates the validity of this approach and demonstrates how remote handling can benefit from this new technology.Originality/valueIntroduces the teleoperation of industrial robots as a new solution for the maintenance of nuclear facilities. Wrist force/torque sensing and advanced master‐slave controller provide the operators with a high performance teleoperation system. Only limited modification of the existing design of the industrial robot has been carried out in order to transform it into a nuclear telemanipulator.

Development of Anthropomorphic Multi-D.O.F. Master-Slave Arm for Mutual Telexistence

We developed a robotic arm for a master-slave system to support "mutual telexistence," which realizes remote dexterous manipulation tasks and close physical communication with other people using gestures. In this paper, we describe the specifications of the experimental setup of the master-slave arm to demonstrate the feasibility of the mutual telexistence concept. We developed the master arm of a telexistence robot for interpersonal communication. The last degree of the 7-degree-of-freedom slave arm is resolved by placing a small orientation sensor on the operators arm. This master arm is made light and impedance control is applied in order to grant the operator as much freedom of movement as possible. For this development stage, we compared three control methods and confirmed that the impedance control method is the most appropriate to this system.

力覚提示機能を有するＷＷＷ上に構築された仮想環境操作システム

A virtual model-manipulation system-aimed at off-line teleoperation teaching-has been developed on the World Wide Web. To give a feeling to the virtual model manipulation, the system is equipped with a force-display function as well as a virtual display. To realize this feeling, a high-speed contact-motion simulator enables the computation of constrained motion in the virtual environment. In addition, a firm force reaction is produced by using a sixdegrees-of-freedom position-controlled manipulator with force feedback as a master arm. This manipulation system is intended to be used by anybody, anywhere, at any time freely. It uses standard modules (such as Web browsers for GUIs, VRML for graphics, and Java applet) and a position-controlled manipulator for model handling. Consequently, the developed system can be utilized anytime from anywhere equipped with the master arm. A prototype system was developed and virtual model manipulation was carried out successfully in two environment: a simple block world and a complex room environment. The manipulation system was experimentally tested, and it was shown that the new system can effectively manipulate a virual model.

MASTER-SLAVE SYSTEM WITH TELEOPERATION FOR REHABILITATION

In this paper, a master-slave robot system with haptic feedback, human sensing and teleoperation for rehabilitation of upper limb function is presented. The physician could adjust on-line the exercise based on the EMG signal of the patient and force feedback. Moreover, in the present teleoperating system, it is shown that the stability is guaranteed due to the passivity of the master arm's mechanism, in spite of the communication time delay.

Remote Operation of the Radiation-Proof Robot Using the Direct Master Arm System

In Japan Atomic Energy Research Institute, we have developed a radiation-proof robot (called Ra BOT) for accomplishing a given mission under severe conditions such as gamma radiation. RaBOT can be maneuvered by remote commands from the operation desk with the master arm system. However, the system has become large and complicated because the master arms have the same number of active joints as the slave manipulators; moreover, that provide not only the required sensory feedbacks on the operator but also uncomfortable constraints. This report examines the performance of teleoperation for the master arm system and proposes a new type of master arm as the alternative.

Teleoperation with a Distributed Multiagent-Based Slave Manipulator Control System

Teleoperation is one of the oldest and presents useful applications in robotics. A teleoperator system consists of a master arm, a slave arm and an operator. Traditionally, slave arm control is achieved by analytical solutions. Multiagent-based paradigm is emerging in Artificial Intelligence. A slave arm can be thought of a group of separately controlled agents that a multiagent-based paradigm can be applied. In this paper, we investigate viability of a multiagentbased slave manipulator control with a cable-driven teleoperator system.

RTコンポーネントによるマスタアーム制御システム構築 : RTミドルウェアの基本機能に関する研究開発(その6)(オープン化を指向したロボットコントローラアーキテクチャ1)

RTコンポーネントによるマスタアーム制御システム構築 : RTミドルウェアの基本機能に関する研究開発(その6)(オープン化を指向したロボットコントローラアーキテクチャ1)

Transmission and Reproduction of Force Sensation by Bilateral Control

Minimally invasive surgery (MIS) which thinks a great deal of patient’s quality of life (QOL) has attracted attention during about ten years. In this paper, it aims at development of the technology for transmitting force sensation required in medical treatment especially through surgical instruments, such as forceps. In bilateral control, it is a problem how master and slave robots realize the law of action and reaction to the environment. Mechanism of contact with environment and bilateral controller based on stiffness are shown. Master arm in contact with human and slave arm in contact with environment are given compliance, and stable contact with environment can be realized. The proposed method is applied to 3-link master-slave manipulators. As a result, transmission and reproduction of force sensation can be realized. The experimental results show viability of the proposed method.

機能的電気刺激により反力提示する新しいバイラテラル遠隔制御システムの開発

In teleoperation of manipulators, the positions and velocities of the slave actuators should resemble those of the master controls to help the operator project his presence into the slave space. Direct viewing by TV has been in-corporated into teleoperator design based on this philosophy, and then becomes a most common sensor subsystem of teleoperator. Force reflection to the operator is also recognized as a useful sensory correspondence for enhancing the operator's identification with the task at hand. Several exoskeletal devices have been proposed as the master arms for the force reflection. However, the mechanisms become complicated because the arms should have the same number of active joints as the slave manipulators; moreover, those provide not only the required sensory feedbacks on the operator but also uncomfortable constraints. So as to overcome this difficulty, we propose a new man-machine interface in which functional electrical stimulation is used to present the reaction forces to the operator. Three small electrodes and two small position/orientation sensors are attached on the skin of the upper limb of the operator. Force reflection from the slave manipulator to the operator is achieved by functional electrical stimulation through the surface electrodes. There is no mechanical element in our master subsystem because the upper limb of the operator works as the master arm by itself. It is shown in this paper that the proposed structure of master subsystem allows the operator to be released from the unnecessary constraints of exoskeletal devices. The effectiveness of the proposed teleoperator is illustrated by several experiments with a seven axis slave manipulator.

バイラテラル制御による非接触マイクロマニピュレーション レーザマイクロマニピュレータによるマイクロツール制御

A laser micromanipulator is suitable for non-contact manipulation of a small object, such as a bacteria and microbe, in the closed space. However, laser trapping has two serious problems to control a living microbe. One is the damage caused by direct irradiation of high power laser to the target, and the other is the weakness of the trapping force, which causes swerving of the target from the desired transportation trajectory by disturbances. For safe and secure transportation of the microbe, we proposed to transport a microbe with micro tools trapped by the laser. Here we developed a measurement system of the laser trapping force using a quadrant photo detector (QPD) . We analyzed the measurement area of the QPD and calibrated the trap stiffness. Then we applied the bilateral control to the laser micromanipulation of the micro tool. The operator can feel the magnified force of the laser micromanip-ulation through the master arm. Finally, we demonstrated the indirect micromanipulation of the Yeast using laser manipulated micro tool.

9C31 ダイレクトマスタアームシステムの福祉への応用

9C31 ダイレクトマスタアームシステムの福祉への応用

Operator Performance in Surgical Telemanipulation

The application of telemanipulator systems in minimally invasive surgery (MIS) poses high demands on the quality of force feedback. Forces exerted on the tissue are often small and should be reflected back amplified to the surgeon. The dynamic behavior of a telemanipulator system can be adjusted in three basic ways to guarantee sufficient stability robustness in spite of high force scaling factors: by scaling down the surgeon's input motion, by increasing the compliance at the slave arm, and/or by increasing the motion resistance at the master arm. More “transparent” telemanipulator dynamics can be achieved when the damping provided by the surgeon's hand-arm-system is taken into account (for example, the motion resistance necessary to guarantee stability robustness can be reduced). This paper investigates the effect of the three basic types of telemanipulator dynamics on operator performance in surgical tasks. The impact of improving transparency by making use of operator damping is also studied. Three experiments imitating elementary surgical procedures were conducted: inserting a catheter tip into a vessel, puncturing a membrane, and detecting differences in tissue hardness through palpation. Subjects exerted significantly higher forces when inserting a catheter without force feedback, which shows the benefit of force feedback in surgical telemanipulation. Performance of the subjects was also greatly influenced by the basic type of telemanipulator dynamics. However, differences in outcome between the experiments indicate that the best basic type will generally depend on the surgical task at hand. Improving the transparency of the telemanipulator system by making use of operator damping did not improve performance of the subjects any further. Thus, it appears that providing the appropriate basic type of telemanipulator dynamics for a given task may be even more critical to the performance of the surgeon than an optimized transparency of the telemanipulator dynamics.

An Experimental Teleoperation System for Dual-Arm Space Robotics

An experimental teleoperation system for dual-arm space robotics has been developed. A purpose of our work using this system is a development of space robot teleoperation technologies, which can replace skills of an astronaut. Therefore, several concepts for flexibility and practicability are introduced to establish this setup. This system is composed of the space system, the ground system and the software development system. The space system includes dual 7-DOF manipulators, multipurpose hands, force/torque sensors and an image processing system. The ground system is composed of a master arm and a graphic workstation. A novel developed 6-DOF haptic interface device is employed as a master arm. To achieve an effective teleoperation ability, new concepts of virtual grip and virtual ball are introduced.