Stability and transparency in bilateral teleoperation
01 Oct 1993-Vol. 9, Iss: 5, pp 624-637
TL;DR: It is shown that a proper use of an four channels is of critical importance in achieving high performance telepresence in the sense of accurate transmission of task impedances to the operator.
Abstract: Tools for quantifying teleoperation system performance and stability when communication delays are present are provided A general multivariable system architecture is utilized which includes all four-types of data transmission between master and slave: force and velocity in both directions It is shown that a proper use of an four channels is of critical importance in achieving high performance telepresence in the sense of accurate transmission of task impedances to the operator It is also shown that transparency and robust stability (passivity) are conflicting design goals in teleoperation systems The analysis is illustrated by comparing transparency and stability in two common architectures, as well as a recent passivated approach and a new transparency-optimized architecture, using simplified one-degree-of-freedom examples >
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TL;DR: This survey addresses the subject of bilateral teleoperation, a research stream with more than 50 years of history and one that continues to be a fertile ground for theoretical exploration and many applications.
1,584 citations
01 Jan 1976
660 citations
TL;DR: The proposed control framework provides humans with extended physiological proprioception, so that s/he can affect and sense the remote slave environments mainly relying on her/his musculoskeletal systems.
Abstract: We propose a novel control framework for bilateral teleoperation of a pair of multi-degree-of-freedom nonlinear robotic systems under constant communication delays. The proposed framework uses the simple proportional-derivative control, i.e., the master and slave robots are directly connected via spring and damper over the delayed communication channels. Using the controller passivity concept, the Lyapunov-Krasovskii technique, and Parseval's identity, we can passify the combination of the delayed communication and control blocks altogether robustly, as long as the delays are finite constants and an upper bound for the round-trip delay is known. Having explicit position feedback through the delayed P-action, the proposed framework enforces master-slave position coordination, which is often compromised in the conventional scattering-based teleoperation. The proposed control framework provides humans with extended physiological proprioception, so that s/he can affect and sense the remote slave environments mainly relying on her/his musculoskeletal systems. Simulation and experiments are performed to validate and highlight properties of the proposed control framework
551 citations
Cites background from "Stability and transparency in bilat..."
...While the scattering-based teleoperation can be used without any knowledge of the (finite, constant) delays, our proposed framework requires knowing an upper bound of the round-trip delay....
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...In [4], this scattering-based result is further extended, and the notion of the wave variables was introduced....
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TL;DR: This design methodology aims to create a virtual tool which accounts for the implicit limitations imposed by the delay, and uses wave variables for the analysis and implementation, and builds a system with consistent and predictable behavior.
Abstract: In this paper we survey the development of the wave variable concept and examine wave-based teleoperation. We study the behavior of force reflecting systems under unknown but constant transmission delays, ranging from periods less than the human reaction time to several seconds. Passive transmission procedures guarantee system stability, but wave reflections and spurious dynamics may interfere with normal operation. Using wave variables for the analysis and implementation, and making appropriate design choices, a system with consistent and predictable behavior is constructed. This design methodology aims to create a virtual tool which accounts for the implicit limitations imposed by the delay. These developments also form the basis for extensions to wave-based prediction and application to variable delays, such as those inherent to Internet-based telemanipulation.
547 citations
Cites background or methods from "Stability and transparency in bilat..."
...In particular, Lawrence (1993) uses impedance models to describe the stability and transparency of various teleoperation schemes accounting for transmission delays....
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...The dual objectives of stability and transparency have led to numerous controller architectures that transmit different combinations of position and force signals (Lawrence 1993)....
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25 Mar 2004
TL;DR: Using defined evaluation indices, bilateral controller is designed and it is confirmed that the three desired conditions in bilateral teleoperation are well satisfied with this controller.
Abstract: There are many works about bilateral teleoperation. However, good touch sense of remote object has not been realized in actual system yet. In this paper, the goals of bilateral teleoperation are considered as following two points. One is a reproduction of environmental impedance in master side. The other is a realization of small operational force. Operational force means the force the operator feels in addition to real environmental force. Corresponding to these goals, novel evaluation indices are defined which are named "reproducibility" and "operationality", respectively. Moreover, control stability must be satisfied. After all, bilateral teleoperation must satisfy three conditions such as reproducibility, operationality and stability. Using defined evaluation indices, bilateral controller is designed. Through analysis, it is confirmed that the three desired conditions in bilateral teleoperation are well satisfied with this controller. The effectiveness of this research is demonstrated by an experiment with bilateral forceps robot.
434 citations
References
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Book•
01 Jan 1975
TL;DR: In this paper, the Bellman-Gronwall Lemma has been applied to the small gain theorem in the context of linear systems and convolutional neural networks, and it has been shown that it can be applied to linear systems.
Abstract: Preface to the Classics edition Preface Acknowledgments Note to the reader List of symbols 1. Memoryless nonlinearities 2. Norms 3. General theorems 4. Linear systems 5. Applications of the small gain theorem 6. Passivity Appendix A. Integrals and series Appendix B. Fourier transforms Appendix C. Convolution Appendix D. Algebras Appendix E. Bellman-Gronwall Lemma References Index.
2,894 citations
TL;DR: In this paper, a control law for teleoperators is presented which overcomes the instability caused by time delay by using passivity and scattering theory, a criterion is developed which shows why existing bilateral control systems are unstable for certain environments, and why the proposed bilateral control law is stable for any environment and any time delay.
Abstract: A control law for teleoperators is presented which overcomes the instability caused by time delay. By using passivity and scattering theory, a criterion is developed which shows why existing bilateral control systems are unstable for certain environments, and why the proposed bilateral control law is stable for any environment and any time delay. The control law has been implemented on a single-axis force-reflecting hand controller, and preliminary results are shown. To keep the presentation clear, a single-degree-of-freedom (DOF) linear time-invariant (LTI) teleoperator system is discussed. Nevertheless, results can be extended, without loss of generality, to an n-DOF nonlinear teleoperation system. >
2,131 citations
TL;DR: In this article, a physically motivated, passivity-based formalism is used to provide energy conservation and stability guarantees in the presence of transmission delays, and an adaptive tracking controller is incorporated for the control of the remote robotic system and can be used to simplify, transform or enhance the remote dynamics perceived by the operator.
Abstract: A study is made of how the existence of transmission time delays affects the application of advanced robot control schemes to effective force-reflecting telerobotic systems. This application best exploits the presence of the human operator while making full use of available robot control technology and computing power. A physically motivated, passivity-based formalism is used to provide energy conservation and stability guarantees in the presence of transmission delays. The notion of wave variable is utilized to characterize time-delay systems and leads to a configuration for force-reflecting teleoperation. The effectiveness of the approach is demonstrated experimentally. Within the same framework, an adaptive tracking controller is incorporated for the control of the remote robotic system and can be used to simplify, transform, or enhance the remote dynamics perceived by the operator. >
1,286 citations
01 Aug 1989
TL;DR: It is shown that the hybrid model (as opposed to other two-port forms) leads to an intuitive representation of ideal teleoperator performance and applies to several teleoperator architectures.
Abstract: The application of a hybrid two-port model to teleoperators with force and velocity sensing at the master and slave is presented. The interfaces between human operator and master, and between environment and slave, are ports through which the teleoperator is designed to exchange energy between the operator and the environment. By computing or measuring the input-output properties of this two-port network, the hybrid two-port model of an actual or simulated teleoperator system can be obtained. It is shown that the hybrid model (as opposed to other two-port forms) leads to an intuitive representation of ideal teleoperator performance and applies to several teleoperator architectures. Thus measured values of the h matrix or values computed from a simulation can be used to compare performance with the ideal. The frequency-dependent h matrix is computed from a detailed SPICE model of an actual system, and the method is applied to a proposed architecture. >
966 citations
23 May 1990
TL;DR: In this article, a preliminary study of what role recent results in adaptive robot control and the understanding of time-delays may play in the development of effective telerobotics systems, which would best exploit the presence of the human operator while making full use of available robot control technology and computing power.
Abstract: Telerobotics, the body of science and technology which bridges human control and purely autonomous machines, is expected to be a merging point of modern developments in robotics, control theory, cognitive science, machine design, and computer science. Besides traditional applications in space, subsea, and handling of hazardous material, many new potential uses of advanced telerobotic systems have recently been suggested or explored, such as safety applications or microsurgery. This paper is a preliminary study of what role recent results in adaptive robot control and the understanding of time-delays may play in the development of effective telerobotics systems, which would best exploit the presence of the human operator while making full use of available robot control technology and computing power. The key paradigm it explores is that of simplifying, transforming, or enhancing the remote dynamics perceived by the operator by proper use of adaptive robot control techniques and tools from passivity theory.
936 citations