scholarly journals Stabilization of Teleoperation Systems with Communication Delays: An IMC Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yuling Li
Keyword(s):  
Time Delays ◽  
Closed Loop ◽  
Internal Model Control ◽  
Bilateral Teleoperation ◽  
Closed Loop System ◽  
Teleoperation System ◽  
Model Control ◽  
The Stability ◽  
External Forces ◽  
Teleoperation Systems

The presence of time delays in communication introduces a limitation to the stability of bilateral teleoperation systems. This paper considers internal model control (IMC) design of linear teleoperation system with time delays, and the stability of the closed-loop system is analyzed. It is shown that the stability is guaranteed delay-independently. The passivity assumption for external forces is removed for the proposed design of teleoperation systems. The behavior of the resulting teleoperation system is illustrated by simulations.

A Simple Structure for Bilateral Transparent Teleoperation Systems With Time Delay

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Alireza Alfi ◽  
Mohammad Farrokhi
Keyword(s):  
Time Delay ◽  
Closed Loop ◽  
Simple Structure ◽  
Finite Impulse Response ◽  
Structure Design ◽  
Loop System ◽  
Bilateral Teleoperation ◽  
Closed Loop System ◽  
The Stability ◽  
Teleoperation Systems

This paper presents a simple structure design for bilateral teleoperation systems with uncertainties in time delay in communication channel. The goal is to achieve complete transparency and robust stability for the closed-loop system. For transparency, two local controllers are designed for the bilateral teleoperation systems. One local controller is responsible for tracking the master commands, and the other one is in charge of force tracking as well as guaranteeing the stability of the closed-loop system in the presence of uncertainties in time delay. The stability analysis will be shown analytically for two cases: (I) the possibly stability and (II) the intrinsically stability. Moreover, in Case II, in order to generate the proper inputs for the master controller in the presence of uncertainties in time delay, an adaptive finite impulse response (FIR) filter is designed to estimate the time delay. The advantages of the proposed method are threefold: (1) stability of the closed-loop system is guaranteed under some mild conditions, (2) the whole system is transparent, and (3) design of the local controllers is simple. Simulation results show good performance of the proposed method.

Transparency Improvement by External Force Estimation in a Time-Delayed Nonlinear Bilateral Teleoperation System

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
H. Amini ◽  
S. M. Rezaei ◽  
Ahmed A. D. Sarhan ◽  
J. Akbari ◽  
N. A. Mardi
Keyword(s):  
Control Algorithm ◽  
Force Measurement ◽  
Bilateral Teleoperation ◽  
Force Estimation ◽  
Teleoperation System ◽  
Control Scheme ◽  
Environmental Force ◽  
The Stability ◽  
External Forces ◽  
Teleoperation Systems

Teleoperation systems have been developed in order to manipulate objects in environments where the presence of humans is impossible, dangerous or less effective. One of the most attractive applications is micro telemanipulation with micropositioning actuators. Due to the sensitivity of this operation, task performance should be accurately considered. The presence of force signals in the control scheme could effectively improve transparency. However, the main restriction is force measurement in micromanipulation scales. A new modified strategy for estimating the external forces acting on the master and slave robots is the major contribution of this paper. The main advantage of this strategy is that the necessity for force sensors is eliminated, leading to lower cost and further applicability. A novel control algorithm with estimated force signals is proposed for a general nonlinear macro–micro bilateral teleoperation system with time delay. The stability condition in the macro–micro teleoperation system with the new control algorithm is verified by means of Lyapunov stability analysis. The designed control algorithm guarantees stability of the macro–micro teleoperation system in the presence of an estimated operator and environmental force. Experimental results confirm the efficiency of the novel control algorithm in position tracking and force reflection.

Bilateral Parallel Force/Position Teleoperation Control

1999 ◽  
Author(s):  
Keyvan Hashtrudi-Zaad ◽  
Septimiu E. Salcudean
Keyword(s):  
Closed Loop ◽  
Position Control ◽  
Position Tracking ◽  
Task Space ◽  
Closed Loop System ◽  
Teleoperation System ◽  
And Performance ◽  
The Stability ◽  
Teleoperation Systems ◽  
Decoupled Systems

Abstract The application of parallel force/position control to teleoperation systems is considered in this paper. Higher priority is given to position control at the master side and to force control at the slave side of the teleoperation system. The stability and performance of the proposed controller is investigated by analyzing the three decoupled systems obtained from projecting the closed-loop system dynamics onto the slave task-space orthogonal directions. Experimental results demonstrate the excellent force and position tracking performance provided by the new controller.

Design of a New Impedance Controller for a Time Delay Teleoperation System

2013 ◽  
Vol 392 ◽  
pp. 355-360
Author(s):  
Young Won Chang ◽  
Olga Kostiyukova ◽  
Kil To Chong
Keyword(s):  
Time Delays ◽  
Position Control ◽  
Control Architecture ◽  
Time Varying ◽  
Bilateral Teleoperation ◽  
Bilateral Control ◽  
Single Degree Of Freedom ◽  
Teleoperation System ◽  
The Stability ◽  
Teleoperation Systems

Bilateral teleoperation systems connected to computer networks such as the internet have to deal with varying time delays depending on several factors such as congestion, bandwidth, or distance. Such systems can easily become unstable due to irregular or varying time delays. A passivity concept has been used as the framework to solve the stability problem in bilateral control of teleoperation systems and we demonstrate in this paper how to recover both passivity and tracking performance using a novel control architecture that incorporates time varying gains into the transmission path, feedforward, and feedback position control. Simulation results for a single-degree of freedom master/ slave system are presented which demonstrates the performance of the resulting control architecture.

Transparent four-channel bilateral control architecture using modified wave variable controllers under time delays

Robotica ◽  
2014 ◽  
Vol 34 (4) ◽  
pp. 859-875 ◽  
Author(s):  
Da Sun ◽  
Fazel Naghdy ◽  
Haiping Du
Keyword(s):  
Time Delays ◽  
Large Time ◽  
Wave Transformation ◽  
Bilateral Teleoperation ◽  
Bilateral Control ◽  
Wave Variable ◽  
Guarantee System ◽  
Remote Environment ◽  
The Stability ◽  
Teleoperation Systems

SUMMARYStability and transparency are two critical indices of bilateral teleoperation systems. The wave variable method is a conservative approach to robustly guarantee system passivity under arbitrary constant time delays. However, the wave-variable-based reflection is an intrinsic problem in this method because it can significantly degrade system transparency and disorient the operator's perception of the remote environment. In order to enhance both the transparency and the stability of bilateral teleoperation systems in the presence of large time delays, a new four-channel (4-CH) architecture is proposed which applies two modified wave-transformation controllers to reduce wave-based reflections. Transparency and stability of the proposed system are analyzed and the improvement in these when using this method is measured experimentally. Results clearly demonstrate that the proposed method can produce high transparency and stability even in the presence of large time delays.

scholarly journals Anisochronic Internal Model Control Design

10.14311/482 ◽  
2003 ◽  
Vol 43 (5) ◽  
Author(s):  
T. Vyhlídal ◽  
P. Zítek
Keyword(s):  
System Dynamics ◽  
Internal Model ◽  
Closed Loop ◽  
Control Design ◽  
Internal Model Control ◽  
Loop System ◽  
Closed Loop System ◽  
First Order ◽  
Dominant Pole ◽  
Model Control

The features of internal model control (IMC) design based on the first order anisochronic model are investigated in this paper. The structure of the anisochronic model is chosen in order to fit both the dominant pole and the dominant zero of the system dynamics being approximated. Thanks to its fairly plain structure, the model is suitable for use in IMC design. However, use of the anisochronic model in IMC design may result in so-called neutral dynamics of the closed loop. This phenomenon is studied in this paper via analysing the spectra of the closed loop system.

scholarly journals Consensus for Multiagent Systems with Nonlinear Dynamics and Time Delays Using a Two-Hop Relay Adaptive Method

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Qian Cao ◽  
Y. D. Song ◽  
Lei Wang ◽  
Feng Yang
Keyword(s):  
Nonlinear Dynamics ◽  
Multiagent Systems ◽  
Adaptive Algorithm ◽  
Time Delays ◽  
Closed Loop ◽  
Adaptive Method ◽  
Closed Loop System ◽  
Consensus Protocol ◽  
The Stability ◽  
Delay Margin

This paper investigates the consensus problem for multiagent systems with nonlinear dynamics and time delays. A distributed adaptive consensus protocol is proposed in which the time delays are explicitly included in the adaptive algorithm. It is shown that the resultant closed loop system involves doubly larger time delays, making the stability analysis nontrivial. Stability condition on maximum tolerable time delay is established and controlled by the proposed two-hop adaptive algorithm. The explicit expression of the delay margin is derived and analyzed in the frequency domain. Both the agent state errors and the estimation parameter errors converge to zero. A simulation example is illustrated to verify the theory results.

scholarly journals Extending model-mediation method to multi-degree-of-freedom teleoperation systems experiencing time delays in communication

Robotica ◽  
2015 ◽  
Vol 35 (5) ◽  
pp. 1121-1136 ◽  
Author(s):  
Emre Uzunoğlu ◽  
Mehmet İsmet Can Dede
Keyword(s):  
Time Delays ◽  
Control Algorithm ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Test Results ◽  
Bilateral Teleoperation ◽  
Extended Version ◽  
Teleoperation System ◽  
Teleoperation Systems ◽  
Three Degrees Of Freedom

SUMMARYIn this study, a bilateral teleoperation control algorithm is developed in which the model-mediation method is integrated with an impedance controller. The model-mediation method is also extended to three-degrees-of-freedom teleoperation. The aim of this controller is to compensate for instability issues and excessive forcing applied to the slave environment stemming from time delays in communication. The proposed control method is experimentally tested with two haptic desktop devices. Test results indicate that stability and passivity of the bilateral teleoperation system is preserved under variable time delays in communication. It is also observed that safer interactions of the slave system with its environment can be achieved by utilizing an extended version of the model-mediation method with an impedance controller.

Internal Model Control–Proportional Integral Derivative–Fractional-Order Filter Controllers Design for Unstable Delay Systems

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Kahina Titouche ◽  
Rachid Mansouri ◽  
Maamar Bettayeb ◽  
Ubaid M. Al-Saggaf
Keyword(s):  
Fractional Order ◽  
Internal Model ◽  
Closed Loop ◽  
Control Structure ◽  
Internal Model Control ◽  
Loop System ◽  
Proportional Integral Derivative ◽  
Closed Loop System ◽  
Proportional Integral ◽  
Model Control

An analytical design for proportional integral derivative (PID) controller cascaded with a fractional-order filter is proposed for first-order unstable processes with time delay. The design algorithm is based on the internal model control (IMC) paradigm. A two degrees-of-freedom (2DOF) control structure is used to improve the performance of the closed-loop system. In the 2DOF control structure, an integer order controller is used to stabilize the inner-loop, and a fractional-order controller for the stabilized system is employed to improve the performance of the closed-loop system. The Walton–Marshall's method, which is applicable to quasi-polynomials, is then used to establish the internal stability condition of the closed-loop system (the fractional part of the controller in particular) and to seek the set of stabilizing proportional (P) or proportional-derivative (PD) controller parameters.

scholarly journals Control of teleoperation systems in the presence of cyber attacks: A survey

2021 ◽  
Vol 10 (3) ◽  
pp. 235
Author(s):  
Mutaz M. Hamdan ◽  
Magdi S. Mahmoud
Keyword(s):  
Communication Network ◽  
Control Systems ◽  
Control Design ◽  
Main Idea ◽  
Cyber Attacks ◽  
Bilateral Teleoperation ◽  
Teleoperation System ◽  
Comprehensive Survey ◽  
The Stability ◽  
Teleoperation Systems

<p>The teleoperation system is often composed of a human operator, a local master manipulator, and a remote slave manipulator that are connected by a communication network. This paper proposes a survey on feedback control design for the bilateral teleoperation systems (BTSs) in nominal situations and in the presence of cyber-attacks. The main idea of the presented methods is to achieve the stability of a delayed bilateral teleoperation system in the presence of several kinds of cyber attacks. In this paper, a comprehensive survey on control systems for BTSs under cyber-attacks is discussed. Finally, we discuss the current and future problems in this field.</p>

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