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>

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.

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.

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.

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.

scholarly journals Energy-Optimized Consensus Formation Control for the Time-Delayed Bilateral Teleoperation System of UAVs

2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Hui-yu Sun ◽  
Guang-ming Song ◽  
Zhong Wei ◽  
Ying Zhang
Keyword(s):  
Energy Dissipation ◽  
Formation Control ◽  
Communication Complexity ◽  
Environmental Constraints ◽  
Bilateral Teleoperation ◽  
Consensus Formation ◽  
Human In The Loop ◽  
Teleoperation System ◽  
Force Tracking ◽  
The Stability

This paper proposes an energy-optimized consensus formation scheme for the time-delayed bilateral teleoperation system of multiple unmanned aerial vehicles (UAVs) in the obstructed environment. To deal with the asymmetric time-varying delays in aerial teleoperation, the local damping is independently distributed on both sides to enforce consensus formation and force tracking of the master haptic device and the slave UAVs. The stability of the time-delayed aerial teleoperation system is analyzed by the Lyapunov function. In addition, a flux-conserved force field is incorporated into the aerial teleoperation system to guarantee a collision-free consensus formation in the obstructed environment. Moreover, to reduce the communication complexity and energy dissipation of the formation, a top-down strategy of 3D optimal persistent graph is first proposed to optimize the formation topology. Under the optimized topology with environmental constraints, communication complexity and energy dissipation can be minimized while the rigid formation can be maintained and transformed persistently in the obstructed environment. Finally, the human-in-the-loop simulations are performed to validate the effectiveness of the proposed scheme.

Perceptuo-Motor Transparency in Bilateral Teleoperation

2008 ◽  
Author(s):  
Ilana Nisky ◽  
Ferdinando A. Mussa-Ivaldi ◽  
Amir Karniel
Keyword(s):  
Force Feedback ◽  
Human Operator ◽  
Bilateral Teleoperation ◽  
Laplace Domain ◽  
Teleoperation System ◽  
Teleoperation Systems ◽  
And Training ◽  
Local Motor ◽  
Training Protocol ◽  
The Ideal

In bilateral teleoperation, the operator holds a local robot which determines the motion of a remote robot and continuously receives delayed force feedback. Transparency is a measure of teleoperation system fidelity. The ideal teleoperator system is the identity channel, in which there is neither delay nor distortion. During the last decades transparency was widely analyzed using two-port hybrid representation of the system in Laplace domain. Such representations define hybrid matrix that maps between the transmission channel inputs and outputs. However, in measuring transparency one should consider also the human operator, and therefore we propose a multidimensional measure of transparency which takes into account: i) Perceptual transparency: The human operator cannot distinguish when the teleoperation channel is being replaced by an identity channel. ii) Local Motor transparency: The movement of the operator does not change when the teleoperation channel is replaced by an identity channel. iii) Remote transparency: The movement of the remote robot does not change when the teleoperation channel is replaced by an identity channel. We hypothesize that by selecting filters and training protocol it is possible to obtain perceptually transparent teleoperation (i) and remote motor transparency (iii) without local motor transparency (ii), namely, to transparentize the system. We formally define the transparency error, analyze this process in the linear case, and simulate simplified teleoperation system according to typical experimental results in our previous studies about perception of delayed stiffness. We believe that these tools are essential in developing functional teleoperation systems.

A New Matching Condition for Nonlinear Robust Control Design

1995 ◽  
Vol 117 (4) ◽  
pp. 453-458 ◽  
Author(s):  
Y. H. Chen
Keyword(s):  
Control Design ◽  
Main Idea ◽  
Matching Condition ◽  
Worst Case ◽  
Uniform Ultimate Boundedness ◽  
Current Matching ◽  
Robust Control Design ◽  
The Stability ◽  
Special Case ◽  
Nonlinear Robust

We study the control design problem for uncertain nonlinear systems. A new matching condition is presented. The main idea is to explore the route through which the (worst case) uncertainty may affect the stability. This route is then used to establish the new matching condition. Compared with the previous case, the current matching condition prescribes the route nonlinearly while the early matching condition is a special case of the linear description. A class of robust controls, which guarantees practical stability, can be designed based on this new matching condition. The size of the uniform ultimate boundedness ball can be made arbitrarily small by an appropriate choice of a design parameter.

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