scholarly journals Nonlinear bilateral teleoperation using extended active observer for force estimation and disturbance suppression

Robotica ◽  
2014 ◽  
Vol 33 (1) ◽  
pp. 61-86 ◽  
Author(s):  
Linping Chan ◽  
Fazel Naghdy ◽  
David Stirling ◽  
Matthew Field
Keyword(s):  
Position Tracking ◽  
Bilateral Teleoperation ◽  
Force Estimation ◽  
Teleoperation System ◽  
Inertial Parameters ◽  
Disturbance Suppression ◽  
Force Tracking ◽  
Accurate Position ◽  
Teleoperation Systems ◽  
Robot Position

SUMMARYA novel nonlinear teleoperation algorithm for simultaneous inertial parameters and force estimation at the master and slave sides of the teleoperation system is proposed. The scheme, called Extended Active Observer (EAOB), is an extension of the existing active observer. It provides effective force tracking at the master side with accurate position tracking at the slave side in the presence of inertial parameter variation and measurement noise. The proposed method only requires the measurement of robot position, and as a result significantly reduces the difficulty and cost of implementing bilateral teleoperation systems. The approach is described and its stability is analytically verified. The performance of the method is validated through computer simulation and compared with the Nicosia observer-based controller. According to the results, EAOB outperforms the Nicosia observer method and effectively rejects noise.

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.

Performance analysis in delayed nonlinear bilateral teleoperation systems by force estimation algorithm

2017 ◽  
Vol 40 (5) ◽  
pp. 1637-1644
Author(s):  
Farhad Azimifar ◽  
Kamran Hassani ◽  
Amir Hossein Saveh ◽  
Farhad Tabatabai Ghomshe
Keyword(s):  
Closed Loop ◽  
Force Measurement ◽  
Estimation Algorithm ◽  
Lyapunov Theory ◽  
Bilateral Teleoperation ◽  
Force Estimation ◽  
Teleoperation System ◽  
Control Scheme ◽  
Teleoperation Systems ◽  
System With Time Delay

This paper establishes a novel control strategy for a nonlinear bilateral teleoperation system with time delay. Besides position and velocity signals, force signals are additionally utilized in the control scheme. This modification significantly improves the poor transparency during contact with the environment. To eliminate the external force measurement, a force estimation algorithm is proposed for the master and slave robots. The closed loop stability of the nonlinear teleoperation system with the proposed control scheme is investigated through the Lyapunov theory. Furthermore, it is theoretically and experimentally proved that force reflection occurs and transparency is enhanced simultaneously. Consequently, experimental results verify the efficiency of the new control scheme in free motion and during collision of the slave robot with the environment.

scholarly journals An Adaptive Regulator for Space Teleoperation System in Task Space

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Chao Ge ◽  
Weiwei Zhang ◽  
Hong Wang ◽  
Xiaoyi Li
Keyword(s):  
Outer Space ◽  
Joint Space ◽  
Position Tracking ◽  
Time Varying ◽  
Bilateral Teleoperation ◽  
Task Space ◽  
Teleoperation System ◽  
Accurate Position ◽  
Gravity Signal ◽  
Adaptive Regulator

The problem of the gravity information which can not be obtained in advance for bilateral teleoperation is studied. In outer space exploration, the gravity term changes with the position changing of the slave manipulator. So it is necessary to design an adaptive regulator controller to compensate for the unknown gravity signal. Moreover, to get a more accurate position tracking performance, the controller is designed in the task space instead of the joint space. Additionally, the time delay considered in this paper is not only time varying but also unsymmetrical. Finally, simulations are presented to show the effectiveness of the proposed approach.

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.

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.

FPAA-Based Control of Bilateral Teleoperation Systems for Enhanced User Task Performance

2017 ◽  
Vol 26 (2) ◽  
pp. 210-227 ◽  
Author(s):  
Ting Yang ◽  
Junfeng Hu ◽  
Wei Geng ◽  
Yili Fu ◽  
Mahdi Tavakoli
Keyword(s):  
Task Performance ◽  
Discrete Time ◽  
Sampling Period ◽  
Bilateral Teleoperation ◽  
System A ◽  
Programmable Analog ◽  
Teleoperation System ◽  
Field Programmable ◽  
Teleoperation Systems ◽  
Field Programmable Analog Array

In a bilateral teleoperation system, discrete-time implementation of the controller can cause performance degradation. This is due to a well-known stability-imposed upper bound on the product of the discrete-time controller's gain and the sampling period. In this article, for a bilateral teleoperation system, a continuous-time controller based on a Field Programmable Analog Array (FPAA) is deployed and compared in terms of performance with its discrete-time counterpart. Experimental results show that, unlike the discrete-time controller, the FPAA-based controller helps the human user complete teleoperation tasks that require high controller gains such as when a large impedance needs to be displayed against the user's hand. Also, an experimental object stiffness discrimination study shows that large sampling periods, necessitating low control gains for maintaining stability, lead to unacceptable task performance by the user; however, the users show an improved ability to discriminate the various objects if the teleoperation controller is implemented using an FPAA.

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.

A novel multilateral teleoperation scheme with power-based time-domain passivity control

2016 ◽  
Vol 40 (11) ◽  
pp. 3252-3262 ◽  
Author(s):  
Zheng Chen ◽  
Ya-Jun Pan ◽  
Jason Gu ◽  
Shane Forbrigger
Keyword(s):  
Time Domain ◽  
Communication Channel ◽  
Communication Channels ◽  
Bilateral Teleoperation ◽  
Communication Structure ◽  
Remote Operation ◽  
Teleoperation System ◽  
Control Scheme ◽  
Weighting Coefficients ◽  
Teleoperation Systems

Multilateral teleoperation systems, which are extended from the traditional bilateral teleoperation, have become subject to increasing attention in current years, with increasing industrial requirements, such as the remote operation of larger objects and more complex tasks. In this paper, a general multilateral teleoperation control problem is discussed, in which n masters remotely control n slaves through delayed communication channels. A novel communication structure is proposed to satisfy the multiple master–slave communication requirement, in which weighting coefficients are chosen freely to perform the weighted effects of different masters or slaves. Power-based time-domain passivity control is subsequently developed for the complex multiple master–slave communication channel, to achieve the passivity of multilateral teleoperation systems under time delay. Experiments on a teleoperation system with two masters and two slaves are described; the results verify the effectiveness of the proposed control scheme.

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.

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