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

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.

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Lucio R. Salinas ◽  
Emanuel Slawiñski ◽  
Vicente A. Mut

This paper proposes the use of simple proportional plus damping injection (P+d) controllers for delayed bilateral teleoperation of a rotorcraft UAV. The proposed control scheme involves P+d remote and local controllers, considers master and slave dynamics, and takes into account asymmetric time-varying delays. The stability of the proposed teleoperation system is analyzed using Lyapunov-Krasovskii functionals and delay-dependent stability criteria are obtained under linear-matrix-inequalities conditions. The performance of the teleoperation scheme is tested driving a virtual nonlinear 6DOF dynamic model of a minihelicopter in a human-in-the-loop simulation.


Author(s):  
A. Monemian Esfahani ◽  
S. M. Rezaei ◽  
M. Zareinejad

Friction forces in the robot joints insert nonlinearity in the dynamic and make errors in tracking. In this paper a new impedance control for the master is proposed to achieve force tracking. In addition, an impedance control for slave combined with sliding mode, which is based on perturbation estimation, is anticipated to reach position tracking. Friction compensators typically include a friction observer that provides a cancellation term in order to be added to the control input. Estimating and compensating the friction and other uncertainties will change the nonlinear equation to a linear one. The stability of entire system under time delay is guaranteed by Llewellyn’s absolute stability criterion. Performance of the proposed controllers is investigated through experiments.


Author(s):  
H. Amini ◽  
S. M. Rezaei ◽  
Ahmed A. D. Sarhan ◽  
J. Akbari ◽  
N. A. Mardi

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.


Robotica ◽  
2015 ◽  
Vol 34 (9) ◽  
pp. 2151-2161 ◽  
Author(s):  
E. Slawiñski ◽  
S. García ◽  
L. Salinas ◽  
V. Mut

SUMMARYThis paper proposes a control scheme applied to the delayed bilateral teleoperation of mobile robots with force feedback in face of asymmetric and time-varying delays. The scheme is managed by a velocity PD-like control plus impedance and a force feedback based on damping and synchronization error. A fictitious force, depending on the robot motion and its environment, is used to avoid possible collisions. In addition, the stability of the system is analyzed from which simple conditions for the control parameters are established in order to assure stability. Finally, the performance of the delayed teleoperation system is shown through experiments where a human operator drives a mobile robot.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Franco Penizzotto ◽  
Sebastian García ◽  
Emanuel Slawiñski ◽  
Vicente Mut

This paper proposes a control scheme applied to the delayed bilateral teleoperation of wheeled robots with force feedback, considering the performance of the operator’s command execution. In addition, the stability of the system is analyzed taking into account the dynamic model of the master as well as the remote mobile robot under asymmetric and time-varying delays of the communication channel. Besides, the performance of the teleoperation system, where a human operator drives a 3D simulator of a wheeled dynamic robot, is evaluated. In addition, we present an experiment where a robot Pioneer is teleoperated, based on the system architecture proposed.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Yuling Li

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.


Robotica ◽  
2014 ◽  
Vol 33 (1) ◽  
pp. 61-86 ◽  
Author(s):  
Linping Chan ◽  
Fazel Naghdy ◽  
David Stirling ◽  
Matthew Field

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.


Author(s):  
Mojtaba Sharifi ◽  
Saeed Behzadipour ◽  
Hassan Salarieh

A bilateral nonlinear adaptive impedance controller is proposed for the control of multi-degrees-of-freedom (DOF) teleoperation systems. In this controller, instead of conventional position and/or force tracking, the impedance of the nonlinear teleoperation system is controlled. The controller provides asymptotic tracking of two impedance models in Cartesian coordinates for the master and slave robots. The proposed bilateral controller can be used in different medical applications, such as telesurgery and telerehabilitation, where the impedance of the robot in interaction with human subject is of great importance. The parameters of the two impedance models can be adjusted according to the application and corresponding objectives and requirements. The dynamic uncertainties are considered in the model of the master and slave robots. The stability and the tracking performance of the system are proved via a Lyapunov analysis. Moreover, the adaptation laws are proposed in the joint space for reducing the computational complexity, however, the controller and the stability proof are all presented in Cartesian coordinates. Using simulations on a 2DOF robot, the effectiveness of the proposed controller is investigated in telesurgery and telerehabilitation operations.


2013 ◽  
Vol 392 ◽  
pp. 355-360
Author(s):  
Young Won Chang ◽  
Olga Kostiyukova ◽  
Kil To Chong

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.


Author(s):  
Mutaz M. Hamdan ◽  
Magdi S. Mahmoud

<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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