Bilateral Adaptive Control of Nonlinear Teleoperation Systems With Uncertain Dynamics and Dead-Zone

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Xia Liu ◽  
Mahdi Tavakoli
Keyword(s):  
Adaptive Control ◽  
Function Analysis ◽  
Dead Zone ◽  
Adaptive Controller ◽  
Bilateral Control ◽  
Uncertain Dynamics ◽  
Teleoperation System ◽  
Control Scheme ◽  
Teleoperation Systems ◽  
Dynamic Uncertainties

Dead-zone is one of the most common hard nonlinearities ubiquitous in master–slave teleoperation systems, particularly in the slave robot joints. However, adaptive control techniques applied in teleoperation systems usually deal with dynamic uncertainty but ignore the presence of dead-zone. Dead-zone has the potential to remarkably deteriorate the transparency of a teleoperation system in the sense of position and force tracking performance or even destabilizing the system if not compensated for in the control scheme. In this paper, an adaptive bilateral control scheme is proposed for nonlinear teleoperation systems in the presence of both uncertain dynamics and dead-zone. An adaptive controller is designed for the master robot with dynamic uncertainties and the other is developed for the slave robot with both dynamic uncertainties and unknown dead-zone. The two controllers are incorporated into the four-channel bilateral teleoperation control framework to achieve transparency. The transparency and stability of the closed-loop teleoperation system is studied via a Lyapunov function analysis. Comparisons with the conventional adaptive control which merely deal with dynamic uncertainties in the simulations demonstrate the validity of the proposed approach.

scholarly journals Adaptive Control of Teleoperation Systems With Linearly and Nonlinearly Parameterized Dynamic Uncertainties

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Xia Liu ◽  
Mahdi Tavakoli
Keyword(s):  
Adaptive Control ◽  
Function Analysis ◽  
Tracking Errors ◽  
Adaptive Controllers ◽  
Control Framework ◽  
Control Scheme ◽  
Force Tracking ◽  
Nonlinearly Parameterized ◽  
Teleoperation Systems ◽  
Dynamic Uncertainties

Existing work concerning adaptive control of uncertain teleoperation systems only deals with linearly parameterized (LP) dynamic uncertainties. Typical teleoperation system dynamics, however, also posses terms with nonlinearly parameterized (NLP) structures. An example of such terms is friction, which is ubiquitous in the joints of the master and slave robots of practical teleoperation systems. Uncertainties in the NLP dynamic terms may lead to significant position and force tracking errors if not compensated for in the control scheme. In this paper, adaptive controllers are designed for the master and slave robots with both LP and NLP dynamic uncertainties. Next, these controllers are incorporated into the 4-channel bilateral teleoperation control framework to achieve transparency. Then, transparency of the overall teleoperation is studied via a Lyapunov function analysis. Simulation studies demonstrate the effectiveness of the proposed adaptive scheme when exact knowledge of the LP and NLP dynamics is unavailable.

Bilateral coordination control of flexible master–slave manipulators using a partial differential equation model

2020 ◽  
pp. 107754632094547
Author(s):  
Le Li ◽  
Hongjun Yang ◽  
Jinkun Liu
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Dynamic Model ◽  
Vibration Suppression ◽  
Equation Model ◽  
Partial Differential ◽  
Bilateral Coordination ◽  
Teleoperation System ◽  
Control Scheme ◽  
Teleoperation Systems

In this study, we evaluate the coordination tracking control problem of a flexible master–slave teleoperation system. The system under consideration is based on a dynamic model described by a set of partial differential equations. Existing research on bilateral controllers is based on teleoperation systems composed of rigid master robots and rigid or flexible slave robots. In this work, we consider teleoperation systems with flexible master and slave robots. We dynamically model flexible master–slave manipulators using partial differential equations. Based on the dynamic model, a bilateral coordination controller is developed to realize the coordination angle tracking and vibration suppression of flexible master–slave manipulators. The teleoperation system is proven to be asymptotically stable under the control scheme. Numerical simulation results illustrate that the proposed controller is effective.

Modelling and Adaptive Control of Tendon-Driven Micromanipulators in the Presence of Van-der-Waals Forces

2004 ◽  
Author(s):  
Athanasios Tsoukalas ◽  
Anthony Tzes
Keyword(s):  
Adaptive Control ◽  
Design Problem ◽  
Van Der Waals ◽  
Adaptive Controller ◽  
Simulation Studies ◽  
Unknown Parameters ◽  
Actuation Mechanism ◽  
Control Scheme ◽  
Driven System ◽  
Adaptive Control Scheme

In this article, the design problem of an adaptive controller for a robotic micromanipulator, including the effects of the applied Van der Waals (VdW) forces is considered. The micro-manipulator’s dynamic model is appropriately modified in order to include the interaction of the attractive VdW-forces. Inhere, every link is decomposed into a series of elementary particles (e.g. spheres), each one interacting with the robot’s neighboring objects during its motion. This interaction induces nonlinear additive terms in the model, attributed to the overall effect of the VdW-forces. The actuation is achieved by a tendon-driven system. At each joint, a pair of tendons is attached and act in an almost passive antagonistic manner. The kinematic and dynamic analysis of the tendon-driven actuation mechanism is offered. Consequently, the microrobot’s model is shown to be linearly parameterizable. Subject to this observation, a globally stabilizable adaptive control scheme is derived, estimating the unknown parameters (masses, generalized VdW-forces) and compensating any variations of those. Simulation studies on a 2-DOF micro-manipulator are offered to highlight the effectiveness of the proposed scheme.

An Adaptively Controlled Electrohydraulic Servo-Mechanism: Part 1: Adaptive Controller Design

1987 ◽  
Vol 201 (3) ◽  
pp. 175-180 ◽  
Author(s):  
K A Edge ◽  
K R A Figueredo
Keyword(s):  
Adaptive Control ◽  
Controller Design ◽  
Control Design ◽  
Adaptive Controller ◽  
Adaptive Control System ◽  
Sampled Data ◽  
Robust Controller ◽  
Servo Mechanism ◽  
Control Scheme ◽  
Model Reference Adaptive

A systematic model reference adaptive control design scheme is presented. The control scheme is developed and analysed within the framework of a sampled data system with a parameter adaptive algorithm designed on the basis of hyper stability theory. A number of supervisory functions are used to supplement the basic adaptive control system in order to enhance robust controller action.

A New Approach to Adaptive Control of Manipulators

1987 ◽  
Vol 109 (3) ◽  
pp. 193-202 ◽  
Author(s):  
H. Seraji
Keyword(s):  
Adaptive Control ◽  
A Priori ◽  
Adaptive Controller ◽  
Operating Point ◽  
Adaptation Algorithm ◽  
New Approach ◽  
Control Scheme ◽  
Auxiliary Signal ◽  
Feedforward Controller ◽  
Parameter Values

The paper presents a new approach to adaptive control of manipulators to achieve trajectory tracking by the joint angles. The central concept in this approach is the utilization of the manipulator “inverse” as a feedforward controller. The desired trajectory is applied as an input to the feedforward controller which “behaves” as the “inverse” of the manipulator at any operating point; and the controller output is used as the driving torque for the manipulator. The controller gains are then updated by an adaptation algorithm derived from MR AC theory to cope with variations in the manipulator inverse due to changes of the operating point. An adaptive feedback controller and an auxiliary signal are also used to enhance closed-loop stability and to achieve faster adaptation. The proposed control scheme is computationally fast and does not require a priori knowledge of the complex dynamic model or the parameter values of the manipulator or the payload. Simulation results are presented in support of the proposed adaptive control scheme. The results demonstrate that the adaptive controller performs remarkably well for different reference trajectories and despite gross variations in the payload.

scholarly journals Neural Networks Approximator Based Robust Adaptive Controller Design of Hypersonic Flight Vehicles Systems Coupled with Stochastic Disturbance and Dynamic Uncertainties

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Guoqiang Zhu ◽  
Lingfang Sun ◽  
Xiuyu Zhang
Keyword(s):  
Controller Design ◽  
Tracking Error ◽  
Adaptive Controller ◽  
Stochastic Disturbance ◽  
Hypersonic Flight ◽  
Flight Vehicles ◽  
Uncertain Dynamics ◽  
Robust Adaptive ◽  
And Performance ◽  
Dynamic Uncertainties

A neural network robust control is proposed for a class of generic hypersonic flight vehicles with uncertain dynamics and stochastic disturbance. Compared with the present schemes of dealing with dynamic uncertainties and stochastic disturbance, the outstanding feature of the proposed scheme is that only one parameter needs to be estimated at each design step, so that the computational burden can be greatly reduced and the designed controller is much simpler. Moreover, by introducing a performance function in controller design, the prespecified transient and performance of tracking error can be guaranteed. It is proved that all signals of closed-loop system are uniformly ultimately bounded. The simulation results are carried out to illustrate effectiveness of the proposed control algorithm.

Flutter Suppression of Wind Turbine Blade Using Adaptive Control

2013 ◽  
Author(s):  
Nailu Li ◽  
Mark J. Balas
Keyword(s):  
Adaptive Control ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Adaptive Controller ◽  
Wind Turbine Blade ◽  
Aeroelastic System ◽  
Aerodynamic Loads ◽  
Flutter Suppression ◽  
Control Scheme ◽  
Trailing Edge Flap

The variation of aeroelastic system dynamics is treated as the change of time-varying aerodynamic loads over rotating wind turbine blade. An Adaptive Control scheme is introduced to suppress blade fluttering, caused by unsteady aerodynamic loads, with trailing-edge flap. The robustness and effectiveness of designed Adaptive Controller are shown by good simulation results. For stability analysis, the proposed Adaptive Stability Theorem is proved theoretically by Kalman-Yacubovic Lemma and also illustrated numerically by certain case.

scholarly journals Adaptive Control for Nonlinear Systems with Time-Varying Control Gain

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Alejandro Rincon ◽  
Fabiola Angulo
Keyword(s):  
Adaptive Control ◽  
Dead Zone ◽  
Permanent Magnet Synchronous Motor ◽  
Adaptive Robust Control ◽  
Type Model ◽  
Time Varying ◽  
Plant Model ◽  
Control Gain ◽  
Control Scheme ◽  
Nonlinear Plants

We propose a scheme for nonlinear plants with time-varying control gain and time-varying plant coefficients, on the basis of a plant model consisting of a Brunovsky-type model with polynomials as approximators. We develop an adaptive robust control scheme for this plant, under the following assumptions: (i) the plant terms involve time-varying but bounded coefficients, being its upper bound unknown; (ii) the control gain is unknown, not necessarily bounded, and only its signum is known. To achieve robustness, we use a combination of robustifying control inputs and dead zone-type update laws. We apply this methodology to the speed control of a permanent magnet synchronous motor (PMSM), and we achieve proper tracking results.

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