scholarly journals Computational Efficiency-Based Adaptive Tracking Control for Robotic Manipulators with Unknown Input Bouc–Wen Hysteresis

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2776 ◽  
Author(s):  
Kan Xie ◽  
Yue Lai ◽  
Weijun Li
Keyword(s):  
Computational Efficiency ◽  
Closed Loop ◽  
Tracking Error ◽  
Control Unit ◽  
Robotic Manipulators ◽  
Lyapunov Theory ◽  
Loop System ◽  
Unknown Input ◽  
Closed Loop System ◽  
Adaptive Tracking Control

In order to maintain robotic manipulators at a high level of performance, their controllers should be able to address nonlinearities in the closed-loop system, such as input nonlinearities. Meanwhile, computational efficiency is also required for real-time implementation. In this paper, an unknown input Bouc–Wen hysteresis control problem is investigated for robotic manipulators using adaptive control and a dynamical gain-based approach. The dynamics of hysteresis are modeled as an additional control unit in the closed-loop system and are integrated with the robotic manipulators. Two adaptive parameters are developed for improving the computational efficiency of the proposed control scheme, based on which the outputs of robotic manipulators are driven to track desired trajectories. Lyapunov theory is adopted to prove the effectiveness of the proposed method. Moreover, the tracking error is improved from ultimately bounded to asymptotic tracking compared to most of the existing results. This is of important significance to improve the control quality of robotic manipulators with unknown input Bouc–Wen hysteresis. Numerical examples including fixed-point and trajectory controls are provided to show the validity of our method.

Modeling and Control of an Automotive All-Wheel Drive Clutch as a Piecewise Affine System

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Shiming Duan ◽  
Jun Ni ◽  
A. Galip Ulsoy
Keyword(s):  
Closed Loop ◽  
Open Loop ◽  
Lyapunov Theory ◽  
Loop System ◽  
Linear Matrix ◽  
Closed Loop System ◽  
Modeling And Control ◽  
Piecewise Affine ◽  
Wheel Drive ◽  
And Control

Piecewise affine (PWA) systems belong to a subclass of switched systems and provide good flexibility and traceability for modeling a variety of nonlinear systems. In this paper, application of the PWA system framework to the modeling and control of an automotive all-wheel drive (AWD) clutch system is presented. The open-loop system is first modeled as a PWA system, followed by the design of a piecewise linear (i.e., switched) feedback controller. The stability of the closed-loop system, including model uncertainty and time delays, is examined using linear matrix inequalities based on Lyapunov theory. Finally, the responses of the closed-loop system under step and sine reference signals and temperature disturbance signals are simulated to illustrate the effectiveness of the design.

scholarly journals Composite Immersion and Invariance Based Adaptive Attitude Control of Asteroid-Orbiting Spacecraft in Elliptic Orbit

2021 ◽  
Author(s):  
Keum W Lee ◽  
Sahjendra N Singh
Keyword(s):  
Attitude Control ◽  
Closed Loop ◽  
Tracking Error ◽  
Loop System ◽  
Closed Loop System ◽  
Immersion And Invariance ◽  
State Dependent ◽  
Dependent Vector ◽  
Yaw Angle ◽  
Angle Tracking

Abstract This paper proposes a new composite noncertainty-equivalence adaptive (CNCEA) control system for the attitude (roll, pitch, and yaw angle) control of a spacecraft in an orbit around a uniformly rotating asteroid based on the immersion and invariance (I&I) theory. For the design, it is assumed that the asteroid's gravitational parameters and the spacecraft's inertia matrix are not known. In contrast to certainty-equivalence adaptive (CEA) or noncertainty-equivalence adaptive (NCEA) systems, the CNCEA attitude control system's composite identifier uses the attitude angle tracking error, a nonlinear state-dependent vector function, and model prediction error for parameter estimation. The Lyapunov analysis shows that in the closed-loop system, the Euler angles asymptotically track the reference attitude trajectories. Interestingly, there exist two parameter error-dependent attractive manifolds, to which the closed-loop system's trajectories converge. Moreover, the composite identifier using two types of error signals provides stronger stability properties in the closed-loop system. Simulation results are presented for the attitude control of a spacecraft orbiting in the vicinity of the asteroid 433 Eros. These results show precise nadir pointing attitude regulation, despite uncertainties in the system.

Adaptive Fuzzy Finite-Time Command-Filtered Backstepping Control of Flexible-Joint Robots

Robotica ◽  
2020 ◽  
pp. 1-20
Author(s):  
Roger Datouo ◽  
Joseph Jean-Baptiste Mvogo Ahanda ◽  
Achille Melingui ◽  
Frédéric Biya-Motto ◽  
Bernard Essimbi Zobo
Keyword(s):  
Finite Time ◽  
Closed Loop ◽  
Computational Cost ◽  
Backstepping Control ◽  
Lyapunov Theory ◽  
Loop System ◽  
Closed Loop System ◽  
Flexible Joint ◽  
Adaptive Fuzzy ◽  
Finite Time Stabilization

SUMMARY The problem of finite-time tracking control for n-link flexible-joint robot manipulators is addressed. An adaptive fuzzy finite-time command-filtered backstepping control scheme is presented to solve the following problems: “explosion of terms” problem, finite-time stabilization of the closed-loop system, and the reduction of computational cost. To this end, new virtual adaptive control signals and new finite-time error compensation mechanism are constructed using inherent properties of robot manipulator systems. Based on the Lyapunov theory, the finite-time stabilization of the closed-loop system is proved. Simulation studies show the effectiveness of the proposed method.

Fault Tolerant Control and Classification for Longitudinal Vehicle Control

2003 ◽  
Vol 125 (3) ◽  
pp. 320-329 ◽  
Author(s):  
Bongsob Song ◽  
J. Karl Hedrick ◽  
Adam Howell
Keyword(s):  
Closed Loop ◽  
Fault Tolerant ◽  
Optimization Technique ◽  
Tracking Error ◽  
Fault Detection And Diagnosis ◽  
Loop System ◽  
Fault Classification ◽  
Closed Loop System ◽  
Dynamic Surface ◽  
Performance Loss

In this paper, a new method of analyzing for the performance loss caused by faults in the systems is presented, and applied to the design of a fault tolerant longitudinal controller for a transit bus. Based on the amount of performance loss measured by a quadratic function, fault impact assessment is developed for both single and multiple faults. More specifically, ellipsoidal approximation of the tracking error bounds via dynamic surface control (DSC) is obtained via convex optimization technique for the nonlinear closed-loop system. Relying on the fault impact to the closed loop system and its isolatability on a fault detection and diagnosis system, the fault classification is proposed to provide a switching logic in the framework of a switched hierarchical structure. Finally, simulation results of the fault tolerant controller and corresponding fault classification are shown for multiple multiplicative faults.

Robust adaptive command filtered control of a robotic manipulator with uncertain dynamic and joint space constraints

Robotica ◽  
2018 ◽  
Vol 36 (5) ◽  
pp. 767-786 ◽  
Author(s):  
Joseph Jean-Baptiste Mvogo Ahanda ◽  
Jean Bosco Mbede ◽  
Achille Melingui ◽  
Bernard Essimbi Zobo
Keyword(s):  
Closed Loop ◽  
Robotic Manipulator ◽  
Joint Space ◽  
Robust Adaptive Control ◽  
Lyapunov Theory ◽  
Loop System ◽  
Support Vector ◽  
Closed Loop System ◽  
Uncertain Dynamics ◽  
Robust Adaptive

SUMMARYThe problem of robust adaptive control of a robotic manipulator subjected to uncertain dynamics and joint space constraints is addressed in this paper. Command filters are used to overcome the time derivatives of virtual control, thus reducing the need for desired trajectory differentiations. A barrier Lyapunov function is used to deal with the joint space constraints. A robust adaptive support vector regression architecture is used to reduce filtering errors, approximation errors and handle dynamic uncertainties. The stability analysis of the closed-loop system using the Lyapunov theory permits to highlight adaptation laws and to prove that all signals of the closed-loop system are bounded. Simulations show the effectiveness of the proposed control strategy.

A Theoretical Control Strategy for a Diesel Engine

2005 ◽  
Vol 128 (2) ◽  
pp. 453-457 ◽  
Author(s):  
R. Outbib ◽  
X. Dovifaaz ◽  
A. Rachid ◽  
M. Ouladsine
Keyword(s):  
Diesel Engine ◽  
Engine Speed ◽  
Closed Loop ◽  
Lyapunov Theory ◽  
Loop System ◽  
Control Law ◽  
Closed Loop System ◽  
Nonlinear Method ◽  
New Approach ◽  
Fuel Rate

In this paper we present a theoretical strategy for diesel engine control. More precisely, we propose a new approach to control the speed of the engine using the fuel rate as the control law and we show how this approach can be used to control the opacity. We first establish a mathematical model that describes the behavior of the engine. Afterward, we propose a new nonlinear method to design a controller for a class of nonlinear systems. The proposed method, based on Lyapunov theory, is used to design a smooth feedback law that renders the closed-loop system asymptotically stable around a desired engine speed value. Finally, simulation results are proposed to highlight the performances of the closed-loop system.

scholarly journals Actuator Saturation and Control Design for Buildings Structural Systems with Improved Uncertainty Description

2013 ◽  
Vol 20 (2) ◽  
pp. 297-308 ◽  
Author(s):  
Y.C. Ding ◽  
F.L. Weng ◽  
Z.A. Yu
Keyword(s):  
Closed Loop ◽  
Actuator Saturation ◽  
Input Saturation ◽  
Lyapunov Theory ◽  
Loop System ◽  
Structural Systems ◽  
Control Input ◽  
Closed Loop System ◽  
Parameter Uncertainties ◽  
Earthquake Excitation

The problem of robustly active vibration control for a class of earthquake-excited structural systems with time-delay and saturation in the control input channel and parameter uncertainties appearing in all the mass, damping and stiffness matrices is concerned in this paper. The objective of the designing controllers is to guarantee the robust stability of the closed-loop system and attenuate the disturbance from earthquake excitation. Firstly, by using the linear combination of some matrices to deal with the system's uncertainties, a new system uncertainties description, namely rank-1 uncertainty description, is presented. Then, by introducing a linear varying parameter, the input saturation model is described as a linear parameter varying model. Furthermore, based on parameter-dependent Lyapunov theory and linear matrix inequality (LMI) technique, the LMIs-based conditions for the closed-loop system to be stable are deduced. By solving those conditions, the controller, considering the actuator saturation, input delay and parameters uncertainties, is obtained. Finally, a three-storey linear building structure under earthquake excitation is considered and simulation results are given to show the effectiveness of the proposed controllers.

Adaptive robust stabilization of a class of uncertain non-linear systems with mismatched time-varying parameters

2011 ◽  
Vol 226 (2) ◽  
pp. 204-214 ◽  
Author(s):  
M M Arefi ◽  
M R Jahed-Motlagh
Keyword(s):  
Linear Systems ◽  
Closed Loop ◽  
Robust Stabilization ◽  
Lyapunov Theory ◽  
Loop System ◽  
Time Varying ◽  
Closed Loop System ◽  
Mismatched Uncertainties ◽  
Non Linear ◽  
Non Linear Systems

In this paper, an adaptive robust stabilization algorithm is presented for a class of non-linear systems with mismatched uncertainties. In this regard, a new controller based on the Lyapunov theory is proposed in order to overcome the problem of stabilizing non-linear time-varying systems with mismatched uncertainties. This method is such that the stability of the closed-loop system is guaranteed in the absence of the triangularity assumption. The proposed approach leads to asymptotic convergence of the states of the closed-loop system to zero for unknown but bounded uncertainties. Subsequently, this method is modified so that all the signals in the closed-loop system are uniformly ultimately bounded. Eventually, numerical simulations support the effectiveness of the given algorithm.

Sensitivity Comparison to Loop Latencies Between Damping Versus Stiffness Feedback Control Action in Distributed Controllers

2014 ◽  
Author(s):  
Ye Zhao ◽  
Nicholas Paine ◽  
Luis Sentis
Keyword(s):  
Closed Loop ◽  
Impedance Control ◽  
Tracking Error ◽  
Loop System ◽  
Tracking Performance ◽  
System Stability ◽  
Step Response ◽  
Tracking Accuracy ◽  
Closed Loop System ◽  
And Performance

This paper studies the effects of damping and stiffness feedback loop latencies on closed-loop system stability and performance. Phase margin stability analysis, step response performance and tracking accuracy are respectively simulated for a rigid actuator with impedance control. Both system stability and tracking performance are more sensitive to damping feedback than stiffness feedback latencies. Several comparative tests are simulated and experimentally implemented on a real-world actuator to verify our conclusion. This discrepancy in sensitivity motivates the necessity of implementing embedded damping, in which damping feedback is implemented locally at the low level joint controller. A direct benefit of this distributed impedance control strategy is the enhancement of closed-loop system stability. Using this strategy, feedback effort and thus closed-loop actuator impedance may be increased beyond the levels possible for a monolithic impedance controller. High impedance is desirable to minimize tracking error in the presence of disturbances. Specially, trajectory tracking accuracy is tested by a fast swing and a slow stance motion of a knee joint emulating NASA-JSC’s Valkyrie legged robot. When damping latencies are lowered beyond stiffness latencies, gravitational disturbance is rejected, thus demonstrating the accurate tracking performance enabled by a distributed impedance controller.

A Robustly Stable Multiestimation-Based Adaptive Control Scheme for Robotic Manipulators

2005 ◽  
Vol 128 (2) ◽  
pp. 414-421 ◽  
Author(s):  
A. Ibeas ◽  
M. de la Sen
Keyword(s):  
Adaptive Systems ◽  
Closed Loop ◽  
Sudden Change ◽  
Robotic Manipulators ◽  
Adaptive Controller ◽  
Time Instant ◽  
Loop System ◽  
System Stability ◽  
Closed Loop System ◽  
Control Scheme

A multiestimation-based robust adaptive controller is designed for robotic manipulators. The control scheme is composed of a set of estimation algorithms running in parallel along with a supervisory index proposed with the aim of evaluating the identification performance of each one. Then, a higher-order level supervision algorithm decides in real time the estimator that will parametrize the adaptive controller at each time instant according to the values of the above supervisory indexes. There exists a minimum residence time between switches in such a way that the closed-loop system stability is guaranteed. It is verified through simulations that multiestimation-based schemes can improve the transient response of adaptive systems as well as the closed-loop behavior when a sudden change in the parameters or in the reference input occurs by appropriate switching between the various estimation schemes running in parallel. The closed-loop system is proved to be robustly stable under the influence of uncertainties due to a poor modeling of the robotic manipulator. Finally, the usefulness of the proposed scheme is highlighted by some simulation examples.

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