Fuzzy reduced-order observer-based adaptive tracking control for a class of switched non-affine systems

2019 ◽  
Vol 42 (7) ◽  
pp. 1345-1357
Author(s):  
Chunyan Wang ◽  
Mengqi Zhang ◽  
Huan Li
Keyword(s):  
Tracking Control ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Mean Value Theorem ◽  
Dynamic Surface ◽  
Affine Systems ◽  
Reduced Order ◽  
Common Control ◽  
Reduced Order Observer ◽  
The Given

This paper investigates an adaptive fuzzy tracking control problem under arbitrary switching for a class of switched non-affine systems with completely unknown nonlinear functions and unmeasurable states. Combining with dynamic surface control (DSC) method and fuzzy approximation technique, an adaptive output-feedback common control approach is presented based on a new fuzzy reduced-order observer which is independent of any switching signal. The given design method does not rely on the boundness assumption about the control gain functions raised by the mean value theorem for non-affine systems, which contributes to the less conservation of the common controller. Meanwhile, the algebraic loop problem caused by the nonstrict-feedback structure and the repeated approximation problem in existing results are also circumvented in the given common control design process. Based on Lyapunov stability theory, the designed common controller can guarantee all the signals in the resulting closed-loop switched systems are uniformly bounded and the tracking error can converge to a small neighborhood of the origin. Two examples are provided to verify the feasibility and practicability of the proposed method.

scholarly journals Adaptive Fuzzy Fast Finite-Time Tracking Control for Nonlinear Systems in Pure-Feedback Form with Unknown Disturbance

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Ke Xu ◽  
Huanqing Wang ◽  
Xiaoping Liu ◽  
Ming Chen
Keyword(s):  
Nonlinear Systems ◽  
Finite Time ◽  
Tracking Control ◽  
Tracking Error ◽  
Adaptive Fuzzy Control ◽  
Small Neighborhood ◽  
Mean Value Theorem ◽  
Feedback Form ◽  
Adaptive Fuzzy ◽  
Unknown Disturbance

In this paper, based on the fast finite-time stability theorem, an adaptive fuzzy control problem is considered for a class of nonlinear systems in pure-feedback form with unknown disturbance. In the controller design process, the mean value theorem is applied to address the nonaffine structure of the pure-feedback plant, the universal approximation capability of the fuzzy logic system (FLS) is utilized to compensate the unknown uncertainties, and the adaptive backstepping technique is used to design the controller model. Combined with the selection of the appropriate Lyapunov function at each step, a fuzzy-based adaptive tracking control scheme is proposed, which ensures that all signals in the closed-loop system are bounded and tracking error converges to a small neighborhood of the origin in fast finite-time. Finally, simulation results illustrate the validity of the proposed approach.

Adaptive sliding tracking control for nonlinear uncertain robotic systems with unknown actuator nonlinearities

Robotica ◽  
2021 ◽  
pp. 1-20
Author(s):  
Shubo Liu ◽  
Guoquan Liu ◽  
Shengbiao Wu
Keyword(s):  
Control Problem ◽  
Prior Knowledge ◽  
Control Strategy ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Robotic Systems ◽  
Actuator Nonlinearities ◽  
Simulation Results

Abstract This study is concerned with the tracking control problem for nonlinear uncertain robotic systems in the presence of unknown actuator nonlinearities. A novel adaptive sliding controller is designed based on a robust disturbance observer without any prior knowledge of actuator nonlinearities and system dynamics. The proposed control strategy can guarantee that the tracking error eventually converges to an arbitrarily small neighborhood of zero. Simulation results are included to demonstrate the effectiveness and superiority of the proposed strategy.

scholarly journals Direct Adaptive Tracking Control for a Class of Pure-Feedback Stochastic Nonlinear Systems Based on Fuzzy-Approximation

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Huanqing Wang ◽  
Xiaoping Liu ◽  
Qi Zhou ◽  
Hamid Reza Karimi
Keyword(s):  
Nonlinear Systems ◽  
Tracking Control ◽  
Controller Design ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Adaptive Controller ◽  
Stochastic Nonlinear Systems ◽  
Fuzzy Logic Systems ◽  
Adaptive Tracking Control ◽  
Adaptive Tracking

The problem of fuzzy-based direct adaptive tracking control is considered for a class of pure-feedback stochastic nonlinear systems. During the controller design, fuzzy logic systems are used to approximate the packaged unknown nonlinearities, and then a novel direct adaptive controller is constructed via backstepping technique. It is shown that the proposed controller guarantees that all the signals in the closed-loop system are bounded in probability and the tracking error eventually converges to a small neighborhood around the origin in the sense of mean quartic value. The main advantages lie in that the proposed controller structure is simpler and only one adaptive parameter needs to be updated online. Simulation results are used to illustrate the effectiveness of the proposed approach.

A Note on a Reduced-Order Observer Based Controller for a Class of Lipschitz Nonlinear Systems

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Mohamadreza Homayounzade ◽  
Mehdi Keshmiri
Keyword(s):  
Nonlinear Systems ◽  
Global Exponential Stability ◽  
Degrees Of Freedom ◽  
Large Range ◽  
Robot Manipulator ◽  
Tracking Error ◽  
Control Law ◽  
Reduced Order ◽  
Lipschitz Nonlinear Systems ◽  
Reduced Order Observer

This paper presents a novel reduced-order observer based controller for a class of Lipschitz nonlinear systems, described by a set of second order ordinary differential equations. The control law is designed based on the measured output and estimated states. The main features are: (1) The computation cost is reduced noticeably, since the observer is a reduced-order one; (2) The controller guarantees semi-global exponential stability for both estimation and tracking error; and (3) The proposed method can be used in a large range of applications, especially in mechanical systems. The effectiveness of the proposed method is investigated through the numerical simulation for a two-degrees-of-freedom robot manipulator acting on a horizontal worktable.

scholarly journals Research on UDE control based on load torque compensation of PMSM

2021 ◽  
Vol 2137 (1) ◽  
pp. 012024
Author(s):  
Hongliang Yan ◽  
Weizhi Zhai ◽  
Yan Geng
Keyword(s):  
Control Strategy ◽  
Permanent Magnet Synchronous Motor ◽  
Tracking Error ◽  
Frequency Component ◽  
High Frequency Component ◽  
Load Torque ◽  
Reduced Order ◽  
System A ◽  
Reduced Order Observer ◽  
Disturbance Estimator

Abstract In order to solve the problem that the traditional uncertainty and disturbance estimator (UDE) control needs to increase the filter order to keep good performance when facing rapid disturbance changes, thus lead to cost increase in implementing the system, a speed control strategy of permanent magnet synchronous motor (PMSM) driver based on reduced order observer compensation is proposed. The designed control strategy is robust to the system with internal parameter variation and external torque disturbance. Through the compensation of load torque, the pressure of UDE controller is relieved, and then the tracking error of high-frequency component in load torque is eliminated, and the control performance of the system is improved more effectively. This paper proves the superiority of the new compound controller through comparison of simulation. results

Reduced-Order Observer Based Sliding Mode Control for a Quad-Rotor Helicopter

2016 ◽  
Vol 28 (3) ◽  
pp. 304-313 ◽  
Author(s):  
Reesa Akbar ◽  
◽  
Bambang Sumantri ◽  
Hitoshi Katayama ◽  
Shigenori Sano ◽  
...  
Keyword(s):  
Tracking Control ◽  
Closed Loop ◽  
Sliding Mode ◽  
Observer Design ◽  
Control Performance ◽  
Reduced Order ◽  
Reduced Order Observer ◽  
Euler Model ◽  
Sampled Measurements ◽  
Observation Noise

[abstFig src='/00280003/05.jpg' width=""230"" text='Quadcopter for repeated control verification' ] The reduced-order observer design we present estimates the velocity states of a quadrotor helicopter, or quadcopter, based on sampled measurements of position and attitude states. This observer is based on the forward-differentiation Euler model. The observer is robust enough against observation noise that the gain of a closed-loop controller is high enough to improve control performance. A sliding-mode controller stabilizes and implements quadcopter tracking control effectively, as is verified experimentally when compared to a conventional backward-difference method.

Disturbance observer based dynamic surface flight control for an uncertain aircraft

2017 ◽  
Vol 232 (4) ◽  
pp. 729-744 ◽  
Author(s):  
Jianjun Ma ◽  
Peng Li ◽  
Zhiqiang Zheng
Keyword(s):  
Flight Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Dynamic Surface ◽  
Nonlinear Disturbance Observer ◽  
Actuator Dynamics ◽  
Highly Nonlinear ◽  
Nonlinear Disturbance

To handle the flight control problem of an uncertain aircraft with highly nonlinear characteristics, internal uncertainties and external disturbances, an adaptive dynamic surface controller based on nonlinear disturbance observer is designed in this paper. A novel nonhomogeneous nonlinear disturbance observer is designed to approximate the uncertainties and disturbances, which can exactly estimate the disturbances in finite time. Dynamic surface control is utilized to avoid the explosion of complexity in traditional backstepping design. Through Lyapunov synthesis, the closed-loop control system is demonstrated to be semi-globally uniformly ultimately bounded and the tracking error converges to a small neighborhood of origin. Besides, actuator dynamics are taken into account, and the controller for actuator dynamics with consideration of limitation is developed based on sliding-mode control theory. The effectiveness of the proposed control is shown by simulation experiments.

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