scholarly journals Adaptive anti-disturbance control for a class of unknown pure feedback switched nonlinear systems

Author(s):  
Longsheng Chen

Abstract In this study, an adaptive anti-disturbance control scheme is investigated for a class of unknown pure feedback switched nonlinear systems subjected to immeasurable states and external disturbances. Radial basis function neural networks (RBFNNs) are employed to identify the switched unknown nonlinearities, and a Butterworth low-pass filter is adopted to remove the algebraic loop problem. Subsequently, a novel switched neural state observer and a novel switched disturbance are presented via the coupled design method to estimate the immeasurable states and compounded disturbances. Then, an improved adaptive control strategy for the studied problem is designed with the help of a filtering method to eliminate the “explosion of complexity” problem, and certain compensating signals are set up to compensate for the filter errors, where switched updated laws are constructed to lessen the conservativeness caused by adoption of a common updated law for all subsystems. By utilizing the Lyapunov stability theorem, the developed control scheme can guarantee that all signals in the closed-loop system are bounded under a class of switching signals with the average dwell time (ADT), while the tracking error can converge to a small neighbourhood of origin. Finally, simulation results are provided to demonstrate the effectiveness of the presented approach.

2020 ◽  
Vol 42 (13) ◽  
pp. 2482-2491
Author(s):  
Shan-Liang Zhu ◽  
De-Yu Duan ◽  
Lei Chu ◽  
Ming-Xin Wang ◽  
Yu-Qun Han ◽  
...  

In this paper, a multi-dimensional Taylor network (MTN)-based adaptive tracking control approach is proposed for a class of switched nonlinear systems with input nonlinearity. Firstly, the input nonlinearity is assumed to be bounded by a sector interval. Secondly, with the help of MTNs approximating the unknown nonlinear functions, a novel adaptive MTN control scheme has the advantages of low cost, simple structure and real time feature is developed via backstepping technique. It is shown that the tracking error finally converges to a small domain around the origin and all signals in the closed-loop system are bounded. Finally, two examples are given to demonstrate the effectiveness of the proposed control scheme.


2014 ◽  
Vol 492 ◽  
pp. 493-498
Author(s):  
Shuhei Shiina ◽  
Sidshchadhaa Aumted ◽  
Hiroshi Takami

The proposed optimal control on the basis of both current and voltage of the buck-converter is designed to be based on Inverse Linear Quadratic (ILQ) design method with the resonant low pass filter, which eliminates the disturbance by appended disturbance compensator. The designed scheme is composed of the state equation, an optimal ILQ solution, the ILQ servo-system with the disturbance elimination, the optimal basic gain, the optimal condition, the transfer functions and the disturbance compensator. Our results show the proposed strategy is the stability and robust control and has been made to improve ILQ control for the disturbance elimination of the output response, which guarantees the optimal gains on the basis of polynomial pole assignment.


Author(s):  
Kunal N. Tiwari ◽  
Parameswaran Krishnankutty

The purpose of this paper is to examine the performance of fuzzy controller applied to a dynamic positioning system of ship by numerical simulation. By definition, dynamic positioning system is computer controlled system which uses the active thrusters to automatically maintain the position and heading of the ship. The proposed control scheme consist of low pass filter in cascade with three proportional derivative type fuzzy controller with Mamdani type inference scheme. Feed-forward compensation decoupling scheme is employed to reduce coupling between sway and yaw. Robustness of control scheme is assessed for Cybership II in presence of wave disturbances.


1989 ◽  
Vol 111 (3) ◽  
pp. 353-358 ◽  
Author(s):  
Masayoshi Tomizuka ◽  
Tsu-Chin Tsao ◽  
Kok-Kia Chew

Repetitive control is formulated and analyzed in the discrete-time domain. Sufficiency conditions for the asymptotic convergence of a class of repetitive controllers are given. The “plug-in” repetitive controller is introduced and applied to track-following in a disk-file actuator system. Inter-sample ripples in the tracking error were present when the “plug-in” repetitive controller was installed. The performance is enhanced, however, when the zero-holding device is followed by a low-pass filter or replaced by a delayed first-order hold.


2013 ◽  
Vol 575-576 ◽  
pp. 293-296
Author(s):  
Qun Min Yan

in order to solve the problem of three-phase static inverter output waveform distortion, detailed analyzed of the voltage distortion caused by the deadband effect and the resulting harmonic components. The control method is proposed to set the deadband time combining with the voltage compensation, while in order to improve the inverter output, the converter output to design a trap filter and a low pass filter cascaded filtering circuit. Simulated analysis the entire system though Saber, using the digital chip TMS320F2812 to achieve appropriate compensation strategies, simulation results and experimental results have all proved the effectiveness of the design method.


2018 ◽  
Vol 138 (5) ◽  
pp. 384-391
Author(s):  
Masatoshi Suzuki ◽  
Kenichirou Ogawa ◽  
Fumi Moritsuka ◽  
Tetsu Shijo ◽  
Hiroaki Ishihara ◽  
...  

2021 ◽  
Vol 3 (2) ◽  
pp. 103
Author(s):  
Hendra J. Tarigan

A physical system, Low Pass Filter (LPF) RC Circuit, which serves as an impulse response and a square wave input signal are utilized to derive the continuous time convolution (convolution integrals). How to set up the limits of integration correctly and how the excitation source convolves with the impulse response are explained using a graphical type of solution. This in turn, help minimize the students’ misconceptions about the convolution integral. Further, the effect of varying the circuit elements on the shape of the convolution output plot is presented allowing students to see the connection between a convolution integral and a physical system. PSpice simulation and experiment results are incorporated and are compared with those of the analytical solution associated with the convolution integral.


Author(s):  
Xiao X. Dong ◽  
Jun Zhao

This paper is devoted to the problem of robust output tracking control for uncertain cascade switched nonlinear systems with external disturbances. A sufficient condition for the output tracking problem of switched systems to be solvable is given in terms of the average dwell-time scheme and linear matrix inequalities where no solvability of the output tracking control problem for all subsystems is assumed. The controllers are designed based on a variable structure control method in order to conquer the uncertainties. Simulations illustrate the effectiveness of the proposed robust tracking design method.


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