Optimal Tracking Control for Nonstrict-Feedback Nonlinear Systems

Authors: yuanbo  su
qihe  shan
Venue: IEEE_org_ICIST_2024_Conference
Published: 2024-08-15 09:42:12

Abstract: This paper investigates the optimized tracking control problem for nonlinear single-input-single-output systems in nonstrict-feedback form. An intelligent approximation-based optimized backstepping control strategy is developed using reinforcement learning. An improved variable separation method is presented to address the algebraic loop issue arising from the implementation of virtual optimized controls. The designed actual optimized controller ensures that the system’s output converge to a small neighborhood of the reference signal and all the signals in closed-loop systems are semiglobally ultimately uniformly bounded.

Main paper: 
 school of automation engineering university of electronic science and technology of china: 
 Chengdu, China tieshanli@126.comAbstract-This paper investigates the optimized tracking control problem for nonlinear single-input-single-output systems in nonstrict-feedback form. An intelligent approximation-based optimized backstepping control strategy is developed using reinforcement learning. An improved variable separation method is presented to address the algebraic loop issue arising from the implementation of virtual optimized controls. The designed actual optimized controller ensures that the system's output converge to a small neighborhood of the reference signal and all the signals in closed-loop systems are semiglobally ultimately uniformly bounded.Index Terms-tracking control, nonlinear systems, nonstrictfeedback form, optimized backsteppingOptimized backstepping consensus control for nonlinear systems has been widely investigated owing to its engineering applications. The goal of optimized control is to design reinforcement learning-based controller which makes system's output to agree on a desired signal, and realizes a tradeoff between the control performance and the control cost. Nevertheless, the considered system models are the strict-feedback form, which can be expressed asẊi =X i+1 + F i ( Xi ) (1) Ẋn =U + F n (X n ) (2) Y =X 1 (3)where, for i = 1, 2, ..., n, Xi = [X 1 , . . . , X i ] T , U and Y are the state vector, the control input, the output of the system, respectively. such as robot systems and electrical systems. As for the reinforcement learning-based optimized backstepping control of nonlinear systems in nonstrict-feedback form, the proposed virtual optimized local controls can include whole states of controlled systems since the nonlinearity term F i (•) can be the ones with all states, which can be expressed asF i (X i ), where X i = [X 1 , . . . , X n ]T . This will lead to the problem of algebraic loop, which motivates our work.To design the optimal controller for nonstrict-feedback nonlinear systems, where system's dynamic includes the nonlinear functions of whole state variables, the algebraic loop problem must be solved. An improved variable separation technique is proposed by establishing a new variable separation inequality and utilizing the structure feature of fuzzy logic systems. Specifically, the designed virtual optimal controllers for systems are independent of the whole state variables in this paper.This paper has developed an adaptive optimal tracking control method for nonstrict-feedback nonlinear systems. A new variable separation method has been proposed to address the problem of algebraic loop in the implementation of virtual optimal controllers. It can be proven that the designed actual optimized controller ensures that the systems output converge to a small neighborhood of the reference signal and all the signals in closed-loop systems are semiglobally ultimately uniformly bounded. 
 
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Reviews: review: title: title: The author is advised to optimise this paper
main_review: main_review: This paper proposes an intelligent approximation-based optimized backstepping control strategy based on  reinforcement learning and presents a variable separation method. To address the problem of algebraic loop in the implementation of virtual optimal controllers, there is a new variable separation method. It is recommended that the authors give a quantitative analysis.
title: title: reject
main_review: main_review: This paper investigates the optimized tracking control problem for nonlinear single-input-single-output systems in nonstrict-feedback form. Unfortunately, we regret to inform you that due to insufficient innovation in your paper, it cannot be published at this conference.
title: title: Lack of innovation
main_review: main_review: This article lacks innovation. And the writing structure of the article is not clear.