Robust adaptive output‐feedback control for a class of nonlinear systems with time‐varying actuator faults

Abstract

A robust adaptive output-feedback control scheme is proposed for a class of nonlinear systems with unknown time-varying actuator faults. Additional unmodelled terms in the actuator fault model are considered. A new linearly parameterized model is proposed. The boundedness of all the closed-loop signals is established. The desired control performance of the closed-loop system is guaranteed by appropriately choosing the design parameters. The properties of the proposed control algorithm are demonstrated by two simulation examples.

Adaptive failure compensation of hysteretic actuators for a class of nonlinear systems via output feedback

“…An actuator failure is an eventuality that may lead to system undesirable behavior or even instability, causing catastrophic consequences. Recently, there has been a great interest in developing control schemes that are capable of handling such situations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], among which the adaptive control approach [4] possesses some prominent advantages such as only one controller is needed to accommodate system dynamics changes caused by unknown parameters and actuator failures; the knowledge of actuator failure parameters, time, pattern, and the explicit failure detection are not necessarily to be known; and with actuation redundancy, the control objectives are still achievable even if failures of some actuators take place during their operation.…”

“…More recently, the research has been focused on the following three aspects: (i) to extend the approach by Tao et al [4] to more general classes of nonlinear systems and more applications. In [10] and [11], adaptive output feedback actuator failure compensation schemes were proposed for a class of nonlinear systems in which all the nonlinear terms are either the functions of output signal or restricted by the bounding functions of output signal. In [12], the method was applied to address the adaptive output feedback failure compensation problem for the Twin Otter aircraft model; (ii) to design adaptive actuator failure compensation control for uncertain nonlinear systems so that the transient performance of the tracking error can be guaranteed on OE0; 1/ such as shown in [13], where an adaptive controller design scheme was proposed based on a prescribed performance bound [18], which characterizes the convergence rate and maximum overshoot of the tracking error; and (iii) to investigate the adaptive failure compensation control for some specific actuators such as that in [19], where a smooth adaptive state feedback control law was designed to compensate for the failure of the actuators whose nonlinearities can be characterized by backlash-like hysteresis.…”

“…It should be emphasized that the schemes proposed by Zhang et al [11] and Cai et al [19] can improve L 2 tracking performance either on the interval t q 0 ; 1 with t q 0 the instant at which the last failure takes place or in truncated form before the first failure takes place and therefore have less engineering significance. While in [13], although a prescribed tracking performance is achievable, a more complex control law is needed with the introduction of the output error transformation [18].…”

Zero-error tracking control of uncertain nonlinear systems in the presence of actuator hysteresis

“…Here, attention is focused on the design of continuous adaptive controller such that the dynamics of the tracking error is asymptotically stable. The backstepping technique (Chen & Li, 2008;Chen & Jiao, 2010;Chen, Jiao, Li, & Li, 2010aChen, Li, & Jiao, 2013;Kristic, Kanellakopoulos, & Kokotovic, 1995;Zhang, Xu, & Chu, 2010a, Zhang, Xu, Guo, & Chu, 2010b, Zhang, Xu, & Shen, 2010cZhang, Lu, & Xu, 2012) is used to design the compensation controller, while the Nussbaum gain approach (Chen & Zhang, 2010;Mudgett & Morse, 1985;Nussbaum, 1983;Ryan, 1994;Ye & Jiang, 1998;Zhang, Xu, & Wang, 2011) is employed to deal with the unknown control gain sign. More specially, the novelties of our results are listed as follows:…”

An alternative scheme for adaptive backstepping control

“…In the subsequent two years, this approach was used to develop output-feedback controllers [4,5] in order to improve the output-feedback schemes with overparametrization in [6,7]. Recently, the tuning functions method has been extended to many control communities such as robust adaptive control [8,9,10], adaptive control with partial overparametrization [11], decentralized adaptive control [12,13,14], approximation-based adaptive control [15,16], nonlinear systems with actuator nonlinearity [17], nonlinear time-delay systems [18], actuator failure compensation [19,20], etc. In this paper, we will present a novel design approach to solve the overparametrization problem.…”