Adaptive asymptotic tracking control of uncertain nonlinear systems with input quantization and actuator faults

This paper studies the problem of adaptive tracking control for a class of uncertain nonlinear systems with input quantization, external disturbances and actuator faults. It is assumed that the upper bounds of disturbances and the time varying stuck faults, are unknown. Firstly, an intermediate control law is designed by a modified adaptive backstepping design procedure, where a damping term with the estimate of unknown bounds and a positive time-varying integral function are introduced in the intermediate control law. Then, a novel smooth function is introduced in the control law to eliminate the effect of quantization based on the intermediate control law constructed in the first step. It is shown that all the closed-loop signals are bounded and the output tracking error converges to zero asymptotically in spite of input quantization, disturbances and possibly infinite number of faults. Finally, simulation results demonstrate the efficiency of the proposed algorithm. (C) 2016 Elsevier Ltd. All rights reserved.

本文研究了一类具有输入量化、外部干扰和执行器故障的不确定非线性系统的自适应跟踪控制问题。假定干扰以及时变卡死故障的上界是未知的。首先，通过一种改进的自适应反推设计方法设计了一个中间控制律，其中在中间控制律中引入了一个带有未知界估计的阻尼项以及一个正的时变积分函数。然后，基于第一步构建的中间控制律，在控制律中引入了一种新的光滑函数以消除量化的影响。结果表明，尽管存在输入量化、干扰以及可能数量无限的故障，所有闭环信号都是有界的，并且输出跟踪误差渐近收敛到零。最后，仿真结果证明了所提算法的有效性。© 2016爱思唯尔有限公司。保留所有权利。