执行器有故障的多输入单输出系统的自适应输出反馈控制

Adaptive output feedback control for multi-input single-output systems with actuator failures

中文关键词  后推控制  未建模动态  输出反馈  变能量函数

英文关键词  backstepping control  unmodeled dynamics  output feedback  changing supply function

中文摘要

      对一类控制增益符号未知且执行器有故障的输出反馈多输入单输出非线性系统, 提出了一种后推容错控 制方案. 该方案在系统状态不可量测的情况下, 利用Nussbaum函数处理符号未知的常数增益, 并通过构造K-滤波器 来估计了系统不可量测的状态. 在容错控制器设计过程中, 引入变能量函数来处理利用虚拟控制律所无法抵消的 部分. 与现有研究成果相比, 放宽了未知增益需要上下界均为已知的假设条件. 最后, 通过选取合适的李雅普诺夫 函数, 证明了闭环系统所有信号半全局一致终结有界, 且跟踪误差收敛到原点的一个小邻域内. 仿真结果表明了所 提控制方法的有效性.

英文摘要

      We proposed a fault-tolerant control scheme based on backstepping for a class of multi-input single-output (MISO) nonlinear output feedback systems with unknown control gain signs and actuator failures. Under the conditions that the states of the systems are unmeasured, we employ Nussbaum function and K-filters to deal with the constant gains with unknown signs and estimate the unavailable states, respectively. In designing the fault tolerant controller, the parts that the virtual control laws cannot counteract are disposed by introducing the changing supply function. Compared with the existing research results, the proposed approach relaxes the assumed restrictions that the upper and lower bounds of the unknown gains should be known. By choosing appropriate Lyapunov function, we show the closed-loop control system is semi-globally uniformly ultimately bounded, with the tracking error converging to a small neighborhood of the origin. Simulation results demonstrate the effectiveness of the proposed approach.