非线性动态突变系统的多模型自适应执行器故障补偿设计

A Multiple-Model Based Adaptive Actuator Failure Compensation Scheme for Nonlinear Systems With Dynamic Mutations

本文针对因多重不确定执行器故障而引起系统动态突变的非线性系统,设计了一种基于多模型切换的自适应执行器故障补偿控制策略,以提高系统应对动态突变的能力,同时实现不确定执行器故障的快速精确补偿.针对执行器故障模式的不确定性问题,采用基于多模型的参数估计方法,设计了自适应控制器组;基于最优性能指标函数,提出了一种控制切换机制,以选择最佳的自适应控制器作为当前的控制器,从而实现期望的故障补偿控制.所设计的多模型自适应控制策略,可以保证所有闭环系统信号有界,且在出现有限数量的不确定性执行器故障情况下,系统输出渐近跟踪所选择的参考系统输出;同时,当系统中出现持续间歇性执行器故障时,此方法可以保证系统的输出跟踪误差是平均小的.最后,本文基于飞行器动力学模型,进行仿真研究,验证了所设计的自适应故障补偿策略的有效性.

In this paper,a multiple-model switching based adaptive failure compensation scheme is developed for feedback linearizable nonlinear systems with uncertain actuator failures and dynamic mutations,for fast and accurate actuator failure compensation.To deal with uncertain failure pattern conditions,multiple adaptive controllers are designed based on multiple model parameter estimation.A control switching mechanism is employed based on finding the minimal performance cost index for selecting the best controller for failure compensation.The designed multiple model adaptive control scheme can ensure that all closed-loop system signals are bounded and the system output asymptotically tracks the reference output in presence of finite number of uncertain actuator failures.Moreover,it can ensure the tracking error is small in the mean for persistent failures.Simulation results for an aircraft dynamic model are shown to verify the effectiveness of our designed control method.