带有指令滤波器的模糊反步自适应控制

摘要

A fuzzy backstepping adaptive controller with a command filter was designed for a fixed-wing aircraft to overcome the problems of the restricted state and actuator's physical characteristics during the flight control process.First,the MIMO strict feedback system with error terms was developed.Secondly,a fuzzy system was developed to approach the error terms of the subsystem online,and the virtual control law was designed for each subsystem based on Backstepping method.Thirdly,considering the state constraints and the physical characteristics of actuators (including the constraints of amplitude and rate),a command filter with constraints on amplitude,rate and bandwidth was introduced into the designed virtual control law to compensate for the filter error term.Finally,Lyapunov stability theorem was used to prove that the closed-loop system is guaranteed to be bounded,and the tracking error converges exponentially to a small neighborhood around zero.The simulation results show that the designed controller has strong stability and robustness.%针对固定翼飞行器在飞行控制过程中存在的状态受限以及执行器物理特性限制等问题,提出了一种带有指令滤波器的反步模糊自适应控制器.首先,建立带有误差项的MIMO严反馈系统;其次,建立模糊系统在线逼近子系统误差项,基于Backstepping法对每一个子系统设计虚拟控制律;再次,考虑状态受限和执行器的物理特性(包括幅值和速率受限),将设计的虚拟控制律通过引入幅值、速率和带宽限制的指令滤波器,对滤波误差项进行补偿;最后,运用Lyapunov稳定性定理证明了闭环系统有界且跟踪误差指数收敛于零的一个邻域内.仿真结果表明,设计的控制器具有很强的稳定性和鲁棒性.