高超声速飞行器模糊自适应动态面容错控制

Fuzzy Adaptive Dynamic Surface Fault-Tolerant Control for Hypersonic Vehicles

针对输入饱和下高超声速飞行器发生执行机构损伤故障并存在参数不确定的情况,提出了一种基于Nussbaum增益技术的模糊自适应动态面容错控制策略.对于飞行器的高度和速度子通道,分别设计了动态面和动态逆控制器.利用双曲正切函数逼近飞行器的输入饱和特性,并基于中值定理将其转化为控制输入的仿射形式.对于损伤故障和参数不确定导致的控制增益未知问题,通过引入Nussbaum增益技术既保证控制系统稳定,又可以避免控制器奇异问题.通过设计模糊自适应系统,在线逼近包含不确定参数与饱和逼近误差的未知函数项,且引入范数估计思想,使得每个模糊系统仅包含一个自适应参数,以减小计算量.稳定性分析证明了闭环控制系统的半全局一致最终有界性,仿真结果验证了该容错控制算法的有效性.

For the hypersonic vehicles with input saturation and suffering from actuator damage fault and parameteruncertainty,a fuzzy adaptive dynamic surface fault-tolerant control strategy based on Nussbaum gain technique wasproposed in this paper.For the altitude dynamics and velocity dynamics,the dynamic surface controller(DSC)anddynamic inversion controller were designed respectively.The hyperbolic tangent function was introduced to approximatethe saturation function,and then the mean-value theory was used to affine transformation of inputs.To handlethe unknown control gain resulting from damage fault and parameter uncertainty,the Nussbaum gain method wasemployed to ensure the stability of the control system and to overcome the possible singularity of the controllers.Additionally,the fuzzy adaptive strategy was adopted to approximate the unknown functions caused by uncertainparameters and saturation errors online.Moreover,the norm estimation method was utilized to decrease computationburden,where only one adaptive parameter was involved in each fuzzy system.The stability analysis verifiesthe semi-global uniformly ultimate boundedness of the closed-loop control system.The illustrative simulation demonstratesthe effectiveness of the fault-tolerant control method.