不确定参数摄动的高超声速飞行器滑模控制

Sliding Mode Control for Hypersonic Vehicles with Uncertain Parameters Perturbation

针对系统内不确定性参数摄动的高超声速飞行器(Hypersonic Vehicles,HV)模型,考虑到传统气动系数简化模型无法真实反映飞行器的气动特性和高超声速下某些不确定性参数摄动的问题,提出了一种改进的气动系数模型,利用改进模型得到准确的气动系数参数,设计了一种基于某些不确定参数的模糊函数逼近的高超声速飞行器滑模控制器。应用模糊函数的强大函数逼近能力对不确定参数进行逼近,应用非线性最小二乘法对改进的气动系数模型进行参数辨识,并与滑模变结构控制结合,提高了系统的鲁棒性,并实现了对系统指令的稳定跟踪控制。仿真结果表明,飞行器在加入速度阶跃指令和高度阶跃指令后,系统能够保持稳定性,并对不确定性参数具有很强的鲁棒性。

For the hypersonic vehicle(HV)model with perturbation of uncertain parameters in the system,the traditional simplified model of aerodynamic coefficients of HV can not truly reflect the aerodynamic characteristics of aircraft and the perturbation of some uncertain parameters under hypersonic conditions.An improved aerodynamic coefficient model of HV has been proposed to obtain accurate aerodynamic coefficient parameters and designed a hypersonic vehicle sliding mode controller based on fuzzy function approximatior.The strong approximation ability of fuzzy function can approximate uncertain parameters,andthe above method is combined with sliding mode variable structure control to improve the robustness of the system and realize the stable tracking control of the system instructions.The simulation results show that the system can maintain stability after adding speed step instructions and altitude step instructions,and has strong robustness to uncertain parameters.