飞行器抗饱和鲁棒自适应非线性模型预测控制

摘要

针对巡航飞行器同时存在较大外部干扰和模型参数不确定性时自适应预测控制性能下降的问题,设计了带有模糊干扰观测器(fuzzy disturbance observer,FDO)补偿的鲁棒自适应非线性模型预测控制(robust adaptive nonlinear model predictive control,RANMPC)方法(简记为FDO-RANMPC方法).首先,利用具有未知参数限制条件的递推最小二乘方法在线辨识模型参数;其次,利用模糊干扰观测器输出值抵消幅值较大的复合干扰,再利用Tube鲁棒预测控制策略设计了飞行器底层姿态系统具有稳定保障的FDO-RANMPC控制器;最后,在考虑复合不确定性情况下对指令姿态角跟踪的仿真中验证了控制器的有效性及其渐进稳定性.%Aiming at the performance of the adaptive nonlinear model predictive flight controller degraded greatly when big external disturbance and model parameter uncertainties exist simultaneously,a robust adaptive nonlinear predictive controller with fuzzy disturbance observer compensation-robust adaptive nonlinear model predictive control (FDO-RANMPC) is proposed.Firstly,a recursive least squares method with restrictions on unknown parameters is employed for online identification of model parameters;Secondly,by using FDO output value to compensate and eliminate the larger composite disturbance,and by using Tube-RMPC control strategy,a FDO-RANMPC flight controller with guaranteed stability is developed;Finally,simulation results for attitude command tracking in the presence of composite disturbance demonstrate the applicability and the asymptotic stability of the designed controller.