风扰动下固定翼无人机指令滤波反步着陆控制

Command Filtered Backstepping Landing Control of Fixed-Wing Unmanned Aerial Vehicle Considering Wind Disturbance

针对存在模型不确定性及风干扰时的固定翼无人机纵向着陆控制问题,提出一种基于有限时间扩张状态观测器的指令滤波反步控制方案。首先建立了风干扰下的无人机动力学模型。然后将无人机的高度和空速分开控制,利用反步法求取控制信号,并设计有限时间扩张状态观测器对复合干扰进行估计;同时,引入指令滤波器以避免传统反步法中的“微分爆炸”问题。最后通过Lyapunov理论证明了系统的稳定性。仿真结果表明,所提出的控制方案能够实现对空速指令及高度指令的稳定跟踪,对模型不确定性及风干扰具有较好的鲁棒性。

A command filtered backstepping control scheme based on the finite-time extended state observer is proposed for the longitudinal landing control problem of fixed-wing unmanned aerial vehicle(UAV) with model uncertainties and wind disturbances. Firstly, the dynamic model of UAV under wind disturbances was established. Then the altitude and airspeed of UAV were controlled separately, the control signals were obtained by using the backstepping method, and the finite-time extended state observer was designed to estimate the disturbances;Meanwhile, the command filters were introduced to avoid the“explosion of complexity”problem of the traditional backstepping control method. Finally, the stability of the system was proven through Lyapunov theory. Simulation results show that the proposed control method can guarantee the stably tracking of the altitude and airspeed reference signals, and has good robustness to model uncertainties and wind disturbances.