飞翼布局无人机反步L_2增益纵向着陆鲁棒控制

Backstepping L_2 gain robust control of longitudinal landing of flying-wing UAV

针对存在干扰的飞翼布局无人机纵向着陆控制问题,提出一种基于super twisting滑模干扰观测器与跟踪微分器的反步L_2增益鲁棒控制方案.为解决反步控制虚拟控制量求导复杂的问题,设计了跟踪微分器对虚拟控制量进行求导,同时综合采用super twisting滑模干扰观测器和L_2增益鲁棒项增强了控制系统的鲁棒性.仿真结果表明,无人机高度、空速都跟踪上控制指令,垂直接地速度在允许的范围内,与传统的PID着陆控制方案相比具有更好的着陆控制性能.

For the longitudinal landing control problem of flying-wing UAV with unknown external disturbances, a backstepping L2 gain robust control scheme based on super twisting sliding mode disturbance observer and tracking differentiator is proposed. The tracking differentiator is introduced to calculate the derivative of virtual control law which is very difficult to evaluate with the traditional backstepping control. Super twisting sliding mode disturbance observer and L2 gain robust item are designed to increase the robustness of the control system. Simulation results show： the altitude and airspeed of UAV are tracked on control command, vertical ground speed is within the allowable range. Compared with traditional PID control scheme, the proposed control scheme has better automatical landing control performance.