输入有约束时的飞翼布局无人机姿态控制

针对大展弦比飞翼布局无人机的刚体运动与弹性运动耦合动力学模型,研究了输入有约束时的无人机姿态控制问题,提出了一种采用扩张状态观测器的反步滑模控制方法.首先,采用扩张状态观测器实时估计气动弹性模态和外界未知干扰的影响,并引入跟踪微分器避免了控制律中项数膨胀问题.然后,针对飞翼布局无人机多操纵面的配置和输入约束,给出了基于LMI的在线舵面分配算法.最后,针对指令滤波和输入约束情况下控制指令的滞后问题,设计了辅助补偿器对控制指令进行补偿.根据Lyapunov稳定性理论证明了该控制方法能够保证姿态跟踪误差收敛至有界,仿真表明存在复合干扰和输入约束时该方法具有良好的姿态跟踪性能.

Attitude control for fly wing unmanned aerial vehicle with input constraints

Considering the coupling between the rigid motion and the elastic motion in the dynamic model of an unmanned aerial vehicle with high-aspect-ratio fly wing configuration, we investigate its attitude control under input constraints, and propose a backstepping sliding-mode control method by employing the extended state observer. The extended state observer estimates effects of the aeroelastic mode and unknown disturbance in realtime. A tracking differentiator is introduced to alleviate the term explosion in the control law. According to the allocation of multiple control surfaces in the aerial vehicle with high-aspect-ratio fly wing configuration and the input constraints, we put forward an online allocation algorithm for the allocation of control surfaces, based on the linear-matrix-inequality (LMI). An auxiliary compensator is applied to provide compensation for the control command with time-delay due to the filter and input constraints. Applying Lyapunov stability theorem, we prove that the attitude tracking error will converge to a bounded value. Simulation results show that good performances in attitude tracking control are achieved when disturbances and constraints exist.