一种可倾斜六旋翼无人机容错控制方法

A fault tolerant control method of tiltable six-rotor unmanned aerial vehicle

常规六旋翼无人机在单个旋翼完全失效后,存在姿态与高度不完全可控的情况,此时采取降级控制策略会使无人机失去静态悬停能力.针对此问题,本文提出了一种可倾斜旋翼的容错控制方法,在经典旋翼结构布局的基础之上,将其中一个旋翼设计成可倾斜结构,通过倾斜角度的改变与控制分配重构,无人机在任意单个旋翼完全失效后均能保持力与力矩的平衡.利用线性规划方法得到无人机的可达力矩集,同时对电机饱和度进行分析,确定了不同旋翼失效后的最优倾斜角.搭建飞行测试平台进行对比验证,实验结果表明,本文提出的方法具有良好的容错效果与鲁棒性,能够保证六旋翼无人机在故障后的稳定飞行与平稳降落.

The attitude and altitude of conventional six-rotor unmanned aerial vehicle(six-rotor UAV)cannot be fully controlled under the failures of one of its rotors.Adopting a degraded control strategy will make the UAV lose the ability of static hovering.Aiming at this problem,a fault tolerant control method for tiltable rotors is proposed.Based on the classic rotor structure layout,one of the rotors is designed as tiltable structure.Force and moment can be balanced after any rotor failure by the change of the tilt angle and the control allocation.The attainable moment set of six-rotor UAV is obtained by using the linear programming method,and the motor saturation is analyzed at the same time to determine the optimal tilt angle after different rotor failures.A flight test platform is built for comparison and verification.The experimental results show that the proposed method has good fault tolerance and robustness,and can guarantee the stable flight and landing of the six-rotor UAV under fault conditions.