倾转三旋翼无人机控制设计与飞行实验

Control design and flight experiment of tilt tri-rotor unmanned aerial vehicle

针对倾转三旋翼无人机的飞行控制问题,本文围绕控制分配算法、控制权重设计和模态转换策略3个方面开展研究.首先,分析飞行控制原理,构建模态转换飞行控制框架;其次,为提高控制分配鲁棒性,设计串级解耦控制分配算法并提出两种控制分配参数修正方法;为实现稳定的模态转换飞行,引入可达力矩集设计控制权重,并提出基于时间和倾转角度的模态转换策略;最后,分别开展旋翼模态与模态转换飞行试验,验证了控制方法的有效性.试验结果表明:引入参数修正的串级解耦控制分配算法可有效提高控制分配鲁棒性,并改善姿态控制性能,基于设计的控制权重与模态转换策略可确保模态转换飞行的安全性、稳定性.

Concerning the flight control problem of the tilt tri-rotor unmanned aerial vehicle,this paper designs the control allocation algorithm,the weight coefficient,and the mode transition strategy.Firstly,the principle of flight control in different modes is analyzed,and the complete flight control framework of mode transition is proposed accordingly.Secondly,a cascaded-coupling control allocation algorithm and two kinds of parameter modification methods are developed to improve the robustness of the control allocation.Thirdly,the attainable moment set is applied to design the control weight coefficient,and the mode transition strategy that depends on time and tilting angle is proposed for achieving a stable mode transition flight.Finally,the flight experiments in the helicopter mode and the transition mode are conducted,respectively,which corroborate the effectiveness of the proposed methods.The results show that the robustness of control allocation and the performance of attitude control are improved by using the cascade-decoupling control allocation algorithm;the safety and stability of the mode transition flight are guaranteed by the control weight coefficient and mode transition strategy.