倾转三旋翼垂直起降无人机悬停姿态控制

Hovering Attitude Control of Tilt Rri-rotor VTOL Aircraft

针对一种倾转三旋翼垂直起降(VTOL)飞行器在悬停状态下的姿态控制问题,设计了一种基于STM32系列微控制器的飞行控制系统。采用十轴组合惯性导航模块实时采集载机平台姿态信息,并结合基于四元数的互补滤波算法进行姿态信息解算。针对无人机姿态控制实时性和精度要求高的特点,采用串级PID控制算法对载机进行悬停状态下的姿态控制。实验结果表明:串级PID控制算法在悬停状态下能够对倾转三旋翼垂直起降飞行器进行快速、稳定、准确的姿态控制,并具有一定的鲁棒性。在横滚角的内环采用PD控制(Kp为8.371,Kd为3.015),外环采用PD控制(Kp为5.1,Kd为1.15);俯仰角的内环采用PD控制(Kp为3.137,Kd为1.6),外环采用PID控制(Kp为3.43,Ki为0.003,Kd为3.97);偏航角采用PI控制(Kp为9.30,Ki为0.11)时,其悬停状态下具有最优姿态控制效果。研究结果对倾转三旋翼垂直起降飞行器飞行控制的后续研究具有指导作用。

Aiming to the control of a tilt tri-rotor vertical take-off and landing(VTOL)aircraft,and the flight control system based on STM32 microprocessor was designed.Ten axes inertial navigation module was used to collect the real time position data and satellite navigation data of the carrier,and the attitude and location information was calculated by using fusion algorithm based on quaternion.Cascade PID control system was adopted,aiming at the real-time and high-accuracy feature of attitude control of UAV.Aiming at the unstable problem in the tilt tri-rotor VTOL aircraft,a PID controller with incomplete derivative was proposed.The controller adding a first-order inertial link in the derivative can reduce the negative effect of external interference on the system.Finally,the verify flight was carried out to test the pitch,yaw and roll motions of the aircraft.The results demonstrated that cascade PID controller with incomplete derivative can control the attitude of the tilt tri-rotor VTOL aircraft quickly,stably and accurately in helicopter mode,which had good robustness.In addition,cascade PID controller with incomplete derivative can reduce the difficulty of parameter tuning.The control system had a good performance with the setting of roll angle(inner ring K p was 8.371,K d was 3.015 and outer ring K p was 5.1,K d was 1.15),pitch angle(inner ring K p was 3.137,K d was 1.6 and outer ring K p was 3.43,K i was 0.003,K d was 3.97),yaw angle(K p was 9.30 and K i was 0.11).And the controller designed could meet the performance requirements of the control system.It provided guidance for the follow-up study on flight control of the tilt tri-rotor VTOL aircraft.