基于扰动观测器的多旋翼无人机机载云台模糊自适应跟踪控制

Fuzzy self-adjusting tracking control based on disturbance observer for airborne platform mounted on multi-rotor unmanned aerial vehicle

为了补偿多旋翼无人机机载云台的扰动,实现机载云台的稳定跟踪控制,提出基于改进扰动观测器的模糊自适应跟踪控制方法.在原有扰动观测器结构的反馈回路中引入一个补偿控制,构建基于速度信号的改进型扰动观测器结构,分析该结构的补偿扰动能力和鲁棒性;利用模糊系统的逼近性质和李雅普诺夫稳定性原理,设计相应的模糊自适应跟踪控制结构,证明了该控制结构的稳定性.飞行实验表明,应用该控制方法后,视轴稳定误差的均方值小于0.02°,跟踪给定位置信号的跟踪误差小于0.08°,完全能够满足多旋翼无人机机载云台的稳定跟踪控制.引入补偿控制后的扰动观测器补偿扰动能力明显提高,提出的控制方法具有较高的稳定跟踪精度.

A scheme of fuzzy self-adjusting tracking control based on an improved disturbance observer（DOB）was proposed in order to compensate disturbance and accomplish the stabilized tracking control for airborne platform mounted on multi-rotor unmanned aerial vehicle.A compensated control was introduced into feedback loop which is in the structure of original disturbance observer.An improved disturbance observer was constructed based on velocity signals. The ability of disturbance compensation and robustness were analyzed.A fuzzy self-adjusting tracking control structure was designed according to the approaching property of fuzzy system and Lyapunov stability theory.The stability of the tracking control structure was proved.The flight experiment results showed that the mean square error of line of sight was below 0.02°and the error of tracking reference position was less than 0.08°after applying the proposed scheme.Results demonstrate that the proposed scheme can completely satisfy the stabilized tracking control demand of airborne platform.The disturbance rejected ability was significantly improved after introducing the compensated control.The proposed control method possessed upper stabilized tracking accuracy.