非匹配扰动干扰下的无人直升机轨迹跟踪控制

Robust trajectory tracking control for unmanned helicopter with mismatched disturbances

针对小型无人直升机在飞行过程中容易受到非匹配扰动影响的特点,本文设计了一种基于新型滑模控制方法的轨迹跟踪控制器.首先,建立了无人直升机系统的非线性数学模型,并对该模型进行近似反馈线性化处理,同时将模型分为位置和偏航两个子系统;然后,利用扩展扰动观测器对复合扰动以及非匹配扰动的各阶导数的估计值,设计新型时变滑模面,得到滑模控制律,并给出了控制系统的稳定性分析;最后,仿真结果验证了控制方法的有效性和优越性.该新型滑模控制方法的优越性主要体现在:对非匹配扰动具有较强的鲁棒性,以及能有效地抑制抖振现象.

We investigate the robust trajectory tracking controller based on extended disturbance observer（EDO） and sliding mode control algorithm for small-scale unmanned helicopters in the presence of mismatched disturbances. First,a nonlinear mathematical model of unmanned helicopter is presented, to which the approximate linearization technique is applied for partitioning it into two interconnected subsystems： position subsystem and yaw subsystem. Then, by integrating the mismatched disturbances and their derivatives into the new time-varying sliding- mode surface, we develop a novel sliding-mode controller for the helicopter system. Moreover, the stability analysis of the closed-loop system is given.Finally, some comparative simulation results are presented to illustrate the effectiveness and superiority of the proposed control method for unmanned helicopters. This novel sliding-mode controller has two key advantages： insensitivity to mismatched disturbances and suppression of chattering phenomenon.