基于自适应视线法的无人机三维航迹跟踪方法

During the process of 3D path following of Unmanned Aerial Vehicles (UAVs), there exist the issues of big following error and slow rate of convergence when the reference path is switched. An Adaptive-Line-of-Sight (ALOS)-based following control method is proposed. To improve the accuracy of path following when the reference path is switched, an adaptive acceptance circle strategy is customized by setting the different acceptance circles automatically according to the angle between two reference path segments. An adaptive lookahead distance strategy based on the feedback of horizontal and vertical following errors is proposed by automatically setting the target direction in real time according to the following errors, so as to guide the UAV converging to the reference path quickly and steadily. A state feedback following control law based on the ALOS method, in which is introduced the adaptive acceptance circle strategy and adaptive lookahead distance strategy, is designed to guarantee that the UAV will track the reference path stably. The simulation results illustrate that the method proposed can obtain smaller following error and faster rate of convergence compared to the classic line-of-sight methods based on fixed acceptance circle and look ahead distance. Furthermore, a comparison with the nonlinear guidance law demonstrates better following accuracy and convergence speed of the proposed method.