基于改进视线法的欠驱动无人艇路径跟踪

Path following of underactuated unmanned surface vehicles based on the improved line-of-sight guidance strategy

针对水面无人艇执行高机动性任务时速度随时可能改变,从而影响控制精度,如目标包围、目标检测。本文提出基于自适应双曲正切视线法控制系统,通过自适应参数减小水面无人艇纵向速度改变对视线法的影响,采用tanh函数修正期望艏向曲线平缓度。仿真结果表明:虽然基于自适应双曲正切视线法和视线法均能在恒定速度和曲率变化范围内很好的收敛,但是在速度和曲率的范围会发生变化的情况下,基于自适应双曲正切视线法依旧能够保持良好的控制精度,视线法精度受损较大,其中速度震荡时间,横侧偏差超调明显变大。通过外场试验证明了基于自适应双曲正切视线法在随机环境干扰下,基于自适应双曲正切视线法具有较好的鲁棒性,且其能够在高速航行的情况下仍然具备较好跟踪精度。

For a high-maneuverability task,the velocity of unmanned surface vehicles(USVs)may change at any time to affect control accuracy,such as target enclosure and target detection.In this paper,the adaptive tanh line-of-sight(ATLOS)guidance strategy is proposed to reduce the impact of the change of USVs′longitudinal velocity on the LOS algorithm through adaptive parameters,and the Tanh function is used to correct the smoothness of the desired heading angle.Simulation results show that ATLOS and LOS converge well within the range of constant velocity and curvature.However,under the circumstance that the range of velocity and curvature will change,ATLOS can still maintain good control accuracy,and the LOS precision is greatly damaged,in which the velocity oscillation time and lateral deviation overshooting clearly increase.Finally,through field experiments,it is proven that ATLOS has better robustness under random environmental disturbances and still have a good tracking accuracy in the case of high-speed navigation.