固定时间预测器下的欠驱动无人艇路径跟踪控制

Fixed-Time Predictor-Based Path Following Control of Unmanned Surface Vehicles

中文关键词  无人艇  固定时间控制  路径跟踪  视线法

英文关键词  underwater surface vehicle  fixed-time control  path following  line-of-sight guidance law

中文摘要

      无人艇是一类在水面自主移动的智能船艇, 具有无人自主, 航速高, 欠驱动的特点, 能应用到民用和军事的诸多领域. 针对欠驱动无人艇的路径跟踪问题, 本文在传统视线法制导律的基础上, 首次提出了一种新的固定时间收敛的预测器, 用于预测位置误差, 实现对干扰的估计和补偿. 与基于有限时间收敛的预测器的制导律相比, 固定时间预测器收敛时间不依赖于初始状态, 可以更快收敛. 此外, 为了保证跟踪控制器的有效收敛, 还设计了固定时间控制器, 将无人艇尾部的方向舵力矩作为控制器, 使无人艇航向角在固定时间收敛到期望艏向角. 最后通过仿真实验证明本文所提出的制导律和控制器能精确跟踪给定路径.

英文摘要

      Unmanned surface vehicles (USVs) is a kind of smart ship that moves autonomously on the water. It has the characteristics of automation, high speed and underactuation, and can be applied to both civil and military fields. This paper developed a new fixed-time convergence predictor based on the LOS(line-of-sight) guidance law for path following tasks of underactuated vehicles, to predict position error and estimate external disturbance. The convergence time of the fixed-time predictor does not depend on initial state and converge faster compared with the finite-time predictor-based guidance law. Besides, a fixed-time controller is designed to ensure effective convergence of tracking controller. It controls the steering torque, applying to the tail of the USV, which makes heading angle converge to the desired value in fixed-time. Finally, simulation experiments demonstrate that the proposed guidance law and controller can follow the given path accurately.