参考航速时变的无人船轨迹跟踪控制方法

USV trajectory tracking control method with time-varying reference speed

针对参考航速时变的无人船(unmanned surface vehicle,USV)曲线轨迹跟踪控制问题,提出基于模型预测控制(model predictive control,MPC)的USV轨迹跟踪控制方法。建立USV三自由度运动模型,在已知期望轨迹的前提下,构建Serret-Frenet坐标系,利用投影法找到期望点,引入时变的期望参考速度函数,在控制时域内构造出了时变的参考量序列。针对轨迹跟踪控制需求,结合USV位置、投影点位置、期望点位置、合速度方向及期望方向设计了轨迹跟踪控制目标函数,考虑USV动力机构约束,设计USV时变参考量的轨迹跟踪模型预测控制器。仿真结果表明,设计的轨迹跟踪控制器对参考位置和参考航速均具有良好的控制效果。

Aiming at the time-varying control of ship speed in current USV trajectory tracking,a USV trajectory tracking control method based on model predictive control algorithm is proposed.The UsV three-degree-of-freedom motion model is established,the Serret-Frenet coordinate system is constructed on the premise of known desired trajectory,the desired point is found by projection method,the time-varying expected reference speed function is introduced and the time-varying reference sequence is constructed in the control time domain.Aiming at the requirements of trajectory tracking control,the trajectory tracking control objective function is designed combining USV position,projection point position,desired point position,closing speed direction and desired direction.Considering the constraints of USV power mechanism,a trajectory tracking model predictive controller with time-varying USV reference is designed.The simulation results show that the designed trajectory tracking controller has good control effect on reference position and reference speed.