风干扰下基于变船长比的无人水面艇路径跟踪方法

Path Following Method of Unmanned Surface Vehicle Based on Variable Ship Length Rate Under the Wind Interference

摘要:

针对无人水面艇在路径跟踪过程中易受风环境干扰的问题,建立了风环境下无人水面艇的运动数学模型,提出一种用于抵抗风干扰的直线路径跟踪方法;首先,基于视距导航原理,设计了跟踪期望航向角的PD控制器,通过融合路径方向,距离偏差及船长比等信息,实时调整左右两侧推进电机的控制电压,实现无人水面艇直线路径跟踪;然后,针对不同船长比对直线路径跟踪的影响,采用模糊控制方法,设计了以跟踪过程中的距离偏差和距离偏差变化率为输入,以船长比为输出的模糊控制模块,对船长比进行自适应调整,以提高控制器的抗风干扰性能;仿真结果表明,所提方法可减小风干扰作用下的跟踪静差,较之传统单纯PD控制方法,抵抗风干扰的能力得到提高。

Abstract:

In order to resist the wind interference that may occur when the Unmanned Surface Vehicle(USV) follows the straight path, the mathematical model of the USV in the wind environment is established and a straight path following method for resisting wind interference is presented. First,based on the principle of Line of Sight(LOS), the PD controller that follows the desired heading angel is designed, which can adjust the control voltage of the left and right propulsion motor timely,so that the USV can follow a straight path through fusing ship length rate,path orientation,distance error and other information.Then, according to the influence of ship length rate on straight path following, a fuzzy control module whose output is ship length rate and whose inputs are the distance error and the derivative of distance error is designed ,which is used to adjust ship length rate so as to improve the performance of resisting wind interference.The simulating experiments show that the proposed method can reduce the static following error under the wind interference.In comparison with the traditional PD method ,the ability to resist wind interference is improved.