基于模糊控制的无人水面艇直线路径跟踪方法

Straight Path Tracking Method of an Unmanned Surface Vehicle Based on Fuzzy Control

摘要:

针对直流电机驱动固定双桨的无人水面艇,提出一种基于模糊控制的直线路径跟踪方法；利用无人水面艇到目标路径的垂直距离以及无人水面艇的实际航向与给定路径方向的差值来确定无人水面艇的当前状态,根据模糊推理的方法实时调整左右两侧推进电机的输入电压,进而改变无人水面艇的运动状态,实现无人水面艇自主直线路径跟踪；模糊控制器采用双输入双输出的控制结构,无需建立精确的控制器模型,在无人水面艇初始位置相对于跟踪直线的不同位置关系情况下进行了仿真实验,并与PID控制器的性能进行了比较,仿真结果表明:在初始航向偏差角较大时,如2π/3、π时,该方法克服了采用固定参数PID控制方法时出现的大迴转现象；在初始航向偏差角较小时,如π/4、3π/7、π/2时,该方法在超调量以及调节时间方面的直线跟踪性能优于固定参数PID控制方法。

Abstract:

A straight path tracking method of an Unmanned Surface Vehicle(USV)based on fuzzy control is presented in this paper for the electrically propelled USV,who was equipped with twin fixed propellers. We determine the current state of the USV by the distance of the USV to the target path and the difference between the actual heading direction and the given path. The fuzzy algorithm is used to adjust the input voltage of the right and left propulsion motor timely to change the motion state of the USV, so that the USV can track a straight line autonomously. The fuzzy controller has two inputs and two outputs, and accurate mathematical models needn’t to be established. The simulating experiments in different cases of initial position and pose of the USV with respect to the straight line demonstrate the effectiveness of the method. By comparing with the PID method, The simulating experiments show that the proposed method can avoid the big gyration that appears when PID controller is used at large initial deviation of course angle, e.g.,. In comparison with PID controller, the fuzzy PID has better performance in overshoot and regulation time at small initial angle deviations, e.g.π/4,3π/7,π/2.