限制区域水面无人艇路径规划与跟踪控制研究

Study on path planning and following control of unmanned surface vehicles in restricted areas

路径规划与跟踪控制是水面无人艇自主航行的关键技术。首先,采用概率地图法(PRM)对水面无人艇的路径规划进行了研究,详细介绍了概率地图法的原理以及算法实现流程,针对传统方法在工程实际中存在的问题,结合无人艇操纵性能约束提出了简单有效的改进方法,进行了算例验证;其次,以PRM规划路径为目标对象,开展了欠驱动无人艇路径跟踪控制技术研究,对操舵响应非线性模型进行线性化处理,考虑舵角饱和约束限制,设计了模型预测控制器,舵角的执行指令可以通过二次规划算法求解;最后,进行了限制区域水面无人艇路径规划和跟踪控制的联合仿真验证。研究结果表明:概率地图法可以成功地应用于限制区域无人艇路径规划,方法可实现性好、效率高;规划所得的路径由一系列直线段组成,有利于路径跟踪控制;通过模型预测控制可以快速平稳地实现欠驱动无人艇对目标路径的跟踪控制。

Path planning and following control are both crucial technologies for autonomous navigation of unmanned surface vehicles(USV).Firstly,path planning of USV by probabilistic roadmap method(PRM)is presented in this paper.The principle of PRM and its algorithm flowchart are introduced in detail.In view of shortcomings of the traditional PRM,some effective improved methods are proposed in combination with the maneuvering performance constraints of USV,and then validated by some numerical examples.Secondly,based on PRM planning path,nonlinear steering response model is linearized for the controller design and the path following control strategy is studied.The model predictive controller(MPC)is formulated,considering rudder saturation constraints.The rudder control command can be solved by quadratic programming optimization.Numerical simulations of path planning and following control in restricted waters are carried out.The results show that PRM is efficient and can be successfully applied in USV path planning in restricted waters.The planning path by PRM consists of a series of straight-line segments,which is conducive to path following control.And the target path following of USV can be implemented quickly and smoothly by MPC.