基于精确罚函数的无人艇航迹规划和自动避障算法

目的]对于已知多个障碍物的局部水域,如何规划安全高效的无人艇(USV)运动航迹,是当前的研究热点。方法]首先,采用简洁有效的圆形包络面和凸四边形包络面处理障碍物区域,并将避障问题转化为时间最优控制问题中的状态不等式约束;然后,利用控制参数化和时间尺度变换,将时间最优控制问题转化为最优参数选择问题;最后,对于由多个障碍物带来的多个连续状态不等式约束,采用精确罚函数法将所有的状态约束都附加到目标函数中,从而构建适用于任何有效优化技术予以求解的非线性优化问题。结果]数值仿真结果表明,该算法所规划的航迹能成功规避水域中的所有障碍物,同时符合无人艇的运动特性。结论]研究成果可为无人艇航迹规划的避障问题提供参考。

Trajectory planning and automatic obstacle avoidance algorithm for unmanned surface vehicle based on exact penalty function

Objectives]Currently, how to plan the safe and efficient movement trajectory of an unmanned surface vehicle(USV) in local waters with multiple known obstacle positions is a research hotspot.Methods]First, the obstacle areas are treated with simple and effective circular and convex quadrilateral envelopes, and the obstacle avoidance problem is transformed into the state inequality constraint of a time optimal control problem. The time optimal control problem is then transformed into an optimal parameter selection problem by control parameterization and time scale transformation. Finally, for multiple continuous state inequality constraints caused by multiple obstacles, the exact penalty function method is used to append all state constraints to the cost function. The final form of the problem is suitable for solving any effective optimization technique as a nonlinear optimization problem.Results]The numerical simulation results show that the planned trajectory successfully avoids the obstacles in the water and conforms to the motion characteristics of USVs.Conclusions]The results of this study can provide valuable references for the obstacle avoidance problem in USV trajectory planning.