A constrained locking sweeping method and velocity obstacle based path planning algorithm for unmanned surface vehicles in complex maritime traffic scenarios

Unmanned surface vehicles (USVs) have wide applicability owing to their high velocities, intelligence, and unmanned operational characteristics, and therefore, they have garnered considerable research interest. To accommodate complex maritime environments comprising static/dynamic obstacles, a novel efficient pathplanning algorithm called the constrained locking sweeping method and velocity obstacle (CLSM-VO) is developed. This algorithm uses the locking sweeping method (LSM) to provide the initial yaw angle for the velocity obstacle (VO) algorithm. While retaining the performance of the VO algorithm, the initial yaw angle based on the LSM can help the VO algorithm optimise the global search performance. Compared with conventional path-planning algorithms, the proposed algorithm demonstrates higher computational efficiency and is applicable to complex dynamic environments with multiple moving obstacles. Additionally, a constraint layer is designed, by combining the proposed algorithm with the yaw-velocity performance of the Tianxing-1 USV, such that the generated path exhibits better smoothness. The adjustable avoidance distance calculated by the proposed algorithm can help prevent collision accidents compared to that by existing algorithms. To evaluate the algorithm performance, particularly the capacity to handle complex dynamic environments, multiple simulations are performed in environments built using electronic nautical charts. The results indicate that the proposed algorithm can effectively handle complex maritime traffic scenarios by generating smooth and safe trajectories.