Hybrid Adaptive Path Planning for a USV under Complex Marine Environment

In this paper, a hybrid adaptive path planning (HAPP) scheme based on global path planning and local dynamic collision avoidance for unmanned surface vehicles (USVs) under complex marine environment is proposed. The salient features of the proposed scheme are: (1) In order to ensure that the USV can navigate safely, an improved obstacle swelling binary (IOSB) map is established. (2) In order to generate effective sparse waypoints in the complex marine environment, a novel global path planning algorithm, called IOSB adaptive Theta* (IOSB- AT*) is developed, and the waypoints are converted into a smooth path suitable for USVs after employing the B-spline fitting algorithm. (3) In order for the USV to cope with real marine environment containing dynamic obstacles, an improved dynamic window approach is proposed. Simulation and comparative studies demonstrate the safety, effectiveness and real-time performance of the proposed hybrid path planning scheme under complex marine environment.