An obstacle avoidance strategy for the wave glider based on the improved artificial potential field and collision prediction model

Wave glider, as a wave-propelled and persistent unmanned surface vehicle, has attracted wide attention in recent years. Due to its long voyage, the wave glider inevitably encounters various obstacles at sea, which may cause collision accidents. However, the obstacle avoidance for wave glider is challenging because of its special two-body structure and motion mechanism. In this paper, the obstacle avoidance research of wave glider in marine environment is conducted. To address the local minimum in the traditional artificial potential field, an improved artificial potential field (IAPF) is proposed. An eight-degree-of-freedom mathematical model of the wave glider is presented, and the model in series with IAPF is verified under static obstacle environment. Aiming at the obstacle avoidance under dynamic obstacle environment, a fusion algorithm based on the collision prediction model (CPM) and IAPF (CPM-IAPF) is proposed. The algorithm can overcome the obstacle avoidance difficulties caused by the weak maneuverability of wave glider. Various simulations are performed to demonstrate the feasibility and robustness of the proposed strategy. The simulation results show that the wave glider can accomplish the obstacle avoidance task with the proposed CPM-IAPF algorithm when facing with different dynamic obstacles under various marine environments.