Research on double-USVs fuzzy-priority NSB behavior fusion formation control method for oil spill recovery

Replacing manned ships with unmanned surface vehicle (USV) for oil spill containment can reduce the consumption of manpower and resources. This article studies the formation control method of dual USVs during the process of capturing oil spill, based on the engineering background of towing oil boom by dual USVs oil spill recovery system. To calculate the drag force of the oil boom acting on the USV, the shape of the oil boom is simplified into a catenary, the oil boom is modeled, and the hydrodynamic numerical simulation is carried out. To address the issue of “winding” phenomenon and “towing separation,” the formation behavior is designed when double USVs are towing oil fences to capture oil spill. In response to the problem of low task execution efficiency caused by fixed behavior priority in traditional null-space-based (NSB) behavior fusion methods, a fuzzy-priority NSB (FNSB) behavior fusion formation method is proposed by combining fuzzy control with NSB behavior fusion method. In the FNSB behavior fusion formation control method, a smooth transition rule is introduced to make the behavior priority change, USVs can still maintain good formation performance, ensuring the smooth execution of oil spill recovery tasks. Simulation shows that FNSB behavior fusion formation method based on flexible transition rules can improve the rounding efficiency by 26.6% in the environment without obstacles and 37.2% in the environment with multiple obstacles compared with the NSB method. The effectiveness and practicality of this method have been verified through simulation experiments and field experiments on the “Dolphin” series of small USVs.