Multi-mode fault-tolerant trajectory tracking control of AUV under thruster failure conditions in complex environments

This paper addresses the problem of fault tolerance during tracking control of autonomous underwater vehicles (AUVs) in complex environments, especially to ensure the effectiveness of trajectory tracking control under multiple failure modes. Firstly, a 4-thrusters AUV dynamics model is designed to enhance the flexibility of AUV motion. Second, a kinematic controller and a dynamics controller are designed for the model. A velocity-dependent intermediate control law is used in the kinematic controller to enhance the kinematic control accuracy, and the stability of the kinematic control system is demonstrated. Then, an integrated adaptive fault-tolerant controller was constructed by combining the fault-tolerant control scheme based on the AUV force structure with the dynamics controller. Meanwhile, the controller can effectively solve the unknown component of each thruster existing in the trajectory tracking process by conjugate integral control, which ensures the effectiveness of the total thrust under the condition of multiple failure modes in the process of cooperative control of the thrusters. Finally, the simulation shows that the control scheme can effectively solve the fault-tolerant control problem under multiple thruster failure modes during AUV trajectory tracking.