Wave Disturbance Rejection for AUV Heading Control Based on Internal-model-principle

This paper presents an optimal internal model control (OIMC) algorithm for heading control problem of underactuated AUV systems affected by wave disturbances. Firstly, the AUV nonlinear system model is converted to the system model by differential homeomorphism. And the exosystem of wave force disturbances is obtained based on the Morison equation. Secondly, the disturbances compensator is designed by using internal model. And a new augmented system is constructed, by taking the system and the disturbances compensator in series. Then the optimal control problem of AUV nonlinear system is transformed into the optimal regulator design problem of an augmented system. The optimal internal model control law is designed according to the different quadratic performance index. Finally, the controller is applied to the heading control of AUV with wave force disturbances, and the results demonstrate the effectiveness and robustness of the controller.