Auto-heading Control of an Over-actuated Underwater Vehicle Based on Active Disturbance Rejection Control and Optimal Thrust Allocation.

In practical applications, over-actuated underwater vehicles are vulnerable to various environmental disturbances caused by effects of water currents, nonlinear characteristics of propulsion systems, and other factors. Therefore, an improved control strategy is important for the over-actuated remotely underwater vehicle (ROV) to solve the nonlinear influences of water current and model uncertainties. Motion control and allocation control are the two components of the control strategy described in this work. The motion control system based on the active disturbance rejection control (ADRC) theory is used to increase the system's robustness against the effects of the water current and hydrodynamic force. Then, aiming at the problems of saturation phenomenon and low accuracy of thrust allocation in over-actuated ROV, according to the three-dimensional arrangement of underwater robot propeller thrust distribution mathematical model, on this basis, the modified objective function of sequential quadratic programming (SQP) algorithm, overcame the SQP algorithm optimization unstable faults. In order to assess the potency and reliability of the suggested control strategy, simulation studies are conducted. The findings demonstrate that the suggested control strategy offers more stability, a smaller steady-state error, and greater robustness.