Backstepping method with PID gain tuning in diving control of autonomous underwater vehicle
具有PID反馈增益的自主水下航行器反步法变深控制

To deal with the problem of diving control for an autonomous underwater vehicle (AUV) in oceanographic mapping survey, we propose a depth control method with PID gain tuning function. In designing the controller, the requirement of the higher order derivative of virtual control variable is eliminated by adopting the backstepping method based on the feedback gain instead of the traditional backstepping method. Part of nonlinear terms is removed in the design of controller parameters by using Lyapunov stability theorem, resulting in a linear controller which is composed of state variables with PID gain tuning function. Robustness analysis is performed on the system which is uniformly ultimately bounded in the presence of model uncertainties, external disturbances and measurement noises. Simulation results show the validity and the effectiveness of the proposed controller.