Active Disturbance Rejection Control of Underwater Vehicles under External Disturbances

Active Disturbance Rejection Control (ADRC) inherits from Proportional-Integral-Derivative (PID) control, and employs an Extended State Observer (ESO) to estimate system uncertainties including uncertain model parameters and external disturbances. In this paper, we design a trajectory tracking controller for fully-actuated underwater vehicles using the ADRC approach with consideration of the environmental disturbances generated by waves and currents during the operation. In order to adjust the control parameters online, a Radial Basis Function (RBF) neural network-based parameter optimization method is introduced to improve control system performances. In the simulation experiment, the underwater vehicle moves accurately along the desired helix trajectory under the effects of waves, which verifies the effectiveness of ESO and the robustness of the proposed ADRC-based method to system disturbances.