H_∞ robust control design for coupled Ciscrea AUV model

  Objective  A multi-input multi-output (MIMO) robust controller is proposed to realize the trajectory tracking and yaw control of a four-DOF Ciscrea autonomous underwater vehicle (AUV) model.

  Methods  The parameter uncertainty of the inertia matrix and quadratic damping action is formulated as an uncertain structure via the perturbation method, and the general system is derived by linear fraction transformation (LFT). The H-infinity synthesis method is applied to solve the MIMO robust controller for the AUV general system, and the structure singular value analysis method is used to compute the robust stability margin. To validate the robust yaw controller, AUV's three-dimensional trajectory tracking and yaw control scenarios are simulated using MATLAB. The tracking performance is compared between interference and non-interference control conditions.

  Results  The upper and lower bounds of the structure singular value are obtained for the stable robust controller.The elimination of perturbation on AUV output shows effective anti-jamming performance.

  Conclusions  The proposed control method is available for solving the parameter uncertainty and nonlinearity issues of AUV models, which can provides a specific application for addressing AUV motion and attitude control problems in real ocean environments.