$H_{\infty}$ Depth and Course Controllers Design for Autonomous Underwater Vehicles

Abstract

In this paper, H(sub) depth and course controllers of autonomous underwater vehicles using H(sub) servo control are proposed. An H(sub) servo problem is foumulated to design the controllers satisfying a robust tracking property with modeling errors and disturbances. The solution of the H(sub)servo problem is as follows; firest, this problem is modified as an H(sub) control problem for the generalized plant that includes a reference input mode, and than a sub-optimal solution that satisfies a given performance criteria is calculated by LMI(Linear Matrix Inequality) approach, The H(sub)depth and course controllers are designed to satisfy the robust stability about the modeling error generated from the perturbation of the hydrodynamic coefficients and the robust tracking property under disturbances(was force, wave moment, tide). The performances(the robustness to the uncertainties, depth and course tracking properties) of the designed controlled are evaluated with computer simulations, and finally these simulation results show the usefulness and applicability of the propose H(sub) depth and course control systems.