Cascaded adaptive control of ocean vehicles with significant actuator dynamics

This paper presents a cascaded adaptive control scheme for marine vehicles where the nonlinear equations of motion include a model of the actuator dynamics. The adaptive controller does not require the parameters of the vehicle dynamics and the actuator time constants known a priori. Both the velocity and position tracking errors are shown to converge to zero by applying Barbalat's lemma. Furthermore, all parameter estimates are shown to be bounded. Computer simulations of a remotely operated vehicle (ROV) is used to illustrate the design methodology. Key Words: Adaptive control; nonlinear systems; marine systems; actuator dynamics. 1 INTRODUCTION Adaptive control theory have been successfully applied to ocean vehicles like underwater vehicles, submersibles and surface ships. However, most of these methods are based on the assumption that the actuator dynamics can be neglected in the control design. Including a model of the actuator can improve the robustness and performance of the...