Extended State Observer-Based Control of Underactuated Autonomous Underwater Vehicle in a Vertical Plane

In this paper, a control system is designed for a path following problem of a flight-type underactuated autonomous underwater vehicle (AUV) operating in a vertical plane. Initially, a guidance law is formulated based on a desired path tangential angle and vertical cross-track error. The guidance law generates the pitch angle reference for the pitching motion of the vehicle such that the cross-track converges to zero. A pitching control system is constructed based on the extended state observer-based controller (ESO) for the AUV to track the commanded pitch angle value with stern deflection angle as a control input. The resulting diving motion drives the AUV to reach and follow the reference path. For the purpose of evaluating the effectiveness of the control system design, numerical simulations are conducted.