Autopilot Design for Autonomous Underwater Vehicles Based on Sliding Mode Control

摘要

An autopilot is designed using Sliding Mode Control Theory that can control thespeed and heading of a full six degree of freedom, nonlinear model that allows speed and heading to be treated as separate systems. Once control of heading and speed is established, depth control is achieved by a third control law. Although they are developed separately, the three individual control laws act simultaneously to provide robust control of speed, heading, and depth of the nonlinear model of the vehicle. Line of Sight Guidance is used to convert the way points provided by the mission planner into commands for heading to which the autopilot responds. The performance of the autopilot is evaluated over a wide range of speeds to demonstrate its robustness. In addition, the effects of current are simulated and the autopilot is modified to compensate for the presence of a strong current.