Study on Optimal Tuning of PID Autopilot for Autonomous Surface Vehicle

Abstract

An autonomous surface vehicle (ASV) is developed to support the research on autonomous underwater vehicles. The ASV is required to exhibit route tracking that traces an underwater vehicle. To improve the tracking control accuracy of an ASV, its control gain must be optimized. Therefore, a tuning method that optimizes the PID control gain for tracking control is introduced herein. First, the gain is obtained from describing function method and Ziegler–Nichols’ ultimate gain method. Next, an evaluation function that focuses on the tracking control is created. Subsequently, the gains are optimized for tracking control using the evaluation function. A tank test using an actual surface vehicle is performed and the results demonstrate the effectiveness of the proposed method.