Energy-Efficient and Actuator-Friendly Control Under Wave Disturbances: Model Reference vs. PID for Thruster Surge

Abstract: In this study, we compare a model reference control (MRC) strategy against conventional PID controllers (tuned via metaheuristic algorithms) for surge velocity control of a thruster-driven marine system, under combined wave disturbance and sensor noise. The goal is to evaluate not only tracking performance but also control energy usage and actuator stress. A high-order identified model of a Blue Robotics T200 thruster with a 2~kg vehicle is used, with an 8~N sinusoidal wave disturbance applied and white noise ( added to the speed measurement. Results show that the optimized MRC (MRC-R*) yields the lowest control energy and smoothest command among all controllers, while maintaining acceptable tracking. The IMC-based design performs closely. In contrast, PID controllers achieve comparable RMS tracking error but at the cost of excessive actuator activity and energy use, making them impractical in such scenarios. Future