Transfer Learning for Deep Reinforcement Learning-Based Path Following of Autonomous Surface Vessels
摘要
Deep Reinforcement Learning (DRL) offers a powerful, model-free, and data-driven approach for the navigation and control of Autonomous Surface Vessels (ASVs). The primary challenge, however, lies in the extensive training required for an agent to converge to an effective policy within a complex simulation, leading to significant computational overhead. This paper presents a multi-stage training framework that uses Transfer Learning to pass knowledge between different simulation models, resulting in a highly robust DRL controller for ASVs. The proposed framework utilizes the Deep Deterministic Policy Gradient (DDPG) algorithm to develop the data-driven controller. First, a foundational policy is efficiently learned using a simplified first-order Nomoto dynamics and second-order Nomoto dynamics, which captures the fundamental vessel dynamics. This pre-trained policy is then transferred to a complex, nonlinear Manoeuvring Modelling Group (MMG) model, significantly accelerating training convergence. Subsequently, the agent is fine-tuned within the MMG simulation with environmental disturbances. The models are evaluated on various trajectories during testing to ensure robust performance. The accuracy of the DRL controller is assessed by measuring heading error (eψ) and cross-track error (ye). A traditional Proportional-Integral-Derivative (PID) controller is implemented and compared to benchmark the DRL controller’s effectiveness, to highlight the relative advantages and limitations of each approach.