Collision-free flexible performance tracking control against moving obstacles for underactuated surface vehicles with model uncertainty and input saturation

Abstract

This paper presents a novel tracking control method based on a collision-free flexible performance function (CFPF) that allows us to preset tracking performance bounds for uncertain underactuated surface vehicles in the presence of moving obstacles and input saturation. In contrast to previous studies that have utilized flexible performance functions, we introduce a new CFPF combined with alteration signals to adjust the tracking performance against moving obstacles with unknown velocities. The CFPF-based adaptive control design strategy is established using the coordinate transformation method and auxiliary variables, where the CFPF tuning mechanism is derived from a Lyapunov-based tracker design. By employing the Lyapunov stability theory, we prove that the proposed method allows for the desired tracking performance adjustment, thereby ensuring trajectory tracking and obstacle avoidance despite model uncertainty, input saturation, and unknown moving obstacles.