Appointed-time Prescribed Performance Control for Shipborne SideArm with DRL-based Kinematic Compensation

During the recovery of fixed-wing unmanned aerial vehicles (UAVs) by a SideArm, the motion of the desired docking point (DDP) on the arresting cable located at the SideArm’s tip is heavily influenced by the ship’s movements. The movements increase the complexity and risk of the docking procedure. As a means of stabilizing the spatial position of the DDP, this paper presents a novel control framework that integrates kinematic solutions and dynamic control strategies. The proposed framework first compensates for the ship’s six-degrees-of-freedom motion, then generates the basic joint signals of the SideArm using a geometry-based inverse kinematic (IK) method. The twin delayed deep deterministic policy gradient (TD3) algorithm is applied to compensate for these signals, forming the IK-TD3 approach that enhances the accuracy of the DDP’s spatial position. An appointed-time prescribed performance control method is designed to ensure that the system’s performance remains within predefined constraints and converges within a preassigned time. A fixed-time disturbance observer is introduced to estimate the lumped disturbances and uncertainty dynamics of the SideArm. A comprehensive set of simulations and experiment considering different sea states demonstrates the reliability of the proposed approach.