Autonomous Control of Redundant Hydraulic Manipulator Using Reinforcement Learning with Action Feedback
Hydraulic-driven redundant manipulators face challenges in autonomous control due to complex system modeling and strong reliance on precise dynamic parameters. Method: This paper proposes an end-to-end data-driven approach requiring only minimal simulation priors and teleoperated demonstration data. It employs Actuator Networks to model nonlinear hydraulic dynamics and integrates forward-kinematics–guided supervision into a modified DDPG framework—enhanced with Ornstein–Uhlenbeck noise for exploration—to directly output joint-level commands for 3D end-effector pose tracking. Contribution/Results: We introduce, for the first time, kinematic feedback within the RL action-selection mechanism, eliminating the need for system identification, inverse-dynamics modeling, or post-deployment fine-tuning. Evaluated on a scaled 3R1P hydraulic logging crane, the policy trained purely in simulation transfers zero-shot to hardware, achieving high-precision 3D position tracking. This significantly advances the feasibility and robustness of data-driven control for strongly nonlinear hydraulic systems.