Impedance Control of Ship-Borne Manipulators via Optimization-based Task-Space Inverse Dynamics

2026-07-24

AI Summary

This study addresses the challenge of simultaneously achieving high trajectory tracking accuracy and safe contact interaction for shipboard manipulators under stochastic wave-induced disturbances. The authors propose an optimization-based control framework grounded in Task-Space Inverse Dynamics (TSID), which unifies precise trajectory tracking and task-space impedance control at the torque level. Dynamic coupling induced by the moving base is explicitly compensated via a quadratic programming formulation. By integrating an Error-State Kalman Filter (ESKF) with multi-source sensor fusion, the system achieves millimeter-level peg-in-hole insertion on a dynamically moving platform for the first time. Experimental results demonstrate over a 25.7% reduction in end-effector tracking error, a significant increase in successful insertions into 1-mm clearance holes, and a 45% reduction in average contact force.

Abstract

Ship-borne manipulators operating in maritime environments are subject to stochastic wave-induced base motions that introduce kinematic disturbances and dynamic coupling, degrading trajectory tracking accuracy and complicating safe, contact-rich manipulation. This paper proposes a torque-level optimization-based control framework that integrates high-precision trajectory tracking with task-space impedance for ship-borne manipulators. The controller is formulated using task-space inverse dynamics (TSID) and solved via quadratic programming to explicitly compensate for the dynamic coupling introduced by base motion. To enable accurate feedforward compensation, an error-state Kalman filter (ESKF) is developed to estimate the base state by fusing inertial measurements with end-effector pose feedback. The framework is validated in simulation and real-world experiments using a 7-DOF manipulator mounted on a 6-DOF Stewart platform. The proposed method reduces real-world end-effector position tracking error by over 25.7% compared with the best baseline. Furthermore, the controller enables dynamic peg-in-hole insertion with 1~mm clearance under base motion, increasing the success rate while reducing average contact forces by 45%, demonstrating precise and compliant manipulation in contact-rich environments.

Problem

• ship-borne manipulators
• wave-induced base motion
• trajectory tracking accuracy
• dynamic coupling
• contact-rich manipulation

Innovation

• task-space inverse dynamics
• impedance control
• error-state Kalman filter
• base motion compensation
• quadratic programming