In context
In 2024, space docking mechanisms demanded high-precision ground testing to ensure safe rendezvous without collision or rebound. Traditional full-physical simulation using air-floating devices struggled with 6-DOF operation and costly reconfiguration for varying mass and inertia. Semi-physical simulation, combining robots with mathematical models, offered a flexible and cost-effective alternative, but faced challenges in dynamic response and accuracy.
What was reported
Researchers from Shenyang University of Chemical Technology and the Chinese Academy of Sciences proposed a force-compliance-based semi-physical simulation method for 6-DOF space docking. The approach integrates gravity compensation and admittance control to simulate compliant docking motion, using a KUKA robot, 6-dimensional force sensor, PXI computer, and PC. Drive delay compensation was introduced to enhance system performance.
The gravity compensation method accounts for sensor installation tilt angles, zero-point drift, and end-effector load gravity, enabling precise external force measurement. Admittance control uses the measured force as input to generate position corrections, improving force-following behavior. Drive delay compensation addresses lag in robot response.
Experimental results showed that the proposed method improved external force perception accuracy, dynamic response speed, and docking precision compared to prior approaches, meeting requirements for high accuracy, high DOF, good sensor fusion, and fast response.
Why it mattered
This work demonstrated a practical approach to enhance semi-physical simulation fidelity for space docking, offering a template for high-precision ground testing in aerospace. The combination of gravity compensation, admittance control, and delay compensation could extend to other industrial automation tasks requiring compliant interaction and precise force control.
The experimental results show that the proposed method enhances the external force perception accuracy of the robot, and at the same time improves the dynamic response speed and docking accuracy of the force-following compliant docking process.
Source: 《机器人》期刊 (robot.sia.cn) · Published 2024-05-08 · “基于力柔顺性的航天对接半物理仿真”