Operational Space Calibration for Remote Welding Based on Surface Tracking With Shared Force Control

This paper presents a novel operational space calibration approach for robotic remote welding based on surface tracking with shared force control. A human-machine shared force controller is designed to combine manual control with local force control. A position-based force control strategy for surface tracking on the constrained motion plane is adopted. A precise method to measure the contact point’s spatial location during the surface tracking process is proposed. The operational space calibration for the L-pipe part is solved by direct least-squares fitting algorithm of elliptic tracking trajectory and L-pipe part calibration algorithm. The experimental results show that the proposed calibration method can make the operational space model error less than 1mm, which meets the requirements of carrying out assembling contact tasks during the remote welding process with passive compliance.