Concentric Dual Circular Track Large-Span Overhead Crane: Key Technologies Taking Shanghai Light Source, Beijing Light Source, and Hefei Light Source Projects as Examples

Description: This study addresses the unique technical challenges of large-span overhead cranes operating on concentric dual circular tracks within synchrotron radiation light source storage rings. Drawing on three major projects—Shanghai Synchrotron Radiation Facility (SSRF), High Energy Photon Source (HEPS), and Hefei Advanced Light Facility (HALF)—three core technologies are systematically investigated: PLC closed-loop control, curvature-coupled three-layer precision control, and differential-speed synchronous driving. A three-layer precision coupling model encompassing the wheel-rail layer, measurement layer, and control layer is established, together with a gap–closed-loop coupling theory. On-site commissioning of the HALF project demonstrates that the synthesized three-layer precision reaches ±0.62 mm, satisfying the ±1 mm design specification with a 38% safety margin. This work fills the domestic technology gap in concentric dual circular track large-span overhead cranes and provides a theoretical basis and engineering reference for the design and manufacture of similar large-scale precision lifting equipment.