Application Research on Anti-Sway Positioning for Overhead Cranes Using Industrial Frequency Converters

This paper presents a vision-based anti-sway control system for industrial frequency converters. The system architecture integrates an electrical drive unit, an industrial computer, and an image processing module. The system architecture integrates an electrical drive unit, an industrial computer, and an image-based sensing module. The drive unit incorporates programmable logic controller (PLC), vector-controlled inverters, and AC induction motors. A coupled trajectory planning and tracking algorithm, based on crane kinematics, enables simultaneous positioning and sway suppression. The controller employs velocity–position compensation for real-time trajectory generation, while a camera-based sway-angle observer provides stable feedback under modeling uncertainties and external disturbances. Featuring a compact structure and minimal tuning effort, the control framework explicitly considers velocity and acceleration constraints. Experimental validation on a 42-ton overhead crane demonstrates a trolley positioning accuracy of ±10 mm and a residual sway of ±0.1° during three-dimensional coordinated motion.