Research on Automatic Centering System of Stationary Welding Machine in Rail Welding Workshop

Aiming at the problems such as long centering time and low accuracy during the centering of the line of rail before welding by using stationary rail AC welding machines, a full-automatic centering system was developed based on high precision laser sensors and programmable logic controllers. Six laser sensors were used to design the distance measurement device of the active line of rail at the dynamic clamping end and the static clamping end from the reference position to realize the error data detection of the active line of two rails. Based on PLC, variable frequency controller, three-phase AC motor and turbine worm reducer, the relative position adjustment mechanism system hardware of the moving end and static end was designed. Aiming at the real-time response of the centering adjustment mechanism hardware and the clearance of the mechanical structure, the related control algorithms in the automatic centering system were studied. The upper computer monitoring platform developed based on Visual basic was used for real-time monitoring and data testing of various control algorithm debugging and centering processes. The test results of the automatic centering system show that: the control accuracy and real-time performance of the PD control algorithm meet the requirements of the entire welding rail. The variable PID parameter control method based on the error size can further improve the accuracy of the system and shorten the adjustment time of the system within the full deviation range.