Double Motor Synchronizing Drive Control for Pipeline Welding Machine Based on CANopen

The tractor speed of all-position automatic pipeline welding carriage was controlled smoothly, which is the important guarantee for improving efficiency of welding and quality of welding. In allusion to the strict demand of synchronization of dual motor driving the running mechanism, the profile velocity operating mode using for vector group based on CAN-open protocol is presented, a novel protocol model named "communication by time-sharing and executing on synchronization" was adopted for simultaneous executing velocity command. Due to a load imbalance problem caused by the discordance of two-axis actual velocity by reason of gear backlash and the coupling relationships between two drive motor by rigid joint, the current compensation algorithm is proposed. Experimentation result indicates that the accuracy of two-axle synchronous movement and the operation stability of welding bug are ensured by using the current compensation algorithm.