Plasma arc cutting torch tracking control

This paper deals with a tracking system of cutting torch´s height for plasma arc process. The computer-based control system consists of a sensing and detection unit, controller and servo actuator. Arc and laser sensors used to detect the torch height, and their performance characteristics are studied in detail. A feedforward compensation of workpiece position is introduced to improve the tracking property. Moreover, the deviation classification and adaptive control approaches are also proposed. The tracking experimental results show the acceptable tracking precision and strong noise-suppression capability of the system. It is also pointed out that the arc sensing approach is more attractive, due to its merits of synchronous sensing, high reliability and low cost.