New vacuum electron beam processing method based on temperature closed-loop control

This is a novel combination of vacuum electron beam (EB) processing and automatic control theory. The concept of full EB processing method was presented. The digital control system for temperature closed-loop control in EB processing based on scanning track control was realized. The method of controlling electron beam current and heating power by real-time adjusting grid bias voltage is feasible. EB processing methods consist of two stages: heating-up stage and temperature maintaining stage. In the former stage, a fuzzy controller was used to control the temperature rising velocity, the sensitivity of the control was evaluated; in the latter stage, an integral separation PID controller was used to keep the workpiece's temperature constant, ideal static and dynamic performances were obtained. The temperature rising velocity control and the maintaining control compose the full EB processing method, the transition of the two stages is bumpless.