PID 제어기법을 이용한 펄스 레이저 출력 안정화에 관한 연구

Pulse Laser Power Stabilization Using PID Control Method

  In this study, PID control method was applied to decrease the power fluctuation of the pulse laser which is one of the major processing variables in laser machining process. To stabilize the power fluctuation of the pulse laser, we averaged 10 pulse outputs of Nd:YAG laser operating in 10Hz using boxcar averager, and with taking this averaged output as an input signal, we conducted PID control using optical attenuator which is consisted of half wave plate attached on the stepping motor and polarizer. When PID control was not enabled, the power fluctuation was 4.71％ and with PID control, the power fluctuation was 1.86％ for 2 hours and 1 hour respectively. As a result, we stabilized the power fluctuation of the pulse laser by 60.5％