Abstract
This paper presents a practical compensation method for parameter variations of galvano scanners in laser drilling machines. In the galvano scanner, plant parameters, such as torque constant of motor, mechanical resonant frequencies, and viscous friction in mechanism, vary according to temperature rise and/or age-related deterioration. As a result, the positioning performance deteriorates owing to variations from the nominal condition. In this study, therefore, a practical estimation and compensation method for the variations is proposed in order to improve the settling performance, where fluctuations in settling waveforms are comparatively analyzed by a precise positioning simulator. Based on the analyses, the fluctuations are approximately expressed by simultaneous equations, while the parameters are identified by solving the equations using a multiple regression analysis. Then, a feedforward controller is redesigned with the identified parameters. The proposed compensation approach has been verified by numerical simulations and experiments using a positioning device for actual galvano scanners.
