High accuracy position system using linear stepping motor drive - has phase angle displaced input current signals used with correction process applied

摘要

The linear stepping motor drive system has a personal computer (2) with D/A cards (4), coupled to a power amplifier (3) that supplies the moving parts (7) of the motor. The motion is measured by a laser position sensor (11). The motor has the moving part and a stator (7) separated by an air film. The moving part has soft iron cores with inset coils. The two core and coil arrangements are excited by phase displaced frequencies. The ratio between the two current drives is determined and tabulated values used as input. ADVANTAGE - Provides accuracy in the range of +/- 30 micrometer.