Aiming at the problem of time-grating turntable precision reducing induced by sensor mounting eccentric or environmental changes and so on

present automatic calibration system for time-grating turntable which calibrates error by polygons and autocollinator and use harmonic wave correcting technology for error correction.Polygons and autocollinator high-precision measuring instruments are applied to the system as measuring standard

ARM processor is used as core to carry out closed-loop control on stepper motor and achieve precise positioning

and the system can carry out data acquisition and error processing. Experimental result shows that compared with manual mode

the calibration system is not only high efficient

but also indexing precision can reach ± 1. 3" after calibration.