Error testing and compensation of the time-grating angle measurement system

In order to remove the subdivide error and zero error to improve the measurement precision of time-grating displacement sensor angle measuring system, this paper proposed an error compensation method based on sparse sampling. Firstly, harmonic analysis and the error compensation model of the induction signal for time-grating sensor displacement angle measuring system is performed. Then, laser interferometer and time-grating sensor are used to synchronous sample positions at the poles and interior single-pole. Finally, the subdivide error and zero error of measurement are corrected by the compensation model. A time-grating sensor system with 72 poles are taken as subject to test, the result shows that:the peak to the peak value of the measurement error reduces from 138 '' to 2.69 '', this is to say, the accurate degree raised 51 times than before. Besides, this method provides full-circle error compensation with fully cancel the subdivide error and zero error based on sparse sampling which greatly improves the correction efficiency and measurement accuracy.