Study on Measurement of Error Motion and Stiffness for Precision Spindles

Abstract：To improve the measuring accuracy of error motion, it's necessary to filter to eliminate the noise in the displacement signals when using the three-point error separation technique.After comparing the effects in different filtering methods with simulation and experiment, the paper proposes the ensemble average and wavelet combing denoising method which can significantly improves the separation accuracy of synchronous error motion (SEM).By measuring the system noise separately and considering that asynchronous error motion (ASEM) and noise are independent with each other and obey the normal distribution, a method to improve the separation accuracy of ASEM is proposed.As for the stiffness test under high speed condition, a novel method using partial air bearing to load spindle shaft is proposed.A non-contact loader with five degrees of freedom adjustment function is successfully developed and its effectiveness is verified by experiment.