回转误差测试中系统噪声分离技术

高精度主轴的回转误差和测试系统的噪声常处于同一水平，这极大地影响了用频域三点法测量主轴回转误差的准确性。针对同步误差（SEM），提出了对含噪声信号进行等角度采样重构、集合平均和小波滤波的组合降噪处理方法，提出了根据传感器和被测主轴直径定量确定小波分解层数的方法，经仿真实验证明其具有良好的去噪效果。针对异步误差（ASEM），提出了消除测试系统噪声的方法，研究了圈数对异步误差测试结果的影响规律。此外，搭建了测试系统，验证了所提方法的有效性。 

Separation technology of system noise in error motion test

Since the error motion of the high-precision spindles is often in the same order as the noise of the test system, the measuring accuracy of the three-point method is greatly reduced by the noise signals. With the synchronous error motion (SEM), a combined processing algorithm with equal angle sampling and reconstruction, ensemble average filtering and wavelet filtering for noise-containing signal is proposed. A method for quantitatively determining the wavelet decomposition layer based on the diameters of both sensor and measured spindle is proposed. The simulation results show that the new combined method has good denoising effect. With the asynchronous error motion (ASEM), a method for eliminating the noise of the test system is proposed, and the influence of the number of test cycles on ASEM is studied. In addition, a test system was built and the effectiveness of the proposed methods was experimentally verified.