基于自适应连续动态比相的时栅位移测量方法研究

Displacement Measurement Method Research of Time-grating Based on Adaptive Continuous Dynamic Phase Comparison

针对时栅传感器由于等时间测量导致测量分辨率随运动速度变化的问题,提出一种基于自适应连续动态比相的位移测量方法。该方法在激励频率不发生变化的情况下,通过速度变化自适应控制一个周期内比相次数,保证不同速度下测量分辨率不发生变化。根据以上方法,建立数学模型,完成硬件电路和软件系统的设计,并搭建实验系统;通过与激光干涉仪在不同速度下对比测量,结果表明,在0~60 cm/s速度范围内实现了将时栅等时间采样值转换为等空间位置反馈,测量精度为±0.5μm.

A displacement measurement method, provided with adaptive continuous dynamic phase comparison, was pro-posed to solve the problem that the resolution was changed under different moving speed, which was decided by average dividingtime measurement of time grating sensor. Under the condition that the excitation frequency was not changed, the times of phasecomparison in a period were self-adaptively controlled by the speed change, which ensured that the resolution was constant at dif-ferent speed. According to the above method, the mathematical model was built, the design of hardware circuit and software sys-tem were completed, and the experimental system was established. Parallel test, compared with laser interferometer, was imple-mented at different speeds. The results show that, within speed 0～ 60 cm/ s, average dividing time sampling value can be transla-ted into equal spatial displacement feedback and the measuring precision are controlled within ±0.5 μm.