Research on Multi-channel Digital and Analog Signal Synchronous Acquisition Method for Low Coherence Interferometric Measurement Systems
In modem engineering,the importance of simultaneous acquisition of analog and digital signals is more and more signifi-cant.Simultaneous acquisition of both types of signals can improve the accuracy and reliability of data acquisition and processing,and avoid problems such as data delays and jitter,which are highly necessary especially for some specific application scenarios.In order to adapt to the synchronous acquisition and processing requirements of multiple types of multi-channel signals in low coherence interfer-ometry systems,a digital signal conditioning board was designed and fabricated based on the existing data acquisition instrument,and the synchronous acquisition of digital and analog signals was verified through experiments.The experimental results indicate that the de-signed system can not only achieve high-speed synchronous acquisition of two types of signals,but also has high accuracy in displace-ment acquisition:within the range from 0 mm to 70 mm stroke of the electric displacement stage,the maximum error is 2.52 μm and the maximum error for the piezoelectric displacement stage from 0 μm to 320 μm stroke is only 0.54 μm.