Design of an embedded optical fiber micro-displacement measurement system

摘要

Design of an embedded optical fiber micro-displacement measurement system is presented. It consists of an optical fiber displacement sensor, a signal pre-processing unit and an embedded microprocessor unit of ADuC812. The displacement sensor is a reflective intensity-modulated optical fiber bundle sensor with two paths of optical signal output, so influences of light resource fluctuation and other common interferences such as external environment and fiber loss are reduced. The signal pre-processing unit consists of several functional circuits, such as optical-electrical transducer, pre-amplification unit, band-pass filter and phase sensitive detection circuit, and is used to transform the two paths of optical signals mentioned above into two paths of electrical signals. ADuC812 is an advanced embedded microprocessor module with high performance and low price. In this application, it is used to accomplish functions of two paths of signals sampling, signals dividing and signal nonlinear processing, and finally output an analog voltage in proportion with the measured displacement. By introducing the embedded microprocessor module of ADuC812, the measurement performance and intelligent extent of the micro-displacement measurement system can be improved, resulting in the wide applications in advanced manufacturing and testing.