Design Of A Strain Measurement Instrument Based On Michelson Fiber Optical Interferer Sensor

In this paper, a kind of fiber optic interferential sensing instrument based on Michelson principle has been designed. This instrument demodulated the strain signal by Michelson fiber optical interferer sensor. The demodulated optical signal was changed into the electric signal by optic-electric conversion circuit. Then the signal was collected by through the signal processing circuit and the direction-judgment & counting circuit. MCU controller circuit, the core of the instrument, was designed to realize the collection, storage, display and transmission of the data. CPLD was responsible for direction-judgment and counting. The instrument with simple configuration and high accuracy matched the demand of actual item well.This paper, firstly, introduced the theory of Michelson fiber optical sensor, and analyzed the conditions of the occurrence of interference phenomenon and the composing of Michelson fiber optical interferer sensor. Then it focuses on the operational principle and main components of fiber optical sensor based on 3×3 directional coupler.Secondly, the paper expounded hardware and software design of the instrument. It emphasized the design process of the measurement system and analysis to the components of the measurement instrument in detail. Design of the signal processing circuit, the direction-judgment & counting circuit, and the MCU controller circuit was completed. Design of the system software was also completed to realize the collection, storage, display and transmission of the data.At last, the related experimentation has been carried out and the related datum also has been analyzed.