Based On The Dsp Of The Laser Interferometer Signal Acquisition And Processing System

Along with the theory study of the laser self-mixing interference becoming maturer increasingly,the application in vibration,micro-displacement and velocity measure based on this technology become broader.This dissertation designs a data acquisition and processing system based on DSP for the laser self-mixing interference signal which uses triangle wave current modulation and realizes the acquisition and pre-processing of the laser self-mixing interference signal from PD.The characteristics of the laser self-mixing interference signal and the theory of the vibration measure using laser self-mixing interference signal is analyzed. A data acquisition and processing system which adopts TMS320LF2407A DSP from TI as a central processor is designed.This system has a simple and flexible interface circuit,and it has the characteristics of sample rate being set by software,high sample rate,high sample precision and simultaneous sampling and converting with six channels.The designing and realization plan of system for hardware is proposed in detail,including DSP mini system,DSP and ADC interface circuit,signal conditioning circuit,LCD display module and DSP interface circuit,RS232 communication circuit etc. Anti-interference technology on hardware is also discusssed in the dissertation. The designing and realizing process of system for software is analyzed as followed,which consists of application of CCS,planning of CMD document,data acquisition module,data processing module, pulse width measure module,LCD display module and serial communication module.Practice shows that this data acquisition and processing system can withstand long-term stable operation and fully satisfy the demand on high-acuracy and real-time processing of the high-speed alternating laser self-mixing interference signal.It has a wide application prospect and can develop towards miniature, intelligent and portablevibration meter.