Research On Collimation Measurement Based On Laser Interference Technology

With the development of modern science and technology, people call for a higher measurement accuracy of geometric parameter. Straightness measurement is one of the most basic geometric sense meterages, as well as the familiar and important measurement item in the machining process. It also has widely application in fields of precision instrument manufacture and examination, large scale measurement, the fixing and localization of large instrumental and the manufactory of the war industry product.This paper studies the history and actuality of laser collimation technology. Using the predominance of laser interference technology and combining modern sensor technology and digit signal processing technology, it brings forward the laser interference collimation system based on the wedge-shaped plate interference. This subject has finished the design of collimation optical path, as well as the design and debugging of the measurement system based on the PIC microchip. Through a great deal examinations, this system can well accomplish the straightness measurement. It has the characteristic of miniaturization, low consumption, low cost and portable.The main work of this paper includes:1.The principle of analysis and collectivity design of the laser interference collimation system, including the editing of gross structure, the choice of optical source and photoelectric elements and the design of the machine structural,processing program of signal and so on.2.Signal acquisition and debugging. Photoelectric Singal is feeble and esay to be interferential. According to these characteristics, the paper finishes the debugging from photoconducting device choosing to the adjusted artificial circuit design.3.The circuit design based on PIC singlechip. This system chooses the singlechip PIC16F877 to be the processor , which possesses the ability of high speed data processing and 10 channels A/D module. It also designs a system which is used to conversing signal and processing data.4. Analysis and Design of data processing method and software subdivision. Contraposing the characteristic of the interference fringe signal, the paper thoroughly investigates signal process technology, designs the signal process software and the software subdivision means for counting interference fringes. Compiles the arithmetic codes based on MATLAB, analyzing and fitting the measurement data, assessing the straightness error.