The Study On The Anti-background Light Techniques Of The Photoelectric Autocollimator

Most Autocollimators are used indoors without the sun and incandescent lamp interference, so they can reach the precision index. While if a Autocollimator is used in outdoor environment, it will be faced with many kinds of interference, such the sun and so on. It will lead to lower accuracy, what’s worse, the autocollimator may work anomaly. So it is significant to study anti-jamming technology and improve anti-jammingcapability of the Autocollimator.The main idea of this article was how to improve the resolution and the accuracy of the photoelectric autocollimator system with back light interference. It was based on over all study of the working principle and the advances of autocollimator at home and abroad. Finally, we choose the anti-jamming techniques of the autocollimator based on optical modulation as our solution. What’s more, study of design of optical system, analysis of e xtra light and study of algorithm was chosen as our starting point, and then relative the theoretical research and experimental verification was done. So far, some progress was made as follows:1. Considering the back light, parameters of the optical filter, photoelectric detector, bore of lens based on the existing optical system autocollimator. Finally the influence of the back light on the accuracy of the photoelectric autocollimator was analysis with Tracepro. The conclusion was drawn: The larger the angle of incidence, the less back light received by CCD.2. The anti-jamming technique of the autocollimator based on optical modulation was advanced and proved by software nodal based on MATLAB. The result shows that the SNR of output signal was raised up 11.38 db. The data processing software was programmed by Lab VIEW. Finally, seven sets of experiments were designed. After the background subtraction anti-jamming techno logy used, the measuring accuracy is no obvious change compared with the former; outdoor environmental conditions, with and without the background subtraction method for anti-jamming technology self quasi straight instrument compared, can normally measured in the background light is stronger.