Research On Two-dimensional Laser Micro-angle Measuring System

Angle measurement is a very important part of measurement technology, which has been relatively complete up to present, and there are plentiful means for detection. The technique of photoelectric micro-angle measurement has the advantages of non-contact, high precision convenient and reliable. It has been widely used in many fields, such as mechanical, aerospace military and so on.Currently, those photoelectric small angle measuring instruments which are widely used are able to meet the actual requirement in terms of accuracy. However, these instruments just could measure one-dimension, and are too large to be taken to some special working site. Therefore, it is necessary to develop a compact and portable high precision angle measuring instrument.Aiming at the problems above, we put forward the basic targets of the research. According to the requirement of response speed, light intensity dynamic range and stability, and comparing the different types of light source and photoelectric sensor, a photoelectric sensor system based on LD (Laser Diode)-PSD (Position sensitive detector) is built. Then, several key technologies for micro-angle measurement are studied based on the laser auto-collimation principle and the original micro-angle sensor.The optical structure is designed first, and the optimization for the light path and optical device structure of two-dimensional micro-angle sensor is completed. By means of coordinate transformation, the coupling of two dimensional angle measurement caused by PSD mounting error is solved. Then, a scheme of using embedded system for data acquisition and processing is designed. The system for signal processing and display is made, and the hardware system is integrated.After the calibration for angle sensor is taken, we have carried out several test experiments of range, linearity, resolution, stability and so on, and the main parameters of the system are determined. At the same time, the control experiment comparing with the photoelectric autocollimator is done to verify the reliability of the system. The results of these experiments show that the subject research has achieved the expected targets.At the last, the work of the whole project is summarized, and the prospects for improvement are put forward.