Research On Multi-parameter Measurement System Based On Photoelectron Autocollimation Technology

In order to speed up the development of manufacturing industry,high precision computer numerical control(CNC)machine tools were taken as an important field in the "Made in China 2025 Plan" in 2016.However,the machining accuracy of CNC machine tools is restricted by the manufacturing process of CNC machine tools.In addition,the machining accuracy will be also affected by the distortion of components in CNC machine tools.Currently,there are two main aspects to improve the machining accuracy of CNC machine tools.One method is optimizing the structure design,machining and assembly process;another is based on effective error detection and error compensation technology.The most direct and effective way to improve the machining accuracy of CNC machine tools is to optimize the manufacturing process.However,it is difficult to achieve an obvious increase in a short time owing to the current processing and assembly processes.Therefore,an effective error detection and error compensation technique is needed to improve the machining accuracy of CNC machine tools.In order to solve the problems of cumbersome error detection method,high detection cost and low efficiency,this paper proposes a geometric error detection method with low cost,high efficiency and free range expansion.The specific works are as follows:1.After analyzing the advantages and disadvantages of existing geometric error detection methods,a method for multi-parameter measurement based on a combined surface reference and slope detector was proposed.2.The optical path design of the measurement system is finished,the model of the photoelectric detector and the measuring light source are adopted.According to the preset index of the measuring system,the surface characteristic parameters of the reference parts,the measuring range and the resolution of the measuring system are calculated.In addition,considering the problem of small range of single reference parts in practical applications,an expandable large-scale measurement scheme is designed.3.Based on the analysis of the energy distribution and shape characteristics of the facula image captured by CMOS image sensor,a Gaussian two-dimensional surface fitting algorithm is proposed for facula location extraction.The accuracy and stability of the spot location detection of this algorithm are verified experimentally.4.The calibration and measurement experiments of the system are completed.The calibration work was mainly about the installation error of l-type array and slope detection system.The measurement work mainly verified the accuracy,repeatability and stability of the system for angle and displacement measurement.Then,the factors affecting the measurement accuracy of the system are analyzed according to these results.