Research On Geometric Error Measurement System Based On Compound Feature Surface Array

As the fundamental tool machine of equipment manufacturing industry,the processing accuracy of CNC machine tools represents the level of a country's manufacturing industry.With the development of China's economy and the progress of science and technology,the number of CNC machine tools in the country is increasing year by year and high-tech manufacturing field also ask CNC machine tool processing accuracy for higher and higher requirements.How to improve and maintain the precision of CNC machine tools has been the focus of precision manufacturing research.Geometric error measurement and compensation technology,which has been widely used,has a significant effect to improve the overall machining accuracy of the machine.In the face of increasing volume and increasingly accuracy of error compensation needs,how to achieve geometry error measurement more efficiently and accurately has become one of the key issues.In this paper,the geometric error measurement method based on the compound feature surface array is studied.The main work is as follows:1.According to the classification of geometric error of NC machine tool,the measurement principle of different geometric error parameters is analyzed.A 5-DOF geometric error parameter simultaneous measurement system is proposed by designing optical probe and composite feature surface reference parts.The measurement model of the system is also proposed.2.The whole structure of the measurement system is designed.The semiconductor laser is selected as the measuring light source of the system.The characteristics of the imaging spot in displacement measurement are analyzed.The displacement measurement is carried out by using the focusing beam to improve the quality of the light spot imaging.The mechanical design and prototype build of the optical probe,integrated reference parts array and modular teference parts array are completed.3.In order to solve the problem of position extraction of angle imaging spot and displacement imaging spot in measurement system,the evaluation method is analyzed.The accuracy and stability of different spot position extraction methods are verified by digital image processing technology.Finally,high precision extraction of the image spot position is completed by centroid method.4.The calibration experiment and test experiment of the system are completed for the designed measurement system.The calibration method of L-type composite reference parts in the displacement measurement is proposed and displacement measurement,roll angle and the function test on L-type composite reference parts.It is proved that the measurement system has a good measurement effect on a single composite face reference element,and the reason of the error on the composite reference is analyzed.