A Study Of Guide-Ways Linearity Measurement Based On Image

Straightness measurement is one of the most basic and important item in the field of geometrical measurement, which is the basis of planar degree, parallel degree, orthogonal degree, coaxial degree and ect. As one element of the form error, straightness will affect the form and dimension accuracy of the processed accessory during the movement of guide-way.Traditional straightness measurement, such as leveling rule, gradienter, reinforcing wire, even though simple in detecting apparatus and adopted widely, are of certain limitation, low accuracy, low efficiency, and can't guarantee the performance. On the other hand, some other measuring devices cannot be widely used because of value. As a result, we take the straightness measurement of guide-way as object of research, and advance a method based on digital image processing to measuring straightness on the premise of accuracy and economics.Reasonable baseline is one of the key matter in the straightness measurement. Two schemes of the measuring basis are advanced in the paper--tensile spring and laser beam, based on the request and character of guide-ways straightness measurement. In early study, we come to the conclusion by theoretical analysis and experiment that the laser beam basis has more advantage in development and accuracy. On the basis of the analytical result, straightness measuring system based on the imaging processing and laser beam are studied primarily. In the detailed design, inverse drift compensating system is advanced to solve the problem of laser beam drift, which is farther verified by the experiment. The software can get the straightness error data by image acquisition, gray scale transformation,filtering, thresholding and target recognition. The paper designs a measuring system which employed image technology, computer technology and data processing.After theoretical analysis, system construction, experimental verification and error analysis, the paper argues that the method has fair value for practical use, and advance perfecting ideas. So it is worth for further research and development.