The Software Development Of Spatial Straightness Error Measuring Equipment Based On Non-diffracting Beam

The straightness error measuring technology is widely applied in the fields of manufacturing machines, installing precise equipment, testing great dam deformation, fixing high-speed rails, etc. The non-diffracting beam is a perfect straight datum line for its character of high optical density central spot, slightly exhaling, good stability and so on. Therefore, the non-diffracting beam technology is applied in the straightness error measurement. The non-diffracting beam spatial straightness error measuring instrument is an example, which combines the non-diffracting beam technology and CCD (Charged Coupled Device) imaging technology, uses the non-diffracting beam as a straight datum line and realizes the straightness error continuously measurement.The goal of this dissertation is developing a software system on the foundation of the non-diffracting beam spatial straightness error measuring instrument hardware with analyzing demand of the measurement system.There are three parts in the software system, including the image showing and collecting, image processing, and the straightness error evaluation and output. The image showing and collecting part, developing on the software packages which provided by the image collecting card, realizes the image showing and collection function. Using the fingerprint image enhancement algorithm, the concentric rings'center coordinates are obtained with the improvement Hough transformation in the image processing part. In the straightness error evaluation part, the straightness error evaluation of the assigned plane and the assigned direction beeline is calculated precisely with three kinds of evaluation method, two endpoints method, least squares method and minimum zone method ,the digital results and the erroneous diagrams are exported in this part.This dissertation took the lathe linear guide as a research object, two experiments were made between the straightness error measurement system and HP-5528A laser measurement system, and the result indicated that this measurement system met the foregone precision demand. The installment of the linear rolling guide was taken for an example to explain the application of this measurement system in practice. In this example, the linear rolling guide was adjusted according to its survey data and its linear precision was improved. Finally, the summary and the forecast of the research work are proposed, the problems and the improvement advices of this system are discussed too.