Research On Detection Technology Of Complex Parts Quality Based On Geometric Error Evaluation

In order to meet the functional requirements of the product,the structure of the parts are becoming more and more complex,the manufacturing enterprise of mechanical processing technology has been rapid developed,it not only requires manufacturing enterprises to adopt CNC machine tools and other advanced equipment for processing,at the same time of machining quality testing technology is also put forward higher requirements,for example,the detection speed,accuracy and cost etc.The process of data acquisition and data processing quality detection technology is complex,it has advantages when detecting simple parts with single structure,but there are many structural features of complex parts,so some problems like the data collection difficulties,limited size exist in the detection process.Therefore,this paper use the 3D laser scanner to collect data,and look at ways of quality detection technology of complex parts,realizes the geometric error evaluation.At the same time it solved the problems that too much Iterative,too much computation,blind of the search direction which exist in the geometric error evaluation optimization algorithm,it ensure the machining parts meet the requirements of design,the production of high efficiency and low cost.The main research contents are as follows:First,this paper study the acquisition approach of the point cloud data,Compare the advantages and disadvantages of contact measurement and non-contact measurement,analysis the working principle and the data of different laser scanner acquisition mode.Compare and analysis on the point cloud data,experiments show that,the distribution of data point is uniform through the hand-held laser scanner.Data collection methods is more flexible than the other scanner,the error is relatively small,Therefore the hand-held laser scanner as the acquisition device of complex parts detection of point cloud data.Secondly,it study the point cloud data processing method of complex parts.Proposed the method of random combined with curvature sampling to simplify the point cloud data based on the reduce the noise processing techniques of original point cloud data and algorithms of point cloud data.This paper research on the point cloud data model and entity model of CAD alignment,including technology based on three point alignment or feature alignment and the best fitting alignment technology.And put forward a hybrid alignment method based on feature alignment method and the best fitting alignment method,according to the features of multi-feature of complex parts.Thirdly,established the position error evaluation model based on the improved colony algorithm.According to the obtained point cloud data,three mathematical models of the cylindricity error,flatness error and spatial straightness error are separately established obeyed the principle of minimum condition evaluation,Aiming at the insufficiency of traditional algorithms in the position error evaluation,different and improved colony algorithm are utilized to calculate and optimize evaluation for cylindricity error,flatness error and spatial straightness error.It is proved through examples.The application of improved artificial bee colony algorithm in geometric error evaluation can solve the problem of the much number of iterations in the operation process and the blind of the search direction,improve the speed and precision of it.Lastly,this paper researched the quality inspection of complex parts.Based on a complex part,to obtain the point cloud data using hand-held 3D laser scanner was scanned.Then remove noise and mixed streamline curvature based algorithm to obtain the point cloud data.So we can fusion feature and best fitting way of registration with the point cloud data after processing and complex parts entity CAD model.In order to carry out the quality inspection of parts conveniently,we use the3 D comparison.Based on point cloud coordinate data,which we get from the corresponding feature extraction of the surface complex parts,we estimate the geometric error of complex parts.Finally,we verify the correctness and the usefulness of complex parts quality inspection and evaluation,which presented in this paper.