Research On Digital Inspection And Assessment Algorithm Of Flatness Errors

With a new generation of information technology, Internet technology, digital manufacturing technology such as intersection of multidisciplinary technology, advanced manufacturing technology obtained the rapid development, aerospace, medical equipment, precision instruments and other industries has higher requirement on the quality of the product. Geometric errors have a direct effect on mechanical product quality, accuracy, or the use of performance; Flatness error is one of the most common geometric error, and the measured plane elements are almost neither parallel nor vertical space general position plane with the three-dimensional coordinate axes; Flatness error evaluation of general location for the space, the existing evaluation algorithm has some limitations. So research the flatness error evaluation of general location for the space in digital detection and assessment has an important theoretical significance and engineering application value.In this paper, the main research work is as follows:(1) This paper expounds the flatness error detection and evaluation of the background, significance and research status; Summarizes the flatness error evaluation theory, the LSM (Least Squares Method, LSM) and so on the many kinds of algorithms are analyzed, and illustrates the algorithm was applied to the flatness error evaluation of the general location, has obvious limitations; Therefore, the Three Dimensional Least Squares Algorithm (3DLSA) is put forward, and the mathematical model is established, its validity is verified by the digital experiments.(2) Taking into account common evaluation method of flatness error, only two points contact area does not meet the minimum standards, cannot be used for the high precision of detection and evaluation of flatness error; Therefore, MZCA Algorithm (A new Algorithm based on the Minimum Zone Criterion, MZCA) is put forward, the mathematical model and the algorithm flow chart of MZCA algorithm are given, and the digital experiment shows that this algorithm is a good algorithm which can achieve 3 or 4 contact and has a high evaluation precision, the accuracy of the evaluation can reach nanometer level.(3) Based on the operation of a new generation of GPS technology, using three coordinate measuring machine was carried out on the flatness error of a flat parts digital detection, have had the flatness error measuring point set. Aiming at the measuring point set, respectively by 3DLSA algorithm, MZCA algorithm solving the flatness error value, in order to realize the three-dimensional digital flatness error detection and evaluation of technical operation, verify the validity of the two algorithms.To sum up,3DLSA algorithm can satisfy the requirement of accuracy in the engineering practice, the general digital detection and evaluation, implement general position approximate evaluation of flatness error; MZCA algorithm can realize precise flatness error evaluation, and can satisfy the general location to the space in the manufacturing engineering of digital flatness error accurate assessment requirements. Therefore, this paper studies the digital flatness error evaluation algorithm in manufacturing has important engineering application value.