Evaluating freeform curve profile error based on improved genetic algorithm and quasi random sequence

Autor: 朱晓春 Zhu Xiao-chun, 赵艺兵 Zhao Yi-bing, 曹未丰 Cao Wei-feng, 王东霞 Wang Dong-xia, 温秀兰 Wen Xiu-lan
Rok vydání: 2012
Předmět:
Zdroj: Optics and Precision Engineering. 20:835-842
ISSN: 1004-924X
DOI: 10.3788/ope.20122004.0835
Popis: An evaluating method of freeform curve profile errors based on the Improved Genetic Algorithm(IGA) and quasi random sequence was proposed to inspect freeform curves and surface parts and to compute their profile errors efficiently and precisely.Firstly,according to the characteristics that the freeform curve was expressed by discrete points rather than an analytic function,the Non-uniform Rational B-spline(NURBS) was used to express the free curve and the IGA was proposed to reconstruct it.Then,the quasi random sequence was taken to generate parameter values uniformly and to calculate the shortest distance from a point to a reconstructed curve exactly.Furthermore,The computation methods of the control vertex and objective function value were described when freeform curve was reconstructed and the detailed steps were established for reconstructing the free curve and computing the shortest distance from the point to the curve based on the IGA and quasi random sequence.Finally,the curve profile errors of a simulation example and practical parts were calculated and measured.The results verify that the evaluation precision of freeform curve profile error is higher than 99%.The proposed method has the advantages of simple algorithm,rapid computation and high accuracy and it can be applied in engineering metrology.
Databáze: OpenAIRE