Method to improve evaluation accuracy of radius of 
curvature parameters of non-holonomic arcs


LUO Zhi-sun1, WU Guo-xin1, HE Xiao-mei2, HE Xue-jun2, ZHU Chun-mei1

(1.Key Laboratory of Modern Measurement and Control Technology, Beijing Information Science and Technology University, 

Beijing 100192, China;2.Changcheng Institute of Metrology and Measurement, AVIC, Beijing 100095, China)


Abstract:  Aiming at the problem that the poor integrity of the small arcs in metrology led to the low accuracy of the parameter evaluation of radius of curvature, a method based on an adaptive cubic exponential smoothing prediction model was proposed to increase the center angle of the contour data point set, thereby improving the evaluation accuracy. Firstly, the influence trend of the central angle of the small arc on the evaluation process was analyzed by simulation. According to the results of the simulation analysis, a method was proposed to add an adaptive optimization algorithm based on the cubic exponential smoothing method, which solved the problem that the best smoothing coefficient was difficult to determine in the prediction process, and optimized the traditional prediction model and the selection criteria of various parameters. Finally, a number of control experiments were carried out, and the effectiveness of this method was verified by combining the experimental results. The experimental results show that for the non-holonomic small arc profile data point set with the central angle below 60°, it is best for the evaluation process to use this method to expand the central angle by about 5°, which can also be used as a preliminary data processing method, and combines different evaluation methods to improve the evaluation accuracy with varying degrees.

Key words:  metrology;non-holonomic small arc;parameter evaluation of radius of curvature;cubic exponential smoothing; adaptive optimization algorithm

LUO Zhi-sun, WU Guo-xin, HE Xiao-mei, et al. Method to improve evaluation accuracy of radius of curvature parameters of non-holonomic arcs［J］.Journal of Mechanical & Electrical Engineering, 2021,38(9):1138-1144.