Journal of Northeastern University(Natural Science) ›› 2021, Vol. 42 ›› Issue (3): 408-413.DOI: 10.12068/j.issn.1005-3026.2021.03.016

• Mechanical Engineering • Previous Articles     Next Articles

Curve and Surface Fitting Algorithm for Measurement Data

GU Tian-qi, LUO Zu-de, HU Chen-jie, LIN Shu-wen   

  1. College of Mechanical Engineering & Automation, Fuzhou University, Fuzhou 350116, China.
  • Received:2020-08-18 Revised:2020-08-18 Accepted:2020-08-18 Published:2021-03-12
  • Contact: GU Tian-qi
  • About author:-
  • Supported by:
    -

Abstract: The moving least squares (MLS) method is widely used in curve and surface fitting due to its good approximation performance. However, the fitting accuracy is extremely unstable when processing data with gross error.In order to reduce the effect of gross error on the fitting accuracy, a moving least trimmed squares (MLTS)method was proposed. In this method, the least trimmed square (LTS) method was introduced in the influence domain to replace the least square (LS) method, and the optimal group of nodes without abnormal data was selected among all the nodes to determine the local fitting coefficient.Assigning weights or setting threshold values artificially is unnecessary, which avoids the influence of subjective operations. Numerical simulation and experimental data processing showed that the gross error of measurement data can be handled effectively, and the fitting results of the MLTS method are better than those of the MLS method, which has good fitting accuracy and robustness.

Key words: curve and surface fitting; gross error; moving least squares(MLS); least trimmed square (LTS); local fitting

CLC Number: