A Wheel Profile Fitting Method based on Discrete Points Weights of Wheel Tread Profile of Automatically Extracting Subsection Points

Qianyi Yu

Nanjing University of Science and Technology, Nanjing, 210094, China

Abstract: In order to better fit the contour of the wheelset tread, a method for fitting the contour of the wheel contour based on automatic segmenting by the weight of the contour point of the wheel tread was proposed. Firstly, the discrete points of the wheel tread contour were measured by the laser displacement sensor, and their weights were defined according to the importance of the scattered points. Then, the variable fitting iterative step size and error bounds were set to determine the piecewise points and the fitting function. The Lagrange multiplier method is used to solve the problem. The contour lines of each section of the wheelset tread with smooth connection can be obtained through the simulation fitting algorithm, which can be used in the fitting of the contour lines of the wheel tread with improved fitting accuracy and efficiency.

Keywords: Urban rail transit; Wheel set tread profile; Automatic piecewise fitting; Weight function; Lagrange multipliers