Near field non-standard light source-based in situ obtaining method for three dimensional polishing scratch shapes

Abstract

A near field non-standard light source-based in situ obtaining method for three dimensional polishing scratch shapes is disclosed. Six LED lights uniformly distributed on a hand held microscope are used as light sources, an illumination model for non-standard light sources is built in near field conditions, relative spatial positions of the light sources are calibrated, the hand held microscope isused for collecting image data of worn-out surfaces of parts, a Mask image is obtained based on image processing technologies, images under the same viewpoint and different light sources are subjected to background difference processing operation, an object image which requires three dimensional rebuilding is obtained, and a final three dimensional polishing scratch shape is rebuilt via iterationbased on combination of a technology for estimating a normal direction based on an image sequence and a technology of recovering surface shapes from the normal direction. According to an actual lightsource position, the illumination model for the near field non-standard light sources is built via use of the method disclosed in the invention after photometric stereo visual near field non-standardpoint light sources are adopted, the method can meet requirements of real measurement conditions, and calculation precision of normal vector and depth information of worn-out surfaces can be improved.

Description

technical field [0001] The invention relates to the field of fault diagnosis and state monitoring of mechanical equipment, in particular to a method for in-situ acquisition of three-dimensional topography of parts after surface wear based on a near-field non-standard light source. Background technique [0002] During the operation of mechanical equipment, the interaction between the surfaces of the components forming the friction pair will inevitably cause wear. The material on the surface of the parts that make up the component is continuously lost due to relative motion, leaving wear marks. Studies have shown that under normal working conditions, wear can be divided into three stages, namely, running-in stage, stable wear stage and severe wear stage, and the wear marks on the surface corresponding to different wear states have different characteristics; in addition, according to wear According to different mechanisms, wear can be divided into adhesive wear, abrasive wear,...

AI Technical Summary

Problems solved by technology

Due to the limitation of the volume of the measuring instrument, in-situ measurement of the parts to be tested cannot be realized, and the parts can only be disassembled for measurement, which greatly reduces the efficiency of equipment maintenance

Images