Papers by Author: Guo Ping Li

Abstract: Surface quality of bearing ball is one of important factors to improve service performance. It is difficult to detect bearing ball surface defects with high precision and low cost by conventional methods. In this paper one new classification method based on optical fiber sensing technology was put forward from the longitudinal section angle. Inspection mechanism of Y-type and coaxial fiber sensor were analyzed, the mathematical models of the two fiber sensors were established and numerical simulations were realized by Matlab software. Influence of optical fiber parameters on light intensity modulation characteristic regulation was studied. Light intensity modulation characteristic experiments were done with specimens of different reflectivity and processing methods. The results show optical fiber sensing technique is an effective method to separate different surface of steel ball with extracting of two parameters displacement and surface reflectivity.

Abstract: Proposed matching method of bag’s images based on straight line features control in this paper. At first, it established a mathematical model of straight line features control theory; Secondly, it collected bags images by use of machine vision systems. It applied the contrast, image binarization, the first order derivative edge detection, dilation and erosion, image thinning, noise remove and other image processing technology and got the edge of the target object image. Next it used the Harris corner detection algorithm to get corners of edge image which is needed by straight linear control theory and achieve the features matching of two bag’s edge images. Finally, it processed vertical, rotating, tilt, moving and light changing’s bags’ images when putting bags stacked and side by side, the results show that the proposed matching method has strong robustness.

Abstract: The constituting of diagnosis expert system and the basic theory of fault tree analysis were introduced at first. A model of combining fault tree with expert system was analyzed. It focused on the hydraulic excavator PC220-7 for Komatsu according to the hydraulic system breakdown of law and order was particularity. A method combined the fault tree analysis with an expert system based rules was adopted. It was expressed systematically expert knowledge by building a fault tree. According to the fault tree, a database of diagnostic rule can be automatically generated. Automatic diagnosis knowledge acquisition has become reality. A hydraulic system fault of excavator was given as an example to design an expert system with the function of complex reasoning and explanation. It provides a reference for hydraulic excavator of the use of management and fault maintenance personnel to solve excavator problems. It shows that this method has a good application in the future.

Abstract: The pressed protuberant characters on metal label are the difference of reflectance. It is very difficult to obtain the character of full binary image directly. It has presented a novel method of image acquisition on metal label pressed protuberant character based on moiré contour. At first, the principles of moiré contour were analyzed; Secondly, the experiment parameters were designed by using of shadowing moiré equipment and pressed characters’ height. The moiré image of metal label is captured through experiment by using of CCD camera. The binary image of pressed characters was output using moiré fringe image modulated by the characters’ height as input image contrast enhancing, complement, middle filter, automatic threshold etc. The binary image of pressed character was obtained using image preprocessing. At last, the binary images of moiré contour obtained and direct obtained were compared. The experiments show that the binary image of moiré contour obtained is better than direct obtained image.