Ding Caihong

Segmentation of color image contour using fuzzy cluster analysis

Segmentation of edge contour is an important part of color image processing, however the existence of gradual change of color and edge scatters will badly affect the result of image processing. A classification algorithm based on fuzzy cluster analysis is put forward in this article for segmentation of edge contour. On the basis of the color aberration analysis in HSI color space, fuzzy similarity matrix is constructed and then made equivalent. Combined with the transitivity character of fuzzy equivalent matrix, the algorithm is further improved by adding special constraint conditions according to the characters of sudden change of edge scatters in the small-scale area. The algorithm is proved valuable and effective by experimental analysis to well solve the problems of colors gradual change and edge scatters, and to get good result of color image processing.

Design of a Level Attitude Auto-Adjustment Controller for Joint-Tracked Mobile Robot

Considering the mechanism characteristics of the joint-tracked mobile robot, a controller based on real-time feedback is put forward to accomplish level attitude auto-adjustment. After analysis on kinemics and dynamics, the controller model is supposed which takes several kinds of sensors as detecting elements, kinemics and dynamics models as reference to build decision strategy. And an open control system based on DSP and industrial computer is adopted for the controller. It is proved to satisfy the demands of level attitude adjustment through climbing and obstacle negotiation experiments.

Analysis and Improvement Method of the Dynamic Response of Electromagnetic Clutch Used in the Tufted Carpet Jacquard

For a tufting machine, the electromagnetic clutch is required to be switched frequently and response quickly during the jacquard process. By the analysis on the effect to the jacquard process of the response characteristic of electromagnetic clutch, it shows that the torsion rising time is a main factor affecting the difference of yarn feeding and the quality of tufted carpet. An improvement method of the dynamic response of electromagnetic clutch is proposed in this paper. In this method, Taylor series expansion is used to get the exciting voltage curve, then the current response is accelerated and the torsion rising time is decreased by varying the exciting voltage of the clutch. The modeling and simulation of the method is processed by MATLAB/SIMULINK. Then a single-chip system is designed to achieve the exciting voltage by PWM. The results of the simulation and experiment show that the response of the clutch is more quickly and the current response is more steadily. High quality tufted jacquard carpet is produced by the application of this method.

Vectorizaiton of lattice diagram based on straight line and circular arc fitting in variable-step

Vectorization of the lattice diagram after contour segmentation is a critical techniqure to keep tufted carpet from destortion in the process of manipulator-tufting. A new algorithm is put forward to realize the vectorization, and keep the fitting error in an allowable range. The process of curve vectorization includes several steps: Form a feature point set by extracting the Freeman chain coding feature points from the pixel points of the image, then run straight line fitting and circular arc fitting in variable-step, and finally obtain the contour curve represented by linear and arc equations. The algorithm in this paper is mainly used for carpet image recognition and transfer in a manipulator-tufting system. Through VC++ programming of the algorithm and then repeated experiments, it is proved that the algorithm is effective, feasible and quick to especially satisfy the requirement of high efficiency.

A prototype of fault diagnosis based on Petri nets

A Petri net modeling tool using the object oriented method is introduced in this paper. With this tool, a Petri net-based prototype of fault diagnosis was developed using the model-based method. The prototype was connected to the database by DAO technique, and the firing mechanism and analytic methods of Petri net were used to form the DLL documents. Compared with the method of rule-based expert system, the Petri net-based one has the following advantages: 1) with direct knowledge representation; 2) with convenient knowledge storage in a form of mathematical matrix; and 3) making inference more quickly and effectively.