Research On High Accuracy Inspection Of Train Wheel-set Journal Diameter

Currently, the method of inspection by vernier caliper is used when train wheel-set is measured in our country. There are many factors that lead to not meeting the great efficiency, high accuracy and short measurement periods at the same time, such as randomness and inefficiency. The new method is sought with future for dynamic inspection of train wheel-set parameters. The parameter of journal is difficult to inspect in comparison with the other components of wheel-set because the structure of train wheel-set needs the accuracy reach±0.002mm, more two magnitude than others.Based on analyzing existing methods, the way of projection is ascertained to inspect the abrasion of train wheel-set journal. The laser bean that is collimated and diffused irradiates journal, then images on sensing elements of linear array CCD (charge coupled device) through imaging system. The place that is irradiated by laser bean would be moved if the dimension of journal changed. Compared with the position scaled beforehand, the abrasion value of journal is measured. The wear and tear status of train wheel-set journal is known.In this paper, the feasibility of this measuring is analyzed in the first place. The way of data processing of correlative parameters is suggested. Some factors that impact on the precision are also discussed. The means of error compensation is propounded. On this condition, the designing and debugging of the high accuracy inspection system of train wheel-set journal are accomplished. The circuits designed are as follows: driving pulse circuit of linear array CCD, signal processed circuit, interface circuit communicated between microcontroller and PC. And the software projected is as follows: driving program of linear array CCD, program of microcontroller sampling and sending, program of PC receiving and processing. The system debugging and the result indicate that circuits designed and software projected is achieved anticipative objective. The system works steadily, so the reliability of this method is proved.