An Intelligent Detector For The Dedicated Pressure Gauge Of Rolling-Stock

This thesis studies in an intelligent detector for the dedicated pressure gauge (DPG) of rolling-stock in order to get rid of the defects in the DPG test bed, so that the detector's accuracy can be enhanced.This project is a dedicated and standard pressure gauge of rolling-stock, which is researched according to the special requests of the railway organization, and has a very important effect on the safety of rolling-stock.This detector includes pressure generating device, pressure controlling unit, signal acquisition and processing unit, computer calculating and gauging unit, and results outputting unit.The detector can carry out testing program automatically, which is clear, visual, and easy to operate and store data, by means of man-computer interface. It can decide whether the gauges tested are up to the standard and avoid error caused by operators, and at the same time increase the accuracy. The highly automatic detector improves the working environment and efficiency of operators. It also applies hi-tech computer technology to the test devices, so that the whole automatic operation has been realized. Data acquisition, errors analysis, calculating,results decision, data processing, results printing, storing and transmitting......the wholeprocedure is carried out by software. Using air as its medium has solved the problem that the special pressure gauges can't use oil as its medium, and has made the detector get up to an advanced level in this field.Furthermore, this thesis also does thorough researches on automatic gauge display reading method on the basis of digital image processing, and works out an automatic reading system which can adapt to different pressure gauge. It brings up an idea that building polar coordinates on the dial and calculating the gauge display according to the corresponding position of graduations and the needle. The method of locating the dial center is put forward through searching for the dial edge in a specified area of the image, as well as the method of identifying the thick graduations and the pointer by Hough Transformations. The method reads data fast, and meets the need of data processing immediately.At last, according to the experiment, the theories, methods and techniques are correct, effective and very worth applying.