The Research And Exploitation Of Air Compressor Test-bed Based On PLC

The unceasing speeding up and improvement of the transportation capability of our national railway arouses more demand for the security of train. Air compressor machine is mainly used for brake in locomotive cars. The capability of the air compressor directly affects the safety of locomotive car's move. According to the examining and repairing rules of locomotive, we have to do some performance experiments in air compressor test-bed. The old test-bed has many shortages, such as: the data of experiment can't restore in time, the function of system is singleness, it needs a lot of instruments to test at many times, and the whole experiments cannot finish in one test-bed at one time, etc.With the development of the modern control, PLC and embedded touch-screen's technology is coming to maturity and its price is lower. For this, PLC and embedded touch-screen are widely used in many kinds of situation, such as electric, metallurgy, transportation, etc. PLC can be programmed easily, and it has high degree of modularization, also its function of network-communication consummates increasingly. Embedded touch-screen has many advantages, such as easy to operate, having direct interfaces, saving space, and its method of programming is flexible, so it is becoming main input unit used in embedded computer system instead of keyboard. We intend to design a new test-bed using PLC, embedded touch-screen, transducer, etc. It cans not only using manual function to do one step of the experiment of air compressor, but also using automatic function to finish all the steps of the experiment at one time. The using of this test-bed makes examining and repairing of air compressor's accuracy and efficiency higher, accordingly more insures the security of locomotive's operation.This paper's background is on the project of designing a new supervision and control system for air compressor machine in Datong locomotive depot. In this paper , writer has exhaustively illustrate the integer process of designing from several factors, such as: choosing the fit hardware, designing the communication network, designing the circuit of control cabinet, the system of configuration, programming of PLC, designing the functions of touch-screen, etc. We first introduce the structure of air compressor, the process of the test-bed's design, and the chose of device, then we analyze with focus on the design of the hardware and software of our air-compressor test-bed. The hardware contains the form of test bed's parts and their function, the communication of different equipments, and the working flow of the whole system. The software contains the structure of PLC's program, the exploitation of configuration software, the realization the function of data printing, the problems we faced in debugging and how to solve them. In the end, the paper introduces the circumstances of locale and the measure we taken to enhance the on-the-job dependability of the equipment.