The Development Of A Portable Switch Machine Tester Based On Embedded Operating System

Switch machine is one of the most important devices in railway track switch equipment. It is mainly used to pull and lock the railway switch and plays a key role in the safety of railway transport. As a consequence, a portable switch machine tester based on embedded operating system has been designed in order to examine the function of railway transport on site. This machine is used to real-time monitor the output power and working current of electric switch machine in the working status, and in turn to help the railway staff estimate the working state of the switch machine timely.In this paper, the design and development process of all hardware and software was demonstrated based on real-time Linux operating system and graphical user interface in portable switch machine tester. Firstly, the overall design was put forward based on the working condition and data accuracy. And then, every part of this work was finished including the design of hardware circuit in the various working module, the transplantation of operation system, and the development of the software system. Finally, the simulation experiment was carried on to evaluate the control accuracy, stability and response speed.To improve the efficiency of data processing, the portable switch machine tester was equipped with Samsung S5PV210 processor with an inner core of ARM Cortex-A8. The processor is integrated with 32 KB first level cache register and 512 KB second level cache register, and also provides 93 interrupt signal, thus it absolutely meets the data processing requirements. A LCD touch screen with a resolution of 800 x 480 was equipped to real-time display all the data which is convenient for the observation.To design the software, the real-time Linux operating system was firstly transplanted to ensure the stability and timeliness of the tester. Secondly, the QT graphical interface application was transplanted to write and display the operation interface. And then the drivers were written for every part of hardware, and operation interface was reserved for the application. Finally the multi-thread procedures of each module were written to make sure that every module of tester run altogether.In the end, the tester was examined based on the sensors static characteristic experiment and ZD6 electrical switch machine test. The results show that every module of the tester meets the design requirements and the data accuracy of measurement is controlled within the scope required. The tester works stably and meets the technical requirement of on-site test.