Research And Design Of The Locomotive Wireless Data Transfer System

In conventional railway operation mode, the recorded information about the locomotive is available to management after it stops at a station and the IC card is fetched to get the information data. This, however, can no longer suffice due to the fast development of modern railways and various new requirements proposed. There is a demand that the locomotive information be sent to management timely.In order to cope with the problem, we designed a locomotive wireless data transfer system. The system monitors the locomotive's present situation and sends it to the railway management, then the ground expert group will give advice to locomotive engineers based on the information, and help them deal with emergency situations or diagnose breakdowns.The focus of the paper is on the design of the hardware of the locomotive wireless data transfer system and its lossless data compression and error correction coding. In chapter 2 the locomotive wireless data transfer system's overall design is introduced and its functional modules are discussed respectively; in chapter 3 we go into detail on the on-board equipment, proposing designs for each functional module. The on-board equipment has a STC12LE5410 microprocessor as its core control unit, using SPI bus to connect with IC card to read the specific files from it and send the processed data using the GPRS wireless module; in chapter 4 we discuss both the on-board system and ground data center server's software designs. As data in IC card are conveniently compressible, thus economizing on GPRS network channels, LZW compression is introduced to accomplish this task and CRC is also included to guarantee the reliability of the data transfer process. Coding algorithm is optimized to simplify the program and reduce operations as well as storage space, so its speed is improved to better satisfy real-time requirements of the communication. The MC52i GPRS module is adopted, and its embedded TCP/IP protocol stack is used to transfer data. In the end, we test the system and give our analysis on the results.