The Design And Realization Of The Harmony Type ¢ñ Electric Locomotive Braking System Monitoring Unit

Since its operation in large scale, HXD1 electric locomotive has made a substantial increase in China's heavy-load railway equipment. However, over the past two-year operation, the abnormal brake phenomenon has emerged repeatedly on the locomotive, so it turned out to be insecure. In order to find out causes of abnormal brake so as to ensure safe operation of locomotives, a monitor unit of locomotive braking systems is in need. This paper puts forward an overall design program based on the FPGA-chip integration multi-protocol technology after an in-depth study of heterogeneous multi-protocol networks HXD1 electric locomotive control system, combined with the function need of brake system monitor unit.In the design of the hardware, trigger-based all-digital phase-locked loop approach was uesed to resolve the asynchronous problem in communication due to the strong electro-magnetic interference. We ensure the bit synchronous digital signal through digital phase detector, and filters quantitative calculation of the local network signals and locomotives of the phase error signal to drive the local osci(?)ator signal phase adjustments. The memory bus to the time-division multiplexing method is proposed in the light of compatible multi-protocol for communication in shared memory problem of concurrent access to the conflict. Through the establishment of a multi-communication interface memory to visit the conflict model, the phase-shift parameters to the time of the communication interface is assessed so as to obtain time-division multiplexing parameters of the conflict under the minimum access.When it comes to the software design which aims to erase the computing constraints of CPU, in accordance with characteristics of data transmission of locomotive, the data model update algorithm is suggested based on the cycle phase. The relevance of the data strength of braking will be assigned to the update cycle, data cycle phase different priorities for a visit. Non-periodic data updates to the incident are searched through the improved binary search algorithm. Guarantee real-time data access.Finally, we make a detailed description of the realization of the hardware and the software in the system. The brake monitoring system has been installed on Hudong harmony Locomotive Depot on I-electric locomotiv at the Taiyuan Railway Bureau, the testing proving the feasibility and effectiveness of the design.