摘要
设计了一套基于嵌入式的城市轨道交通GPS(全球定位系统)时间服务器。系统硬件采用GPS OEM板和ARM9开发板,并在开发板上增加了Zigbee无线传输模块和扩展了的RS 485接口,可满足城市轨道交通时间信息传输多样性的要求。通过分析网络时间协议(NTP)的基本原理,设计并完成了嵌入式Linux下的服务器程序和Windows下的客户端程序;客户端程序采用Windows系统内部的高精度定时器,提高了时间分辨率,可以使局域网内计算机的授时精度达到微秒级。利用真实的网络环境对其进行测试,结果能够满足城市轨道交通行车控制和运营管理的特定要求。
An embedded GPS time server for urban mass transit is designed, which uses GPS OEM board and ARM9 development board, but increases the Zigbee wireless mod ule on the development board and the expanded RS485 in terfaces to meet various demands for the transmission of time information in urban rail transit system. In this paper, the basic principle of Network Time Protocol is analyzed, the server program under the embedded Linux and the Windows client program are designed. To improve the time resolution, the client program adopts the high precision timer within Windows system, which can improve the time resolution and achieve level of computer timing accuracy within LAN. Finally, a real network environment is used for a test, and the result shows that this time server could meet the specific requirements of control and operational management for urban mass transit.
出处
《城市轨道交通研究》
北大核心
2013年第4期24-27,43,共5页
Urban Mass Transit
