基于自适应SPI总线的列车PIS系统研究

Study on vehicle PIS transmission techniques based on self-adaptive SPI bus

地铁乘客信息系统不仅为乘客提供各类资讯的服务系统,而且在火灾、阻塞及恐怖袭击等非正常紧急情况必须提供报警和疏散提示。针对地铁设备体积小,功耗低的需求,提出基于FPGA+ARM的嵌入式数据采集方案,采用以太网结合SPI总线的传输设计满足了数据采集实时性高,传输数据准确的要求。该方案具有长期运行,稳定可靠的特点。同时还提出采用自适应在线调整采集传输速率的算法,结合贝叶斯网络进行离线训练的算法,对系统功耗控制进行了探讨,取得降低17%功耗效果。

Subway passenger information system （PIS） not only offers passengers various kinds of information, but also, when in an emergency such as a fire, a jam, or a terrorist attack, will provide evacuation instructions. To meet the demand for compact and low power subway equipment, an embedded data acquisition scheme based on FPGA＋ARM was proposed in this paper, whose Ethernet-with-SPI transmission design met very high standards of real-time data acquisition and accurate data transmission. The scheme had the character of long-period operation, stability and reliability. And also an algorithm based on an adaptive online acquisition transmission speed was proposed. Combined with an algorithm util- izing Bayesian network to do offline training, low power consumption of the system was discussed, and the power con- sumption reduced as much as 17%.