摘  要

在铁路运输生产中，大屏幕对于提高其运营水平起着至关重要的作用。DMIS（行车调度指挥系统）需要用大屏幕将各线路上各列车的运行状况直观、实时地表现出来，使调度人员如身临现场，高效地安排运输生产。结合LED高亮、发光均匀、节能等的优点，LED大屏幕构建灵活、可视角好及向更高发光密度、全彩高清化等的发展趋势，本文讨论并构建了适应铁路行车指挥调度的LED大屏幕显示系统。

针对铁路行车指挥调度显示系统监控面大、实时性高的特点，论文研究讨论了基于铁路沙盘的LED大屏幕行车监控模拟显示系统构建：根据屏幕显示时间与输出速度的分析，设计各硬件电路模块；建立铁道信号的存储模型，实现信息图像到数据存储的转换；编写各底层模块，并解决运行显示任务与进行存储器数据更新时对MCU的占用矛盾，实现刷新与显示同步。

文中重点阐述了基于SPI的驱动模块及可扩展RAM模块设计，利用SPI方式与计数器组结合，改变了RAM数据的读取及输出形式；通过控制信号的同步与复用，大大压缩了数据读取至输出到屏幕显示的时间。此方式的运用满足了屏幕显示面积的要求，保证了显示内容的实时刷新，解决了显示时输出速度的瓶颈问题。

论文方案已在峨眉校区铁道信号实验基地中得到实现，这为该方案的改进及后续与行车监控模块的融合工作打下了基础，为对LED大屏幕在调度指挥系统中应用的深入研究提供了良好的平台。

Abstract

Large-screen plays a vital role in improving the operation level of railway transportation. In order to give the operator the feeling of in the real environment and let them schedule the transportation efficiently, DMIS（Dispatching Management Information System） requires Large-screen to exhibit the operation conditions of every line directly and real-timely. Concerned about the advantages of high brightness, uniformity luminescence and higher luminous density, LED presents a development trend of flexible construction, certain view angles, higher luminous density, and full-colour and high clearness. This article explores LED large-screen display system, which is applied to train dispatching and controlling.

By consideration of the characteristics of DMIS, the thesis mainly discusses the construction of LED Large-screen Simulated Display System in monitoring of railway operation based on rail sand table. The thesis designs the hardware circuit modules by analyzing the display speed and output speed in the screen, builds the railway signal storage model and achieves a conversion from image information to data storage. In addition, this paper draws the bottom modules and solves the problem that MCU is occupied simultaneously while displaying mission and updating the storied data .Thus the display and update of mission can be carried out synchronically.

And this paper mainly interprets the driving module and scalable RAM module design which is based on SPI. By means of SPI and Counters, such a design changes the read and output forms of RAM data. And by controlling the synchronization and multiplexing of signal, it shortens the time used in reading and displaying the data in the screen greatly. This method meets the requirement for the screen’s display area and ensures that the display content can be renewed real-timely. Therefore, the bottleneck problem on output speed while displaying is solved.

This scheme has been carried out at railway signal lab in E’Mei campus, which lays a foundation for the fusion with control and monitors modules as well as other follow-up improvements, and offers a platform for the further research of LED large-screen in dispatching and controlling system.