基于PCIe级联网口的农业监测视频高速传输系统研究

High-speed Transmission System for Agricultural Monitoring Video Based on PCIe Cascaded Network Interface

农业监测智慧化需要实时、高效、可靠的视频数据处理和传输方案,为了解决传统基于CPU和GPU架构的系统速率低、实时性差的问题,设计了基于Zynq架构的PCIe级联网口的高速传输系统。针对PCIe接口开发,在硬件层面,优化配置XDMA IP核参数,完成接口的数据收发引擎设计,并基于MIG 7 IP核优化配置了DDR缓存区。在软件层面,基于PCIe驱动,调度VLC软件完成视频数据读取,实现板卡和上位机之间数据的快速收发和流畅播放。针对网口协议栈的实现,利用ARM可编程特性,调度LWIP轻量级协议栈,完成TCP协议的开发,实现了网口的数据快速收发,避免了上位机CPU直接处理网络协议的时延和运算开销。此外调度AXI协议完成PCIe接口和网口的高速连通。在Zynq MZ7030FA平台上传输视频文件对系统进行速率和可靠性实测。结果表明:网口传输速率达800 Mb/s,基本实现了千兆以太网;PCIe接口的最高传输速率达816 MB/s,逼近硬件PCIe 2.0 x2的最高速率,且整个系统在应用层上实现了可靠传输。本文的研究为农业监测视频传输应用提供了高效可靠的解决方案,且系统具有较好的扩展性和推广性。

The intelligence of agricultural monitoring requires real-time,efficient and reliable video data processing and transmission solutions.In order to solve the problems of low rate and poor real-time performance of traditional systems based on CPU and GPU architecture,a high-speed transmission system based on Zynq architecture with PCIe cascaded network interfaces was designed.For the development of PCIe interface,at the hardware level,XDMA IP core parameters were optimized,the interface data transceiver engine was designed,and DDR cache area was optimized based on MIG 7 IP core.At the software level,the PCIe driver was used to schedule VLC software for video data read operations,enabling fast data transmission and smooth playback between the board and the host computer.For the implementation of the network interface protocol stack,the ARM programmable feature was utilized to schedule the lightweight LWIP protocol stack and develop the TCP protocol,achieving fast data transmission for the network interface and avoiding the delay and computational overhead of the host computer CPU directly processing network protocols.Additionally,the AXI protocol was scheduled to establish high-speed connectivity between the PCIe interface and the network interface.Moreover,the rate and reliability of the system were also measured by transmitting video files on Zynq MZ7030FA platform.The results showed that the transmission rate of the network interface was 800Mb/s,that was,gigabit ethernet was basically realized;the maximum transmission rate of PCIe interface was 816MB/s,which was close to the maximum speed of hardware PCIe 2.0 x2,and the whole system achieved reliable transmission at the application layer.The research result can provide an efficient and reliable solution for the application of agricultural monitoring video transmission,and the system had good scalability and generalization.