基于WiFi的无人机视频传输系统设计与试验

Design and test of unmanned aerial vehicle video transfer system based on WiFi

针对目前传统无人机视频传输系统抗干扰能力差、无法多用户监测的缺点,设计了一种基于Wi Fi的无人机网络实时视频监控系统。系统采用Tiny210嵌入式开发板为核心,通过架设在无人机上的网络监控摄像头和无线网关实现视频采集与传输;嵌入式系统采用Linux操作系统,采用Mjpg-Streamer视频传输方案;S5P210对网络摄像头获得的视频数据依据Mjpg-Streamer方案进行数据格式转换和压缩,通过无线网关上传到网络服务器,监控端计算机组通过监听相应的网络端口实现视频监控。测试结果表明,视频设定分辨率为76 800,当理论帧率在10至25 fps之间递增,视频传输的实际帧率随理论帧率变化接近线性增加,最大实际帧率达到3.27 fps,同时系统占用带宽在每秒1到2 M之间递增,当理论帧率大于25 fps,实际帧率保持最大传输帧率不变,而此过程系统占用带宽在理论帧率25至40 fps之间缓慢递增,大于40 fps后带宽开始下降。设置分辨率大于307 200,摄像头接近其工作极限,视频实际传输帧率维持稳定,与用户设定帧率无关,系统占用带宽平缓保持在每秒2到3 M之间,上位机画面清晰流畅,满足大数据传输下的视频传输要求。该研究为无人机实时性传输、减小运行功耗的深入研究提供了参考。

Aiming at the phenomenon that traditional unmanned aerial vehicle(UAV) video transmission disturbance-resistant ability is limited, not multiple monitors' use. A wireless UAV video transfer system based on Wi Fi network was designed. The system hardware including the framework of the system hardware, embedded development platform Tiny210 which based on the CPU of S5P210 and related peripherals. On the software side, the main note is divided into the Linux embedded operating system programming, and host computer video surveillance software design based on the C#. Using Tiny210 for video data through camera, and then the system gets the data format conversion and compression through the Mjpg-Streamer solution, and computer video monitoring was achieved by listening to the corresponding network port through the wireless network close to the web server. The test results show that the video transfer process, when the resolution is 76 800, the actual frame rate as the theory frame rate increases, after the theory frame rate reach from 10 to 25 fps,the frame rate unchanged and far less than the theoretical. This process increases the system bandwidth, when reached 40 fps peak after falling. When the resolution is greater than 307 200, the actual frame rate does not vary with the theoretical frame rate increases, but remain near constant. Then the camera closes to the operating limit, the system bandwidth keeping from 2 to 3 M every secord, PC screen display is clear and smooth, fully meeting the requirements of video transmission.