Prestanda och precision pa? en enkortsdator i ett system med realtidskrav
KamerasystemEnkortsdatorRaspberry PiVideosignalCPU-anva?ndningServerkommunikationNa?tverkstrafikSaab AB
The report aims to investigate how well a certain type of affordable embedded single board computer can hold up against today's more expensive computers in a computer system by doing various tests on a system with the specified requirements. The system has a Raspberry Pi as the single board computer which task is to control a camera based on coordinates obtained from a server as well as capture and stream a video signal on a network.The researches were conducted to check how much network traffic a single-chip computer sent in different video formats and how much CPU utilization was required. Studies were also made to ensure the accuracy of the camera control. The researches have been experimental, where several tests have been performed and analyzed.The results show that a sufficiently good accuracy can be obtained from the camera steering unit, in which two different servos have been investigated. When the video format MJPEG and H.264 are used, the single-chip computer is able to transmit a video signal up to 1280x720 at 15 fps. The system managed to download and perform calculations on an object from the server at 42.3 ms.When the entire system was up and running at the same time the Raspberry Pi didn?t manage to deliver a video signal and obtain the coordinates from the server fast enough. Depending on the video format the performance on the single-chip computer varied, but no setup managed to keep the system stable enough to reach the requirements.