Embedded Data Recorder Based On DM355

During the process of the tests, we need to collect all kinds of flight data in order to improve the capabilities of the missiles by analyzing the data after the test. In order to record the device’s conditions on small aircraft and its outside scene in real-time, this paper designs a data recorder used in the missiles. The device could receive video data including the information of the experimental scene which collected from the camera in the missiles. At the same time, it can also record the flight parameters of the missile. We could analyze the results of the test according to the data collected by the device.The embedded data-recording platform is established which based on analysis for the system’s working condition, performance requirement and video-encoding methods.The platform is built on the ARM chip DM355 with video compression coprocessor,achieving many interfaces such as CAN bus, serial external memory and video encoding,we will transplant the Linux system on the platform after passing the tests. At the same time, we could develop application program and the drivers for the external equipment.Application software is proposed through building communication protocol on CAN bus, which can receive and parse the control commands and flight status data messages sent by other masters, using hard-core to realize the real-time video compression and storing the critical data in an external SD card. Video will be captured as MJPEG compression instead of MPEG4 files to avoid losing data due to power outages. When designing the software platform of the embedded data recorder, we use the ping-pong buffer and multithreading to improve the rate of the video encoding.When achieve the functions for the soft platform, we need to debug and improve the whole platform. Run the drivers and application software as well as the initialization operation when the embedded data recorder starts. In order to simplify the debugging work for the software platform, designing a kind of software running on PC. The software could simulate the computer on the missile sending command to control the device.After field test result shows: The embeded data recorder can record the data sent by the main control, video capture and compression rates up to 25 frames / sec(720 * 576), and can avoid losing data when power is lost. In the fourth chapter shows the simulation test’s results because of the security of the data from the field test.