Research On The Data Recorder And The Test System

The data recorder is mainly used for recording the working state parameters of the aircraft in flight test.After the equipment landed,we uploaded the data that we collected to the computer for analysis of data and improve the design of the aircraft.Due to the huge cost of conducting a flight test,the strict and comprehensive performance testing for it should be needed to ensure the success of the test before use.Based on the test of the performance of the missile-borne equipment,the ground signal test bench is designed.Because the two are related to the interface,the data recorder and the test bench should be developed together,which constitute the whole test system.Because the data recorder needs to record information accurately in high temperature and high pressure working condition,a dual backup memory circuit using NAND flash as storage medium is designed,and cache design,error correction design,balanced loss design and bad block management are used to achieve the control optimization design of NAND flash storage.In order to verify the functionality of the data acquisition module,the test station simulates the external signals and sends analog signals and PCM data streams to the data logger.After the analog signal is converted by AD,the recorder mixes the PCM data with a certain format,and is stored in two NAND flash.In the process of data record,there will be a RS-422 signal that gives feedback of internal working state of the data recorder,which facilitates our understanding of its status.The download mode of the recorder consists of one RS-422 instruction interface and one LVDS download Interface.After the test station sends the download command,the busy state is sent to the recorder according to the half full mark of the internal cache,and the recorder controls the sending of the data according to the received information.Download data uses8B/10 B encoding,and uses driver chip to achieve long-term data transmission.As in the previous design,the speed of data download is slower and more fixed,using this design with adaptive download control increases the speed at which the data is received by the tester,saving time for unit testing.In this dissertation,the key technologies of the two working modes of data logger are studied.A large number of tests are carried out on the acquisition and storage mode and thedownload mode.The test results show that there are no errors and losses in the process of unit testing.The data logger is stable and reliable,and the design is feasible.