The Design And Implementation Of Digital Converter Test Bench Of A Launch Vehicle Telemetry System

Digital converter, which provides all the required parameters during the flight of the vehicle for the ground in the process of vehicle emission, is the core component of vehicle telemetry system. Therefore, the precision, stability and reliability of the telemetry system digital converter are of particular importance. The test bench of digital converter, which is used to simulate all the status signals (frame synchronization, code synchronization, the computer word, bit signal, take-off signal, etc.) at the time of vehicle'take-off to detect whether the system digital converter works, is a specialized test equipment in the ground designed for the telemetry system digital converter. The test bench is the equipment which sets the generation, transmission and transportation of signals, the collection and compilation frame of information data and the pulse, the automatic detection, automatic measurement and data analysis of the performance in one.The test bench of digital converter in the past was huge in size, the hardware circuit complex in design, and the integration of circuits relatively low. Because the communication interface had also changed as the development of PC, there was no real-time monitoring capabilities function in the software design. After analyzing the function indexes the task books bring forth, the analysis puts forward a new design of digital converter, which adopts FPGA as the central logic controller, USB as the data transfer, bus mode and modular mode as the design method in system, with commonality and expansibility. According to the functions of each module, respectively considering the hardware circuitry, the logic timing, and the software design of host computer, it can reliably complete downloading all the data of signal sources and display functions of all the measured signals in real-time collection, analysis and processing. It not only saves development cost of system and shortens the development cycle of equipment, but also improves the reliability, maintainability, reconfigurability, and environmental adaptability of system. You can always judge the work state of telemetry systems and diagnosis the error in time.