Performance Optimization Design Of Telemetry Acquisition And Coding Device

The telemetry acquisition and coding device is used to acquisite and code telemetry signal. In order to further improve the acquisition accuracy of acquisition and coding device, reduce or avoid signal aliasing and oscillation during the acquisition process, the design method of analog acquisition circuit has been lucubrated by this paper, the system hardware and logical design had been optimized, thereby the acquisition precision of the system telemetry acquisition and coding device. Only the design is comprehensive and reasonable, can ensure that more authentic and more accurate signal is collected.Taken telemetry acquisition and coding device as the research entity, this paper has researched the development status of the data acquisition system at home and abroad, some related data acquisition methods which can improve the acquisition precision. Besides that optimized the hardware circuit and control logic of telemetry acquisition and coding device.Firstly, the paper analyzed the original design of telemetry acquisition and coding device, expounded the principle and function of the telemetry acquisition and coding device, described in detail the design principles of each module of the device and the influence of system. FPGA is the control device to the telemetry acquisition and coding device. It controlled the two-stage analog switches to switch, sent all of the input analog signals to ADC orderly for A/D conversion. The signal occurred self-excited oscillation after through the operational amplifier in the signal input port, and the ADC input signal had much bigger ripple. In view of the two above problems which affected the acquisition precision, the paper established the increasing noise gain of operational amplifier circuit model, anti-aliasing RC filter model, and moving average filter model. Based on these models, the paper optimized the hardware circuit and control logic of telemetry acquisition and coding device, thereby improved its performance. Finally, it tested the performance of the optimized circuit, including signal conditioning circuit test, moving average filter simulation, and so on. The result showed, the acquisition precision of the optimized circuit has been improved greatly.