Design And Implementation Of Precision Time Reference Measurement System Which Be Based On Time Digital Conversion

In daily scientific research and engineering practice, the measurement of a lot of physical quantities needs to be quantified as a time scale. Especially in the field of aerospace measurement and control, the accuracy of time reference and time synchronization affect the accuracy of the measurement and control system for flight control and measurement data directly. Facing the currently low resolution, small measurement range, low precision and design complexity of precision time benchmark measuring instruments, we unite the latest time-to-digital conversion technology, to achieve continuous datum deviation, large range and precision measurement of the system based on the simplified design.First of all, this paper introduces and analyses advantages and disadvantages of several commonly used time-to-digital conversion technology nowadays, then, according to the requirements of specific functionality and performance of the system, we combines the direct pulse counting method and with the tapped delay line method to achieve datum deviation’s accurate measurement, and according to all of the above, the overall scheme of the system has been designed. At the same time, we select the appropriate data processing method to reduce the impact of interference on the results of the data by analyzing the deviation of the system measurement results.Secondly, we make software and hardware design according to the overall system design. Our system uses FPGA chip as the core of its system logic timing control, and then we uses VHDL hardware programming language to achieve reference pulse signal parameter configuration and information extraction, and at the same time, we control two pieces of TDC-GP2 time measurement chip and high-speed pulse counter by using the temporal logic to achieve continuous and accurate measurement of the datum deviation. The system adopts the ARM platform which is based on the wince 6.0 system for parameter setting and data processing terminal, and uses C# programming language to write send-receive procedures, data processing program and graphical display program, in this case we realize the display and storage of measurement results for system reference pulse information and local datum deviation.Finally, we test the function and performance of application environment simulated by our design, the experimental results show that the system can realize the effective continuous measurement time of datum deviation and effectiveness of data processing methods, which also verify that the system can achieve the measurement range 1ns~1.2s, highest resolution 100 ps, and the measuring accuracy can reach the set value 0.0015% + 0.3ns. Meanwhile the system can simplify the design in the permit of ensuring the premise of system function and performance.