Study On Wire-cable Length Precision Measurement Technology Base On TDPR

It is an important issue to be resolved urgently that the length of wire-cable was precision measured in the process of the cable production, sales and installation. To solve this problem, first introduced and compared the existing methods which were using to measure the length of wire-cable, and focus on the traditional bridge method the time-domain pulse reflection method of them. And then, the paper mainly put emphasis on the research on the time-domain pulse reflection method, discuss the characteristics of wire-related, the pulse reflection principle, a typical waveforms of open-circuit and short-circuit, and effects of the theory of error analysis on the time-domain pulse reflectionThe papers on the one hand, base on the analysis of theory, with MATLAB Simulin -k, made a simulation to verify that the length of cable was measured accurately by the pulse reflection method is feasibility. Simultaneously, using the theory of the relevant -value and correlation coefficient to process the sample data, detecting the maximum value to realize measurement.On the other hand, at the moment of the specific methods achievement, making use of the basis theory of the time interleaved sampling, studying the definition of the data conversion circuit performance parameters, and the applications of algorithm of the AFB method and FFT in the time interleaved sampling. Then, a wire-cable testing precision system was designed, and the function of each module in system was analyzed. One study was focused on the design of ultra-high acquisition module, analysis the functionality and features of the chips in modules and the effects of peripheral circuits on the ultra-high-speed sampling.Finally, based on time-interleaved theory and the time-domain pulse reflection method,building a semi-simulation testbench of the cable length measurement for 4 channels, using the combination of different channels (i.e. 25MHz, 50MHz,100MHz), testing a 100m cable, and displaying the waveform via LabVIEW to verify the sampling error.