High-precision time interval measurement method based on phase modulation

Abstract

The invention discloses a high-precision time interval measurement method based on phase modulation. Under the control of digital clock phase-shift, a path of high-frequency and low-jitter clock is transformed to N paths of clock signals having same frequency and fixed phase difference, and is taken as a counter reference clock; a counter is driven to count respectively in N paths of clock periods; two paths of clock signals, which have the smallest error, are extracted by utilizing the clock phase information; through the combination with the clock period and the counted values, the measurement valve of the time interval is worked out. Compared with the method using a single clock for counting, the high-precision time interval measurement method effectively reduces the measurement principle error, and can improve the measurement resolution ratio to 1 / n of the reference clock. A measurement device is connected with a signal conditioning module, an FPGA module, a singlechip module and a display circuit module sequentially according to the signal processing order, and realizes high measurement precision, high measurement resolution ratio, high measurement speed, real time display, and stable and reliable work under a certain crystal oscillation frequency; and the integration in the FPGA is easy, and the expansion is flexible. The high-precision time interval measurement method can be used for measuring the speed in a high-speed motion.

Description

technical field [0001] The invention belongs to the technical field of time interval measurement, and mainly relates to the precise measurement of the intercept time of high-speed moving objects, in particular to a high-precision time interval measurement method based on phase modulation. It is used for speed test in high-speed motion, or provides high-precision time interval measurement for speed test in high-speed motion. Background technique [0002] In the speed test of high-speed moving particles, the time interval is a parameter that needs to be tested frequently. There are many types of chronometers used to measure time intervals. However, in the measurement of the velocity of high-speed moving particles, due to the high speed of high-speed moving particles, the small speed measurement distance, and the complex speed measurement environment, it is easy to be interfered by electromagnetic and power fluctuations, which is different from ordinary environments. Compared ...

AI Technical Summary

Problems solved by technology

The delay line method has a simple structure and is easy to integrate on a single chip. It can realize the measurement of small time intervals. The disadvantage is that with the improvement of measurement resolution, the length of the delay line is required to be shorter and shorter. When the measured time interval value is large, the delay The number of lines will be greatly increased

The basic principle of phase shifting technology is to use n clock signals with the same frequency but with fixed phase difference as the counting clock to drive the counter, and take the average value of the counting as the final measurement result, which can improve the measurement resolution to 1 / n of the reference clock, but This method does not make full use of the phase information of the obtained clock. When the clock frequency is high, the resolution of the phase shift will be reduced, and it is difficult to measure with high precision.

[0008] Through the literature search within a certain range by the applicant of the present invention, no closer relevant information was found

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