High-precision digital phase measurement method based on quadrature phase demodulation technology

Abstract

The present invention discloses a high-precision digital phase measurement method based on a quadrature phase demodulation technology. The method comprises the following steps of: (1) performing datasampling of signals to be measured to obtain digital signals; (2) constructing first reference signals and second signals according to the digital signals, and respectively multiplying by digital signals, performing filtering of the signals after multiplying to allow the signals to only retain difference frequency items, and dividing the two signals after filtering, performing solution of an arc tangent or arc cotangent to obtain phase values of the signals after division; and performing phase unwrapping and removal of linear drift to obtain phase data of the signals to be measured. The wholeflow arrangement, the key steps and the concrete processing process of the measurement method are improved to achieve a high-precision digital measurement method with more convenient parameter regulation and simpler implementation of the phase measurement principle and system and a corresponding system so as to effectively solve the phase measurement precision problem in the scientific research such as precision measurement.

Description

technical field [0001] The invention belongs to the field of precision phase measurement, and more specifically relates to a high-precision digital phase measurement method based on quadrature phase demodulation technology. Background technique [0002] The research on phase measurement technology originated from mathematical vector analysis and circular motion and vibration in physics, and then its application and development in aerospace, resource exploration, etc. made the phase measurement technology develop rapidly. High-precision phase measurement is a key technology in precision measurement scientific research such as atomic clocks, laser interferometers, and laser ranging. The accuracy of phase measurement directly determines the level of scientific research above. Therefore, it is urgent to study high-precision phase measurement system. [0003] There are two methods of phase measurement: analog circuit phase measurement and digital signal processing phase measurem...

AI Technical Summary

Problems solved by technology

This kind of phase meter is still implemented by hardware circuit, and various circuit modules to realize the core algorithm, such as low-pass filter, frequency counter, local oscillator and other electronic devices still affect the phase measurement accuracy, even if the reference signal or reference signal phase or amplitude Any sudden change will cause the phase-locked loop to lose lock, making it impossible to complete accurate phase measurement

[0004] Take other quadrature phase demodulation techniques in the prior art as an example. In these prior art, the generation of the reference signal and the 90-degree phase shift are realized by hardware circuits, which require a reference clock, so the noise of the hardware circuit itself will be Affect measurement accuracy, such as reference signal frequency instability, 90-degree phase shift cannot be very accurate (for example, the actual phase difference may be 89 degrees), affect the accuracy of phase measurement

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