Phase difference detection method and system, double-crystal oscillation mixer circuit and distance measurement apparatus

Abstract

The invention belongs to the field of phase difference detection and provides a phase difference detection method, a phase difference detection system, a dual crystal resonator mixer circuit and a distance measurement device. The phase difference detection method comprises the following steps: generating two high frequency oscillation signals of different frequencies, and dividing each high frequency oscillation signal into two paths, wherein one path is a local reference signal used for local reference and the other path is a distance measurement signal for distance measurement; mixing the two paths of local reference signals and outputting a low frequency first difference frequency signal; mixing a return signal of light waves which are modulated according to one path of distance measurement signal and transmitted to the position of a measured target to be reflected and the other path of distance measurement signal, and outputting a second difference frequency signal; and subtracting the first difference frequency signal from the second difference frequency signal to obtain the phase difference between the second difference frequency signal and the first difference frequency signal. The phase difference detection system has the advantages of high precision, low cost, good stability, low energy consumption, and the like, and is used for high-precision phase difference detection, and can achieve millimetre-sized measurement precision.

Description

technical field [0001] The invention belongs to the field of phase difference detection, and in particular relates to a phase difference detection method, a phase difference detection system, a double crystal oscillator frequency mixing circuit, and a distance measuring device. Background technique [0002] With the rapid development of semiconductor lasers and digital circuits since the 1980s, long-distance and high-precision laser ranging technology has become more and more widely used in electric power, water conservancy, communications, environment, construction, police, fire protection, blasting, and navigation. , railways, military anti-terrorism and other fields. Phase-type laser ranging products with millimeter-level measurement accuracy have gradually become dominant in short-range laser ranging within 200 meters. [0003] The phase-type laser distance measuring device based on the principle of phase difference measurement uses a continuously modulated laser beam t...

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Problems solved by technology

[0004] The purpose of the embodiment of the present invention is to provide a phase difference detection method, aiming to solve the problems of low precision, high cost and high power consumption of the phase laser distance measuring device using the PLL circuit in the prior art

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