A fast frequency measurement method for time-varying frequency sinusoidal signals

Abstract

A fast frequency measurement method for a frequency time-varying sinusoidal signal comprises the steps that the sinusoidal signal is turned into a square wave; T'<xi> serves as the i rising edge moment of an obtained square wave signal, namely, the first rising edge moment is T'<x1>, the N rising edge moment is T'<xN>, and the time length between the first rising edge moment and the Nrising edge moment is T'<x(1,N)>, wherein T'<x(1,N)>=(N-1)T+ / delta T'<x(1,N)>; and standard high-frequency signals f<s> are counted through the to-be-measured square wave signal, and the counting number of f<s> within the T'<x(1,N)> time period is set to be M'<x(1,N)>. According to the fast frequency measurement method, during frequency measurement, a measured value, namely f<x>, of the to-be-measured frequency can be obtained at each rising edge of the to-be-measured frequency. As for a normal frequency measurement method, next frequency measurement is conducted from the (N+1) rising edgemoment to the (N+N) rising edge moment, so that the frequency measurement speed is f<x> / (N-1). The fast frequency measurement method is used for high-precision frequency measurement for the rapidly changed sinusoidal signal, the principle is simple, compared with the traditional frequency measurement method, the change of the external to-be-measured frequency can be reflected, the measurementspeed is high, and the very high practical value is achieved.

Description

technical field [0001] The invention belongs to the field of signal measurement and metering, in particular to a fast frequency measurement method for time-varying frequency sinusoidal signals. Background technique [0002] The frequency measurement of sinusoidal signals is widely used in major scientific experiments, consumer products related to clocks and oscillators, and is an important part of the field of measurement and metrology. For a long time, high-precision real-time Frequency measurement is a difficult problem in the field of frequency measurement. [0003] There are many ways to measure the frequency of a sinusoidal signal. The most conventional method is to use a comparator to change the sinusoidal signal into a square wave signal, and then use methods such as phase comparison method, quantization delay method, multi-cycle synchronous frequency measurement, and quantization delay and multi-cycle synchronous frequency measurement combined method to measure , i...

AI Technical Summary

Problems solved by technology

The most conventional method is to use a comparator to change the sinusoidal signal into a square wave signal, and then use methods such as phase comparison method, quantization delay method, multi-cycle synchronous frequency measurement, and quantization delay and multi-cycle synchronous frequency measurement combined method to measure , its measurement relative accuracy can be better than 1×10 -15 , these measurement methods are all for frequency measurement of time-invariant frequency signals. During the measurement process, the frequency is fixed, so it can be measured for a long enough time. The commonly used measurement time is in the range of 0.1S-1S , for fast-changing frequency signals, on the entire time axis, these measurement methods can only reflect the global average frequency, but cannot reflect the change of local frequency

[0004] For practical engineering applications, such as the rapid frequency measurement of self-excited oscillation optical pump magnetometers used in special fields (such as the field of submarine exploration), it is necessary to perform 1000 frequency measurements within 1 second, that is, to shorten the time of frequency measurement to 1mS, it is difficult to achieve high precision if the frequency measurement is carried out by conventional means

Images