Frequency domain vehicle detecting method based on single-frequency continuous wave radar

Abstract

The invention relates to a frequency domain vehicle detecting method based on a single-frequency continuous wave radar, which belongs to the technical field of intelligent traffic vehicle detection. The method comprises the following steps of: installing a radar on a road in the forward direction; establishing an x-h coordinate system; carrying out time frequency analysis on a single-frequency continuous wave time domain radar signal to obtain an image of the Doppler frequency of an echo signal, wherein the Doppler frequency is changed along with time, fd is the Doppler frequency of a reflection echo of a vehicle scattering center, and v is vehicle relative speed; starting detection from an S0 state, firstly, detecting a starting point Ps; detecting a middle point Pm; finally detecting a terminal point Pe and returning a detecting state from S2 to S0; and after entering each state Si, accumulating retaining time in Si by the detecting method to obtain vehicle detecting information. The invention can effectively reduce noise interference and the influence of a vehicle at a lateral driveway on a detecting result, decrease target splitting caused by intensity fluctuation of the echo signal, improve the estimating precision of vehicle entrance time and ensure that the overall performance of the other following methods is enhanced.

Description

technical field A frequency-domain vehicle detection method based on a single-frequency continuous wave radar relates to vehicle detection such as detection and speed measurement of vehicles on the road by using a single-frequency continuous wave radar, and belongs to the technical field of intelligent transportation vehicle detection. Background technique The single-frequency continuous wave radar adopts the working method of continuously transmitting microwave signals, and uses a zero-IF receiver to directly mix the local oscillator signal and the received signal to obtain the Doppler signal. Single-frequency continuous wave radar has the advantages of simple structure, reliability and low cost, and has been applied to the detection and speed measurement of vehicle targets. For single frequency continuous wave radar, target detection can be done from time domain or frequency domain. Time-domain detection uses the amplitude information of the echo to set the threshold for...

AI Technical Summary

Problems solved by technology

The present invention aims at the problems that the current vehicle detection radar conducts from the time domain of the Doppler signal, which requires high signal-to-noise ratio, poor detection performance, and weak suppression ability to noise, and proposes the use of low-cost single-frequency continuous wave Method of detecting vehicle Doppler information provided by radar in frequency domain

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