Research On The Detection Algorithm Of Dual-mode Vehicle Detector Based On Millimeter Wave Radar And Geomagnetism

With the rapid development of Chinese economy,the increased number of cars has brought great pressure to the construction of parking space.When the speed of parking spaces is approaching saturation,the establishment of a smart parking system and reasonable planning of parking behavior are of great significance to alleviating the problem of parking difficulties.Parking space detection is an important part of the smart parking system,and its accuracy has become an important factor restricting the development of smart parking.In order to improve the accuracy of parking space detection,this article focuses on the following work:1.Aiming at the non-linear problem of VCO frequency modulation,an open-loop correction algorithm based on STM32F746 mic rocontroller is proposed,which effectively realizes the approximation of the ideal frequency modulation curve.This algorithm has the characteristics of low cost and high efficiency.2.In order to improve the signal-to-noise ratio of the radar intermediate frequency signal,the noise reduction algorithm based on CEEMDAN decomposition was used and improved,and the modal boundary point determination algorithm based on the energy mean of the autocorrelation function was proposed,and the sliding window was used.The algorithm performs noise reduction processing on the noise-dominant mode,and the signal-to-noise ratio of the reconstructed signal is increased by 14 d B compared with the original noisy signal.3.Aiming at the problem that the magnetic field sen sor is difficult to deal with the interference of neighboring vehicles and the detection of weak magnetic vehicles,a collaborative decision algorithm based on geomagnetism,radar and adjacent parking space information is proposed.In addition,a set of de tection state machine is designed for the specific realization of the algorithm.An anti-noise peak detection algorithm is designed by analyzing the changing characteristics of the waveform.4.Apply DS evidence theory to parking space detection scenarios,design the initial reliability distribution function,and measure the degree of support of various information to the proposition.In the use of adjacent parking space information,according to the characteristics of similar interference characteristics o f the same source,four characteristics were screened for waveform similarity analysis.5.A set of hardware system is built to test the feasibility of the algorithm,including the detection terminal and the host computer interface.The work flow of the en tire system was formulated,the communication protocol of the upper and lower computers was designed,and the detection effect of the algorithm was evaluated.Based on millimeter-wave radar and geomagnetic sensors,this paper uses DS evidence theory to design a parking space collaborative detection method,and build a hardware system to test the feasibility of the algorithm.The experimental results show that the algorithm can effectively deal with the problems of neighboring car interference and weak magne tic vehicle movement,and improve the accuracy of parking space detection.