Study On Key Technology Of 24GHz Radar Ranging System

Recently,with the development of the un-touching measurement technology and intelligent monitoring,many aspects have appeared distance measurement requirements,such as automotive anti-collision,monitoring the surface of water,electronic speed,security monitoring and so on.At this point,research on the key technology in distance measurement is significant.The common method of distance measurement includes infrared ranging,laser ranging,ultrasonic ranging,video ranging and microwave ranging.Combined with the application of microwave sensors in the ranging monitoring and the research need of the subject,this paper proposed the 24? GHz microwave radar ranging system and study its frequency modulation technology and siginal processing method.The results and study content of this article displayed below:1.Combined with the research need of the subject,selected 24? GHz radar ranging technologySeveral kinds of common ranging technology are introduced,they included laser ranging technology,ultrasonic ranging technology,infrared ranging technology,video ranging technology and microwave ranging technology.According to multifactorial analysis advantage and disadvantage of several ranging technology and external environment of the ranging system,this paper adapted to 24? GHz ranging system to experimentally study.2.To improve the system real-time,mixed wave of swatooth wave and triangular wave frequency modulation was adoptedAccording to the shortcomings of changing cycle triangular wave frequency modulation,this paper improved it and adopted mixed wave of swatooth wave and triangular wave frequency modulation method.MATLAB simulation of mixed wave of swatooth wave and triangular wave frequency modulation method and changing cycle triangular wave frequency modulation,comparison of simulation results illustrated the measurement error of distance is same and velocity is within 0.8? m/s,but siginal processing time is reduced by more than 2 times,improving the real-time feature of system.3.To improve system performance,FFT-Chirp Z transform and wavelet threshold denoising were used and analyzedSignal processing is the key produce of radar ranging system,so this paper adapted to FFT-Chirp Z transform method to process intermediate frequency signal.In the absence of noise,compared with the FFT transform method,under the premise of ensure the accuracy of distance and velocity,the signal processing of FFT-Chirp Z method reduced by 7 to 8 times,but in the case of noise,the impact of noise is relatively large,accuracy of diatance and velocity have declined and analyzed its reason.Because of the impact of noise,this paper used wavelet threshold denoising to process frequency signal.According to FFT-Chirp Z method to obtain distance and velocity error curvilinear,and compared with the error obtained by simulation of no denosing,the distance error is reduced by 3 times and the speed error is reduced by 2times.4.24? GHz radar ranging system design and test experiments,ellipticalhyperbolic positioning method was certifiedIn the hardware,24? GHz radar ranging system had been designed and used it to do radar ranging experiment.Single-node ranging experiment had been done,measurement range is 0~80? m,measurement error is less than 4% and range error is within 0.8? m.In order to detect the exact location of the object,the elliptical-hyperbolic positioning method was adopted to calculate the coordinate information and angle information.This paper used double node ranging experiment,the experiment results showed that coordinate information error is within 1.2? m and angle error is less than 0.5°.The feasibility of the elliptical-hyperbolic positioning method was verified.