| With the progress of modern science and production technology,modern engineering construction puts forward higher requirements for the precision,real-time and dynamic of engineering measurement.The traditional measurement technologies and equipments are more and more difficult to meet the needs of modern engineering construction,so the new technology and equipment should be introduced to the area to improve the quality and efficiency of work.As a new non-contact high-precision sensor,millimeter wave radar(MMW Radar)has significant advantages in the precise measurement of target.Its application in the field of engineering measurement has a positive significance for the development of the whole mapping and surveying field.In view of this,this paper takes millimeter wave radar as the research object,focusing on the radrar signal processing flow,algorithm and application in the field of precision measurement,which provides some support for the development of modern engineering measurement.The main research work of this paper includes:(1)The classification,system structure,working principle and process of millimeter wave radar are introduced in detail.The radar equation that affects the radar observation performance is derived,and then the paper takes the sawtooth FMCW(frequency modulated continuous Wave)millimeter wave radar as research object and discusses the basic principle of ranging and velocity measurement in detail.The research results show that the observation information of millimeter wave radar is included in the frequency and phase information of signal.Finally,the paper analyzes range resolution and velocity resolution of millimeter wave radar and simulates the algorithm of radar ranging and velocity measurement.The target observation is successfully extracted from radar signal.(2)The precise ranging algorithm of FMCW MMW radar is derived and simulated.It is pointed out that the main error source of radar ranging is the fence effect in frequency detection.Based on this,a three-stage frequency measurement algorithm using FFT(fast Fourier transform)+ Chirp-Z transform + spectral line correction is proposed to improve the measurement accuracy.A comparative simulation experiment is carried out based on this algorithm.The experimental results show that compared with the traditional FFT spectrum analysis method,the algorithm can significantly improve the accuracy of spectrum estimation,and then improve the accuracy of radar ranging,which is suitable for millimeter wave radar measurement applications.(3)The technology of radar multidimensional space measurement is studied.This paper analyzes the basic principle of radar angle measurement,deduces the calculation formula of radar angle resolution,and introduces multiple input and multiple output(MIMO)technology to solve the contradiction between resolution and radar hardware.The paper analyzes the antenna layout of MIMO radar used in threedimensional measurement and deduces the three-dimensional coordinate calculation formula of space target and finally proposes a new coordinate conversion algorithm.(4)The paper introduces the millimeter wave radar measurement platform we built based on AWR1443 BOOST.The paper describes the selection of millimeter wave radar and hardware parameters in detail,and completes the hardware development based on the radar development software provided by the radar official,and develops the corresponding software platform for data transmission and processing according to the actual needs.Finally,the system is used to carry out indoor and outdoor experiments.The experimental results show that the radar platform is in good condition and has high accuracy.(5)The application of millimeter wave radar in practical precise engineering measurement is studied.The vibration detection experiment of the high-speed railway bridge along the Beijing Shanghai high-speed railway was carried out with the millimeter wave radar measurement platform.With modern time-frequency analysis methods,the radar data are processed from time domain and frequency domain.The bridge vibration eigenvalues are extracted accurately and the health status of the bridge is evaluated.Experiments show that millimeter wave radar can be used in highprecision engineering measurement industry as a new technology.There are 68 figures,18 tables,110 references in this theiss. |
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