Research On FMCW Vital Signs Detection Radar

Frequency Modulated Continuous Wave(FMCW)radar has been widely used in industrial,transportation and military fields due to its long detection distance,low positioning and speed measurement,low power consumption and small devices.This paper is based on FMCW radar,mainly do the following work.First of all,the algorithm design is based on FMCW radar and uses TI's 77 GHz AWR1443 radar for signal acquisition.This paper introduces the basic structure of FMCW radar,waveform model and range and velocity measurement of FMCW radar.The basic detection principle of FMCW radar used in physical sign detection is introduced in detail.The echo signal collected by analog to digital converter(ADC)is preprocessed.Dynamic target detection algorithm is used on the human body positioning The Moving Target Detention(MTI)method eliminates static clutter and estimates the human position by comparing the maximum values of the slow time dimensions and.Variance was calculated for the slow time dimension to further determine the human position.Next,the human motion signal is extracted.The human motion is mainly obtained by the medium frequency phase change,and the middle frequency signal phase of the frame of the human body is unwound to obtain the human body motion waveform.Secondly,in the separation of signs,this paper focuses on the frequency of signs in complex scenes,and we designed multiple signs separation algorithms.First,the band pass filter + fast Fourier transform is used,and then the Least mean square(LMS)algorithm,variational mode decomposition(VMD)algorithm are used.Based on the VMD algorithm,the VMD algorithm based on whale optimized parameters is applied to the physical sign detection,and the four algorithms are compared.The experiments show that all four algorithms can effectively separate the respiratory signals.In the heartbeat separation,the average difference method is adopted to remove the high harmonic signals through the notch filter and the sliding average filter.Next,the separation of heartbeat signals by four groups of algorithms was compared and analyzed in multiple trials.The improved VMD algorithm with whale optimization parameters had a better separation effect on heartbeat signals.Finally,the physical sign detection radar design was completed.Based on AWR1443 millimeter wave radar chip,the peripheral circuit is designed,and the required parts of the peripheral circuit are selected and schematic.The respiratory and heartbeat signals processed by AWR1443 are decoded by the Coretex R4 M kernel-based chip TM4C1294 NCPDT,and the upper computer display interface is designed by the Matlab APP Designers graphical interface design software.