scholarly journals Single-Channel FMCW-Radar-Based Multi-Passenger Occupancy Detection Inside Vehicle

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1472
Author(s):  
Heemang Song ◽  
Hyun-Chool Shin
Keyword(s):  
Continuous Wave ◽  
Single Channel ◽  
Spectral Power ◽  
Likelihood Estimation ◽  
Radar Signal ◽  
Linear Discriminant ◽  
Fmcw Radar ◽  
Time Frequency ◽  
Occupancy Detection ◽  
Wave Radar

In this paper, we provide the results of multi-passenger occupancy detection inside a vehicle obtained using a single-channel frequency-modulated continuous-wave radar. The physiological characteristics of the radar signal are analyzed in a time-frequency spectrum, and features are proposed based on these characteristics for multi-passenger occupancy detection. After clutter removal is applied, the spectral power and Wiener entropy are proposed as features to quantify physiological movements arising from breathing and heartbeat. Using the average means of both the power and Wiener entropy at seats 1 and 2, the feature distributions are expressed, and classification is performed. The multi-passenger occupancy detection performance is evaluated using linear discriminant analysis and maximum likelihood estimation. The results indicate that the proposed power and Wiener entropy are effective features for multi-passenger occupancy detection.

scholarly journals Automotive Frequency Modulated Continuous Wave Radar Interference Reduction Using Per-Vehicle Chirp Sequences

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2831 ◽  
Author(s):  
Youn-Sik Son ◽  
Hyuk-Kee Sung ◽  
Seo Heo
Keyword(s):  
Continuous Wave ◽  
Signal Interference ◽  
Radar Signal ◽  
Driver Assistance ◽  
Interference Reduction ◽  
Fmcw Radar ◽  
Radar Sensors ◽  
Vehicle To Vehicle ◽  
Radar Systems ◽  
Wave Radar

Recently, many automobiles adopt radar sensors to support advanced driver assistance system (ADAS) functions. As the number of vehicles with radar systems increases the probability of radar signal interference and the accompanying ghost target problems become serious. In this paper, we propose a novel algorithm where we deploy per-vehicle chirp sequence in a frequency modulated continuous wave (FMCW) radar to mitigate the vehicle-to-vehicle radar interference. We devise a chirp sequence set so that the slope of each vehicle’s chirp sequence does not overlap within the set. By assigning one of the chirp sequences to each vehicle, we mitigate the interference from the radar signals transmitted by the neighboring vehicles. We confirm the performance of the proposed method stochastically by computer simulation. The simulation results show that the detection and false alarm performance is improved significantly by the proposed method.

scholarly journals Characterisation of human gait using a continuous-wave radar at 24 GHz

2008 ◽  
Vol 6 ◽  
pp. 67-70 ◽  
Author(s):  
C. Hornsteiner ◽  
J. Detlefsen
Keyword(s):  
Moving Objects ◽  
Continuous Wave ◽  
The Body ◽  
Human Gait ◽  
Radar Signal ◽  
Body Parts ◽  
Mean Velocity ◽  
Time Frequency ◽  
Wave Radar ◽  
Wide Range

Abstract. Human locomotion consists of a complex movement of various parts of the body. The reflections generated by body parts with different relative velocities result in different Doppler shifts which can be detected as a superposition with a Continuous-Wave (CW) Radar. A time-frequency transform like the short-time Fourier transform (STFT) of the radar signal allows a representation of the signal in both time- and frequency domain (spectrogram). It can be shown that even during one gait cycle the velocity of the torso, which constitutes the major part of the reflection, is not constant. Further a smaller portion of the signal is reflected from the legs. The velocity of the legs varies in a wide range from zero (foot is on the ground) to a velocity which is higher than that of the torso. The two dominant parameters which characterise the human gait are the step rate and the mean velocity. Both parameters can be deduced from suitable portions of the spectrogram. The statistical evaluation of the two parameters has the potential to be included for discrimination purposes either between different persons or between humans and other moving objects.

scholarly journals Research of Target Detection and Classification Techniques Using Millimeter-Wave Radar and Vision Sensors

2021 ◽  
Vol 13 (6) ◽  
pp. 1064
Author(s):  
Zhangjing Wang ◽  
Xianhan Miao ◽  
Zhen Huang ◽  
Haoran Luo
Keyword(s):  
Millimeter Wave ◽  
Autonomous Vehicles ◽  
Texture Features ◽  
Heterogeneous Data ◽  
Environmental Perception ◽  
Radar Signal ◽  
Time Frequency ◽  
Fusion Data ◽  
Wave Radar ◽  
Automation Equipment

The development of autonomous vehicles and unmanned aerial vehicles has led to a current research focus on improving the environmental perception of automation equipment. The unmanned platform detects its surroundings and then makes a decision based on environmental information. The major challenge of environmental perception is to detect and classify objects precisely; thus, it is necessary to perform fusion of different heterogeneous data to achieve complementary advantages. In this paper, a robust object detection and classification algorithm based on millimeter-wave (MMW) radar and camera fusion is proposed. The corresponding regions of interest (ROIs) are accurately calculated from the approximate position of the target detected by radar and cameras. A joint classification network is used to extract micro-Doppler features from the time-frequency spectrum and texture features from images in the ROIs. A fusion dataset between radar and camera is established using a fusion data acquisition platform and includes intersections, highways, roads, and playgrounds in schools during the day and at night. The traditional radar signal algorithm, the Faster R-CNN model and our proposed fusion network model, called RCF-Faster R-CNN, are evaluated in this dataset. The experimental results indicate that the mAP(mean Average Precision) of our network is up to 89.42% more accurate than the traditional radar signal algorithm and up to 32.76% higher than Faster R-CNN, especially in the environment of low light and strong electromagnetic clutter.

scholarly journals FPGA Implementation of an Efficient FFT Processor for FMCW Radar Signal Processing

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6443
Author(s):  
Jinmoo Heo ◽  
Yongchul Jung ◽  
Seongjoo Lee ◽  
Yunho Jung
Keyword(s):  
Signal Processing ◽  
Detection Rate ◽  
Continuous Wave ◽  
Vital Signs ◽  
Radar Signal ◽  
Radar Signal Processing ◽  
Fmcw Radar ◽  
Design And Implementation ◽  
Fft Processor ◽  
Point Operator

This paper presents the design and implementation results of an efficient fast Fourier transform (FFT) processor for frequency-modulated continuous wave (FMCW) radar signal processing. The proposed FFT processor is designed with a memory-based FFT architecture and supports variable lengths from 64 to 4096. Moreover, it is designed with a floating-point operator to prevent the performance degradation of fixed-point operators. FMCW radar signal processing requires windowing operations to increase the target detection rate by reducing clutter side lobes, magnitude calculation operations based on the FFT results to detect the target, and accumulation operations to improve the detection performance of the target. In addition, in some applications such as the measurement of vital signs, the phase of the FFT result has to be calculated. In general, only the FFT is implemented in the hardware, and the other FMCW radar signal processing is performed in the software. The proposed FFT processor implements not only the FFT, but also windowing, accumulation, and magnitude/phase calculations in the hardware. Therefore, compared with a processor implementing only the FFT, the proposed FFT processor uses 1.69 times the hardware resources but achieves an execution time 7.32 times shorter.

scholarly journals Asynchronous electric field visualization using an integrated multichannel electro-optic probe

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shintaro Hisatake ◽  
Junpei Kamada ◽  
Yuya Asano ◽  
Hirohisa Uchida ◽  
Makoto Tojo ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Near Field ◽  
Horn Antenna ◽  
Optimal Placement ◽  
Radar Signal ◽  
Radiation Patterns ◽  
Practical Applications ◽  
Fmcw Radar ◽  
Realistic Situation ◽  
Reference Probe

Abstract The higher the frequency, the more complex the scattering, diffraction, multiple reflection, and interference that occur in practical applications such as radar-installed vehicles and transmitter-installed mobile modules, etc. Near-field measurement in “real situations” is important for not only investigating the origin of unpredictable field distortions but also maximizing the system performance by optimal placement of antennas, modules, etc. Here, as an alternative to the previous vector-network-analyzer-based measurement, we propose a new asynchronous approach that visualizes the amplitude and phase distributions of electric near-fields three-dimensionally without placing a reference probe at a fixed point or plugging a cable to the RF source to be measured. We demonstrate the visualization of a frequency-modulated continuous wave (FMCW) signal (24 GHz ± 40 MHz, modulation cycle: 2.5 ms), and show that the measured radiation patterns of a standard horn antenna agree well with the simulation results. We also demonstrate a proof-of-concept experiment that imitates a realistic situation of a bumper installed vehicle to show how the bumper alters the radiation patterns of the FMCW radar signal. The technique is based on photonics and enables measuring in the microwave to millimeter-wave range.

Semi-Physical Simulation System for FMCW Radar

2011 ◽  
Vol 135-136 ◽  
pp. 886-892
Author(s):  
Wen Hui Chen ◽  
Xin Xi Meng ◽  
Xiao Min Liu
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Physical Simulation ◽  
Continuous Wave ◽  
Low Cost ◽  
Simulation System ◽  
Radar Signal ◽  
Low Power Consumption ◽  
Fmcw Radar ◽  
Data Process

In order to process and analyze the signal of frequency modulated continuous wave (FMCW) radar, a radar semi-physical simulation(RSPS) system based on STM32F103VE6 chip is designed in this paper. By designing the hardware and software of system, the RSPS system can process the radar signal, detect the target, verify the data process algorithm and display the result on TFT-LCD screen. In addition, the collected data can be uploaded to PC by RS-232 interfaces which improves the reliability, stability and practicability of system. The waveform and spectrum maps are utilized to show the feasibility of RSPS system in analysing FMCW radar signal. Experimental results show that this system has many advantages, such as multifunction, low power consumption and low cost.

Target Range and Velocity Measurement to Reduce False Targets in FMCW Automotive Anti-Collision Radar

2012 ◽  
Vol 253-255 ◽  
pp. 1410-1417 ◽  
Author(s):  
Zhi Gang Li ◽  
Qiong Chan Gu
Keyword(s):  
Computer Simulation ◽  
Theoretical Analysis ◽  
Continuous Wave ◽  
Target Range ◽  
Multiple Targets ◽  
Fmcw Radar ◽  
Wave Radar ◽  
Frequency Modulate ◽  
Inherent Problem ◽  
Simulation Results

For frequency modulate continuous wave radar, it is necessary and difficult to search the pairs of beat frequencies in an up-chirp mode and a down-chirp mode t o measure range and velocity of multiple targets. However, the inherent problem of FMCW radar is multiple targets detection. False targets can appearance because of mistaking the combination of these beat frequencies. A novel waveform named double-slope symmetrical saw-tooth wave is proposed and its corresponding algorithm is also introduced to resolve the problem of multiple targets detection for automotive anti-collision radar. Computer simulation results and theoretical analysis prove that the method is effective and practical for multiple targets detection in intelligence transportation system.

scholarly journals Planar millimeter wave radar frontend for automotive applications

2003 ◽  
Vol 1 ◽  
pp. 125-129 ◽  
Author(s):  
J. Grubert ◽  
J. Heyen ◽  
C. Metz ◽  
L. C. Stange ◽  
A. F. Jacob
Keyword(s):  
Continuous Wave ◽  
Phase Lock Loop ◽  
Automotive Applications ◽  
Cruise Control ◽  
Fully Integrated ◽  
Fmcw Radar ◽  
Wave Radar ◽  
Feed Network ◽  
Zukünftige Entwicklungen ◽  
77 Ghz

Abstract. A fully integrated planar sensor for 77 GHz automotive applications is presented. The frontend consists of a transceiver multichip module and an electronically steerable microstrip patch array. The antenna feed network is based on a modified Rotman-lens and connected to the array in a multilayer approach offering higher integration. Furthermore, the frontend comprises a phase lock loop to allow proper frequency-modulated continuous wave (FMCW) radar operation. The latest experimental results verify the functionality of this advanced frontend design featuring automatic cruise control, precrash sensing and cut-in detection. These promising radar measurements give reason to a detailed theoretical investigation of system performance. Employing commercially available MMIC various circuit topologies are compared based on signal-tonoise considerations. Different scenarios for both sequential and parallel lobing hint to more advanced sensor designs and better performance. These improvements strongly depend on the availability of suitable MMIC and reliable packaging technologies. Within our present approach possible future MMIC developments are already considered and, thus, can be easily adapted by the flexible frontend design. Es wird ein integrierter planarer Sensor für 77 GHz Radaranwendungen vorgestellt. Das Frontend besteht aus einem Sende- und Empfangs-Multi-Chip-Modul und einer elektronisch schwenkbaren Antenne. Das Speisenetzwerk der Antenne basiert auf einer modifizierten Rotman- Linse. Für eine kompakte Bauweise sind Antenne und Speisenetzwerk mehrlagig integriert. Weiterhin umfasst das Frontend eine Phasenregelschleife für eine präzise Steuerung des frequenzmodulierten Dauerstrichradars. Die aktuellen Messergebnisse bestätigen die Funktionalit¨at dieses neuartigen Frontend-Designs, das automatische Geschwindigkeitsregelung, Kollisionswarnung sowie Nahbereichsüberwachung ermöglicht. Die Qualität der Messergebnisse hat weiterführende theoretische Untersuchungen über die potenzielle Systemleistungsfähigkeit motiviert. Unter Berücksichtigung von kommerziell erhältlichenMMICs werden verschiedene Schaltungstopologien auf der Grundlage des Signal-Rausch-Verhältnisses verglichen. Sowohl für sequenzielle als auch für parallele Ansteuerung der Antennenkeulen wird eine deutliche Leistungssteigerung ermittelt. Diese Verbesserungen hängen maßgeblich von der Verfügbarkeit geeigneter MMICs und einer zuverlässigen Aufbau- und Verbindungstechnik ab. Das vorliegende Frontend-Konzept kann auf Grund seiner Flexibilität leicht an derlei zukünftige Entwicklungen angepasst werden.

scholarly journals Deep Learning-Based Indoor Two-Dimensional Localization Scheme Using a Frequency-Modulated Continuous Wave Radar

Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2166
Author(s):  
Kyungeun Park ◽  
Jeongpyo Lee ◽  
Youngok Kim
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Deep Neural Network ◽  
Continuous Wave ◽  
Two Dimensional ◽  
Fmcw Radar ◽  
Localization Scheme ◽  
Wave Radar ◽  
Conventional Scheme ◽  
24 Ghz

In this paper, we propose a deep learning-based indoor two-dimensional (2D) localization scheme using a 24 GHz frequency-modulated continuous wave (FMCW) radar. In the proposed scheme, deep neural network and convolutional neural network (CNN) models that use different numbers of FMCW radars were employed to overcome the limitations of the conventional 2D localization scheme that is based on multilateration methods. The performance of the proposed scheme was evaluated experimentally and compared with the conventional scheme under the same conditions. According to the results, the 2D location of the target could be estimated with a proposed single radar scheme, whereas two FMCW radars were required by the conventional scheme. Furthermore, the proposed CNN scheme with two FMCW radars produced an average localization error of 0.23 m, while the error of the conventional scheme with two FMCW radars was 0.53 m.

scholarly journals Vital Sign Monitoring Using FMCW Radar in Various Sleeping Scenarios

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6505
Author(s):  
Emmi Turppa ◽  
Juha M. Kortelainen ◽  
Oleg Antropov ◽  
Tero Kiuru
Keyword(s):  
Heart Rate ◽  
Remote Monitoring ◽  
Vital Sign ◽  
Continuous Wave ◽  
Real Life ◽  
Vital Signs ◽  
Absolute Error ◽  
Physical Contact ◽  
Radar Signal ◽  
Fmcw Radar

Remote monitoring of vital signs for studying sleep is a user-friendly alternative to monitoring with sensors attached to the skin. For instance, remote monitoring can allow unconstrained movement during sleep, whereas detectors requiring a physical contact may detach and interrupt the measurement and affect sleep itself. This study evaluates the performance of a cost-effective frequency modulated continuous wave (FMCW) radar in remote monitoring of heart rate and respiration in scenarios resembling a set of normal and abnormal physiological conditions during sleep. We evaluate the vital signs of ten subjects in different lying positions during various tasks. Specifically, we aim for a broad range of both heart and respiration rates to replicate various real-life scenarios and to test the robustness of the selected vital sign extraction methods consisting of fast Fourier transform based cepstral and autocorrelation analyses. As compared to the reference signals obtained using Embla titanium, a certified medical device, we achieved an overall relative mean absolute error of 3.6% (86% correlation) and 9.1% (91% correlation) for the heart rate and respiration rate, respectively. Our results promote radar-based clinical monitoring by showing that the proposed radar technology and signal processing methods accurately capture even such alarming vital signs as minimal respiration. Furthermore, we show that common parameters for heart rate variability can also be accurately extracted from the radar signal, enabling further sleep analyses.

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