Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
19 results
Search Results
Item Experimental Study of 24GHz Sense2Gol Pulse Radar Sensor for Human Vital Sign Measurement(Institute of Electrical and Electronics Engineers Inc., 2021) Srihari, P.; Vandana, G.S.Noncontact sensor based vital sign measurement has gained predominant attention in recent years. Frequency Modulated Continuous Wave (FMCW) radar-based sensors are deployed for this purpose at millimetre (mm) wavelengths (typically, 60 GHz and 77 GHz) to obtain vital sign measurements for various applications. This paper proposes a 24GHz Sense2Gol radar sensor-based heart rate (HR) and breath rate (BR) measurement system. Real data is collected using experimental setup from 12 male subjects and 12 female subjects of various age groups (with average age of male subjects is 40.5 years and average age of female subjects is 37.4 years). The data from the I/Q channel of the Sense2Gol radar sensor is passed through a band-pass filter followed by evaluating fast Fourier transform (FFT) to determine the HR beat per minute (bpm). To estimate the BR the arc tangent demodulation, phase unwrapping, followed by band-pass filtering is performed. The FFT is carried out for the resultant signal. The practical results from this experiment reveals that the male subjects and female subjects have an average value (HR: 63.92 bpm for male,64.97 bpm for female; BR:17.38 bpm for male, 17.45 bpm for female) of HR and BR respectively for male and female candidates. Further, over all HR across all subjects (both male and female) is 64.44 and BR across all subjects is 17.41. This Sense2Gol pulse radar sensor is relatively inexpensive among other sensors of this class and the data can be transferred using micro controller and an IoT module to nearest health care centers. © 2021 IEEE.Item Measurement and Evaluation of Human Vital Sign using 77GHz AWR1642 FMCW Radar Sensor(Institute of Electrical and Electronics Engineers Inc., 2021) Srihari, P.; Vandana, G.S.; Raghavendra, B.S.This paper proposes vital sign measurements of humans like heart rate (HR) and respiration rate (RR). The Texas Instruments AWR1642, frequency modulated continuous wave (FMCW) mmwave radar sensor, operating as 77-81 GHz frequency with 4GHz as the sweep bandwidth of the linear frequency modulated (LFM) waveform, is deployed to measure the HR and RR vital parameters. Here, twenty subjects (10 male; 10 female) experimental data has been collected using TI AWR1642 radar sensor, personal computer (PC), and DCA1000 data acquisition module. The HR and RR algorithm is applied to the process data to measure the HR and RR of these subjects. The male and female subjects' average HR is 78.587 and 77.827, respectively. Further, the average RR of the male and female subjects is 19.959 and 19.23, respectively. Furthermore, a pulse oximeter(POM) obtains HR ground truth information to validate the proposed method. The overall absolute mean error percentage(MEP) compared to pulse oximeter data is 4.7935% for 20 volunteers who have participated in the experiment. © 2021 IEEE.Item Intruder Detection and Tracking using 77GHz FMCW Radar and Camera Data(Institute of Electrical and Electronics Engineers Inc., 2022) Vandana, G.S.; Pardhasaradhi, B.; Srihari, P.Target detection and tracking using optical and radar sensors have many applications in surveillance. As the optical sensor helps to visualize the target and the radar can provide its range and velocity, their combination results in useful information for continuous monitoring and coherence. This paper presents a radar-camera experimental setup to detect and track intruders in a restricted area. A real-time experiment with different target speeds and various radar cross-sections(RCS) (1. A person running, 2. A cyclist, and 3. A motorcyclist). We deployed a 77GHz IWR1642BOOST FMCW (Frequency Modulated Continuous Wave) radar module as a radar unit and a phone camera with an aperture of f/1.79 as an optical sensor. The data collected from the radar and camera sensor are applied to detection and tracking modules to obtain target tracks. The radar provides the observations of range, Doppler, and angle information. These observations are used to estimate the state of the target via extended Kalman filtering(EKF), dBscan clustering, and global nearest neighbor(GNN) association, followed by track maintenance. The optical sensor provides video frames as input and output tracks via foreground detection, blob analysis, motion-based detection, Kalman filtering, and track maintenance. The experimental result shows that combining radar and optical sensors accomplishes tracking accuracy and coherence in target detection and tracking. © 2022 IEEE.Item An Experimental Evaluation of MIMO-SAR Imaging with FMCW Radar(Institute of Electrical and Electronics Engineers Inc., 2022) Sriharsha Nag, T.S.; Vandana, G.S.; Pardhasaradhi, B.; Srihari, P.Synthetic aperture radar (SAR) imaging is a widely used technique to generate two-dimensional and three-dimensional imaging based on the principle of moving sensors. This paper presents an experimental investigation of SAR imaging using an IWR6843ISK frequency modulated continuous waveform(FMCW) radar sensor on a moving platform and providing the stationary targets. In this experiment, the moving platform is used to recreate images with a higher spatial resolution based on a two-dimensional fast Fourier transform (2D-FFT) algorithm. Three different configurations are explored, namely: SAR, single input multiple output SAR (SIMO-SAR), and multiple input and multiple outputs SAR for imaging multiple targets within the vicinity. The real-time data is collected by moving the radar from 1-21m and observing two different stationary targets. The received data is processed using the 2D-FFT algorithm and obtaining the imaging for various configurations. The experimental results reveal that target detection is accomplished for all three configurations and comparable with ground truth. The MIMO-SAR outperforms and is a suitable candidate for automotive SAR imaging. © 2022 IEEE.Item DoA Estimation for Micro and Nano UAV Targets using AWR2243 Cascaded Imaging Radar(Institute of Electrical and Electronics Engineers Inc., 2022) Kavya, T.S.; Vandana, G.S.; Srihari, P.; Leelarani, V.; Pardhasaradhi, B.Frequency-modulated continuous wave (FMCW) radars accurately estimate the target's position and velocity, but the angular resolution is inadequate. The low radar cross section (RCS) unmanned aerial vehicles (UAVs) like micro UAVs (0.01m2) and nano UAVs (0.001m2) pose a significant threat to sensitive military and civilian installations. The DoA of the low RCS targets helps in making stealthy countermeasures. In this paper, the DoA of nano and micro UAVs is experimented using Texas instruments AWR2243 cascaded imaging radar in conjunction with a digital signal processing evaluation module (DSP EVM). The data is received from all the available 16 receivers, then the subspace method of multiple signal classification (MUSIC) algorithm is applied to estimate the DoA of the low RCS UAvs in hovering mode. The ground truth of the UAVs is fixed at 10m range and 12 ° azimuth from the center of the radar using engineering protractor. The average estimated DoA for nano and micro UAV s is 12.80° and 11.43°, respectively, for the ground truth DoA. The AWR2243 cascaded imaging radar provides superior performance and suitable candidate for the DoA estimation for micro and nano UAVs compared to existing AWR1642, IWR1642, and IWR6843 radars. © 2022 IEEE.Item Real Time Vital Sign Monitoring System using AWR1642 Radar Module with Remote Access(Institute of Electrical and Electronics Engineers Inc., 2022) Dayananda, B.N.; Vandana, G.S.; Srihari, P.; Pardhasaradhi, B.The remote access to vital sign measurements like pulse rate (PR) and breathing rate (BR) of a patient to doctors and family members makes it much more helpful in patient risk analysis. Texas Instruments AWR1642 frequency modulated continuous wave (FMCW) radar operates at 77-81 GHz frequency with 4 GHz sweep bandwidth for linear frequency modulated (LFM) waveform. In the literature, AWR1642 is used to determine a person's PR and BR in an offline mode. In this paper, the AWR1642 radar module is integrated with Raspberry Pi 4 Model B (Pi4B), and a network connection is established using SIM7600G-H 4G HAT and accessed through TeamViewer software. For this experiment, we have considered ten males and ten females in the age group of 19-52 years and 18-29 years, respectively. The male and female attendees' average PR is 84.84bpm and 79.9965bpm, respectively. The male and female attendees' average BR is 18.408bpm and 16.526bpm, respectively. Ground truth data is gathered from a fingertip pulse oximeter(PO) to verify our readings of PR and BR. The overall absolute mean error (AME) of PR and BR compared to the PO data is 0.6430 % and 4.2595% for the 20 volunteers who participated in the experiment. © 2022 IEEE.Item High Speed and Low Power DSP Architectures for Barker-13 Radar Pulse Compressor(Institute of Electrical and Electronics Engineers Inc., 2022) Anoopkumar, K.A.; Pardhasaradhi, B.; Vandana, G.S.; Rajeswari, R.; Srihari, P.This paper proposes two novel efficient DSP architectures for the Barker-13 sequence for radar coded waveform design. Firstly, the traditional pulse compressor architectures are modified by using unfolded DSP techniques to achieve higher sampling rates for high-speed applications. Secondly, the reduction in hardware utilization and power consumption are addressed by the folding technique. Further, the proposed architectures are implemented on Artex-7 Field Programmable Gate Arrays (FPGA). The hardware implementation results demonstrates that the unfolded pulse compressor increased the speed by 3.25 times compared to traditional broadcasting filter realization. On the other hand, the folded architecture reduced the power usage by 15.2% in comparison to broadcast architecture. These pulse compressors can be deployed for high speed and low power radar/sonar applications. © 2022 IEEE.Item SAR Imaging with Automotive Radar: Range Migration Algorithm, Experiment, and Future Directions in Automotive Vehicle(Institute of Electrical and Electronics Engineers Inc., 2022) Sriharsha Nag, T.S.; Vandana, G.S.; Pardhasaradhi, B.; Srihari, P.Synthetic Aperture Radar (SAR) imaging with air-borne radar has many applications in remote sensing, surface mapping, and civil infrastructure monitoring. In contrast, the Millimeter wave (mmWave) radars are confined to the automotive industry to fetch information like range, azimuth, and elevation. In this paper, we proposed configuring the mm-wave radar in SAR mode to utilize the availability of multiple transmitters and receivers. The frequency modulated continuous wave (FMCW) radar is ported onto a moving platform, and a range migration algorithm (RMA) is performed to perform SAR imaging. The real-time experiment was conducted using IWR6843ISK radar and explored different configurations like SAR, single-input multiple-outputs SAR (SIMO-SAR), and multiple-input multiple-outputs SAR (MIMO-SAR). In addition to that, the platform movement is also considered by varying the speed from slow to high. The acquired I-Q data is processed using a range migration algorithm (RMA) by following the processing steps like a two-dimensional fast fourier transform (2D-FFT), Stolt interpolation, azimuth compression, and inverse FFT (IFFT). The experimental results reveal that the target detection is accomplished for all the cases. The best results can be obtained for MIMO configuration with a high-speed moving platform. These results can be highly applicable for the automotive industry to perform SAR imaging on SRR radars which are being deployed on the side of the vehicle to monitor the guard rails, crossing vehicles, and VRU. © 2022 IEEE.Item FPGA Implementation of Moving Target Indicator Filter for FMCW Radar Data(Institute of Electrical and Electronics Engineers Inc., 2023) Sreelekha, N.; Vandana, G.S.; Srihari, P.; Leelarani, V.; Raju, M.K.; Sreenivasula Reddy, T.S.This study examines several digital finite impulse response (FIR) filter approaches for moving target indication (MTI) employing short-range FMCW radar sensors. The FIR filters can filter out low doppler shift responses from undesirable stationary targets. A 77 GHz AWR1642 FMCW radar sensor and a DCA1000 data capture card are used to build a hardware configuration. A single data frame (samples × chirps) containing a target approaching the radar is been considered. The recorded radar is preserved in a 256x64 matrix of in-phase and quadrature-phase components, which is then processed using various digital filters. The radar provides insights into doppler characteristics for the observations. This study proposes designing and implementing a two-tap and a three-tap FIR filter-based MTI processing module to reduce static targets. The VLSI DSP pipelining approach is deployed to improve filter performance regarding critical path delay and throughput. © 2023 IEEE.Item A Multiple Llyods Approach for LiDAR Point Cloud Quantization and Communication(Institute of Electrical and Electronics Engineers Inc., 2023) Dayananda, B.N.; Achala, G.; Srihari, P.; Raju, M.K.; Vandana, G.S.; Pardhasaradhi, B.The development and usage of drones and LiDARs have become common in forestry, archaeology, surveillance, and intruders in recent years. Even though both domains reached a very mature state, the usage, integration of LiDAR scanning from drones, security, and low bandwidth constraints are still fantasy. This paper proposed to use LiDAR on a drone to scan the area, quantize the point cloud, and communicate it to the ground station through free space communication. The purpose of open space communication rather than cloud-based solutions is to avoid related security threats. In addition, this paper uses Lloyds-based quantization to achieve optimality in the quantization scheme. Before transmitting the point cloud, it is proposed to quantize it in parallel optimal quantizers. As a result of the proposed quantizer model, we calculated the RMSE, bandwidth, and choice of communication module for this particular scenario. The quantization loss is shown in terms of RMSE, bandwidth, and channel capacity requirements depicted with some bits. RMSE value obtained in this work for the Lloyds quantization method is 0.899. The LiDAR point cloud data is transmitted to ground station with data rate of 21Mbps utilizing free space optical communication. © 2023 IEEE.