This paper reports the design, proof-of-concept implementation and preliminary performance assessment of a lowcost, real-time, portable, low power, and small form factor GNSS rebroadcaster. This device can be used bot...
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ISBN:
(纸本)9781665416160
This paper reports the design, proof-of-concept implementation and preliminary performance assessment of a lowcost, real-time, portable, low power, and small form factor GNSS rebroadcaster. This device can be used both as a GNSS signal generator and as a GNSS signal regenerator. This device can be used to test the addition of new features in GNSS signals, such as new signals for ranging, and to characterize the performance of new and existing spoofing countermeasures for GNSS receivers in real time. This device does not require the use of post-processed GNSS signals, enabling the testing with live signals, for instance in a vehicular test campaign replicating the correct dynamic and channel impairments.
This paper presents the design and implementation of Modular Multilevel Inverter (MMI) to control the Induction Motor (IM) drive using intelligent techniques towards marine water pumping applications. The proposed inv...
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This paper presents the design and implementation of Modular Multilevel Inverter (MMI) to control the Induction Motor (IM) drive using intelligent techniques towards marine water pumping applications. The proposed inverter is of eleven levels and has the ability to control the speed of an IM drive which is fed from solar photovoltaics. It is estimated that the energy consumed by pumping schemes in an onboard ship is nearly 50% of the total energy. Considering this fact, this paper investigates and validates the proposed control design with reduced complexity intended for marine water pumping system employing an induction motor (IM) drive and MMI. The analysis of inverter is carried out with Proportional-Integral (PI) and Fuzzy Logic (FL) based controllers for improving the performance. A comparative analysis has been made with respect to better robustness in terms of peak overshoot, settling time of the controller and Total Harmonic Distortion (THD) of the inverter. Simulations are undertaken in MATLAB/Simulink and the detailed experimental implementation is conducted with field programmable gate array (FPGA). The results thus obtained are utilized to analyze the controller performance, improved inverter output voltage, reliable induction motor speed control and power quality improvement by reduction of harmonics. The novelty of the proposed control scheme is the design and integration of MMI, IM drive and intelligent controller exclusively for marine water pumping applications.
Spiking neural networks (SNNs) have been getting more research attention in recent years as the way they process information is suitable for building neuromorphic systems effectively. However, realizing SNNs on hardwa...
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Spiking neural networks (SNNs) have been getting more research attention in recent years as the way they process information is suitable for building neuromorphic systems effectively. However, realizing SNNs on hardware is computationally expensive. To improve their efficiency for hardware implementation, a field-programmablegatearray (FPGA) based SNN accelerator architecture is proposed and implemented using approximate arithmetic units. To identify the minimal required bit-width for approximate computation without any performance loss, a variable precision method is utilized to represent weights of the SNN. Unlike the conventional reduced precision method applied to all weights uniformly, the proposed variable precision method allows different bit-widths to represent weights and provide the feasibility of maximizing truncation effort for each weight. Four SNNs adopting different network configurations and training datasets are established to compare the performance of proposed accelerator architecture using the variable precision method with the proposed one using the conventional reduced precision method. Based on the experimental results, more than 40% of the weights require less bit-width when applying the variable precision method instead of the reduced precision method. With the variable precision method, the proposed architecture achieves 28% fewer ALUTs and 29% less power consumption than the proposed one using the reduced precision method. (C) 2021 Elsevier Inc. All rights reserved.
The reversible computation is the process of designing the architecture with reversible logic gates (RLG) and applicable for optical computing, digital signal processing, nanotechnologies and low-power circuits. In th...
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The reversible computation is the process of designing the architecture with reversible logic gates (RLG) and applicable for optical computing, digital signal processing, nanotechnologies and low-power circuits. In this study, integer wavelet transform (IWT) compression technique is applied to the input image to compress the pixel value. The utilization of the IWT is used to improve the quality of the image in terms of peak signal-to-noise ratio (PSNR) and structural similarity index matrix (SSIM). In addition, different types of RLGs are used to perform the encryption and decryption of the images. A random number is generated using the Lorenz chaotic system (LCS) that contains three different stages and each stage is developed using arithmetic blocks. Here, an effective key value is generated from the input image values by connecting the LCS's output with the heterogeneous key generation (HKG) module. The inverse IWT (IIWT) technique is used to retrieve the original data during execution of decryption operation. Application specific integrated circuit and field-programmablegatearray (FPGA) performances are calculated for reversible logic cryptographic design (RLCD) IWT-HKG architecture. The results showed that it has achieved better performance compared to conventional methods. Moreover, security analyses such as avalanche effect, side channel attack and session key agreement are performed for the RLCD-IWT-HKG method. The RLCD-IWT-HKG method has achieved 89 LUTs, 52 flip flops and 31 slices for the Virtex 6 FPGA device. After retrieving the decrypted images, values of PSNR and SSIM are evaluated as 39.90 dB and 0.6874, respectively.
This study focuses on a high-speed permanent magnet synchronous motor (PMSM) drive system based on direct torque control (DTC) implemented in a field programmable gate array (FPGA). DTC is difficult to start and opera...
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ISBN:
(纸本)9781665493024
This study focuses on a high-speed permanent magnet synchronous motor (PMSM) drive system based on direct torque control (DTC) implemented in a field programmable gate array (FPGA). DTC is difficult to start and operate in low speed region because of stator flux estimation based on time integration of the induced voltage. Voltage error due to dead time of the inverter affects estimation and control characteristics. This paper shows influence of dead-time compensation on starting characteristics of high speed PMSM.
To fulfil the tight area and memory constraints in IoT applications, the design of efficient Convolutional Neural Network (CNN) hardware becomes crucial. Quantization of CNN is one of the promising approach that allow...
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To fulfil the tight area and memory constraints in IoT applications, the design of efficient Convolutional Neural Network (CNN) hardware becomes crucial. Quantization of CNN is one of the promising approach that allows the compression of large CNN into a much smaller one, which is very suitable for IoT applications. Among various proposed quantization schemes, Power-of-two (PoT) quantization enables efficient hardware implementation and small memory consumption for CNN accelerators, but requires retraining of CNN to retain its accuracy. This paper proposes a two-level post-training static quantization technique (DoubleQ) that combines the 8-bit and PoT weight quantization. The CNN weight is first quantized to 8-bit (level one), then further quantized to PoT (level two). This allows multiplication to be carried out using shifters, by expressing the weights in their PoT exponent form. DoubleQ also reduces the memory storage requirement for CNN, as only the exponent of the weights is needed for storage. However, DoubleQ trades the accuracy of the network for reduced memory storage. To recover the accuracy, a selection process (DoubleQExt) was proposed to strategically select some of the less informative layers in the network to be quantized with PoT at the second level. On ResNet-20, the proposed DoubleQ can reduce the memory consumption by 37.50% with 7.28% accuracy degradation compared to 8-bit quantization. By applying DoubleQExt, the accuracy is only degraded by 1.19% compared to 8-bit version while achieving a memory reduction of 23.05%. This result is also 1% more accurate than the state-of-the-art work (SegLog). The proposed DoubleQExt also allows flexible configuration to trade off the memory consumption with better accuracy, which is not found in the other state-of-the-art works. With the proposed two-level weight quantization, one can achieve a more efficient hardware architecture for CNN with minimal impact to the accuracy, which is crucial for IoT applicati
The development of Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, has introduced revolutionary changes in many areas over the past few years. However, aside from opening new possibilities, the usage ...
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The development of Unmanned Aerial Vehicles (UAVs), commonly referred to as drones, has introduced revolutionary changes in many areas over the past few years. However, aside from opening new possibilities, the usage of drones in an irresponsible and dangerous manner leads to many hazardous incidents. This paper presents a drone detection sensor with a continuous 2.400 GHz-2.483 GHz operational frequency range for detection methods based on passive radio frequency imaging techniques. The implementation based on Software Defined Radio (SDR) and fieldprogrammable Logic array (FPGA) hardware that overcomes the 40 MHz real-time bandwidth limit of other popular SDRs is presented utilizing low-cost off-the-shelf components. Furthermore, a hardware realization of the signal processing chain for specific detection algorithms is proposed to minimize the throughput between SDR and the companion computer and offload software computations. The device validation is made in a laboratory and real-life scenario and presented in relation to the sensor used in other works. In addition to the increased real-time bandwidth, the measurements show a 9 dB reduction in detection sensitivity compared to the reference receiver, in line with the analog RF front-end specifications. The final analysis demonstrates the proposed device's relevance as a sensor for obtaining machine learning datasets and as a part of a final anti-drone system.
In this article, an improved particle swarm optimization (PSO)-based variational mode decomposition (VMD) is proposed to compute the most informative band-limited intrinsic mode function (BLIMF) of highly nonstationar...
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In this article, an improved particle swarm optimization (PSO)-based variational mode decomposition (VMD) is proposed to compute the most informative band-limited intrinsic mode function (BLIMF) of highly nonstationary single as well as combined power quality events (PQEs). A novel reduced deep convolutional neural network (RDCNN) embedded with stack autoencoder, that is, RDCSAE structure is introduced to extract the most discriminative unsupervised feature data by importing the selected BLIMF of parameter-adaptive VMD (PAVMD) algorithm. A supervised robust multikernel random vector functional link network (RMRVFLN) method is proposed to further train the unsupervised features combined with the deep convoluted Fourier privileged data for the recognition of complex PQEs accurately. Automatic computation of minimum overlapped descriptive features, unified complex feature learning framework, outstanding recognition accuracy, robust antinoise performance, and quick PQEs recognition time prove the superiority of the proposed PAVMD-RDCSAE-RMRVFLN method over RDCNN, PAVMD-RDCNN, PAVMD-RDCSAE, PAVMD-RDCNN-RMRVFLN, and PAVMD-RDCSAE-MRVFLN methods. Finally, the architecture of the proposed method is designed, implemented, and tested in a fast digital field-programmablegatearray (FPGA) embedded processor to validate the feasibility, practicability, and performances for the online PQEs monitoring.
The existing programmable Logic Controller (PLC) based on microprocessors (mu p) or micro-controllers (mu c) are commonly used in the industry for various instrumentation and control applications. PLC exhibits limitat...
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The existing programmable Logic Controller (PLC) based on microprocessors (mu p) or micro-controllers (mu c) are commonly used in the industry for various instrumentation and control applications. PLC exhibits limitations such as less flexibility, poor scanning time, slower speed, and degraded response for high-speed industrial applications due to its fixed hardware and serial execution mechanism. A new field programmable gate array (FPGA) based PLC multi-channel High Speed Counter (HSC) module has been proposed, enhancing performance and flexibility compared to the existing PLC-HSC module. The proposed FPGA-PLC-HSC module has a 2-phase 2-Input counter with resolutions of 1X, 2X, and 4X which improve performance in terms of accuracy for position speed, and direction measurement applications. The FPGA-PLC-HSC module is implemented with the feedback node method and the shift register method inside LabVIEW FPGA along with device utilization. The simulation results show that the FPGA-PLC-HSC module has faster scanning time, good linearity, better resolution, maximum supporting input frequency, and counting frequency. For experimental purposes, an optical encoder M110960 (E8P 512 118 S D M B) with a signal conditioning circuit is connected to the NI-myRIO-1900 FPGA platform. The experimental results point out that the proposed FPGA-PLC-HSC module offers faster scanning time, better accuracy and linearity in 1X, 2X, and 4X resolution. (C) 2021 ISA. Published by Elsevier Ltd. All rights reserved.
Compressed sensing-based radio frequency signal acquisition systems call for higher reconstruction speed and low dynamic power. In this study, a novel low power fast orthogonal matching pursuit (LPF-OMP) algorithm is ...
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Compressed sensing-based radio frequency signal acquisition systems call for higher reconstruction speed and low dynamic power. In this study, a novel low power fast orthogonal matching pursuit (LPF-OMP) algorithm is proposed for faster reconstruction of sparse signals from their compressively sensed samples and the reconstruction circuit consumes very low dynamic power. The searching time to find the best column is reduced by reducing the number of columns to be searched in successive iterations. A novel architecture of the proposed LPF-OMP algorithm is also presented here. The proposed architecture is implemented on field programmable gate array for demonstrating the performance enhancement. Computation of pseudoinverse in OMP is avoided to save time and storage requirement to store the pseudoinverse matrix. The proposed design incorporates a novel strategy to stop the algorithm without consuming any extra circuitry. A case study is carried out to reconstruct the RADAR test pulses. The design is implemented for K = 256, N = 1024 using XILINX Virtex6 device and supports maximum of K/4 iterations. The proposed design is faster, hardware efficient and consumes very less dynamic power than the previous implementations of OMP. In addition, the proposed implementation proves to be efficient in reconstructing low sparse signals.
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