Multi-channel Data Acquisition Research Articles

Research on multi-channel data acquisition system of production index information based on genetic algorithm

Research on multi-channel data acquisition system of production index information based on genetic algorithm

Multi-Channel Low-Noise Analog Front Design

With the development of digital nuclear pulse processing technology, the requirements for the analog front-end circuit of digital energy spectrometers are getting higher and higher. Not only need to reduce the noise caused by the device as much as possible, but also need to meet the needs of multi-channel data acquisition. This article based on VGA (Variable Gain Amplifier) has designed a multi-channel low-noise analog front-end circuit to meet the functional requirements of the energy spectrometer while reducing the signal transmission in the analog front-end circuit as much as possible. The circuit noise is strictly controlled to ensure the signal-to-noise ratio of signal transmission. AD9255 is used for waveform digitization, and the input range is 100 μV-2 VPP. After testing, the circuit has a wider gain range and better noise control. Input 100 μVpp signal when the analog front-end gain is 24 dB, and its signal-to-noise ratio can reach 1:1.

Embedded Microprocessor Wireless Communication Data Collection Aids in Early Warning of Default Risk for Internet Finance Bank Customers

Thanks to the maturity and innovation of embedded technology, products based on embedded platforms continue to penetrate people’s lives and play a pivotal role in various fields of society, while the development of data acquisition systems based on wireless communication of embedded microprocessors is one of the frontier directions of embedded development. Modern commercial bank risk management system includes risk control organization, risk measurement techniques (including risk warning), risk avoidance techniques, and total risk management model. In this paper, a multichannel data acquisition system combined with a wireless sensor platform is designed for early warning of default risk of Internet financial bank customers, which can realize real‐time monitoring, acquisition, display, and data storage of DC signals and indoor environment information output from sensor platforms or electronic devices, and for frequent transactions, fund splitting, and mortgage pledging related to complex customers in today’s e‐commerce platform, which triggers when the associated enterprise credit risk presents complexity, continuity, wholeness, multiplicity, volatility, severity, etc., it is used to improve risk judgment and risk warning ability, enhance investment risk response ability, and reduce the related losses caused by marketing risk.

Crosstalk Effects in the Uncertainty Estimation of Multiplexed Data Acquisition Systems

This article deals with the analysis of multichannel data-acquisition systems with the aim of identifying and combining the main uncertainty contributions according to the guide to the expression of uncertainty in measurement (GUM) framework. Particular attention has been paid toward crosstalk effect, which could be an important uncertainty contribution in multiplexed data-acquisition systems. The uncertainty analysis is described for three commercial data acquisition devices highlighting that crosstalk specifications are often not suitable for reliable uncertainty estimation in operating conditions. For this reason, an experimental setup has been arranged to fully characterize the interchannel effects of the investigated devices. The obtained results have highlighted that proper characterization of a data-acquisition system is effective in estimating the actual performance at the frequency of interest and in the operating conditions for the source resistance and the input-channel configuration. Eventually, a customized procedure has been proposed, which is effective in correcting the crosstalk effects also in very severe conditions of interchannel disturbance.

Multi-channel observation experiments of audio-frequency magnetotelluric technology in shallow water

Geophysical electromagnetic (EM) surveys for imaging the subsurface structure under lakes, rivers, or other water bodies have attracted increasing attention. Based on forward modeling and field experiments, a boat-towed audio-frequency magnetotelluric (AMT) multi-channel observation system for shallow fresh water was developed preliminarily. Through the development of water electrodes and the streamer cable, a boat-towed multi-channel data acquisition cable was developed. We carried out a variety of different comparative experiments, such as water- and land-AMT experiments, different polar-distances, and acquisition time-length experiments, and observation experiments at different time, in ditches or rivers around the Qilihai Wetland, Tianjin, China. We also carried out profile detection experiments using this system in southern Baiyang Lake, Xiongan New Area, China. The experimental results demonstrate that the proposed water–AMT system can be utilized to characterize subsurface structure underneath shallow water areas, advancing the potential of geophysical surveys on rivers or lakes.

Subsampling Approaches for Compressed Sensing with Ultrasound Arrays in Non-Destructive Testing.

Full Matrix Capture is a multi-channel data acquisition method which enables flexible, high resolution imaging using ultrasound arrays. However, the measurement time and data volume are increased considerably. Both of these costs can be circumvented via compressed sensing, which exploits prior knowledge of the underlying model and its sparsity to reduce the amount of data needed to produce a high resolution image. In order to design compression matrices that are physically realizable without sophisticated hardware constraints, structured subsampling patterns are designed and evaluated in this work. The design is based on the analysis of the Cramér–Rao Bound of a single scatterer in a homogeneous, isotropic medium. A numerical comparison of the point spread functions obtained with different compression matrices and the Fast Iterative Shrinkage/Thresholding Algorithm shows that the best performance is achieved when each transmit event can use a different subset of receiving elements and each receiving element uses a different section of the echo signal spectrum. Such a design has the advantage of outperforming other structured patterns to the extent that suboptimal selection matrices provide a good performance and can be efficiently computed with greedy approaches.

Intelligent Mobile Electronic Nose System Comprising a Hybrid Polymer-Functionalized Quartz Crystal Microbalance Sensor Array.

We devised a low-cost mobile electronic nose (e-nose) system using a quartz crystal microbalance (QCM) sensor array functionalized with various polymer-based thin active films (i.e., polyacrylonitrile, poly(vinylidene fluoride), poly(vinyl pyrrolidone), and poly(vinyl acetate)). It works based on the gravimetric detection principle, where the additional mass of the adsorbed molecules on the polymer surface can induce QCM resonance frequency shifts. To collect and process the obtained sensing data sets, a multichannel data acquisition (DAQ) circuitry was developed and calibrated using a function generator resulting in a device frequency resolution of 0.5 Hz. Four prepared QCM sensors demonstrated various sensitivity levels with high reproducibility and consistency under exposure to seven different volatile organic compounds (VOCs). Moreover, two types of machine learning algorithms (i.e., linear discriminant analysis and support vector machine models) were employed to differentiate and classify those tested analytes, in which classification accuracies of up to 98 and 99% could be obtained, respectively. This high-performance e-nose system is expected to be used as a versatile sensing platform for performing reliable qualitative and quantitative analyses in complex gaseous mixtures containing numerous VOCs for early disease diagnosis and environmental quality monitoring.

Milling performance of titanium alloy based on short electric arc machining with direct current power source

In this study, we have proposed the use of direct current (DC) power source instead of pulsed power source for solving the problems of low material removal rate (MRR), high relative tool wear ratio (RTWR), and high specific energy consumption (SEC) in short electric arc machining (SEAM). The performance of SEAM with DC was significantly improved as compared to that with medium frequency pulse (MFP). The MRR of Ti6Al4V alloy during SEAM with DC exceeded 15100 mm3/min and the ideal MRR exceeded 60000 mm3/min. Further, the RTWR and SEC were 0.7% and 36.6 kJ/cm3, respectively. The influence of tool electrode polarity and voltage on MRR, RTWR, SEC, and surface roughness were studied. The current and voltage during the entire process were measured by DEWESoft SIRIUSi multi-channel data acquisition system. Moreover, the surface morphology, cross section, chemical composition, and micro-hardness of Ti6Al4V after machining were also investigated.

Research and Development of Measurement and Control System of New Energy Vehicle Computer Technology Test Bed

At present, with the increasingly prominent environmental problems, the automobile industry is gradually transforming to meet the increasingly stringent environmental requirements, and more and more new energy vehicles are put into use. This paper analysis the function of the new energy automobile test-bed: after combined with computer technology, research and development of multi-channel real-time dynamic data acquisition and analysis system. Finally the article discusses the combination of computer technology test measurement and control system design are verified. It provides a reference for measurement and control research of new energy automobile test-bed.

Ultralow energy photoacoustic microscopy for ocular imaging in vivo.

.Significance: The development of ultralow energy photoacoustic microscopy (PAM) on the clinically relevant pigmented rabbit eye model paves a road toward translation of the emerging PAM technology in ophthalmology clinics.Aim: Since the eye is particularly vulnerable to laser damage, we aim to develop an ultralow energy PAM system to significantly improve the laser safety of PAM by increasing the sensitivity of the system and reducing the incident laser energy for imaging.Approach: A multichannel data acquisition circuit with two-stage signal amplification was specially designed, which, in combination with the application of 3 by 3 median filter in the spatial domain, significantly improved the signal-to-noise ratio of the PAM system. The safety of this system was validated by histopathology, fluorescein angiography, and fundus photography.Results: Experiments performed on pigmented rabbits demonstrated that, when using this ultralow energy PAM system, satisfactory image quality can be achieved in the eye with an incident laser fluence that is only 1% of the American National Standards Institute safety limit. Fundus photography, fluorescein angiography, and histopathology were performed after the imaging procedure, and no retinal or ocular damage was observed.Conclusions: The proposed ultralow energy PAM system has excellent safety and holds potential to be developed into a clinical tool for ocular imaging.

Vision-Based Vehicle Detection for VideoSAR Surveillance Using Low-Rank Plus Sparse Three-Term Decomposition

Automatic vehicle detection from a video synthetic aperture radar (VideoSAR) system presents significant potential to enhance the surveillance performance in dynamic region of interest (DROI). In this paper, a novel VideoSAR low-rank plus sparse decomposition (LRSD) perspective for single-channel single-pass configuration is proposed to track the ground defocusing vehicles. Vehicle imaging features with 2-D motion parameters are derived theoretically by exploiting a priori knowledge of polar format algorithm (PFA). In accordance with the revealed characteristics, a vision-based VideoSAR-LRSD algorithm, called three-term decomposition (TTD) with proximal exchange-based alternating directions method of multipliers (PEADMM), is then proposed to improve the performance of vehicle detection. It can be used to break the limitation for the application of emergency response not permitting the acquisition of multi-channel or multi-pass data. We comprehensively demonstrate using extensive VideoSAR DROI experiments that in comparison with the state-of-the-art algorithms, TTD-PEADMM algorithm presents the improved accuracy and is able to offer competitive results.

Special software design for data acquisition and experi-mental database management of electromagnetic launch system

Electromagnetic launching system is composed of the Electromagnetic Railgun (EMRG) and the large-scale Pulse Power System (PPS). According to the different test requirements of PPS and EMRG, the special master-slave distributed data acquisition software for electromagnetic launching system is designed by using LabVIEW graphic language. The test host and the sub-machines are multi-channel transient data acquisition systems based on PXI bus. The host PXI is used to measure the comprehensive parameters of the EMRG in multi-physical field. All sub-PXIs are used to diagnose the discharge current signals of each Pulse Forming Unit (PFU). The database management software uses C# programming language to design a friendly human-computer interaction interface, and uses SQL Server software to establish and manage the database, which realizes the comprehensive management of experimental data, tasks and resources involved in the EMRG experiments. The experimental information and experimental data are classified and filed, and the experimental data can be queried, and the experimental results can be analyzed and compared. The data acquisition and experimental database management software has perfect functions, friendly user interface, convenient operation, good versatility, and can also be used in other experimental occasions.

Multi-Channel Data Acquisition System Based on FPGA and STM32

In order to realize the acquisition and storage of underwater acoustic signals for aiming at the requirements of multi-channel, low power consumption and small volume for underwater receiver extension of sonar system, a multi-channel signal acquisition and storage system based on FPGA and STM32 with variable number of working channels and sampling frequency is designed, in which the system is consisted of 8 pieces, 8 channel and 24 bits high dynamic range Δ-Σ ADS1278 ADC chip to synchronous multi-channel analog signal acquisition. FPGA, as the acquisition sequence and logic control, reads and collates the ADC chip data and writes it into the internal high-capacity FIFO, and adds corresponding operations according to the characteristics of FIFO in an application. SMT32 single-chip microcomputer reads the FIFO data through the high-speed SPI interface with FPGA and writes the multi-channel data into the high-capacity SD card. The testing results have verified that the system has characteristics such as stable and reliable, easy configuration, low power consumption, can guarantee the multichannel data serial transmission, storage, accurate, up to 64 analog signals at the same time the real-time collection and storage, top 20 kHz sampling rate, the system total power of the system of about 3W, data rates up to 100 Mb/s, fully meet the needs of underwater sound acquisition system.

A Multi-Sample and Multi-Channel Technique for Electrochemical Testing and Corrosion Evaluation

Abstract A potentiostat/galvanostat system is used for conducting electrochemical experiments in aqueous environments. The conventional method is to use one sample for investigation in each experiment. To maximize the usage of a single unit electrochemical testing system, a multi-sample and multi-channel technique was developed to concurrently test multiple metal samples. This article provides detailed information on (a) preparation of a multi-sample testing piece as the working electrode of the electrochemical system, (b) configuration of a multi-channel data acquisition system for recording data when running a test, and (c) separation of data channels by posttest data processing. This technique allows the electrochemical system to study the corrosion behavior of multiple samples in the same testing solution under the same conditions, so that the accuracy of material comparison can also be significantly improved.

An improved method to detect coronary artery disease using phonocardiogram signals in noisy environment

Identification of coronary artery disease (CAD) from phonocardiogram (PCG) signal is a low signal to noise ratio (SNR) problem. This study proposes a PCG based CAD detection system robust against the environmental noise that does not require additional reference signals for noise acquisition and PCG segmentation. Here, the experiments are conducted on 40 CAD and 40 normal subjects. PCG signals are recorded from a multichannel data acquisition system from four auscultation sites on the left anterior chest. While heart sounds are propagated to different auscultation sites with a certain delay, the ambient noise appearing at microphone array are not mutually time-lagged. Thus, we propose to use the imaginary part of cross power spectral density (ICPSD) to capture the spectrum of heart sounds as it is unresponsive to zero time-lagged signals. Subband based spectral features obtained from ICPSD are classified in a machine learning framework. The performance of the system is studied in the presence of babble, vehicle and white noise in which useful information were extracted from both systolic and diastolic phases of cardiac cycle. The proposed method achieves accuracy, sensitivity and specificity of 74.98%, 76.50% and 73.46%, respectively in absence of ambient noise for k-fold (k=5) cross-validation. The accuracy for 0 dB SNR in presence of white, babble and vehicle noise were 71.13%,66.47% and 69.60%, respectively. The proposed method was found to be superior in CAD classification when compared with existing noise removal based approach. The present work shows the potential of developing a PCG-based multichannel CAD detection system as an affordable point of care device for real-life use, where a certain amount of ambient noise is expected.

Multi-Channel and Simultaneous Data Acquisition System for Magnetic Tensor Detection

This paper reports the design of a multi-channel and simultaneous data acquisition system(MSDAS). It can collect 12-channel magnetic induction component signals with magnetic tensor information rapidly and simultaneously. The STM32F103RCT6 and a 16-bit AD7606 are used as the MSDAQ’s microcontroller and the analog-to-digital(A/D) converter, respectively. Moreover, FATFS file system and TCP/IP protocol are integrated such that the MSDAS is capable of local storage and network simultaneous data transmission in real time. Experiments show that MSDAS can achieve data acquisition error ≤0.5% with the simultaneous sampling rate up to 500Hz. It is verified that the measurement results of magnetic tensor are basically consistent with the theory.

Design of Multi-channel data acquisition system based on single Chip computer and LabVIEW

Labview is a graphical programming language that creates applications with icons instead of text lines. Because the traditional data acquisition system based on single chip computer is not supported by the upper computer, its storage capacity is limited, no matter what kind of data memory is used, so it has to overwrite and refresh the stored historical data. This system uses the lower computer to collect the analog data, and from the single chip computer to collect the eight channels of data, and to answer the command sent by the host. The host computer is responsible for processing and displaying the received digital quantity. The host and slave communicate with each other using RS-232. The paper presents design of Multi-channel data acquisition system based on single Chip computer and LabVIEW.

Research on Measurement and Control System of New Energy Vehicle Test Bench

New energy vehicles can alleviate the environment and energy pressure, promote the rapid upgrading and transformation of the automobile industry, and have a major impact on China’s technological economy and environmental improvement. However, at present, China’s new energy vehicle technology is still in its infancy, and there are still bottlenecks in the development of complete vehicles and parts. How to break through technical barriers and research new technologies has become a key factor in the introduction of new energy vehicles into the market. Based on this, the paper builds a new energy vehicle experimental platform, and develops a real-time online multi-channel data acquisition and analysis system based on Lab VIEW. Combined with the D2P Moto Hawk development platform, the electronic control of the test platform is realized. The final development of the measurement and control system enables dynamic monitoring of the test bench, fault alarms and control of key components.

Design and Implementation of an Arduino-Based Plug-and-Play Acquisition System for Seismic Noise Measurements

The analysis of seismic noise provides a reliable estimation of the soil properties, which supposes the starting point for the assessment of the seismic hazard. The horizontal-to-vertical spectral ratio technique calculates the resonant frequency of the soil just by using a single three-component sensor. Array measurements require at least several vertical sensors registering simultaneously and their analysis provides an estimation of the surface waves dispersion curve. Although these methods are relatively cheaper than other geotechnical techniques, the cost of the sensors and the multi-channel data acquisition system means that small research groups cannot afford this kind of equipment. In this work, two prototypes for registering seismic noise have been developed and implemented: a three-channel acquisition system, optimized for working with three-component sensors; and a twelve-channel acquisition system, prepared for working simultaneously with twelve vertical geophones. Both prototypes are characterized by being open-hardware, open-software, easy to implement, and low-cost. The main aim is to provide a data acquisition system that can be reproduced and applied by any research group. Both developed prototypes have been tested and compared with other commercial equipment, showing their suitability to register seismic noise and to estimate the soil characteristics.

Toward Wearable Healthcare: A Miniaturized 3D Imager With Coherent Frequency-Domain Photoacoustics.

Medical monitoring is undergoing a translation from the hospital-based system to the personalized home-based system. With the aim of wearable application of photoacoustic technique, we propose a miniaturized photoacoustic 3D imager for superficial medical imaging. By employing the compact continuous-wave laser diode based optical irradiation and an ultrathin 2D matrix array based photoacoustic detection in the coherent frequency domain, a wearable imaging probe with a size of about 80 × 25 × 24mm3 and a weight of 21 g is developed. At the backend, an FPGA controlled Howland current source drives the laser diodes to excite linear frequency modulated optical irradiation. Recorded by a portable multichannel data acquisition system, the generated photoacoustic responses are firstly compressed with the coherent frequency domain photoacoustic method and then extrapolated in the wavenumber-frequency domain for fast image reconstruction. With three-wavelength (450nm, 638nm, and 808nm) laser irradiation, photoacoustic imaging can be operated multispectrally, endowing the developed imager with functional imaging capability in 3D space. With the imager worn on the human forearm, hemoglobin oxygen saturation level in superficial arm vasculature can be long-term monitored with high stability. When the imager is applied for imaging in a relatively large area (e.g., early melanoma detection in the human breast), flexible scanning in a handheld manner can be performed. This work opens the application potential of photoacoustic technique in a broad range of areas, including personalized healthcare, home health monitoring, and long-term physiologic monitoring.