Design Of Sensor System Research Articles

Sum of heterogeneous blind zones predict movements of simulated groups

Simulation models regarding groups of fish and birds based on individual movement decision rules have become increasingly sophisticated. Recent studies have started to tie together how the rules of homogeneous independent-acting individuals lead to emergent group behaviors. However, there is less research on the role that heterogeneity within a group has on these emergent properties. Heterogeneity in real animal groups due to hunger, sex, body size, species, and age can influence speed, nearest neighbor distance, and viewing angle. In our study we examine how differences in viewing angle (or its complement: blind zone) within a group influence emergent properties such as group size, polarization, group shape, and segregation. Simulated groups were assembled with different mixes of blind zones (e.g. half the members with a blind zone of 60 degrees and half with a blind zone of 120 degrees). Significant differences in many of the measured emergent properties were found and were related to the level of heterogeneity as well as the absolute value of the blind zone. In homogeneous groups, increased values for the blind zone led to groups that were: smaller, more elongated, and denser. In heterogeneous groups the sum of blind zones predicted emergent group behaviors. Specifically, as the sum of the blind zones increased: group size and density decreased and the shape of the group became rounder. However, several mixes produced emergent properties that were very different than the predicted regressions. Our findings suggest that it will be important for researchers to look at how individual differences in blind zones within real groups such as fish schools and bird flocks influence emergent behaviors. Our findings also have applications to designing sensor systems for car navigation systems and robotic arrays.

Design of a soft sensor system for Puerarin extraction based on SVM

Design of a soft sensor system for Puerarin extraction based on SVM

Strain Transfer Analysis of Surface-Bonded MEMS Strain Sensors

The transmission of strain fields in adhesively bonded MEMS strain sensors is analyzed. In strain sensors that are attached to host structures using adhesive layers such as epoxy, complete strain transfer to the sensor is hindered due to the influence of the adhesive layer on the transfer. This paper presents an analytical model, validated by finite element method simulation, to provide insight and accurate formulation for strain transfer mechanism for bonded sensors. A shear-lag parameter has been introduced to account for the component geometry and properties. The model is capable of predicting the strain transmission ratio through a sensor gauge factor, and it clearly establishes the effects of the flexibility, length, and thickness of the adhesive layer and MEMS sensor substrate. Finally, modifications to sensor substrates, by the implementation of micromachined tapered edges and trench etching, are proposed in order to increase the strain transmission ratio. It has been found, for the selected case study, that the sensor sensitivity could be enhanced by up to 30%. This work on bonding analysis is applicable for performance prediction and calibration in sensor systems design.

A review on recent development of vibration-based structural robust damage detection

The effect of structural uncertainties or measurement errors on damage detection results makes the robustness become one of the most important features during identification. Due to the wide use of vibration signatures on damage detection, the development of vibration-based techniques has attracted a great interest. In this work, a review on vibration-based robust detection techniques is presented, in which the robustness is considerably improved through modeling error compensation, environmental variation reduction, denoising, or proper sensing system design. It is hoped that this study can give help on structural health monitoring or damage mitigation control.

Analysis and Design of a Homing Sensor System for a 2D Moving Platform with Nanometer Resolution

The nanotechnology field has been developing strongly in recent years and ultra-precision measuring systems are nowadays required. A new two-dimensional moving platform with 50x50mm range of travel, nanometer resolution and sub micrometer accuracy is being designed by the authors in order to be integrated with an Atomic Force Microscope (AFM). In this work the definition, design and experimental characterization of a homing sensor system for this 2D moving platform is presented. The homing sensor system will allow the generation of an absolute reference for the 2D platform on the X-Y axis and in θz, rotation of the XY plane in the Z axis, defining an initial cero for the measuring system which is based on laser encoders.

The Daft Approach for in Silico Prediction of Transmembrane Peptide Complexes

Transmembrane helix-helix interactions play a vital role in signaling, and the details of the complexes involved are a valuable complement to biochemical studies. Unfortunately, it is difficult to obtain structural models experimentally, and computational approaches such as protein-protein docking are problematic due to the membrane environment. Here we present an innovative method that combines coarse-grained molecular dynamics simulations, without biasing potentials, with a docking approach to quickly sample the interaction energy landscape. Starting structures are set up using schemes specific for the number of components, promoting encounters, and processed using a fully automated MARTINI-based workflow, facilitating high-throughput simulations.The method has been applied to ErbB1/ErbB2 homo- and heterodimers, validating the results against available experimental data. In addition, the method was used to investigate temperature controlled signaling by the DesK derived minimal sensor, and to provide a view on the interplay of TM dimers and trimers involved in TNF receptor activation. The results give insight in the mechanisms underlying signaling by simple transmembrane helix systems. This insight offers opportunities for the design of custom membrane-based sensor systems and for assessment of signaling by more complicated helix based systems.View Large Image | View Hi-Res Image | Download PowerPoint Slide

A Low-Cost, Portable, High-Throughput Wireless Sensor System for Phonocardiography Applications

This paper presents the design and testing of a wireless sensor system developed using a Microchip PICDEM developer kit to acquire and monitor human heart sounds for phonocardiography applications. This system can serve as a cost-effective option to the recent developments in wireless phonocardiography sensors that have primarily focused on Bluetooth technology. This wireless sensor system has been designed and developed in-house using off-the-shelf components and open source software for remote and mobile applications. The small form factor (3.75 cm × 5 cm × 1 cm), high throughput (6,000 Hz data streaming rate), and low cost ($13 per unit for a 1,000 unit batch) of this wireless sensor system make it particularly attractive for phonocardiography and other sensing applications. The experimental results of sensor signal analysis using several signal characterization techniques suggest that this wireless sensor system can capture both fundamental heart sounds (S1 and S2), and is also capable of capturing abnormal heart sounds (S3 and S4) and heart murmurs without aliasing. The results of a denoising application using Wavelet Transform show that the undesirable noises of sensor signals in the surrounding environment can be reduced dramatically. The exercising experiment results also show that this proposed wireless PCG system can capture heart sounds over different heart conditions simulated by varying heart rates of six subjects over a range of 60–180 Hz through exercise testing.

Random laser speckle based modulation transfer function measurement of midwave infrared focal plane arrays

Direct measurement of the modulation transfer function (MTF) of focal plane arrays (FPAs) using random laser speckle approaches for the visible/near-infrared wavelength band has been well documented over the last 20 years. These methods have not transitioned to the midwave infrared (MWIR) primarily because other techniques have been sufficient and MWIR laser sources with sufficient output power have been unavailable. However, as the detector pitch decreases, MTF measurements become more difficult due to diffraction, while potential MTF degradation due to lateral carrier diffusion crosstalk makes accurate MTF characterization critical for sensor system design. Here, a random laser speckle FPA MTF measurement approach is adapted for use in the MWIR that utilizes a quantum cascade laser coupled with an integrating sphere to generate the appropriate in-band random speckle. Specific challenges associated with the technique are addressed including the validity of the Fresnel diffraction assumptions describing the propagation of the random speckle field from the integrating sphere to the FPA. Improved methods for estimating the power spectral density (PSD) of the measured speckle that reduce data requirements are presented. The statistics and uniformity of the laser speckle are presented along with PSD measurements and estimated MTFs of a MWIR FPA.

Coupling-of-modes analysis and modeling of polymer-coated surface acoustic wave resonators for chemical sensors

The analysis and modeling of SAW resonator devices based on the coupling-of-modes (COM) theory are described, integrating the effect of polymer coating so that the sensor effects can be accounted for in the device transfer function. Based on the perturbation method, the effects of film coating are included in determining the parameters for the model. The COM parameters are, therefore, modified and its simple analytical approaches are presented. The model is validated using the experimental data of a two-port SAW resonator device fabricated on ST-X quartz substrate. The experimental results for a device coated with Parylene C are compared with the simulation results of the proposed model. The comparative results of the electrical characteristics and the frequency sensitivity to film thickness show a good agreement which proves the validity of the model. This analysis and model will provide insight into the influence of the device design parameters on the sensor performance and help in practical design and optimization of SAW-based chemical sensor systems.

Preface of special issue: advanced topics on wireless sensor networks

SUMMARYThe recent advancement of wireless sensor networks (WSNs) technologies and practices is one of the major roles to the evolution and enrichment of human life with the advent of the next generation convergence network environments. A variety of usages and paradigms for WSNs is a growing interest in the design, development, and deployment of sensor systems for applications with other emerging technologies such as RFID Technology, Multimedia Based Surveillance System, Biomedical Technology, Mobile Agent based Networks, P2P technology and Business Process, and others. With rapid increases in applications, new architecture and techniques are required to support WSNs. Copyright © 2012 John Wiley & Sons, Ltd.

Design and construction of optical fiber sensor system for detection of stress and fine motion

Two main concepts in design and construction of stress and fine motion detection system using fiber optic sensor was included in this project. The first is design and construction concept using Intensity Modulation techniques using plastic multimode optical fiber (125μm dim) and has N A =0.27 with losses rate 2.1 db and directionality about 25 db, and we used He-Ne laser source (632.8 nm) with LLM-2 light power meter to detect the variation in output laser power due to micro-displacement for movement body under test. The second concept includes Modeling for laser beam tracking through fiber and that which reflected for mirror to detector. Variation in output power due to target movement was theoretical analyzed from study of variation of Gaussian front wave profile of using MATLAB program within displacement range from 0-5 mm. Non-linear relation between separated distance and beam intensity was investigated. Finally our design are evaluated in comparison with published research which is found compatible in theoretical and experimental results.

A Transformer Partial Discharge Measurement System Based on Fluorescent Fiber

Based on the physical phenomena of optical effects produced by the partial discharge (PD) and on the characteristics of fluorescent fiber sensing of weak fluorescent signals, a PD measurement system using a fluorescent fiber sensor was designed. The main parameters of the sensing system were calculated, an experimental testing platform for PD simulation in the lab was established, and PD signals were then detected through ultra-high frequency (UHF) and optical methods under a needle-plate discharge model. PD optical pulses in transformer oil contained signal-peak and multi-peak pulse waveforms. Compared with UHF detection results, the number of PD pulses and the elapsed PD pulse phase time revealed a good corresponding relationship. However, PD signal amplitudes presented the opposite, thus indicating that PD UHF signals reflected pulse amplitude value, whereas PD optical signals reflected pulse energy magnitude. The n-u-φ three-dimensional distributions indicated that most of the PD signals concentrated in the nearby industrial frequency voltage peak value. Overall, the proposed fluorescent fiber sensing system design can be used successfully in transformer PD signal detection.

Design of Monitoring and Sensor Systems for Bioprocesses by Biomechatronic Methodology

AbstractBiomechatronic design methodology is discussed for the design of monitoring and sensor systems for biotechnological processes. The bioprocess monitoring systems are examples of complex biomechatronic systems between electronic, mechanical, and biological subsystems, and where in particular the biological parts, through active microbial or cellular components, influence the design solutions in a complex manner. The biomechatronic approach facilitates configuration of the monitoring and sensor systems with production and quality needs in focus, and can by that lead to more efficient design solutions.

Design of an LED-based sensor system to distinguish human skin from workpieces in safety applications

Commercial light curtains use a technique known as muting to differentiate between work pieces and other objects (e.g., human limbs) based on precise model knowledge of the process. At manually fed machinery (e.g., bench saws), such precise models cannot be derived due to the way the machinery is used. This paper presents a multispectral scanning sensor to classify an object's surface material as a new approach for the problem. The system is meant to detect the presence of limbs and therefore optimized for human skin detection. Evaluation on a test set of skin and (wet) wood samples showed a sufficiently high reliability with respect to safety standards.

Optical Fiber Networks for Remote Fiber Optic Sensors

This paper presents an overview of optical fiber sensor networks for remote sensing. Firstly, the state of the art of remote fiber sensor systems has been considered. We have summarized the great evolution of these systems in recent years; this progress confirms that fiber-optic remote sensing is a promising technology with a wide field of practical applications. Afterwards, the most representative remote fiber-optic sensor systems are briefly explained, discussing their schemes, challenges, pros and cons. Finally, a synopsis of the main factors to take into consideration in the design of a remote sensor system is gathered.

Sensor systems for high-speed intelligent sorting of waste paper in recycling

Sorting paper into compatible grades is a necessary step before recycling. Current methods of man¬ually sorting are tedious, slow, and expensive. High-speed automation of the sorting process will improve the cost efficiency and increase the amount of paper recycled significantly. Correct identification of the sample in real-time before the sample reaches the actuation station still remains a challenge because different types of paper and board samples are mixed in a waste stream, and have a lot of variation in terms of color, chemical composition, coating, and printing in black and white and color to different degrees. This primarily is because of a lack of satisfactory sen¬sors and sensor fusion algorithms for sample identification in real-time. In this paper, we identify key parameters that must be measured, discuss a sensor system design, and describe integration of the output from sensors to interpret the type of sample using a fuzzy inference algorithm. Results show that the sensor system proposed is capable of identifying the samples at 90% accuracy compared to manual identification. The sensor system can be integrated onto a conveyor and actuation system for automated sorting.

The Design of the FBG Sensor System for Strain Monitoring Specific to the Key Stratum in Casing Annulus

Due to the tube is suffering deformation and damage by a series of factors, such as external force, chemical corrosion etc. The production of oil and the oil wells' service life is directly affected. As the number of casing damage is increasing year by year, the casing damage especially the casing inspection of key layer has become the focus of oilfield development process. The height of critical layer is usually about 5m, so the author puts forward that it's much more accurate to use the distributed FBG sensor as the short distance measurement method to guarantee the precision, and coupled with the traditional temperature compensation method of FBG strain monitoring. With a special installation process and the application of 40-Caliper logging tool to get the FBG' s azimuth, we get real-time strain data in the process of installing casing pipe. This paper analyzes the variation of value of the casing strain in each installation stage, the theoretical calculation results are basically the same with the data got by XMAC logging method. This proves the reliability of the distributed casing deformation monitoring system which is specifically used for the key layer of casing annulus.

System Theoretical Aspects for Designing Opto- Electronic Sensors for Remote Sensing

The design of passive optical sensor systems for remote sensing requires more or less complex theoretical investigations. Based on the user requirements which are characterized by data products all relevant physical effects influencing the generation of an image have to be considered and modeled. The goal is to build the whole chain of signal generation and transformation: from the source of light, through the atmosphere to the object to be observed, through the atmosphere again to the sensor system. These models can be applied for simulations which can be used for the optimization of sensor parameters and observation conditions and for the estimation of the potential performance of such a system. For this task, specific retrieval algorithms have to be considered closing the loop of developing camera systems. The paper contains classical approaches for a system design as a standard tool used in the Institute for Robotics and Mechatronics including methods for modeling the geometrical and radiometric relations and the description of camera hardware. The results of a complex investigation of the point spread function of camera systems is core topic of this paper.

Long-term microclimate monitoring in wildland cultural heritage sites with wireless sensor networks

Microclimates in many wildland cultural heritage sites are not under surveillance up to now, due to the lack of power supply and network access. However, real-time microclimate data in cultural heritage sites are very important for research and conservation. In this paper, we discuss the design of a wireless sensor system for long-term microclimate monitoring in wildland cultural heritage sites. Tiered and robust communication architecture including wireless sensor network (WSN), long-distance wireless polling network (LWPN) and internet was developed to realise stable monitoring in complex and harsh environment. Meanwhile, fault detection and diagnosis strategies have been designed to enable quick system restoration once a severe failure occurs. The currently deployed system consists of 241 data sensors covering 57 typical caves of the Mogao Grottoes. The stability and long lifetime of the system are verified through network and battery performance evaluations at the end of the paper.

Information Theoretic Metrics to Characterize Observations in Variational Data Assimilation

Data assimilation obtains improved estimates of the state of a physical system by combining imperfect model results with sparse and noisy observations of reality. Not all observations used in data assimilation are equally valuable. The ability to characterize the usefulness of different observation locations is important for analyzing the effectiveness of the assimilation system, for data pruning, and for the design of future sensor systems. This paper proposes a new approach to characterizes the usefulness of different observation in four dimensional variational (4D-Var) data assimilation. Metrics from information theory are used to quantify the contribution of observations to decreasing uncertainty with which the system state is known. We derive ensemble based, computationally feasible procedures to estimate the information content of various observations.