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Design of a Grating Lobes-Free Architecture for distributed sensor system with Arbitrary Element Spacing

REMOTE SENSING 2022年第6期14卷 1356-1356页

作者： Huang, Jiyan Liu, Chaoyang Hu, Wei Liao, Kuo Univ Elect Sci & Technol China Sch Informat & Commun Engn Chengdu 611731 Peoples R China State Key Lab Complex Electromagnet Environm Effe Changsha 410000 Peoples R China

Two main difficulties for the accurate direction of arrival (DOA) estimation in a distributed sensor system are grating lobes and system synchronization. Different from the traditional phased array system based on single carrier frequency, this paper designs a novel architecture for distributed sensor system using dual carrier frequency measurements. Both two carrier frequencies are combined and transmitted simultaneously in the proposed architecture. Instead of single carrier frequency f(1) in the traditional method, the frequency separation f(2) - f(1) is used in the proposed algorithm to determine a maximum unambiguous DOA estimate. Since f(2) - f(1) is much less than f(1) and the choice of f(2) - f(1) is more flexible, the proposed method can provide an unambiguous DOA estimate in the whole field of view (FOV) for arbitrary element spacing and a looser requirement on system synchronization than the traditional method based on single carrier frequency. For a case with f(1) = 3 Ghz, f(2) - f(1) = 150 Mhz and 10 times element spacing, there is no grating lobe for the proposed method in the whole FOV [-pi/2, pi/2], whereas the traditional method has many grating lobes and the FOV of the traditional method without grating lobes is only 5.73 degrees. To obtain the same combining efficiency in this case, the requirement on the positioning error of the proposed method is 0.4 m and the location error of the traditional method must be smaller than 0.02 m. Hence, the proposed method can greatly reduce hardware requirements. The performances of the proposed architecture for the cases with perfect and imperfect system synchronizations are evaluated in terms of the average beampattern and combining efficiency, respectively. Some characteristics of the derived beampattern and combining efficiency are also presented in the paper.

关键词： distributed sensor system beampattern grating lobes beamforming combining efficiency dual frequencies

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Evaluating the Joint Use of LoRaWAN and Bluetooth Mesh to Improve Survivability for Critical sensor Applications

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IEEE sensorS JOURNAL 2024年第14期24卷 22992-23003页

作者： Sisinni, Emiliano Depari, Alessandro Flammini, Alessandra Rinaldi, Stefano Ferrari, Paolo Univ Brescia Dept Informat Engn I-25123 Brescia Italy

Wide area, wireless, Internet of Things (IoT)-based, distributed sensor systems can be employed in mixed criticality solutions for measurement/detection/signaling of emergencies, dangers, accidents, and disasters. All these scenarios require reliability, security, and safety. This work introduces and characterizes a new proposal to enhance existing LoRaWAN applications by adding a transparent redundant channel just for critical traffic. Network survivability and delivery success of critical messages, even with low LoRaWAN signal quality (as in indoors), is increased. The proposal preserves the LoRaWAN backend structure (including end-to-end (E2E) security) using short-range radios to implement an underlying redundant mesh channel for transparently transporting LoRaWAN traffic of critical applications. Hybrid scenarios with legacy standard nodes coexisting are also permitted. The proof-of-concept combines LoRaWAN and, without losing generality, a redundant channel with Bluetooth mesh (BM). This work includes: metrics definition, evaluation of complex scenario by means of simulations, and real experiments demonstrating feasibility and integration with LoRaWAN-compliant backend using commercial hardware/firmware/software. In particular, results confirm that packet loss in the order of 1% on the BM side can be obtained and therefore the critical traffic delivery success is improved by almost two orders of magnitude.

关键词： Wireless sensor networks Wireless communication Communication system security Topology Bluetooth Uplink Security distributed sensor system low power area network (LPWAN) mesh network mixed criticality multi-interface protocol encapsulation

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Ultra-Low-Power Smart Electronic Nose system Based on Three-Dimensional Tin Oxide Nanotube Arrays

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ACS NANO 2018年第6期12卷 6079-6088页

作者： Chen, Jiaqi Chen, Zhuo Boussaid, Farid Zhang, Daquan Pan, Xiaofang Zhao, Huijuan Bermak, Amine Tsui, Chi-Ying Wang, Xinran Fan, Zhiyong Hong Kong Univ Sci & Technol Dept Elect & Comp Engn Kowloon Hong Kong Peoples R China Univ Western Australia Dept Elect Elect & Comp Engn Perth WA 6009 Australia Nanjing Univ Sch Elect Sci & Engn Natl Lab Solid State Microstruct Nanjing 210093 Jiangsu Peoples R China Nanjing Univ Collaborate Innovat Ctr Adv Microstruct Nanjing 210093 Jiangsu Peoples R China Hamad Bin Khalifa Univ Coll Sci & Engn Doha Qatar

In this work, we present a high-performance smart electronic nose (E-nose) system consisting of a multiplexed tin oxide (SnO2) nanotube sensor array, read-out circuit, wireless data transmission unit, mobile phone receiver, and data processing application (App). Using the designed nanotube sensor device structure in conjunction with multiple electrode materials, high-sensitivity gas detection and discrimination have been achieved at room temperature, enabling a 1000 times reduction of the sensor's power consumption as compared to a conventional device using thin film SnO2. The experimental results demonstrate that the developed E-nose can identify indoor target gases using a simple vector-matching gas recognition algorithm. In addition, the fabricated E-nose has achieved state-of-the-art sensitivity for H-2 and benzene detection at room temperature with metal oxide sensors. Such a smart E-nose system can address the imperative needs for distributed environmental monitoring in smart homes, smart buildings, and smart cities.

关键词： tin oxide nanotube low-power gas sensor gas recognition electronic nose distributed sensor system

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MIMO radar techniques: two-stage constant false alarm rate detection for fast-fluctuating targets

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JOURNAL OF ENGINEERING-JOE 2019年第20期2019卷 6664-6667页

作者： Li, Zhihua Su, Hongtao Hu, Qinzhen Zhou, Shenghua Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Shaanxi Peoples R China

Here, the authors analyse a two-step constant false alarm rate (CFAR) detection problem in distributed sensor system (e.g. statistical multiple-input multiple-output (MIMO) radar) for fast-fluctuating targets (TS-AMF-II). The scheme arises when a data rate restriction forces each of the distributed systems to censor their detection statistics before sharing and is motivated by the fact that the clutter plus noise power and the signal to clutter plus noise ratio may be both unknown in practice. The proposed detector has two thresholds: the first one called local threshold controls the communication rate and the second one called global threshold adjusts the global probability of false alarm. Numerical results illustrate that the proposed detector has good detection performance at a low communication rate.

关键词： radar detection MIMO radar statistical analysis radar signal processing distributed sensors probability object detection radar clutter MIMO communication low communication rate clutter plus noise ratio clutter plus noise power detection statistics distributed systems data rate restriction forces TS-AMF-II distributed sensor system two-step constant false alarm rate detection problem fast-fluctuating targets two-stage constant false alarm rate detection MIMO radar techniques

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Problems and Solutions for Refitting a sensor Network with IEEE1588 Clock Synchronisation 19

Problems and Solutions for Refitting a Sensor Network with I...

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19th IEEE International Conference on Emerging Technology and Factory Automation (ETFA)

作者： Puhm, Andreas Kramer, Michael Moosbrugger, Patrick Horauer, Martin Univ Appl Sci Technikum Wien A-1200 Vienna Austria

ISBN: (纸本)9781479948451

Nowadays, multiple sensor nodes are often incorporated into technical solutions forming distributed sensor systems. Herein, advanced detection mechanisms are often realised by using data from multiple sensors in such a network. However, sometimes active sensors - like Time-Of-Flight cameras - interfere with each other. To solve this problem and assist in data correlation, a clock synchronisation method, like IEEE1588, can be adapted. Although, if the sensor nodes have not been developed with this in mind they have to be refitted. An optimal refit of a system is the one that needs the least modifications necessary to achieve the desired goal. This paper lists the impact - in terms of jitter and asymmetry - that different components of a system have on IEEE1588 synchronisation precision and methods to eliminate or alleviate jitter and asymmetry sources in order to enable respective sensor fusion.

关键词： IEEE standards distributed sensors jitter sensor fusion synchronisation IEEE1588 clock synchronisation active sensor data correlation distributed sensor system multiple sensor node sensor network refitting Delays Hardware IP networks Jitter Software Switches Synchronization

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distributed sensor system and its application

Distributed sensor system and its application

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37th SICE Annual Conference (SICE98)

作者： Pang, YB Wei, XY Wu, YH Beijing Univ Chem Technol Beijing Peoples R China

ISBN: (纸本)0780350537

This paper presents a concept of distributed sensor system (DDS). The structure and functions of DSS are given. Based on the sensor network, DSS may realize the detection of complex information with the cooperation of each sensor in the system. DSS can synthesize the signal processing technique, sensor data fusion methods and artificial intelligence technique etc. to solve the difficult sensing problems. Unlike a common sensor, the output of DSS will be a set of information including some inferable results. The information society would need more and more DSS in the future.

关键词： distributed sensors sensor fusion computer networks artificial intelligence knowledge based systems distributed sensor system sensor network signal processing sensor data fusion methods artificial intelligence technique AI

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distributed chemical sensing

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sensorS AND ACTUATORS B-CHEMICAL 1997年第1期45卷 71-77页

作者： Eklov, T Sundgren, H Lundstrom, I Linkoping Univ Appl Phys Lab S-58251 Linkoping Sweden Linkoping Univ S SENCE S-58251 Linkoping Sweden

When a gas mixture is passed over a catalytic surface its composition will change due to the catalytic activity of the surface. Different molecules have different reaction rates and this fact can be used in combination with distributed chemical sensors to increase the discriminating capability of the sensors. in a measurement cell (palladium covered or non-covered) a row of identical Pd-MOSFET sensors was mounted along the flow direction. The catalytically active measurement cell changed the concentration of detected molecules (hydrogen or ethanol) considerably compared to the non-catalytic cell. It was observed that even catalytic combustion in the lid 1 mm above the sensor row influenced the sensor responses significantly. When comparing hydrogen and ethanol it was found that the two molecules were influenced to different degrees when passing the catalytic surfaces. Hydrogen was consumed at a much faster rate, which could tie seen when comparing the sensor responses along the row. A distributed sensor system thus shows an increased discriminating power. It was also found that chemical sensing was much more temperature dependent for ethanol than for hydrogen. (C) 1997 Elsevier Science S.A.

关键词： Pd-MOSFET gas sensor distributed sensor system catalytic surface selectivity

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Self diagnosis and self calibration strategies for distributed intelligent sensor systems

Self diagnosis and self calibration strategies for distribut...

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Conference on Smart Sensing, Processing, and Instrumentation - Smart Structures and Materials 1997

作者： Rezeki, SMS Xu, YP Haskard, MR Davey, DE Univ. of South Australia (Australia)

ISBN: (纸本)0819424552

This paper describes a self-diagnosis and self-calibration technique to be employed in a distributed intelligent sensor system for environmental monitoring. With this 'built-in intelligence' the system is expected to be low in maintenance and advises the central computer whenever the sensor is faulty and needs to be replaced. A majority voting scheme is proposed to detect the hard-errors while the sensor output signal features are analysed to detect the soft-errors. Flow Injection Analysis is chosen as the sampling methodology. The overall flow chart of the system operation is also described.

关键词： distributed sensor system self-diagnosis self-calibration hard-error soft-error

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On the influence of coordinate transform upon measurement error of distributed system

On the influence of coordinate transform upon measurement er...

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1997 IEEE National Radar Conference

作者： Cheng, HW Sun, ZK Department of Electronic Technique National University of Defense Technology Changsha Hunan China

ISBN: (纸本)0780337328

Coordinate transformation is always concerned in data processing of distributed spasms. The influence of coordinate transformation upon measurement errors of the distributed sensor system is discussed in the paper. Detail derivations of tile relation equation between the original coordinate system anti the transformed new one, quantitative analysis of the influence and a number of fine curves are also given in the paper.

关键词： measurement errors radar signal processing transforms electronic countermeasures satellite navigation coordinate transform measurement error distributed system data processing distributed sensor system relation equation coordinate system quantitative analysis fine curves ECCM radar satellite location electronic counter counter measures

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