基于LoRa无线扩频通信的水情监测与预警系统

为解决目前水情监测系统中存在通信距离受限、功耗大、成本高、无法泛组网的问题,提出了一种基于LoRa(Long Range)扩频技术的水情监测与预警系统。通过采用新型的LoRa无线扩频技术,使用无线传感器网络自适应占空比协议优化网络性能与功耗,并结合当前流行的微控芯片、传感器与阿里云物联网(Internet of Things,IoT)平台,构建了一套覆盖范围广、低功耗、低成本、组网灵活简单、能远距离通信、抗干扰能力强的水情远程监测与预警系统。系统设计完成后,在长江水域重庆段对系统进行了测试,验证了系统设计的可行性、组网通信的有效性以及远距离传输数据的特性,为水文水情数据的自动化远程监测提供了一种新的技术方案。     

LoRa-Based WSNs Construction and Low-Power Data Collection Strategy for Wetland Environmental Monitoring

The wetland that known as "the kidney of the earth" is an ecological system with many resources. Monitoring of wetland environment includes the monitoring of water quality, air and soil. The parameters of temperature, pH value, turbidity, dissolved oxygen (DO), water level, conductivity of water, illuminance, PM2.5, harmful gas, and soil moisture is particularly important for the survival of animals in wetland. Real-time monitoring wetland environment is conducive to understanding the causes and trends of environmental change in the whole region, so as to make environmental change emergency strategies timely. The author introduces a real-time monitoring system based on Multi-sensor Combination Module (MSCM) and LoRa. This system has two types of MSCM, one is for water and the other is for air. The MSCM for water consists of six sensors, such as water temperature sensor, pH sensor, turbidity sensor, dissolved oxygen sensor, conductivity sensor, and water level sensor, and stm32 core processor, which has the advantages of low power consumption and high speed. The data collection node uploads the collected data to the base station through a LoRa module with low power consumption, high speed and wide coverage. The base station and the collection node are connected in a star. The LoRaWan protocol is used to realize the communication between acquisition nodes and sink. In the case of code rate is 4/5, bandwidth is 500 kHz and spreading factor is 12, the effective throughput of the system can reach 1172 bps. At the same time, a data fusion algorithm based on fuzzy decision is designed for data processing on the acquisition nodes to reduce the amount of uploaded data, reduce power consumption and improve network throughput. Experiments show that the system has strong stability, flexible networking, low power consumption, long communication distance, and is suitable for wetland environmental monitoring.

     

基于无线传感器网络的早期火灾图像探测系统

针对传统火灾监控系统存在的不足,设计了一种基于无线传感器网络的新型早期火灾图像探测系统.首先利用图像传感器实时采集现场图像,并通过低功耗的无线传感器网络将图像信息传送至ARM处理器中,再利用火灾图像识别算法对获取的图像进行分析处理,从而判断是否发生火灾,最后采用GPRS和Internet方式实现远程监控.该火灾图像探测系统能够进行早期火灾的检测与报警,具有较高的技术先进性和良好的应用前景.     

低功耗电阻型MEMS半导体气体传感器研究进展北大核心

电阻型MEMS半导体气体传感器在环境空气质量监测和有毒有害气体检测等领域得到了广泛应用，但是受限于功耗较高的原因，这类传感器难以广泛应用于便携式气体检测系统。文章综述了近年来低功耗电阻型MEMS半导体气体传感器的研究进展，分别从气敏材料、传感器结构和传感器模组的集成电路等方面探讨如何实现低功耗的电阻型MEMS半导体气体传感器的制备，并展望低功耗的电阻型MEMS半导体气体传感器未来的发展方向。     

基于云计算的矿井无线传感网络火情远程监控系统

针对矿井实际需求情况,提出了一种基于云计算的无线传感网络火情远程监控系统,此系统包括通讯基站、无线传感器网络和云计算平台,其中,无线传感器网络通过通讯基站与云计算平台相连接。它包括用于采集煤矿安全数据的无线传感器、执行器和用于传输煤矿安全数据的无线网关。该系统具备低成本、自组织、低功耗、信息交互方便的特点,具有很好的应用前景。     

低功耗水下探测器设计

水下探测器是海洋环境监测的重要设备,为解决传统水下无人探测器续航能力弱等问题,设计了一种新型的低功耗水下探测器。其采用新型集成式传感器,降低了传感器电路的功耗;具备多功能扩展接口,可搭载其它传感器或推进装置;搭载的能量采集模块用来获取探测器周边环境能量,可提高探测器的续航能力;主控电路采用了低功耗设计,可对不同传感器及功能模块进行单独控制,精准调控电路系统的功耗,优化供电逻辑,大大提高探测器的集成度和续航能力。     

A Self-Powered,Rechargeable, and Wearable Hydrogel Patch for Wireless Gas Detection with Extraordinary Performance

Flexible gas sensors play an indispensable role in diverse applications spanning from environmental monitoring to portable medical electronics. Full wearable gas monitoring system requires the collaborative support of high-performance sensors and miniaturized circuit module, whereas the realization of low power consumption and sustainable measurement is challenging. Here, a self-powered and reusable all-in-one NO₂ sensor is proposed by structurally and functionally coupling the sensor to the battery, with ultrahigh sensitivity (1.92%/ppb), linearity (R² = 0.999), ultralow theoretical detection limit (0.1 ppb), and humidity immunity. This can be attributed to the regulation of the gas reaction route at the molecular level. The addition of amphiphilic zinc trifluoromethanesulfonate (Zn(OTf)₂) enables the H₂O-poor inner Helmholtz layer to be constructed at the electrode–gel interface, thereby facilitating the direct charge transfer process of NO₂ here. The device is then combined with a well-designed miniaturized low-power circuit module with signal conditioning, processing and wireless transmission functions, which can be used as wearable electronics to realize early and remote warning of gas leakage. This study demonstrates a promising way to design a self-powered, sustainable, and flexible gas sensor with high performance and its corresponding wireless sensing system, providing new insight into the all-in-one system of gas detection.     

Application of the thermoelectric MEMS microwave power sensor in a powerradiation monitoring system

A power radiation monitoring system based on thermoelectric MEMS microwave power sensors is studied. This monitoring system consists of three modules: a data acquisition module, a data processing and display module, and a data sharing module. It can detect the power radiation in the environment and the date information can be processed and shared. The measured results show that the thermoelectric MEMS microwave power sensor and the power radiation monitoring system both have a relatively good linearity. The sensitivity of the thermoelectric MEMS microwave power sensor is about 0.101 mV/mW, and the sensitivity of the monitoring system is about 0.038 V/mW. The voltage gain of the monitoring system is about 380 times, which is relatively consistent with the theoretical value. In addition, the low-frequency and low-power module in the monitoring system is adopted in order to reduce the electromagnetic pollution and the power consumption, and this work will extend the application of the thermoelectric MEMS microwave power sensor in more areas.     

Ingestible capsule for impedance and pH monitoring in the esophagus

Twenty-four-hour ambulatory pH monitoring is an essential tool for diagnosing gastroesophageal reflux disease (GERD). Simultaneous impedance and pH monitoring of the esophagus improves the detection and characterization of GERD. Conventional catheter-based monitoring systems are uncomfortable and interfere with the normal activity of the patient. To overcome these disadvantages, different wireless esophageal monitoring systems have been proposed. A capsule containing sensors for impedance and pH monitoring with wireless communication capabilities is presented. A low cost miniature microcontroller was utilized for interfacing between the sensors and a wireless transmitter. The microcontroller program allowed efficient management of the electric power provided by a 3-V battery. Magnetic holding is proposed as an alternative to surgical affixation of the monitoring capsule. Permanent neodymium magnets separated by 27 cm successfully held the capsule in a test tube. Experimental results demonstrated that friction force can aid magnetic holding to overcome peristalsis. The proposed design efficiently detected acid and nonacid reflux. More research regarding the holding method and capsule packaging are necessary to optimize the mechanical performance of the proposed design in order to facilitate clinical testing on human subjects.     

水质自动监测控制系统

水质自动监测控制系统是一套含水质自动分析仪、数据采集、站点控制、远程监控、数据发布于一体的在线全自动监控系统。该系统实现了对水质的实时连续监测和远程控制,能及时发现主要流域水质的异常变化,追踪污染源,对水质污染迅速做出预警预报,从而有效避免水质污染事故的扩大。     

A low power wireless node for contact and contactless heart monitoring

Ubiquitous vital signs sensing and processing are promising alternatives to conventional clinical and ambulatory healthcare. Novel sensors, low power solutions for processing and wireless connectivity are creating new opportunities for wearable devices which allow continuous and long term monitoring, while maintaining freedom of movement for the users. This paper presents a low-power embedded platform with novel high sensitivity electric potential dry surface sensors that can be used in either contact or non-contact mode to measure biomedical signals. The proposed low power system is optimized to compute the heart rate and respiratory rate close to the sensors. This approach reduces the amount of data that needs to be transmitted to a host device. It allows also the platform to be autonomous and wearable or even be used in cars for applications such as driver drowsiness detection. Experimental measurements show the acquisition and the processing of data from sensors and the low power consumption achieved with the node in different modes of operation.     

A survey on sensor placement for contamination detection in water distribution systems

Frequent water pollution incidents have occurred recently, leading to severe damages, economic loss, and long-lasting society impact. Therefore, installation of water quality monitoring sensors in water distribution system (WDS) has been advocated as a viable solution to enable real-time pollution detection and thus the mitigation of the risks associated with catastrophic contamination incidents. Given the significant cost of placing sensors at all locations in a network, a critical issue is where to deploy the sensors within the distribution system while the network still gets covered. Although there exist a significant number of articles on sensor placement, WDS for contamination detection is unique comparing to other networks such as power grids, road networks, structural networks and microwave radio networks. In this paper, we conduct a comprehensive literature survey on the sensor placement problem for contamination detection in WDS, with a special focus on optimization strategies and framework. Current challenges, issues, and research directions are also identified and discussed.

     

基于Zigbee技术的室内安防报警系统的设计和实现

文章提出并实现了一种基于Zigbee技术的室内安防报警系统。系统采用单片机CC2530进行前端数据（如温度、烟雾等信息）的采集和检测,并利用红外探测器、玻璃破碎探测器等传感器对非法入侵进行检测,构建了一套数据采集平台。通过Zigbee协议搭建的无线通信网络,将各传感器和前端检测器的数据采集信息发送到远端基站,基站接收的数据通过串口通信发送给上位机,上位机进行数据分析和处理。系统不仅能实现多重数据的实时监测,同时还可对异常情况进行报警。实验证明,本系统结构简易可行、功耗低,且性能稳定,在室内安防报警领域有较好的应用前景。     

CMOS sensors for on-line thermal monitoring of VLSI circuits

The paper presents appropriate sensors for the realization of the design principle of design for thermal testability (DfTT). After a short overview of the available CMOS temperature sensors, a new family of temperature sensors will be presented, developed by the authors especially for the purpose of thermal monitoring of VLSI chips. These sensors are characterized by the very low silicon area of about 0.003-0.02 mm² and the low power consumption (200 μW). The accuracy is in the order of 1°C. Using the frequency-output versions an easy interfacing of digital test circuitry is assured. They can be very easily incorporated into the usual test circuitry, via the boundary-scan architecture. The paper presents measured results obtained by the experimental circuits. The facilities provided by the sensor connected to the boundary-scan test circuitry are also demonstrated experimentally     

Big Data Knowledge Discovery as a Service: Recent Trends and Challenges

In remote area industrial systems, energy consumption monitoring is a crucial challenge. As the conventional monitoring methods lack an intelligent approach, the finest energy consumption monitoring is not possible. Hence, Internet of Things (IoT) based monitoring methods have been developed by recent industrial systems. Therefore, in this research, a novel cloud with IoT based energy monitoring technique is developed. The energy parameters of the Computer Numerical Control based milling machine has been gathered using IoT based Current Transducers , Voltage Transducers , and power sensors. The IoT device includes Zigbee or Bluetooth for managing communication between the machine and the monitoring system. Then the obtained data is stored in the cloud storage platform for large scale machine energy data in the windows platform. Later on, the obtained data from cloud storage is processed by the novel Normalized Recursive Least Kalman Filter for event detection processing. Moreover, the feature extraction has been done using the proposed Simplified Principal Component Analysis method. Furthermore, the energy utilization of the machine is monitored over various situations using the proposed novel Dynamic Self-evolving Reasoning based Fuzzy Neural algorithm. The Median Absolute Deviation is estimated for the conditional inference of the system. The software implementation of this work is done in MATLAB. The power consumption of the machine is validated under various cases. Besides, the proposed simulation outcomes are compared with various existing energy monitoring systems for verifying the significance of the developed method.

     

A telemetry-instrumentation system for monitoring multiplesubcutaneously implanted glucose sensors

An implantable potentiostat-radiotelemetry system for in vivo sensing of glucose is described. An enzyme electrode sensor measures the oxidation current of hydrogen peroxide formed by the stoichiometric conversion of glucose substrate and oxygen cofactor in an immobilized glucose oxidase layer. The sensor current is converted to a frequency and transmitted at programmable intervals (4, 32, 256 s) to a remote receiver. Low power CMOS circuitry is employed and device operation for up to 1.5 years is predicted using two series connected 250 mAh lithium cells. Crystal controlled RF frequencies uniquely identify each sensor allowing over 10 sensors within the same 10 m radius. A custom interface card allows a PC to program the receiver and handle the transmitted sensor data using software written in Microsoft C and QuickBasic. Software control allows on-the-fly sensor addition or subtraction to the sensor group being monitored. Over 10 sensors can be tracked long-term using the longest transmit interval, or four sensors can be tracked during short-term infusion studies when the transmit interval is reduced to 4 s. The design, construction, operation, and performance of the system hardware and software are described and evaluated     

Design of integrated and autonomous conductivity–temperature–depth (CTD) sensors

Impedance characterization of interfaces is a basic technique for a large class of chemical and biological sensors. This technique is often used to model interfaces between ion-based and electron-based conductive materials by means of electric variables such as voltage, current and charge. Conductivity–temperature–depth (CTD) sensors are sophisticated devices used in the environmental monitoring field to understand the effects of climate changes on oceans and on marine organisms. They usually require impedance sensing as readout technique. High-accuracy CTD sensors are present on the market but they are bulky and power hungry. However, the downscale of modern CMOS technology allows shrinking very complex bioelectronic interfaces into millimeter square size systems, thus opening a large ground of applications. This paper will describe an IC architecture and the related design approach to implement an electrochemical impedance spectroscopy (EIS) technique for CTD sensing and will propose a general approach for sensing complex impedance with low power consumption and high precision. The presented system is designed to achieve 15-bit resolution and power consumption to ensure lifetime up to 1 year using button-size batteries in ocean environment.     

基于ARM和FPGA的远程温度测控系统

为满足航天仪器在飞行试验过程中对环境温度变化的测控,提出了一种基于ARM和FPGA的远程温度测控系统,以STM32F103和XC2S200作为控制核心,通过高精度AD采集芯片ADS1148采集温度传感器端的电压信号,通过ADS1148内部放大、转换成数字量信号,再通过SPI接口传输给控制核心STM32F103。为了实现远端控制,能在2.5 km对-160℃~1370℃温度范围的测控,设计了光电转换模块,把采集的数字量信号转换成光信号传输给近端的控制台,实现温度的远程、实时监测。该项目已经在某航天仪器上的应用实践表明,该系统测温范围广、精度高、功耗低、可靠性高。     

单片机电力监控系统交流采样的实现及抗干扰措施

以８０９８单片机为主体设计远程电力监控系统的用户级分站，能做到低成本、高性能，适用于监控中小型电力用户的用电情况．电力参数的数据采集是其从重要的环节，要求硬件投资少，软件占用ＣＰＵ时间少．本文介绍了用８０９８单片机实现电力参数交流直接采样技术的一套经济实用而又稳定可靠的方法，对其硬件结构原理、软件设计思想以及去除现场干扰的软硬件措施等进行了阐述．     

基于ARM7的远程视频监控系统

利用ARM7芯片LPC2478实现了低功耗远程实时视频监控系统。该系统主要针对电力线的监控,提高电力线的安全性。主要从硬件方面叙述系统各部分的组成及实现方式,该系统的硬件部分以LPC2478为MCU（微控制器）,还包括电源、视频采集／编码、气象传感器及无线通信等部分。该系统的监控中心通过无线网络控制下位机对现场视频及气象数据进行采集,再对数据进行相应处理,然后将数据发送到监控中心。本系统已经在实际中应用,系统运行良好。