Recently, Wireless Sensor Network (WSN) has been widely applied in many fields. In this paper, we design and implement a WSN-based Electronic Intelligent Tag System (EITS) to provide intelligent management of the mode...Recently, Wireless Sensor Network (WSN) has been widely applied in many fields. In this paper, we design and implement a WSN-based Electronic Intelligent Tag System (EITS) to provide intelligent management of the modern supermarkets. As a main transceiver, nRF24L01+ wireless module is used in this system, which will make it possible to achieve low-power and low-cost for EITS. This system fully embodies the advantages and characteristics of WSN. This paper will introduce the system architecture, hardware structure and software design in details;and put forward a specific solution. Finally, we achieve the intelligent management of the mall based on wireless sensor network technology.展开更多
A wireless passive sensor array based on inductive-capacitive (LC) resonant circuits capable of simultaneously tracking two points of force loading is described. The sensor consisted of a planar spiral inductor connec...A wireless passive sensor array based on inductive-capacitive (LC) resonant circuits capable of simultaneously tracking two points of force loading is described. The sensor consisted of a planar spiral inductor connected to two capacitors forming a resonant circuit with two resonant frequencies. When a load was applied to one or both of the parallel plate capacitors, the distance between the plates of the capacitor was altered, thus shifting the observed resonant peaks. Testing illustrated that applied loading to a particular capacitor caused a significant shift in one of the resonant peaks and also a smaller shift in another resonant peak. This interdependence resulted from each capacitive element being connected to the same inductive spiral and was accounted for with a developed analysis algorithm. To validate the experimental observation, a circuit simulation was also generated to model the sensor behavior with changing force/displacement. The novelty of this system lies not only in its wireless passive nature, but also in the fact that a single LC sensor was fashioned to detect more than one point simultaneously.展开更多
To know the location of nodes is very important and valuable for wireless sensor networks (WSN), we present an improved positioning model (3D-PMWSN) to locate the nodes in WSN. In this model, grid in space is presente...To know the location of nodes is very important and valuable for wireless sensor networks (WSN), we present an improved positioning model (3D-PMWSN) to locate the nodes in WSN. In this model, grid in space is presented. When one tag is detected by a certain reader whose position is known, the tag’s position can be known through certain algorithm. The error estimation is given. Emulation shows that the positioning speed is relatively fast and positioning precision is relatively high.展开更多
氨气是畜禽场景中的主要有害气体之一,针对有源传感器不适于电路有线连接受限的畜禽场景问题,该研究基于高频电磁仿真软件(high frequency structure simulator,HFSS)设计了无源传感器仿真模型,选择聚酰亚胺(polyimide,PI)作为基板材料...氨气是畜禽场景中的主要有害气体之一,针对有源传感器不适于电路有线连接受限的畜禽场景问题,该研究基于高频电磁仿真软件(high frequency structure simulator,HFSS)设计了无源传感器仿真模型,选择聚酰亚胺(polyimide,PI)作为基板材料,采用丝网印刷技术研制了基于射频识别(radio frequency identification,RFID)原理的无源氨气传感标签。通过对氨气无源检测原理的解析,选择了具有高表面积的碳纳米管作为氨气敏感材料,推导了通过测量射频接收功率变化实现无源检测的数学模型;考虑谐振频率的动态调整,无源RFID传感标签采用开口间隙可调的裂环谐振器结构,通过分析传输系数的变化对RFID传感标签的检测过程进行模拟;搭建了用于实验室和畜禽场景氨气检测的射频测试系统,围绕功率反射系数、谐振频率、传输系数开展测试分析。试验结果表明,该标签检测效率易受到到二氧化碳、温湿度因素的影响,由于人工切割、基板变形、环境干扰等因素,实物标签的谐振频率与2.4 GHz的仿真谐振频率之间存在0.05 GHz左右的偏差,传感标签的灵敏度约为15 MHz·L/mg,最大阅读距离为24 cm,相比于商用氨气传感器,该传感标签在使用寿命、响应时间方面有明显优势。研究结果为畜禽场景的氨气无源检测提供了有效的理论和实践依据。展开更多
文摘Recently, Wireless Sensor Network (WSN) has been widely applied in many fields. In this paper, we design and implement a WSN-based Electronic Intelligent Tag System (EITS) to provide intelligent management of the modern supermarkets. As a main transceiver, nRF24L01+ wireless module is used in this system, which will make it possible to achieve low-power and low-cost for EITS. This system fully embodies the advantages and characteristics of WSN. This paper will introduce the system architecture, hardware structure and software design in details;and put forward a specific solution. Finally, we achieve the intelligent management of the mall based on wireless sensor network technology.
文摘A wireless passive sensor array based on inductive-capacitive (LC) resonant circuits capable of simultaneously tracking two points of force loading is described. The sensor consisted of a planar spiral inductor connected to two capacitors forming a resonant circuit with two resonant frequencies. When a load was applied to one or both of the parallel plate capacitors, the distance between the plates of the capacitor was altered, thus shifting the observed resonant peaks. Testing illustrated that applied loading to a particular capacitor caused a significant shift in one of the resonant peaks and also a smaller shift in another resonant peak. This interdependence resulted from each capacitive element being connected to the same inductive spiral and was accounted for with a developed analysis algorithm. To validate the experimental observation, a circuit simulation was also generated to model the sensor behavior with changing force/displacement. The novelty of this system lies not only in its wireless passive nature, but also in the fact that a single LC sensor was fashioned to detect more than one point simultaneously.
文摘To know the location of nodes is very important and valuable for wireless sensor networks (WSN), we present an improved positioning model (3D-PMWSN) to locate the nodes in WSN. In this model, grid in space is presented. When one tag is detected by a certain reader whose position is known, the tag’s position can be known through certain algorithm. The error estimation is given. Emulation shows that the positioning speed is relatively fast and positioning precision is relatively high.
文摘氨气是畜禽场景中的主要有害气体之一,针对有源传感器不适于电路有线连接受限的畜禽场景问题,该研究基于高频电磁仿真软件(high frequency structure simulator,HFSS)设计了无源传感器仿真模型,选择聚酰亚胺(polyimide,PI)作为基板材料,采用丝网印刷技术研制了基于射频识别(radio frequency identification,RFID)原理的无源氨气传感标签。通过对氨气无源检测原理的解析,选择了具有高表面积的碳纳米管作为氨气敏感材料,推导了通过测量射频接收功率变化实现无源检测的数学模型;考虑谐振频率的动态调整,无源RFID传感标签采用开口间隙可调的裂环谐振器结构,通过分析传输系数的变化对RFID传感标签的检测过程进行模拟;搭建了用于实验室和畜禽场景氨气检测的射频测试系统,围绕功率反射系数、谐振频率、传输系数开展测试分析。试验结果表明,该标签检测效率易受到到二氧化碳、温湿度因素的影响,由于人工切割、基板变形、环境干扰等因素,实物标签的谐振频率与2.4 GHz的仿真谐振频率之间存在0.05 GHz左右的偏差,传感标签的灵敏度约为15 MHz·L/mg,最大阅读距离为24 cm,相比于商用氨气传感器,该传感标签在使用寿命、响应时间方面有明显优势。研究结果为畜禽场景的氨气无源检测提供了有效的理论和实践依据。
