This paper presents a distributed wireless sensor network for multiple mobile agents localization. Localization of mobile agents, such as mobile robots, humans, and moving objects, in an indoor space is essential for ...This paper presents a distributed wireless sensor network for multiple mobile agents localization. Localization of mobile agents, such as mobile robots, humans, and moving objects, in an indoor space is essential for robot-robot interaction (RRI) and human-robot interaction (HRI). The standard localization system, which is based on sensors installed in the robot body, is not suitable for multiple agents. Therefore, the concept of sensor network, which uses wireless sensors distributed in a specified space, is used in this study. By analyzing related studies, two solutions are proposed for the localization of mobile agents including humans: a new hardware system and a new software algorithm. The first solution focuses on the architectural design of the wireless sensor network for multiple agent localization. A passive RFID system is used, and then the architecture of the sensor network is adapted to suit the target system. The second solution centers on a localization algorithm based on the sensor network. The proposed localization algorithm improves the accuracy in the multiple agent localization system. The algorithm uses the displacement conditions of the mobile agents and the recognition changes between the RFID tags and RFID reader. Through experiments using a real platform, the usefulness of the proposed system is verified.展开更多
研究设计并实现了一种基于U型谐振单元的无芯片射频识别(radio frequency identification,RFID)技术湿度传感器,该传感器结合Vivaldi宽频段天线,构建了一套无线无源的湿度传感系统,可实现对环境湿度的实时监测。无芯片RFID湿度传感器由8...研究设计并实现了一种基于U型谐振单元的无芯片射频识别(radio frequency identification,RFID)技术湿度传感器,该传感器结合Vivaldi宽频段天线,构建了一套无线无源的湿度传感系统,可实现对环境湿度的实时监测。无芯片RFID湿度传感器由8个U型谐振单元和1条与之耦合的微带线构成。在该设计中,两侧对称的谐振单元用于校准环境温度对湿度传感器的影响,其中1个单元由聚乙烯醇(polyvinyl alcohol,PVA)湿敏材料覆盖;中间6个U型单元用于RFID湿度传感器的ID信息编码。此外,本工作采用矩形环开槽技术优化了宽频带Vivaldi天线,并结合传感器实现了无线无源湿度传感。有线实验数据显示,在57%RH~71%RH的相对湿度范围内,产生了118 MHz的频率偏移,平均灵敏度为8.4 MHz/%RH。无线实验结果显示,在49%RH~70%RH的相对湿度范围内,产生了103 MHz的频率偏移,平均灵敏度为4.9 MHz/%RH。实验结果表明该无线无源湿度传感装置具有较高的检测灵敏度,可为无线无源湿度检测提供重要的解决方案。展开更多
生鲜农产品易发生品质劣变,其中氨气是反映其品质变化的重要检测指标。针对传统有芯片氨气传感器电路设计复杂、寿命有限问题,设计了一种无芯片射频识别(Radio frequency identification,RFID)氨气传感器,用于生鲜农产品挥发性氨气检测...生鲜农产品易发生品质劣变,其中氨气是反映其品质变化的重要检测指标。针对传统有芯片氨气传感器电路设计复杂、寿命有限问题,设计了一种无芯片射频识别(Radio frequency identification,RFID)氨气传感器,用于生鲜农产品挥发性氨气检测。首先,基于高频电磁仿真软件(High frequency structure simulator,HFSS)设计了微带贴片天线结构,研究了传感器天线的电磁场分布、回波损耗S11和极化特性,通过在微带天线上加载金属短路和寄生单元优化了传感器结构;采用激光雕刻技术制备传感器标签,并选择了在室温下对氨气具有良好选择性的ZnO/TiO_(2)纳米复合材料,将其喷涂在微带天线表面辐射单元上;其次,结合氨气射频检测原理,搭建了基于无芯片RFID的生鲜农产品挥发性氨气测试系统,分析了传感器的交叉敏感性和低温高湿环境下的稳定性,最后,对实际测试结果进行了主成分分析和Pearson相关分析。试验结果表明,该无芯片RFID传感器中心谐振频率为2.25 GHz,加载金属短路后增益提升0.13 dB,在实验室氨气质量浓度0~100 mg/L环境下灵敏度达到0.11 dB·L/mg,实际测试过程中,鸡肉氨气传感响应值较高,为9.0 dB;虾肉氨传感响应值较低,为4.5 dB。此外,传感器检测响应能有效区分干扰气体(H_(2)S、CO_(2)、CH_(4)、C2H5OH),相关系数绝对均值均小于0.5;在低温高湿环境下,传感器能够有效完成氨气检测,且稳定性良好。展开更多
文摘This paper presents a distributed wireless sensor network for multiple mobile agents localization. Localization of mobile agents, such as mobile robots, humans, and moving objects, in an indoor space is essential for robot-robot interaction (RRI) and human-robot interaction (HRI). The standard localization system, which is based on sensors installed in the robot body, is not suitable for multiple agents. Therefore, the concept of sensor network, which uses wireless sensors distributed in a specified space, is used in this study. By analyzing related studies, two solutions are proposed for the localization of mobile agents including humans: a new hardware system and a new software algorithm. The first solution focuses on the architectural design of the wireless sensor network for multiple agent localization. A passive RFID system is used, and then the architecture of the sensor network is adapted to suit the target system. The second solution centers on a localization algorithm based on the sensor network. The proposed localization algorithm improves the accuracy in the multiple agent localization system. The algorithm uses the displacement conditions of the mobile agents and the recognition changes between the RFID tags and RFID reader. Through experiments using a real platform, the usefulness of the proposed system is verified.
文摘电力设备数字孪生技术的发展推动了各类新型传感技术在电力行业中的应用,并亟需一条稳定、明确的数据上云渠道,以供给电力设备孪生体进行更加深入的状态分析及故障预测。为此,研制了一种带有金属反射板的双天线射频识别(radio frequency identification,RFID)加速度与温度传感器,并设计了RFID传感系统内的数据包格式以及传感数据经由边缘网关通过4G网络以消息队列遥测传输(messagequeuingtelemetrytransport,MQTT)协议上传至物联网云平台的数据传输通道,然后以OFPSZ-150000/220变压器为例进行了传感器测试和数据传输协议的应用。结果表明:所设计的数据传输协议丢包率主要存在于RFID传感器信道内,在2 m内的丢包率为11.3%,在最远通信距离3 m处的丢包率为38.2%,在数据经由边缘网关上云的信道中几乎不存在数据包的丢失问题。研究表明所设计的RFID传感器具有一定的实用性,且数据通信协议通道是稳定可靠的。
