RTSense: passive RFID based temperature sensing
RTSense: passive RFID based temperature sensing
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DOI：
10.1145/3384419.3430729
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
S. Pradhan;L. Qiu
中科院分区：
文献类型：
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作者：
S. Pradhan;L. Qiu
无源射频识别（RFID）标签很有吸引力，因为它们成本低，不需要电池，而且易于部署。这项技术传统上被用来识别附着在物体上的标签。在本文中，我们探索将无源RFID标签转变为无电池温度传感器的可行性。RFID标签的阻抗随着温度的变化而变化，这种变化会在标签反射的信号中表现出来。这为在供应链管理或库存跟踪中使用已部署的商用现货（COTS） RFID读写天线基础设施的无源RFID标签实现无电池温度传感提供了机会。然而，在环境变化的情况下，实现高精度和鲁棒性是具有挑战性的。为了应对这些挑战，我们首先开发了一个详细的分析模型，以捕获温度变化对标签阻抗和反射信号的所得相位的影响。然后我们建立了一个使用一对标签的系统，它们对温度变化有不同的反应，以抵消其他环境影响。通过广泛的评估，我们证明了我们的模型是准确的，我们的系统可以在2.9摄氏度的中值误差内估计温度，并以与环境无关的方式支持3.5米的正常读取范围。
Passive radio-frequency identification (RFID) tags are attractive because they are low cost, battery-free, and easy to deploy. This technology is traditionally being used to identify tags attached to the objects. In this paper, we explore the feasibility of turning passive RFID tags into battery-free temperature sensors. The impedance of the RFID tag changes with the temperature and this change will be manifested in the reflected signal from the tag. This opens up an opportunity to realize battery-free temperature sensing using a passive RFID tag with already deployed Commercial Off-the-Shelf (COTS) RFID reader-antenna infrastructure in supply chain management or inventory tracking. However, it is challenging to achieve high accuracy and robustness against the changes in the environment. To address these challenges, we first develop a detailed analytical model to capture the impact of temperature change on the tag impedance and the resulting phase of the reflected signal. We then build a system that uses a pair of tags, which respond differently to the temperature change to cancel out other environmental impacts. Using extensive evaluation, we show our model is accurate and our system can estimate the temperature within a 2.9 degree centigrade median error and support a normal read range of 3.5 m in an environment-independent manner.