Toward a Wearable RFID System for Real-Time Activity Recognition Using Radio Patterns

Abstract

Elderly care is one of the many applications supported by real-time activity recognition systems. Traditional approaches use cameras, body sensor networks, or radio patterns from various sources for activity recognition. However, these approaches are limited due to ease-of-use, coverage, or privacy preserving issues. In this paper, we present a novel wearable Radio Frequency Identification (RFID) system aims at providing an easy-to-use solution with high detection coverage. Our system uses passive tags which are maintenance-free and can be embedded into the clothes to reduce the wearing and maintenance efforts. A small RFID reader is also worn on the user's body to extend the detection coverage as the user moves. We exploit RFID radio patterns and extract both spatial and temporal features to characterize various activities. We also address the issues of false negative of tag readings and tag/antenna calibration, and design a fast online recognition system. Antenna and tag selection is done automatically to explore the minimum number of devices required to achieve target accuracy. We develop a prototype system which consists of a wearable RFID system and a smartphone to demonstrate the working principles, and conduct experimental studies with four subjects over two weeks. The results show that our system achieves a high recognition accuracy of 93.6 percent with a latency of 5 seconds. Additionally, we show that the system only requires two antennas and four tagged body parts to achieve a high recognition accuracy of 85 percent.

Towards Human Activity Recognition: A Hierarchical Feature Selection Framework

“…One major drawback of a single accelerometer is that they easily fail to discriminate similar activities. Besides an accelerometer, RFID technology is widely used, and it also helps to recognize human activities [25]. For example, Kim et al [26] constructed an indoor healthcare monitoring system to track the elderly who wore RFID tags.…”

A home security system for seniors based on the beacon technology

“…The simulation results of the work of the aforementioned authors showed smaller positioning error compared to that of other methods. The later study proposed using RFID to detect activities in elderly people; it suggests attaching RFID tags onto clothing of the elderly people, having them carry RFID readers, installing UHF RFID readers indoors, and collecting different positions of the elderly people and the received signal strength of RFID during different activities; the collected data is then run through support vector machines for learning and categorizing signals and behaviors, so that when a mobile phone registers RFID received signal strength, it can determine current position and behavior of the elderly people. Since the aforementioned approach focuses on positioning the indoor location of elderly people and requires equipment such as mobile devices and RFIDs, which can be troublesome for elderly people in terms of portability and operation, such as battery maintenance, the positioning feature of this research emphasizes beacon power, received signal strength, and state machines so as to reduce the number of sensor installations needed and hardware costs.…”

“…Table is an analysis of differences between our proposed method and studies . The analysis features comparison of factors including complexity of system operation, number of sensors required, frequency of battery change, cost for system establishment, and adaptability of system environment.…”

“…The analysis features comparison of factors including complexity of system operation, number of sensors required, frequency of battery change, cost for system establishment, and adaptability of system environment. The study of Wang et al called for RFID tag, RFID reader, and UHF RFID Reader; although this refrains the elderly from additional system operation, RFID Readers's battery needs constant change. Moreover, UHF RFID Readers are more costly and demand extra equipment setup fees for different indoor areas; they also require professional technicians to set it up and assess setup locations.…”

RFID Tag as a Sensor - A Review on the Innovative Designs and Applications

“…The measured performance indicates a possible application of these body-worn tags for continuous tracking of human movements. A study on wearable RFID based system for real-time activity recognition is conducted in [75], where recognition is realised by exploiting RFID radio patterns towards easy-to-use solution and high detection coverage. In addition to custom-designed systems, there are specific RFID based platforms suitable for human activity detection, such as iGlove, iBracelet, and WISP [76].…”