Indoor localization systems-tracking objects and personnel with sensors, wireless networks and RFID

Advances in ubiquitous mobile computing and rapid spread of information systems have fostered a growing interest in indoor location-aware or location-based technologies. In this paper we will introduce the primary technologies used in indoor localization systems by classifying them in three categories: Non-RF technologies, Active-RF technologies and Passive-RF technologies. Both commercialized products and research prototypes in all categories are involved in our discussion. The Passive-RF technologies are further divided into “Mobile tag” and “Mobile reader” systems. We expect such classification can cover most of the indoor localization systems. Features of these systems are briefly compared at the end of this paper

UWB-assisted real-time localization in wireless sensor networks

A safety monitoring and accident warning system for underground construction site has been designed in our previous work based on wireless sensor networks (WSNs). Real-time localization of mobile targets is crucial for tracking the related incidents. However, the current RSSI-based localization approach struggles to achieve the required performance. This is due to the limited ranging accuracy of RSSI devices. In this paper, we investigate various ways of improving the localization accuracy and propose our solution of a hybrid UWB-assisted approach. We argue that a hybrid UWB-assisted RSSI ranging has the best overall performance for our application. We show with both mathematical analysis and demonstration system that, instead of implementing a full UWB network, our approach can improve the accuracy to our desired level with only a small number of additional UWB anchor nodes. © 2013 IEEE

RFID based automatic speed limit warning system

Speeding is one of the major causes of road accidents. As drivers usually claim they exceed the speed limit unintentionally, having an in-vehicle automatic speed limit warning system could help to prevent a significant number of speeding and accidents from happening. Existing systems cannot provide consistent and satisfactory performance. In this paper we investigated automatic speed limit transmission based on RFID technologies. We conclude that both passive and active RFID systems show potential in such scenario, but are suitable for different scales of applications. For both technologies, challenges are identified and addressed, with system prototypes proposed and demonstration systems developed to prove the feasibility of our design concept

Connectionless indoor inventory tracking in Zigbee RFID sensor network

Abstract: Zigbee is one of the most exciting wireless sensor network (WSN) technologies for monitoring and control. In our previous research, an integrated Zigbee RFID sensor network was designed as an ‘all-in-one’ system solution for Humanitarian Logistics Center (HLC) resource management. Various field trials, which have justified the feasibility and features of such a system structure, have also revealed the requirement for simple yet reliable mobile tracking architecture for Zigbee network. In this paper a connectionless tracking architecture based on Zigbee RFID sensor network is proposed for inventory management applications. Such architecture features a consistent network structure, low hardware energy consumption and no accumulated error for localization algorithms with the least additional cost and hardware required on top of the existing Zigbee RFID sensor network systems. A simple demo system is also developed to demonstrate the feasibility of our design

Zigbee enabled radio frequency identification system

The Radio Frequency Identification (RFID) system is a widely used Auto-ID technology today to identify and track objects and people in manufacturing, inventory management, retailing, and security applications. The Zigbee technology, which is a recently emerged network communication protocol based on the IEEE 802.15.4 standard, provides a self-organized mesh network topology with a power-effective, low data rate and multi-hop data transmission. The RFID system could profit some of its features by introducing the Zigbee technology into the existing RFID architectures, such as having extended effective range, improving network flexibility and having compatibility with other Zigbee enabled environment systems. In this paper we first discuss the possible benefits and applications while applying Zigbee to the different parts of the RFID system. Then an integrated Zigbee RFID system architecture is discussed and a demo system is described at the end of the paper

An integrated information management model for proactive prevention of struck-by-falling-object accidents on construction sites

The construction industry is one of the most hazardous industries in many countries. Struck-by-falling-object accidents are not given adequate attention even though they are of great importance on construction sites. The objective of this paper is to analyze the proactively preventive information requirement of struck-by-falling-object accidents and propose an integrated information management model using a ZigBee RFID sensor network to fulfill these requirements. First, the frequency of particular type of objects is analyzed based on vast historical accident cases. Next, this paper analyzes the proactively preventive information requirement of struck-by-falling-object accidents and brought forth an integrated information management model. Furthermore, considering the crucial and controllable objects, an integrated information management model is proposed. This study would provide a possible approach for tracking struck-by-falling-object accidents based on real-time information for proactive prevention and could serve as a foundation for further study. © 2012 Elsevier B.V. All rights reserved

RFID based automatic speed limit warning system

Speeding is one of the major causes of road accidents. As drivers usually claim they exceed the speed limit unintentionally, having an in-vehicle automatic speed limit warning system could help to prevent a significant number of speeding and accidents from happening. Existing systems cannot provide consistent and satisfactory performance. In this paper we investigated automatic speed limit transmission based on RFID technologies. We conclude that both passive and active RFID systems show potential in such scenario, but are suitable for different scales of applications. For both technologies, challenges are identified and addressed, with system prototypes proposed and demonstration systems developed to prove the feasibility of our design concept

Connectionless indoor inventory tracking in Zigbee RFID sensor network

Abstract: Zigbee is one of the most exciting wireless sensor network (WSN) technologies for monitoring and control. In our previous research, an integrated Zigbee RFID sensor network was designed as an ‘all-in-one’ system solution for Humanitarian Logistics Center (HLC) resource management. Various field trials, which have justified the feasibility and features of such a system structure, have also revealed the requirement for simple yet reliable mobile tracking architecture for Zigbee network. In this paper a connectionless tracking architecture based on Zigbee RFID sensor network is proposed for inventory management applications. Such architecture features a consistent network structure, low hardware energy consumption and no accumulated error for localization algorithms with the least additional cost and hardware required on top of the existing Zigbee RFID sensor network systems. A simple demo system is also developed to demonstrate the feasibility of our design

RFID sensor network network architectures to integrate RFID, sensor and WSN

RFID sensor network network architectures to integrate RFID, sensor and WS

HEER - a delay-aware and energy-efficient routing protocol for wireless sensor networks

Minimizing energy consumption to maximize network lifetime is one of the crucial concerns in designing wireless sensor network routing protocols. Cluster-based protocols have shown promising energy-efficiency performance, where sensor nodes take turns to act as cluster heads (CHs), which carry out higher-level data routing and relaying. In such case the energy consumption is more evenly distributed for all the nodes. However, most cluster-based protocols improve energy-efficiency at the cost of transmission delay. In this paper, we propose an improved delay-aware and energy-efficient clustered protocol called Hamilton Energy-Efficient Routing Protocol (HEER). HEER forms clusters in the network initialization phase and links members in each cluster on a Hamilton Path, constructed using a greedy algorithm, for data transmission purpose. No cluster reformation is required and the members on the path will take turns to become cluster head. The design allows HEER to save on network administration energy and also balance the load comparing to traditional cluster-based protocols. The algorithms designed in HEER also means that it does not suffer long delay and does not require each node to have global location information comparing with classic chain-based protocols such as PEGASIS and its variations. We implemented the HEER protocol in MATLAB simulation and compared it with several cluster-based and chain-based protocols. We found that HEER is able to achieve an improved network lifetime over the current protocols while maintaining the average data transmission delay. In the simulation, HEER achieved 66.5% and 40.6% more rounds than LEACH and LEACH-EE, which are cluster-based protocols. When compared with chain-based protocols (PEGASIS and Intra-grid-PEGSIS), HEER managed 21.2 times and 16.7 times more rounds than PEGASIS and Intra-grid-PEGASIS respectively. In addition, HEER can eliminated 90% of transmission delay comparing to LEACH and LEACH-EE and 99% comparing with PEGASIS and Intra-grid-PEGASIS