In time-of-arrival (TOA) based indoor human tracking system, the human body mounted with the target sensor can cause non-line of sight (NLOS) scenario and result in significant ranging error. However, the previous studies on the behavior of indoor TOA ranging did not take the effects of human body into account. In this paper, measurement of TOA ranging error has been conducted in a typical indoor environment and sources of inaccuracy in TOA-based indoor localization have been analyzed. To quantitatively describe the TOA ranging error caused by human body, we introduce a statistical TOA ranging error model for body mounted sensors based on the measurement results. This model separates the ranging error into multipath error and NLOS error caused by the creeping wave phenomenon. Both multipath error and NLOS error are modeled as a Gaussian variable. The distribution of multipath error is only relative to the bandwidth of the system while the distribution of NLOS error is relative to the angle between human facing direction and the direction of transmitter–receiver, signal to noise ratio and bandwidth of the system, which clearly shows the effects of human body on TOA ranging.

Modeling the Effect of Human Body on TOA Based Indoor Human Tracking

For time-of-arrival-(TOA)-based indoor human tracking system, the wireless channel between human body surface and external reference node can be regarded as the source of inaccuracy. Since only the arrival time of direct path provides accurate range estimate, the nonline of sight caused by human body leads to undetectable direct path condition and thus results in a significant distance measurement error. In this paper, we measured TOA ranging error for indoor human tracking applications inside a typical office environment. A large number of TOA ranging samples was obtained and statistically analyzed. The TOA ranging error was modeled as a Gaussian random variable with the parameters, including position of target sensor, angle between human facing direction, and direction of transmitter–receiver, signal-to-noise ratio, and bandwidth of the system. As a validation of proposed model, excellent agreement has been found between empirical measurement and model-based software simulation.

Toward Accurate Human Tracking: Modeling Time-of-Arrival for Wireless Wearable Sensors in Multipath Environment

Precision ultra-wideband ranging requires accurate estimation of time of arrival (TOA). The threshold-based TOA estimation has attracted considerable interest due to its simplicity. In this paper, we propose a technique to set the threshold as a function of delay instead of a single value as in conventional methods. Simulation results show that the proposed method is superior to conventional methods.

Delay-Dependent Threshold Selection for UWB TOA Estimation

Autonomy of vehicles is a widely discussed topic, increasing the need for low power, inexpensive and precise localization and navigation. Due to ongoing research and standardization in last decades, ultra-wideband (UWB) based localization technology is more and more ready for large scale usage. In this paper we propose an embedded UWB localization system, consisting of an inexpensive, low power hardware platform deploying an IEEE 802.15.4a-2011 UWB-PHY standard conform RF chip, enabling communication and localization, a software framework, and localization algorithms. The key contribution of the paper is this system concept and experimental results using a developed system in an underground parking garage. Within this system evaluation we show in an accuracy analysis an achievable positioning error of around 30 cm. Furthermore we show the useage of such an UBW localization system in an use case near scenario.

Design of an embedded UWB hardware platform for navigation in GPS denied environments

The location of people, mobile terminals and equipment is highly desirable for operational enhancements in the mining industry. In an indoor environment such as a mine, the multipath caused by reflection, diffraction and diffusion on the rough sidewall surfaces are the main sources of range measurement errors. In this paper, a UWB time of flight based localization system is proposed to address the multipath effect in underground mines. To reduce the communication cost and time delay of localization in such a chain type wireless network, a distributed localization algorithm based on particle swarm optimization (PSO) is proposed and implemented on the blind node (the node to be localized). Without extra hardware needed, an accurate but low cost localization system has been achieved. Experimental results verify the proposed scheme

A Distributed UWB-based Localization System in Underground Mines

The aspects of energy conservation and environmental protection are the need of the hour. Hence, the battery electric vehicles came into existence and are operated for various purposes. The most important part of these vehicles is the safety systems. The operation of the safety systems installed in Pedal Assembly, Dash Board, Battery pack, Motor Controller can be made less complicated and faster by using Controller Area Network (CAN) protocol. Keeping design simplicity in mind CAN protocol is used to make the system less bulky by reducing the number of wiring. In this paper, we see how the Electric Vehicle runs by using this protocol in accordance with the FSAE standards. The main motive of the paper is to improve the safety and reliability of the vehicle which is achieved by the application of the CAN transmission protocol.

Performance analysis of controller area network based safety system in an electric vehicle

Fire and gas safety FGS system are important tools for safeguarding process plants and production facilities that handle flammable and toxic materials. In general, a conventional fire and gas system has several shortcomings, such as weakness to noise and false alarms. In order to overcome these shortcomings, controller area network CAN-based FGS system has been implemented in our previous work. Further, considering that FGS systems are employed in hazardous environments, where wireless implementation of CAN is desirous, an attempt to make CAN wireless is carried out for these systems in this work, by using the radio protocol IEEE 802.15.4 to communicate CAN messages wireless. This work is a continuation of our previous work. Here the wired CAN interface is converted to wireless CAN and response time analysis of the system is done using CANoe v7.6.

Time analysis of wireless controller area network-based fire and gas safety system

This paper reviews the research work done on the Modeling and Analysis of Wireless Controller Area Network (WCAN). The controller area network (CAN) has been long regarded as the pioneer in standardizing vehicle bus standard. Its influence has even been reached out to various applications in industrial automation; which includes military, aviation, electronics and many others. With wireless technology becoming more pervasive, there is also a need for CAN too to migrate and evolve to its wireless counterpart [1]. A few methods were proposed in the last decade [2-6] that utilized the advantageous of CAN into a wireless network system called wireless controller area network (WCAN). This paper reviews these approaches of WCAN.

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Modeling and Analysis of Wireless Controller Area Network—A Review

The controller area network (CAN) is the pioneer in standardising vehicle and automation bus standards. For the wired CAN to meet the emergent pervasive wireless technology, wireless controller area network (WCAN) is introduced. WCAN is based on wireless token ring protocol (WTRP); a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message-based communication. CAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and better packet delivery ratio. WCAN is tested by simulation using QualNet and compared with IEEE 802.11 and is found to outperform it in ring network. The test results are validated using SAE benchmark.

Modelling, analysis and validation of wireless controller area network

It is widely known that Control Area Networks (CAN) are used in real-time, distributed and parallel processing which cover manufacture plants, humanoid robots, networking fields, etc., In applications where wireless conditions are encountered it is convenient to continue the exchange of CAN frames within the Wireless CAN (WCAN). The WCAN considered in this research is based on wireless token ring protocol (WTRP); a MAC protocol for wireless networks to reduce the number of retransmissions due to collision and the wired counterpart CAN attribute on message based communication. WCAN uses token frame method to provide channel access to the nodes in the system. This method allow all the nodes to share common broadcast channel by taken turns in transmitting upon receiving the token frame which is circulating within the network for specified amount of time. This method provides high throughput in bounded latency environment, consistent and predictable delays and good packet delivery ratio. The most important factor to consider when evaluating a control network is the end-to-end time delay between sensors, controllers, and actuators. The correct operation of a control system depends on the timeliness of the data coming over the network, and thus, a control network should be able to guarantee message delivery within a bounded transmission time. The proposed WCAN is modeled and simulated using QualNet, and its average end to end delay and packet delivery ratio (PDR) are calculated. The parameters boundaries of WCAN are evaluated to guarantee a maximum throughput and a minimum latency time, in the case of wireless communications, precisely WCAN.

Gerardine Immaculate Mary

Papers

Performance analysis of controller area network based safety system in an electric vehicle

Time analysis of wireless controller area network-based fire and gas safety system

Modeling and Analysis of Wireless Controller Area Network—A Review

Modelling, analysis and validation of wireless controller area network

Real time analysis of wireless controller area network