Estimation And Tracking Algorithm For Autonomous Vehicles And Humans

Autonomous driving systems have experienced impressive growth in recent years. The present research community is working on several challenging aspects, such as, tracking, localization, path planning and control. In this thesis, first, we focus on tracking system and present a method to accurately track a moving vehicle. In the vehicle tracking, considering the proximity of surrounding vehicles, it is critical to detect their unusual maneuvers as quickly as possible, especially when autonomous vehicles operate among human-operated traffic. In this work, we present an approach to quickly detect lane-changing maneuvers of the nearby vehicles. The proposed algorithm is based on the optimal likelihood ratio test, known as Page test. Second, we consider another form of tracking: tracking the movements of humans in indoor settings. Indoor localization of staff and patients based on radio frequency identification (RFID) technology has promising potential application in the healthcare sector. The use of an active RFID in real-time indoor positioning system without any sacrifice of localization accuracy is intended to provide security, guidance and support service to patients. In this paper maximum likelihood estimation along with its Cramer-Rao lower bound of the locations of active RFID tags are presented by exploring the received signal strength indicator which is collected at the readers. The performance of real-time localization system is implemented by using an extended Kalman filter (EKF)

Critical Management Issues for Implementing RFID in Supply Chain Management

The benefits of radio frequency identification (RFID) technology in the supply chain are fairly compelling. It has the potential to revolutionise the efficiency, accuracy and security of the supply chain with significant impact on overall profitability. A number of companies are actively involved in testing and adopting this technology. It is estimated that the market for RFID products and services will increase significantly in the next few years. Despite this trend, there are major impediments to RFID adoption in supply chain. While RFID systems have been around for several decades, the technology for supply chain management is still emerging. We describe many of the challenges, setbacks and barriers facing RFID implementations in supply chains, discuss the critical issues for management and offer some suggestions. In the process, we take an in-depth look at cost, technology, standards, privacy and security and business process reengineering related issues surrounding RFID technology in supply chains

Energy Efficient Protocols for Active RFID

Radio frequency identification (RFID) systems come in different flavours; passive, active, semi-passive, or semi-active. Those different types of RFID are supported by different, internationally accepted protocol standards as well as by several accepted proprietary protocols. Even though the diversity is large between the flavours and between the standards, the RFID technology has evolved to be a mature technology, which is ready to be used in a large variety of applications. This thesis explores active RFID technology and how to develop and apply data communication protocols that are energy efficient and which comply with the different application constraints. The use of RFID technology is growing rapidly, and today mostly “passive” RFID systems are used because no onboard energy source is needed on the transponder (tag). However, the use of “active” RFID-tags with onboard power sources adds a range of opportunities not possible with passive tags. Besides that Active RFID offers increased working distance between the interrogator (RFID-reader) and tags, the onboard power source also enables the tags to do sensor measurements, calculations and storage even when no RFID-reader is in the vicinity of the tags. To obtain energy efficiency in an Active RFID system the communication protocol to be used should be carefully designed. This thesis describes how energy consumption can be calculated, to be used in protocol definition, and how evaluation of protocols in this respect can be made. The performance of such a new protocol, in terms of energy efficiency, aggregated throughput, delay, and number of collisions in the radio channel is evaluated and compared to an existing, commercially available protocol for Active RFID, as well as to the IEEE standard 802.15.4 (used, e.g., in the Zigbee medium-access layer). Simulations show that, by acknowledging the payload and using deep sleep mode on the tag, the lifetime of a tag is increased. For all types of protocols using a radio channel, when arbitrating information, it is obvious that the utilization of that channel is maximized when no collisions occur. To avoid and minimize collisions in the media it is possible to intercept channel interference by using carrier sense technology. The knowledge that the channel is occupied should result in a back-off and a later retry, instead of persistently listening to the channel which would require constant energy consumption. We study the effect on tag energy cost and packet delay incurred by some typical back-off algorithms (constant, linear, and exponential) used in a contention based CSMA/CA (Carrier Sense Multiple Access/ Collision Avoidance) protocol for Active RFID communication. The study shows that, by selecting the proper back-off algorithm coefficients (based on the number of tags and the application constraints), i.e., the initial contention window size and back-off interval coefficient, the tag energy consumption and read-out delays can be significantly lowered. The initial communication between reader and tag, on a control channel, establishes those important protocol parameters in the tag so that it tries to deliver its information according to the current application scenario in an energy efficient way. The decision making involved in calculating the protocol parameters is conducted in the local RFID-reader for highest efficiency. This can be done by using local statistics or based on knowledge provided by the logistic backbone databases. As the CMOS circuit technology evolves, new possibilities arise for mass production of low price and long life active tags. The use of wake-up radio technology makes it possible for active tags to react on an RFID-reader at any time, in contrast to tags with cyclic wake-up behaviour. The two main drawbacks with an additional wake-up circuit in a tag are the added die area and the added energy consumption. Within this project the solution is a complete wake-up radio transceiver consisting of only one hi-frequency very low power, and small area oscillator. To support this tag topology we propose and investigate a novel reader-tag communication protocol, the frequency binary tree protocol

Analysis of the scalability of UWB indoor localization solutions for high user densities

Radio frequency (RF) technologies are often used to track assets in indoor environments. Among others, ultra-wideband (UWB) has constantly gained interest thanks to its capability to obtain typical errors of 30 cm or lower, making it more accurate than other wireless technologies such as WiFi, which normally can predict the location with several meters accuracy. However, mainly due to technical requirements that are part of the standard, conventional medium access strategies such as clear channel assessment, are not straightforward to implement. Since most scientific papers focus on UWB accuracy improvements of a single user, it is not clear to which extend this limitation and other design choices impact the scalability of UWB indoor positioning systems. We investigated the scalability of indoor localization solutions, to prove that UWB can be used when hundreds of tags are active in the same system. This paper provides mathematical models that calculate the theoretical supported user density for multiple localization approaches, namely Time Difference of Arrival (TDoA) and Two-Way Ranging (TWR) with different MAC protocol combinations, i.e., ALOHA and TDMA. Moreover, this paper applies these formulas to a number of realistic UWB configurations to study the impact of different UWB schemes and settings. When applied to the 802.15.4a compliant Decawave DW1000 chip, the scalability dramatically degrades if the system operates with uncoordinated protocols and two-way communication schemes. In the best case scenario, UWB DW1000 chips can actively support up to 6171 tags in a single domain cell (no handover) with well-selected settings and choices, i.e., when adopting the combination of TDoA (one-way link) and TDMA. As a consequence, UWB can be used to simultaneously localize thousands of nodes in a dense network. However, we also show that the number of supported devices varies greatly depending on the MAC and PHY configuration choices

Joint design of RFID reader and tag anti-collision algorithms: a cross-layer approach

This paper investigates the potential interactions between reader and tag anti-collision algorithms of passive RFID (radio frequency identification) systems. Conventionally, reader and tag anti-collision algorithms are designed by assuming that they are independent from each other. In practice, however, readers and tags usually operate in the same frequency band. Therefore, contention between their transmissions can also potentially arise. Furthermore, reader anti-collision policies directly influence the way in which tags are activated, and thus also the way in which they collide when responding to reader’s requests. In view of this and considering the growing numbers of readers and tags, independence of both schemes can not longer be considered as a realistic assumption. This paper partially fills this gap by proposing a new cross-layer framework for the joint evaluation and optimization of reader and tag anticollision algorithms. Furthermore, the paper proposes a new approach, based on a Markov model, which allows capacity and stability analysis of asymmetrical RFID systems (i.e., when readers and tags experience different channel and queuing states). The model captures the dynamics of tag activation and tag detection processes of RFID. It also represents a first step towards a joint design of physical (PHY) and medium access control layers (MAC) of RFID. The results indicate that the proposed approach provides benefits in terms of stability and capacity over conventional solutions even when readers and tags operate in different channels. The results also provide useful guidelines towards the cross-layer design of future RFID platforms

Energy efficient anti-collision algorithm for the RFID networks

Energy efficiency is crucial for radio frequency identification (RFID) systems as the readers are often battery operated. The main source of the energy wastage is the collision which happens when tags access the communication medium at the same time. Thus, an efficient anti-collision protocol could minimize the energy wastage and prolong the lifetime of the RFID systems. In this regard, EPCGlobal-Class1-Generation2 (EPC-C1G2) protocol is currently being used in the commercial RFID readers to provide fast tag identification through efficient collision arbitration using the Q algorithm. However, this protocol requires a lot of control message overheads for its operation. Thus, a reinforcement learning based anti-collision protocol (RL-DFSA) is proposed to provide better time system efficiency while being energy efficient through the minimization of control message overheads. The proposed RL-DFSA was evaluated through extensive simulations and compared with the variants of EPC-Class 1 Generation 2 algorithms that are currently being used in the commercial readers. The results show conclusively that the proposed RL-DFSA performs identically to the very efficient EPC-C1G2 protocol in terms of time system efficiency but readily outperforms the compared protocol in the number of control message overhead required for the operation

PERFORMANCE ANALYSIS OF SECURITY MEASURES IN NEAR FIELD COMMUNICATION

Nowadays near field communication are largely used in so many different applications for the convenience and ease of use they provide. They store and exchange many personal data, some of them requires more security than others, due to the value they poses, such as banking information and personal identification. And maintaining high level of security is task of the utmost priority. The main focus of this thesis is establishing a knowledge base for different NFC/RFID devices. Evaluating the different encryption algorithms used currently, based on their encryption/decryption time, their immunity to brute force attack, and the amount of power needed to execute them. The encryption algorithms will be implemented using Python programing language and tested on a windows computer in order to test their immunity against brute force attack. Encryption/decryption time and the power usage will be tested on a Raspberry Pi, for the similarities it has with modern mobile devices.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format