Ultra Wideband Impulse Radio for Wireless Sensing and Identification

Ubiquitous computing and Internet-of-Things (IoT) implies an untapped opportunity in the realm of information and communication technology, in which a large number of micro-devices with communication and/or computing capabilities, provides connectivity for anything, by anyone at anytime and anywhere. Especially, these devices can be equipped with sensors and actuators that interact with our living environment. Barcode, smart contactless card, Radio Frequency Identification (RFID) systems, wireless sensor network (WSN), and smart mobile phones are some examples which can be utilized in ubiquitous computing. RFIDs and WSN have been recognized as the two promising enablers for realization of ubiquitous computing. They have some great features such as low-cost and small- size implementation, non-line of sight operation, sensing possibilities, data storing ability, and positioning. However, there are several challenges which need to be addressed, such as limited life time for battery powered device, maintenance cost, longer operation range, higher data rate, and operation in dense multipath and multiuser environment. Ultra-Wideband Impulse Radio (UWB-IR) with its huge advantages has been recognized as a great solution for future WSN and RFID. UWB-IR technique has the possibility of achieving Gb/s data rate, hundreds of meter operation range, pJ energy per bit, centimeter accuracy of positioning, and low cost implementation. In this work utilization of UWB-IR in WSN and RFID is investigated. A wireless sensor network based on UWB-IR is proposed focusing on low-cost and low-power implementation. Our contribution is to imply two different architectures in base station and sensor nodes to satisfy power, complexity and cost constraints. For sensor nodes, an autonomous UWB-IR detection is proposed, which detects the UWB signal autonomously and no restrict synchronization is required. It reduces the circuit complexity significantly. The performance in term of bit-error-rate is compared with two other common detection techniques. It is shown that the new detection is more robustness to timing jitter and clock skew, which consequently reduces the clock and synchronization requirements considerably. A novel wireless sensing and identification system, based on remote-powered tag with asymmetric wireless link, is proposed. Our innovative contribution is to deploy two different UWB and UHF communication techniques in uplink and downlink respectively. In the proposed system, tags capture the required power supply from different environmental sources (e.g. electromagnetic wave transmitted by a reader) and transmit data through an ultra-low power impulse UWB link. A new communication protocol is devised based on slotted-aloha anti-collision algorithm. By introducing several improvements including of pipelined communication, adaptive frame size, and skipping idle slots, the system throughput of more than 2000 tags/s is achieved. To prove the system concept a single chip integrated tag is implemented in UMC 0.18μm CMOS process. The measurement results show the minimum sensitivity of -18.5 dB (14.1 μW) and adaptive data rate up to 10 Mb/s. It corresponds to 13.9 meters operation range, considering 4W EIRP, a matched antenna to the tag with 0dB gain, and free space path loss. This is a great improvement in operation range and data rate, compared with conventional passive RFID, which data rate is limited to a few hundreds of Kb/s. System integration in a Liquid-Crystal-polymer (LCP) substrate is investigated. The integration of a tunable UWB-IR transmitter and a power scavenging unit are studied. Our contribution includes embedding and modeling the RF components and antenna in substrate and co-optimizing the chip and package with on-chip versus off-chip passives trade-offs. Simulation results verify the potential of system-on-package solution for UWB integration. The effect of antenna miniaturization in a UWB system is studied. Our focus is to scale down a UWB antenna and optimize the performance through the chip-antenna co-design. A tunable impulse- UWB transmitter is designed in two cases - a conventional 50Ω design and a co-design methodology. The simulation results show that the standard 50Ω design technique can not reach the best condition in all cases, when a real antenna is placed into the system. The performance can be improved significantly when doing codesign. The antennas and UWB transmitter performances are evaluated in a given UWB systems. It is shown that the operation distance at a target performance is reduced with antenna scaling factor and it can be compensated by antenna-transceiver co-design. The result proves the importance of antenna-transceiver codesign, which needs to be addressed in the earliest phases of the design flow.QC 2010070

Review of the UPFC Different Models in Recent Years

<p>Unified Power Flow Controller (UPFC) is one of the most intriguing and, potentially, the most versatile classes of Flexible <em>AC Transmission Systems</em> (FACTS) devices. The UPFC is a device which can control simultaneously tree parameters line impedance, voltage, phase angle and dynamic compensation of AC power system. In order to analyse its true effects on power systems, it is important to model its constraints, due to various ratings and operating limits. This paper reviews on the different models of UPFC used in recent years and gives sets of information for each model of the UPFC in AC transmission. Then the different models are compared and features of each model are examined.</p

A Review on Speed Control Techniques of Separately Excited DC Motor

Nowadays, many moving devices receive their energy from a battery. DC motor is the most suitable option for these systems. In addition, the speed of these motors can be controlled easily and in the extensive range. Intelligent control methods are widely used in control of the industrial processes due to simplicity and high capabilities. In this paper, the fuzzy resistance speed controller has been designed and presented for DC motor. This controller stabilizes speed of motor in the desirable path despite changes of load torque or change of motor elements. One of the other features of this controller is the multivariate objective function which is able to supply dynamical behavior of the motor. Rapid response, permanent fault and low overshoot are about the other advantages of this method. DOI:  http://dx.doi.org/10.11591/telkomnika.v13i1.7004

Review of Dynamic Voltage Restorer Application for Compensation of Voltage Harmonics in Power Systems

Power distribution networks are considered the main link between power industry and consumers and they are exposed to public judgment and evaluation more than any other section. Thus, it is essential to study power quality in distribution section. On the other hand, power distribution networks have always been exposed to traditional factors such as  voltage sag, voltage swell, harmonics and capacitor switching which destruct sinusoidal waveforms and decrease power quality as well as network reliability. One of the methods by which power quality problems might be addressed is to apply power electronic devices in the form of custom power devices. One of such devices is Dynamic Voltage Restorer (DVR) which is connected in series to distribution networks. At the same time, through injection of voltage to the network it is able to control voltage amplitude and phase. It is  adopted lend to compensate for voltage sags through injecting series and synchronous three phase voltage. This paper reviews on the application of DVR for Voltage Compensation in recent years and gives sets of information for each control of the DVR in distribution networks

Far-field RF Powering System for RFID and Implantable Devices with Monolithically Integrated On-Chip Antenna

A fully integrated far-field powering system for RFID and implantable devices with monolithically fully integrated on-chip antenna in 0.18μm CMOS is presented. The chip receives power, clock and data wirelessly through RF signal at all the three ISM bands of 915 MHz, 2.45 GHz and 5.8 GHz. Measurements show a minimum input power of -19.41 dBm at 900MHz for chip operation, corresponding to 15.7 meter of operation range with an off-chip 0dB gain antenna. On the other hand, with its on-chip antenna at 5.8 GHz, the chip can be powered-up up to 7.5 cm distance. This is a huge improvement in terms of operation distance compared with other reported similar works with on-chip antenna as well as the off-chip antennas. © 2010 IEEE.status: publishe

Finger Angle-Based Hand Gesture Recognition for Smart Infrastructure Using Wearable Wrist-Worn Camera

The arising of domestic robots in smart infrastructure has raised demands for intuitive and natural interaction between humans and robots. To address this problem, a wearable wrist-worn camera (WwwCam) is proposed in this paper. With the capability of recognizing human hand gestures in real-time, it enables services such as controlling mopping robots, mobile manipulators, or appliances in smart-home scenarios. The recognition is based on finger segmentation and template matching. Distance transformation algorithm is adopted and adapted to robustly segment fingers from the hand. Based on fingers’ angles relative to the wrist, a finger angle prediction algorithm and a template matching metric are proposed. All possible gesture types of the captured image are first predicted, and then evaluated and compared to the template image to achieve the classification. Unlike other template matching methods relying highly on large training set, this scheme possesses high flexibility since it requires only one image as the template, and can classify gestures formed by different combinations of fingers. In the experiment, it successfully recognized ten finger gestures from number zero to nine defined by American Sign Language with an accuracy up to 99.38%. Its performance was further demonstrated by manipulating a robot arm using the implemented algorithms and WwwCam to transport and pile up wooden building blocks

A Remote-Powered RFID TAG with 10Mb/s UWB Uplink and -18.5dBm-Sensitivity UHF Downlink in 0.18um CMOS

status: publishe