Optical Camera Communications: Principles, Modulations, Potential and Challenges

Optical wireless communications (OWC) are emerging as cost-effective and practical solutions to the congested radio frequency-based wireless technologies. As part of OWC, optical camera communications (OCC) have become very attractive, considering recent developments in cameras and the use of fitted cameras in smart devices. OCC together with visible light communications (VLC) is considered within the framework of the IEEE 802.15.7m standardization. OCCs based on both organic and inorganic light sources as well as cameras are being considered for low-rate transmissions and localization in indoor as well as outdoor short-range applications and within the framework of the IEEE 802.15.7m standardization together with VLC. This paper introduces the underlying principles of OCC and gives a comprehensive overview of this emerging technology with recent standardization activities in OCC. It also outlines the key technical issues such as mobility, coverage, interference, performance enhancement, etc. Future research directions and open issues are also presented

Perception Intelligence Integrated Vehicle-to-Vehicle Optical Camera Communication.

Ubiquitous usage of cameras and LEDs in modern road and aerial vehicles open up endless opportunities for novel applications in intelligent machine navigation, communication, and networking. To this end, in this thesis work, we hypothesize the benefit of dual-mode usage of vehicular built-in cameras through novel machine perception capabilities combined with optical camera communication (OCC). Current key conception of understanding a line-of-sight (LOS) scenery is from the aspect of object, event, and road situation detection. However, the idea of blending the non-line-of-sight (NLOS) information with the LOS information to achieve a see-through vision virtually is new. This improves the assistive driving performance by enabling a machine to see beyond occlusion. Another aspect of OCC in the vehicular setup is to understand the nature of mobility and its impact on the optical communication channel quality. The research questions gathered from both the car-car mobility modelling, and evaluating a working setup of OCC communication channel can also be inherited to aerial vehicular situations like drone-drone OCC. The aim of this thesis is to answer the research questions along these new application domains, particularly, (i) how to enable a virtual see-through perception in the car assisting system that alerts the human driver about the visible and invisible critical driving events to help drive more safely, (ii) how transmitter-receiver cars behaves while in the mobility and the overall channel performance of OCC in motion modality, (iii) how to help rescue lost Unmanned Aerial Vehicles (UAVs) through coordinated localization with fusion of OCC and WiFi, (iv) how to model and simulate an in-field drone swarm operation experience to design and validate UAV coordinated localization for group of positioning distressed drones. In this regard, in this thesis, we present the end-to-end system design, proposed novel algorithms to solve the challenges in applying such a system, and evaluation results through experimentation and/or simulation

Software-Defined Lighting.

For much of the past century, indoor lighting has been based on incandescent or gas-discharge technology. But, with LED lighting experiencing a 20x/decade increase in flux density, 10x/decade decrease in cost, and linear improvements in luminous efficiency, solid-state lighting is finally cost-competitive with the status quo. As a result, LED lighting is projected to reach over 70% market penetration by 2030. This dissertation claims that solid-state lighting’s real potential has been barely explored, that now is the time to explore it, and that new lighting platforms and applications can drive lighting far beyond its roots as an illumination technology. Scaling laws make solid-state lighting competitive with conventional lighting, but two key features make solid-state lighting an enabler for many new applications: the high switching speeds possible using LEDs and the color palettes realizable with Red-Green-Blue-White (RGBW) multi-chip assemblies. For this dissertation, we have explored the post-illumination potential of LED lighting in applications as diverse as visible light communications, indoor positioning, smart dust time synchronization, and embedded device configuration, with an eventual eye toward supporting all of them using a shared lighting infrastructure under a unified system architecture that provides software-control over lighting. To explore the space of software-defined lighting (SDL), we design a compact, flexible, and networked SDL platform to allow researchers to rapidly test new ideas. Using this platform, we demonstrate the viability of several applications, including multi-luminaire synchronized communication to a photodiode receiver, communication to mobile phone cameras, and indoor positioning using unmodified mobile phones. We show that all these applications and many other potential applications can be simultaneously supported by a single lighting infrastructure under software control.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111482/1/samkuo_1.pd

Structure and Functionality of Novel Nanocomposite Granules for a Pressure-Sensitive Ink with Applications in Touchscreen Technologies

Tactile sensors are now ubiquitous within human-computer interactions, where mouse and keyboard functionality can be replaced with a trackpad or touchscreen sensor. In most technologies the sensor can detect the touch location only, with no information given on the force of the touch. In this thesis, functional components of a novel nanocomposite ink are developed, which when printed, form a pressure-sensitive interface which can detect both touch location and touch force. The physical basis of the force-sensitive response is investigated for the touchscreen sensor as a whole, as well as the intrinsic force-sensitivity of the ink components. In an earlier form the nanocomposite ink, that was the starting point of this study, contained agglomerates of conductive nanoparticles which were formed during blending of the ink, and provided the electrical functionality of the sensor. Here, novel nanocomposite granules were pre-fabricated prior to inclusion in the ink. The granules were designed such that they exhibited well-defined size, structure and strength. Control of these parameters was achieved through selection of the granule constituents, as well as the energy and duration of the granulation process. When incorporated into the ink and screen-printed to form a pressure-sensitive layer in a touchscreen test device, the functional performance could be assessed. Sensors containing pre-formed granules showed improved optical transmission, compared to sensors containing the same mass loading of nanoparticles forming spontaneous agglomerates. Agglomerates tend to create a larger number of small scattering centres which scatter light to larger angles. The spatial variation in the force-resistance response, as well as the sensitivity of this response, was also linked to the distribution of the granules within the pressure-sensitive layer. The physical basis of the force-resistance response is two-fold. Firstly, mathematical simulations showed that deflection of the upper electrode increased the number of granules contacted with increasing applied force and therefore decreased the resistance through the sensor. Secondly, a force-sensitive resistance of the granules themselves was also observed at high forces. Analysis of the non-linear current-voltage characteristics suggested the presence of non-linear conduction pathways within the granules. Using a random resistor network model, the non-linear current contribution decreased after approximately 0.7 N force. To understand this effect, a model based on the physical basis of quantum tunnelling mechanisms was also applied, however this provided a poor fit to the data and no further understanding could be gained

NASA Tech Briefs, April 2011

Topics covered include: Amperometric Solid Electrolyte Oxygen Microsensors with Easy Batch Fabrication; Two-Axis Direct Fluid Shear Stress Sensor for Aerodynamic Applications; Target Assembly to Check Boresight Alignment of Active Sensors; Virtual Sensor Test Instrumentation; Evaluation of the Reflection Coefficient of Microstrip Elements for Reflectarray Antennas; Miniaturized Ka-Band Dual-Channel Radar; Continuous-Integration Laser Energy Lidar Monitor; Miniaturized Airborne Imaging Central Server System; Radiation-Tolerant, SpaceWire-Compatible Switching Fabric; Small Microprocessor for ASIC or FPGA Implementation; Source-Coupled, N-Channel, JFET-Based Digital Logic Gate Structure Using Resistive Level Shifters; High-Voltage-Input Level Translator Using Standard CMOS; Monitoring Digital Closed-Loop Feedback Systems; MASCOT - MATLAB Stability and Control Toolbox; MIRO Continuum Calibration for Asteroid Mode; GOATS Image Projection Component; Coded Modulation in C and MATLAB; Low-Dead-Volume Inlet for Vacuum Chamber; Thermal Control Method for High-Current Wire Bundles by Injecting a Thermally Conductive Filler; Method for Selective Cleaning of Mold Release from Composite Honeycomb Surfaces; Infrared-Bolometer Arrays with Reflective Backshorts; Commercialization of LARC (trade mark) -SI Polyimide Technology; Novel Low-Density Ablators Containing Hyperbranched Poly(azomethine)s; Carbon Nanotubes on Titanium Substrates for Stray Light Suppression; Monolithic, High-Speed Fiber-Optic Switching Array for Lidar; Grid-Tied Photovoltaic Power System; Spectroelectrochemical Instrument Measures TOC; A Miniaturized Video System for Monitoring Drosophila Behavior; Hydrofocusing Bioreactor Produces Anti-Cancer Alkaloids; Creep Measurement Video Extensometer; Radius of Curvature Measurement of Large Optics Using Interferometry and Laser Tracker n-B-pi-p Superlattice Infrared Detector; Safe Onboard Guidance and Control Under Probabilistic Uncertainty; General Tool for Evaluating High-Contrast Coronagraphic Telescope Performance Error Budgets; Hidden Statistics of Schroedinger Equation; Optimal Padding for the Two-Dimensional Fast Fourier Transform; Spatial Query for Planetary Data; Higher Order Mode Coupling in Feed Waveguide of a Planar Slot Array Antenna; Evolutionary Computational Methods for Identifying Emergent Behavior in Autonomous Systems; Sampling Theorem in Terms of the Bandwidth and Sampling Interval; Meteoroid/Orbital Debris Shield Engineering Development Practice and Procedure; Self-Balancing, Optical-Center-Pivot, Fast-Steering Mirror; Wireless Orbiter Hang-Angle Inclinometer System; and Internal Electrostatic Discharge Monitor - IESDM

Augmented reality device for first response scenarios

A prototype of a wearable computer system is proposed and implemented using commercial off-shelf components. The system is designed to allow the user to access location-specific information about an environment, and to provide capability for user tracking. Areas of applicability include primarily first response scenarios, with possible applications in maintenance or construction of buildings and other structures. Necessary preparation of the target environment prior to system\u27s deployment is limited to noninvasive labeling using optical fiducial markers. The system relies on computational vision methods for registration of labels and user position. With the system the user has access to on-demand information relevant to a particular real-world location. Team collaboration is assisted by user tracking and real-time visualizations of team member positions within the environment. The user interface and display methods are inspired by Augmented Reality1 (AR) techniques, incorporating a video-see-through Head Mounted Display (HMD) and fingerbending sensor glove.*. 1Augmented reality (AR) is a field of computer research which deals with the combination of real world and computer generated data. At present, most AR research is concerned with the use of live video imagery which is digitally processed and augmented by the addition of computer generated graphics. Advanced research includes the use of motion tracking data, fiducial marker recognition using machine vision, and the construction of controlled environments containing any number of sensors and actuators. (Source: Wikipedia) *This dissertation is a compound document (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Adobe Acrobat; Microsoft Office; Windows MediaPlayer or RealPlayer

Harnessing Microwave Photonics for Low Noise and Cryogenic Applications

In many cases, optical systems exhibit orders of magnitude improved performance over their microwave counterparts. For example, optical clocks have much better stability than microwave clocks, and generating picosecond pulses is easy in optics while it is very challenging with electronics. The field of microwave photonics aims to bring such advantages of optical systems to the microwave domain, achieving performance levels beyond the capabilities of conventional electronics. In the work presented here, we show how microwave photonics can be harnessed for low noise microwave generation and cryogenic applications. For low noise microwaves, focus is given to the behavior of photodiode flicker noise, the dominant noise contributor at long timescales, under short pulse illumination. Due to the cyclostationary nature of the noise process, flicker phase noise was found to be lower than flicker amplitude noise by as much as 10 dB, in agreement with our noise model. The cryogenic photonic link experiments were performed with the goal of driving Josephson junction arrays with photonically generated electrical pulse patterns, as required for producing AC voltage standards. This approach can potentially achieve system bandwidths as wide as 100 GHz, which is very difficult to achieve in cryogenic systems driven with traditional methods. With optically driven Josephson junctions, we synthesized a 1 kHz bipolar sine wave. An optical arbitrary pulse pattern generator based on a 2D line-by-line pulse shaper is also shown. The pulse shaper exhibits the highest resolution among programmable pulse shapers of similar designs. With these experiments, we show how microwave photonics can continue to push the state-of-the-art in low noise microwave generation and high-bandwidth signal generation in cryogenic environments.</p

VRCodes : embedding unobtrusive data for new devices in visible light

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 97-101).This thesis envisions a public space populated with active visible surfaces which appear different to a camera than to the human eye. Thus, they can act as general digital interfaces that transmit machine-compatible data as well as provide relative orientation without being obtrusive. We introduce a personal transceiver peripheral, and demonstrate this visual environment enables human participants to hear sound only from the location they are looking in, authenticate with proximal surfaces, and gather otherwise imperceptible data from an object in sight. We present a design methodology that assumes the availability of many independent and controllable light transmitters where each individual transmitter produces light at different color wavelengths. Today, controllable light transmitters take the form of digital billboards, signage and overhead lighting built for human use; light-capturing receivers take the form of mobile cameras and personal video camcorders. Following the software-defined approach, we leverage screens and cameras as parameterized hardware peripherals thus allowing flexibility and development of the proposed framework on general-purpose computers in a manner that is unobtrusive to humans. We develop VRCodes which display spatio-temporally modulated metamers on active screens thus conveying digital and positional information to a rolling-shutter camera; and physically-modified optical setups which encode data in a point-spread function thus exploiting the camera's wide-aperture. These techniques exploit how the camera sees something different from the human. We quantify the full potential of the system by characterizing basic bounds of a parameterized transceiver hardware along with the medium in which it operates. Evaluating performance highlights the underutilized temporal, spatial and frequency dimensions available to the interaction designer concerned with human perception. Results suggest that the one-way point-to-point transmission is good enough for extending the techniques toward a two-way bidrectional model with realizable hardware devices. The new visual environment contains a second data layer for machines that is synthetic and quantifiable; human interactions serve as the context.by Grace Woo.Ph.D

Data display programming

Computer programming for control of complex data processing operations involved in analysis and interpretation of large volumes of sensor data from scientific satellite