Measuring 3D indoor air velocity via an inexpensive low-power ultrasonic anemometer

The ability to inexpensively monitor indoor air speed and direction on a continuous basis would transform the control of environmental quality and energy use in buildings. Air motion transports energy, ventilation air, and pollutants around building interiors and their occupants, and measured feedback about it could be used in numerous ways to improve building operation. However indoor air movement is rarely monitored because of the expense and fragility of sensors. This paper describes a unique anemometer developed by the authors, that measures 3-dimensional air velocity for indoor environmental applications, leveraging new microelectromechanical systems (MEMS) technology for ultrasonic range-finding. The anemometer uses a tetrahedral arrangement of four transceivers, the smallest number able to capture a 3-dimensional flow, that provides greater measurement redundancy than in existing anemometry. We describe the theory, hardware, and software of the anemometer, including algorithms that detect and eliminate shielding errors caused by the wakes from anemometer support struts. The anemometer has a resolution and starting threshold of 0.01 m/s, an absolute air speed error of 0.05 m/s at a given orientation with minimal filtering, 3.1° angle- and 0.11 m/s velocity errors over 360° azimuthal rotation, and 3.5° angle- and 0.07 m/s velocity errors over 135° vertical declination. It includes radio connection to internet and is able to operate standalone for multiple years on a standard battery. The anemometer also measures temperature and has a compass and tilt sensor so that flow direction is globally referenced regardless of anemometer orientation. The retail cost of parts is $100 USD, and all parts snap together for ease of assembly

Multi-rotor unmanned aerial vehicles (UVAs) and high-resolution compact digital cameras: a promising new method for monitoring changes to surface karst resources

In the course of doctoral research, the authors required a quick and accurate means of documenting the real-time state of surface karst features at a variety of scales in remote and challenging field conditions. The main difficulty was finding an aerial platform that was 1) consistently effective; 2) versatile; and 3) relatively inexpensive. High resolution vertical images obtained during recreational use of a small multi-rotor unmanned aerial vehicle (UAV) seemed to have the potential to answer this need. Using five case studies, the authors examine the potential of these images for mapping, documenting, and monitoring changes to surface karst resources following forestry-related activities in the coastal temperate rainforest of British Columbia (B.C.). Possible applications, strengths and limitations of this technology are discussed. The authors conclude that mini quadcopter UAVs equipped with high-resolution compact digital cameras are a promising and cost-effective new tool for karst scientists and karst managers

DEVELOPMENT OF AN UNMANNED AERIAL VEHICLE FOR LOW-COST REMOTE SENSING AND AERIAL PHOTOGRAPHY

The paper describes major features of an unmanned aerial vehicle, designed undersafety and performance requirements for missions of aerial photography and remotesensing in precision agriculture. Unmanned aerial vehicles have vast potential asobservation and data gathering platforms for a wide variety of applications. The goalof the project was to develop a small, low cost, electrically powered, unmanned aerialvehicle designed in conjunction with a payload of imaging equipment to obtainremote sensing images of agricultural fields. The results indicate that this conceptwas feasible in obtaining high quality aerial images

Micro Sensor Node for Air Pollutant Monitoring: Hardware and Software Issues

Wireless sensor networks equipped with various gas sensors have been actively used for air quality monitoring. Previous studies have typically explored system issues that include middleware or networking performance, but most research has barely considered the details of the hardware and software of the sensor node itself. In this paper, we focus on the design and implementation of a sensor board for air pollutant monitoring applications. Several hardware and software issues are discussed to explore the possibilities of a practical WSN-based air pollution monitoring system. Through extensive experiments and evaluation, we have determined the various characteristics of the gas sensors and their practical implications for air pollutant monitoring systems

Designing and Implementing Future Aerial Communication Networks

Providing "connectivity from the sky" is the new innovative trend in wireless communications. High and low altitude platforms, drones, aircrafts and airships are being considered as the candidates for deploying wireless communications complementing the terrestrial communication infrastructure. In this article, we report the detailed account of the design and implementation challenges of an aerial network consisting of LTE Advanced (LTE-A) base stations. In particular, we review achievements and innovations harnessed by an aerial network composed of Helikite platforms. Helikites can be raised in the sky to bring Internet access during special events and in the aftermath of an emergency. The trial phase of the system mounting LTE-A technology onboard Helikites to serve users on the ground showed not only to be very encouraging but that such a system could offer even a longer lasting solution provided that inefficiency in powering the radio frequency equipment in the Helikite can be overcome.Comment: IEEE Communications Magazine 201

PHALANX: Expendable Projectile Sensor Networks for Planetary Exploration

Technologies enabling long-term, wide-ranging measurement in hard-to-reach areas are a critical need for planetary science inquiry. Phenomena of interest include flows or variations in volatiles, gas composition or concentration, particulate density, or even simply temperature. Improved measurement of these processes enables understanding of exotic geologies and distributions or correlating indicators of trapped water or biological activity. However, such data is often needed in unsafe areas such as caves, lava tubes, or steep ravines not easily reached by current spacecraft and planetary robots. To address this capability gap, we have developed miniaturized, expendable sensors which can be ballistically lobbed from a robotic rover or static lander - or even dropped during a flyover. These projectiles can perform sensing during flight and after anchoring to terrain features. By augmenting exploration systems with these sensors, we can extend situational awareness, perform long-duration monitoring, and reduce utilization of primary mobility resources, all of which are crucial in surface missions. We call the integrated payload that includes a cold gas launcher, smart projectiles, planning software, network discovery, and science sensing: PHALANX. In this paper, we introduce the mission architecture for PHALANX and describe an exploration concept that pairs projectile sensors with a rover mothership. Science use cases explored include reconnaissance using ballistic cameras, volatiles detection, and building timelapse maps of temperature and illumination conditions. Strategies to autonomously coordinate constellations of deployed sensors to self-discover and localize with peer ranging (i.e. a local GPS) are summarized, thus providing communications infrastructure beyond-line-of-sight (BLOS) of the rover. Capabilities were demonstrated through both simulation and physical testing with a terrestrial prototype. The approach to developing a terrestrial prototype is discussed, including design of the launching mechanism, projectile optimization, micro-electronics fabrication, and sensor selection. Results from early testing and characterization of commercial-off-the-shelf (COTS) components are reported. Nodes were subjected to successful burn-in tests over 48 hours at full logging duty cycle. Integrated field tests were conducted in the Roverscape, a half-acre planetary analog environment at NASA Ames, where we tested up to 10 sensor nodes simultaneously coordinating with an exploration rover. Ranging accuracy has been demonstrated to be within +/-10cm over 20m using commodity radios when compared to high-resolution laser scanner ground truthing. Evolution of the design, including progressive miniaturization of the electronics and iterated modifications of the enclosure housing for streamlining and optimized radio performance are described. Finally, lessons learned to date, gaps toward eventual flight mission implementation, and continuing future development plans are discussed

A Mobile Self-Leveling Landing Platform for Small-Scale UAVs

This thesis presents a semi-autonomous mobile self-leveling landing platform designed to launch, recover and re-launch VTOL UAVs without the need for human intervention. The landing platform is rugged, lightweight and inexpensive, making it ideal for civilian applications that require a base station from which a rotorcraft UAV can be launched and recovered on terrain that is normally unsuitable for UAV operations. This landing platform is capable of self-leveling on rough terrain and inclined slopes, and can autonomously operate in remote locations for extended periods of time using large onboard lithium batteries and wireless communication. This thesis discusses the unique design aspects of this landing platform that set it apart from similar systems, describes the prototype vehicle, and shows experimental results to demonstrate the system is fully functional and meets all the primary design requirement

Development of a Self-diagnostic System for Photovoltaic based Highway Signage Boards and Warning Devices

Federal highways and state roads in Malaysia are sites of most traffic accidents. One contributing factor is the lack of or low visibility of road signage at dangerous bends or road corners. It is very important to have safety warning signage at strategic locations to warn drivers on conditions or hazards ahead by cautioning maximum allowable vehicle speed limit. However, signage boards alone by themselves are not enough. The relevant authorities have started to add flashing beacons to enhance visibility, but the availability of on-grid power supply often hinders their installation. This is now a non-issue with the advent of solar power. As and when more signage with flashing beacons are installed; scattered over a wide area, there is an operational need to monitor their performance status remotely for timely effective maintenance and repair

Creating a Portable Wireless Display

Real time computing has become a vital part in military applications. Moreover certain operations require that the soldiers carry computing devices to assist them. These devices, besides providing them with location-based information, should also be transmitting the requested data. In this thesis, we present a portable wireless display prototype, which renders the desktop of a remote computer. The prototype functions under the range of an 802.11b or Bluetooth wireless network. The Software interfacing is done with Virtual Network Computing (VNC). This thesis is a first step towards analyzing and creating head/wrist mounted displays capable of transmitting images from a remote computer. The thesis starts with an overview and proceeds with a discussion on the concepts involved behind the functioning of the prototype. It then provides a detailed description of the how the prototype was built, followed by a performance test and its analysis and concludes by summarizing the results achieved