Floor Tile Energy Harvester for Self-Powered Wireless Occupancy Sensing

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Nathan Sharpes ◽  
Dušan Vučković ◽  
Shashank Priya

AbstractWe investigate a concept that can reduce the overall power requirement of a smart building through improvements in the real-time control of HVAC and indoor lighting based on the building occupancy. The increased number of embedded sensors necessary to realize the smart building concept results in a complex wiring and power structure. We demonstrate a floor tile energy harvester for creating a wireless and self-powered occupancy sensor. This sensor termed as “Smart Tile Energy Production Technology (STEP Tech)” can be used to control automation in smart buildings such as lighting and climate control based upon the real-time building occupancy mapping. The sensor comprises of piezoelectric transducer, energy harvesting circuit and wireless communication. Modeling and optimization procedure for the piezoelectric cymbal transducer is described within the framework of tiles. The design and selection of a packaging technique and construction of a durable floor tile enclosure aimed at protecting the bulk piezoceramic is discussed within the constraint that the deflection of the tile should be minimal such that it is not readily perceivable by humans, thus not disturbing their gait. Experimental results demonstrate that the piezoelectric tile could provide a promising solution for wireless occupancy sensing.

Author(s):  
Vladimir V. NEKRASOV

Developing a microcontroller-based system for controlling the flywheel motor of high-dynamics spacecraft using Russian-made parts and components made it possible to make statement of the problem of searching control function for a preset rotation rate of the flywheel rotor. This paper discusses one of the possible options for mathematical study of the stated problem, namely, application of structural analysis based on graph theory. Within the framework of the stated problem a graph was constructed for generating the new required rate, while in order to consider the stochastic case option the incidence and adjacency matrices were constructed. The stated problem was solved using a power matrix which transforms a set of contiguous matrices of the graph of admissible solution edge sequences, the real-time control function was found. Based on the results of this work, operational trials were run for the developed control function of the flywheel motor rotor rotation rate, a math model was constructed for the real-time control function, and conclusions were drawn about the feasibility of implementing the results of this study. Key words: Control function, graph, incidence matrix, adjacency matrix, power matrix, microcontroller control of the flywheel motor, highly dynamic spacecraft.


RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86490-86496 ◽  
Author(s):  
Tianqi Ma ◽  
Shaohui Guo ◽  
Zhihui Guo ◽  
Qiushi Zhu ◽  
Jinfu Chen

Indicated high pH benefits the accuracy of real-time control strategy, explained why DO as a control parameter is unreliable.


2000 ◽  
Vol 618 ◽  
Author(s):  
D.A. Gajewski ◽  
J.E. Guyer ◽  
J.J. Kopanski ◽  
J.G. Pellegrino

ABSTRACTWe present the real-time pseudodielectric function <ε(E)> of low-temperature-grown GaAs (LT-GaAs) thin films during the growth as a function of growth temperature Tg and thickness. We obtained accurate measurements of the real-time <εc(E)> by using in situspectroscopic ellipsometry (SE) in conjunction with active feedback control of the substrate temperature using diffuse reflectance spectroscopy. We show that for epitaxial LT-GaAs layers, the peak in the imaginary pseudodielectric function <ε2(E)> decreases in amplitude and sharpness systematically with decreasing Tg. We also revealed an abrupt change in <εc(E)> near the critical epitaxial thickness hepi, the value of which decreases with decreasing Tg. Above hepi, the LT-GaAs grows polycrystalline (amorphous) above (below) Tg ∼ 190°C. We also simultaneously monitored the surface roughness and crystallinity by using real-time reflection high-energy electron diffraction (RHEED). These results represent progress in obtaining real-time control over the composition and morphology of LT-GaAs


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