This Small Business Innovation Research (SBIR) Phase I project will develop a transformative green building technology that overcomes several limitations endemic to building automation systems in use today. Mainly, (a) the high cost of tethered sensor deployment, (b) the dependence on building energy, (c) the inaccuracy of occupancy sensors, and (d) the inability to adjust to changes in building usage over time. This project will utilize advanced wireless sensing technology to create a low-cost sensing platform that can be used to pervasively monitor building occupancy, environment, and energy consumption. These wireless sensors will then be embedded within a novel piezoelectric flooring system, which will provide power to the network using energy harvested from building foot traffic. By programming each wireless sensor with pattern classification capabilities, the resulting flooring system will be leveraged as an extremely accurate occupancy sensor. Lastly, by applying market-based optimization and reinforcement learning strategies, the resulting wireless smart floor itself will be designed to make optimal building control decisions in the midst of changing occupancy.
The broader impact/commercial potential of this project centers around the improved and reliable implementation of wireless sensing and energy harvesting technologies within the built environment. While these technological benefits can be applied to a wide range of societal problems, this project is focused on maximizing the environmental and economic impact of green building automation technology. In the United States, commercial buildings have been documented to consume upwards of 18% of the Nation?s total energy and 35% of the Nation?s electricity. This is due in large part to the inefficient use of energy (e.g., the lighting, heating or air conditioning of unoccupied spaces). It has been found that green building technologies like the those being developed in this project have the potential to reduce annual U.S. commercial building energy consumption by roughly 6%, mitigating the environmental consequences of wasted energy while creating a green building market that could grow to nearly $150 billion by 2013. This project aims to capitalize on the potential economic and environmental impact of green building technologies by providing a self-powered wireless smart flooring system that can minimize unnecessary energy expenditure while providing building occupants with an additional level of comfort and environmental control.
Introduction Roughly 35% of electricity consumption in the United States takes place within commercial buildings, and is due in large part to the inefficient use of energy. As such, green building automation (GBA) systems (consisting of networked sensing and building control technologies) have emerged in recent years to monitor environmental conditions and to intelligently control energy expenditure so as to minimize waste. Unfortunately, current GBA systems are often expensive to install, require a significant amount of energy to function, and suffer from inefficient occupancy detection technologies. In this NSF SBIR Phase I/IB project, a transformative GBA solution that overcomes these technology bottlenecks is being developed. This solution will allow the environmental and economic impacts of GBA to be fully realized through the following technological advances: A novel flooring system will harvest available kinetic energy from building foot traffic in order to provide power to a dense network of low-cost intelligent wireless sensing nodes. This wireless sensor network will accurately detect and quantify building occupancy. This wireless sensor network will learn (and re-learn) the energy usage trends and environmental preferences associated with a given space. This wireless sensor network will optimally control building systems while discriminating between energy savings and environmental preferences. In whole, this system provides (a) affordable sensing capabilities that are pervasive, self-powered, and low-maintenance, as well as (b) modular, retrofitable, and affordable control technologies that can adjust over time to changes in building occupancy or energy usage. As such, the proposed solution represents a modular, low-cost, zero-energy GBA system. Energy-Harvesting Flooring System During the NSF SBIR Phase I/IB timeline, Civionics partnered with POWERleap, Inc. to investigate the development of a novel energy harvesting flooring system, built around a new breed of piezoelectric generators and harvesting circuitry designed to capture kinetic energy from the vibrations and mechanical stresses inherent to everyday pedestrian activity. This type of flooring can provide the energy required to accurately sense occupancy and environmental conditions throughout a commercial building and communicate that information wirelessly. This collaboration resulted in a mechanical framing design for a flooring tile that centers on a Macro Fiber Composite (MFC) energy harvester. This harvester is a piezoelectric device comprised of an array of fibers cast in a mylar-like sandwich that creates a uniquely flexible and durable device with high current output. Based on a simple tension assembly concept, the developed piezoelectric flooring tile has a low profile of less than one inch (1") in height, and can generate roughly 0.5-1.0J per footstep. Intelligent Wireless Sensing Nodes During the NSF SBIR Phase I/IB timeline, Civionics developed their own proprietary wireless sensing node for modular and low-cost building sub-metering and automation. This platform can be powered by the aforementioned piezoelectric flooring tile, and it features a suite of on-board sensing capabilities (temperature, humidity, and tri-axial acceleration). While the advantages of this self-powered wireless sensing node in a distributed wireless GBA system are evident, an additional wireless device was designed to (a) receive communication packets from flooring tiles located throughout a building, (b) provide periodic always-on sensing data, and (c) command lights and other GBA system components based on occupancy, environmental, and energy consumption data. This second design features improved data processing and data storage capabilities, an output port for controlling GBA components, and an input port for easy connection to external sensing transducers and actuators. State-of-the-Art Occupancy Sensing After finishing work on the hardware described above, Civionics began to investigate the ability of the developed architecture to accurately detect, quantify, and track occupants within a commercial building environment. It was found that flooring tile acceleration and piezoelectric voltage output, when used in tandem, can be powerful indicators of what type of activity is taking place within a commercial building environment. Commercial and Retail Testbeds During the NSF SBIR Phase IB timeline, Civionics explored the commercial viability of the developed technology through application to the retail environment. Specifically, we worked with POWERleap, Gillette, and Channel Technologies Group to create two pilot installations that were designed to (a) prove to the retail market the value of an energy-saving flooring system, (b) demonstrate the ability of the system to turn on and off accent lighting and track occupancy patterns, (c) evaluate the systemâ€™s ability to target advertising based on store occupancy, and (d) provide Civionics with two testbeds for further development of their wireless GBA technologies.