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Andrew C. Waterbury

Bio: Andrew C. Waterbury is an academic researcher from University of California, Berkeley. The author has contributed to research in topics: Condition monitoring & Energy harvesting. The author has an hindex of 4, co-authored 7 publications receiving 245 citations.

Papers
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Proceedings ArticleDOI
21 May 2007
TL;DR: The goal of the work is to focus on health-related applications of wireless sensor networks and how current (and future) technologies will enable automated home health monitoring.
Abstract: Sophisticated electronics are within reach of average users. Cooperation between wireless sensor networks and existing consumer electronic infrastructures can assist in the areas of health care and patient monitoring. This will improve the quality of life of patients, provide early detection for certain ailments, and improve doctor-patient efficiency. The goal of our work is to focus on health-related applications of wireless sensor networks. In this paper we detail our experiences building several prototypes and discuss the driving force behind home health monitoring and how current (and future) technologies will enable automated home health monitoring.

200 citations

Journal ArticleDOI
01 Jun 2013
TL;DR: In this paper, a small mechanical vibration energy harvester using electromagnetic transduction was constructed and used to harvest vibrations from large industrial pump motors and machine tools, and it was shown that rapid jog events could be harvested.
Abstract: To enable self-sustaining long-lasting wireless condition monitoring sensors, a small mechanical vibration energy harvester using electromagnetic transduction was constructed and used to harvest vibrations from large industrial pump motors and machine tool. The prototype harvester was roughly the size of a cube with 2.5cm long sides. Power ranging from 0.2 to 1.5mW was harvested from 15 to 30kW water pump motors. For a machine tool, metal cutting vibrations and rapid jog events were explored as possible harvestable sources of energy. Power ranging from 0.9 to 1.9mW was harvested during facemilling operations, and it was shown that rapid jog events could be harvested. The power levels harvested from the pump motors and machine tools are sufficient to provide the time-averaged power requirements of commercial wireless sensor nodes, enabling sensor nodes to overcome the finite life of replaceable batteries.

35 citations

Journal ArticleDOI
01 Jun 2014
TL;DR: In this paper, a design methodology for electronic systems powered by energy harvesting is proposed, and a test case is presented in which the vibrations of an electromagnetic device are harvested, converted, and used to power a wireless sensor node.
Abstract: Abstract A design methodology is proposed for electronic systems powered by energy harvesting. The methodology first considers the operating environment. It then evaluates the supply-side (the attributes of the harvester), the demand-side (the engineering application or load which receives and uses the converted power), and the power conditioning needed between supply and demand. A test case is presented in which the vibrations of an electromagnetic device are harvested, converted, and used to power a wireless sensor node. Such a node is being used for the condition based monitoring of manufacturing equipment.

10 citations

01 Jan 2012
TL;DR: In this article, the authors present theoretical analysis and experimental results of a device called a Piezoelectrodynamic Gyrator (PEDG) for low-frequency wireless power transfer (WPT) and AC energy harvesting.
Abstract: We present theoretical analysis and experimental results of a device we call a Piezoelectrodynamic Gyrator (PED­G) , and discuss its applications to low-frequency wireless power transfer (WPT) and AC energy harvesting. A PED-G utilizes a resonating mechanical spring-mass system (receiver) containing a permanent magnet as its proof mass, which is excited to resonance by a sinusoidal magnetic field generated by a nearby coil (transmitter) on the primary side. The mechanical energy in the resonating spring-mass system is then extracted through a piezoelectric coupling to an electric circuit on the secondary side. We present experimental results of two PED-G prototypes. Electromechanical resonance enables WPT applications at frequencies orders of magnitude lower than that of purely inductively coupled WPT.

5 citations

01 Jan 2011
TL;DR: In this article, the authors investigated the possibility of using a small amount of electrical energy to power condition monitoring sensors in manufacturing and industrial environments. But, the authors did not specify the power requirements for the harvester designs.
Abstract: Embedded condition monitoring sensors that eliminate unanticipated failures of critical or high value equipment improve asset utilization while streamlining maintenance and support operations. General Electric and Rolls Royce use embedded sensors on their jet engines that have eliminated failures and allowed maintenance to be performed on an as-needed basis. As a result, airplane utilization increases while enabling the consolidation of maintenance operations. In more traditional industrial settings, condition monitoring of manufacturing and industrial equipment can quickly impact bottom lines through improved productivity and streamlined operations in ways comparable to what is already being realized in the aviation industry.Wireless sensor nodes provide embedded sensing with little overhead or infrastructure cost as long as appropriate power sources are available to sustain the node over its target lifetime. Energy is the limiting factor for sensor node lifetimes and data streams. Since most manufacturing and industrial equipment have some associated vibration spectrum when operating, transducing the mechanical energy of vibrations to a small amount of electrical energy electromagnetically was explored as a way of powering condition monitoring sensors. Large pump motors and a machine tool were surveyed to characterize input vibration accelerations associated with manufacturing and industrial operations. Harvestable acceleration peaks occurred below 120 Hz and had magnitudes near or less than 0.1 g. Metal cutting vibrations were characterized and shown to have vibration frequencies proportional to the number of cutting teeth and the spindle RPM. It was also shown that, the 0.4-1.0 g acceleration impulses associated with the rapid axis motion of a machine tool are harvestable. Simple magnet and coil as well as coreless electromagnetic architectures were pursued using an overall device size constrain of a cube with 2.5 cm sides. That device size was roughly the same as a c-cell battery that is capable of powering a wireless sensor node for five to ten years. The target power for the harvester designs was the time-averaged powers of hundreds of microwatts to single milliwatts required by commercial wireless sensor nodes. Prototype vibration harvesters based on magnet-coil and voice-coil transducer designs were fabricated and evaluated. Both were able to produce about a milliwatt on a vibration platform for an input acceleration amplitude of 0.1 g at frequencies consistent with those characterized on the pump motors and machine tool. The power densities of the unoptomized proof of concept prototypes were comparable to commercial vibration harvester but at less than one seventh the size. The voice-coil prototype was installed on several 15-30 kW pump motors running support systems for a microfabrication lab, and unrectified powers of 0.2¬-1.5 mW were harvested. Similarly, 0.8-1.8 mW was harvested from metal cutting vibrations while facemilling cast iron and stainless steel, showing that powers comparable to commercial sense node requirements could be harvested from industrial settings. Coreless motor architectures proved to be best suited for industrial settings because the unconstrained magnetic flux of simple magnet-coil designs interacted with the iron and steel mounting surfaces commonly found on large machines. Simulated coreless magnetic circuit designs showed that gap magnetic flux densities approaching one tesla could be possible but were not implemented.

4 citations


Cited by
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Journal ArticleDOI
TL;DR: This survey presents a comprehensive review of the recent literature since the publication of a survey on sensor networks, and gives an overview of several new applications and then reviews the literature on various aspects of WSNs.

5,626 citations

Journal ArticleDOI
TL;DR: This paper provides several state of the art examples together with the design considerations like unobtrusiveness, scalability, energy efficiency, security and also provides a comprehensive analysis of the benefits and challenges of these systems.

1,331 citations

Journal ArticleDOI
TL;DR: This paper provides a detailed investigation of sensor devices, physical layer, data link layer, and radio technology aspects of BAN research, and presents a taxonomy of B Ban projects that have been introduced/proposed to date.
Abstract: Advances in wireless communication technologies, such as wearable and implantable biosensors, along with recent developments in the embedded computing area are enabling the design, development, and implementation of body area networks. This class of networks is paving the way for the deployment of innovative healthcare monitoring applications. In the past few years, much of the research in the area of body area networks has focused on issues related to wireless sensor designs, sensor miniaturization, low-power sensor circuitry, signal processing, and communications protocols. In this paper, we present an overview of body area networks, and a discussion of BAN communications types and their related issues. We provide a detailed investigation of sensor devices, physical layer, data link layer, and radio technology aspects of BAN research. We also present a taxonomy of BAN projects that have been introduced/proposed to date. Finally, we highlight some of the design challenges and open issues that still need to be addressed to make BANs truly ubiquitous for a wide range of applications.

1,239 citations

Journal ArticleDOI
26 May 2011-Sensors
TL;DR: The important role of body sensor networks in medicine to minimize the need for caregivers and help the chronically ill and elderly people live an independent life, besides providing people with quality care is explained.
Abstract: Wireless sensor network (WSN) technologies are considered one of the key research areas in computer science and the healthcare application industries for improving the quality of life. The purpose of this paper is to provide a snapshot of current developments and future direction of research on wearable and implantable body area network systems for continuous monitoring of patients. This paper explains the important role of body sensor networks in medicine to minimize the need for caregivers and help the chronically ill and elderly people live an independent life, besides providing people with quality care. The paper provides several examples of state of the art technology together with the design considerations like unobtrusiveness, scalability, energy efficiency, security and also provides a comprehensive analysis of the various benefits and drawbacks of these systems. Although offering significant benefits, the field of wearable and implantable body sensor networks still faces major challenges and open research problems which are investigated and covered, along with some proposed solutions, in this paper.

461 citations

Proceedings ArticleDOI
26 Oct 2011
TL;DR: This investigation takes the move by decomposing the storyline of a day in Robert's life, the authors' unlucky character in the not so far future, into simple processes and their interactions, and devise the main communication requirements for those processes and for their integration in the Internet as web services.
Abstract: This paper proposes the Internet of Things communication framework as the main enabler for distributed worldwide health care applications. Starting from the recent availability of wireless medical sensor prototypes and the growing diffusion of electronic health care record databases, we analyze the requirements of a unified communication framework. Our investigation takes the move by decomposing the storyline of a day in Robert's life, our unlucky character in the not so far future, into simple processes and their interactions. Subsequently, we devise the main communication requirements for those processes and for their integration in the Internet as web services. Finally, we present the Internet of Things protocol stack and the advantages it brings to health care scenarios in terms of the identified requirements.

251 citations