UC Berkeleys Demand Response Project: Including Self Powered Nodes for measuring temperatures in Sma

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UC Berkeleys Demand Response
ProjectIncluding Self Powered Nodes for
measuring temperatures in Smart/Responsive
Buildings

• Paul Wright, Eric Carleton, Dan Steingart, Nate
  Ota, Beth Reilly, Jessy Baker, Elaine Lai, Eli
  Leland
• In collaboration with the multidisciplinary team
  ofEdward Arens Charlie Huizenga (Buildings),
• David Auslander (Controls), David Culler (O/S),
  Jan Rabaey (Radios), Richard White (Sensors)

January 12th 2005 Monterey
Funded by the California Energy Commission (CEC)
PZT
W
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Impact of MicroPower on CA MacroPower
Crisis

• Goals include Reduce blackouts at peak usage
  times
• Enabling Technology Development Key to research
  approach
• Meters, thermostats, temperature-nodes In ad hoc
  self organizing wireless networks (low power
  radios, energy scavenging 450 µW, TinyOS)
• Cheaper better faster for a 10x10x10 mission
• Residential focus in CA and affordable for even
  the smallest homes
• One working scenario to demonstrate new
  technologies
• Receives price signals every 15 mins (emergency
  signals treated immediately)
• Users provide preferences to their thermostat
  and major appliances, thru easy to use GUIs,
  acting as the users proxy
• Eventually -- self-learning systems
• Time stamped usage sent back once a day -- say
  at 3am -- Or in an emergency the response would
  be immediate

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Vision/Summary 1.
New Thermostat (and/or TouchPad) shows /kWhr
every 15mins expected monthly bill. Automatic
adjustment of HVAC cost/comfort. Appliance nodes
glow red2. New Meter conveys usage/charge back
to supplier every 24 hours3. TempNodes in every
room of house allow for fine grained
comfort/control
Incoming price signalsto Thermostat Display
Appliance lights show price level appliances
powered-down
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Vision Integrate these four Enabling
Technologies for a 10x10x10 mission

• 1. Controls applications on a prototype of New
  Thermostat
• Easy-to-use thermostat that can act as an
  automatic proxy to optimize energy savings versus
  comfort under varying energy price conditions.
• 2. Voltage/Current Sensors and relation to New
  Meter
• Low-cost wireless, passive and non-intrusive
  current and voltage sensing for application to
  the next generation meter and other devices.
• 3. Pico Radio TinyOS for networking of devices
• Low-power and low-cost radio platforms, supported
  by appropriate operating systems, for ad hoc
  sensor and actuator network applications.
• 4. Energy Scavenging (important for Temp Nodes)
• Infinite life power source that scavenges energy
  from the environment. Possible energy sources
  include solar, vibration, air flow, and
  hybrid.

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Topic 1 Controls/Thermostat

• Challenges
• Interface thats easy to understand and intuitive
  -- for many sectors of society.
• Learning algorithms that will optimize energy
  savings and comfort with time-varying energy
  prices (e.g. pre-cooling algorithms)
• Display to the user the expected monthly bill
  (shock effect of monthly credit-card-bill)
• Control strategies for a house that can react to
  the possibility of low in-house network quality
  or complete network failure.

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Wireless Controlled Outlets
Wireless nodeinside the box controls latching
relay, turning lamp at right on or off. Or,
Remote control can communicate with node.
Yellow plug body contains AC/DC converter driving
node shown with lighted red LED.
Appliance Traffic Light
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Demo inFull-scale Testbed
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Topic 2 Sensor Measurements applicable to New
Meter other devices

• Needs
• AC current sensing (see next slide)
• AC voltage sensing
• Specifications
• Wireless data transmission of home-usage
• No external power source required
• Proximity coupling for inexpensive installation

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MEMS current sensor (prototype)

• Electric current (magnetic field) measurement
  techniques
• Inductor
• Hall effect
• GMR sensor
• Magnetic force on MEMS sensor

Magnetic material on MEMS canti-lever


120 Hz
120 Hz
output signal
output signal
I
I
I
I
MEMS cantilever withpiezoelectric film
out
in
out
in
60 Hz
60 Hz

AC current
AC current

AC current sets up time-varying magnetic field
whose gradient exerts force on high-permeability
magnetic material at end of MEMS cantilever
resonator, which vibrates and generates
piezoelectric output voltage
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Topic 3 Core Technology Platforms Radios
TinyOS
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Mesh-networked devices Example/Possible Testbed
topology
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Topic 4 Energy Scavenging Critical Enabling
Technology to achieve No replaceable batteries
on the nodes

• Possibilities include-
• Photovoltaic (Solar)
• Vibrations
• Air Flow
• Temperature Gradients
• Pressure Gradients
• Human Power
• MIT shoe-insert project
• FreePlay wind-up products

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Vibration-Based-Scavenging Impact of
MicroPower on CA GigaPower Challenges

• Sources
• HVAC ducts
• Raised Floors
• Motors
• Large windows
• Mount under wooden staircase

• Three Rules for Design
• P M
• P A2
• P 1/?
• PZT-shims with W-mass
• Early work 800 µW/cm3 at 5 m/s2 (on a clothes
  dryer!)
• Recent successes
• TinyTemp Node on stairs
• MEMS piezo bender

W
PZT
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DESIGN FLOW
Frequency and Acceleration of Source
1a
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Geometry, materials
Elastic coefficient
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Electric Signal
Power
Stiffness Model
New elastic coefficient and coupling coefficient
Generator Equation
Load/Power Circuit
Preload Effects
1b
Geometry, materials
Coupling coefficient
Coupling Model
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Modeling Summary of Outcome

• Find a source with a significant A2/? ratio
• Intermittent sources are acceptable, and
  continuous vibration sources are ideal
• -HVAC, refrigerators,
• -peaks at 60/120 Hz

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Residential Vibration Sources
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In-progress tunable- resonance device design

• Bracket fashioned from machined aluminum
• Load is applied by a setscrew assembly
• Proof mass is mounted using a tiny screw
• Resonance range can be adjusted by changing proof
  mass or shim thickness
• Proof mass 15 grams
• Piezo shim 32 mm x 13 mm x 0.5 mm
• Unloaded resonance 150 Hz

Proof mass 15 grams Piezo shim 32 mm x 13 mm
x 0.5 mm Unloaded resonance 150 Hz
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Schematic vs.
Actual Device
View from above of MEMS cantilevers
End-on view of one MEMS cantilever
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Potential Breakthroughs The PicoCube
Thermistor

• Early thinking about integrated device 1 cm3
• 3-D wiring
• 4 sides with solar panels
• 2 sides with sensors
• On-board recharg. battery
• On-board piezo electric generation

Photoresistor
Solar Panels
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Step One

• 3 Separate Components
• 1 Bus
• Overall
• Modular Design
• Simplifies Connection
• Steals a surface
• Component packing eats significant space

Power Bus
Microbattery
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Smart Dust powered by Free EnergyforSmart
Buildings and Intelligent Manufacturing
End/Summary/Questions

Temp.
Light sensor
Todays prototype
2007
2006
2005
W
1cm
PZT
MEMS version inprogress for 2007
2 inch