Transcript Slide 1

Conference Room Monitoring System
Group Members: Michael Benoit & Michael Swavola
University of
Pennsylvania
April 21, 2005
Advisor: Dr. Insup Lee
Abstract
Lighting Control
Since 2002, much research has been done across the country in the area
of micro-electric mechanical systems as a potential solution to the
pandemic problem of inefficient energy consumption. The team has built
upon the feasibility research done at Berkeley and MIT to design and
develop an intelligent environment control scheme with the hope of
significantly reducing energy consumption in conference rooms.
The X10 technology used in this project has been around for a number of years and is a cost-effective
way to provide safe remote control of 110 VAC lamps and appliances from a PC. The basic X10 control
module is placed into a standard home 110 VAC wall outlet. The item to be controlled, a lamp or
appliance, in turn, is plugged into the X10 module. The control module awaits commands from the X10
transceiver, also plugged into a 110 VAC wall outlet. These commands are sent over 110 VAC wires in
digital format to a specific control module.
The objective of the project is to integrate three stand-alone components
into one adaptive environment control system. The components are
location detection, environment sensing, and output control.
The X10 modules have an addressing scheme consisting of a letter and a number. Each control module
has two rotary switches so a unique address can be set for a specific module controlling a specific lamp
or appliance. In this way one transceiver can communicate to up to 16 individual control modules. Up to
16 transceivers can be in the same system giving a total capability of up to 256 control points.
The team is attacking the problem by designing independent location
and environment sensing systems and connecting them. Each sensing
system is isolated to a group of “motes” dedicated to that application.
The data collected is compiled and passed synchronously through a
resilient “shortest-hop” data transmission scheme. The required outputs
are then computed and sent via the shortest-route to the mote
environment outputs. Error is controlled by redundancy checks between
mote sensors, and is measured by comparing sensor readings within
each group to lighting output.
The X10 transceiver receives its commands from a serial interface that plugs into the 9-pin serial port on
a PC and sends commands to the X10 transceiver over wireless RF. In this way the computer can safely
control 110 VAC without having any high-power lines directly connected to it. We used an X10 driver
known as BottleRocket to control the FireCracker kit. BottleRocket is a command-line interface for Unix
systems which can be called from scripts and linked into other programs.
Software Hierarchy
The final result is an integrated system which uses Passive Infrared
sensors to accurately detect room entrance and exit, basic light sensors
distributed across the network to provide accurate environment
monitoring, and a low-error, low-power transmission and output system
that adjusts room lighting.
Previous Work
PIR Detection
The field of distributed wireless sensor networks (WSN) has grown
substantially over the last decade. Largely through continued academic
efforts, WSN’s have grown from slow proofs of concept to vehicles for
commercial application. The widely recognized leaders in WSN, or “mote
network” development, have been MIT’s Lincoln Lab and Berkeley’s BEST
Lab, both of which have been supported by substantial monetary
investments from the Department of Defense (Dust Networks, 2004).
The application of mote networks to the area of “intelligent energy” began
with BEST Lab’s web-publication of its highly regarded TinyOS operating
system in 2000. Since that time developers around the world have
adopted TinyOS as the standard for mote development due to its use of
object-oriented nesC and seamless Java language integration. The
applications for WSN’s have grown with the operating system, ranging
from flexible perimeter detection to embedded earthquake monitoring,
ivy-like ad-hoc networking to wildfire surveillance, but all of these
applications rely on the motes’ ability to read and forward data, and
localize each other. A flexible feedback system for efficient energy use
has been a target from the start. Current WSN environment control
projects include:
Wireless Lighting System
Under floor Air Distribution and Quality Control
Acoustic Satisfaction Analysis
1
Base Mote
2
8
3
7
4
1. PIR software collects data and sends average sensor readings to the base
2. The base mote collects data averages from the PIR and light-sensing motes. Messages are
distinguished by group ID numbers as well as mote ID number. Dim and brighten messages are
passed to the serial forwarder according to photo readings. On/off messages are determined by
the PIR readings.
3. The serial forwarder receives incoming packets and converts them to TCP/IP packets to allow
other programs to interact with the sensor network. The serial forwarder does not display the
packet data itself, but rather updates the packet counters. Once running, the serial forwarder
listens for network client connections on a given TCP port (9001 is the default), and simply
forwards messages from the serial port to the network client connection, and vice versa. In this
case, messages are passed to the BottleRocket driver to execute the appropriate commands
and are returned to the serial forwarder to be sent back through the serial port.
4. The serial port is connected to the CM17A serial adapter for the X10 FireCracker kit which then
transmits a command to the X10 transceiver.
5. The X10 transceiver sends the command across the 110VAC wires in digital format to the X10
Lamp Module where the lamp either brightens or dims.
6. The photo sensor on the light-sensing mote collects light output readings.
7. The light-sensing mote transmits its data to the base.
8. The PIR transmits an alarm message to the light-sensing mote indicating that it should collect
data.
Group ID
0
1
2
BottleRocket Driver
5
X10 Transceiver
Mote Group
Base
PIR
Photo
6
X10 Lamp Module
Light Sensing Mote
The Mica2 and Mica2dot
intelligent radio modules
The MTS310CA sensor
board for the Mica2