Note: Descriptions are shown in the official language in which they were submitted.
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
SYSTEM AND METHOD FOR DISTRIBUTED MONITORING USING
REMOTE SENSORS
This application claims the benefit of U.S. Provisional Patent Application
Serial
No. 60/199,346, filed April 25, 2000, the entire disclosure of which is
incorporated herein
by reference. This application is related to U.S. Provisional Patent
Application Serial No.
60/199,347, filed April 25, 2000, and to U.S. Patent Application No.
09/421,399, filed
October 21, 1999, the entire disclosures of which are incorporated herein by
reference.
This application includes material which is subject to copyright protection.
The
copyright owner has no objection to the facsimile reproduction by anyone of
the patent
disclosure, as it appears in the Patent and Trademark Office files or records,
but
otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates in general to distributed monitoring of remote sensors,
and
in particular to novel systems which are useful for remote monitoring of
chemical
properties or electric current.
2. Related Art
Over the last three decades the United States has spent billions of dollars
trying to
2o monitor and clean up contaminated ground water and soils as a result of a
period in which
the industrial expansion of our Nation outpaced our knowledge of safe chemical
disposal.
Despite large sums of financial investment to protect and recover natural
resources,
scientists continue to struggle to accurately monitor ground water and detect
contaminants, or quantify the effect of contaminants on the ecosystem as a
whole. This
struggle is due to two primary reasons: 1) there is a lack of advanced, field
deployable,
environmental sensory systems capable of continuous, long-term monitoring of
physical,
chemical, and biological measurands, and 2) there are major problems
associated with
biofouling of the sensors due to nutrient overloading and algae growth.
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
The presence of chemicals and complex molecules determines the health of a
water source in relation to the ecosystem as a whole, and is typically
classified into two
groups: primary and secondary contaminants. The former group, which includes
heavy
metals, radionucliotides, and dioxins, is often characterized as those
contaminants that are
stable in nature and resist breakdown due to sunlight or temperature, or do
not dissolve
easily into a water system. These primary contaminants often lead to localized
hot spots
within an ecosystem, resulting in complete devastation of the normal localized
aquatic
balance in addition to becoming a point source for continuous contamination
for decades
to come. By contrast, the latter group is known as the effect group, and is
characterized
1o by the overall change in traditional water quality monitoring parameters
which include
dissolved oxygen (DO), pH, dissolved solids, nitrate-nitrite nitrogen (NNN),
and total
phosphorous (TP).
Historically, monitoring of contaminants or their effects has been done
through
discrete sampling of contaminated sites at random intervals. The samples are
then
is processed off line through wet-chemistry methods, often several days or
weeks after the
sample was gathered. The most significant impact of this methodology is that
notification of events affecting the change in water quality parameters do not
occur until
after the change has caused some form of catastrophic event, such as illness
or death in
humans or an entire stretch of river dying due to total consumption of
dissolved oxygen.
2o Additionally, discrete random sampling also causes uncertainty; with no
temporal
correlation of the data, it is often difficult to determine what was a cause
and what was an
effect.
Sensor technology for measuring contaminants or their effects on the ecosystem
continues to improve. Optical-based sensors are especially promising due to
their
25 inherent advantages with respect to sensitivity, large dynamic range,
immunity to
electromagnetic interference, and lightweight profiles. For example, optical
techniques
demonstrating heavy metals detection and classification have been published as
have
2
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
techniques for detecting biological agents, HZS, and the aforementioned water
quality
parameters NNN, CO2, DO, and pH.
Unfortunately, sensor technology for detection is not the total solution. Real-
world problems such as biofouling, environmental extremes, and issues
involving data,
such as transport mechanisms, storage, and analysis, need to be addressed in
parallel with
improvements in sensor technology to affect significant advances in monitoring
the
world's natural resources.
As with the field of environmental monitoring discussed above, monitoring
technologies in the field of electrical power generation, distribution, and
transmission
1o have also been subjected to technical limitations and inefficiencies.
Having timely
knowledge of past and present static and dynamic states in power generation
facilities
and distribution and transmission grids is critical in decision making, power
scheduling,
billing, model studies, planning protection, and maintenance. To date, the
task of
collecting data on a distributed power system has been relegated to a
collection of
disassociated electronic subsystems scattered throughout the grid. All are
ordinarily
standalone designs, most having no high-throughput networking provisions and,
at best,
only the most recent designs employ any digital capability (mass storage, rule-
based
triggering, adaptive process tailoring, etc.). Most previously installed
measurement
systems were designed specifically for a particular task and the concept of
integrating all
2o measurement components into a single body was not possible for a host of
varied
reasons. It is not uncommon to find decision-makers located in the control
room at a
major utility with three or more computer terminals on their desks with
virtually no way
to pass information between them.
Within the last few years, the most important pressure upon electric-power
utilities has been the result of deregulation and the subsequent economic
competition that
it has promoted. In order to remain competitive and profitable, providers of
electric
power have been forced to review all aspects of their operations and seek
methods that
improve efficiency. Of the numerous areas identified where cost savings could
be
3
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
implemented, improving power transfer efficiency, real-time control of power
networks,
and detection and prevention of potential line fault conditions through online
monitoring
all rank in the top target areas for focus and development.
A major impediment to improved power transfer efficiency is existing
transducer
technology. Virtually unchanged over the last several decades, conventional
current/potential transformers are characterized by their bulkiness, expense,
geometry,
large volumes of electrical insulation required when used on high-voltage
lines, and
potential for catastrophic failure. With respect to real-time control of power
networks
and the detectionlprevention of line fault conditions, most types of
conventional
1o transformers exhibit significant bandwidth limitations, restricting their
usefulness in the
monitoring of harmonics and subsequent determination of power quality or the
exact
timing of line fault events.
A 1995 article by the Electrical Power Research Institute (EPRI) indicates
that a
1% increase in efficiency due to improved sensors and instrumentation in coal-
fired
generator plants translates to a savings of over $300 million per year.
Moreover, a 1%
increase in capacity utilization throughout the utilities due to advanced
instrumentation
would result in over $3 billion in saving per year for the industry.
On July 2, 1996, a short-circuit on a 345-kV line in Wyoming started a chain
of
events leading to the breakup and complete islanding of the western North
American
power system. Loads were very high due to local demand in southern Idaho and
Utah
because of temperatures around 100°F. Simultaneously, power exports
from this region
to California were high, causing many of the distribution lines to operate
near capacity.
A flashover to a tree at 2:24 p.m. initiated a chain of events, and when
coupled with the
failure of equipment and harmonic instability within the power distribution
network,
numerous protective devices kicked in to isolate a 5-state area. The impact
was a total
loss of power for over 15 million commercial and residential customers and a
total
estimated revenue loss approaching $2,000,000,000. Furthermore, post analysis
of the
4
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
data that does exist from this outage has indicated that if a real-time, bi-
directional
communications system had been in place, operators or computers would have had
approximately 110 seconds to prevent collapse of the entire grid system,
potentially
saving the utilities and their customers hundreds of millions of dollars.
OBJECTS AND SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide an improved system and
method for remote monitoring.
It is a further object of the invention to provide a remote monitoring system
and
method which provides the capability of delivering sensor data to monitoring
facilities in
1o a timely manner, whereby catastrophic environmental or power delivery
events can be
forseen and averted or minimized.
It is a further object of the invention to provide a remote monitoring system
and
method which can be practiced in a less costly and less labor-intensive manner
than those
of the prior art.
In a preferred embodiment, the invention provides a system for gathering,
transmitting, and storing data captured from remote monitoring sites
positioned in the
field, with specific applicability to distributed chemical sensing and
reporting, as well as
distributed power monitoring and reporting. Transducers monitoring water
quality
parameters or electrical power parameters have their data transmitted to the
Internet or
2o Intranet via a communications link. From here, the data is relayed to
secure servers
where it is formatted, analyzed, and stored for later retrieval by a customer.
If alarm
conditions exist that require immediate customer notification, notifications
are sent via
one or more telecommunications means, including pager, cellular telephone, or
email.
With respect to the distributed chemical sensing embodiments, the invention
preferably
utilizes fiber optic chemical sensors that addresses the problem of
biofouling. Using anti-
5
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
fouling measures, the invention can provide continuous, long-term waterway
monitoring.
With respect to distributed power monitoring and reporting, the invention
preferably
utilizes a fiber optic optical current transducer system for the measurement
of magnetic
fields in electric power and power electronic applications. The transducer is
based upon
rare-earth iron garnet (REIG) crystals that exhibit the Faraday effect when
placed in a
magnetic field. This transducer is extremely lightweight, making retrofitting
of existing
distributed power monitoring grids extremely cost effective. In both cases,
the respective
sensor technologies are coupled with wireless telecommunications and network
infrastructures to provide businesses with the ability to shift from a
reactive to a proactive
mode of operation, enabling them to become more efficient in their business
operations.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other objects, features, and advantages of the invention
will be
apparent from the following more particular description of preferred
embodiments as
illustrated in the accompanying drawings, in which reference characters refer
to the same
parts throughout the various views. The drawings are not necessarily to scale,
emphasis
instead being placed upon illustrating principles of the invention.
FIG. 1 is a block diagram illustrating the overall operation of the hardware
and
software of the system of the invention in accordance with a preferred
embodiment.
2o FIG. 2 is a block diagram illustrating the basic fimctions of the remote
field unit
of the invention.
FIG. 3 is a fimctional block diagram illustrating the solar array power
subsystem
of the invention.
FIG. 4 is a state diagram illustrating the modes of operation for the RFU of
the
invention.
6
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
DETAILED DESCRIPTION
FIG. 1 is a block diagram illustrating overall hardware and software system
operation of the present invention in accordance with a preferred embodiment.
Transducers that monitor water quality parameters or electrical power
parameters have
their data transmitted to the Internet or Intranet via a communications link.
From here,
the data is relayed to secure servers, where it is formatted, analyzed, and
stored for later
retrieval by a customer. If alarm conditions exist that require immediate
customer
notification, such notifications are sent to a customer via one or more
telecommunications means, including pager, cellular telephone, or email. Other
known
l0 means for providing such notification over a telecommunications network are
possible
without departing from the spirit and scope of the invention.
The following sections further describe detail and options surrounding the
preferred system implementation.
FIELD IMPLEMENTATION - HARDWARE CONFIGURATION
A preferred remote field unit (RFU) is considered a ground-based satellite
and, as such, is
completely autonomous. An RFLT can contain units performing various functions,
including:
~ A sensor function,
~ A signal processing function,
~ A control function, -
~ A power function,
~ A tamper function,
~ A global positioning system (GPS) function, and
~ A two-way telemetry function.
7
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
FIG. 2 shows the relationship of the above functions; an overview of their
operation follows.
Sensor Function
The sensor function is a physical interface between a quantity being measured
and
an RFU. Possible sensor inputs are listed in the lower left corner of FIG. 1.
This list is
not considered exhaustive; other possible sensor input will be apparent to
those skilled in
the art. Multiple sensors can form the sensor function.
Signal Processing Function
A signal processing function preferably contains three inputs or input sets:
(1) a
i0 set of inputs from a sensor function, (2) a set of inputs from a control
function, and (3) a
set of inputs from a power function. Additionally, a signal processing block
can contain
a set of outputs to a control function. The primary task of a signal
processing block is to
convert physical signals) from a sensor function to numerical representations
of a
measured signal. The signal processing function is under program control from
the
control function, from where it derives all algorithmic manipulations of the
sensor
signal(s), timing information, and self diagnostic instructions. The signal
processing
function derives its power from the power function.
The output of this block consists of formatted sensor data as well as control,
indicator, and diagnostic information.
Contained within this function are all electronics and optics necessary to
convert
the signals from the sensor function to their representative values.
Addirionally, inputs
from third-party devices are included in this function.
8
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
Control Function
The control function preferably operates under program control and is a state
machine. A preferred control block embodiment can receive five inputs: (1) a
set of
inputs comprised of formatted sensor data as well as control, indicator, and
diagnostic
information from the signal processing function, (2) a set of inputs comprised
of indicator
information from tamper alarms, (3) a set of inputs comprised of control data
as well as
control, indicator, and diagnostic information from the telemetry function,
(4) a set of
inputs from the global positioning system, and (5) a set of inputs from the
power
function.
1o A preferred control block embodiment can also receive two inputs: (1) a set
of
outputs to the signal processing function and (2) a set of outputs to the
telemetry function.
The set of outputs to the signal processing function are used to acknowledge
data sent
from the signal processing function as well as to control the mode of
operation of the
signal processing function. The set of outputs to the telemetry function is
used to transfer
sensor data to the telemetry function as well as control information.
The control function is the "heart" of the RFIJ. Depending upon the mode of
operation, the control function will orchestrate all inter-processor
communications,
diagnostic functions, as well as data formatting, storage, and relaying.
Additionally, the
control function will perform periodic "state-of health" diagnostics of all
system
2o parameters to ensure proper operation. Finally, the control function
formats system data
into a desired data comrriunications protocol or protocols, and translates
incoming
formats into system command sequences.
Telemetry Function
The telemetry function serves the purpose of transmitting data from the RFU as
well as receiving data intended for the RFU. Telemetry can be implemented
through a
variety of hardware implementations, depending upon the physical RFU
geographic
9
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
location or anticipated RFU functionality. Such hardware implementations can
include,
but are not limited to:
(1) Wireline interface,
(2) Wireless point-to-point radio-frequency (PPRF) interface,
(3) Wireless cellular interface, and
(4) Wireless RF satellite interface.
Wireline interfaces are preferably implemented whenever there is a direct
connection available to plain old telephone service, known in the telecom
industry as
POTS. This would allow the RFU to directly dial into the Internet/Intranet via
a local
service provider (ISP), and as of this writing, is the most cost-effective
data transfer
methodology.
Wireless PPRF interfaces are preferably implemented whenever POTS is not
available. This configuration increases overall initial system costs due to
the need for
multiple transceivers, but over time becomes the next cost-effective data
transfer
methodology. An RFU would connect via direct radio link to a corresponding
base unit,
the latter directly connected to POTS.
An alternative PPRF implementation can allow an RFLJ to transmit data from
other RFUs. In this embodiment, an RFU which is incapable of directly
transmitting data
to a base unit can transmit data to another RFU, which can in turn transmit
received data,
as well as data collected at the RFU, to another RFU or directly to a base
unit, if such a
base unit is available. An FtFLJ receiving data from another RFU may store
received
data, or may open communications with another RFU or base station and
retransmit such
data as it is received.
Wireless cellular interfaces are preferably implemented when POTS is not
available, PPRF is not desired or practical, and cellular coverage is assured.
As with a
to
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
POTS implementation, an RFU can directly dial into the Internetllntranet via
an ISP.
This is the next mostly costly alternative due to the monthly charges of
cellular airtime.
Finally, wireless RF satellite interfaces can be used any time the previous
telemetry options are not available. This option represents the greatest cost
to the
customer due to the costs of satellite bandwidth usage.
Tamper Function
The tamper function is incorporated into the RFU and provides alarm
notification
that the system is being tampered with or that diagnostics have failed. This
is an output-
only function that provides its status word to the control function.
l0 GPS Function
The GPS function serves two purposes: (1) provide a very precise (< 10e-5
second resolution) time stamp to the data, and (2), if the RFU is installed on
a mobile
platform, provide extremely accurate global positioning information for
incorporation
into the status word. The former is used to specifically time-correlate
multiple RFU data
sets at the network operations center, with the latter can be used by RFUs
that are mobile
in design (such as autonomous underwater vehicles).
Power Function
The power system can be driven from standard electrical or battery power where
delivery and maintenance of such power is economically feasible.
Alternatively, power
2o can be generated at or near an RFLJ through a variety of alternative energy
means,
including, but not limited to, solar power, hydrodynamic power, or windmills.
The latter
represents the most probable solution for the majority of the RFUs.
FIG. 3 illustrates a preferred power system embodiment which utilizes solar
power. Such a power system can consist of a solar array panel, a power system
regulator,
11
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
and a battery. The function of each of the blocks is straightforward and is
explained
below.
Solar Array. The solar array function converts light from the sun into useable
energy.
Array output can typically fluctuate from 0 (darkness) to nearly 22 vdc in
direct sunlight,
no load.
Power System Regulator (PSR). The PSR's primary goal is to ensure that the
load bus
remains at constant voltage, independent of the input from the solar array or
battery. To
accomplish this, the PSR is comprised of both a buck and boost regulator.
The boost regulator is activated any time the battery voltage drops below the
bus
to regulation voltage, typically 12 vdc. At the expense of a greater drain in
power on the
battery, a load bus can be maintained at or near bus regulation voltage.
The buck regulator performs the opposite function - any time the bus voltage
exceeds the normal setpoint value the buck regulator will reduce the amount of
voltage
on the bus by either 1) shunting energy through large MOSFETs connected to a
heatsink,
or 2) delivering the excess energy to the battery charger circuit so that the
battery
reserves are maintained.
Battery. This is typically a gelled electrolyte battery that has the advantage
of not
stratifying like conventional lead-acid types. The use of "environmentally
friendly"
batteries that are non-spillable and sealed are preferably used so that
transport to the
2o installation site will require no additional safety precautions.
A PSR monitoring function can provide digital and analog outputs to indicate
PSR status. Typically, most PSRs use binary bits to indicate current
operational mode
(boost, charging, floating, and the like) and any abnormal conditions. Analog
outputs are
scaled voltages of the amount of voltage being produced by the array, the load
on the
12
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
battery (from the load bus), and the charging current to the battery. This
information may
be integrated into the status word reported from the remote site.
FIELD IMPLEMENTATION - MODES OF OPERATION
The RFU is preferably a state machine operating under program control. Three
principle modes of operation are preferably provided: standby (STBY), runtime
(RUIN,
and transmission/reception (RF). FIG. 4 is a state diagram illustrating
preferred RFLJ
operation modes and their interoperation. Each mode is described below.
STBY State
The duty cycle of data collection can span from as little as one sample per
day to
1o nearly continuous sampling. For those situations or appncanons wnere
conmu~u~
sampling is not required or when RFU communication is not necessary, power-
consuming devices such as sensors, a controller, and a transceiver, can be
taken offline to
minimize power system battery drain, thereby extending battery lifetime.
Processor functions are under program control. Timing is provided by an
onboard
watchdog timer that also provides a master timestamp for all data gathered.
While in
standby mode, a processor can run "scrub" operations, including diagnostics
and
peripheral scans of the tamper switches.
In the event diagnostic or tamper switches indicate an abnormality, the
processor
will power the system and attempt to immediately transmit an alarm
notification. After
2o alarm transmission and acknowledgement reception, the system will return to
STBY
mode.
RIJN State
The RIJN state is the data collection mode, and can be attained from the RLTN
state, RF state or the STBY state. At predetermined times under program
control, the
13
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
system can initiate an environmental data sampling cycle. If in the STBY
state, power
will be applied to the data collection circuitry. After a warm-up requirement
has been
met data will be gathered from the system. After processing, the data will be
stored
onboard in memory until emptied by a transition from the RUN to RF states. If
the
program indicates a return to the STBY state the power to the data collection
circuitry
will be removed until the next acquisition period.
The RUN state can also be entered from the RF state. After data transfer, if
the
program indicates that continuous monitoring is required, the system will
return to data
collection mode and will log data as previously described.
to Finally, RUN state is reentrant. If the program determines that continuous
data
collection is required, but it is not time to transmit, then the sequence will
loop until a
transition to the RF state occurs.
RF State
RF state can be entered from either the STBY state or from the RUN state, as
in the case
where data must be offloaded. There are two conditions that may cause the RF
state to be
entered from STBY state: alarm and receive. If an alarm is generated, power
will be
applied to the transceiver and data will be formatted and sent to the
transceiver. After
reception of the acknowledgement, the system will transition back to the STBY
state,
deenergizing the transceiver.
The remote system may also be configured to receive commands while still
conserving battery life. This is accomplished by the setting processor's
watchdog timer
to an appropriate interval. Each time the watchdog timer "wakes up" the
processor, it
turns on the receiver and listens for a predetermined length of time. If there
is no
information "on the air", the receiver is turned off and the processor returns
to the low
power STBY state. If there is information, the information is received, passed
to the
processor, and the appropriate action taken. System designers can extend the
life of the
14
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
battery by increasing the time between receive intervals at the expense of
control delay.
The interval itself may be modified. This will allow the system to be more
interactive
when necessary.
If entry to the RF state occurred from the RUN state, the system will transmit
the
data stream and upon receipt of the acknowledgement, will return to the RUN
state to
collect data.
In an alternative embodiment, an RFU can alternate between RUN and STBY
states independent of data transmission needs. Data collected by an RFU can be
stored in
a first in, first out (FIFO) queue; database; or other data storage system.
Such data can
l0 then be read as necessary by a data transmission system. Data transmission
can begin at
the occurrence of one or more events, such as elapsing of a specific time
interval or
collection of a requisite number of data samples. Transmitted data may be
removed from
a data storage system, thereby reducing RFU data storage requirements. As with
the
previously described embodiment, a watchdog timer or other device can trigger
periodic
monitoring for inbound data.
FIELD IMPLEMENTATION - DEPLOYMENT
The RFU can be fixed or mobile in configuration. Examples of fixed unit
locations for water quality monitoring are effluent monitoring points, lakes,
streams,
rivers, aquifers, etc. Examples of fixed unit locations for the power
monitoring industry
are at tie points between generation and transmission subsystems, as well as
between
transmission and distribution subsystems.
Mobile applications for RFUs are envisioned using remote, autonomous
underwater vehicles to sample the water column. This system could be the basis
of a
world-wide ocean or river observing system and would provide tremendous
information
concerning the changing ecosystems surrounding our waterways.
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
TELECOMMUNICATIONS CONSIDERATIONS
Locations for monitoring sites will vary widely. For this reason, there is no
single
solution that is appropriate for all locations. Two factors must be considered
with
designing the communication link between the remote system and the host: Total
Life
Cycle Cost and availability. To achieve an optimum communication link, the
link that
meets the availability criteria at the lowest Total Life Cycle cost will be
selected.
Communications link options will include, but are not limited to: land
telephone
lines (POTS), wireless land mobile, unlicensed Part 15 systems, AMPS Cellular
(including CDPD and Cellemetry), RAM Mobile Data, ARDIS, and satellite systems
(PanAm, Teleos, Orbcomm, Inmarsat-C, Argos, Qualcomm, Hughes, others) as
available.
The selection procedure should take into consideration the location of the
remote site
(terrain and coverage from communications providers) as well as the Total Life
Cycle
Cost of the system. Mixed systems may also be provided. These may use a
combination
of different communications systems to make a single link. For example, an
inexpensive
Part 1 S device to transmit from a location with no phone line to a location
with phone
service (potentially saving thousands of dollars in special charges to run the
phone line to
the remote site).
HOST IMPLEMENTATION
2o A single T1 or other high speed data communications line may provide
bandwidth
for a plurality of remote units. The exact number of such remote units
supported by such
a data communications line will depend on RFU sampling frequency and data
size, but it
is anticipated that a Tl line will easily support as many as 100 remote units.
Data received through such a data communications line may pass through a
firewall computer to dedicated servers. Such servers can be built upon a SCSI
backbone
with R.A>D redundancy, and can both store incoming data and service user
requests. To
16
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
ensure maximum reliability and minimum download time for customers, multiple
"redundant" connections to high-speed data networks may also be maintained.
Further
reliability can be achieved by utilizing a router and/or switch solution that
incorporates
advanced BGP4 routing technology or other similar technologies. Such a router
configuration can allow a system operator to load balance bandwidth through
multiple
circuits. Such load balancing allows the routers to automatically compensate
for any
outages by using alternate circuits. The architecture outlined above provides
a high
availability, scalable data storage, analysis, and presentation platform
capable of storing
data from a large number of RFU's, storing such data for an indefinite period
of time, and
to providing users with readily accessible data analysis and data presentation
capabilities.
CUSTOMER INTERACTION
The customer is preferably provided with all RFU data through a standard
Internet
or Intranet interface, such as, Microsoft's Internet Explorer or Netscape's
Communicator
browsers running on personal computers. Other forms of visual access may be
provided
via web-enabled telephones, personal data organizers and assistants, netbooks,
and the
like. Voice-access may be provided through standard telephones, cellular
telephones, and
third-part service agencies.
Software
2o The software preferably resides on the host, and may be written in the Java
and
XML programming languages. This removes most compatibility issues with
individual
personal computer or other web-enabled platforms, and allows the system to be
used by
the largest base of customers and interface platforms. Content may be "pushed"
from the
host to the customer's browser on an as-required basis.
17
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
Data Analysis
The form of data analysis will be determined by the customer using vanous
methods of selection, including pull-down menus, pre-loaded scripts, etc. The
user
preferably has the option to load specific algorithm packages onto their local
machine or
use the host server to perform all analysis. Furthermore, time histories,
geographical
mapping, and trend analysis are some of the many options available to the
customer.
Database Generation
RFU data can be time stamped as well as positional stamped (mobile RFUs only).
to This enables the development of tremendous data sets on the performance of
networks in
a manner that has never been attempted. In the case of environmental data,
these data
sets can be correlated with space-based imagery to provide a better picture of
developments on the globe. In the case of power system monitoring, disturbance
propagation can be tracked and analyzed in a fashion that, before
implementation of the
present invention, has never been possible.
RFU/Customer Data Exchange
Two forms of data exchange are processed by the system: (1) data that is
initiated
from the customer, such as alarm setpoints, request for diagnostics, current
position, and
request for immediate sample, and (2) standard reporting data from the RPU.
The
2o customer has the ability to set alarm setpoints and notification strategies
(pager,
telephone, email, etc.) iri theta vent that the RFLJ data falls outside
acceptable limits.
DISTRIBUTED CHEMICAL SENSING
A distributed chemical sensing embodiment of the present invention preferably
utilizes a non-mechanical, non-toxic (i.e. non-metal oxide) methodology for
protecting
optical based sensors from biofouling in many environments, including
freshwater,
saltwater, wastewater, etc. The anti-biofouling methods of the invention
provide remote
18
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
sensors with the cabability of long-term deployment in aquatic environments
without user
intervention or mechanical action.
The preferred anit-fouling means comprises an anti-fouling coating on the
optical
sensor element. Requiring significantly less maintenance than conventional
technologies,
these coatings enable the sensors to remain in the field for extended periods
of time. This
in turn substantially reduces the high maintenance requirements associated
with
conventional sensor technologies, thus enabling distributed sensing
infrastructure
development and deployment. Such coatings are taught in more detail in the
U.S.
Provisional Patent Application entitled "Anti-biofouling Method and Apparatus
for
Optical Sensors," filed April 24, 2000, by inventors Paul G. Duncan et. al,
the entire
disclosure of which is incorporated herein by reference.
DISTRIBUTED POWER MONITORING AND REPORTING
Embodiments of the invention which are designed for distributed monitoring of
electrical power generation and transmission preferably use an optical
magnetic field
sensor element such as that disclosed in co-pending U.S. Patent Application
Serial No.
09/421,399 entitled "Methods and Apparatus for Optically Measuring
Polarization
Rotation of Optical Wavefronts Using Rare Earth Iron Garnets," filed October
21, 1999,
the entire disclosure of which is incorporated herein by reference. The
extremely high
bandwidth (>700 MHz) of such sensor elements is only limited by the speed of
the signal
2o processing electronics to convert the optical signal to a control or
indicator value. One
estimate of the bandwidth heeds of the power industry per sensor element is
five times
the S 1 S' harmonic of the line frequency, which is approximately 15 kHz, or
45 times
lower than the demonstrated 700 MHz limit. For disturbance monitoring, where
events
occur in microsecond periods, the above-described optical sensors will have no
trouble
seeing the fault.
19
CA 02407512 2002-10-25
WO 01/82028 PCT/USO1/13213
The following are other features of such sensors which are not available with
conventional current transducers, and which provide significant advantages in
the present
application with respect to deployment and use of large numbers of wide-area
sensors
and their support systems:
I E; R ~ t ~~ i ~ t . .T11
4 ~~o ~t~ I ~~ i'I ~I~ ~ j~l I4
~~~~
~~ I
, Immediate savings in investment of
Low cost sensor transducer
technology, allowing greater numbers
to be deployed.
I Sensor and interconnect~ Immune to electro-magnetic interference
is
I
fiber-optic based ~ Intrinsically safe and isolated
from high
voltages, hence do not contain explosive
insulating oils
Lightweight
Support equipment can be positioned
great
distances from the sensing location
Sensor can measure ~ Enables waveform analysis to improve
high
frequency waveforms efficiency and reduce delivery costs
Allows utilities to address power
quality issues
that saves them and their customers
money
Sensor does not saturate~ Removes potential for catastrophic
explosions
Provides continuous data independent
of load
conditions
While the invention has been particularly shown and described with reference
to a
preferred embodiment thereof, it will be understood by those skilled in the
art that
various changes in form and details may be made therein without departing from
the
spirit and scope of the invention.
