CLAIMS:
1. A sensing platform for monitoring a transmission system, comprising:
a sensor, said sensor sensing one or more conditions selected from the group
consisting essentially of:
a condition of the transmission system; and
a condition of an environment around the transmission system,
said sensor producing an output signal related to the sensed condition;
a control system operatively associated with said sensor and responsive to the
output signal produced by said sensor, said control system producing output data
based on the output signal produced by said sensor; and
a transmitter operatively associated with said control system, said transmitter
transmitting the output data from said control system.
2. The sensing platform of claim 1, wherein said sensor comprises one or more
selected from the group consisting essentially of an accelerometer, an acoustic sensor, an
optical sensor, and a temperature sensor.
3. The sensing platform of claim 2, wherein said accelerometer comprises a two-
axis accelerometer.
4. The sensing platform of claim 2, wherein said optical sensor comprises an
infra-red detector.
5. The sensing platform of claim 1, wherein said transmitter comprises a radio-
frequency transmitter.
6. The sensing platform of claim 1, further comprising a power converter
operatively associated with the transmission system, said power converter extracting energy
from the transmission system and converting the extracted energy into a form useable by said
sensing platform.
7. The sensing platform of claim 6, wherein the transmission system comprises
an electrical power transmission system and wherein said power converter comprises an
inductive converter.
8. The sensing platform of claim 1, further comprising a receiver, said receiver
receiving transmitted signals from another sensing platform.
9. The sensing platform of claim 8, wherein said receiver and said transmitter
comprise a transceiver.
10. A system for monitoring a transmission system, comprising:
a plurality of sensing platforms operatively associated with the transmission
system at a corresponding plurality of locations along the transmission system, each of
said plurality of sensing platforms comprising: a sensor, said sensor sensing one or more conditions selected from the
group consisting essentially of:
a condition of the transmission system; and
a condition of an environment around the transmission system,
said sensor producing an output signal related to the at least one condition
sensed;
a control system operatively associated with said sensor and responsive
to the output signal produced by said sensor, said control system producing
output data based on the output signal produced by said sensor; and
a transceiver operatively associated with said control system, said
transceiver transmitting the output data from said control system; and
at least one endpoint receiver, said at least one endpoint receiver receiving
output data transmitted by said at least one of said plurality of sensing platforms.
11. The system of claim 10, further comprising a user-interface system operatively
associated with said at least one endpoint receiver.
12. A method for monitoring a transmission system, comprising:
sensing one or more conditions selected from the group consisting essentially
of:
a condition of the transmission system; and
a condition of an environment around the transmission system; and
transmitting data related to the sensed condition.
13. The method of claim 12, further comprising:
determining whether said sensed condition is a normal condition or an
anomalous condition; and
transmitting information about the anomalous condition when the anomalous
condition is determined.
14. The method of claim 12, further comprising:
receiving the transmitted data related to the sensed condition at an
intermediate transceiver;
re-transmitting data related to the sensed condition; and
receiving the re-transmitted data at an endpoint receiver.
15. The method of claim 12, wherein transmitting data related to the sensed
condition comprises transmitting radio frequency signals.
16. The method of claim 12, wherein the transmission system comprises a power
transmission system having power lines and wherein transmitting comprises transmitting via
the power lines.
17. A sensing platform, comprising:
sensor means for sensing one or more conditions selected from the group
consisting essentially of:
a condition of a transmission system; and a condition of an environment around the transmission system,
and for producing an output signal related to the sensed condition;
means, operatively associated with said sensor means, for operating said
sensor means and for processing the output signal from said sensor means to produce
output data; and
means for transmitting the output data. |
METHODS, APPARATUS, AND METHODS FOR MONITORING TRANSMISSION SYSTEMS
Related Applications
This application claims benefit of U.S. Non-provisional application No. 11/425,287,
filed June 20, 2006, entitled METHODS, APPARATUS, AND METHODS FOR MONITORING TRANSMISSION SYSTEMS, which is incorporated herein by reference in
its entirety.
Contractual Origin of the Invention
This invention was made with United States Government support under Contract No.
DE-AC07-05ID14517 awarded by the United States Department of Energy. The United
States Government has certain rights in the invention.
Technical Field
This invention relates to sensing systems in general and more specifically to methods,
apparatus, and systems for monitoring transmission systems.
Background
Transmission systems, such as pipelines, cell towers and electrical power transmission
systems, can be damaged in a variety of ways, including damage by weather, by accidents,
and by intentional sabotage, just to name a few. Of course, many elements of such
transmission systems are often located in remote areas where monitoring of the systems may
be quite difficult, dangerous, and expensive. However, damage to these transmission systems
can result in even more costly and extensive repairs. For example, damage to multiple towers
of an electrical power transmission system could cause cascading or 'rolling' blackouts.
Early notification of damage to a transmission system can provide several benefits. If
a transmission system operator is informed that an event is forthcoming then the operator can
follow a procedure for mitigating the consequences of that event. For electrical power
transmission systems, for example, an operator could take steps to localize the problem, thus
minimizing or preventing the occurrence of cascading blackouts. Additionally, if an operator
is informed that an event, such as intentional sabotage, is happening at a given location, the
operator can alert local law enforcement authorities so that the intruder may be captured.
Monitoring of transmission systems may also provide an opportunity for enhancing security
or monitoring of remote locations, such as border areas.
Summary of the Invention
One embodiment of a sensing platform for monitoring a transmission system may
comprise a sensor that senses one or more conditions relating to a condition of the
transmission system or and/or the condition of an environment around the transmission
system. A control system operatively associated with the sensor produces output data based
on an output signal produced by the sensor. A transmitter operatively associated with the
control system transmits the output data from the control system.
A system for monitoring a transmission system may comprise a plurality of sensing
platforms operatively associated with the transmission system at a corresponding plurality of
locations along the transmission system. Each sensing platform may include a sensor that
senses one or more conditions of the transmission system, a control system that produces
output data based on output signals from the sensor, and a transceiver that transmits the
output data from the control system. At least one endpoint receiver receives the output data
transmitted by a sensing platform.
A method for monitoring a transmission system may involve the steps of: Sensing
one or more conditions of the transmission system and/or an environment around the
transmission system, and transmitting data related to the sensed condition.
Brief Description of the Drawing
Illustrative and presently preferred embodiment of the invention are shown in the
accompanying drawing in which:
Figure 1 is a pictorial representation of a system for monitoring a transmission system
according to one embodiment of the invention;
Figure 2 is a side view in elevation of one embodiment of a sensing platform with a
portion of the housing broken-away to reveal the internal subsystems and components;
Figure 3 is an exploded perspective view of the sensing platform illustrated in Figure
2;
Figure 4 is a schematic block diagram of the sensing platform illustrated in Figures 2
and 3;
Figure 5 is a schematic block diagram of a data processing routine utilized by the
control system; and
Figure 6 is a schematic block diagram of an analysis routine.
Detailed Description of the Preferred Embodiments
One embodiment of a monitoring system 10 is shown in Figure 1 as it may be used to
monitor a portion, or even substantially the entirety, of a transmission system 12. By way of
example, in one embodiment, the transmission system 12 may comprise an electrical power
transmission system 38, although the invention may be used with other types of transmission
systems as well. Briefly, the monitoring system 10 may comprise a plurality of individual
sensing platforms 14 provided at various locations 16 along the transmission system 12.
Monitoring system 10 may also comprise at least one endpoint receiver 18. Endpoint receiver
18 may be positioned so that it receives information 20 transmitted by at least one of the
plurality of sensing platforms 14. In the embodiment shown and described herein, endpoint
receiver 18 may be operatively associated with a user interface system 22, such as, for
example, a personal computer, to allow a user (not shown) to interpret and/or act on the
information 20 received by endpoint receiver 18. In addition, and as will be described in
greater detail below, user interface system 22 may also allow the user to transmit information
or programming instructions to the various sensing platforms 14.
Referring now primarily to Figures 2-4, each sensing platform 14 may be identical to
the others (although this need not be the case), and may comprise a chassis or housing 24
sized to receive the various components and subsystems comprising the individual sensing
platform 14. For example, in one embodiment, the sensing platform 14 may comprise at least
one sensor 26, a control system or processor 28, and a transmitter 30. The sensing platform
14 also may be provided with a receiver 32, in which case the combination of the transmitter
30 and receiver 32 may be referred to herein in the alternative as a transceiver 34.
The one or more sensors 26 comprising the sensing platform 14 may be used to sense
one or more conditions of the transmission system 12 and/or one or more conditions of an
environment around the transmission system 12. In one embodiment, the control system or
processor 28 is operatively associated with the sensor(s) 26 and is also responsive to an
output signal(s) 36 produced by the sensor(s) 26 that relates to the sensed condition(s). The
control system 28 produces information 20 that relates to or is derived from the sensed
condition. The transmitter 30 is then used to transmit the information 20 produced by the
control system 28.
The sensing platform 14 may also be provided with a power conversion system 72.
Power conversion system 72 extracts energy from the transmission system 12 and converts it
into a form useable by the sensing platform 14. For example, in an embodiment wherein the
transmission system 12 comprises an electrical power transmission system 38, the power
conversion system 72 may comprise an inductive power converter 74. Briefly, inductive
power converter 74 may comprise a wire coil 76 positioned so that it is within an alternating
magnetic field (shown schematically at "B" in Figure 4) surrounding an electrical conductor
40 of the electrical power transmission system 38. The alternating magnetic field B induces
an alternating electric current in wire coil 76 which may then be rectified and/or regulated by
the inductive power converter 74 so that it is useable by the sensing platform 14.
In a typical operational example, each sensing platform 14 monitors at least one
condition of the transmission system 12, such as, for example, vibrations detected in the
transmission system 12 due to an event 55 occurring on or nearby tower 42. See Figure 1.
Alternatively, each sensing platform 14 may monitor at least one condition of an environment
around the transmission system 12, such as, for example, an ambient temperature or light in
the infra-red wavelength range that may be emitted by various objects or persons in the
environment around the transmission system 12. The control system 28 of each sensing
platform 14 may be configured to evaluate or analyze the output signals 36 produced by the
sensor or sensors 26 to produce information 20. For example, in one embodiment, the control
system 28 analyzes the output signal(s) 36 from the sensor(s) 26 to determine whether the
sensed condition is a normal condition or an anomalous condition. If the sensed condition is
determined to be an anomalous condition, the control system 28 may operate the transmitter
30 of the sensing platform 14 to transmit information 20. The transmitted information 20 is
ultimately received by the endpoint receiver 18. If the sensed condition is determined to be a
normal condition, then no information need be sent, although it could be.
In this regard it should be noted that, in a typical embodiment, the endpoint receiver
18 will be located at a position beyond the transmitting range of most of the individual
sensing platforms 14. Therefore, in order to ensure that the transmitted signal from any one
of the individual sensing platforms 14 will be received by the endpoint receiver 18, each
sensing platform 14 may be provided with a transceiver 34 (i.e., a transmitter 30 and a
receiver 32). Consequently, in an embodiment wherein the monitoring system 10 comprises a
plurality of sensing platforms 14 having such transceivers 34, signals transmitted by one
sensing platform 14 may be received by one or more nearby sensing platforms 14. The
nearby sensing platform(s) 14 may then re-transmit the signal. See Figure 1. In this manner,
the transmitted signal may be relayed by various ones of the sensing platforms 14 comprising
the monitoring system 10 until the signal is ultimately received by the endpoint receiver 18.
Additional redundancy may be realized by providing the system 10 with two or more
endpoint receivers 18 located at different positions along the transmission system 12. If, for
some reason, the signal from a sensing platform 14 fails to be relayed by nearby sensing
platforms 14 along one direction, (thus fails to reach a first endpoint receiver 18), the signal
from sensing platform 14 relayed by nearby sensing platforms in the other direction may be
received by a second endpoint receiver 18 located at the different position. Of course, the
provision of additional endpoint receivers 18 at various points along the transmission system
12 may provide additional measures of redundancy.
Once the information 20 is received by the endpoint receiver 18 it may be presented in
human-readable form, thereby allowing a user or system operator to interpret and/or act upon
the information 20, as the case may be. In the embodiment shown and described herein, the
endpoint receiver 18 is operatively associated with a user interface system 22 for this purpose.
The user interface system 22 may present the received information 20 on a display system 78.
For example, if the information 20 relates to an anomalous condition (e.g., event 55, Figure 1)
detected by one or more of the sensing platforms 14, the user interface system 22 may provide
an indication about the anomalous condition, what it may relate to (e.g., vibrations,
temperature, or infra-red signature), as well as the particular sensing platform or platforms 14
that detected the anomalous condition. Additional information, data, and options may also be
provided by user interface system 22, as will be described in further detail herein.
One advantage of the present invention is that it may be used to monitor a
transmission system 12 and to provide to an endpoint receiver 18 information 20 regarding
one or more monitored conditions. In one exemplary embodiment, the information 20
regarding the one or more monitored conditions may be evaluated by a user to make a
determination about whether the integrity of the transmission system 12 is, or may soon be,
compromised. Alternatively, in another exemplary embodiment, a user may utilize the
information 20 about the monitored condition or conditions for purposes other than
evaluating the integrity and security of the transmission system 12. For example, the
information 20 provided by one or more of the sensing platforms 14 may be utilized to derive
information about the passage of persons or vehicles within sensing range of one or more of
the individual sensing platforms 14. Still other purposes and variations are possible, as would
become apparent to persons having ordinary skill in the art after having become familiar with
the teachings provided herein. Consequently, the methods, apparatus, and systems shown and
described herein should not be regarded as limited to any particular purpose.
Still other advantages are associated with the power conversion system 72 which may
be provided in each of the sensing platforms 14. For example, deriving from the transmission
system 12 the energy required to operate the individual sensing platforms 14 dispenses with
the need to provide each individual sensing platform 14 with a separate power supply (e.g., a
storage battery) capable of operating the sensing platform 14. Accordingly, the power
conversion system 72 will allow the individual sensing platforms 14 to be readily located at
even remote areas along the transmission system 12 without concern for providing a separate
power source (e.g., a storage battery) to the sensing platforms 14. Of course, the arrangement
also dispenses with the need to periodically service or replace the storage battery.
Still other advantages are associated with the monitoring system 10. For example,
and as shown and described herein, a plurality of individual sensing platforms 14 may be
mounted at various locations 16 along the transmission system 12, thereby allowing extended
portions, or even substantially the entirety, of the transmission system 12 to be monitored.
Alternatively, only selected portions of the transmission system 12 may be monitored with the
system 10. In addition, the ability of the sensing platforms 14 to relay transmissions from
adjacent sensing platforms 14 allows low-power transmitters (e.g., transceivers) to be
utilized. The signal relaying capability also dispenses with the need to provide more than one
endpoint receiver 18, although multiple endpoint receivers 18 may be provided if so desired.
In addition, the signals transmitted by the individual sensing platforms 14 are typically of
sufficient strength so that they may be received by more than one adjacent sensing platform
14. Consequently, the signal may continue to be relayed even though one of the sensing
platforms 14 receiving the transmitted signal may be unable to re-transmit (e.g., relay) the
signal.
Moreover, it should also be noted that the various individual sensing platforms 14 and
monitoring system 10 are not limited to use with electrical power transmission systems, but
could also be used with other types of transmission systems, such as, for example,
telecommunications (i.e., telephone) systems, oil pipelines, gas pipelines, water pipelines, or
other types of systems for moving or transmitting resources, such as electricity or materials,
from one location to another.
Having briefly described one embodiment of the methods, apparatus, and systems for
monitoring transmission systems, as well as some of their more significant features and
advantages, various exemplary embodiments of the invention will now be described in detail.
Referring back now to Figure 1, an exemplary embodiment of a monitoring system 10
is shown and described herein as it may be used to monitor a transmission system 12. The
transmission system 12 may comprise an electrical power transmission system 38 having a
plurality of electrical conductors 40 supported by a plurality of support towers 42.
Alternatively, the monitoring system 10 may be used with other types of transmission
systems, such as, for example, telecommunications (i.e., telephone) systems, oil pipelines, gas
pipelines, water pipelines, or other types of systems for moving or transmitting resources,
such as electricity or materials, from one location to another. Consequently, the present
invention should not be regarded as limited to use with any particular type of transmission
system 12.
The monitoring system 10 may comprise at least one, and typically a plurality of
sensing platforms 14 provided at various locations 16 along the transmission system 12. For
example, in the embodiment shown and described herein wherein the transmission system 12
comprises an electrical power transmission system 38, the various sensing platforms 14 are
mounted to one of the electrical conductors 40 at locations 16 nearby the support towers 42.
So positioning the various sensing platforms 14 nearby the support towers 42 will allow the
sensing platforms 14 to more easily monitor conditions (e.g., event 55) on and around the
support towers 42. Of course, other positioning arrangements may be utilized depending on
the particular type of transmission system 12 and the conditions to be monitored.
Before proceeding with the description, it should be noted that the various ones of the
sensing platforms 14 comprising the monitoring system 10 may be identical to one another,
although this need not be the case. For example, in an alternative embodiment, various ones
of the sensing platforms 14 comprising the monitoring system 10 may be provided with
different sensing capabilities depending on where they are to be located on the transmission
system 12 and depending on the particular condition(s) that is/are desired to be sensed. In
addition, various ones of the sensing platforms 14 may include or lack certain other
components (e.g., a transmitter 30 or receiver 32), again depending on the particular
application as well as the desired sensing and monitoring capabilities of the system 10.
Consequently, the present invention should not be regarded as limited to arrangements
wherein the sensing platforms 14 are identical to one another.
Referring now primarily to Figures 2-4, one embodiment of a sensing platform 14
may comprise a housing 24 sized to receive the various components and subsystems of the
sensing platform 14. In one embodiment, housing 24 may comprise a two-piece or split
housing 24 having a first half 44 and a second half 46. The first and second halves 44 and 46
of split housing 24 may define one or more respective cavities (e.g., 48 and 50) therein sized
to receive the various subsystems and components of the sensing platform 14. The first and
second halves 44 and 46 may be releasably secured to one another (e.g., via a plurality of
fasteners 52) to allow the first and second halves 44 and 46 to be readily separated, thereby
providing easy access to the various systems and components housed therein. The two-piece
arrangement of housing 24 also allows sensor platform to be readily secured to the electrical
conductor 40 of the power transmission system 38.
In addition to housing the various components and subsystems of the sensing platform
14, the housing 24 may also need to be provided with certain other features and attributes to
allow it to function well in the intended application (e.g., with the particular type of
transmission system 12 involved) and in the expected environment. For example, in an
embodiment wherein the sensing platform 14 is to be mounted to an electrical conductor 40
of an electric power transmission system 38, the housing 24 should be configured to
minimize the likelihood of corona discharge at the voltages expected in the electrical power
transmission system 38. Protection against corona discharge is particularly important wherein
the voltages involved are in the tens of kilovolt range or higher. One shape that will
minimize corona discharge comprises a generally cylindrically-shaped main body portion 54
having a pair of generally hemispherically-shaped end portions 56, 57, as best seen in Figures
2 and 3. Alternatively, other shapes are possible, as would become apparent to persons
having ordinary skill in the art after having become familiar with the teachings provided
herein. In order to further reduce the likelihood of corona discharge, any fasteners 52 used to
fasten together the two halves 44 and 46 of housing 24 should be recessed within the halves
44 and 46 so that the fasteners 52 do not protrude beyond the exterior surface 58 of housing
24, as best seen in Figure 2.
In such an application, housing 24 should also be made from an electrically
conductive material (e.g., aluminum) so that housing 24 will remain at the same electrical
potential as the electrical conductor 40. However, suitable precautions also should be taken
to prevent the housing 24 from carrying electrical current that would normally be carried by
conductor 40. One suitable precaution is to provide an insulator 60 (Figure 3) between one of
the ends (e.g., end 56) of housing 24 and the electrical conductor 40, while allowing the other
end (e.g., end 57) of housing 24 to remain in electrical contact with conductor 40. Such an
arrangement will allow the housing 24 to acquire the electrical potential on conductor 40
while preventing current from flowing through the housing 24 that may otherwise occur due
to the "skin effect" associated with electric current flow. Alternatively, other arrangements
are possible for achieving these two conditions, as would become apparent to persons having
ordinary skill in the art after having become familiar with the teachings provided herein.
As mentioned above, the sensing platform 14 may be provided with a variety of
subsystems and components in order to carry out the functional and operational aspects of the
sensing platform 14. In one embodiment, the various subsystems and components are
provided on a single printed wiring board 68 sized to be received within housing 24. Printed
wiring board 68 may be housed within the second or lower half 46 of housing 24. A cover
plate 90 may be used to secure the printed wiring board 68 within the second half 46 and to
insulate it from conductor 40, as best seen in Figures 2 and 3. Alternatively, other
arrangements are possible, as would become apparent to persons having ordinary skill in the
art after having become familiar with the teachings provided herein.
Sensing platform 14 may be provided one or more sensors 26 suitable for sensing any
of a wide range of conditions of the transmission system 12. In this regard it should be noted
that, depending on the particular type of sensor, sensor 26 may be used to sense at least one
condition of the transmission system 12 or may be used to sense at least one condition of an
environment surrounding the transmission system 12. Exemplary sensors that may be utilized
in sensing platform 14 include, but are not limited to, motion sensors (e.g., accelerometers),
acoustic sensors, temperature sensors, and optical sensors (e.g., detectors and cameras).
However, because the particular type of sensor or sensors 26 that may be utilized may depend
on the particular application and conditions to be sensed, the present invention should not be
regarded as limited to any particular type of sensor or combinations of sensors. By way of
example, in one embodiment, each sensing platform 14 is provided with three sensors 26: A
two-axis accelerometer 62, an infra-red detector 64, and a temperature sensor 66. See Figure
3. As mentioned above, the various sensors 26 may be mounted to printed wiring board 68.
Two axis accelerometer 62 detects or senses movement (e.g., acceleration) along two
different axes, which may be perpendicular to one another, although this is not required. In
addition, the accelerometer 62 should not be regarded as limited to detecting accelerations
along two axes, but could instead comprise a single-axis accelerometer, a three-axis
accelerometer, or any combination of single or multi-axis accelerometers, as may be required
to sense or detect the desired motion.
In the embodiment shown and described herein, two axis accelerometer 62 may be
used to detect motion (e.g., vibrations) of the transmission system 12, such as, for example,
vibrations caused by event 55 occurring on or near tower 42. See Figure 1. Two-axis
accelerometer 62 may comprise any of a wide range of accelerometers now known in the art
or that may be developed in the future that are, or would be, suitable for the intended
application. Consequently, the present invention should not be regarded as limited to any
particular type of accelerometer. However, by way of example, in one embodiment, the two
axis accelerometer 62 comprises an "accelerometer on a chip," such as, for example product
no. ADXL203, available from Analog Devices, Inc., of Norwood, MA. The two-axis
accelerometer 62 may be mounted to the printed wiring board 68.
The infra-red detector 64 may be used to detect light in the infra-red portion of the
electro-magnetic spectrum. Consequently, infra-red detector 64 may be used to detect objects
(e.g., persons, animals, or vehicles) or events that emit infra-red signatures. In one
embodiment, infra-red detector 64 comprises a multi-element sensor having a field of view
sufficient to encompass the desired area to be sensed. For example, in an embodiment
wherein the monitoring system is utilized to monitor an electrical power transmission system
38, it will generally be desirable to provide an infra-red detector 64 having a field of view that
is sufficiently large so that detector 64 may be used to monitor a region that includes at least
one support tower 42. Consequently, infra-red detector 64 may be used to detect the presence
of objects that may pose a threat to the integrity of the support tower 42.
Infra-red detector 64 may comprise any of a wide variety of infra-red detectors that are
known in the art or that may be developed in the future. Consequently, the present invention
should not be regarded as limited to use with any particular type of infra-red detector 64.
However, by way of example, in one embodiment, infra-red detector 64 may comprise an
infra-red detector available from PerkinElmer Optoelectronics, Inc., of Fremont, CA as
product no. LHiI 128. As mentioned above, infra-red detector 64 may be mounted on printed
wiring board 68, with a suitable lens 70 mounted to housing 24, as best seen in Figures 2 and
3. Alternatively, other arrangements are possible, as would become apparent to persons
having ordinary skill in the art after having become familiar with the teachings provided
herein.
Sensing platform 14 may also be provided with a temperature sensor 66 for
monitoring an ambient temperature, which may be desirable in certain applications. In one
embodiment, temperature sensor 66 may comprise a temperature sensor available from
Microchip Technology, Inc., of Chandler, AZ as product no. TC1047. Temperature sensor 66
may be mounted on printed wiring board 68, although other arrangements are possible.
The sensing platform 14 may also comprise a control system or processor 28
operatively associated with the sensor or sensors 26. Control system 28 receives output
signals 36 from each of the sensors 26 and produces information 20 relating to the one or
more conditions sensed by the sensors 26. Control system or processor 28 may also be
mounted to printed wiring board 68 and may comprise one or more general-purpose digital
signal processors or "computers on a chip" of the type well-known in the art and readily
commercially available. By way of example, in one embodiment, the control system 28
comprises two digital signal processors 80 and 82 that operate together to perform the
functions and operations of control system 28. The first digital signal processor 80 operates
the various sensors 26, receives the various output signals 36 produced by the sensors 26, and
analyzes the output signals 36 to produce information 20 about the sensed conditions. The
second signal processor 82 receives the information 20 from the first signal processor 80 and
operates the transceiver 34.
The processors 80 and 82 may comprise any of a wide range of processors now known
in the art or that may be developed in the future at are, or would be, suitable for the particular
application. Consequently, the present invention should not be regarded as limited to any
particular type of processor, or even combinations of processors. However, by way of
example, in one embodiment, both processors 80 and 82 may comprise processors, available
from Microchip Technology, Inc., of Chandler, AZ, as product no. PIC30F6012.
As mentioned above, it is generally desired, but not required, to provide each sensing
platform 14 with a transceiver 34 comprising a transmitter 30 and a receiver 32.
Alternatively, a receiver 32 need not be provided, depending on the functionality that is to be
provided by sensing platform 14. The transceiver 34 may be connected to a suitable antenna
84 to allow signals (e.g., information 20) to be transmitted by and received from the
transceiver 34 as radio-frequency signals. See Figure 1. Transceiver 34 may comprise any of
a wide range of transceivers known in the art and that would be suitable for the intended
application. Consequently, transceiver 34 should not be regarded as limited to any particular
type of transceiver. However, by way of example, in one embodiment, transceiver 34
comprises product no. MICRF505 transceiver available from Micrel, Inc., of San Jose, CA.
Before proceeding with the description, it should be noted that any of a wide variety
of alternative configurations and devices may be utilized to transmit the information 20. For
example, the information 20 could be transmitted along one or more components (e.g.,
electrical conductors 40) of the transmission system 12 itself. Alternatively, the information
20 need not be transmitted by radio, but could instead be transmitted by other means (e.g., by
light), as would become apparent to persons having ordinary skill in the art after having
become familiar with the teachings provided herein. Consequently, the present invention
should not be regarded as limited to the particular types of transmitters (e.g., radio-frequency
transmitters) shown and described herein.
Still referring to Figures 2-4, each sensing platform 14 may be provided with a power
conversion system 72. Power conversion system 72 allows each sensing platform 14 to be
operated by energy derived from the transmission system 12. Power conversion system 72
thereby allows the sensing platform 14 to be operated without the need to provide a separate
power source, such as a storage battery. Power conversion system 72 may comprise any of a
wide range of systems suitable for deriving energy from the particular type of transmission
system 12. Consequently, the present invention should not be regarded as limited to any
particular type of power conversion system. However, by way of example, in one
embodiment wherein the transmission system 12 comprises an electrical power transmission
system 38, power conversion system 72 comprises an inductive power converter 74.
Briefly, inductive power converter 74 may comprise a wire coil 76 (Figure 2)
positioned so that it is contained within an alternating magnetic field B produced by the
electrical power transmission system 38. In one embodiment, wire coil 76 may be wrapped
around a portion of a two-piece or split core element 86 which is configured to surround
conductor 40 when the platform 14 is mounted thereto, as best seen in Figures 2 and 3. As is
known, the alternating magnetic field B surrounding the conductor 40 will induce an
alternating current flow in wire coil 76. Inductive power converter 74 may also be provided
with suitable rectification and regulation circuitry (not shown) to convert the alternating
current in wire coil 76 into a regulated, direct current suitable for use by the various
components and systems comprising the sensing platform 14.
Generally speaking, it will be advantageous to design inductive power converter 74 so
that it will be substantially vibration-free during operation, as vibrations produced by
inductive power converter 74 would be detected by any accelerometers or motion sensors
provided on the sensing platform. Vibration-free operation can be enhanced by ensuring that
the core element 86 remains linear (i.e., does not become magnetically saturated) during
operation. Inductive power converter 74 may also be provided with one or more large
capacitors or "super" capacitors (not shown) to provide electrical power to the sensing
platform 14 for some period of time (e.g., minutes) if the current flow in the conductor 40 is
lost. Therefore, sensing platform 14 will be able to transmit information about the anomalous
condition (e.g., power loss in the conductor 40). Alternatively, other back-up power supplies
(e.g., storage batteries) could be utilized.
Referring back now to Figure 1, endpoint receiver 18 may comprise a receiver (not
shown) suitable for receiving information 20 transmitted by one or more sensing platforms
14. Endpoint receiver 18 may also be provided with a transmitter (also not shown) for
transmitting data to the various sensing platforms 14. In the embodiment shown and
described herein, the receiver and transmitter are combined into a transceiver which may be
identical to the transceiver utilized in the sensing platforms 14, thus will not be described in
further detail herein.
As mentioned, endpoint receiver 18 may be configured to operate in conjunction with
user interface system 22. Consequently, endpoint receiver 18 need not be provided with a
separate user interface system, although a user interface could be provided directly on
endpoint receiver 18. However, endpoint receiver 18 may be provided with a suitable data
interface system (also not shown) suitable for allowing endpoint receiver 18 to communicate
with user interface system 22. In an example embodiment wherein user interface system 22
comprises a general purpose programmable computer (e.g., a personal computer), the data
interface system provided on the endpoint receiver may comprise any of a wide range of data
interface systems or communication links 77 suitable for communicating with the particular
type of computer comprising the user interface system 22. Consequently, the present
invention should not be regarded as limited to any particular type of interface system.
However, by way of example, in one embodiment, the data interface system may comprise an
RS-232 data interface system.
In this regard it should be noted that alternative variations are possible for allowing
endpoint receiver 18 to communicate with user-interface system 22 via communication link
77. For example, in an alternate embodiment, communication link 77 may comprise an
existing communication system (e.g., telephone lines, micro-wave relay stations, fiber-optic
lines, etc.) located with or nearby the transmission system 12. Thus, information may be
transmitted between endpoint receiver 18 and user interface system 22 via the existing
communication system. Such an arrangement may allow one or more endpoint receivers 18
to be conveniently mounted on one or more support towers 42 (Figure 1) and tied-in to the
existing communication system (e.g. telephone line), thereby allowing the user interface
system 22 to be provided at any convenient location.
Still referring to Figure 1, user interface system 22 may comprise any of a wide range
of systems and devices known in the art or that may be developed in the future that are or
would be suitable for allowing the desired degree of user interface with monitoring system
10. In the embodiment shown and described herein, the user interface system 22 may
comprise a general purpose programmable computer system, such as a personal computer
having a display 78 and a keyboard 88. Information 20 received by endpoint receiver 18 may
be displayed on display 78 of user interface 22. The keyboard 88 may be utilized to
manipulate the information 20 and/or change the layout of the information 20 provided on
display system 78. In addition, and as will be described in greater detail below, user interface
system 22 may be used to send data and/or programming information or modifications back
to the sensing platforms 14 via the transceiver provided in the endpoint receiver 18.
The monitoring system 10 may be operated as follows to sense at least one condition
of the transmission system 12. As was previously described, the various sensing platforms 14
may be used to sense one or more conditions of the transmission system 12, ranging from, for
example, vibrations of the transmission system 12 sensed by the accelerometer 62, infra-red
light emitted by objects or persons within the sensing area of infra-red sensor 64, and/or the
ambient temperature, as sensed by the temperature sensor 66. The output signal(s) 36 from
the sensor or sensors 26 are received by the control system or processor 28. While the control
system or processor 28 may simply pass-on the signals to the transmitter 30 without
evaluation or analysis (whereupon they may be transmitted as information 20), it will
generally be more preferable for the control system or processor 28 to first evaluate or
analyze the output signals 36 in order to determine whether the sensed conditions are normal
or anomalous. In this way, only information 20 that relates to an anomalous condition need
be transmitted.
A data processing routine 92 that may be utilized by the control system 28 to evaluate
the output signals 36 is illustrated in Figure 5. In one embodiment, the output signal 36 from
the sensors 26 may be pre-filtered at step 94 in order to remove unwanted or undesirable
components (e.g., 60 Hz noise and harmonics thereof) from the output signals 36 in order to
simplify subsequent processing and analysis. The pre-filtering process 94 may involve the
use of one or more analog or digital filters, such as high-pass, low-pass, or band-pass filters.
The particular characteristics of the pre-filter 94 may vary depending on the particular types
of output signals 36 produced by the various sensors 26 and would be easily selected by
persons having ordinary skill in the art after having become familiar with the teachings
provided herein and after considering the particular sensors 26 to be utilized and noise
components to be removed. Consequently, the particular types of filters that may be utilized
in the pre-filtering process 94 will not be described in further detail herein.
After suitable pre-filtering, filtered signals may then be digitized at step 96. Of
course, such digitization need not be performed if the signals already comprise digital, as
opposed to analog, signals. The digitized signals may then be processed by any of a wide
variety of digital signal processing techniques in order to produce signals that may be more
conducive to the subsequent analysis process 104. The particular digital signal processing
techniques will depend on the type of analysis to be performed, i.e., to determine whether the
signals 36 are indicative of a normal condition or an anomalous condition, as well as on the
particular nature of the output signals, e.g., whether the output signals 36 were generated by
an accelerometer (e.g. 62), an infra-red sensor (e.g., 64), or by a temperature sensor (e.g., 66).
For example, an output signal from a temperature sensor (e.g., 66) will require much less
processing than an output signal generated by an accelerometer (e.g. 62) or an infra-red sensor
(e.g., 64), in order to determine whether the signal is regarded as indicative of a normal
condition or an anomalous condition. Consequently, the present invention should not be
regarded as limited to any particular digital signal processing technique or series of signal
processing techniques. However, by way of example, in one embodiment, a subsequent
digital signal processing technique may comprise a fast Fourier transfer (FFT) step 98, in
which the output signals are converted from the time domain into the frequency domain. A
subsequent filtering step 102 may then be conducted to filter or remove unwanted
components from the processed signal.
After the output signals 36 have been digitized, processed, and filtered, as described
above, they may then be analyzed at step 104. As mentioned above, the analysis process 104
may be performed to determine whether the output signal 36 produced by the sensor 26 is
indicative of a normal condition or an anomalous condition. One way to make such a
determination is to compare the output signal with a threshold value or values associated with
a normal condition. If the output signal is outside the threshold value or values, then the
sensed condition is regarded as anomalous. The particular threshold value or values that may
be utilized will depend on the particular sensor output signal to be analyzed as well as on the
particular type of transmission system 12 and environment. In certain circumstances, it will
be sufficient to simply compare the processed output signal with the corresponding threshold
value or values established for the particular sensor. However, in other cases, it may be
necessary to additional process the data before making the comparison.
For example, and with reference now to Figure 6, a better determination as to whether
data from a motion sensor (e.g., accelerometers 62) are indicative of a normal condition or an
anomalous condition may require the power spectrum of the signal to be computed, as
illustrated in step 106. The impulse energy of the power spectrum may then be computed at
step 108. The computed impulse energy may then be compared with a corresponding
threshold value or values at step 110.
Before proceeding with the description, it should be noted that the threshold value or
values may be developed from testing associated with the particular type of transmission
system 12, as well as on the particular type of sensor. For example, in the case of sensing
vibrations of an electrical power transmission system 38 that may be caused by a potentially
threatening event 55 (e.g., an explosion, sawing, hammering, or climbing) on one or more
support towers 42, suitable threshold values may be determined by measuring accelerations
detected by one or more sensing platforms 14 mounted on the electrical conductors 40 in
response to simulated events. The resulting responses may then be used to establish
corresponding threshold values.
While the accelerations themselves could be analyzed (i.e., as they are detected in the
time domain), it will generally be easier to perform the analysis if the acceleration data is
converted into the frequency domain (e.g., via fast-Fourier transform process 98, Figure 5).
The power spectrum and impulse energy can be calculated (at steps 106 and 108,
respectively) by known techniques. In this way, threshold values associated with potentially
threatening activities can be determined and programmed into the control system 28 (Figure
4). Then, if similar signals are detected (e.g., as determined in step 110), then a determination
can be made at step 112 as to whether the signals are indicative of a normal condition (e.g.,
vibrations due to wind) or an anomalous condition (e.g., sawing or hammering occurring on
one or more support towers 42). If an anomalous condition is determined, the control system
28 may then operate transmitter 30 to transmit information 20 relating to the anomalous
condition. That is, the analysis process 104 can report the anomalous condition at step 114.
The analysis process 104 may also be configured to send a report (i.e., transmit information
20) when the condition clears at step 116.
As mentioned, the information 20 provided in the report (e.g., at step 114) transmitted
by the sensing platform 14 may comprise any of a wide range of information. For example,
in addition to merely reporting the detection of an anomalous condition, information 20 may
contain processed data (e.g., the calculated impulse energy), as well as unprocessed or raw
data produced by the sensors 26. The information 20 may also include data from other
sensors 26 even if the data produced thereby was determined to be indicative of a normal
condition. Of course, the information 20 may also contain the identity and/or location of the
sensing platform 14 that detected the anomalous condition. In short, information 20 may
comprise any of a wide variety of information that may be useful to a system operator if an
anomalous condition is detected.
The information 20 transmitted by the sensing platform 14 that detected the
anomalous condition may be relayed by one or more other sensing platforms 14 provided on
the transmission system 12 before being received by endpoint receiver 18, as already
described. Endpoint receiver 18 may operate in conjunction with user interface 22 in order to
provide the information 20 in any desired form. For example, upon initial receipt of
information 20 relating to an anomalous condition, user interface 22 may be programmed to
provide a visual and/or aural alarm. The identification and location of the particular sensing
platform or platforms 14 that detected the anomalous condition may also be provided, along
with processed data and/or raw data. Any other information may be provided that would be
deemed useful to a system operator in evaluating the seriousness of the situation. For
example, if the sensing platform 14 is provided with an optical sensor (e.g., a camera), image
data from the camera may be provided to allow a user to perhaps determine the cause of the
anomalous condition.
As described earlier, the user interface 22 and endpoint receiver 18 may also be used
to transmit information to the various sensing platforms 14. For example, in response to
receiving information 20 indicative of the detection of an anomalous condition, the user may
instruct the user interface 22 to send a signal to the sensing platform 14 requesting additional
data relating to the detected condition. The user interface 22 could also be used to re-program
one or more of the other sensing platforms 14 to, for example, change the threshold levels.
Such re-programming could allow the anomalous condition to be determined with more
certainty by determining whether other sensing platforms 14 detected similar data. Of course,
such re-programming of the sensing platforms 14 need not be done upon the detection of an
anomalous condition, but could be done at any time. Many other variations are possible, as
would become apparent to persons having ordinary skill in the art after having become
familiar with the teachings provided herein. Consequently, the present invention should not
be regarded as limited to the particular programming sequences and operational scenarios
shown and described herein.
Having herein set forth preferred embodiments of the present invention, it is
anticipated that suitable modifications can be made thereto which will nonetheless remain
within the scope of the invention. The invention shall therefore only be construed in
accordance with the following claims:
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