TECHNICAL FIELD
Embodiments herein relate generally to signal processing and more
particularly to compressing content in high-frequency signals.
BACKGROUND OF THE INVENTION
Various measurement systems and equipment can capture content from highfrequency
signals. Processing such signals, however, can require a dedicated and
specialized infrastructure including special wiring, high-speed data acquisition
devices, and large storage devices. Such an infrastructure can be costly to build and
maintain each time high-frequency signals require processing. More conventional
infrastructures that may be unable to process high-frequency signals have not been
fully leveraged to provide a more diverse, cost-effective alternative.
BRIEF DESCRIPTION OF THE INVENTION
Some or all of the above needs andlor problems may be addressed by certain
embodiments of the invention. Certain embodiments may include systems, methods,
and apparatuses for compressing high-frequency signals. According to one
embodiment, there is disclosed an apparatus including: a switch, configured to receive
at least one compressed signal, wherein the at least one compressed signal is created
in part by compressing at least one measured signal; a modulator, coupled to the
switch, configured to modulate the at least one compressed signal; a filter, coupled to
the modulator, configured to filter the at least one measured signal; at least one
memory, coupled to the modulator, configured to store the at least one compressed
signal; and a control interface, coupled to at least one of the switch, the modulator, the
filter, or the at least one memory, configured to control at least one of the switch, the
modulator, the filter, or the at least one memory to compress the at least one measured
signal.
According to another embodiment, there is disclosed a system including at
least one memory that stores computer-executable instructions, and at least one
processor configured to access the at least one memory, wherein the at least one
processor is configured to execute the computer-executable instructions to receive a
signal, correct the signal, determine a number of samples to be collected from the
corrected signal, store a maximum value of the corrected signal for each of a plurality
of packets, and generate a waveform based at least in part on the maximum value
stored for each of the plurality of packets.
According to a further embodiment, there is disclosed a method for
receiving, from a monitored machine, a high-frequency signal of at least
approximately 100 kHz, correcting the high-frequency signal by recording only a
predefined portion of the high-frequency signal, determining a number of samples to
be collected from the corrected high-frequency signal, dividing the high-frequency
signal into a plurality of packets based at least in part on the number of samples,
storing a maximum value of the corrected high-frequency signal for each of the
plurality of packets, and generating a waveform based at least in part on the maximum
value stored for each of the plurality of packets.
Other embodiments, systems, methods, apparatuses, aspects, and features of
the invention will become apparent to those skilled in the art fiom the following
detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE FIGURES
The detailed description is set forth with reference to the accompanying
drawings, which are not necessarily drawn to scale. The use of the same reference
numbers in different figures indicates similar or identical items.
FIG. 1 is a block diagram of an apparatus including, but not limited to, signal
conditioning components for compressing high-frequency signals, according to one
embodiment.
FIG. 2a is a graphical illustration of a high-frequency signal that is sampled
according to certain embodiments herein.
FIG. 2b is a graphical illustration of an exemplary waveform that may result
from compressing a high-frequency signal, according to one embodiment.
FIG. 3 is a block diagram of an exemplary computing environment for
compressing high-frequency signals, according to one embodiment.
FIG. 4 is a flow diagram illustrating details of a method for compressing
high-frequency signals, according to one embodiment.
DETAILED DESCRIPTION OF THE INVENTION
Illustrative embodiments will now be described more fully hereinafter with
reference to the accompanying drawings, in which some, but not all embodiments of
the invention are shown. The invention may be embodied in many different forms
and should not be construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will satisfy applicable legal
requirements.
Illustrative embodiments of the invention are directed to, among other things,
compression of high-frequency signals. As used herein, a signal may be considered a
high-frequency signal if it is greater than or equal to about 100 KHz. Compressing a
high-frequency signal can refer generally to converting the high-frequency signal to a
lower frequency signal, i.e., a signal lower than about 100 KHz. Certain
embodiments herein are directed to compressing high-frequency signals into lower
frequency signals so that they can be used by infrastructures that can process lower
frequency signals but not high-frequency signals, i.e., lower frequency infrastructures
as used herein. For example, certain inputloutput (10) devices, such as monitors and
wires connecting such devices to various high-frequency systems, may be unable to
receive and process high-frequency signals in their original form.
Compression of high-frequency signals can be performed using various
systems and components in certain embodiments herein. As an overview, a computer
system executing computer-instructions may compress a high-frequency signal. The
computer system can receive a high-frequency signal, such as an ultrasonic wave, and
correct the signal for fiuther processing. For example, the high-frequency signal can
be amplified to increase the resolution of the high-frequency signal. The computer
4
system may also filter the high-frequency signal to keep data for certain frequencies.
The signal can be further rectified so that peak levels along the sinusoidal waveform
representing the high-frequency signal can be captured, according to one embodiment.
In one embodiment, after the high-frequency signal has been corrected, the
computer system can determine a rate at which to sample the high-frequency signal.
A maximum value for each sample taken can be stored and used to create an
amplitude modulated waveform that may represent the original high-frequency signal
as a lower frequency signal. The generated waveform can be sent over a field wire to
an I0 device, both in a lower frequency infrastructure, where it can be processed or
analyzed. Prior to compressing the high-frequency signal as described above, the
field wire and I 0 device would have been unable to handle the high-frequency signal,
according to certain embodiments. The computer system can also combine multiple,
compressed high-frequency signals into a single lower frequency signal and send the
combined signal to a lower frequency infrastructure. Certain embodiments herein
also describe an apparatus that can also implement the compression of high-frequency
signals described above.
The technical effects of certain embodiments herein may be reduced costs
associated with processing high-frequency signals in the way that relatively expensive
infrastructures used to process such signals may not be necessary for all situations in
which high-frequency signals need to be processed.
FIG. 1 depicts an apparatus that can be used to compress a high-frequency
signal, according to one embodiment. The apparatus can include, but is not limited to,
a signal conditioner 104, and an I 0 module 120. In one embodiment, the apparatus
can be an analog-to-digital (AD) converter. The signal conditioner 104 can receive
high-frequency signals from one or more sensors 102. The one or more sensors 102
can be associated with conditioning monitoring systems on rotating and reciprocating
equipment, or other measurement systems equipment, as non-limiting examples.
High-frequency signals can also be received from various other types of equipment
that may generate high-frequency signals. In one embodiment, the apparatus can
include, but is not limited to, components that may correct a high-frequency, process
the corrected signal, and output a waveform in a lower frequency that may be
representative of the original, high-frequency signal.
The signal conditioner 104 can include, but is not limited to, a maximum
detect and hold control interface 112. In one embodiment, the maximum detect and
hold control interface 112 can be coupled to one or more of a switch, a modulator, a
filter, and at least one memory. Such an interface can control each of these
components to compress one or more signals, such as signals received from
measurement equipment, i.e., measured signals. In one aspect of an embodiment, the
measured signal can be a high-frequency signal of at least about 100 KHz.
One or more pre-amplifiers 106, filters 108, and signal rectifiers 110 can be
used to correct the measured signal, in one embodiment. According to this
embodiment, the pre-amps 106 can amplify the measured signal to increase the
resolution of the measured signal by, for example, increasing the signal-to-noise ratio.
A filter 108 can be coupled to the modulator and configured to filter out invalid or
unwanted data points from the measured signal. Exemplary filters can include, but
are not limited to, a bandpass filter and a decimation bandwidth filter. The signal
rectifier 110 can be configured to correct the measured signal by recording only a
predefined portion of the signal, in one embodiment. In one aspect of the
embodiment, the predefined portion of the measured signal can be a positive portion
of the signal. The signal rectifier 11 0 can record other portions of a signal to correct
the signal or otherwise prepare the measured signal for compression, in other
embodiments.
In certain embodiments, the maximum detect and hold control interface 112
can implement a computer algorithm to compress a measured signal, such as a
corrected high-frequency signal. In one embodiment, the computer algorithm can be
implemented by a digital signal processor (DSP), which can receive computerexecutable
instructions for performing the compression in its firmware. The
maximum detect and hold control interface 112 can determine a rate for acquiring
digital samples from the corrected signal. A primary factor in such a determination
can be the frequency at which a signal is desired to be modulated. The modulated
frequency can depend on the infrastructure or equipment that may receive and process
6
the modulated signal. For example, to process a signal modulated at about 20 KHz
that may be representative of an original, high-frequency approximate 454 KHz
signal, about twenty-three samples would need to be taken. The number of samples
can be determined by dividing the original, high-frequency signal (about 454 KHz) by
the desired frequency of the modulated signal (about 20 Hz).
Upon determining the number of samples to acquire, according to one
embodiment, the maximum detect and hold control interface 112 can acquire the
samples. The lighter-shaded portion of the exemplary signal in FIG. 2a represents the
acquired samples, according to one example. In one embodiment, the lighter-shaded
portion can have a length equal to the inverse of the sampling frequency, e.g., 20
KHz, times the number of samples, e.g., twenty-three. The maximum detect and hold
control interface 112 can also store the acquired samples in a memory, which can be
coupled to the modulator and configured to store the compressed signal. In one
aspect of an embodiment, the maximum value of the acquired digital samples can be
stored. In another aspect, the maximum value of the corrected signal for each of a
plurality of packets can be stored.
The compressed signal, for example the compressed signal shown in FIG 2b,
can be further processed to make it suitable for receipt by a lower frequency
infrastructure. Such an infrastructure may, in certain embodiments, require an analog
signal. In one embodiment, the maximum detect and hold control interface 112 can
"fill-in" the area underneath the compressed signal such that the compressed signal
can include an amplitude modulated sinusoidal waveform, in one aspect of an
embodiment. Such a waveform can be generated by the maximum detect and hold
control interface 112 performing certain calculations on data from the compressed
signal. The calculations can include, but are not limited to, determining a modulation
for the waveform based on the sampling frequency. An exemplary waveform that can
result from the calculations is shown in FIG. 2b. Such a waveform may be without
high-frequency content and therefore can be used in certain lower frequency
infrastructures.
In one embodiment, the algorithm implemented by the control interface 112
may be implemented in Microsoft@ Visual Basic@ for Applications (VBA), and the
data may be stored in a format compatible with VBA, such as data exported from
Microsoft@ Excel@ in Comma Separated Values (CSV) format. In other
embodiments, various other programming languages and data formats can be used to
implement the algorithm.
In one embodiment, the maximum detect and hold control interface 112 can
also be configured to divide the compressed signal into at least two divisions that can
be based at least in part on the determined number of samples collected from the
corrected signal. In one aspect of an embodiment, an amount of the plurality of
packets may be based at least in part on the at least two divisions. The maximum
detect and hold control interface 112 can be further configured to store or output the
generated waveform. For example, the generated waveform may be passed through a
field wire to an I 0 module 120 in a lower frequency infrastructure by a modulator
114, which can be coupled to the switch and configured to modulate the compressed
signal, e.g., in its sinusoidal wave form. The switch 116 can be configured to receive
at least one compressed signal, which, according to one embodiment, can be created
by compressing one or more measured signals. In certain embodiments, the switch
116 can be a multiple-input, single output switch, such as a multiplexing switch,
which can combine compressed signals into a single signal before it is transmitted to
an I0 module 120 in a lower frequency infrastructure by the modulator 114. The
filters 122 in the I 0 module 120 may be required to separate the combined signal at
the I0 module 122 before it can be processed, in some embodiments.
In certain embodiments, the process of compressing a high-frequency signal
may introduce a timing error which reflects a lag between the compressed signal and
the measured, high-frequency signal. In the above example, a timing error of about
6.3x10-~s econds may be introduced ((23 samples * 1.25)/454 KHz, where 1.25 is a
factor and 454 KHz is the approximate frequency of the high-frequency signal.
According to certain embodiments, such an error or less can be acceptable.
FIG. 3 depicts a block diagram of an exemplary computing environment for
compressing a high-frequency signal. The computing environment 300 can include a
computing device, which can include a processor 304 capable of communicating with
a memory 302. The processor 304 can be implemented as appropriate in hardware,
software, firmware, or combinations thereof. Software or firmware implementations
of the processor 304 may include computer-executable or machine-executable
instructions written in any suitable programming language to perform the various
hnctions described. Examples of computing devices may include a personal
computer, mainframe, web server, mobile device, or any processor-based device
capable of executing instructions to perform the fimctions described in embodiments
herein.
A memory 302 can store program instructions that are loadable and
executable on the processor 304, as well as data generated during the execution of
these programs. Depending on the configuration and type of computing environment
300, a memory 302 may be volatile (such as random access memory (RAM)) and/or
non-volatile (such as read-only memory (ROM), flash memory, etc.). The computer
device may also include additional removable storage 306 and/or non-removable
storage 308 including, but not limited to, magnetic storage, optical disks, andlor tape
storage. The disk drives and their associated computer-readable media may provide
non-volatile storage of computer-readable instructions, data structures, program
modules, and other data for the computing devices. In some implementations, the
memory 302 may include multiple different types of memory, such as static random
access memory (SRAM), dynamic random access memory (DRAM), or ROM.
The memory 302, removable storage 306, and non-removable storage 308
are all examples of computer-readable storage media. For example, computerreadable
storage media may include volatile and non-volatile, removable and nonremovable
media implemented in any method or technology for storage of
information such as computer-readable instructions, data structures, program modules
or other data. Additional types of computer storage media that may be present
include, but are not limited to, programmable random access memory (PRAM),
SRAM, DRAM, RAM, ROM, electrically erasable programmable read-only memory
(EEPROM), flash memory or other memory technology, compact disc read-only
memory (CD-ROM), digital versatile discs (DVD) or other optical storage, magnetic
cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or
any other medium which can be used to store the desired information and which can
be accessed by the computer device. Combinations of any of the above should also be
included within the scope of computer-readable media.
In other embodiments, however, computer-readable communication media
may include computer-readable instructions, program modules, or other data
transmitted within a data signal, such as a camer wave, or other transmission. As
used herein, however, computer-readable storage media does not include computerreadable
communication media.
The computing environment 300 may also include one or more
communication connections 3 10. In one embodiment, the connections 3 10 can allow
the computer device to receive data from one or more sensors that receive content in
high-frequency signals. The connection between the computer device and equipment
may be wired or wireless, according to various embodiments. The computing
environment 300 can also include one or more input devices 3 12, such as a keyboard,
mouse, pen, voice input device, and touch input device. It may also include one or
more output devices 3 14, such as a display, printer, and speakers.
Turning to the contents of the memory 302 in more detail, the memory 302
can include, but is not limited to, an operating system 316 and one or more
application programs or services for implementing the features and aspects disclosed
herein, including a signal receiving module 318, a signal correction module 320, a
sample size determination module 322, a maximum value storing module 324, and a
wave generation module 326.
The signal receiving module 318 can receive a signal, such as a highfrequency
signal of at least about 100 KHz, in one aspect of an embodiment. The
signal can be corrected by the signal correction module 320. Correction of the signal
can include amplifying the signal to increase the resolution of the signal. The
amplification can be similar to that performed by the pre-amps 106 in FIG 1
described above. Correction of a signal can also include filtering the signal to remove
invalid or unwanted data points. The filtering can be similar to that performed by the
filter 108, according to one embodiment. Correction of the high-frequency signal can
further include recording only a predefined portion of the signal, in similar fashion to
that performed by the signal rectifier 110 in one embodiment. In one aspect of the
10
embodiment, the predefined portion of the signal can be the positive portion of the
signal.
Upon correcting the signal, the sample size determination module 322 can
determine a number of samples to be collected from the corrected signal. In one
embodiment, the number of samples can be determined based on a desired frequency
at which to modulate the signal. In one embodiment, the sample size determination
module 322 can also divide the signal into at least two divisions that can be based at
least in part on the determined number of samples that may be collected from the
corrected signal.
The maximum value storing module 324 can store the corrected signal in a
memory, for example. According to various embodiments, different representations
of the signal can be stored. In one embodiment, the maximum value of the corrected
signal for a plurality of packets can be stored. An amount of the plurality of packets
can be based on the at least two divisions of the signal, in one aspect of an
embodiment. The maximum value for the plurality of packets can be used to generate
a waveform, e.g., an amplitude modulated sinusoidal waveform generated by the
waveform generation module 326. The waveform generation module 326 can also
store andlor output the generated waveform, in one aspect of an embodiment.
While the embodiment in FIG 3 describes a computer device with a memory
302 including various modules, one will recognize that certain functionality
associated with the computer device can be distributed to any number and
combination of computer or processor-based devices in accordance with other
embodiments. Various instructions, methods, and techniques described herein may be
considered in the general context of computer-executable instructions, such as
program modules, executed by one or more computers or other devices. Generally,
program modules include routines, programs, objects, components, data structures,
etc., for performing particular tasks or implementing particular abstract data types.
These program modules and the like may be executed as native code or may be
downloaded and executed, such as in a virtual machine or other just-in-time
compilation execution environments. Typically, the functionality of the program
modules may be combined or distributed as desired in various embodiments. An
implementation of these modules and techniques may be stored on some form of
computer-readable storage media.
FIG. 4 is an exemplary flow diagram illustrating details of a method for
compressing a high-frequency signal. In one example, a computing device can
perform any, some, or all of the operations of process 400. The process 400 is
illustrated as a logical flow diagram, in which each operation represents a sequence of
operations that can be implemented in hardware, software, or a combination thereof.
In the context of software, the operations can represent computer-executable
instructions stored on one or more computer-readable storage media that, when
executed by one or more processors, perform the recited operations. Generally,
computer-executable instructions can include routines, programs, objects,
components, data structures, and the like that perform particular functions or
implement particular abstract data types. The order in which the operations are
described is not intended to be construed as a limitation, and any number of the
described operations can be combined in any order andlor in parallel to implement the
process.
In this particular implementation, the process 400 can begin at block 402,
where a high-frequency signal can be received. In one embodiment, the highfrequency
signal can be received from one or more sensors 102 by a signal
conditioner 104, as shown in FIG 1. A high-frequency signal can also be received by
the signal receiving module 318 in FIG. 3. The high-frequency signal can be
corrected by recording only a predefined portion of the high-frequency signal, such as
the positive portion of the signal as noted above, at block 404. Such correction can be
performed by one or more of the pre-amps 106, the filters 108, or the signal rectifiers
110, as illustrated and described in association with FIG. 1. The correction can also be
performed by the signal correction module 320 illustrated in FIG. 3, in one
embodiment.
A sample size for collecting a number of samples from the high-frequency
signal, e.g., the corrected high-frequency signal, can be determined at block 406. The
signal can also be divided into packets at block 408, and the maximum value of each
of the packets can be stored at block 410. In one embodiment, the sample size
determination, division of the signal into packets, and storing of the maximum value
of the packets can be performed by the maximum detect and hold control interface
112, as illustrated and described in association with FIG. 1. In another embodiment,
each of these processes can also be performed by the sample size determination
module 322, as illustrated and described in association with FIG 3.
A waveform can be generated at block 412. The waveform can be a lower
frequency representation of the original, high-frequency signal without the highfrequency
content. The generated waveform can be stored at block 414 and output at
block 416. In one embodiment, the waveform can be generated, stored, and output by
the maximum detect and hold control interface 112 as illustrated and described in
association with FIG. 1. In another embodiment, each of these processes can be
performed by the wave generation module 326, as illustrated and described in
association with FIG. 3.
Illustrative systems and methods for the compression of high-frequency
signals are described above. Some or all of these systems and methods may, but need
not, be implemented at least partially by configurations such as those shown in FIGS.
1 and 3. It should be understood that certain acts in the methods may be rearranged,
modified, andlor omitted entirely, depending on the circumstances. Also, any of the
acts described above with respect to any method may be implemented by any number
of processors or other computing devices based on instructions stored on one or more
computer-readable storage media.
Parts List for:
100 - System
102 - Sensor(s)
104 - Signal Conditioner
106 - Pre-Amp(s)
108 - Filter(s)
110 - Signal Rectifier(s)
1 12 - Maximum Detect & Hold Control Interface(s)
1 14 - Modulator
120 - VO Module
122 - Filter
300 - Computer Environment
302 - Memory
304 - Processor(s)
306 - Removable Storage
308 - Non-Removable Storage
3 10 - Communication Connection(s)
3 12 - Input Device(s)
3 14 - Output Device(s)
3 16 - Operating System
3 18 - Signal Receiving Module
320 - Signal Correction Module
322 - Sample Size Determination Module
325 - Maximum Value Storing Module
326 - Wave Generation Module
400 - Process
402 - Block
404 - Block
406 - Block
408 - Block
410 - Block
4 12 - Block
414 -Block
416 - Block

WE CLAIM:
1. An apparatus, comprising:
a switch, configured to receive at least one compressed signal, wherein the at
least one compressed signal is created in part by compressing at least one measured
signal;
a modulator, coupled to the switch, configured to modulate the at least one
compressed signal;
a filter, coupled to the modulator, configured to filter the at least one measured
signal;
at least one memory, coupled to the modulator, configured to store the at least
one compressed signal; and
a control interface, coupled to at least one of the switch, the modulator, the
filter, or the at least one memory, configured to:
control at least one of the switch, the modulator, the filter, or the at
least one memory to compress the at least one measured signal.
2. The apparatus of claim 1, wherein the at least one measured signal is a highfrequency
signal of at least approximately 100 kHz.
3. The apparatus of claim 1, wherein a signal rectifier is further configured to
correct the at least one measured signal by recording only a predefined portion of the
at least one measured signal.
4. The apparatus of claim 3, wherein the predefined portion of the at least one
measured signal is a positive portion of the signal.
5. The apparatus of claim 1, wherein the control interface is further configured to
divide the at least one compressed signal into at least two divisions based at least in
part on a determined number of samples to be collected from the corrected signal.
6. The apparatus of claim 5, wherein an amount of a plurality of packets is based
at least in part on the at least two divisions.
15
7. The apparatus of claim 1, wherein the at least one compressed signal
comprises an amplitude modulated sinusoidal waveform.
8. The apparatus of claim 1, wherein the control interface is further configured to
at least one of store or output a waveform representing the at least one compressed
signal.
9. A system, comprising:
at least one memory that stores computer-executable instructions; and
at least one processor configured to access the at least one memory, wherein
the at least one processor is configured to execute the computer-executable
instructions to:
receive a signal;
correct the signal;
determine a number of samples to be collected from the corrected
signal;
store a maximum value of the corrected signal for each of a plurality of
packets; and
generate a waveform based at least in part on the maximum value
stored for each of the plurality of packets.
10. The system of claim 9, wherein the signal is a high-frequency signal of at least
approximately 100 kHz.
1 1. The system of claim 9, wherein the at least one processor is further configured
to execute the computer-executable instructions to correct the signal by recording
only a predefined portion of the signal.
12. The system of claim 1 1, wherein the predefined portion of the signal is a
positive portion of the signal.
13. The system of claim 9, wherein the at least one processor is further configured
to execute the computer-executable instructions to divide the corrected signal into at
least two divisions based at least in part on the determined number of samples to be
collected from the corrected signal.
14. The system of claim 13, wherein an amount of the plurality of packets is based
at least in part on the at least two divisions.
15. The system of claim 9, wherein the waveform comprises an amplitude
modulated sinusoidal waveform.
16. The system of claim 9, wherein the at least one processor is further configured
to execute the computer-executable instructions to at least one of store or output the
generated waveform.
17. A method, comprising:
receiving, from a monitored machine, a high-frequency signal of at least
approximately 100 kHz;
correcting the high-frequency signal by recording only a predefined portion of
the high-frequency signal;
determining a number of samples to be collected from the corrected highfrequency
signal;
dividing the high-frequency signal into a plurality of packets based at least in
part on the number of samples;
storing a maximum value of the corrected high-frequency signal for each of
the plurality of packets; and
generating a waveform based at least in part on the maximum value stored for
each of the plurality of packets.
18. The method of claim 17, wherein the predefined portion of the signal is a
positive portion of the signal.
19. The method of claim 17, wherein the waveform comprises an amplitude
modulated sinusoidal waveform.
20. The method of claim 17, further comprising at least one of storing or
outputting the generated waveform.