United States Patent 55
`5,808,903
`[11] Patent Number:
`
`[45] Date of Patent: Sep. 15, 1998
`Schiltz et al.
`
`US005808903A
`
`[54]
`
`PORTABLE, SELF-CONTAINED DATA
`COLLECTION SYSTEMS AND METHODS
`
`[75]
`
`Inventors: Richard L. Schiltz, Hamilton, Ohio;
`Andrew J. Bates, Somerset, England;
`Jeffery P. Watkins, Cincinnati, Ohio
`
`Assignee: Entek Scientific Corporation,
`Cincinnati, Ohio
`
`Appl. No.: 526,981
`
`Filed:
`
`Sep. 12, 1995
`
`Tint, C18 ecccccccsesssscesseessssesseessseeesseess GO01H 11/00
`US, Cle cece 364/508; 364/566; 364/709.09;
`340/683; 73/570; 73/602
`Field of Search o....c.cccccccceeeeee 364/508, 507,
`364/566, 550, 551.01-551.02, 576, 479.19,
`709.09, 708.1, 709.01, 413.02-413.06,
`709.1, 709.11; 73/659, 660, 602, 579, 570;
`434/266; 128/670, 700, 715, 701, 739;
`381/51, 56, 57; 369/64, 63; 340/679, 680,
`683, 682
`
`OTHER PUBLICATIONS
`
`“Maintenance Products and Maintenance Matters of General
`
`Interest”, Maintenance, Jan./Feb. 1995, pp. 31-32.
`
`Pioneer Hill Software brochure entitled “Turn your Multi-
`media PC into a Powerful Spectral Analysis Workstation,”
`No Date.
`
`(List continued on next page.)
`
`Primary Examiner—EmanuelT. Voeltz
`Assistant Examiner—Hal P. Wachsman
`Attorney, Agent, or Firm—Bell Seltzer Intellectual Property
`Law Group of Alston & Bird LLP
`
`[57]
`
`ABSTRACT
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`A portable self-contained data collection system for mea-
`suring and collecting vibration data from machines includes
`an accelerometer which is coupled to the analog input of a
`data acquisition card. The data acquisition card samples and
`digitizes the analog signal to produce a time domain digital
`signal. The data acquisition card output is coupled to a
`battery-powered portable computer. The battery-powered
`portable computer includes a database having machineiden-
`tifications and associated measurement parameters. The por-
`table computer processes the time domain digital signal
`5/1973) Petrovick ....ciceeeesseseeeeeeneeee 434/266
`3,732,631
`according to the measurement parameters associated with a
`
`3,762,397 10/1973 Cage coccccccseccsecceseseseenees 128/700
`6/1985 Canadaet al. oc
`eeeeeeeeeeee 73/660
`4,520,674
`selected machine identification, and produces a frequency
`
`
`4,612,620 9/1986 Daviseal.......... . 364/551.01
`
`
`domain digital signal by performing a Fast Fourier Trans-
`4,885,707 12/1989 Nicholet al. oceans 73/660
`
`form and other digital signal processing operations. The
`w. 381/51
`5,056,145
`10/1991 Yamamotoetal.
`
`frequency domain signal is also analyzed in the portable
`6/1992 Gilbert et al. oe
`eee 364/508
`5,122,970
`
`computer to produce predictive maintenance information. A
`5,210,704
`5/1993 Husseiny ............0..
`. 364/551.01
`power supply for supplying power to the accelerometer is
`5,251,151
`10/1993 Demjanenkoet al... 364/550
`
`also included. The accelerometer power supply electrically
`5,285,437
`2/1994 Yokota et al. cee
`eeeeeeeeeeeeee 369/64
`and mechanically couples the accelerometer to the data
`5,497,464
`3/1996 Yeh oe
`« 364/708.1
`5,541,876
`7/1996 Taheie et al. cesses.ven 364/566
`acquisition card.
`It supplies power to the accelerometer
`when the data acquisition card is activated.
`FOREIGN PATENT DOCUMENTS
`
`07253352 10/1995
`
`Japan .
`
`12 Claims, 7 Drawing Sheets
`
`
`
`
`
`
`
`APPLE 1106
`
`APPLE 1106
`
`1
`
`

`

`5,808,903
`Page 2
`
`OTHER PUBLICATIONS
`
`CSIbrochure entitled “WAVEPAK An FFT Signal Analyzer
`Inside Your IBM PC,” No Date.
`National Instruments brochure entitled “Instrumentation
`
`Reference and Catalogue”, No Data.
`Communication Automation & Control, Inc. brochure for
`“PCMCIA TI TMS320C32 Bulletdsp,” No date.
`SAIC brochure for “Machinexpert Portable Data Analyzer.”,
`Jul. 1995.
`
`Vibration Test Systems brochure for “PLANTMAN™,”
`Vibrations, vol. II, No. 2 Jun. 1995).
`
`Inc. brochure for “PCMCIA 16-bit Audio
`MagicRAM,
`Adapter.”, No Date.
`
`Fujitsu Personal Systems, Inc. brochure for “Stylistic 500.”,
`Nodate.
`
`Industrial Monitoring Instrumentation Catalog QSG—200.,
`No Date.
`
`Entek Scientific Corporation User’s Guide entitled “Emoni-
`tor for Windows.”, No Date.
`
`2
`
`

`

`U.S. Patent
`
`Sep. 15, 1998
`
`Sheet 1 of 7
`
`5,808,903
`
`
`
`120
`
`
`210
`
`230
`
`240
`
`220
`
`FIG. 2,
`
`160
`115
`
`
`ACCELEROMETER
`
`
`
`
`
` !
`
`ANG DATABASE
`
`3
`
`

`

`U.S. Patent
`
`Sep. 15, 1998
`
`Sheet 2 of 7
`
`5,808,903
`
`
`
`150
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`
`520
`
`516
`
`SIGNAL PROCESSING
`925
`
`4
`
`

`

`U.S. Patent
`
`Sep. 15, 1998
`
`Sheet 3 of 7
`
`5,808,903
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`600
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`U.S. Patent
`
`Sep. 15, 1998
`
`Sheet 5 of 7
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`5,808,903
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`U.S. Patent
`
`Sep. 15, 1998
`
`Sheet 6 of 7
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`5,808,903
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`U.S. Patent
`
`Sep. 15, 1998
`
`Sheet 7 of 7
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`5,808,903
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`9
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`

`

`5,808,903
`
`1
`
`PORTABLE, SELF-CONTAINED DATA
`COLLECTION SYSTEMS AND METHODS
`
`FIELD OF THE INVENTION
`
`This invention relates to predictive maintenance systems
`and methods, and more particularly to computer-based data
`collection systems and methods for measuring and collect-
`ing vibration data from machines.
`BACKGROUND OF THE INVENTION
`
`Data collection systems and methodsare now widely used
`for measuring and collecting vibration data from machines,
`for predictive maintenance purposes. Data collection sys-
`tems typically include two major components: a portable
`data collector and a host computer. The portable data col-
`lector is typically a dedicated instrument to which acceler-
`ometers can be coupled, and which stores accelerometer-
`based vibration data for a machine. An example of a
`state-of-the-art data collector is the EMONITOR® data-
`line™ data collector marketed by Entek Scientific
`Corporation, assignee of the present application. The
`EMONITOR® dataline™ data collector is described in a
`manual entitled “EMONITOR® for Windows EMONITOR®
`dataline™ (U.S.) Data Collector User’s Guide, First Edi-
`tion 1995”, Manual No. EEW2501A,published by Entek
`Scientific Corporation, the disclosure of which is incorpo-
`rated herein by reference.
`The host computer is typically a standard PC-based
`computer which runs predictive maintenance data manage-
`ment and analysis software thereon. The host software
`allowsa userto set up a database to model the machinery for
`which vibration data is to be obtained. The software allows
`lists of machines to be set up for data collection. Each list
`includesa set of measurement parameters that control where
`and how to take and store a measurement. The host software
`allows one or morelists to be loaded into the data collector
`for collection. The user then takes the data collector to a
`
`machine to be measured, accesses the measurement param-
`eters for that machine, and collects and stores vibration and
`other information. After collection,
`the data is unloaded
`from the data collector to the host. The host software then
`allows the data to be analyzed. Reports can be generated,
`including reports of measurements that exceed alarms.
`Graphical displays of the data can be produced, including
`trend, spectrum, frequency trend, time waveform and spec-
`trum mapplots.
`An example of data management and analysis host soft-
`ware is EMONITOR® for Windows, which is marketed by
`Entek Scientific Corporation,
`the assignee of the present
`invention. The EMONITOR® for Windows software is
`
`described in a manualentitled “EMONITOR® for Windows
`User’s Guide, Second Edition 1994”, Manual No.
`EEW0002B, published by Entek Scientific Corporation, the
`disclosure of which is incorporated herein by reference.
`In state-of-the-art manufacturing environments, the capi-
`tal investment in machinery can be staggering. Accordingly,
`there is a great need for predictive maintenance to prevent
`machine breakdowns and increase reliability. Moreover,
`with “just in time” manufacturing requirements, predictive
`maintenance becomes even more critical
`to eliminate
`
`machine down time. Accordingly, there is a great need for
`data collection systems and methods.
`Unfortunately, the high cost of data collection systemsis
`often a barrier to their widespread use. The high cost is in
`part related to the use of special purpose hardware and
`software in the data collector. In addition to high cost, the
`
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`use of special purpose hardware and software limits the
`flexibility of the data collector and makes it difficult
`to
`update and improve the data collector. Although portable
`computers, laptop computers, penbased computers, palmtop
`computers and personal Digital Assistants (PDA) have
`become widely available, they have not yet made a signifi-
`cant impact on data collectors. See for example, the publi-
`cation in Automatic ID News, April 1995, entitled “Be
`Ready for Technology Leap at the End of the Century: Three
`Non-ADC Developments to Springboard Automatic Data
`Capture Growth”. See also the publication in Maintenance,
`January/February 1995, by Billsonet al. entitled “Portable
`Pen Computers—An Essential Tool for the Mobile Mainte-
`nance Engineer”.
`SUMMARYOF THE INVENTION
`
`The present invention is a portable, self-contained data
`collection system for measuring and collecting vibration
`data from machines. The system includes an accelerometer
`including a motion sensitive transducer and an accelerom-
`eter output. The accelerometer is coupled to a machine to
`produce an analog signal at the accelerometer output. The
`system also includes a data acquisition card having an
`analog input and a digital output. The accelerometer output
`is electrically coupled to the analog input. As used herein,
`electrical coupling includes wireless, optical or conventional
`wire coupling. The data acquisition card samples and digi-
`tizes the analog signal to produce a time domain digital
`signal, i.e. a sampled and digitized series of voltage versus
`time points, at the digital output. The system also includes
`a battery-powered portable computer such as a pen-based
`computer, which includes an expansion slot. The data acqui-
`sition card digital output is electrically and mechanically
`connected to the expansionslot.
`The battery-powered portable computer also includes a
`database having machineidentifications and associated mea-
`surement parameters. User input meanssuch as a pen allows
`user selection of a machine identification for measurement.
`The portable computer also includes signal processing
`meansfor processing the time domain digital signal accord-
`ing to the measurement parameters associated with the
`selected machine identification. preferably, the signal pro-
`cessing means processes the time domain digital signal to
`produce a frequency domain digital signal by performing a
`Fast Fourier Transform (FFT), waveletor other digital signal
`processing operations. Finally, the battery-powered portable
`computer also preferably includes signal analyzing means
`for analyzing the frequency domain digital signal to produce
`predictive maintenance information such as spectral distri-
`bution. The time domain digital signal can also be analyzed
`to produce crest factor and other predictive maintenance
`information.
`
`A data collection system according to the present inven-
`tion uses a standard portable computer such as a pen-based
`computer and a standard data acquisition card such as a
`PCMCIA sound card,
`to provide portable self-contained
`hardware for data collection and analysis. The machine
`database, signal processing means and signal analyzing
`means are preferably implemented using software modules
`which execute on the portable computer. The machine
`database and the signal analyzing software may be provided
`using EMONITOR® for Windowsor other predictive main-
`tenance software on the portable computer. Signal process-
`ing software may be provided by conventional digital signal
`processing software which provides digital filtering, inte-
`gration from acceleration to velocity or displacementunits,
`Fast Fourier Transform or other mathematical functions, and
`
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`

`5,808,903
`
`3
`averaging. Accordingly, a low cost self-contained data col-
`lection system is provided.
`It will be understood that since the portable data collec-
`tion system includes a database, signal processing software
`and signal analyzing software therein, a host computer
`connection is not required for operation. Rather, all predic-
`tive maintenance operations may be performed using only
`the portable self-contained data collection system. However,
`it will also be understood by those having skill in theart that
`the portable self-contained data collection system can be
`used as part of a networked data collection system wherein
`the portable computer includes transmitting meansfortrans-
`mitting at
`least one of the machine identifications,
`the
`measurement parameters, the time domain digital signal, the
`frequency domain digital signal or the predictive mainte-
`nance information to a second computer. The second com-
`puter may store this data for distribution to other users and
`the second computer or other users may also perform one or
`more of the processing functions of the portable data col-
`lector. The transmitting meansis preferably wireless, such as
`a radio frequency (RF) transmitter. However, transmission
`may also be accomplished by uploading information to
`another computer using conventional wire communications.
`According to another aspect of the present invention, the
`portable self-contained data collection system also includes
`a powersupply for supplying powerto the accelerometer. In
`particular, conventional portable computers do not provide
`sufficient power for an accelerometer, which typically
`requires 24 V at 2 mA. According to the invention, an
`accelerometer power supply electrically and mechanically
`couples the accelerometer output to the data acquisition card
`analog input. The accelerometer power supply is preferably
`responsive to the data acquisition card for supplying power
`to the accelerometer when the data acquisition card is
`activated, and for deactivating when the data acquisition
`card is deactivated.
`
`In particular, the accelerometer power supply includes a
`power supply housing and an accelerometer battery power
`supply in the power supply housing which provides suffi-
`cient powerfor an accelerometer. Output meansincluding an
`output connectorelectrically and mechanically connects the
`accelerometer battery power supply to an accelerometer and
`receives accelerometer signals from the accelerometer. Input
`means including an input connector electrically and
`mechanically connects the accelerometer battery power sup-
`ply to an external device, preferably the analog input of a
`data acquisition card. The input means receives a control
`signal from the external device, and also passes the accel-
`erometer signals to the external device. The accelerometer
`battery power supply is responsive to the control signal, to
`activate the accelerometer battery power supply to supply
`battery power for an accelerometer to the output connector.
`In the absence of the control signal,
`the accelerometer
`battery power supply is deactivated. Preferably, the accel-
`erometer battery power supply will pass signals from the
`output means to the external device in the absence of the
`control signal, so that non-powered transducers can be used.
`When the accelerometer power supply is included, the
`portable self-contained data collection system includes three
`hardware components: a portable computer, a data acquisi-
`tion card and an accelerometer power supply. The portable
`computer includes a portable computer housing, a portable
`computer battery power supply within the portable computer
`housing to supply power to the portable computer, and an
`expansion slot in the portable computer housing. The data
`acquisition card is mechanically and electrically coupled to
`the expansion slot. The accelerometer power supply
`
`4
`includes a power supply housing, and an accelerometer
`battery power supply within the power supply housing
`which provides sufficient power for an accelerometer. The
`accelerometer powersupply is electrically and mechanically
`coupled to the data acquisition card and the accelerometeris
`electrically and mechanically coupled to the accelerometer
`powersupply. The portable computer, data acquisition card
`and accelerometer power supply may be packaged in a
`ruggedized carrying case. The portable computer executes
`software including a database including machine identifica-
`tions and measurement parameters, signal processing soft-
`ware for processing accelerometer signals and signal ana-
`lyzing software for analyzing the processed signal
`to
`produce predictive maintenance information.
`Data collection methods according to the present inven-
`tion are used for measuring and collecting vibration data
`from machines, wherein the following steps are all per-
`formed in a portable battery-powered computer: A machine
`identification for measurementis selected. A time domain
`
`accelerometer signal is processed according to measurement
`parameters associated with the selected machine identifica-
`tion to producea digital signal. The digital signal is analyzed
`to produce predictive maintenance information. If necessary,
`the processing step is preceded by the step of sampling and
`digitizing an analog accelerometer signal to produce the
`time domain accelerometer signal. The machine
`identifications, measurements, time domain signal, digital
`signal and/or predictive maintenance information can be
`displayed on the portable battery-powered computer. Por-
`table self-contained data collection systems and methodsare
`thereby provided. In addition, this information can betrans-
`ferred to another computer.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 illustrates a data collection system for collecting
`vibration data from machines according to the present
`invention.
`
`FIG. 2 is a block diagram illustrating a data acquisition
`card interfaced to an operating system, database, signal
`processing means and signal analyzing means implemented
`in a battery operated portable computer according to the
`present invention.
`FIG. 3 is a block diagram illustrating signal processing
`means,
`including filtering,
`integration,
`fast Fourier
`transform, and averaging, for processing a time domain
`digital signal according to the present invention.
`FIG. 4 is a block diagram illustrating a power supply for
`an accelerometer according to the present invention.
`FIGS. 5a—5b illustrate data collection operations accord-
`ing to the present invention.
`FIGS. 6a—6c are computer screen images illustrating a
`machine identification selection according to the present
`invention.
`
`FIG. 7 is a computer screen image illustrating signal
`analyzing according to the present invention.
`FIG. 8 is a diagram illustrating a data collection system
`implemented in a battery operated portable computer linked
`to other computers in a computer network according to the
`present invention.
`DETAILED DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`The present invention now will be described more fully
`hereinafter with reference to the accompanying drawings,in
`which preferred embodiments of the invention are shown.
`
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`5,808,903
`
`5
`This invention may, however, be embodied in manydifferent
`forms and should not be construed as limited to the embodi-
`ments set forth herein; rather, these embodiments are pro-
`vided so that this disclosure will be thorough and complete,
`and will fully convey the scope of the invention to those
`skilled in the art. Like numbers refer to like elements
`throughout.
`Referring now to FIG. 1, data collection system 100 is
`illustrated, housed in a case 101. As shown,data collection
`system 100 includes a battery-powered portable computer
`110 mating to data acquisition card 120, display means 130,
`user input means 140, power supply 150, and accelerometer
`160.
`
`The construction of battery powered portable computer
`110 is well-known to those skilled in the art. Battery
`operated portable computers typically include a
`microprocessor, associated random access memory (RAM),
`nonvolatile data storage such as a hard disk drive, a battery
`power source and expansionslots designed to accommodate
`circuit boards electrically coupling the computer compo-
`nents to external devices such as keyboards, pens, mouses,
`transducers and displays. These expansion slots typically
`accommodate standard form factor circuit cards, such as the
`industry-standard PCMCIAform factor cards used in note-
`book and laptop computers. For field uses, such as moni-
`toring of machinery for predictive maintenance purposes,
`battery operated portable computer 110 may be mounted in
`a lightweight, rugged hand-held case 101, and user input
`means 140 may include a magnetic pen designed to operate
`with a magnetically sensitive screen matrix. An example of
`a typical battery operated portable computer designed espe-
`cially for field use is the Fujitsu Stylistic 500, as described
`in Fujitsu brochure 58-0349-00B, the disclosure of whichis
`incorporated herein by reference. This computeris referred
`to for purposes of explanation only, and it will be understood
`by those skilled in the art that the present invention may be
`used with other portable computers.
`Data acquisition card 120 is an analog to digital (A/D)
`converter card that mechanically and electrically couples
`data acquisition card 120 to an expansion slot in battery
`powered portable computer 110, electrically connecting
`digital output 122 to battery operated portable computer 110.
`Data acquisition card 120is electrically coupled to acceler-
`ometer 160 at analog input 121. Typically, data acquisition
`card 120 is a low-cost standard form factor sound card
`
`designed to receive audio frequency analog signals at analog
`input 121. An example of such a sound card is the Magic
`Ram PCMCIA 16-bit audio adapter, which is described in a
`manufacturer’s data sheet entitled “PCMCIA 16-bit Audio
`
`Adapter,” the disclosure of which is incorporated herein by
`reference. This device is a standard PCMCIA form factor
`
`card that mates with a PCMCIAexpansionslot. It will be
`understood by those skilled in the art that a data acquisition
`card according to the present invention includes any A/D
`converter card capable of receiving analog inputs and trans-
`mitting corresponding digital signals to a battery operated
`portable computer through a digital communications port,
`such as an expansionslot.It will also be understood by those
`skilled in the art that the present invention may be used with
`a battery operated portable computer 110 which includes an
`analog input and associated internal A/D.
`Accelerometer 160 produces an analog signal correspond-
`ing to the accelerations experienced by a motion sensitive
`transducer included therein, and is electrically coupled to
`data acquisition card 120 by analog input 121. The motion-
`sensitive transduceris typically piezoelectric and produces a
`voltage proportional to the acceleration of the transducer.
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`The accelerometer includes means for coupling the motion
`sensitive transducer to a machine from which the user
`desires vibration data, such as a probe extension, screw or
`magnet attached to the accelerometer structure. Examples of
`piezoelectric accelerometers may be found in Catalog QSG-
`200, published by Industrial Monitoring Instrumentation
`Division of PCB piezotronics, Inc., the disclosure of which
`is incorporated herein by reference. It will be understood by
`those skilled in the art that the present invention may be used
`with other measurement devices producing analog output
`signals corresponding to accelerations, such as piezotrans-
`istor or variable resistance accelerometers.
`
`power supply 150 supplies electrical power to acceler-
`ometer 160, receives output signals from accelerometer 160,
`receives control signals from data acquisition card 120, and
`conveys output signals from accelerometer 160 to data
`acquisition card 120. Power supply 150 is mechanically and
`electrically coupled to both accelerometer 160 and data
`acquisition card 120.
`Referring now to FIG. 2, a block diagram illustrates
`accelerometer 160, data acquisition card 120 and user input
`means 140 interfaced to an operating system 200, data
`collection interface 210, database 220, signal processing
`means 230 and signal analyzing means 240. Operating
`system 210 is typically executive software that controls data
`collection interface 210, database 220, signal processing
`means 230, signal analyzing means 240, and data acquisition
`card 120, responsive to commands received through user
`input means 140. Such commands maybeto acquireor store
`data, or to perform filtering,
`time domain analysis, or
`frequency domain analysis. An example of operating system
`200 is Entek Scientific Corporation’s EMONITOR® for
`Windows data management software, as described in
`“EMONITOR®for Windows User’s Guide, Second Edition
`1994,” Manual No. EEW0002B, the disclosure of which is
`incorporated herein by reference. This software is a
`Windows-based program that enables a user to perform
`database manipulation, data analysis or other operations via
`manipulation of screen icons. It will be understood by those
`skilled in the art that the present invention may be used,for
`example, with other operating systems running in a
`Windows, DOS, or UNIX environment.
`Database 220 comprises a plurality of machine identifi-
`cations and associated measurement parameters. Database
`220 may havea hierarchical, relational or other structure and
`is typically organized according to logical relationships
`between particular machines. An example of a hierarchical
`database structure is incorporated in Entek Scientific Cor-
`poration’s EMONITOR® for Windows, as described in
`Chapters 4 and 5 of “EMONITOR® for Windows User’s
`Guide, Second Edition 1994,” Manual No. EEWO002B.
`This database is a SQL database that organizes machine
`identifications, and associates parameters such as machine
`location, signal processing parameters and previously mea-
`sured data values with these machine identifications. This
`database is referred to for purposes of explanation, and it
`will be understood by those skilled in the art that the present
`invention may be used with other hierarchical or non-
`hierarchical database structures, and may include various
`combinations of machine parameters.
`Data collection interface 210 is preferably a software
`module that controls the operation of data acquisition card
`120 and signal processing means 230 through operating
`system 200, although hardware or software/hardware com-
`binations may be employed. Upon commands from data
`collection interface 210, data acquisition card 120 samples
`and digitizes an analog signal 115 received from a acceler-
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`ometer 160 and provides a corresponding time domain
`digital signal 125, which is conveyed to signal processing
`means 230. In the embodiment of the present invention
`shown in FIG. 2, data collection interface 210 is a software
`module operating in conjunction with,
`for example, an
`operating system such as EMONITOR® for Windowsrun-
`ning in a Windows environment, and is conveniently
`accessed and controlled by user selection of appropriate
`icons in a display window.
`Although the combination of elements described in FIG.
`2 envisions data collection, database management and data
`analysis integrated in a multitasking environment such as
`Windows, it will be understood by those skilled in the art
`that the present invention may be practiced using other
`means of interfacing data acquisition card 120, signal pro-
`cessing means 230, signal analyzing means 240 and data-
`base 220. For example, data collection interface 210 may be
`a standalone software program capable of transferring data
`from data acquisition card 120 to database 220 for subse-
`quent data management, signal processing and signal analy-
`sis. In another arrangement, data acquisition card 120 may
`include all or a portion of signal processing means 230,
`allowing sampling, digitizing and processing of analog
`signal 115 to be performed on data acquisition card 120. An
`example of such an integrated PCMCIAcardis the Bullet,,,,
`card marketed by Communication Automation and Control,
`Inc. The Bullet,,,, card is described in a data sheet entitled
`“PCMCIA TI TMS320C32, ” published by Communication
`Automation and Control, Inc., the disclosure of which is
`incorporated herein by reference.
`Signal processing means 230 performs digital signal
`processing of time domain digital signal 125 received from
`data acquisition card 120. Typically, signal processing
`means 230 is implemented in conventional modular soft-
`ware blocks, which may be selected and combined to
`perform various processing functions, as further illustrated
`in FIG. 3. This software may implement functions such as
`filtering, fast Fourier transform, integration or averaging,
`which may be selected and arranged as desired.
`Signal analyzing means 240 typically is software that
`examines processed digital signals received from signal
`processing means 230 and produces predictive maintenance
`information. Upon commands received through operating
`system 200, signal analyzing means 240 conducts analyses
`such as trend analysis, alarm detection, spectral analysis,
`data plotting or report generation. An example of signal
`analyzing means 240is the analysis software incorporated in
`Entek Scientific Corporation’s EMONITOR® for Windows,
`as described in Chapters 7, 9, 10 and 11 of “EMONITOR®
`for Windows User’s Guide, Second Edition 1994,” Manual
`No. EEW0002B.
`
`Referring now to FIG. 3, a software block diagram
`illustrates signal processing software for implementing sig-
`nal processing means 230 which includes modular process-
`ing elements 310a—310d which maybe selected and com-
`bined as required. It will be understood by those skilled in
`the art that other arrangements of signal processing elements
`may be used with the present invention. In addition, it will
`be understood by those skilled in the art that other non-
`modular signal processing software techniques may be used
`with the present invention.
`Referring now to FIG. 4, an electrical block diagram
`illustrates power supply 150 for accelerometer 160. Power
`supply housing 410 encloses accelerometer battery power
`supply 420. Accelerometer battery power supply 420 pro-
`vides sufficient power to excite an external accelerometer.
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`Output means 430 electrically and mechanically couples
`accelerometer battery power supply 420 to an external
`accelerometer. Typically, output means 430 will include an
`MS-3106 connector commonly used in accelerometer
`applications, but it will be understood by those skilled in the
`art
`that other structures may be used with the present