DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0024] 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. This invention may, however, 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 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.

[0025] 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 .

[0026] 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 expansion slots designed to accommodate circuit boards electrically coupling the computer components 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 PCMCIA form factor cards used in notebook and laptop computers. For field uses, such as monitoring 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 especially for field use is the Fujitsu Stylistic 500, as described in Fujitsu brochure 58-0349-00B, the disclosure of which is incorporated herein by reference. This computer is 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.

[0027] 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 120 is electrically coupled to accelerometer 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 PCMCIA expansion slot. 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 transmitting corresponding digital signals to a battery operated portable computer through a digital communications port, such as an expansion slot. 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.

[0028] Accelerometer 160 produces an analog signal corresponding 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 transducer is typically piezoelectric and produces a voltage proportional to the acceleration of the transducer. 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 piezotransistor or variable resistance accelerometers.

[0029] Power supply 150 supplies electrical power to accelerometer 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 .

[0030] 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 may be to acquire or 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.

[0031] Database 220 comprises a plurality of machine identifications and associated measurement parameters. Database 220 may have a 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 Corporation's EMONITOR® for Windows, as described in Chapters 4 and 5 of “EMONITOR® for Windows User's Guide, Second Edition 1994,” Manual No. EEW0002D. This database is a SQL database that organizes machine identifications, and associates parameters such as machine location, signal processing parameters and previously measured 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.

[0032] 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 combinations may be employed. Upon commands from data collection interface 210 , data acquisition card 120 samples and digitizes an analog signal 115 received from a accelerometer 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 Windows running in a Windows environment, and is conveniently accessed and controlled by user selection of appropriate icons in a display window.

[0033] 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 processing means 230 , signal analyzing means 240 and database 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 subsequent data management, signal processing and signal analysis. 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 PCMCIA card is the Bullet _dsp card marketed by Communication Automation and Control, Inc. The Bullet _dsp card is described in a data sheet entitled “ PCMCIA TI TMS 320 C 32,” published by Communication Automation and Control, Inc., the disclosure of which is incorporated herein by reference.

[0034] 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 software 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.

[0035] 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 240 is 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.

[0036] Referring now to FIG. 3, a software block diagram illustrates signal processing software for implementing signal processing means 230 which includes modular processing elements 310 a - 310 d which may be selected and combined 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.

[0037] 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 provides sufficient power to excite an external accelerometer. 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 invention, including coaxial and other types of standard connectors.

[0038] Input means 440 electrically and mechanically couples accelerometer battery power supply 420 to an external device, such as an A/D converter, and receives control signal 450 from the external device. Accelerometer battery power supply 420 may be responsive to control signal 450 , deactivating power output to the external accelerometer in the absence of control signal 450 , thus offering the capability to minimize power consumption during non-measurement periods and extending battery life or time between recharges.

[0039] FIG. 4 shows accelerometer battery power supply 420 further including battery 422 , charging means 424 , and regulating means 426 . Charging means 424 provides the capability to charge battery 422 . Regulating means 426 takes the power output from battery 422 and provides the voltage and current conditioning required to excite the external accelerometer. It will be understood by those skilled in the art that not all of these elements are required for all embodiments of the present invention. Different power supply configurations may, for example, utilize disposable or removable batteries and eliminate the need for internal charging means 424 .

[0040] FIG. 5 a illustrates operations for measuring and collecting vibration data from machines, implemented in a battery-operated powered computer. First, in Block 510 a user selects a machine identification for measurement. In Block 520 a time domain accelerometer signal 515 is processed to produce a digital signal 525 . In Block 530 the digital signal is analyzed to produce predictive maintenance information, such as detection of alarm conditions due to vibration magnitudes exceeding predetermined limits or reports concerning machine vibration parameters. Referring to FIG. 5 b , in an alternate embodiment, the operations of Block 520 may be preceded by a step of sampling and digitizing an analog time domain accelerometer signal to produce a time domain digital accelerometer signal 516 , as shown in Block 511 . In addition, predictive maintenance information 526 may then be displayed, as shown in Block 540 .

[0041] FIGS. 6 a - 6 b illustrate the selection step of Block 510 of FIGS. 5 a - 5 b in greater detail. In FIG. 6 a the user enters a data collection window 600 in which he may select a machine identification for measurement, as shown at 601 . The display informs the user of the identification selected, which typically is a location on a particular machine, as shown at 602 . The user typically commands data acquisition by selection of an icon, as shown at 603 .

[0042] The parameters associated with a particular machine identification typically have been previously entered into a database. This may be done manually, as shown in FIG. 6 b . Within a data entry window 610 , the user selects a desired machine identification, as illustrated at 611 , and enters the associated parameters, as shown at 612 . Alternatively, parameters may be entered with the aid of predetermined machine templates, as shown in FIG. 6 c . These parameters may include signal processing parameters for use in the processing step of Block 520 of FIG. 5 , but it will be understood by those skilled in art that other arrangements may be used with the present invention, such as allowing the user to select particular signal processing parameters while in data collection window 600 .

[0043] FIG. 7 illustrates the signal analyzing operation of Block 530 of FIG. 5 , specifically the displayed results of a spectrum analysis. It will be understood by those skilled in the art that other analyses may be performed on digital signals, such as magnitude or crest factor calculations or detection of alarm conditions.

[0044] FIG. 8 illustrates the data collection system of the present invention further including transmission of machine identifications, measurement parameters, time domain accelerometer signals, frequency domain digital signals and predictive maintenance information to other computers 820 a - 820 n linked to the battery operated portable computer 110 by means of a network 810 . It will be understood by those skilled in the art that network 810 may be hardwired or may employ radio frequency (RF) or other communications links. Under this aspect of the invention, machine-related data may be uploaded from the battery powered portable computer 110 to computers 820 a - 820 n for subsequent data management, processing, analysis or display.

[0045] In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.