Abstract:
A portable route-based machine data collector stores audio files to supplement associated machine performance data, such as vibration data. The audio files, which may include voice comments, audio segments of raw vibration data, or frequency-shifted components of the vibration data, are stored in the data collector as standard-format digital audio files and are later downloaded to a computer for further analysis. Test personnel can then replay the audio files for data analysis personnel to get second opinions regarding whether machine faults may be indicated by the recorded sounds. Also, audio files associated with normal and abnormal machine operation may be saved on the portable data collector and used as baselines or for training purposes. Verbal operating instructions may also be stored as audio files on the portable data collector for replay by test operators in the field. In a case where the portable data collector is an ultrasonic monitoring unit, frequency-shifted (audible) ultrasonic data may be stored in an audio file in association with non-shifted ultrasonic data.

Description:
FIELD 
   This invention relates to the field of industrial machine monitoring and fault analysis. More particularly, this invention relates to a system for acquiring data indicative of operational characteristics of industrial machines. 
   BACKGROUND 
   Portable route-based data collectors and analyzers are used to acquire data for indicating the operational status of industrial machines. For example, some data collectors are used to measure vibration of various machines along a measurement route within an industrial facility. Vibration characteristics of the machines are typically stored as digital vibration data that may be analyzed to detect faults in the operation of the machines. The CSI Model 2117A1, manufactured by Emerson Process Management, is an example of one such route-based vibration data collector unit. 
   Other examples of route-based data collector units include portable ultrasonic units for measuring ultrasonic characteristics of machines, and portable infrared camera units for measuring machine temperature characteristics. 
   To aid in more fully understanding machine performance data and the circumstances surrounding the acquisition of machine performance data, it would be desirable to record short audio files along with the machine data. For example, it would be helpful in some situations for a data analyst to hear audible sounds generated by a machine as the machine creates a particular vibration characteristic. It would also be desirable for test personnel to be able to record verbal notes regarding a measurement at a particular route point and to store the verbal notes in association with test data collected at the route point. No prior route-based data collector unit has provided this capability. 
   What is needed, therefore, is the ability to store audio files on a route-based data collector to supplement machine performance data also recorded on the data collector. Also needed is a route-based data collector on which verbal instructions or reminders can be recorded for playback to operators when a measurement at a route point is initiated, on which route notes can be entered verbally rather than textually as measurements are made along a route, and on which an audio library of faults can be stored for playback and comparison when listening for faults in the field. 
   SUMMARY 
   The above and other needs are met by a portable route-based machine data collector that stores audio files (also referred to herein as “sound bites” or “audio annotations”) to supplement associated machine performance data. The audio files, which may include audio segments of raw vibration data, frequency-shifted vibration data or voice annotations, may be stored in the data collector as standard-format digital audio data files and later downloaded into route-based data files for further analysis. Using the invention, test personnel can replay the audio files for data analysts to get second opinions regarding whether machine faults may be indicated by the recorded sounds. Also, audio files associated with normal and abnormal machine operation may be saved and used as baselines or for training purposes. In some embodiments of the invention, frequency-shifted or time-expanded vibration data or ultrasonic data may be stored as audio data in an audio file in association with the original vibration or ultrasonic data. 
   According to some preferred embodiments, the invention may be used to record verbal instructions or reminders that are played back to test operators when a route point is activated on a route-based portable data collection unit. In some embodiments, the invention provides for entering route notes verbally rather than using text input. In some embodiments, the invention provides for storing an audio library of faults on a data collector for playback and comparison when listening for faults in the field. The data collector unit of some preferred embodiments communicates wirelessly with a headset/microphone for recording audio notes and listening to baseline audio data in the field. 
   In some preferred embodiments, the invention provides a portable apparatus for acquiring information indicative of the operational status of machines distributed at various locations along a measurement route. The apparatus comprises one or more sensors for measuring characteristics of a machine at a location on the measurement route. Based on the sensed characteristics, the one or more sensors generate one or more analog sensor signals that include one or more frequency components that may be beyond a human-audible frequency range. The apparatus includes a sound sensor for generating an analog audio signal associated with the characteristics of the machine measured by the one or more sensors. Preferably, the analog audio signal is generated at one or more frequencies that are within the human-audible frequency range. The apparatus includes one or more analog-to-digital conversion circuits for converting the one or more analog sensor signals and the analog audio signal to digital sensor data and digital audio data, respectively. A digital storage device in the apparatus stores the digital sensor data and the associated digital audio data. 
   In one preferred embodiment, the invention provides a portable apparatus for acquiring information indicative of the operational status of a machine in an industrial environment. The portable apparatus includes a measurement sensor for measuring a characteristic of the machine and generating an analog sensor signal based thereon, where the analog sensor signal includes inaudible frequency components that are beyond a human-audible frequency range. The apparatus includes an analog-to-digital conversion circuit for converting the analog sensor signal to digital sensor data. A processor receives and processes the digital sensor data to shift the inaudible frequency components into the human-audible frequency range. This frequency-shifting process generates digital audio data that includes at least the frequency-shifted components. The apparatus also includes a digital storage device for storing the digital audio data in association with the digital sensor data. 
   In another aspect, the invention provides a method for acquiring information using a portable route-based measurement apparatus, where the acquired information is indicative of the operational status of machines distributed at various locations along a measurement route. The method includes steps of (a) sensing a characteristic of a machine at a location on the measurement route, (b) generating a sensor signal based on the sensed characteristic where the sensor signal includes one or more frequencies that may be beyond a human-audible frequency range, (c) generating an audio signal associated with the sensed characteristic of the machine where the audio signal includes one or more frequencies that are within the human-audible frequency range, (d) storing the sensor signal on the portable route-based measurement apparatus as digital sensor data that is associated with the location along the measurement route, and (e) storing the audio signal on the portable route-based measurement apparatus as digital audio data that is associated with the location along the measurement route. 
   In yet another aspect, the invention provides a method for storing information indicative of the operational status of one or more machines using a portable machine data measurement apparatus. The method includes steps of (a) storing digital audio data files containing audio data that is representative of audio sounds produced by machines experiencing various fault conditions, (b) displaying a list of fault conditions on the portable apparatus, (c) receiving first selection input from an input device associated with the portable apparatus, where the first selection input indicates a selection of a fault condition from the list, (d) accessing a digital audio files associated with the selected fault condition, (e) generating sound based on the accessed digital audio file, where the sound is representative of a sound produced by a machine experiencing a particular fault condition, (f) receiving second selection input from the input device, where the second selection input indicates a selection of a test setup file for setting up the portable apparatus to collect data for diagnosing the particular fault condition, (g) sensing characteristics of the machine using the portable apparatus set up according to the selected test setup file, (h) generating sensor signals based on the sensed characteristics, and (i) storing the sensor signals on the portable apparatus as digital sensor data. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further advantages of the invention are apparent by reference to the detailed description in conjunction with the figures, wherein elements are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein: 
       FIG. 1  depicts a functional block diagram of a portable machine data collection unit according to a preferred embodiment of the invention; and 
       FIG. 2  depicts a method for recording sensor data and associated audio data on a portable machine data collection unit according to a preferred embodiment of the invention. 
   

   DETAILED DESCRIPTION 
     FIG. 1  generally depicts a portable machine data collection apparatus  10  according to a preferred embodiment of the invention. In various embodiments described herein, the apparatus  10  is used in measuring machine performance characteristics of one or more machines in an industrial setting. Examples of machine performance characteristics include vibration, ultrasonic emissions, revolutions-per-minute (RPM) and infrared emissions. In a preferred embodiment, the apparatus  10  is used in making measurements on multiple machines distributed along a “measurement route” within an industrial facility. In this embodiment, the apparatus  10  may store measurement setup information, measurement instructions and measured data for each measurement point along the route. 
   The following description of the operation of the apparatus  10  also makes reference to  FIG. 2  which depicts steps in a method for collecting and storing sensor data and associated audio data. 
   As shown in  FIG. 1 , the apparatus  10  includes a measurement sensor  12   a  for sensing one or more characteristics of an industrial machine while the machine is operating (step  100  in  FIG. 2 ). In an exemplary embodiment, the sensor  12   a  is an accelerometer or velocimeter for measuring vibration characteristics of the industrial machine. In another embodiment, the sensor  12   a  is an ultrasonic sensor for detecting ultrasonic emissions from machines. In each embodiment, the sensor  12   a  generates a sensor signal that is indicative of one or more operational characteristics of a machine-under-test (step  102  in  FIG. 2 ), which characteristics may include vibration, ultrasonic emissions or other characteristics. For example, in an embodiment wherein the sensor  12   a  is an accelerometer, the sensor signal is a vibration signal. In an embodiment wherein the sensor  12   a  is an ultrasonic sensor, the sensor signal is an ultrasonic emission signal. 
   The analog sensor signal generated by the sensor  12   a  is provided to signal conditioning circuitry  15   a . The signal conditioning circuitry  15   a  preferably includes signal filter, offset and gain stages as are well known to those skilled in the art. The conditioned analog sensor signal at the output of the signal conditioning circuitry  15   a  is provided to an analog-to-digital conversion circuit (ADC)  16   a  which converts the analog sensor signal to digital sensor data. Those skilled in the art will appreciate that the sensor  12   a , signal conditioning circuitry  15   a  and ADC  16   a  may be contained within a common sensor housing. Alternatively, the ADC  16   a  and conditioning circuitry  15   a  may be contained within a housing that is separate from that of the sensor  12   a.    
   The apparatus  10  also preferably includes a measurement sensor  12   b  for sensing characteristics of an industrial machine that are generally not vibration-related, such as infrared emissions (temperature) or RPM. In an exemplary embodiment, the sensor  12   b  is an infrared sensor for capturing infrared images of the industrial machine. In another embodiment, the sensor  12   b  is a tachometer for measuring RPM. In each embodiment, the sensor  12   b  generates a sensor signal that is indicative of the sensed operational characteristic of a machine-under-test. For example, in an embodiment wherein the sensor  12   b  is an infrared sensor, the sensor signal is a thermal signature signal. In an embodiment wherein the sensor  12   b  is a tachometer, the sensor signal is an RPM signal. 
   The analog sensor signal generated by the sensor  12   b  is provided to signal conditioning circuitry  15   b . The signal conditioning circuitry  15   b  preferably includes signal filter, offset and gain stages as are well known to those skilled in the art. The conditioned analog sensor signal at the output of the signal conditioning circuitry  15   b  is provided to an analog-to-digital conversion circuit (ADC)  16   b  which converts the analog sensor signal to digital sensor data. Those skilled in the art will appreciate that the sensor  12   b , signal conditioning circuitry  15   b  and ADC  16   b  may be contained within a common sensor housing. Alternatively, the ADC  16   b  and conditioning circuitry  15   b  may be contained within a housing that is separate from that of the sensor  12   b.    
   The digital sensor data at the output of the ADCs  16   a  and  16   b  is provided to a processor  18 . In preferred embodiments, the processor  18  includes one or more sensor data processing modules  40  for performing analysis routines on the sensor data. For example, in embodiments of the invention wherein the sensor data is time-based vibration data, the data processing module  40  may perform a Fast Fourier Transform (FFT) of the time-based vibration data to generate a frequency spectrum of the vibration data. Other functions provided by the processor  18  include calibration and measurement setup functions, display control functions, and data transfer and storage functions. 
   As shown in  FIG. 1 , the processor  18  includes a frequency-shift module  36  for shifting the frequency of components of the sensor signal detected by the measurement sensor  12   a . For example, if the sensor  12   a  is an accelerometer, it will generally produce sensor signals having some frequency components that are above human hearing range. The frequency-shift module  36  digitally alters the sensor data according to well known processing techniques to shift high-frequency components (such as components above 20 KHz) downward by about 10 KHz into the audible range (step  104  of  FIG. 2 ). These frequency-shifted sensor signals may then be stored as digital audio data in association with the non-shifted sensor data, or the frequency-shifted sensor signals may be provided to an audio output device through which a test operator may listen to them. Preferably, the frequency-shift module  36  comprises software instructions executed by the processor  18  to perform the frequency-shifting operation. Alternatively, the frequency-shift module  36  comprises digital hardware, such as a programmable matrix array. 
   The frequency-shift module  36  may also be used to digitally downshift ultrasonic signals, such as signals detected by an ultrasonic sensor  12   b . Thus, when reference is made herein to frequency-shifting functions, it will be understood that these functions apply to vibration signal components that are beyond human-audible range as well as to ultrasonic emissions. It will also be appreciated that the frequency-shift module  36  may be used to shift very low frequency vibration signal components up into the audible range. 
   With continued reference to  FIG. 1 , the frequency-shifted audio sensor data may be further processed in an audio processing module  38  before the audio data is stored or provided to an audio output device. In a preferred embodiment, the audio processing module  38  provides a “time-expansion” function to enhance the audibility of repetitive components of the audio signal. For example, a signal that required “X” seconds to record may be played back in “N times X” seconds, where N is some integer such as 4 or 8. In effect, this time-expansion function “slows down” the audio signal so that a test operator or data analyst can more clearly hear and distinguish repetitive patterns, such as would be generated by a bad bearing or defective gears. This function is particularly useful in monitoring the operation of intermediate to high-speed machines, such as those operating at 600 RPM and higher. 
   The audio processing module  38  may also provide an “equalizer” function to allow a test operator or data analyst to amplify selected frequency components in relation to other components so that the selected components can be more clearly heard. 
   A preferred embodiment of the apparatus  10  includes a digital storage device  20  for storing the digital sensor data (step  106  in  FIG. 2 ). For example, the storage device  20  may comprise a magnetic hard disk drive, a flash memory drive or other data storage mechanism. The storage device  20  may also store setup information used in setting up the apparatus  10  for making measurements at particular measurement points along a measurement route. Such setup information may include settings for signal gain, signal offset and display scale, which values may vary from machine to machine along a measurement route. As discussed in more detail below, the storage device  20  also stores audio files containing sound information related to the sensor data, such as vibration or ultrasonic data that has been down-shifted into the audio range and/or time-expanded audio data (step  108  in  FIG. 2 ). A digital data input/output port  22 , such as a USB, IEEE 1394 or RS232 interface, is also provided for uploading and downloading data to and from the storage device  20  of the apparatus  10 . 
   As shown in  FIG. 1 , the apparatus  10  includes a sound sensor  14  for receiving sound and generating analog audio signals based thereon (step  104  in  FIG. 2 ). As used herein, “sound” refers to variations in air pressure within a frequency range which is generally detectable by the human ear. The sound sensor  14  may be integrated into a housing that contains the apparatus  10 , or the sound sensor  14  may be in a separate housing and may be electrically connected to the housing of the apparatus  10  via an audio sensor cable. In some embodiments, the sound sensor  14  is wireless, and communicates with other components of the apparatus  10  via a wireless communication link  28 , such as a Bluetooth link. 
   In some preferred embodiments, the sound sensor  14  comprises a microphone, such as an electret or bone-conduction microphone having noise-canceling capability. Such microphones are well known in the field of voice communications and are used extensively by firefighters, aircraft pilots and others working in high-noise environments. In some applications discussed herein, the sound sensor  14  comprises a directional microphone which an operator may use to detect sound from a desired direction while attenuating sound from undesired directions. 
   The analog audio signals generated by the sound sensor  14  are provided to signal conditioning circuitry  15   c , which may include signal filter, noise canceling, offset and gain stages, as are well known to those skilled in the art. The conditioned analog audio signal at the output of the signal conditioning circuitry  15   c  is provided to an analog-to-digital converter  16   c  which converts the analog audio signal to digital audio data. In preferred embodiments, the digital audio data is then stored in the digital storage device  20  in association with the sensor data (step  108  in  FIG. 2 ). 
   As shown in  FIG. 1 , a preferred embodiment of the invention includes a digital-to-analog conversion circuit  24  for converting digital audio data into analog audio output signals (step  112  in  FIG. 2 ). These analog audio output signals are provided to an audio output device  26  that generates sound signals which may be perceived by the human ear (step  114  in  FIG. 2 ). In one preferred embodiment, the audio output device  26  comprises an audio amplifier circuit and an audio reproduction device, such as audio headphones or an audio speaker. Some preferred embodiments include a wireless link  30 , such as a Bluetooth link, for providing the audio data to the D/A  24  and the audio output device  26 . In one embodiment, the sound sensor  14  and audio output device  26  are combined in a wireless headset, and the wireless links  28  and  30  are combined in a single two-way wireless communication link. 
   The portable machine data collection apparatus  10  preferably includes an input device  32  for receiving input from a user of the apparatus. The input device  32  may comprise a keypad, a touchpad, a touch screen or other known devices for allowing a user to input information and make operational selections. A display device  34  is also provided, such as an LCD or plasma screen, for displaying sensor data and operational information to the user. As indicated above, the display device  34  may be combined with the input device  32  in the form of a touch screen. 
   According to preferred embodiments of the invention, the sound sensor  14  is used to capture audio signals (step  104 ) that are associated with the operation of an industrial machine. These audio signals are preferably captured simultaneously with the capture of sensor data using the sensor  12   a  or the sensor  12   b  (step  102 ). For example, the sensor  12   a  may be a vibration sensor attached to a machine to measure vibration characteristics and to sense machine faults that are manifested in the vibration data. Simultaneously with the measurement of the vibration data, the sound sensor  14  captures sound information associated with the operational characteristics of the machine. The sound information and the vibration information are converted into one or more digital data files and are stored in association with each other on the digital storage device  20  (steps  106  and  108 ). In one exemplary embodiment, the audio data and sensor data are stored in association with information that identifies a particular machine and/or a particular measurement point along a measurement route. 
   In some applications, the apparatus  10  may be used to record voice annotations in association with sensor data. For example, using a sound sensor  14  in the form of a noise-canceling microphone, a test operator may record vocal comments regarding the subject matter of a particular sensor measurement (step  104 ), such as comments regarding the condition of the machine-under-test at the time of the measurement, the location of the sensor on the machine or any other information that later may be useful to a data analyst. These voice annotations are preferably stored as digital audio data in a data file on the storage device  20  (step  108 ), where the data file also includes the collected sensor data, or the data file is identified as being associated with a data file containing the collected sensor data. A noise-canceling microphone is particularly effective in this application to cancel out unwanted noise from the machine under test and background noise from the industrial environment. 
   In some preferred embodiments, verbal instructions or reminders regarding sensor measurements are prerecorded as one or more digital audio files on the storage device  20  of the apparatus  10  (steps  104  and  108 ). These digital audio files are preferably identified as being associated with a particular route point setup file stored on the apparatus  10 . In this way, there may be different verbal instructions or reminders related to different measurement points along a route. When a test operator selects or activates a particular route point setup file on the apparatus  10 , the associated digital audio file is accessed and the recorded instructions or reminders are played for the operator via the audio output  26 . 
   In some preferred embodiments, an audio library of samples of sounds associated with particular kinds of fault conditions may be stored as digital audio files in the storage device  20  (steps  104  and  108 ). Using this feature, when a test operator encounters a machine making an unusual sound, the operator may listen to the samples of known fault sounds stored on the apparatus  10  to compare to the sound made by the machine (steps  112  and  114 ). In this way, the operator can identify the likely fault condition and deduce the most appropriate tests to perform or other actions to take. For example, using the input device  32 , the operator may retrieve a list of known fault conditions for particular machines for which sample sounds have been recorded. This list may be displayed on the display device  34  of the apparatus  10 . Using the input device  32 , the operator may select sounds from the list to be played over the audio output device  26 . Once the operator has identified a sound that most closely matches the sound being generated by the machine under test, the operator may use the input device  32  to select an associated stored test setup routine for initializing the apparatus  10  to collect data for analyzing the fault. In this embodiment, test setup routines for collecting diagnostic data are stored on the storage device  20  in association with digital audio files containing sounds related to the particular fault conditions to be diagnosed. 
   In situations where the measurement sensor  12   b  is an infrared camera, digital infrared image data from the sensor  12   b  may be stored on the digital storage device  20  in association with a standard photographic digital image that was captured at or about the same time as the infrared image. For example, the photographic digital image may be uploaded from a digital camera to the storage device  20  via the data I/O port  22 . In this way, photographic image data and voice annotation data may be stored in association with the infrared image data, thereby providing information to a data analyst in a variety of formats for use in the analysis process. 
   The foregoing description of preferred embodiments for this invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the invention and its practical application, and to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.