Abstract: While monitoring the condition of a machine, vibration data is often collected for analysis by an experienced analyst. Systems and methods for analyzing vibration spectra associated with machine condition monitoring are disclosed herein. A system may be configured to collect vibration data from one or more vibration sensors, generate a vibration spectrum of the vibration data, and generate a spectral plot of the vibration spectrum. The system may receive a selection of a region of the spectral plot and generate a modifiable window of the vibration spectrum that is embedded within the spectral plot. The system may display a set of graphing tools along with the modifiable window that enable a user to make modifications to the window. The system may detect the modifications and update the modifiable window accordingly.

Abstract: A process for thinning scalar machine vibration data can reduce the amount of data storage required to store the data by several orders of magnitude, without losing any important machine diagnostic vibration information. The process assumes that because each scalar vibration measurement value has its own range of values, there is a unique delta change in value that does not significantly impact machine diagnostic information provided by the data. Some embodiments provide a method to automatically evaluate the delta change in value. The process can be used to thin data that have already been stored in a database, and also to thin the data in real-time during data collection. Data storage structures for storing the thinned scalar values and processes for displaying a trend plot to indicate where the scalar data have been thinned are also described.

Abstract: A computer implemented method processes time waveform machine vibration data that are indicative of operational characteristics of a machine. The data, which were measured on the machine over a period of time having a begin time and an end time, are accessed from a memory or storage device. An integer number M of waveform samples are determined from the data to be averaged, and an asymptotically decaying DC bias component in the data is derived using a moving average of the M number of waveform samples. The DC bias component is extrapolated from the begin time of the waveform back to an earlier time and from the end time of the waveform forward to a later time. The DC bias component is then subtracted from the time waveform data, and a Fast Fourier Transform is performed on the data to generate a spectrum.

Abstract: An apparatus continually monitors predictive maintenance information and analyzes incoming measurements resulting in recommendations for improving setup information, such as machine information and measurement configurations. Smart sensors generate sensor signals corresponding to the parameters of a machine and a transducer converts the sensor signals into digital sensor data, which is stored into memory. An analyzer determines current operating characteristics of each machine and runs an improvement cycle in which it calculates new setup information. For example, the analyzer may calculate a new alert limit, which is a new measurement configuration that may be saved in the database as a new stored measurement configuration replacing an old measurement configuration. The analyzer may also calculate new machine information.

Abstract: A statistical method is used to separate periodic from non-periodic vibration peaks in machine vibration spectra. Generally, a machine vibration spectrum is not normally distributed because the amplitudes of periodic peaks are significantly large and random relative to the generally Gaussian noise. In a normally distributed signal, the statistical parameter Kurtosis has a value of 3. The method sequentially removes each largest amplitude peak from the peaks in a frequency region of interest in the spectrum until the Kurtosis has a value of three or less. The removed peaks, which are all considered to be periodic, are placed into a candidate peak list. As the process of building the candidate peak list proceeds, if the kurtosis of the remaining peaks in the frequency region of interest falls to three or less, the process stops and the candidate peak list is defined.

Abstract: An apparatus is described that determines an estimated rotational speed of a rotating component of a machine in the absence of a reliable tachometer signal to indicate an actual rotational speed. The apparatus includes a processor that produces a spectral plot of the vibrational data, locates peaks in the spectral plot, and scans the spectral plot in predetermined rotational speed increments to provide candidate rotational speeds. For each candidate rotational speed, associated harmonics are identified, closest peaks in the spectral plot to the candidate rotational speed and its harmonics are located, gaps between the closest peaks and the candidate rotational speed and its harmonics are measured, and a sum of the gaps is recorded. The estimated rotational speed is the candidate rotational speed associated with a minimum sum of the gaps.

Abstract: A method of presenting data, by receiving data from a data source, and storing the data on a non-transient, computer-readable storage medium. A current key performance indicator is calculated from the data, and is added to a file of historical key performance indicators that is stored on the non-transient, computer-readable storage medium/The current key performance indicator is read from the non-transient, computer-readable storage medium, and presented in a first graphical image. The historical key performance indicators are read from the non-transient, computer-readable storage medium, and presented in a second graphical image. The presentation of the current key performance indicator is linked to the presentation of the historical key performance indicators in a composite interface element, such that when a historical position is selected in the second graphical image, the first graphical image depicts a key performance indicator that was current at that historical position.

Abstract: An apparatus is described that determines an estimated rotational speed of a rotating component of a machine in the absence of a reliable tachometer signal to indicate an actual rotational speed. The apparatus includes a processor that produces a spectral plot of the vibrational data, locates peaks in the spectral plot, and scans the spectral plot in predetermined rotational speed increments to provide candidate rotational speeds. For each candidate rotational speed, associated harmonics are identified, closest peaks in the spectral plot to the candidate rotational speed and its harmonics are located, gaps between the closest peaks and the candidate rotational speed and its harmonics are measured, and a sum of the gaps is recorded. The estimated rotational speed is the candidate rotational speed associated with a minimum sum of the gaps.

Abstract: A statistical method is used to separate periodic from non-periodic vibration peaks in autocorrelation spectra. Generally, an autocorrelation spectrum is not normally distributed because the amplitudes of periodic peaks are significantly large and random relative to the generally Gaussian noise. In a normally distributed signal, the statistical parameter kurtosis has a value of 3. The method sequentially removes each largest amplitude peak from the peaks in the spectrum until the kurtosis is 3 or less. The removed peaks, which are all considered to be periodic, are placed into a set. The total energy of the peaks in the set is considered to be the total periodic energy of the spectrum. As the process of building the peak set proceeds, if its total energy becomes greater than or equal to a predefined energy threshold before its kurtosis reaches 3 or less, the process stops and the periodic peak set is defined.

Abstract: A vibration sensor mounting structure improves the stability and repeatability of a measured signal generated by a machine vibration sensor. The structure has an outer annular surface that contacts the machine under test and a shallow recess inside the outer annular surface. The recess causes resonant vibrations of the mounting structure to occur at frequencies that are above the intended measurement range of the sensor. The recess also allows the mounting force to be positioned away from the center mounting screw and onto the more stable outer annular surface. With the mounting force away from the center, lateral forces have less effect on the measured signal.

Abstract: An apparatus continually monitors predictive maintenance information and analyzes incoming measurements resulting in recommendations for improving setup information, such as machine information and measurement configurations. Smart sensors generate sensor signals corresponding to the parameters of a machine and a transducer converts the sensor signals into digital sensor data, which is stored into memory. An analyzer determines current operating characteristics of each machine and runs an improvement cycle in which it calculates new setup information. For example, the analyzer may calculate a new alert limit, which is a new measurement configuration that may be saved in the database as a new stored measurement configuration replacing an old measurement configuration. The analyzer may also calculate new machine information.

Abstract: A computerized apparatus for presenting vibration data that is read under different conditions as a single trend line on a chart. A sensor measures vibration and produces vibration data. A memory stores the vibration data, an indicator of the condition under which the vibration data was produced, and a type associated with the vibration data. A processor reads the vibration data, the condition, and the type from the memory, and selectively plots the vibration data on the trend line when the type of the vibration data matches a given value, even though the condition might be different from data point to data point on the trend line. The processor selectively creates a flag indicating a condition change, and an interface presents a plot of the trend line, and the flag when a condition change occurs between data points.

Abstract: A method for detecting defects in a rotational element of a machine based on changes in measured vibration energy includes: (a) collecting vibration data over an extended period of time using vibration sensors attached to the machine; (b) processing the vibration data to generate a time waveform comprising processed vibration values sampled during sequential sampling time intervals within the extended period of time; (c) detecting multiple time blocks within the extended period of time during which the processed vibration values exhibit sustained increases at progressively increasing rates; and (d) generating alerts based on detection of the multiple time blocks during which the processed vibration values exhibit sustained increases at progressively increasing rates.

Abstract: Spectral machine condition energy peaks are graphically represented in a spectral plot using color coding, different line types, and/or filtering. This allows visual differentiation of spectral peaks associated with various fault frequency families from one another, whereby a machine condition analyst using computer-based analysis software can easily see each family of spectral peaks individually, without all the other spectral peaks, or in combinations of families that are relevant to a machine fault under investigation. In addition to current spectral data, the analyst can also view a historical trend of related scalar parameters plotted in conjunction with current spectral data, wherein the spectral data plot is synchronized with a time-based cursor on the trend plot.

Abstract: While monitoring the condition of a machine, vibration data is often collected for analysis by an experienced analyst. Systems and methods for analyzing vibration spectra associated with machine condition monitoring are disclosed herein. A system may be configured to collect vibration data from one or more vibration sensors, generate a vibration spectrum of the vibration data, and generate a spectral plot of the vibration spectrum. The system may receive a selection of a region of the spectral plot and generate a modifiable window of the vibration spectrum that is embedded within the spectral plot. The system may display a set of graphing tools along with the modifiable window that enable a user to make modifications to the window. The system may detect the modifications and update the modifiable window accordingly.

Abstract: A method for removing the DC disturbance of a vibration waveform, by receiving the vibration waveform and detecting and removing a DC component of the vibration waveform, leaving substantially only an AC component of the vibration waveform, which is stored on a non-transitory computer-readable medium.

Abstract: A method of messaging control is implemented in a plant wide monitoring apparatus. A computer based framework infrastructure communicates with monitoring applications throughout the plant that are implemented on computers, monitors and computer-based applications. Sensors are placed on machinery and monitors receive sensor signals and generate event signals in response to defined physical occurrences, such as when vibration in a machine is exceeding a defined limit or a sensor is failing. A messaging application in the framework infrastructure generates messages corresponding to the event signals. The messages are transmitted to users based on send rules and suppression rules, which are user configurable. The send rules identify messages to be sent or not sent to a particular user based on characteristics of event signals. The suppression rules prevent the transmission of a message based on both the content of a particular event signal plus an external factor, such as a prior event signal.

Abstract: A vibration analyzer for use in determining a rotational speed. The vibration analyzer includes: a) an input for sensing vibration data, b) a memory for storing the vibrational data, and c) a processor. The processor 1) produces a spectral plot of the vibrational data, 2) locates peaks in the spectral plot, 3) inputs a rotational speed, and 4) scans the spectral plot in predetermined rotational speed increments to provide a candidate rotational speeds. For each candidate rotational speed i) a number of associated harmonics is identified, ii) closest peaks in the spectral plot to the candidate rotational speed and its harmonics are located, iii) gaps between the closest peaks and the candidate rotational speed and its harmonics are measured, iv) summed, and a sum of the gaps is recorded. In step (5) The candidate rotational speed that is associated with a minimum sum is selected as the nominal rotational speed.

Abstract: A method for filling a gap of missing vibration data in a set of vibration data. At least one reference waveform on a first side of the gap is selected and at least one adjacent waveform on an opposing second side of the gap is selected. It is determined whether the gap is in a section of the vibration data where a frequency of the vibration data is one of increasing, decreasing, and steady state. Where the gap is in a section of the vibration data where the frequency of the vibration data is changing substantially linearly, an analytical method is applied to at least one of the at least one reference waveform and the at least one adjacent waveform to approximate the vibration data that is missing in the gap.

Abstract: A computer-implemented process determines, based on bearing fault frequencies, optimum values for the maximum frequency (Fmax) and the number of lines of resolution (Nlines) to be used in collecting machine vibration data so as to adequately distinguish between spectral peaks for identifying faults in machine bearings. The process can be extended to any other types of fault frequencies that a machine may exhibit, such as motor fault frequencies, pump/fan fault frequencies, and gear mesh fault frequencies. Embodiments of the process also ensure that the time needed to acquire the waveform is optimized. This is particularly useful when collecting data using portable vibration monitoring devices.