Computational Systems, Inc.

John W Willis

Anthony John Hayzen

Christopher G Hilemon

William E Childress

Deane M Horn

Michael D Medley

Stewart V Bowers, Iii

Richard W Kephart

Kevin D Steele

A vibration data collection device monitors vibration of a machine, generates original machine vibration waveform data based on the monitored vibration, and removes portions of the original machine vibration waveform data that do not indicate an occurrence of a vibration event related to a potential fault in the machine. The vibration data collection device then stores thinned waveform data that includes blocks of the original machine vibration waveform data and excludes the portions that have been removed. A data analysis computer generates a thinned waveform plot based on the thinned waveform data. In some embodiments, the thinned waveform plot includes the blocks of original machine vibration waveform data separated in time by gaps representing the portions that have been removed. In some embodiments, the thinned waveform plot that includes the blocks of the original machine vibration waveform data and representative blocks of data that each represent the portions of the original machine vibration waveform data that have been removed. A display device displays the thinned waveform plot for viewing by an analyst.

Graphical display of discontinuous waveform data

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.

Vibration spectra window enhancement

A sensor signal conditioning circuit of a machinery health monitoring module is disposed between a machine sensor and an analog-to-digital converter (ADC). The circuit includes a sensor interface connector, first and second operational amplifiers, a Nyquist filter, and first and second gain flattening feedback networks. The interface connector can connect to multiple types of sensors for monitoring various machine characteristics. The output of the first operational amplifier is coupled to the positive input of the ADC, and the output of the second operational amplifier is coupled to the negative input of the ADC. The first operational amplifier provides a high impedance differential interface to the analog sensor signal and a low impedance interface to the positive input of the ADC. The second operational amplifier provides an inverted copy of a signal at the positive input of the ADC and a low impedance interface to the negative input of the ADC.

Sensor power control and signal conditioning circuit for machinery monitoring system

A sensor power controlling circuit of a machinery health monitoring module includes (1) a positive voltage input for receiving a positive voltage from a galvanically isolated voltage source within the machinery health monitoring module, (2) a sensor power connecter for providing power to a machine sensor, (3) a push-pull comparator having a positive input, a negative input, and an output, (4) a first resistor, (5) a PNP transistor, and (6) a first capacitor. A sensor signal conditioning circuit of the machinery health monitoring module is disposed between a machine sensor and an analog-to-digital converter (ADC). The sensor signal conditioning circuit includes a sensor interface connector, a first and second operational amplifier, a passive Nyquist filter, and first and second gain flattening feedback networks.

A machine monitor includes sensors producing a series of scalar values corresponding to sensed physical parameters. An analyzer produces a first database based on the scalar values and determines a median value of the scalar values for each sensor. It also sets a spike level that is offset from the median value by a predetermined multiple of the median value. A spike filter in the analyzer compares the scalar values to the spike level, and identifies a particular scalar value as a potential spike when the particular scalar value differs from the median value by an amount that is equal to or greater than the spike level. A potential spike is determined to be an actual spike if the first and second side values are within a predetermined range of the median value. A second database is produced with the actual spikes eliminated. Using the second database, corrected faults are identified by finding a data point that exceeds a danger level with a preceding data point exceeding a warning level and two trailing data points being less than an advise level.

Detection of spikes and faults in vibration trend data

A universal sensor interface for a machine data acquisition system includes a sensor power control circuit that: (1) provides a fast and accurate limiting response to a short-circuit fault, (2) survives and automatically recovers from multiple concurrent continuous short-circuit faults with no interruption to the electrical and thermal integrity of the acquisition system, (3) reduces power consumption/dissipation when in a faulted condition, (4) isolates adverse effects of a faulted channel from uninvolved channels, (5) isolates adverse effects of loose wiring termination 'chatter' from uninvolved channels, (6) protects against adverse effects resulting from 'hot wiring' of sensors, (7) protects the acquisition system against reasonably anticipated installation wiring errors, and (8) minimizes the availability of spark-inducing energy to the data acquisition system.

Universal sensor interface for machinery monitoring system

A field programmable gate array (FPGA) in a machine health monitoring (MHM) module includes interface circuitry, vibration data processing circuitry, and tachometer data processing circuitry. The interface circuitry de-multiplexes a synchronous serial data stream comprising multiple multiplexed data channels, each containing machine vibration data or tachometer data, into separate input data streams. The vibration data processing circuitry comprises parallel processing channels for the separate input data streams containing vibration data, each channel including a highpass filter, two stages of integration circuits, a digital tracking bandpass filter, and multiple parallel scalar calculation channels. The tachometer data processing circuitry processes the tachometer data to generate RPM and other values. A cross-point switch in the FPGA distributes tachometer signals between MHM modules in a distributed control system, thereby allowing multiple modules to share tachometer information.

Parallel digital signal processing of machine vibration data

A system is described for time synchronizing digitized measurement signals, such as vibration signals. The digitized signals, which are acquired asynchronously by multiple distributed measurement units, indicate the operational condition of a machine or a process. To measure the phase of the digitized signals relative to a pulse tachometer input, the time between the leading edge of the tachometer pulse and the digitized samples is measured. To achieve phase-coherent synchronization across the distributed measurement units, a local synchronization signal is embedded into the data produced by the measurement units. The systems uses the synchronization signal to align the data in post processing, which phase aligns the data and aligns the data in absolute time. The synchronization signal may be encoded with a timestamp to provide additional timing information.

Apparatus and method for signal synchronization

A vibration data acquisition and analysis module is operable to be inserted directly into a distributed control system (DCS) I/O backplane, so that processed vibration parameters may be scanned directly by the DCS I/O controller. Because the process data and the vibration data are both being scanned by the same DCS I/O controller, there is no need to integrate numerical data, binary relay outputs, and analog overall vibration level outputs from a separate vibration monitoring system into the DCS. The system provides for: (1) directly acquiring vibration data by the DCS for machinery protection and predictive machinery health analysis; (2) direct integration of vibration information on DCS alarm screens; (3) acquisition and display of real time vibration data on operator screens; (4) using vibration data to detect abnormal situations associated with equipment failures; and (5) using vibration data directly in closed-loop control applications.

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Oak Ridge, TN, United States of America

John W Willis