Determining machine operating conditioning based on severity of vibration spectra deviation from an acceptable state

A method of evaluating the operational condition of a machine when the machine's vibration spectrum deviates from an acceptable state, the acceptable state being defined by an alarm limit envelope, the method comprising the steps of:

• determining the vibration spectrum of the machine, the vibration spectrum characterizing an operational condition of the machine;
• determining the alarm limit envelope which represents a maximum vibration level above which a peak in the machine's vibration spectrum is considered abnormal;
• comparing the amplitude of individual peaks within the machine's vibration spectrum to the alarm limit envelope;
• and
• determining a deviation severity value based upon said comparing, the deviation severity value characterizing the severity of deviation from an acceptable state when at least one individual peak within the machine's vibration spectrum exceeds the alarm limit envelope, said determining comprising the following steps:
• determining the peak excess magnitude for each vibration peak within the machine's vibration spectrum, the peak excess magnitude being the amount by which the amplitude of each deviating vibration peak within the machine's vibration spectrum exceeds the alarm limit envelope level;
• normalizing the peak excess magnitude with a normalization factor, the value of the normalization factor being dependent on the frequency of the vibration peak;
• and
• evaluating the deviation severity value for the machine's vibration spectrum based at least in part upon the normalized peak excess magnitude.

A method of evaluating the operational condition of a machine when the machine's vibration spectrum deviates from an acceptable state, the acceptable state being defined by an alarm limit envelope, the method comprising the steps of:

• determining the vibration spectrum of the machine, the vibration spectrum characterizing an operational condition of the machine;
• determining the alarm limit envelope which represents a maximum vibration level above which a peak in the machine's vibration spectrum is considered abnormal;
• selecting individual vibration peaks within the machine's test vibration spectrum, the frequencies of the selected vibration peaks being integer multiples of each other;
• summing the energy levels associated with the selected vibration peaks, resulting in a sum peak level;
• comparing the amplitude of the sum peak level to the alarm limit envelope;
• and
• determining a deviation severity value based upon said comparing, the deviation severity value characterizing the severity of the deviation of the machine's operational condition from an acceptable state.

A method of evaluating the operational condition of a machine when the machine's vibration spectrum deviates from an acceptable state, the acceptable state being defined by an alarm limit envelope, the method comprising the steps of:

• determining the vibration spectrum of the machine, the vibration spectrum characterizing an operational condition of the machine;
• determining the alarm limit envelope which represents a maximum vibration level above which a peak in the machine's vibration spectrum is considered abnormal;
• selecting individual vibration peaks within the machine's test vibration spectrum, the selected vibration peaks being related to each other as sideband peaks;
• summing the energy levels associated with the selected vibration peaks, resulting in a sum peak level;
• comparing the amplitude of the sum peak level to the alarm limit envelope;
• and
• determining a deviation severity value based upon said comparing, the deviation severity value characterizing the severity of the deviation of the machine's operational condition from an acceptable state.

A programmable apparatus for evaluating the operational condition of a machine when the machine's vibration spectrum deviates from an acceptable state, the acceptable state being defined by an alarm limit envelope, the apparatus comprising:

• a memory which receives and stores a data set representing the alarm limit envelope, and which receives and stores a data set representing the machine's vibration spectrum;
• a processor which receives the data set representing the alarm limit envelope from said memory, receives the data set representing the machine's vibration spectrum from said memory, compares the amplitude of individual peaks within the machine's vibration spectrum to the alarm limit envelope spectrum, and determines a deviation severity value representing the severity of deviation when at least one individual peak within the machine's vibration spectrum exceeds the alarm limit envelope, said processor determining the deviation severity value by determining the peak excess magnitude for each vibration peak within the machine's vibration spectrum, the peak excess magnitude being the amount by which the amplitude of each deviating vibration peak within the machine's vibration spectrum exceeds the alarm limit envelope level, determining the ratio of the peak excess magnitude to the alarm limit envelope level, and evaluating the deviation severity value for the machine's vibration spectrum based upon both the peak excess magnitude and the ratio of the peak excess magnitude to the limit envelope level.

A programmable apparatus for evaluating the operational condition of a machine when the machine's vibration spectrum deviates from an acceptable state, the acceptable state being defined by an alarm limit envelope, the apparatus comprising:

• a memory which receives and stores a data set representing the alarm limit envelope, and which receives and stores a data set representing the machine's vibration spectrum;
• a processor which receives the data set representing the alarm limit envelope from said memory, receives the data set representing the machine's vibration spectrum from said memory, compares the amplitude of individual peaks within the machine's vibration spectrum to the alarm limit envelope spectrum, and determines a deviation severity value representing the severity of deviation when at least one individual peak within the machine's vibration spectrum exceeds the alarm limit envelope, said processor determining the deviation severity value by determining the peak excess magnitude for each vibration peak within the machine's vibration spectrum, the peak excess magnitude being the amount by which the amplitude of each deviating vibration peak within the machine's vibration spectrum exceeds the alarm limit envelope level, normalizing the peak excess magnitude with a normalization factor, the value of the normalization factor being dependent on the frequency of the vibration peak, and evaluating the deviation severity value for the machine's vibration spectrum based at least in part upon the normalized peak excess magnitude.