System and method for detecting cutting tool failure

A system for detecting failure of a cutting tool having a cutting cycle during its operation, the system comprising:

• means for generating a time domain signal based on vibration of the tool during its cutting cycle;
• means for transforming the time domain signal from the time domain to the frequency domain to obtain a frequency domain signal, the frequency domain signal having a plurality of component frequencies;
• means for determining the energy of the frequency domain signal in a plurality of frequency bands based on the of the frequency domain signal at the plurality of component frequencies;
• means for comparing the energy of the frequency domain signal in each of the plurality of frequency bands to corresponding predetermined threshold values, wherein the means for comparing the energy of the frequency domain signal to predetermined threshold values includes means for determining a threshold value for each frequency band based on the cutting cycle;
• and
• means for generating a tool failure signal when the energy of the frequency domain signal in a preselected number of frequency bands exceeds the corresponding threshold values for a predetermined time period.

A method for detecting failure of a cutting tool having a cutting cycle during its operation, the method comprising the steps of:

• generating a time domain signal based on vibration of the tool during its operation;
• transforming the time domain signal from the time domain to the frequency domain to obtain a frequency domain signal, the frequency domain signal having a plurality of component frequencies;
• determining the energy of the frequency domain signal in each of a plurality of frequency bands by summing the squares of the amplitudes of the frequency domain signal at the plurality of component frequencies within each of the plurality of frequency bands;
• comparing the energy of the frequency domain signal in each of the plurality of frequency bands to corresponding predetermined threshold values;
• and
• generating a tool failure signal when the energy of the frequency domain signal in at least two of the frequency bands exceeds the corresponding threshold values for a predetermined time period.

A method for detecting failure of a cutting tool having a cutting cycle during its operation, the method comprising:

• generating a time domain signal based on vibration of the tool during its cutting cycle;
• transforming the time domain signal from the time domain to the frequency domain to obtain a frequency domain signal, the frequency domain signal having a plurality of component frequencies;
• determining the energy of the frequency domain signal in a plurality of frequency bands based on the amplitudes of the frequency domain signal at the plurality of component frequencies;
• comparing the energy of the frequency domain signal in each of the plurality of frequency bands to corresponding predetermined threshold values, wherein comparing the energy of the frequency domain signal to predetermined threshold values includes determining a threshold value for each frequency band based on the cutting cycle;
• and
• generating a tool failure signal when the energy of the frequency domain signal in a preselected number of frequency bands exceeds the corresponding threshold values for a predetermined time period.