Abstract: A system and method for monitoring vibrations of a cutting tool produced by tool break events, and for interpreting them to detect tool breaks of sufficient magnitude to endanger the machined part. The signal generated by a sensor such as an accelerometer is preprocessed to attenuate low frequency machining noise and detect the energy in a higher frequency band, then sampled, and the digitized signal samples analyzed by tool break detection logic. This logic is triggered by a positive-going signal transient, and prevents false alarms on minor tool break events that do not mar the workpiece and on noise from other sources.

Abstract: When a torque is transmitted through a body, the body tends to twist in proportion to the torque and to the characteristics of the material. Doppler measurements made at points separated from each other on a body differ slightly due to the applied torque by the reduced motion of the body at points closer to the load. The Doppler from the two points is accumulated to thereby maintain a record of the twist and thereby the torque in the body.