Determination of stiffness and damping sensitivity for computer numerically controlled machine tool drives

A generalized eigenvalue method is used to determine the undamped and damped natural
frequencies, coefŽ cients of damping and mode shapes of a computer numerically controlled (CNC)
machine tool drive. The calculated results compare well with the measured results obtained by using
vibration analysis equipment. Then the sensitivity of the various modes to changes in the stiffness and
damping characteristics of the machine drives is estimated. These values prove to be useful in
adjusting the parameters of a hybrid model for a CNC machine tool axis drive in order to alter the
simulated results in accordance with the measured results.