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, coefficients 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.