Modeling and active damping of structural vibrations in machine tools

The positioning accuracy of the high speed machine tools is determined by the bandwidth of servo controllers, which is mainly limited by the structural vibrations that are transmitted to the control loop. This paper presents modeling of machine tool structures and their active damping in the feed drive control loop. The fundamental modes of the machine tool structure that affect the controller are identified. A high bandwidth, sliding mode controller is simulated and experimented on a machine with and without active damping. It is shown that the vibrations can be actively damped, and the bandwidth of the drive can be increased.