Active damping of the 1D rocking mode

Active damping of a rotational vibration mode in the linear guidance of a precision machine in a one dimensional (1D) setting is considered in this paper. This so-called rocking mode presents itself in machines having linear actuation. The limitation this vibration mode imposes on the machine precision and closed-loop bandwidth can be overcome by means of active damping. Implementing active damping in a collocated fashion in combination with a passive control algorithm guarantees the robust stability of the system. Active damping control operates in parallel with the motion controller if one is present. These controllers operate completely independently of each other. The overall result is that a higher bandwidth can be achieved for the closed-motion-loop involving the actively damped plant. This improves the performance of the machine in terms of response time, settling time and steady-state and/or set-point error.