Improving the vibration isolation performance of hard mounts for precision equipment

This paper discusses the application of adaptive feedforward control to generate anti-forces in an active hard mount, thereby improving the vibration isolation performance of the mount. The adaptation algorithm is a preconditioned filtered reference least mean squares (FxLMS) algorithm. An integral acceleration feedback controller is used to add artificial damping to the suspension modes and relevant structural modes. Moreover, the feedback control results in a more computationally efficient and faster converging feedforward controller. Simulation and real-time test results on a laboratory setup are presented, which demonstrate the feasibility of the concept.