A hybrid control strategy for active vibration isolation with electrohydraulic actuators

This paper presents a hybrid control approach to circumvent the basic trade-off between performance and robustness from an individual controller. This hybrid control strategy utilizes a robust controller for guaranteed robustness when the plant model is not well known, and employs an adaptive controller for high performance after sufficient plant information has been collected. To avoid a degraded transient after controller switching, a bumpless transfer scheme is designed and incorporated into this hybrid control approach. This bumpless transfer design is an extension from a conventional latent tracking bumpless transfer design for a single-input single-output (SISO) plant with 1 degree of freedom (DOF) controllers to either a SISO plant with multiple DOF controllers or a multi-input multi-output (MIMO) plant. Experimental results implemented on an active vibration isolation testbed demonstrate the effectiveness of the proposed hybrid control strategy.