Controller design methodologies based on a single controller are often unable to provide both high performance (i.e., tracking bandwidth) and desired robustness (i.e. retaining stability) in the presence of uncertainty or plant variation. This paper presents a hybrid control strategy 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 makes an adaptive controller active for high performance after sufficient plant information has been collected on-line. To avoid a degraded transient after controller switching, a bumpless transfer scheme is designed and incorporated into this hybrid control strategy. This bumpless transfer design is a novel extension from a conventional latent tracking bumpless transfer design for a SISO plant with 1 DOF controllers to either a SISO plant with multiple DOF controllers or a MIMO plant. Experimental results implemented on an active vibration isolation testbed demonstrate the effectiveness of the hybrid control strategy including the bumpless transfer design.

This content is only available via PDF.
You do not currently have access to this content.