PhD Defence Sil Spanjer | Active Vibration Isolation, an Integrated Approach to Optimal Performance and Robust Adaptation

Active Vibration Isolation, an Integrated Approach to Optimal Performance and Robust Adaptation

Sil Spanjer is a PhD student in the Department of Precision Engineering. (Co)Promotors are prof.dr.ir. W.B.J. Hakvoort and dr. H. Koroglu from the Faculty of Engineering Technology.

The suppression of disturbances is critical to the performance of precision machines. These disturbances can have a multitude of sources, such as parasitic actuator forces, acoustics or floor vibrations, and can be divided into direct and indirect disturbances. Direct disturbances act directly on the sensitive part of the precision machine, and indirect disturbances act through the suspension. Passive isolation systems can be designed to suppress these disturbances. However, direct and indirect disturbances pose conflicting demands on the suspension design. This directly leads to a performance limit for passive suspensions. This performance limit becomes more prevalent due to the ever increasing performance objectives of precision machines, and can be mitigated by adding active elements to the suspensions. These can be used to implement control methods to suppress disturbances. This allows more design freedom and can improve the total disturbance suppression of the precision machine by cancelling measurable disturbances and suppressing unmeasurable disturbances. These active elements, however, also introduce additional noise sources that can be detrimental to the performance. This dissertation develops systematic methods for the system and control design and optimisation of active vibration isolation systems, together with practically implementable and predictable methods to compensate for changes in the disturbances and the dynamics of the system. The methods developed in this dissertation result in more reproducible and optimal results, replacing designer and heuristics with the ability to define relevant targets, physical constraints and insightful frequency-domain analysis.