Inverse and forward kinematic models have been developed for multi-DOF shaking tables. These are essential for the translation of kinematic data ( displacement, velocity and acceleration ) between table and actuator axes. The analytical background to the MCS algorithm has been developed for shaking table applications, involving two types of retrofit strategies. These have allowed MCS to be implemented on a shaking table controller facility without the need to remove the existing controller. Two schemes were identified as the 'inner-loop' and 'outer-loop' strategies.
The concept of composite filters has been developed with details of each type of filter. The purpose of composite filters is to combine kinematic data measurements into a single 'optimal' estimate of the required signal. In particular, displacement and acceleration responses have been combined into a better estimate of displacement over a 0-30Hz frequency range. This composite filtering technique has also been shown to be valuable in the generation of demand data, e.g. for the generation of displacement demand from pre-recorded seismic acceleration data.
A software package TABCTRL ( Table Control ) has been developed for the adaptive control of multi-axis shaking tables. Using MCS, new research areas have been developed in non-linear behaviour of test pieces, multi-support input, sub-structuring on shaking tables and the effect of spurious motions.