Practical compensation for reaction force with specific frequency in shaking tables

This paper presents a practical control methodology of shaking tables for earthquake simulators. Reaction force generated by a specimen on the shaking table generally deteriorates motion performances of the table, resulting in the lower control accuracy in seismic tests. In order to provide the precise table motion, therefore, a 2-degrees-of-freedom control structure is adopted, where the reaction force generated by the specimen on the shaking table can be compensated, and the table control accuracy can be improved. The proposed compensation algorithm has been verified by experiments using a prototype of shaking table.