The eigenmodes of the first three eigenfrequencies of the elastic car body are displayed in Fig. 2.
For a given heavy metro vehicle the elastic deformations of the car body are modeled by 17 eigenmodes with eigenfrequencies in the range from 7Hz up to approximately 25Hz and as many FRMs as actuators.
The eigenfrequencies of the FRMs range from approximately 150 to 700Hz, which is necessary to accurately describe highly localized deformations.