Multiple Shaker Random Vibration Control--An Update

The theory of the control of multiple shakers driving a single test item is reviewed. Several improvements that have been introduced since the original papers on the subject will be discussed. The improvements include: (1) specification of the control spectra; (2) the control of non-square systems (the number of shakers does not have to be equal to the number of control points); (3) the connection between sine testing, waveform control, and random control; (4) improvements in feedback control; (5) overlap-add versus time domain randomization; and (6) reproduction of non-Gaussian waveforms