Method and apparatus for actively adjusting and controlling a resonant mass-spring system

摘要

An actively-controlled resonant-type force generator (20) is adapted to be attached to a structure (21), and includes a mass (23) mounted for movement relative to the structure and a plurality of springs (22, 24) operatively arranged between the mass and the structure. A servoactuator (26) is arranged to controllably excite the mass-spring system. The actual force (Fa) transmitted from the mass to the structure is compared with a commanded force (Fc) to produce a force error signal (Fe). The actuator is caused to produce a velocity as a function of the error signal. The gain of the closed force loop is selected so that the resonance of the mass-spring system has an effective damping ratio ( zeta ) greater than about 0.5, and preferably about 0.7. Thus, the mass-spring system will not be substantially resonantly excited by vibrations of the structure near its resonant frequency ( omega n).