Low-frequency broadband multidirectional vibration isolation by piezoelectric smart platform with active control

A high-precision equipment is very sensitive to vibration, even micro vibration. How to isolate the low-frequency broadband multidirectional vibration remains a challenge. As the main component of piezoelectric smart vibration isolation model, the piezoelectric stack consists of a piezoelectric actuator, a piezoelectric sensor, and a rubber layer. The numerical results obtained by the finite element method agree well with theoretical solutions. The vibration attenuates rapidly under displacement and velocity feedback control with negative gains. As the control gain decreases, the vibration isolation band is extended to lower frequency. A piezoelectric smart multidirectional vibration isolation platform model is further proposed by inclined installation of two piezoelectric stacks. A spring-like structure is designed to exert a preload pressure on these piezoelectric stacks. After optimization on the control gain, the platform can isolate vibration from 0 to 3000 Hz in multiple directions.