PIEZOELECTRIC ACTIVE VIBRATION ISOLATION MECHANISM AND METHOD OF REDUCING THE INHERENT FREQUENCY OF A VIBRATION SYSTEM THEREOF

摘要

A piezoelectric active vibration isolation mechanism comprises a first force sensor (23b), a spring bellows (27), a middle mass block (26), a first flexible hinge (22b), a piezoelectric actuator, a second force sensor (23a), a second flexible hinge (22a) and a controller, one end of the first force sensor (23b) being used for connecting a base platform (28), and the other end thereof being connected sequentially to the spring bellows (27), the middle mass block (26), the first flexible hinge (22b), the piezoelectric actuator, the second force sensor (23a) and the second flexible hinge (22a). The first force sensor (23b) and the second force sensor (23a) are respectively used for detecting vibration signals of the base platform (28) and of a loading platform (21), and respectively transmitting the detected vibration signals to the controller so that the controller controls the piezoelectric actuator to apply a force onto the loading platform (21), thereby compensating the loading platform (21). The piezoelectric active vibration isolation mechanism utilizes a two-stage series-connected suspension structure, effectively reducing the inherent frequency of the structure and being able to effectively suppress low-frequency interference of the slight vibration in a precision device. A method of reducing the inherent frequency of a vibration system is further disclosed.