在工業上, 振動的問題一直存在動態的系統中, 它除了要影響到位置的
準確性外, 它還是造成材料破壞的主要原因之一。所以如何有效消除振動
的問題一直都被討論, 由於振動的來源是一個未知的變數, 所以被動式的
吸收器一直無法很有效的壓制振動.而主動式的吸收器在這方面就有可不
錯的表現, 但是在加入驅動器時, 常常會因為系統的幾何形狀,使得驅動
器不好加入系統, 但在這論文中, 我們所使用的驅動器是壓電材料 可以
是一層覆在原材料的特殊物質, 如此新系統和舊系統在外觀上就沒有什麼
差別, 但在表現上卻大大的不同。

Vibration is a major reason cause the damage on the mechanism
under the allowance stress. So vibration control is coming to
their rescue. Research in dynamic vibration absorbers has yield
several fundamental designs. Among these are tuned dynamic
absorber, these designed utilize certain combination of passive
mechanical element ( springs and dampers)to reduce the
vibrational amplitude of a system. However, with recent advance
in motion sensing and actuating, the design of vibration
absorbers that utilize actively actuated element has become more
attractive. In this paper, we make a simple introduction on
traditional control and provide a method ( active absorber)
include the control law applied on cantilever beam with
piezoelectric.