Active Isolation of a Vibrating Mass

Active vibration isolation can offer improved performance at low frequencies compared with passive isolation. Active control methods require the selection of a suitable cost function to be minimised. Experimental results are presented of the active vibration isolation of a simulated rotating machine mounted to a beam which uses two types of cost function, the force and acceleration respectively at the base of the isolator. The results show that minimisation of one type of cost function does not necessarily lead to the minimisation of the other cost function