Vibration Isolation with High Strain Shape Memory Alloy Actuators: Case of the impulse disturbance

Shape Memory Alloys (SMA's) are generally considered to be a slow and imprecise means of actuation. With the SMA actuator designed at McGill University we wish to show the contrary. In this paper, several SMA actuators are used to actively damp an external impulse disturbance on a mass to be isolated from vibrations. The vibration isolation testbed consists of a `strong' actuator to low-pass the system and a `fast' antagonistic pair to attenuate the remaining disturbance. Both damping systems use the same basic actuator architecture. A variable structure controller switching on the acceleration error and the jerk is effectively used to dampen out an impulse disturbance within 360 msec.