Active Vibration Control on the OSU Flexible Beam

The idea of actively damping vibrations in flexible structure systems has received much attention in recent years. Such systems present a particular problem in that there is no fixed frame of reference for actuation; actuators must then be mounted on the structure itself. Currently at Ohio State a laboratory facility is being developed to study control of flexible structures; one specific configuration is a six foot free-free beam which is suspended from the ceiling. Such a beam can be controlled by applying torques about the bending axis or by applying transverse forces. Due to the size constraints of such a laboratory-scale experiment, a small structure with small actuators and sensing devices are utilized. Transverse actuators (developed in-house) were chosen for the experiment, and sensing is accomplished via several sets of strain gauges and accelerometers mounted on the structure. This paper discusses issues involved with the modeling of this structure, and presents a brief summary of the various control approaches, primarily from a decentralized viewpoint, which are currently being applied to the laboratory setup.