Performance of optical sensors in the control of flexible structures

This paper demonstrates the use of embedded single-mode optical fibers in the active control of smart structures. The experimental prototype structure, a composite lattice configuration fashioned from graphite/bismaleimide laminate, exhibits complex bending and torsional modes, and forms a sub-scale model of a similar structure being analyzed at the Air Force Astronautics Laboratory. Simulations that include effects of Gaussian observation and process noise on a linear quadratic regulator/ loop transfer recovery (LQG/LTR) controller for active vibration damping are presented. The fiber-optic sensor demonstrates advantages over conventional strain gage sensors in terms of reduced sensitivity to sensor placement, reduced problems with observation and control spillovers, and improved control stability.