Experimental Demonstration of Fiber Bragg Grating Strain Sensors for Structural Vibration Control

We report on the use of a high-speed wavelength division multiplexing (WDM) technique for multiplexing Fiber Bragg Grating (FBG) sensors applied to structural Vibration Control for the measurement of strain, permitting many sensing devices along a single optical fiber at different locations collecting samples at 5000 Hz with microstrain resolution. In this demonstration, a cantilevered flexible aluminum beam is used as the object for vibration control. A piezoceramic patch surface-bonded to the cantilevered end of the beam is used as an actuator to suppress the beam vibration. Various active vibration controllers such as positive position feedback (PPF), strain rate feedback (SRF), proportional plus derivative (PD), pole placement, and sliding mode based robust control are tested by using the fiber optical sensor for feedback purpose. Experiments successfully demonstrate that the signals from the fiber optic sensor can be used for active feedback control of the beam vibration.