Fluidic valves based on the Coand\u{a} effect are increasingly being
considered for use in aerodynamic flow control applications. A limiting factor
is their variation in switching time, which often precludes their use. The
purpose of this paper is to demonstrate the closed-loop control of a recently
developed, novel piezo-fluidic valve that reduces response time uncertainty at
the expense of operating bandwidth. Use is made of the fact that a fluidic jet
responds to a piezo tone by deflecting away from its steady state position. A
control signal used to vary this deflection is amplitude modulated onto the
piezo tone. Using only a pressure measurement from one of the device output
channels, an output-based LQG regulator was designed to follow a desired
reference deflection, achieving control of a 90 m/s jet. Finally, the
controller's performance in terms of disturbance rejection and response time
predictability is demonstrated.Comment: 31 pages, 23 figures. Published in AIAA Journal, 4th May 202
