Distributed Aerostructural Sensing and Control

Armstrong researchers are investigating ways to increase aircraft maneuverability, safety, and fuel efficiency by the application of networks of smart sensors distributed across an aircraft. This "fly by feel" concept could enable a vehicle to autonomously react to changes in aerodynamic and structural conditions through the use of distributed pliable membrane sensors that obtain real-time information and convert it into aerodynamic information that can be used for adaptive flight control. In comparison with conventional sensing technologies, which measure aerodynamic parameters from an aircraft's fuselage only, these smart sensors enable localized measurements at nearly any surface on an aircraft structure. For example, hot film sensors could be placed at wing transition points to measure shear stress or along the leading edge of a wing to measure velocity and angle of attack. The ultimate goal is to feed real-time sensor information into a control scheme such that the aircraft can autonomously control the position of a surface appropriately for active aeroelastic wing control. Work to date: The team is conducting sensing and analysis work with hot film sensors: 1) wind tunnel tests at Texas A&M University on a wing outfitted with hot film sensors and subjected to wind gusts 2) hot film sensors on the leading edge of a Gulfstream III wing to measure transitions between the leading edge and the control flap 3) wind tunnel tests on a wing section of the X56 aircraft 4) hot film sensors installed on the leading edge of an F18 aircraft. Looking ahead: Next steps involve more investigative work with the X56 aircraft, specifically hot film sensors combined with fiber optic strain sensing and associated data fusion algorithms to address distributed sensing and control applications. Partners: Texas A&M University for wind tunnel tests, California Institute of Technology for computational studies augmented with Illinois Institute of Technology wind tunnel tests, University of Minnesota Aerospace Engineering and Mechanics for distributed aeroelastic control Benefits Autonomous: Could enable real-time performance-based measurements Accurate: Could permit revolutionary capabilities across a wide speed range, including but not limited to shorter takeoff and landing even to near-stall conditions, safe and reliable supersonic operation, larger passenger and cargo capacity over increased range Improved safety: Provides localized data, enabling engineers to be more confident that design specifications offer appropriate safety margins Certifiable performance and stability guarantees Aerostructural efficiency Applications Aircraft testing and design Vortex interaction for formation flying and increased landing density at airports Improved drag reduction and increased lift performance Active aeroelastic control of flexible structures