F-15 Active a Flexible Propulsion Integration Testbed

Abstract

NASA Dryden, together with Lhc US. Air Force, McDonnell Douglas Aerospace, and Pratt & Whitney, arc developing a test aircraft capable of flight demonstrating a wide spectrum of aerodyriamic and propulsion Integration technologies for future commercial aud military aircrralt. The features of this testbed, the F-15 hdvnticcd Control Technology for IntegratedVchiclcs, or ACTIVE, are described, togctfier wih a summary of thc programs planned to be demonstrated.The aircraft is equipped with two axisymmctric pitch ,and yaw thrust vectoring nozzles, a quadruplex digital integmtcd flight propulsion control system, a high throughput/ high memory Vehicle Management System Computer, two Electronic Air Inlet Controllers, and two Improvcd Digital Electronic Engine Controls. 'These electronic controls arc fully integrated via five 1553 Multiplex busscs. Ilhc ACTIVE testbed will initinliy be used to demonstrate performance improvemcnts from thrust vectoring and For quantifying the jet intcrnction cffects generated by thrust vectoring. In futurc programs, tliis state-of-the-art testbed will demonstratc ;i sdf-repairing neural network flight control, ttie ability of vectoring nozzles to eliminate vertical tails, anti it multi-variable fully intcgratcd aerodyrianiic and cnginc control. Tlie fully integrated flight, propulsion, and vehicle management computers make this aircraft a unique resource for future integration testing. -1 ACTIVE AdAPT A8 A9 BRN RC cc EAIC FC 1;7..,IR g J Nomenclature -Advanced Control Technology for htcgrated Veh ides

Real-Time Dynamic Modeling: Data Information Requirements and Flight-Test Results

“…(15)(16)(17) are applied to frequency-domain data at selected times, normally at regular time intervals. The frequency-domain data must therefore be available at any time, and so the Fourier transforms are computed using a recursive Fourier transform, described in Sec.…”

“…The parameter estimation and covariance calculations in Eqs. (15)(16)(17) can be done at any time, but are usually done at 1 or 2 Hz to save computations. Linearized aerodynamic characteristics rarely change faster than this, except in cases of strong nonlinearity, damage, failure, or rapid maneuvering.…”

“…The thrust vectoring feature, however, was not used during the flight testing described here. Further information on the modified F-15B aircraft and associated flight-test operations can be found in [16].…”