MAIN RESEARCH AREAS
Aircraft Modeling, Parameter Identification, and Simulation
FCSL has an extensive background in aircraft parameter identification and the modeling of aircraft sub-systems such as actuators, engines, and sensors. FCSL researchers are currently involved in conducting a detailed PID study for determining the mathematical models of the YF-22 and the Phastball aircraft, under both nominal and actuator failure flight conditions. Flight data for the PID study comes from different aircraft configurations including nominal ‘healthy’ condition as well as ‘failure’ conditions – failures on left stabilator and left aileron (locked at the trim position), and failure on the left engine. During each flight for collecting data for PID, actuator doublets were injected by either the pilot or the on-board computer to excite various aircraft dynamic modes. With data collected under the nominal flight condition, a linear mathematical model of the ‘healthy’ aircraft is first identified. The relationship from the coefficients of the linear model to the values of the aerodynamic derivatives and geometric-inertial parameters are then used for calculating initial values for each of the aerodynamic derivatives. A nonlinear programming tool is then used to iteratively minimize the difference between the flight data and simulated aircraft outputs, leading to a refined nonlinear aircraft model.
Following the PID effort for the nominal aircraft, a linear identification effort is conducted using flight data under actuator failure flight conditions. Within this model, the primary control surface pairs are divided into their left and right components. A new set of aerodynamic coefficients due to the coupling effect is then introduced into the nonlinear aircraft model. Following a similar optimization process as used in the nominal model identification, a detailed nonlinear aircraft model is identified with coupled longitudinal and lateral-directional dynamics, as well as decoupled left/right control surface inputs.
Merceruio, Z., Phillips, K., Gu, Y., Gururajan, S., and Napolitano, M.R., “Aerodynamic and Thrust Force Modeling for a Propulsion Assisted Control Aircraft Test Bed,” 2011 AIAA Atmospheric Flight Mechanics Conference, Portland, OR, August, 2011.
Gross, J., Gu, Y., Rhudy, M.*, Barchesky, F., and Napolitano, M.R. “On-line Modeling and Calibration of Low-Cost Navigation Sensors,” 2011 AIAA Modeling and Simulation Technologies Conference, Portland, OR, August, 2011.
Phillips, K., Gururajan, S., Campa, G., Seanor, B., Gu, Y., and Napolitano, M.R., “Nonlinear Aircraft Model Identification and Validation for a Fault-Tolerant Flight Control System,” 2010 AIAA Atmospheric Flight Mechanics Conference, Control ID#: 809261, Toronto, Ontario, Canada, Aug. 2-5, 2010.
Phillips, K., Campa, G., Gururajan, S., Seanor, B., Napolitano, M., Gu, Y., Fravolini, M., “Parameter Identification for Application within a Fault-Tolerant Flight Control System”, AIAA Atmospheric Flight Mechanics Conference, AIAA-2009-5723, Aug. 10-13, 2009, Chicago, IL, USA.