Abstract
Highly maneuverability fighter aircrafts are equipped with various weapons for successful air-to-air and air-to-ground missions. The aircraft has abrupt transient response due to ejection force generated when store of one wing is launched and the movement of lateral center-of-gravity (YCG) changing by the mass distribution of both wings after launched. Under maintaining 1 g level flight with manual trim system in the asymmetric store configuration, the aircraft causes unexpected roll motion for the pure longitudinal maneuver because the change of AoA and airspeed changes the amount of trim for level flight of the aircraft. For this reason, the pilot should continuously use the roll control stick input to maintain level flight. This characteristic increases the pilot’s workload and adversely affects the flying qualities of the aircraft, which is a major cause of deteriorating mission efficiency for combat maneuver. In this paper, we propose a hybrid control that combines model- and sensor-based Incremental Nonlinear Dynamic Inversion (INDI) control based mathematical model of the supersonic advanced trainer to minimize the transient response of the aircraft when the store is launched and to effectively reduce the unexpected roll motion that occurs for the pure longitudinal maneuvering in the asymmetric store configuration. As a result of the frequency- and time-domain evaluation, the proposed control method can effectively reduce the transient response for store launch and minimize unexpected roll motion for the pure longitudinal maneuver. Therefore, this control method can effectively improve flying qualities and mission efficiency by reducing the pilot’s workload in the operation of the asymmetric store configuration.
Highlights
Maneuverable fighter aircrafts carry various stores such as missiles, bombs and fuel tanks internally or externally for air-to-air and air-to-ground missions [1]
The degradation of performance, flying qualities, structure and flutter usually occur at the store separation flight test event [2,3]
When additional stores are carried on the aircraft, flight characteristics such as flying qualities and store separation should be verified through flight tests
Summary
Maneuverable fighter aircrafts carry various stores such as missiles, bombs and fuel tanks internally or externally for air-to-air and air-to-ground missions [1]. The T-50 [15,16] advanced supersonic trainer has improved flying qualities of asymmetric store configuration by designing the blend roll control system that increases the control gain of the roll rate feedback, which is in a small range of roll control input and roll rate of the aircraft, to reduce the roll control input required for pure longitudinal axis maneuvering. The EF-2000 [18] and JAS-39 [19] improved flying qualities to reduce the pilot’s maneuvering workload in the asymmetrical store configuration by designing the automatic trim function in all axes These control methods should be premised on securing an accurate mathematical model of the aircraft and a limited method on reducing the transition response for store launch and the rolling motion resulting from the change of AoA and airspeed in the pure longitudinal maneuver. This means that the flying quality parameters in desired dynamics must be adjusted based on the off-line optimization procedure to compensate for uncertainties of aircraft dynamics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
