Abstract
Centre-of-gravity (c.g.) of combat aircraft suffers significant lateral deviation due to asymmetric release of stores, leading to a highly nonlinear and coupled dynamics. Additional nonlinearity and coupling result when the aircraft attempts some supermanoeuvres under such conditions rendering nonlinear control implementation unavoidable. However, such controls depend on accurate onboard c.g information. The present paper proposes a novel neural network aided sliding mode based hybrid control scheme which does not require such an information. The neural controller is trained offline to compensate for the changed dynamics arising from the lateral mass asymmetry, while the sliding controller is designed for the intended manoeuvres under the nominal situation. Cobra and Herbst manoeuvres are simulated for various lateral c.g. movements to validate the scheme.
Highlights
Aircraft having lateral asymmetry in inertial and aerodynamic properties inherent in their structure have recently gained prominence in aircraft flight dynamics and control research [1,2,3,4,5,6,7,8,9]
The present paper attempts to remove such restrictions on online c.g. information, as well as increased computation power requirement altogether so that a fixed parameter control scheme can effectively handle a wide range of asymmetric c.g. variations resulting from arbitrarily asymmetric release of stores
A sliding controller is designed for the symmetric aircraft using the standard symmetric six degree of freedom (6-DOF) dynamics for the faster inner loop involving angular rates. This inner loop controller is aided by a Multilayer Feedforward Neural Network (MFNN) controller to take care of the changes in the dynamics arising from the lateral c.g. shift
Summary
Aircraft having lateral asymmetry in inertial and aerodynamic properties inherent in their structure have recently gained prominence in aircraft flight dynamics and control research [1,2,3,4,5,6,7,8,9]. During the standard fighter aircraft manoeuvres, the aircraft is usually required to pitch up to a very high angle forcing it to operate in the high angle of attack regions, i.e. regions far exceeding the stall limit In such regions, the aircraft flight dynamics becomes predominantly nonlinear due to aerodynamic, inertial and trigonometric effects [10]. A sliding controller (denoted as the Nominal SMC) is designed for the symmetric aircraft (or the nominal aircraft) using the standard symmetric six degree of freedom (6-DOF) dynamics for the faster inner loop involving angular rates This inner loop controller is aided by a Multilayer Feedforward Neural Network (MFNN) controller (as shown in Fig. 1) to take care of the changes in the dynamics arising from the lateral c.g. shift.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
