Modelling and simulation of inclined vertical landing for an F-35B-type aircraft

Abstract

This research presents a control-oriented nonlinear mathematical model and control framework for the short take-off and vertical landing (STOVL) dynamics of an F-35B aircraft, specifically focusing on the critical phase of an inclined landing trajectory. The aircraft is characterised as a six-degree-of-freedom (6-DOF) rigid body within the North-East-Down (NED) inertial frame, explicitly incorporating cross-coupling effects in the inertia tensor. The integrated modelling architecture encompasses a multi-nozzle propulsion system comprising a lift fan, a rear swivel nozzle with thrust vectoring capabilities, and dual-wing roll posts and a control-oriented aerodynamic model based on stability derivatives and dynamic pressure scaling. A significant contribution of this study is the extension of the rigid-body equations with a three-point landing gear subsystem that accounts for independent unsprung masses, linear suspension compliance and unilateral tire contact constraints, enabling a realistic simulation of the transition from jet-borne flight-to-ground interaction. To stabilise the inherently unstable STOVL envelope, a linear quadratic regulator (LQR) is synthesised via numerical linearisation of the nonlinear plant. Simulation results demonstrate the controller’s effectiveness in maintaining precise trajectory tracking and attitude regulation, successfully managing the complex force interactions between the propulsion system and the mechanical suspension during touchdown on a landing surface.