Rapid multi-source thrust control for STOVL propulsion systems

Abstract In hover mode, short take-off and vertical landing (STOVL) aircraft rely entirely on propulsion-generated multi-source thrust for flight control, where rotor inertia severely limits thrust response bandwidth. This paper investigates the dynamic constraints of multi-source thrust modulation in STOVL propulsion systems and identifies a coordinated variable-geometry mechanism that enables rapid thrust response by constraining the low-pressure shaft speed near its nominal value. By dynamically reallocating turbine power through coordinated adjustment of nozzle throat area and lift-fan inlet guide vane, the slow rotor-dynamic effects are suppressed and thrust response is dominated by fast flow dynamics. Based on this mechanism, an offline feedforward schedule is generated using a two-stage nonlinear optimization on a component-level model, enabling decoupled control of total thrust and thrust split under physical constraints. An adaptive incremental model-based controller is further employed to compensate for disturbances and modeling uncertainties. Hardware-in-the-loop simulations demonstrate that the proposed approach achieves approximately a 2.6-fold improvement in closed-loop bandwidth compared with a conventional method.