A new closed-loop control allocation method is proposed to distribute the force and moment increment commands among multiple actuators at the same time. An innovative feedback configuration for the force and moment in...
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A new closed-loop control allocation method is proposed to distribute the force and moment increment commands among multiple actuators at the same time. An innovative feedback configuration for the force and moment increment produced by the actuators deflections is added into the trajectory and attitude controlloop, respectively. In addition, the trajectory and attitude controllers designed by nonlinear dynamic inversion are used to derive the desired force and moment increment commands. Then, the stability of the closed-loop system is guaranteed theoretically when the actuators are healthy and fail, where there is no a fault detection method to identify the failure. Finally, the proposed method is used to achieve direct force control for decoupling the attitude and flight trajectory in the longitudinal flight. The nonlinear simulation using Canard Rotor/Wing (CRW) aircraft longitudinal model in fixed-wing mode demonstrates that this method can achieve two direct force control modes: pitch pointing and direct lift, whether the actuators are healthy or fail.
This paper discusses the adaptive controlallocation based fault tolerant flight control problem for an overactuated aircraft in the presence of unknown uncertainties and actuator faults. Inspired by the feedback of c...
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This paper discusses the adaptive controlallocation based fault tolerant flight control problem for an overactuated aircraft in the presence of unknown uncertainties and actuator faults. Inspired by the feedback of control moments, an innovative adaptive closed-loop control allocation scheme with an estimator for the uncertainties is designed to tackle the distinct non-monotonic and the coupled nonlinearity caused by actuator failures or faults. Furthermore, since actuator faults will cause difficulty in modeling the aircraft dynamics precisely, an adaptive super twisting sliding mode controller is developed to track the reference trajectory. The convergence of the adaptive closed-loop control allocation and the stability of the fault tolerant flight control system is analyzed. Simulation results indicate the effectiveness and performance of the developed controller.
A closed-loop control allocation method is proposed for a class of aircraft with multiple actuators. Nonlinear dynamic inversion is used to design the baseline attitude controller and derive the desired moment increme...
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A closed-loop control allocation method is proposed for a class of aircraft with multiple actuators. Nonlinear dynamic inversion is used to design the baseline attitude controller and derive the desired moment increment. And a feedback loop for the moment increment produced by the deflections of actuators is added to the angular rate loop, then the error between the desired and actual moment increment is the input of the dynamic controlallocation. Subsequently, the stability of the closed-loop dynamic controlallocation system is analyzed in detail. Especially, the closedloop system stability is also analyzed in the presence of two types of actuator failures： loss of effectiveness and lock-in-place actuator failures, where a fault detection subsystem to identify the actuator failures is absent. Finally, the proposed method is applied to a canard rotor/wing （CRW） aircraft model in fixed-wing mode, which has multiple actuators for flight control. The nonlinear simulation demonstrates that this method can guarantee the stability and tracking performance whether the actuators are healthy or fail.
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