Dynamic modelling and active disturbance rejection controller design for a morphing wing mechanism

Dynamic modelling and control system design for an in-plane morphing wing structure, which is proposed by NextGen Aeronautics, Inc., are investigated in this paper. The dynamic model of the morphing wing is developed based on Lagrange method from the viewpoint of energy. The in-plane aerodynamic load acting on the leading edge is considered as an uncertain disturbance. The morphing wing is a complex nonlinear multi-input multi-output system with coupling and actuation redundancy. Therefore, control allocation, decoupling and disturbance rejection are required in the control system design. A control allocator is designed based on pseudo inverse method; two active disturbance rejection controllers, which consist of tracking differentiators, nonlinear state error feedback laws and extended state observers, are adopted for the decoupled systems. The correctness of the model is verified by ADAMS simulation. The control system simulation results compared with PID controller show the abilities of disturbance rejection and decoupling. The results indicate that, integrating Lagrange equation, pseudo inverse control allocation and active disturbance rejection control, is an effective way for modelling and control of complex mechanisms.