Longitudinal attitude controller design for aircraft landing with disturbance using ADRC/LQR

In this paper, a control method combining Active Disturbance Rejection Control (ADRC) and optimal control is discussed for large aircraft landing attitude control with disturbances, such as turbulence, gusts and modeling errors. On the basis of the extended state observer (ESO) inherited from ADRC, our design exploits the Linear Quadratic Regular (LQR) replacing the original Proportional-Derivation (PD) gains. This technique can effectively solve the adjustment problems of the former channel parameters in ADRC, and can guarantee the unknown disturbance rejection at the same time. Simulation of the B747 longitudinal nonlinear model is represented to test the method. Results show that this method offers satisfying effects. The design proposed in this paper is superior to LQR in terms of disturbance rejection, and has a better performance than ADRC in the aspects of dynamic behavior.