Performance analysis of nonlinear observers applied to the fixed-wing unmanned aerial vehicles flight under decoupled-reduced model

Abstract

In this paper, we present the design and implementation of two nonlinear observers: nonlinear extended state observer and sliding mode observer for estimating the pitch, yaw and roll angles and angular rates of a fixed-wing unmanned aerial vehicles system under a decoupled-reduced model in real flight experiments. A backstepping control law is designed for control in a decentralized way for altitude, yaw and roll of the airplane. This scheme allows us to test experimentally the feasibility of using the online estimated data from the observers in flight control, which is useful for increasing the robustness of the control and the safety of flight. Furthermore, a comparative analysis of the performance of both nonlinear observers is conducted.

Fixed-Wing MAV Adaptive PD Control Based on a Modified MIT Rule with Sliding-Mode Control

“…Remark 1 It should be mentioned that the mathematical model defined in this work, only represents the Euler angles and the angular rates, due to that with this approximation in the mathematical model has been obtained a good performance in real-time flight tests (see [12,13], and [14]).…”

“…The validation of the model has been proved with the design of the backstepping controller presented in [12] and with the design of nonlinear observers presented on [13], that is, the backstepping controller needs the complete knowledge of the model for its design process and the same situation can be consider for the design of the nonlinear observers (see [13]), otherwise it is not possible to obtain a stable flight with the fixed-wing MAV, namely, it is not possible to achieve the control objective. Therefore, in this sense, we can prove the validity of the aerodynamic model.…”

MRAS Using Lyapunov Theory with Sliding Modes for a Fixed-Wing MAV

“…Remark 1. The mathematical uncoupled model represents the Euler angles and the angular rates because in real-time flight tests it is possible to achieve the desired attitude and altitude of the fixed-wing MAV (see [26][27][28]). To develop the adaptive controller presented in this work requires knowledge of such physical variables.…”

Robust output feedback control of fixed-wing aircraft

“…Owing to the highly nonlinear and complex mathematical model of an aircraft, the state estimation using the state observers remains a challenging task for the researchers. Most of the control and observer design techniques for the aircraft have been developed using the decoupled model which considers the independent lateral and longitudinal models (Andrade and Campos, 2017;Parada et al, 2017). Therefore, the state estimation for a full nonlinear model still needs attention.…”