Abstract—Delta Wing aircraft operating at high angles of attack may exhibit a nonlinear oscillatory motion known as the wing rock phenomenon. This instability originates from asymmetric aerodynamic vortices that produce nonlinear rolling moments, making the aircraft difficult to control using the classical linear method. This study presents the design and simulation of an Active Disturbance Rejection Control (ADRC) strategy for the roll dynamics of delta-wing aircraft. The nonlinear aerodynamic effects are treated as a generalized disturbance and estimated using an Extended State Observer (ESO). The estimated disturbance is then compensated in the control law to improve tracking performance and robustness. The classical nonlinear delta wing model used in adaptive control literature is adopted as the plant model. The observer estimates both the plant states and the lumped disturbance. A second-order reference model generates the desired bank angle trajectory, and the ADRC controller forces the plant to track this trajectory. Numerical simulations are conducted in MATLAB to investigate open-loop aircraft behaviour, disturbance estimation accuracy, command tracking performance and control effort. The ADRC controller is compared with a conventional state feedback controller. The result show that ADRC reduced the peak bank angle tracking error from 1.6° to 0.8°, reduced the peak roll rate response from 5.3 deg/s to 4.1 deg/s, decreased the overshoot from 3.75% to 1.5%, and reduced the Integral Absolute Error (IAE) from 1.0889 to 0.5309. These results demonstrated the effectiveness of ADRC for suppressing wing-rock oscillations and compensating for nonlinear aerodynamic disturbances in delta-wing aircraft dynamics.

Keywords—active disturbance rejection control, delta-wing aircraft, wing-rock instability, extended state observer, nonlinear control, disturbance estimation

Cite: Fatima Muhammed Hafth, Ayad AL-Dujaili, and Amjad J. Humaidi, "Active Disturbance Rejection Control for Delta-wing Aircraft," International Journal of Mechanical Engineering and Robotics Research, Vol. 15, No. 5, pp. 542-548, 2026. doi: 10.18178/ijmerr.15.5.542-548

Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).