Tracking control for angular-rate-sensorless vertical take-off and landing aircraft in the presence of angular-position measurement delay

In this study, the authors address the non-linear tracking problem of a roll-rate-sensorless vertical take-off and landing aircraft in the presence of roll-angle measurement delay. By using the first-order Pade?? approximation signal of the delayed roll angle, the authors develop an extended attitude observer and a tracking controller based on the observer, two global coordinate transformations and an extension of backstepping technique. Moreover, a finite-time-convergent differentiator is introduced to simplify the computation of one of the control signals. The resulting approximate tracking controller is practicable for actual implementation. Numerical simulations are performed to show the effectiveness of the approximate controller.