Short Landing for Flying-Wing Unmanned Aircraft with Thrust Vector

The task of achieving a safe and short landing for a flying-wing unmanned aircraft with a three-bearing-swivel thrust vector is highly challenging. The process is further complicated due to the need to switch between multiple control modes, while also ensuring the protection of the flight boundaries from environmental disturbances and model uncertainties to ensure flight safety. To address this challenge, this paper proposes a short-landing strategy that employs mixed control using lift fans, thrust vectors, and aerodynamic control surfaces. The extended state observer (ESO) is integrated into the inner angular rate control and outer sink rate control to account for environmental disturbances and model uncertainties. To ensure flight safety, the attainable linear and angular acceleration is calculated through a trim analysis to determine the command value of velocity and angle of attack during a short landing. Additionally, a flight boundary protection method is employed which includes an additional command value of the angle of attack, resulting in a higher probability of a successful landing. This paper provides a detailed description of the short-landing strategy, including the control objectives for each phase. Finally, a Monte Carlo simulation is conducted to evaluate the effectiveness and robustness of the short-landing strategy, and the landing accuracy is assessed using the circular error probability metric.

Automated summary

This paper proposes a short-landing strategy for a flying-wing unmanned aircraft using mixed control methods and considering environmental disturbances and model uncertainties. The strategy incorporates lift fans, thrust vectors, and aerodynamic control surfaces for control. Trim analysis is used to determine the command values of velocity and angle of attack for ensuring flight safety, and a flight boundary protection method is employed to increase the probability of successful landing. A Monte Carlo simulation is conducted to evaluate the effectiveness and robustness of the strategy, with landing accuracy assessed using the circular error probability metric.