Robust CDO Trajectory Planning under Uncertainties in Weather Prediction

Uncertainties are inherent in aircraft trajectory planning. Trajectories designed under deterministic hypotheses can cause significant performance degradation or constraint violation if the actual situation significantly differs from the assumed conditions. This study proposes computational strategies to plan a robust trajectory in terms of weather prediction, focusing on continuous descent operations. The members of the Global Ensemble Forecast System are used as a set of weather scenarios to reflect the nature of uncertainty in weather prediction along the flight execution. A robust optimal control problem is formalized, which simultaneously considers a set of trajectories for each of the weather scenarios while minimizing the expected value of the overall operational costs. Numerical simulations prove that the generated trajectories are robust for the predicted set of weather scenarios without violating the imposed constraints. Simulations with various cost index settings and preset required time of arrival further show that the proposed robust optimal control can cope with these varying operational settings.