Robust skyport location and network design for UAM systems under aircraft failures: A column-and-constraint generation approach

Urban air mobility (UAM) system, an advanced aviation transportation system, has the potential to reduce ground traffic congestion and mitigate environmental challenges in the near future. This study presents a decision support system aimed at minimizing both operating and penalty costs to facilitate the successful implementation of UAM systems. The model considers a choice probability of transportation modes and accounts for reasonable decisions under worst-case scenarios involving disruption outcomes for UAM aircraft, thereby enhancing operational feasibility and robustness. The problem is formulated as a two-stage robust optimization that determines skyport locations and network design while considering aircraft failures. To efficiently solve the problem, we propose a solution methodology based on the column and constraint generation (C&CG) algorithm. The algorithm is specifically designed to handle two-stage robust optimization problems and ensure the (near)-optimal solutions. Numerical experiments are conducted to validate the performance of the proposed methodology in terms of effectiveness and efficiency.