String stable platoons of all-electric aircraft with operating costs and airspace complexity trade-off
This work addresses the challenge of enabling sustainable and autonomous air traffic procedures for emerging technologies like advanced/urban air mobility, though it is incremental in applying existing control frameworks to a new domain.
The paper tackled the problem of optimizing cruise airspeeds for all-electric aircraft platoons to balance operational costs and airspace complexity, resulting in a suboptimal solution that closely approximates the optimal, ensures safe separations, maintains string stability, and reduces both costs and complexity.
This paper formulates an optimal control framework for computing cruise airspeeds in predecessor-follower platoons of all-electric aircraft that balance operational cost and airspace complexity. To quantify controller workload and coordination effort, a novel pairwise dynamic workload (PDW) function is developed. Within this framework, the optimal airspeed solution is derived for all-electric aircraft under longitudinal wind disturbances. Moreover, an analytical suboptimal solution for heterogeneous platoons with nonlinear aircraft dynamics is determined, for which a general sufficient condition for string stability is formally established. The methodology is validated through case studies of all-electric aircraft operating in air corridors that are suitable for low-altitude advanced/urban air mobility (AAM/UAM) applications. Results show that the suboptimal solution closely approximates the optimal, while ensuring safe separations, maintaining string stability, and reducing operational cost and airspace complexity. These findings support the development of sustainable and more autonomous air traffic procedures that will enable the implementation of emerging air transportation technologies, such as AAM/UAM, and their integration to the air traffic system environment.