Energy-Efficient Arrival with RTA Constraint for Multirotor eVTOL in Urban Air Mobility

The electric vertical takeoff and landing (eVTOL) aircraft can alleviate transportation congestion on the ground by using three-dimensional airspace efficiently. However, the endurance of lithium-ion polymer (Li-Po) batteries imposes critical constraints on the operational time span of an eVTOL aircraft on urban air mobility (UAM) passenger transportation mission. This research focuses on the formulation of fixed-final-time multiphase optimal control problem with energy consumption as the performance index for a multirotor eVTOL aircraft. The proposed multiphase optimal control problem formulation and the numerical solution enables a multirotor eVTOL aircraft to meet the assigned required time of arrival and achieve an energy-efficient arrival trajectory for a given concept of operation (CONOP), which is a critical enabler for the safe and efficient future eVTOL operations for passenger transportation and cargo delivery. The problem formulation is applied to a UAM passenger transportation use case with EHang 184 eVTOL aircraft, and an Uber-proposed vertiport for five different types of CONOPs. Finally, the energy consumed for all the CONOPs is compared to propose the most energy-efficient CONOP for a multirotor eVTOL on UAM passenger transportation mission. The proposed framework can also be used to address an energy-efficient cargo delivery application in a UAS traffic management context.