  It has been considered that urban air mobility (UAM), also known as
drone-taxi or electrical vertical takeoff and landing (eVTOL), will play a key
role in future transportation. By putting UAM into practical future
transportation, several benefits can be realized, i.e., (i) the total travel
time of passengers can be reduced compared to traditional transportation and
(ii) there is no environmental pollution and no special labor costs to operate
the system because electric batteries will be used in UAM system. However,
there are various dynamic and uncertain factors in the flight environment,
i.e., passenger sudden service requests, battery discharge, and collision among
UAMs. Therefore, this paper proposes a novel cooperative MADRL algorithm based
on centralized training and distributed execution (CTDE) concepts for reliable
and efficient passenger delivery in UAM networks. According to the performance
evaluation results, we confirm that the proposed algorithm outperforms other
existing algorithms in terms of the number of serviced passengers increase
(30%) and the waiting time per serviced passenger decrease (26%).
