Technical status and development of electric vertical take-off and landing aircraft

The development of electric Vertical Take-off and Landing (eVTOL) aircraft is greatly promoted for the advances in battery and motor technologies and the application of distributed electric propulsion system. In this paper, the advantages and disadvantages of different eVTOL configurations and their application scenarios are summarized, and a comprehensive comparison between eVTOL and conventional fuel aircraft is made in terms of performance, noise and cost. The interaction noise by rotors and rotor-wing is more prominent for eVTOL, but the electric propulsion rotor system with low tip speed and large rotor solidity greatly reduces its noise level (about a reduction of 15 dB). Lithium-ion batteries are the main energy source for current and future eVTOL. The advanced battery material system, integrated design of battery-structure and excellent battery management system are effective ways to improve the energy density and energy security of the whole aircraft in the future. The redundant manipulation of eVTOL increases the difficulty of flight control system design, but improves the safety of the whole aircraft at the same time. Fault reconstruction and collaborative control are new challenges faced by eVTOL. A wide variety of configurations and novel design features such as high voltage power, electric propulsion, flight-by-wire flight system and electric actuation are proposed for eVTOLs. In the absence of flight test data, the system-based method is the main method for safety design of eVTOL.