Research on the Model-Based Analysis of eVTOL UML-2 Functional Requirements and Performance Requirements

Urban air mobility (UAM) technologies are developed quickly and targeted for intercity and intracity passenger-/cargo-carrying operations, among which the electric vertical take-off and landing (eVTOL) aircraft are thought to be key for UAM. Due to the flexibility brought by distributive electric propulsion, the eVTOL aircraft are difficult to operate without sufficient augmented control. For lack of eVTOL operation regulations under novel automation levels, the functional requirements and performance requirements capture and validation are fundamental for eVTOL flight control system design. In this paper, it is assumed that the pilot has final authority and responsibility for the operation and safety of the flight, with an enhanced automatic flight control system (AFCS) available, classified as UML-2 according to NASA. To develop a certifiable UML-2 eVTOL, the top-level requirements of the eVTOL AFCS are captured by use case diagram of model-based system engineering method. Thereafter, a subset of UML-2 functional requirements of eVTOL AFCS in nominal use case is captured, and performance requirement of function “Active avoidance in hover” is validated by visual simulation. The results validate the performance requirement of the example function, providing tool chain solutions for requirement analysis of certifiable eVTOL AFCS.