PilotEd SiMulation Evaluation Of AugmenteD ControL ModeS And Mode ReversionS On An EvtoL Aircraft

Abstract

Control laws were designed for a Lift + Cruise eVTOL aircraft and evaluated in piloted simulation. The control laws feature an Attitude Command baseline control mode and selectable augmented modes intended to achieve Simplified Vehicle Operation. Translation Rate Command / Position Hold (TRC/PH) is used in hover / low speed and a Unified flight control is used in forward flight. The simulation test applied the Simulation based Automation and Failure Evaluations (SAFE) process to evaluate the controller in baseline mode, augmented modes, and fault cases where the control reverts to baseline mode. The test found that the TRC/PH controller provided level 1 handling qualities in a Precision Hover, while degrading to Level 2 with a mode reversion. The SAFE process was able to reveal handling qualities deficiencies in a heliport approach, and the Unified control law was improved for both nominal operation and during mode reversions.