Using the Task-Pilot-Vehicle (TPV) Approach to Investigate Envelope Protection Design for eVTOL Aircraft

Pilot models have been successfully utilized for design and analysis of rotorcraft for decades. These models are commonly used as analysis tools, usually coupled to flight dynamics models. A method that has been developed is the Task-Pilot-Vehicle (TPV) approach, which utilizes the pilot model in a specific task. This paper presents results from the application of the TPV approach to investigate envelope protection (EP) methods. Four EP methods were chosen for these studies, i) Control Limiting, ii) Command Limiting, iii) MPC Based, iv) Virtual Control Limiting. These methods are exercised with pilot models inside a specifically designed toolbox across several different vehicles, including representative Tiltwing and Quadrotor vehicles, and Handling Qualities Task Elements (HQTEs). Results show that each envelope protection method has advantages and disadvantages, ranging from ease of implementation to potential adverse interactions with the pilot-vehicle system. Overall, the TPV approach shows promise as a method to investigate EP methods for eVTOL/VTOL aircraft.