| Title: |
Lift Rotor Control Power Assessment of a Lift+Cruise Configuration |
| Authors: |
Bossinger, Robert L; Hoffler, Keith D; Adaptive Aerospace Group, Inc |
| Contributors: |
United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center |
| Publisher Information: |
United States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical Center |
| Subject Terms: |
Control systems; VTOL aircraft; Flight control systems; Certification; Rotors; Failure; Fly-by-wire; Prioritization; Rotor failure; Unified Flight Controls |
| Subject Geographic: |
United States |
| Description: |
The recent advent of electric propulsion has freed designers to put propulsors in nonconventional locations and opened aircraft design space to novel configurations. Many electric Vertical Take-off and Landing (eVTOL) aircraft with multiple lift-rotors that require advanced control systems to manage the large number of control effectors are being presented to the FAA for certification. These aircraft generally have nonconventional fly-by-wire flight controls. Extensive understanding of the aircraft and their control effectors, their interactions, and how their use by the control system employs them is required to achieve desired aircraft response and ensure safety. Simultaneous commands to multiple axes can originate from pilot input or the flight controls even if the pilot is only commanding one axis. An understanding of the cross coupling of commands and available control power is needed. This report presents a methodology for assessing control power limitations and results from a limited application of the corresponding method to a representative multi-rotor vehicle. Some of the results emphasize the need for an extensive evaluation. One case shows that defeating envelope protection can occur due to lack of control power in an axis different from the one being commanded. Another case gives an example of a departure from controlled flight when control power priority was applied to the wrong axis for the situation. Specific and general lessons learned are presented and potential application of this method for aircraft evaluation is discussed. |
| Document Type: |
other/unknown material |
| File Description: |
PDF |
| Language: |
English |
| Relation: |
https://rosap.ntl.bts.gov/view/dot/72735 |
| Availability: |
https://rosap.ntl.bts.gov/view/dot/72735 |
| Accession Number: |
edsbas.E89B6852 |
| Database: |
BASE |