Incorporating Handling Qualities Assessment into the Design of Compound Rotorcraft
Open Access
- Author:
- Conti, Angelina Maria
- Graduate Program:
- Aerospace Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- March 28, 2018
- Committee Members:
- Dr. Joseph F. Horn, Thesis Advisor/Co-Advisor
- Keywords:
- Flight Controls
Helicopters
Rotorcraft
ADS-33
Flight Handling Qualities - Abstract:
- The next fleet of rotorcraft will need to achieve higher forward flight speeds to meet the demanding requirements of military operation. One potential solution is to offload the main rotor by compounding with a lifting wing and auxiliary propulsion system. Compound rotorcraft also feature additional control effectors (flaperons, elevators, propeller thrust, etc.), which can be used to augment control response of the aircraft. To leverage the benefits of fly-by-wire flight controls and meet flight handling qualities requirements, it is essential that controller design be incorporated early in the development process. Modern handling qualities design standards, such as ADS-33E-PRF, provide specifications that can be implemented in early design phases. Predictive strategies relate signal response characteristics to desired flight handling qualities specifications, and piloted simulation verifies the results for various maneuvers called Mission Task Elements. This thesis incorporates predictive and experimental handling qualities analysis into the design of a future high-speed compound rotorcraft and its fly-by-wire flight control system. The simulated rotorcraft features a compounded wing and pusher propeller to offload the main rotor, various drag clean-ups and larger installed power to reach high forward flight speeds, and a full-authority dynamic inversion controller to optimize handling qualities. This study focuses on the combined effect of controller and design parameter variations on handling qualities. Initial results revealed that the controller command filter parameter impacts the bandwidth of the aircraft, where increasing this parameter generally improved handling qualities for all cyclic pitch deflections. The addition of redundant controls improved handling qualities by relieving control saturation, and trends from variation of flapping hinge offset and wing/tail size were generally unclear. Future research studies should apply alternative predictive and piloted simulation methods in order to identify and verify trends.