V-22 Roll On Deck Control Law Design

Flight control software to enhance V-22 operational effectiveness on and near the ship deck is discussed. Control law design, simulation, and shipboard verification of the enhanced flight control software are discussed. The control law design effort centers around the use of regime recognition, enhanced predictive techniques, and active control technologies to increase lateral control power, enhance control response bandwidth and predictability, and improve disturbance rejection due to ship motion and rotor wake impingement from other aircraft. Incorporation of several features and functions developed under the U. S. Army Helicopter Active Control Technology (HACT) flight control research program into the enhanced V-22 flight control software is discussed. These features include a Rotor Tip-Path Plane Response Type for reduced lateral axis workload and decreased sensitivity to ship motion, actuator rate command prioritization and roll acceleration command model limiting for optimal performance and predictability in response to large amplitude pilot inputs, and torque prediction for optimal allocation of lateral control authority subject to mast torque limits. Simulation predictions, flight test data, and sea trials test results are presented to validate the effectiveness of the control laws in improving handling qualities and flight control precision while mitigating V-22 roll responses to ship deck motion and rotor wake impingement from other aircraft.