RESEARCH FLIGHT TEST OF A RETROFIT RECONFIGURABLE FLIGHT CONTROL SYSTEM

摘要

Aircraft reconfigurable control refers to techniques to redistribute control commands to compensate for changes in the system dynamics that can result from battle damage or flight control effector failure. The US Navy has been evaluating the feasibility and potential for a set of Reconfigurable Flight Control Laws (RCLAWS) that are designed to be an add-on module to an existing control system. The retrofit method of implementing a reconfigurable control system could substantially simplify certification requirements for installation on existing production aircraft. This retrofit reconfigurable control technique modifies the pilot stick and rudder commands to help eliminate undesired motion (e.g., axis coupling) that can result from aircraft damage or flight control failure. By comparing sensor data of the aircraft's actual response to model data of the aircraft's desired response, the RCLAWS determine what additions need to be made to the pilot's commands to produce the expected behavior. Simulation analysis has shown that this technique can greatly improve handling qualities for a wide variety of damage and failure cases. A test team at Patuxent River Naval Air Station has completed four test flights aboard instrumented F/A-18C aircraft during 2005 and 2006. Test-unique flight control computers allowed real-time, predetermined control law changes in a controlled, safe manner during these test flights. Both quantitative aircraft flight data and qualitative pilot Cooper-Harper Handling Qualities Ratings have been collected to validate the simulation and analysis and to help determine the feasibility of the retrofit reconfigurable control concept. Analysis of the data indicates a modest but definite improvement within the limited test envelope. Simulation analysis has indicated that the retrofit reconfigurable control laws offer a greater advantage at higher airspeeds, outside of the cleared test envelope.