Biomechanically Induced and Controller Coupled Oscillations Experienced on the F-16XL Aircraft During Rolling Maneuvers
Smith, John W. and Montgomery, Terry (1996) Biomechanically Induced and Controller Coupled Oscillations Experienced on the F-16XL Aircraft During Rolling Maneuvers. Technical Report NASA TM-4752, Research Engineering, NASA Dryden Flight Research Center.
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Abstract
During rapid rolling maneuvers, the F-16 XL aircraft exhibits a 2.5 Hz lightly damped roll oscillation, perceived and described as “roll ratcheting.” This phenomenon is common with fly-by-wire control systems, particularly when primary control is derived through a pedestal-mounted sidearm controller. Analytical studies have been conducted to model the nature of the integrated control characteristics. The analytical results complement the flight observations. A three-degree-of-freedom linearized set of aerodynamic matrices was assembled to simulate the aircraft plant. The lateral–directional control system was modeled as a linear system. A combination of two second-order transfer functions was derived to couple the lateral acceleration feedthrough effect of the operator’s arm and controller to the roll stick force input. From the combined systems, open-loop frequency responses and a time history were derived, describing and predicting an analogous in-flight situation. This report describes the primary control, aircraft angular rate, and position time responses of the F-16 XL-2 aircraft during subsonic and high-dynamic-pressure rolling maneuvers. The analytical description of the pilot’s arm and controller can be applied to other aircraft or simulations to assess roll ratcheting susceptibility.
| EPrint Type: | NASA Technical Memorandum |
|---|---|
| Keywords: | Biomechanics, F-16XL airplane, Flying qualities, Handling qualities, Human factors, Pilot induced oscillations, Roll control, Roll ratcheting |
| Subjects: | (01 - 09) Aeronautics: (08) Aircraft Stability And Control Aircraft/Project: F-16XL |
| ID Code: | 179 |
| Deposited On: | 08 July 2004 |
| Additional Information: | 38 pages. |
