Accession Number : AD0091846


Title :   ANALYSIS OF AN AUTOMATIC CONTROL TO PREVENT ROLLING DIVERGENCE


Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON DC


Personal Author(s) : Phillips, William H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/091846.pdf


Report Date : 18 Apr 1956


Pagination or Media Count : 35


Abstract : An analog computer investigation has been made to determine the effectiveness of an automatic control intended to prevent rolling divergence by offsetting the roll coupling terms in the equations of motion. These terms represent yawing and pitching moments applied to the airplane proportional to the prodiicts of annular velocities in roll and pitch and in roll and yaw. The effects of operating the rudder and stabilizer to offset or overcompensate for these roll coupling terms have been studied in maneuvers sirmilating rolls of a fighter airplane. The effects of pilot' S control movements of the rudder and stabilizer, and of time lag in the control, have been briefly investigated. The proposed control was effective in reducing the excursions of an angle of attack and sides lip in the maneuvers studied. Overcoa%ensating for the roll coupling terms was slightly more effective than exactly off-setting them in maneuvers involving unfavorable pilot control coordination, but such overcompensation resulted in a tendency for unstable oscillations when lag was present in the control. The signals proportional to products of angular velocities required as inputs to the control might be obtained by measuring the annular velocities separately and multiplying them. An alternate method using a gyroscopic instrument to measure these products of annular velocities directly is also described.


Descriptors :   *FLIGHT CONTROL SYSTEMS , *STABILIZATION SYSTEMS , *ANALOG COMPUTERS , ROLL , ANGLE OF ATTACK , TIME LAG THEORY , GYROSCOPES , JET FIGHTERS , EQUATIONS OF MOTION


Subject Categories : Flight Control and Instrumentation


Distribution Statement : APPROVED FOR PUBLIC RELEASE