ANALYSIS OF AN AUTOMATIC CONTROL TO PREVENT ROLLING DIVERGENCE

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.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Apr 18, 1956
Accession Number
AD0091846

Entities

People

  • William H. Phillips

Organizations

  • National Aeronautics and Space Administration

Tags

DTIC Thesaurus Topics

  • Aeronautical Laboratories
  • Aircrafts
  • Airplanes
  • Analog Computers
  • Angular Momentum
  • Calibration
  • Computers
  • Dynamic Pressure
  • Equations
  • Equations Of Motion
  • Fighter Aircraft
  • Flight
  • Flight Paths
  • Mach Number
  • Measurement
  • Orientation (Direction)
  • Resonant Frequency

Readers

  • Aerodynamics/Aeronautics.
  • Control Systems Engineering.