Theoretical Method of Determining the Control Gearing and Time Lag Necessary for a Specified Damping of an Aircraft Equipped with a Constant-Time- Lag Autopilot

摘要

A method is presented for determining the control gearing and time lag necessary for a specified damping of the motions of an aircraft equipped with an autopilot having constant-time-lag characteristics. The method is applied to a typical present-day airplane equipped with an autopilot which applies rudder control proportional to the yawing angular acceleration. The types of motion predicted for this airplane-autopilot system by this method are in very good agreement with the airplane motions calculated by a step-by-step procedure. For some values of control gearing there may exist more than one range of time lag for which the motions of the assumed aircraft- autopilot system will have more than a specified amount of damping.