AIRCRAFT AUTOMATIC FLIGHT CONTROL SYSTEM

摘要

An automatic flight control system for aircraft providing improved aircraft response to input displacement commands, especially of the generally step input type, in a simple and economical manner; and further providing an improved yet economical control wheel steering capability. An improved automatic pilot electric surface servomotor system is also disclosed. Smooth and consistent roll acceleration limiting to step-like or abrupt roll attitude displacement commands are provided by rate limiting the displacement signal and then passing the limited signal through a simple lag filter having a predetermined time constant. Control wheel steering is available to the pilot by means of a wheel mounted switch which, when actuated, declutches the autopilot servoes, synchronizes the autopilot references during manual maneuvering through the aircraft manual control mechanism and, upon release of the switch re-establishes any preselected vertical path mode and/or establishes a roll attitude hold mode. Operation of CWS switch may be used to override various autopilot limits and upon release of switch maintains the overridden limit attitude; the autopilot automatically re-establishing automatic flight path demand control when the path demand signal equals the attitude limit established by the human pilot during control wheel steering. The autopilot surface servomotor control loop is characterized by an improved apparatus for limiting the torque output thereof by providing current feedback to the servo amplifier.