A PILOTED MOTION SIMULATOR INVESTIGATION OF VTOL HEIGHT-CONTROL REQUIREMENTS

摘要

A moving-cockpit piloted simulator was used to investigate VTOL aircraft height control requirements during hover. Pilot opinion ratings were used to determine the relationships of control power, damping, and time constant in realistic VTOL hovering tasks. The minimum upward acceleration for "normal operation" was found to be 1.06g while minimum acceptable safe operation was determined to be between 1.02g and 1.03g. Minimum damping levels for normal operation were dependent on control system time constant when operating with high thrust-to-weight ratios. Acceptable control of altitude could be maintained in the event of artificial vertical damper failure as long as the control system time constant remained below 0.37 second. Minimum acceptable control power was found to depend on the vertical velocity response during lift-off and touchdown maneuvers. Hovering steadiness tests with zero velocity damping indicated a tendency to overcontrol at time constants above 0.6 second while the pilot's full attention was required at 1.2 seconds. The relative importance of cockpit motion and visual display in correlating simulator and flight data was briefly investigated.