| 主权项 |
1. A method for providing guidance during a flare maneuver of an aircraft throughout a flare trajectory from a flare engage altitude to a touchdown zone, said method comprising:
utilizing a primary flare command from a primary flare control law based on an altitude of said aircraft that is affected by irregularities in terrain prior to a landing zone threshold, said primary flare command comprises a primary commanded pitch rate of said aircraft resulting from said primary flare command; utilizing a secondary flare command from a secondary flare control law based on only inertial vertical speed of said aircraft that is unaffected by said irregularities in terrain prior to said landing zone threshold, said secondary flare command comprises a secondary commanded pitch rate of said aircraft resulting from said secondary flare command; initially comparing said primary commanded pitch rate and said secondary commanded pitch rate at said flare engage altitude; selecting, at said flare engage altitude, one of:
said primary flare command, when said primary commanded pitch rate is greater than or equal to said secondary commanded pitch rate, andsaid secondary flare command, when said secondary commanded pitch rate is greater than said primary commanded pitch rate; continuously comparing said primary commanded pitch rate and said secondary commanded pitch rate throughout said flare trajectory; and guiding said aircraft along said flare trajectory, from said flare engage altitude to said landing zone threshold, by:
switching selection from said primary flare command to said secondary flare command when said secondary commanded pitch rate becomes greater than said primary commanded pitch rate; andswitching selection from said secondary flare command to said primary flare command when said primary commanded pitch rate becomes greater than or equal to said secondary commanded pitch rate. |
