초록 ▼

A control system for maintaining an aircraft within the lateral boundaries of a runway during landing rollout under conditions of combined crosswind and low runway friction is disclosed. An automatic mode of operation is provided wherein the system utilizes an input signal representative of the head

A control system for maintaining an aircraft within the lateral boundaries of a runway during landing rollout under conditions of combined crosswind and low runway friction is disclosed. An automatic mode of operation is provided wherein the system utilizes an input signal representative of the heading of the runway being utilized and signals provided by (or derivable from ) an inertial navigation system to exercise coordinated control of the aircraft rudder, steering and differential braking system. In a semiautomatic mode of operation, signals supplied by the inertial navigation system (or its equipment) are utilized in conjunction with a continuous command signal that is provided by the pilot to indicate the desired aircraft trajectory. An optional provision is included for limiting the aircraft ground velocity slip angle to a range wherein an increase in ground velocity slip angle results in increased lateral corrective force on the aircraft. An additional optional provision modifies operation of the brake-antiskid system employed by the aircraft so as to reduce braking pressure by an amount that substantially optimizes lateral corrective force on the aircraft.

대표청구항 ▼

Ground roll control apparatus for lateral control of an aircraft during execution of the landing rollout sequence on a runway, said aircraft being of the type that includes a rudder system for aerodynamically establishing lateral control, at least one steerable wheel for exerting lateral control and

Ground roll control apparatus for lateral control of an aircraft during execution of the landing rollout sequence on a runway, said aircraft being of the type that includes a rudder system for aerodynamically establishing lateral control, at least one steerable wheel for exerting lateral control and a braking system with left and right differentially operable left and right brakes for providing additional lateral control, said aircraft being equipped with means for supplying signals representative of the current yaw position of said aircraft, the time rate of change of said current yaw position of said aircraft, the current ground velocity slip angle of said aircraft and the velocity of said aircraft relative to the longitudinal and lateral body axis thereof, said ground roll control apparatus comprising: course error computation means for supplying a ground roll course error signal representative of the difference between the current trajectory of said aircraft and a desired trajectory that will maintain said aircraft within the lateral boundaries of said runway; steering controller means for supplying a steering control signal for operating the steerable wheels of said aircraft, said steering controller means including integral control means for supplying a first component of said steering control signal, said integral control means being responsive to said ground roll course error signal, said signal representative of the current ground velocity slip angle of said aircraft and said signal representative of said current yaw position of said aircraft, said steering controller further including proportional control means for supplying a second component of said steering control signal, said proportional control means being responsive to said ground roll course error signal and said signal representative of the time rate of change in said current yaw position of said aircraft, said steering controller means further including means for combining said first and second components of said steering control signal to produce said steering control signal; rudder controller means for supplying a rudder control signal for operating said rudder system of said aircraft, said rudder controller means including integral control means for supplying a first component of said rudder control signal, said integral control means being responsive to said ground roll course error signal, said signal representative of the current ground velocity slip angle of said aircraft and said signal representative of the current yaw position of said aircraft, said rudder controller means further including proportional control means for supplying a second component of said rudder control signal, said proportional control means being responsive to said ground roll course error signal and said signal representative of the time rate of change in said current yaw position of said aircraft, said rudder control means further including means for combining said first and second components of said rudder control signal, said rudder controller means additionally including rudder authority means for receiving said combined first and second components of said rudder control signal and for supplying said rudder control signal, said rudder authority means exhibiting a gain factor that is a function of the ground roll velocity of said aircraft to supply said rudder control signal at a level that causes said rudder system to provide lateral control that dominates the lateral control provided by said steerable wheels and said braking system during a predetermined high speed portion of said landing rollout sequence; and differential brake controller means for supplying a brake control signal for operating said differentially operable left and right brakes of said aircraft, said differential brake controller means being responsive to said ground roll course error signal and said signal representative of the time rate of change in said current yaw position of said aircraft to selectively reduce one of the pilot-initiated left and right brake signals by an amount proportional to a weighted sum of said signal representative of said ground roll course error signal and said signal representative of said time rate of change in said current yaw position of said aircraft.