Method of controlling the yawing movement of an aircraft running along the ground
A method of controlling a yawing movement of an aircraft running along the ground, the aircraft comprising at least one first landing gear with a steerable bottom part bearing wheels. The method comprises the steps of (1) on the basis of a yaw rate setpoint {dot over (φ)} c , determining a wheel-steering prepositioning angle θ p ; and (2) using closed-loop control which as its input has the yaw rate setpoint and which generates a command to steer the bottom part in order to steer it through a steering angle θ c equal to the sum of this prepositioning angle θ p and of an angle θ z which is determined taking account of an error between the yaw rate setpoint {dot over (φ)} c and the measured yaw rate {dot over (φ)} m when the steerable bottom part is steered by the steering angle θ c .
1. A method of controlling a yawing movement of an aircraft having a fuselage and running along the ground, the aircraft comprising at least one first landing gear with a steerable bottom part bearing wheels, the method being characterized in that it comprises the steps of:
on the basis of a yaw rate, determining a wheel-steering prepositioning angle θ p ;
using closed-loop control, which as its input has the yaw rate and which generates a command to steer the steerable bottom part in order to steer the steerable bottom part through a required steering angle θ c equal to the sum of said prepositioning angle θ p and an angle θ z , which is determined by taking account of an error, between the yaw rate and a measured yaw rate φ m , when the steerable bottom part is steered by the required steering angle θ c ;
the method applied to an aircraft further comprising at least two main landing gears with wheels and being positioned, respectively, a left main landing gear on a left side of the fuselage and a right main landing gear on a right side of the fuselage and the wheels each of said left and fight main landing gears being associated with torque application members, the method further comprising the step of generating, for attention of the torque application members of the left and fight main landing gears, two acceleration setpoints, a left setpoint {acute over (Γ)} g and a right setpoint {acute over (Γ)} d , so that the torque application members thus stimulated generate, on the aircraft, a yaw moment M zp that complements the yaw moment M za generated by the first landing gear, so that the total yaw moment generated on the aircraft allows the aircraft to comply with the yaw setpoint φ c ; and
the method in which the acceleration setpoints {acute over (Γ)} g , {acute over (Γ)} d are generated taking account of saturations in the accelerations on the right side (Sat g ) and on the left side (Sat d ) of the wheels of the right and left main landing gears, respectively.
2. The method according to claim 1 , in which the required steering angle θ, is equal to a sum of the prepositioning angle θ p and the angle θ z , which is further determined taking account of an error between the required steering angle θ c and a measured steering angle θ m .
3. The method according to claim 1 , in which the acceleration setpoints {acute over (Γ)} g , {acute over (Γ)} d are generated taking account of an error between the yaw rate setpoint φ c and the measured yaw rate φ m .
4. The method according to claim 3 , in which the acceleration setpoints Γ g , Γ d are generated taking further account of an error between a rotation differential setpoint Δω c that is the differential in rotation between the wheels of the left and right main landing gears and a measured rotation differential Δω m that is the differential in rotation between the wheels of the right and left main landing gears.