Patent ID: 8812178
Filing Date: 2014-08-19
Classification: B64C,G05D

Abstract:
1. A method for automatic yaw axis control in an aircraft with mechanical flight controls, implemented in an automatic flight control system of the aircraft, said aircraft including a yaw actuator adapted to control the orientation of a yaw control surface, said yaw actuator being also adapted to deliver a measured value of the torque generated on the yaw control surface, a yaw trim actuator adapted to drive movement of a yaw trim control surface for limiting the force to be applied by the yaw actuator to produce the required orientation of the yaw control surface, and a set of sensors for supplying an estimate of a lateral yaw force to which the aircraft is subjected in flight, said method comprising steps of calculating: a setpoint value for the position of the yaw control surface sent to the yaw actuator and determined by means of the estimate of the lateral force, an estimated torque of the yaw actuator determined by means of the measured value of the torque of the yaw actuator and a measured position of the yaw control surface, the estimated torque calculated in this way having a lower oscillation dynamic range than the measured torque, and a trim command for activating and deactivating the yaw trim actuator determined by means of the estimated torque.