Patent ID: 7555371

Claim:
Automatic piloting device for rotary wing aircraft comprising: means for preprocessing measurements of attitude, of roll pitch and yaw rotation rates, of accelerations and of ground speed provided by an inertial platform affected by drifting and noisy measurements of longitudinal and lateral components of the ground speed of the aircraft that are provided by a readjustment device exhibiting periods of unavailability, and means for formulation formulating piloting orders or directives by applying flight control laws to the instantaneous conditions of flight corresponding to the preprocessed information delivered by the preprocessing means; said preprocessing means comprising at least one second-order complementary type estimator filter comprising two additive branches: a first branch, with positive nominal inherent gain K 1 comprising an integration stage, estimating a contribution to the readjustment of a speed bias and eliminating the noise of the signals of the readjustment device and a second branch, with positive nominal gain formed from the product of the inherent gain K1 of the first branch and of an inherent gain K2, comprising two successive integration stages and estimating the contribution to the readjustment of an acceleration bias; wherein said inherent gains K1, K2 are zeroed during the periods of unavailability of the readjustment device.