Abstract:
The invention relates to a method for managing altitude data of an aircraft in which a main baro-inertial computation loop is used that uses signals originating from an inertial unit and a standard altitude information item supplied by a main air data reference, and at least one standard altitude information item supplied by a secondary baro-inertial deviation loop respectively using signals from said inertial unit of the main loop and a to standard altitude information item originating from the second air data reference, and a baro-inertial altitude deviation, a vertical speed deviation and accelerometric bias deviation visible on the vertical between the main loop and at least one of said secondary baro-inertial loops are computed.
Abstract:
A hybridized system for measuring the attitude of a wearer, the system includes a satellite positioning system; a measurement unit comprising at least one gyrometer; electronics for calculating the attitude information of the wearer from the information originating from the satellite positioning system and the measurement unit. The hybrid system comprises calculation electronics comprising a means for calculating an angular radius of protection, that is to say an angular radius such that the risk that the error between the calculated attitude and the true attitude of the wearer is not included within this radius is less than a given probability, the radius being equal to the sum of two contributions, the first contribution being equal to positioning errors linked to the measurement unit, the second contribution being equal to positioning errors linked to the satellite positioning system.
Abstract:
The invention relates to a method and a device for verifying the integrity of position vector information obtained by at least two satellite geolocation devices, each of the geolocation devices being able to receive a plurality of wireless signals from a plurality of separate satellites, and to use the received wireless signals to compute a position vector of said geolocation device, including position coordinates computed in a predetermined spatial reference at a given moment in time, each of the geolocation devices being independent of the other geolocation devices, the satellites used being able to be different from one geolocation device to the next. The method includes, for at least one considered pair of geolocation devices made up of a first geolocation device (Gm) and a second geolocation device (Gn), computing (34) a deviation statistic between a first position vector computed by the first geolocation device and a second position vector computed by the second geolocation device, and computing (36) an alarm statistical threshold (S(m,n)) based on the deviation statistic and a first predetermined probability (PFA). The method makes it possible to raise a malfunction alarm by using the computed alarm statistical threshold. The invention also makes it possible to compute (44), for at least one geolocation device of each pair of geolocation devices, an integrity radius from the alarm statistical threshold and a second predetermined probability (PND).
Abstract:
A method of calculating a speed of an aircraft, a method for calculating a protection radius, a positioning system and an associated aircraft are disclosed. In one aspect, the method includes obtaining a measured speed of the aircraft and obtaining a measured position of the aircraft, associated with a reliability protection radius related to position. The method also includes calculating, by a correction loop, a corrected speed, wherein the calculation of the corrected speed includes calculating a calculated position by integration of the corrected speed, and correcting the measured speed as a function of a difference between the calculated position and the measured position. The method further comprising calculating a reliability protection radius related to the corrected speed.
Abstract:
Estimating the speed of an aircraft estimates three components of the speed vector (TAS, AOA, SSA) of an aircraft relative to the surrounding air. The static pressure is estimated on the basis of measurements of geographical altitude. A first intermediate variation of a linear combination of the three components of the speed vector of the aircraft relative to the surrounding air is estimated using explicitly the fact that the pressure measured by the static probe is falsified by a known quantity under the effect of the three components of this speed vector of the aircraft relative to the surrounding air. The process then estimates the three components of the speed vector of the aircraft relative to the air by likening the latter to the speed vector of the aircraft relative to an inertial reference frame and by using inertial measurements. The various estimates are fused to provide a final result.
Abstract:
A method of calculating a speed of an aircraft, a method for calculating a protection radius, a positioning system and an associated aircraft are disclosed. In one aspect, the method includes obtaining a measured speed of the aircraft and obtaining a measured position of the aircraft, associated with a reliability protection radius related to position. The method also includes calculating, by a correction loop, a corrected speed, wherein the calculation of the corrected speed includes calculating a calculated position by integration of the corrected speed, and correcting the measured speed as a function of a difference between the calculated position and the measured position. The method further comprising calculating a reliability protection radius related to the corrected speed.
Abstract:
Method of determining at least one radius of protection associated with a respective navigation parameter of a hybrid inertial navigation system by Kalman filtering employing introduction of a position bias into the state model of the Kalman filter representing the uncertainty associated with the reference safe position.
Abstract:
Method of estimation of the speed of an aircraft relative to the surrounding air, in a reference frame tied to the aircraft estimates an estimated static pressure on the basis of measurements of geographical altitude. The process then estimates a first intermediate variation of the speed of the aircraft relative to the surrounding air using explicitly the fact that the pressure measured by the static probe is falsified by a known quantity under the effect of the speed of the aircraft relative to the surrounding air. Finally, temporal integration of the first intermediate variation of the speed of the aircraft relative to the surrounding air provides an estimated speed of the aircraft relative to the surrounding air.
Abstract:
Method of estimation of the speed of an aircraft relative to the surrounding air, in a reference frame tied to the aircraft estimates an estimated static pressure on the basis of measurements of geographical altitude. The process then estimates a first intermediate variation of the speed of the aircraft relative to the surrounding air using explicitly the fact that the pressure measured by the static probe is falsified by a known quantity under the effect of the speed of the aircraft relative to the surrounding air. Finally, temporal integration of the first intermediate variation of the speed of the aircraft relative to the surrounding air provides an estimated speed of the aircraft relative to the surrounding air.
Abstract:
An inertial reference unit includes a first measurement channel that includes a first high-performance inertial measurement unit for measuring specific forces and angular velocities, a first computing unit able to compute pure inertial data based on the measurements of the first measurement unit; a second measurement channel that includes a second inertial measurement unit of performance lower than the first inertial measurement unit for measuring specific forces and angular velocities; a second computing unit able to compute pure inertial data based on the measurements of the second measurement unit; an integrity check function able to implement a method for checking the integrity of the data of the first measurement channel based and the second measurement channel; and a synchronization device for synchronizing the measurements.