Thales

Nicolas Vercier

Jacques Coatantiec

Nicolas Martin

Bertrand Leverrier

Bernard Chaumet

Dominique Bouard

A method for calibrating the stiffness mismatch ΔK or quadrature Kxy of a vibrating angular sensor includes a resonator extending about two axes x and y defining a sensor frame xy, comprising a vibrating proof mass comprising two parts configured to vibrate in phase opposition; and detection, excitation, quadrature compensation and stiffness adjustment transducers; and a stiffness matrix Kin the wave frame; the method comprising steps of: A determining the electrical angle; B recovering a quadrature or stiffness term of the stiffness matrix Kin the wave frame, the term being a sum of functions in cos(iθ) and sin(iθ); C determining the amplitudes of the functions in cos(iθ) and sin(iθ); then D determining the stiffness mismatch ΔK or the quadrature Kxy, on the basis of the amplitudes.

Method for calibrating the difference in stiffness and/or quadrature of a vibrating inertial sensor

A method for calibrating an inertial angular sensor includes: for at least two electrical angles of the vibration wave, applying, via each of the three trim controls, a sinusoidal stiffness disturbance having a disturbance frequency, and for each applied disturbance, determining and storing an estimated excitation force to be applied to the resonator in the presence of the stiffness disturbance, on the basis of excitation controls determined by the servo controls; determining, on the basis of the three estimated excitation forces, three 2×2 matrices, being representative of the response of the gyrometer to the stiffness disturbance; determining and storing an estimated inverse excitation matrix and an estimated inverse detection matrix on the basis of the three matrices, an excitation matrix and a detection matrix being respectively representative of effects of the excitation chain and of effect of the detection chain of the sensor.

Method for calibrating a vibrating inertial sensor

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.

Inertial reference unit and system with enhanced integrity and associated integrity-checking methods

The invention proposes a system for excluding a failure of a satellite suitable for a hybrid navigation system and which operates even in case of degraded geometry of the constellation of satellites. The hybrid system according to the invention comprises a plurality M of hybridization filters (SFH, . . . SFH) each receiving at least one satellite positioning measurement (MPS) carried out on the signals received from all the satellites in visibility of the said system and an inertial positioning measurement (MPI) and delivering a corrected positioning measurement, the so-called hybrid measurement (MH, . . . MH), the hybridization filters being updated, at a constant temporal rate, successively at periodically shifted temporal instants.

System for excluding a failure of a satellite in a GNSS system

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.

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Valence, France

Nicolas Vercier