Thales

Jacques Coatantiec

Christian Mehlen

Nicolas Martin

Marc Revol

Jacques Mandle

Nicolas Vercier

Alain Bibaut

Bertrand Lesot

Patrice Guillard

Pierre-Yves Dumas

Dominique Bouard

Pierre-Jérôme Clemenceau

Sébastien Juillaguet

Roland Bonel

Sebastien Francois Philippe Legoll

Florence De Grancey

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

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.

Hybrid AHRS system comprising a device for measuring the integrity of the calculated attitude

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.

Method for calculating a speed of an aircraft, method for calculating a protection radius, positioning system and associated aircraft

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 (G) and a second geolocation device (G), computing () 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 () an alarm statistical threshold (S(m,n)) based on the deviation statistic and a first predetermined probability (P). 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 (), 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 (P).

Method and integrity verification device location information obtained by at least two satellite geolocation devices

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.

Method of estimation of the speed of an aircraft relative to the surrounding air, and associated 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.

Method of determining a radius of protection associated with a navigation parameter of a hybrid inertial navigation system, and associated system

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.

Hybrid system () comprising an elementary hybrid system () comprising an extended processing module CALC () determining a first protection radius of the hybrid system RHG, associated with a position quantity G, using a first extended variance/covariance matrix MHYPEas a function of a predetermined first false alarm probability PFA, of a predetermined non-integrity level PNI and of a predetermined first probability PPof occurrence of an undetected hardware failure of a satellite positioning receiver.

Hybrid system and device for calculating a position and for monitoring its integrity

Method for determining navigation parameters of an aircraft, characterized in that it consists at least in determining the geographic speed {right arrow over (V)}, expressed in a given local fixed coordinate system {{right arrow over (i)}, {right arrow over (j)}, {right arrow over (k)}}, based on the measurements m, of carrier phase increments &#x394;&#x3c6;of the radio navigation signals originating from a plurality of radio navigation satellites in sight of said aircraft, each of said measurements mconstituting an estimate of the relative speed of said aircraft relative to said satellite projected onto the sight axis linking the aircraft to the satellite, each of said measurements m, being compensated by the apparent radial speed of the satellite.

Method and system for determining navigation parameters of an aircraft

An inertial system measures the attitude of an aircraft consisting at least in determining the angle of pitch and/or the angle of heading and/or the angle of roll of the aircraft, each of the said angles of attitude being determined by successive double integration of their second derivative. A pair of accelerometers to determine the angle of pitch being are disposed on either side of the centre of gravity along an axis substantially merged with the longitudinal axis of the aircraft. A pair of accelerometers to determine the angle of heading are disposed on either side of the centre of gravity along an axis substantially merged with the transverse axis of the aircraft. A pair of accelerometers to determine the angle of roll are disposed on either side of the centre of gravity along a vertical axis perpendicular to the plane formed by the other axes.

Method and system for determining the attitude of an aircraft by multi-axis accelerometric measurements

A method for determining the position of a mobile body at a given instant and for monitoring the integrity of the position of said mobile body includes a step of determining a sustained position at the given instant by adding the integral of the hybrid speed between the preceding instant and the given instant to the position of the mobile body at the preceding instant; a step of determining the sustained protection radius associated with the sustained position by adding the integral of the hybrid speed protection radius between the preceding instant and the given instant to the position protection radius of the preceding instant; a step of determining a better position at the given instant, the better position being: when information from the first positioning device is available, the position associated with a better protection radius, the better protection radius being selected by comparing the intermediate protection radius with the sustained protection radius according to a predetermined selection criterion; and, when information from the intermediate positioning device is unavailable, the sustained position.

Method for determining the position of a mobile body at a given instant and for monitoring the integrity of the position of said mobile body

The invention relates to a navigation system for aircraft comprising inertial sensors, a GNSS receiver and potentially a baro-altimeter. The measurements from the inertial sensors are hybridized with the code and phase measurements from the receiver within a main Kalman filter and, possibly, secondary filters. The said measurements are corrected for several types of errors, notably those due to the passage of the satellite signals through the ionospheric layers. The precision of the determination of the position of the aircraft is greatly improved, both in the horizontal plane and in the vertical direction. This is also the case for the corresponding protection radii, which allows margins to be created in order to satisfy the integrity constraints for the navigation solution.

Navigation system using hybridization by phase measurements

The invention pertains to the monitoring of the integrity of position and speed information arising from a hybridization between an inertial reference system and a satellite-based positioning receiver. The invention relates more precisely to a navigation apparatus known in the art by the name INS/GNSS system (for 'Inertial Navigation System' and 'Global Navigation Satellite System') hybridized in closed loop.

Hybrid INS/GNSS system with integrity monitoring and method for integrity monitoring

The invention relates to a closed loop hybridizing device comprising a Kalman filter bank, a virtual platform, a device to calculate pseudo-measurements estimated a priori. The Kalman filter bank comprises a principal Kalman filter adapted to the calculation of corrections to be applied to inertial measurements starting from all available pseudo-measurements, and n secondary Kalman filters adapted to the calculation of corrections to be applied to inertial measurements from a sub-set of available pseudo-measurements. The corrections originate from either the principal Kalman filter when no pseudo-measurement is erroneous or the secondary Kalman filter not affected by an erroneous pseudo-measurement. The corrections are applied simultaneously to inertial measurements and to the input to all other Kalman filters in the Kalman filter bank. In particular, the invention applies to a hybridizing device using information provided by an inertial unit and a satellite navigation system, for example a GPS system.

Closed loop hybridising device with monitoring of the measurement integrity

The device is for monitoring the integrity of the position and speed information supplied by a hybrid system comprising an inertial unit INS readjusted using a GNSS satellite positioning receiver by means of a Kalman hybridization filter using a readjustment gain K and an evolution matrix F. It includes a satellite problem-detector circuit comprising a bank of predictor/estimator filters which uses the gain K and the evolution matrix F of the Kalman hybridization filter, each filter observing the deviation between the positioning point obtained from the N visible satellites, in the form of geographic coordinates, delivered by the GNSS receiver and one of the positioning points P, also in the form of geographic coordinates, delivered by this same GNSS receiver, obtained by using N&#x2212;1 of the N visible satellites for resolution, and test circuits comparing the states of the predictor/estimator filters with their variances and detecting a satellite failure when a test is positive, the deviation found being greater than a detection threshold.

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Fauconnieres, France

Jacques Coatantiec