Abstract: A method and apparatus for estimating an airspeed of a rotorcraft by analyzing its rotor. The rotorcraft includes a fuselage and a main rotor that is equipped with a plurality of blades and that rotates about an axis of a hub of the rotor, and in which the free end or “tip” of each blade describes a path in the vicinity of a tip-path plane. The method makes it possible to determine said airspeed of the rotorcraft in a frame of reference united with the tip-path plane by solving a model of the rotor that puts a pitch angle of at least one blade relative to the tip-path plane into relation with the airspeed of the rotorcraft and with an auxiliary speed. The auxiliary speed may be an induced velocity of the air flowing through the rotor or else an axial airspeed at the upstream infinity of the rotorcraft.

Abstract: A system and to a method of analyzing and monitoring interfering movements of an inertial unit of an aircraft during a stage of statically aligning the inertial unit. During the static alignment stage, measurements of the velocity of the aircraft relative to the ground are acquired, and states of a mirror process having a model that is close to the model of the process of aligning the inertial unit are estimated. The states of the mirror process are estimated from observations constituted by the measurements of velocity relative to the ground. Finally, the estimates of the states are compared with respective validation thresholds in order to validate or not validate said alignment of the inertial unit.

Abstract: A device for determining a state of a rotor of a rotorcraft. The rotorcraft comprises a fuselage and a main rotor provided with a hub rotating about a mast of the rotor and with a plurality of blades whose second ends describe a trajectory defining a tip path plane. The device includes a sensor for measuring an angular velocity of a blade about a pitch axis. The device thus makes it possible to determine a state of the rotor, comprising, for example, estimates of a longitudinal cyclic pitch and of a lateral cyclic pitch of the blade with respect to the tip path plane.

Abstract: A system and to a method of analyzing and monitoring interfering movements of an inertial unit of an aircraft during a stage of statically aligning the inertial unit. During the static alignment stage, measurements of the velocity of the aircraft relative to the ground are acquired, and states of a mirror process having a model that is close to the model of the process of aligning the inertial unit are estimated. The states of the mirror process are estimated from observations constituted by the measurements of velocity relative to the ground. Finally, the estimates of the states are compared with respective validation thresholds in order to validate or not validate said alignment of the inertial unit.

Abstract: A system and to a method of analyzing and monitoring interfering movements of an inertial unit of an aircraft during a stage of statically aligning the inertial unit. During the static alignment stage, measurements of the velocity of the aircraft relative to the ground are acquired, and states of a mirror process having a model that is close to the model of the process of aligning the inertial unit are estimated. The states of the mirror process are estimated from observations constituted by the measurements of velocity relative to the ground. Finally, the estimates of the states are compared with respective validation thresholds in order to validate or not validate said alignment of the inertial unit.

Abstract: A method and apparatus for estimating an airspeed of a rotorcraft by analyzing its rotor. The rotorcraft includes a fuselage and a main rotor that is equipped with a plurality of blades and that rotates about an axis of a hub of the rotor, and in which the free end or “tip” of each blade describes a path in the vicinity of a tip-path plane. The method makes it possible to determine said airspeed of the rotorcraft in a frame of reference united with the tip-path plane by solving a model of the rotor that puts a pitch angle of at least one blade relative to the tip-path plane into relation with the airspeed of the rotorcraft and with an auxiliary speed. The auxiliary speed may be an induced velocity of the air flowing through the rotor or else an axial airspeed at the upstream infinity of the rotorcraft.

Abstract: A device of piloting sensors for a rotary wing aircraft having at least two IMU inertial modules, at least two GNSS receivers having respective first fault detection and exclusion modules for detecting and excluding failures and covering distinct GNSS satellite navigation systems, at least two second FDE modules, at least two hybridizing platforms, and at least one third FDE module. The FDE modules enable signals that are of integrity and/or signals that are erroneous to be detected so as to exclude each GNSS system that is defective. In addition, each hybridizing platform makes it possible to determine a hybridized ground speed in order to delivering a ground speed for said aircraft that is accurate and of integrity.

Abstract: A device for estimating an aircraft's speed relative to the ground and heading, while making no use of the rotation of the Earth or of the Earth's magnetic field. The device comprises in particular a first linear estimator that hybridizes a measurement of the speed of the aircraft relative to the ground as provided by a global navigation satellite system (GNSS) receiver with measurements of the acceleration and the attitudes of the aircraft coming from an attitude and heading reference system (AHRS) device without a gyrocompass and without a magnetometer. The first estimator is made linear by replacing the single “heading error estimate ??” state of prior art embodiments with two states, namely estimates of the sine and of the cosine of the heading error.

Abstract: A system and to a method of analyzing and monitoring interfering movements of an inertial unit of an aircraft during a stage of statically aligning the inertial unit. During the static alignment stage, measurements of the velocity of the aircraft relative to the ground are acquired, and states of a mirror process having a model that is close to the model of the process of aligning the inertial unit are estimated. The states of the mirror process are estimated from observations constituted by the measurements of velocity relative to the ground. Finally, the estimates of the states are compared with respective validation thresholds in order to validate or not validate said alignment of the inertial unit.

Abstract: A device for estimating an aircraft's speed relative to the ground and heading, while making no use of the rotation of the Earth or of the Earth's magnetic field. The device comprises in particular a first linear estimator that hybridizes a measurement of the speed of the aircraft relative to the ground as provided by a GNSS receiver with measurements of the acceleration and the attitudes of the aircraft coming from an AHRS device without a gyrocompass and without a magnetometer. The first estimator is made linear by replacing the single “heading error estimate ??” state of prior art embodiments with two states, namely estimates of the sine and of the cosine of the heading error.

Abstract: A device of piloting sensors for a rotary wing aircraft having at least two IMU inertial modules, at least two GNSS receivers having respective first fault detection and exclusion modules for detecting and excluding failures and covering distinct GNSS satellite navigation systems, at least two second FDE modules, at least two hybridizing platforms, and at least one third FDE module. The FDE modules enable signals that are of integrity and/or signals that are erroneous to be detected so as to exclude each GNSS system that is defective. In addition, each hybridizing platform makes it possible to determine a hybridized ground speed in order to delivering a ground speed for said aircraft that is accurate and of integrity.

Abstract: A chained information exchange system (10) comprising a chain of modules (1, 2, 3, 4, 5), each module (1, 2, 3, 4, 5) being connected to one or two other modules (1, 2, 3, 4, 5) via digital buses (11, 12, 13, 14, 15), thereby forming a chain that is open or else a continuous loop that is closed. Each digital bus (11, 12, 13, 14, 15) is a hardened digital bus, capable of withstanding external electromagnetic disturbances, and it is unidirectional. A signal travels in said information exchange system (10) and consequently through each module (1, 2, 3, 4, 5), and after passing through a module (1, 2, 3, 4, 5), said signal contains information that the module (1, 2, 3, 4, 5) through which it has passed does not modify and that is addressed to at least one other module (1, 2, 3, 4, 5), together with specific information that has been added by said module (1, 2, 3, 4, 5) through which it has passed and that is addressed to at least one other module (1, 2, 3, 4, 5).

Abstract: A method and a device (50) for issuing a terrain avoidance warning for a rotary wing aircraft (100) during which at least one bundle (N1, N2) of possible avoidance trajectories for said aircraft (100) is prepared in order to avoid a collision between said aircraft (100) and the relief (70) being overflown. A warning is then triggered as soon as said relief (70) being overflown is found to be at a distance from any one of said bundles (N1, N2) of possible avoidance trajectories that is less than a predetermined distance (Mv). Said avoidance trajectories are determined on the basis of a predetermined avoidance maneuver and on the basis of states of said aircraft (100), said predetermined avoidance maneuver being performed at a predetermined maximum power of said aircraft (100).

Abstract: A method and a device (50) for issuing a terrain avoidance warning for a rotary wing aircraft (100) during which at least one bundle (N1, N2) of possible avoidance trajectories for said aircraft (100) is prepared in order to avoid a collision between said aircraft (100) and the relief (70) being overflown. A warning is then triggered as soon as said relief (70) being overflown is found to be at a distance from any one of said bundles (N1, N2) of possible avoidance trajectories that is less than a predetermined distance (Mv). Said avoidance trajectories are determined on the basis of a predetermined avoidance maneuver and on the basis of states of said aircraft (100), said predetermined avoidance maneuver being performed at a predetermined maximum power of said aircraft (100).

Abstract: The present invention relates to an inertial measurement device secured to a structure of a vehicle for which it is desired to measure speeds and/or accelerations, the device comprising at least one piece of moving equipment in rotation about a stationary axis of rotation Y relative to the structure, said moving equipment including at least two measurement device having respective sensitivity axes X? and Z? that are mutually orthogonal and that lie in a plane perpendicular to the stationary axis of rotation Y, a motor for driving the moving equipment in rotation, device for determining the angular position of the moving equipment, device for responding to the angular position of the moving equipment to determine the projection of the measurements taken in the rotary frame of reference axes X? and Z? by the said at least two measurement device onto a vehicle frame of reference X and Z.

Abstract: A chained information exchange system (10) comprising a chain of modules (1, 2, 3, 4, 5), each module (1, 2, 3, 4, 5) being connected to one or two other modules (1, 2, 3, 4, 5) via digital buses (11, 12, 13, 14, 15), thereby forming a chain that is open or else a continuous loop that is closed. Each digital bus (11, 12, 13, 14, 15) is a hardened digital bus, capable of withstanding external electromagnetic disturbances, and it is unidirectional. A signal travels in said information exchange system (10) and consequently through each module (1, 2, 3, 4, 5), and after passing through a module (1, 2, 3, 4, 5), said signal contains information that the module (1, 2, 3, 4, 5) through which it has passed does not modify and that is addressed to at least one other module (1, 2, 3, 4, 5), together with specific information that has been added by said module (1, 2, 3, 4, 5) through which it has passed and that is addressed to at least one other module (1, 2, 3, 4, 5).

Abstract: A method of determining an angular velocity of an aircraft includes measuring the angular velocity using at least one gyro delivering a measured angular velocity signal affected by stochastic noise; measuring the angular acceleration of the aircraft using at least one accelerometer delivering a signal representing the angular acceleration of the aircraft; and using a filtering complementary in a frequency domain to combine a sum of the measured angular velocity signal and the angular acceleration signal so as to obtain a hybrid estimated angular velocity signal with reduced stochastic noise.

Abstract: The present invention relates to estimating the attitude angles of an aircraft (1). The estimated attitude angles are generated by a device (9) that performs algorithmic integration on inertial measurements indicative of an angular velocity and of a linear acceleration. Horizontal components (34-39) of desired corrections are obtained by a linear combination of two horizontal components (32-33), with cross coefficients between said horizontal axes being continuous variable over time and dependent on the estimated rate of turn. As a result, the estimated attitude angles are stable, and the biases of the gyros continue to be estimated, including during stages during which the aircraft (1) is turning.

Abstract: The present invention relates to an inertial measurement device secured to a structure of a vehicle for which it is desired to measure speeds and/or accelerations, the device comprising at least one piece of moving equipment in rotation about a stationary axis of rotation Y relative to the structure, said moving equipment including at least two measurement means having respective sensitivity axes X? and Z? that are mutually orthogonal and that lie in a plane perpendicular to the stationary axis of rotation Y, a motor for driving the moving equipment in rotation, means for determining the angular position of the moving equipment, means for responding to the angular position of the moving equipment to determine the projection of the measurements taken in the rotary frame of reference axes X? and Z? by the said at least two measurement means onto a vehicle frame of reference X and Z.

Abstract: Method and apparatus for locating an object (2) that is to be located relative to a reference object (1), by electrically generating a locating signal (SL) by modulating a carrier signal with pseudo-noise. The modulation is continuous and of the ultra-wideband (UWB) type. Analysis using a cross-correlation function between said locating signal (SL) and received reflected signals (SRR1, SRR2) serves to segregate waves that have followed a direct path and any interfering waves that have followed indirect paths, so as to be able to deduce therefrom the shortest overall propagation time corresponding to those of said locating waves (OL) that have followed direct paths. The invention applies in particular to a rotary wing aircraft, e.g. a helicopter drone.