Thales

Sextant Avionique

Thales Avionics S.a.

Jean-Louis Lescourret

Siegfried Rouzes

Thomas Espaignet

Serge Ediar

Lilian Lacoste

Pierre Raybaut

The present invention concerns a system for contactless determination of the position and orientation of a first mobile object (M) relative to a reference mark (R) carried by a second fixed or mobile object (P), in a disturbed electromagnetic environment comprising a transmitting antenna (E) with ferromagnetic cores (E-) having magnetic permeability higher than 10, incorporating sensors (E-) for measuring the magnetic field Xactually emitted by the axes of the ferromagnetic cores. A means (-) for extracting the signal correlated with the ambient noise X(T&#x2212;KT)&#x2014;from the sensors (Sb) fixed in the platform (P), forms, with measurement Xof the emitted magnetic induction, a complete model of the measured fields, making it possible to extract, without errors, the six parameters relative to the field model without disturbances.

Hybrid inertial/magnetic system for determining the position and orientation of a mobile body

The present invention relates to a device for optically detecting position and/or attitude of an object () moving in a given travel range (), said device comprising electro-optical sensors positioned on said object and distributed in groups, called clusters (), analysis and computation means () making it possible to find the position and/or the attitude of said object, electronic image generation means () and optical projection means () comprising a display and a projection optic. The optical projection means emit, in a projection cone, a clear image () at any point of the travel range, the analysis of the signals received by the sensors of at least one cluster making it possible to identify the position and/or the attitude of the object in the frame of reference defined by the projection means, the latter consisting of a plane perpendicular to the projection axis, called image plane, and the projection axis.

Device for optically detecting position and/or orientation of objects and associated detection methods

A method and device for magnetic measurement of the position and orientation of a mobile object relative to a fixed structure. The device comprises, Integral with the structure, a magnetic fields emitter assembly having three orthogonal emission coils defining a reference frame and a sensor assembly, integral with the mobile object, having three channels for measuring the field received on three orthogonal detection coils, these channels each incorporating a feedback loop providing an output voltage and a measurement current. A calibration voltage, at frequencies differing from the useful frequencies of the fields, is injected into the channels of the sensor without disturbing the continuous measurement by measurement acquisition channels, while a calibration current is superimposed on the measurement resistors. It is thus possible to identify the variable components of the system and correct the measurements through the inverse of the respective transfer functions of the channels of the sensor.

Method and device for magnetic measurement of the position and orientation of a mobile object relative to a fixed structure

The invention relates to light boxes comprising fluorescent tubes, which are used to illuminate display screens with optical valves, in particular liquid-crystal matrix screens. More specifically, the invention is suitable for use in the field of head-up or medium-head collimated displays used on aircraft. The invention consists in improving the photometric properties of said light boxes using a novel fluorescent tube arrangement, whereby said tubes are distributed over several stacked layers. In this way, the number of fluorescent tubes present in the light box is increased and acceptable heating is maintained. The photometric performances of the light box are thus increased while the correct service life of the tubes is retained.

High-luminance light box for displays

A device for measuring magnetic field(s). The device includes at least one measurement acquisition pathway including a measurement current generator, a coil, a measurement resistor, at least one amplifier, and at least one antialiasing filter, delivering a measurement voltage. The device for measuring magnetic field(s) includes a device for determinating at least one electrical quantity representative of the acquisition pathway. The device for determining includes a mechanism for injecting a predetermined calibration current, including at least two frequency terms at at least two frequencies distinct from those of a measurement current, the calibration current being superimposed on the measurement current. The device for measuring magnetic field(s) also includes a calculation device delivering an estimate of the at least one electrical quantity at the frequency or frequencies of the measurement current.

Device and method for measuring magnetic field(s) with calibration superimposed on the measurement and corresponding uses

The invention relates to a device for measuring the position and the orientation of a mobile object with respect to a fixed structure, in a disturbed magnetic environment, of the type comprising:&mdash;a first assembly of orthogonal coils ( to ) for emitting magnetic field(s), secured to the fixed structure, defining a reference frame;&mdash;a second assembly of orthogonal coils for receiving magnetic field(s), secured to the object, and forming a sensor ( ), each of the coils belonging to a channel of the sensor. Such a device comprises means:&mdash;(1) of simultaneous and continuous emission of fields, on the coils of the first assembly;&mdash;of measurement, on the channels of the sensor, of the vector sum of the fields emitted and of disturbing fields produced by the environment;&mdash;of evaluation of the disturbing fields;&mdash;of estimation of the fields emitted in an undisturbed environment, by elimination of the disturbing fields evaluated in the vector sum;&mdash;(2) of calculation of the position and the orientation of the object in the reference frame.

Magnetic device and method for determining orientation

A method for determining a position and an orientation of a system that is mobile with respect to a transmitter of an electromagnetic field, the mobile system being placed in a carrier and being linked to a magnetic field sensor. The method including a first step of analytic modeling of the electromagnetic fields as a function of the coordinates of the sensor, a first field (B.sub.0) being created by the transmitter, a second field (B.sub.1) being created by the electrical currents induced in the carrier by the first field (B.sub.0), and a third field (B.sub.2) being created by the electrical currents induced in the mobile system by the first two fields (B.sub.0 +B.sub.1), the magnetic effect of each field (B.sub.0, B.sub.1, B.sub.2) being characterized independently of the effects of the other fields by the coefficients of a model thereof. The method further including a second step of real-time computation of the position and orientation of the sensor by using a current measurement of the electromagnetic field at the sensor and by using the models of the fields (B.sub.0, B.sub.1, B.sub.2) from the first step, the position and orientation of the sensor being defined from a measured field (B.sub.m) from which the third field (B.sub.2) is deduced. The method has applications in determining the position and orientation of the line of sight in a helmet visor.

Method to determine the position and orientation of a mobile system,

The disclosure relates to a method of compensation of perturbations of magnetic field measurements made by a sensor (C) caused by sources of perturbation (S.sub.1, S.sub.2, S.sub.3, . . . S.sub.k) attached to the sensor. The method utilizes a first stage that expresses the perturbation caused by each of the sources, that are situated in any given ambient magnetic field, as an explicit function of the average magnetic field at the position of the source so as to build a model that can be used to calculate its perturbation at the center of the sensor, a second stage, said sensor being located in the magnetic field to be measured, to determine the perturbation caused by each of the sources of perturbation by using its model and knowing the average magnetic field at this position, a third stage that sums the perturbations of all the sources of perturbation, and a fourth stage that subtracts this sum from the measurement made by the sensor. The invention is applicable to systems requiring precise measurement of a magnetic field, notably in the case of the determination of the position and orientation of aircraft pilot helmet aiming devices.

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Merignac, France

Jean-Louis Lescourret