Abstract: 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 (RP) carried by a second fixed or mobile object (P), in a disturbed electromagnetic environment comprising a transmitting antenna (E) with ferromagnetic cores (E-1) having magnetic permeability higher than 10, incorporating sensors (E-3) for measuring the magnetic field Xu actually emitted by the axes of the ferromagnetic cores. A means (4-4) for extracting the signal correlated with the ambient noise XBR (Tk?KbTe)—from the sensors (Sb) fixed in the platform (P), forms, with measurement Xu of 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.

Abstract: 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 (RP) carried by a second fixed or mobile object (P), in a disturbed electromagnetic environment comprising a transmitting antenna (E) with ferromagnetic cores (E-1) having magnetic permeability higher than 10, incorporating sensors (E-3) for measuring the magnetic field Xu actually emitted by the axes of the ferromagnetic cores. A means (4-4) for extracting the signal correlated with the ambient noise XBR (Tk-KbTc)—from the sensors (Sb) fixed in the platform (P), forms, with measurement Xu of 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.

Abstract: The present invention relates to a device for optically detecting position and/or attitude of an object (5) moving in a given travel range (4), said device comprising electro-optical sensors positioned on said object and distributed in groups, called clusters (6), analysis and computation means (2) making it possible to find the position and/or the attitude of said object, electronic image generation means (1) and optical projection means (1) comprising a display and a projection optic. The optical projection means emit, in a projection cone, a clear image (3) 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.

Abstract: The present invention relates to a device for optically detecting position and/or attitude of an object (5) moving in a given travel range (4), said device comprising electro-optical sensors positioned on said object and distributed in groups, called clusters (6), analysis and computation means (2) making it possible to find the position and/or the attitude of said object, electronic image generation means (1) and optical projection means (1) comprising a display and a projection optic. The optical projection means emit, in a projection cone, a clear image (3) 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and device for magnetic measurement of the position and orientation of a mobile object relative to a fixed structure are described. 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.

Abstract: 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.

Abstract: 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.

Abstract: 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:—a first assembly of orthogonal coils (121 to 123) for emitting magnetic field(s), secured to the fixed structure, defining a reference frame;—a second assembly of orthogonal coils for receiving magnetic field(s), secured to the object, and forming a sensor (14), each of the coils belonging to a channel of the sensor.

Abstract: The invention relates to a device for measuring magnetic field(s). This device comprises at least one measurement acquisition pathway (221, 222, 223; 231, 232, 233) comprising a measurement current generator (24), a coil (25), a measurement resistor (26), at least one amplifier (27) and at least one antialiasing filter, delivering a measurement voltage.

Abstract: 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:—a first assembly of orthogonal coils (121 to 123) for emitting magnetic field(s), secured to the fixed structure, defining a reference frame;—a second assembly of orthogonal coils for receiving magnetic field(s), secured to the object, and forming a sensor (14), each of the coils belonging to a channel of the sensor.

Abstract: 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.

Abstract: 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.

Abstract: An oscillator is provided whose oscillation frequency is substantially proportional to the intensity of the ambient magnetic field, and which is used for measuring said magnetic field, and comprising a magnetic resonance magnetrometric probe for detecting a signal at the frequency of said magnetic resonance in response more particularly to a low frequency excitation signal and means for generating said low frequency excitation signal in response to the detected signal, said generation means comprising a loop for locking the phase of said low frequency excitation signal to the phase of said detected signal, and initialization means so that said low frequency excitation signal sweeps a range of frequencies when said loop is not locked.

Abstract: Frequency measurement involves anti-foldover filtering (1) of an analog signal whose frequency i.e. to be measured, followed by sampling of the filtered analog signal and analog-digital conversion of the samples, then digital band-pass filtering (3) on a slaved basis. Associated calculation (4-7) utilizes a linear regression having a single coefficient a for the linear relation between successive digitized samples (2) and to estimate the coefficient a for approximation of the frequency to be measured. The invention is particularly applicable to signals from a probe having nuclear magnetic resonance used in measuring intensity of the terrestrial magnetic field disturbed by metallic masses.