Abstract: The invention relates to a method for calibrating a magnetometer including the following steps: the magnetometer travels through (Si) a set of path positions, acquisition (S2) by the magnetometer of a plurality of measurements of the magnetic field, provision of trajectory information (S3) representative of the location and the orientation of a point integral with the magnetometer, matching up (S4) of the measurements of the magnetic field with the trajectory information, determination (S5) of calibration parameters of the magnetometer by the minimisation of a cost function involving, for a plurality of determination times, at least said calibration parameters, a measurement of the magnetic field, and a relationship linking the change in a magnetic field with the change in the location and in the orientation of the magnetometer derived from the trajectory information.

Abstract: The present invention relates to a method for locating an object (1) integral with a triaxial magnetic sensor (2) moving in a magnetic field generated by a set of at least three triaxial magnetic generators (3) static in a common reference frame, the method being characterised in that it includes the steps of: (a) For each generator (3) determining as a function of magnetic field measurements acquired by the sensor (2) and associated with said generator (3) a position of said sensor (2) in said common reference frame; (b) Calculating for each generator (3) a parameter representative of an error on said determined position of the sensor (2) for the generator (3); (c) Selecting a sub-set of the set of generators (3) as a function of said parameters estimated for each of the generators (3) said selected sub-set of the set of generators (3) including each generator (3) for which said estimated parameter is less than at least one reference threshold; (d) Estimating the position of the object (1) by merging the

Abstract: The present invention relates to a method for estimating the movement of an object (1) moving in an environment (?) and an ambient magnetic field, the method being characterised in that it includes the steps of: (a) Acquisition: by inertial measurement means (24) fixed with respect to said object (1), of at least one component of an acceleration and/or an angular velocity of the object (1), designated inertial datum; by magnetic measurement means (20) fixed with respect to said object (1), of at least one component of the magnetic field and/or an i-th derivative of the magnetic field, at the magnetic measurement means (20), designated magnetic datum; by optical acquisition means (26) fixed with respect to said object (1), of consecutive images of the environment (?), designated vision datum; (b) Estimation by the data processing means (21, 31, 41) of at least one component of the movement of said object (1) using the inertial datum, as well as the magnetic datum and/or the vision datum.

Abstract: The invention relates to a method for determining a heading, in which a magnetic field is measured by at least one magnetometer and a magnetic heading is determined from said measurement and in which calculation means implement a processing calculating, for each measurement of magnetic heading, a value for characterising the heading thereby determined, characterised in that said characterisation value is a monotone function of a norm of the measured magnetic field gradient, said value being used in the determination of the heading.

Abstract: The present invention relates to a method for calibrating a magnetometer (3) in which the magnetometer (3) is arranged inside the windings (21) of a generator (2), a magnetic field being generated by the generator (2), a series of measurements of the magnetic field with the magnetometer (3) being carried out by varying the position of the magnetometer (3) and/or the electric currents in the windings (21) between each measurement, the electric currents applied in the windings (21) also being measured, a parametric transfer model being generated from a parametric measurement model of the magnetometer including parameters for calibrating the magnetometer and a parametric model of the magnetic field, the parameters for calibrating the magnetometer (3) being calculated by an optimisation algorithm from the parametric transfer model and measurements of the magnetic field by the magnetometer and measurements of the currents in the windings.

Abstract: The invention relates to a magnetic field measurement by a set of magnetometers (20) which are linked to a same moveable support and which have different orientations of eigendirections with respect to this support. The processing means implement, during a measurement in a given position and orientation of the support and of the set of magnetometers, a determination, for each magnetometer, of the orientation deviation between the eigendirections of the magnetometer and the “candidate” magnetic field, a determination of the magnetometer for which this deviation is minimal, the magnetic field measured by this sensor being selected as the magnetic field measured by the set of magnetometers. The magnetometers (20) are distributed in space in order to cover a maximum of different orientations.

Abstract: The invention relates to the determination of heading by magnetic sensors, in which a magnetic field is measured by magnetometers and calculation means implement a recursive processing calculating for a given sampling time: an estimation of a heading prediction which is a function of the heading determined at the preceding sampling time, a resetting of the predicted heading thereby estimated as a function of a magnetic heading determined from magnetometer measurements. During said resetting, the calculation means estimate the amplitude of the resetting as a function: of a model of the change in magnetic disturbances between two sampling times, and of an a priori estimation of the amplitude of the disturbances.

Abstract: The present invention relates to a method for estimating the movement of an object (1) moving in an ambient magnetic field, the method being characterised in that it comprises the steps of: (a) Acquiring by magnetic measurement means (20) integral with said object (1) at least one component: of the magnetic field and/or of at least one i-th derivative of the magnetic field, with n+1?i?1, n?1, ?at the level of the magnetic measurement means (20); (b) Estimating by the data processing means (21, 31, 41) at least one component of the movement of said object (1) using at least one component of the equation ?{dot over (n)}B=fn(?)·?nB+gn(?n+1B)·V, where ?nB is an n-th derivative of the magnetic field, ? the instantaneous angular velocity, V the instantaneous linear velocity, and fn and gn predetermined functions.

Abstract: The present invention relates to a method for estimating the relative orientation between a tibia (11a) and a femur (11b) of a lower limb (10) of a person (1), the method being characterised in that it comprises the steps of: (a) During at least one reference movement of said lower limb (10) from a reference position, acquiring by first inertial measuring means (20a) integral with the tibia (11a) and by second inertial measuring means (20b) integral with the femur (11b) reference accelerations and angular velocities; (b) Estimating a plurality of morphological parameters of said lower limb (10), as a function of said measured reference accelerations and angular velocities; (c) Determining a relative orientation in said initial position between said tibia (11a) and femur (11b), as a function of said estimated morphological parameters of said lower limb (10); (d) During a working movement of said lower limb (10) from an initial position, acquiring by the first inertial measuring means (20a) and the second iner

Abstract: The present invention relates to a method for estimating the physical activity exerted by an upper limb (10) of a person (1), the method being characterised in that it comprises the steps of: (a) Acquiring, by inertial measurement means (20) solidly attached to a forearm (11) of said upper limb (10) of said person (1), an angular speed of said forearm (11); (b) Estimating, by data processing means (21, 31, 41), a torque exerted by the muscles of an arm (12) of the upper limb (1) on said forearm (11) as a function of the measured angular speeds, of an orientation of said forearm (11), and of physical parameters of said forearm (11); (c) Determining, by the data processing means (21, 31, 41), a power exerted by the upper limb (10) as a function of the estimated torque and of the measured angular speed.

Abstract: The present invention relates to a method for estimating the movement of a walking pedestrian (1), the method being characterised in that it comprises the following steps: (a) Acquisition, by inertial-measurement means (20) rigidly connected to a lower limb (10) of said pedestrian (1) and positioned in such a way as to have substantially a movement of rotation with respect to a distal end (11) of said lower limb (10) at least when said distal end (11) of the lower limb (10) is in contact with the ground, of an acceleration and of an angular speed of said lower limb (10); (b) Estimation, by data-processing means (21, 31, 41), of a speed of said lower limb (10) according to said measured acceleration and said measured angular speed.