Abstract: The invention relates to an inertial navigation system for a carrier comprising a core comprising gyroscopic sensors making it possible to determine the angular velocity thereof according to three axes defining a reference trihedron, two of the axes defining a reference plane and the third axis being at right angles to this plane. The device comprises command and control means making it possible to rotate the core about the third axis and to determine the direction of the geographic north on the basis of the information supplied by the gyroscopic sensors and by an accelerometer placed in the reference plane; the rotation of the core being performed with a period for which the value of the Allan variance of the stability error of the gyroscopic sensors is lower than a given value guaranteeing the accuracy with which the direction of the geographic north can be known.

Abstract: A gyroscope comprising a resonant structure and a plurality of transducers configured to drive a vibrational mode in the resonant structure and detect vibrations of the resonant structure, wherein at least one of the plurality of transducers comprises a piezoelectric mono crystal.

Abstract: The invention relates to an inertial navigation system for a carrier comprising a core comprising gyroscopic sensors making it possible to determine the angular velocity thereof according to three axes defining a reference trihedron, two of the axes defining a reference plane and the third axis being at right angles to this plane. The device comprises command and control means making it possible to rotate the core about the third axis and to determine the direction of the geographic north on the basis of the information supplied by the gyroscopic sensors and by an accelerometer placed in the reference plane; the rotation of the core being performed with a period for which the value of the Allan variance of the stability error of the gyroscopic sensors is lower than a given value guaranteeing the accuracy with which the direction of the geographic north can be known.

Abstract: A gyroscope comprising a resonant structure and a plurality of transducers configured to drive a vibrational mode in the resonant structure and detect vibrations of the resonant structure, wherein at least one of the plurality of transducers comprises a piezoelectric mono crystal.

Abstract: The present invention is concerned with a method of calibrating a vibrating gyroscope.

Abstract: The invention relates to gyroscopic instruments. The method for calibrating the scale factor of an angular velocity sensor or an axisymmetric vibratory gyroscope, which method uses a control amplitude signal, a control precessional signal CP and a control quadrature signal CQ for exciting the vibration of a resonator on a resonant frequency, involves a first step of pre-calibration which consists of measuring and recording an initial scale factor and the value of an initial control signal, and a second step of measuring the value of the current control signal and establishing a scale factor SF that is corrected on the basis of a proportional relationship involving the initial scale factor SF°, the initial value of the control signal Y° and the current value of the control signal Y° according to the formula SF=SF°Y/Y°.

Abstract: An inertial unit comprising an inertial core (3) that is connected to a control unit (50) and that includes three gyros (9, 10, 11) that are mounted relative to one another so as to have sensing axes (X, Y, Z) that are substantially perpendicular to one another, the gyros being vibrating axisymmetric gyros with hemispherical resonators, the unit being characterized in that the core is mounted on a carousel (2) arranged to drive the inertial core in rotation about an axis of rotation (4) at at least one frequency that corresponds to a minimum for spectral error density of the gyros. An angle-measurement method making use of the unit.

Abstract: The present invention is concerned with a method of calibrating a vibrating gyroscope.

Abstract: An effective and precise method and system for compensation and measurement of a zero-bias in an axisymmetrical CVG (Coriolis Vibrating Gyroscope) is provided. Principal mode is driven according to an X-axis. Angular velocity is measured through Coriolis mode excitation along Y-axis. The sensitive axis of the gyroscope is reversed by 180 degrees by switching input and sense signals. Vibration is then driven along Y-axis and angular velocity is sensed along X-axis. On each position, after an arbitrary period of time, the gyroscope output is stored. Half-difference in outputs between two opposite position gives angular velocity and zero-bias effect is canceled. Half-sum in outputs between two opposite position gives the zero-bias error.

Abstract: An inertial unit comprising an inertial core (3) that is connected to a control unit. (50) and that includes three gyros (9, 10, 11) that are mounted relative to one another so as to have sensing axes (X, Y, Z) that are substantially perpendicular to one another, the gyros being vibrating axisymmetric gyros with hemispherical resonators, the unit being characterized in that the core is mounted on a carousel (2) arranged to drive the inertial core in rotation about an axis of rotation (4) at at least one frequency that corresponds to a minimum for spectral error density of the gyros. An angle-measurement method making use of the unit.

Abstract: A glass-ceramic plate intended in particular to cover heating elements, and having at least one bevel 35 mm or more wide, a method of manufacturing the plate, and a cooking appliance including the plate.

Abstract: The method of calibrating a scale factor of an axially-symmetrical vibrating rate gyro operating by applying an amplitude control signal (CA) and a precession control signal (CP) to a vibrator member (1) set into vibration at a given frequency comprises a pre-calibration step consisting in calculating a reference gain ratio between a drive gain (Gmx) in a first direction and a drive gain (Gmy) in a second direction in modal quadrature with the first direction, and in storing the reference gain ratio, and a calibration step consisting in calculating a value for a measurable magnitude associated with the scale factor by a proportionality relationship including the reference gain ratio, and calculating a corrected scale factor on the basis of the value of the measurable magnitude and the stored reference gain ratio.

Abstract: The method of calibrating a scale factor of an axially-symmetrical vibrating rate gyro operating by applying an amplitude control signal (CA) and a precession control signal (CP) to a vibrator member (1) set into vibration at a given frequency comprises a pre-calibration step consisting in calculating a reference gain ratio between a drive gain (Gmx) in a first direction and a drive gain (Gmy) in a second direction in modal quadrature with the first direction, and in storing the reference gain ratio, and a calibration step consisting in calculating a value for a measurable magnitude associated with the scale factor by a proportionality relationship including the reference gain ratio, and calculating a corrected scale factor on the basis of the value of the measurable magnitude and the stored reference gain ratio.

Abstract: The acceleration measurement system has a first thermal cell optimized in sensitivity and a second thermal cell optimized in passband, which cells are connected to inputs of a servo-control loop including an amplifier presenting gain that varies as a function of input signal frequency.

Abstract: A thermal accelerometer comprising two detector strands having resistivity that is temperature sensitive, a detector member for detecting a temperature difference between the detector strands, a feedback member for establishing temperature equilibrium between the detector strands by supplying the detector strands with pulse feedback signals of variable width, a member for calculating acceleration, and a multiplexer member connected to the detector strands, to the detector member, and to the feedback member so as to perform the following in alternation: measuring the temperature difference between the detector strands; and providing the detector strands with the feedback signals, the widths of the pulse signals being determined by comparing a sawtooth signal with DC signals representative of the temperature difference between the detector strands.

Abstract: The method serves to compensates anisotropy in an inertial rotation sensor comprising a metallized vibrating bell (1) having a bias voltage applied thereto, the vibrating bell (1) having an edge (7) electrodes (5.1, 5.2), and the method comprises the steps of measuring, preferably by multiplexing, the anisotropy between the electrodes and of applying to the electrodes a fraction of the bias voltage that depends on the differences measured between the electrodes.

Abstract: The acceleration measurement system comprises a first thermal cell optimized in sensitivity and a second thermal cell optimized in passband, which cells are connected to inputs of a servo-control loop including an amplifier presenting gain that varies as a function of input signal frequency.

Abstract: A thermal accelerometer comprising two detector strands having resistivity that is temperature sensitive, a detector member for detecting a temperature difference between the detector strands, a feedback member for establishing temperature equilibrium between the detector strands by supplying the detector strands with pulse feedback signals of variable width, a member for calculating acceleration, and a multiplexer member connected to the detector strands, to the detector member, and to the feedback member so as to perform the following in alternation: measuring the temperature difference between the detector strands; and providing the detector strands with the feedback signals, the widths of the pulse signals being determined by comparing a sawtooth signal with DC signals representative of the temperature difference between the detector strands.

Abstract: In an implementation in rate gyro mode, the method includes exciting the vibrating member with a combination of control signals including an amplitude control signal at a frequency twice the resonant frequency, and a quadrature control signal at DC. In free gyro mode, the method includes the steps of applying a combination of signals to common electrodes 5 and of applying the combination in alternation to main electrodes 5.1 and 5.2 and to auxiliary electrodes 7.1 and 7.2 interleaved between the main electrodes.

Abstract: In an implementation in rate gyro mode, the method includes exciting the vibrating member with a combination of control signals including an amplitude control signal at a frequency twice the resonant frequency, and a quadrature control signal at DC. In free gyro mode, the method includes the steps of applying a combination of signals to common electrodes 5 and of applying the combination in alternation to main electrodes 5.1 and 5.2 and to auxiliary electrodes 7.1 and 7.2 interleaved between the main electrodes.