Sagem Defense Securite

Safran Electronics & Defense

Sagem Sa

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Safran

Alain Jeanroy

Philippe Onfroy

Alain Renault

Jean-Michel Caron

Audrey Berthelot

Guillaume Lehee

Vincent Ragot

Paul Vandebeuque

Mikaël Colin

Pierre Leger

Jean-Sébastien Mace

Michel James

Olivier Vancauwenberghe

Angular sensor with vibrating resonator includes a supporting structure, a first mass and a second mass which are concentric, and mechanical springs arranged symmetrically in pairs, the pairs themselves being arranged symmetrically with respect to one another. Each spring comprises a first elastic leaf and a second elastic leaf which are connected to one another by one end, the first elastic leaf of one of the springs of each pair being parallel to the second elastic leaf of the other of the springs of the same pair. The four elastic leaves of at least one pair comprise two adjacent pairs of leaves making an angle of approximately 45° between them. The sensor is not provided with electrostatic springs.

Sensor with mechanical compensation frequency anisotropy

A microdevice () comprising a movable element () capable of moving relative to a fixed part (), produced in first and second layers of material () arranged one above the other such that the movable element comprises a portion () of the first layer and a portion () of the second layer secured to each other, and wherein the movable element is suspended from the fixed part by a suspension structure () formed in the first and/or second layer of material.

Microdevice comprising at least two movable elements

An inertial angular sensor of MEMS type has a support of at least two masses which are mounted movably with respect to the support, at least one electrostatic actuator and at least one electrostatic detector. The masses are suspended in a frame itself connected by suspension means to the support. The actuator and the detector are designed to respectively produce and detect a vibration of the masses, and a method for balancing such a sensor provided with at least one load detector mounted between the frame and the support and with at least one electrostatic spring placed between the frame and one of the masses and slaved so as to ensure dynamic balancing of the sensor as a function of a measurement signal of the load sensor.

Inertial angular sensor of balanced MEMS type and method for balancing such a sensor

A MEMS type inertial sensor comprising a support structure having at least a first seismic body and a second seismic body connected thereto by resilient means in order to be movable in a suspension plane, transducers for maintaining the seismic bodies in vibration and for determining movements of the seismic bodies in the suspension plane, and a control unit connected to the transducers by electrical conductor means. The transducers comprise at least one electrode secured to the first seismic body and at least one electrode secured to the second seismic body, the two electrodes being arranged to enable relative movements of the seismic bodies relative to each other in the suspension plane to be measured directly.

Sensor including moving masses and means for detecting relative movements of the masses

The invention relates to a vibrating MEMS inertial angular sensor including a substrate for supporting at least two mass bodies mounted to bear mobile relative to the substrate and associated with at least one electrostatic actuator and at least one electrostatic detector. The sensor includes first means for suspending the mass bodies relative to the substrate and means for coupling the mass bodies together. The substrate is connected to a stationary rack by second suspension means.

MEMS balanced inertial angular sensor and method for balancing such a sensor

An inertial sensor comprising a frame to which at least two seismic bodies are connected by resilient means so as to be movable in a suspension plane, and transducers to keep the seismic bodies vibrating and to determine a relative movement of the seismic bodies relative to one another, characterized in that the seismic bodies have a single shape and a single mass, and in that the seismic bodies comprise interlocking parts such that the seismic bodies are nested inside one another while being movable in the suspension plane relative to the other of the seismic bodies, with the seismic bodies having centers of gravity that coincide with one another. A method for manufacturing such a sensor.

Inertial sensor with nested seismic masses and method for manufacturing such a sensor

A sensor comprising: a stand; a first body movable along a sensing axis; two pairs of second bodies arranged symmetrically relative to the first body and along the sensing axis; transducers for detecting a position of the first body relative to the stand, for setting the second bodies into vibration along a vibration axis, and for detecting respective vibration frequencies of the second bodies; and surface electrostatic coupling means connecting each second body to the first body in such a manner that a movement of the first body relative to the stand along the sensing axis gives rise respectively to an increase and to a decrease in the electrostatic coupling for one and the other of the pairs of second bodies. Methods of controlling such a sensor.

Sensor with moving sensitive element having mixed vibrating and pendular operation, and methods for controlling such a sensor

A vibrating gyroscope has a base and a resonator. The resonator includes a body of generally cylindrical shape terminating in a face. The resonator is capable of vibrating according to a first vibration mode having antinodes distributed on n axes, and a second vibration mode having antinodes distributed on n other axes. The face of the resonator has two piezoelectric assemblies on each axis of the first and of the second vibration modes. Each piezoelectric assembly has at least one piezoelectric element capable of exciting the resonator in vibration and at least one piezoelectric element capable of detecting vibrations of the resonator at the same time.

Vibrating gyroscope and treatment process

A vibrating gyroscope having a base, and a resonator. The resonator includes a body of generally cylindrical shape terminating in a distal face to the side opposite the base. The face includes at least one through hole, a plurality of piezoelectric elements placed in contact with the resonator, vibration control and processing modules arranged at least in part on the base, and at least one electrical connection passing through the body of the resonator via the hole, and electrically connecting the modules of the base and the plurality of piezoelectric elements for controlling and measuring the vibration of the resonator.

Vibrating gyroscope and corresponding manufacturing process

A resonator for an angular parameter sensor, the resonator comprising a bell of electrically-insulating material provided with a central stem and an electrically-conductive layer, the conductive layer comprising branches extending from a central portion of the bell to a peripheral edge of the bell, the number of said branches being a prime number not less than seven.

Resonator for a vibratory sensor of an angular parameter

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 () 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.

Method for calibrating a scale factor in an axisymmetrical vibrating gyrometer

The resonator comprises a shella having a poleheld by a support rod, the shell having an annular edgedefined by an inside surfaceand an outside surfacethat are geometrically similar and that extend around a common axis of revolution R, the inside surface and the outside surface being offset relative to each other along the axis of revolution in such a manner that the shell presents a thickness E along the annular edgethat is greater than the thickness e that it presents in the vicinity of the pole

Resonator particularly for a vibrating gyroscope

The method serves to compensates anisotropy in an inertial rotation sensor comprising a metallized vibrating bell () having a bias voltage applied thereto, the vibrating bell () having an edge () electrodes (), 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.

Method of compensating anisotropy in a vibrating-bell inertial rotation sensor

A gyroscopic sensor comprising: a sensing element ( ) associated with detection and excitation electrodes ( ); conductive rods ( ) connected in particular to said electrodes ( ); a protective housing ( ) enclosing the sensing element ( ) and the electrode ( ) and having insulating feed-throughs ( ) for the conductive rods ( ); and support means interposed between the housing ( ) and the sensing element ( ) with the electrodes ( ); the sensor being characterized in that said support means are constituted by the conductive rods ( ) themselves, which are made so as to be elastically deformable.

Gyroscopic sensor

The gyroscopic sensor has a bell-shaped resonator which is fixed along its axis on a substrate. It has a circular edge lying in a plane perpendicular to the axis and at a distance from the point where the resonator is fixed. The substrate carries detection and excitation electrodes that co-operate with the resonator. The detection electrodes are sensitive to an axial component of resonator vibration and the energization electrodes cause vibration at resonance by exerting axial forces.

Growing community of inventors

Boulogne Billancourt, France

Alain Jeanroy