Patent classifications
G01C19/5755
Micromechanical device including a stop spring structure
A micromechanical device including a substrate, a movable mass, and a stop spring structure, which includes a stop. The substrate includes a substrate surface in parallel to a main extension plane and the movable mass is situated movably above the substrate surface in relation to the substrate. The stop spring structure is connected to the movable mass. The stop is designed to strike against the substrate surface in the event of a deflection of the movable mass in a z direction, perpendicular to the main extension plane. The stop spring structure, at the location of the stop, includes a first spring constant, a second spring constant, in parallel to the main extension plane, and a third spring constant, in parallel to the main extension plane and perpendicular to the x direction. The first spring constant is greater than the second spring constant and/or is greater than the third spring constant.
SENSOR SYSTEM AND METHOD FOR COMPENSATING FOR AN OFFSET OF AN ANGULAR RATE SIGNAL
A sensor system. The sensor system comprises a MEMS gyroscope, comprising at least: a seismic mass, which can be excited to vibrate and has at least one electrode assembly for capacitively detecting a measurement signal, a drive circuit for generating a drive voltage for exciting and maintaining a defined vibratory movement of the seismic mass, there being a parasitic capacitive coupling between the drive circuit and the at least one electrode assembly, a detection circuit for reading out the measurement signal and for generating an angular rate signal on the basis of the measurement signal, characterized by circuitry means for compensating for an offset of the angular rate signal on the basis of the drive voltage.
SENSOR SYSTEM AND METHOD FOR COMPENSATING FOR AN OFFSET OF AN ANGULAR RATE SIGNAL
A sensor system. The sensor system comprises a MEMS gyroscope, comprising at least: a seismic mass, which can be excited to vibrate and has at least one electrode assembly for capacitively detecting a measurement signal, a drive circuit for generating a drive voltage for exciting and maintaining a defined vibratory movement of the seismic mass, there being a parasitic capacitive coupling between the drive circuit and the at least one electrode assembly, a detection circuit for reading out the measurement signal and for generating an angular rate signal on the basis of the measurement signal, characterized by circuitry means for compensating for an offset of the angular rate signal on the basis of the drive voltage.
DRIVING CIRCUIT FOR CONTROLLING A MEMS OSCILLATOR OF RESONANT TYPE
A driving circuit for controlling a MEMS oscillator includes a digital conversion stage to acquire a differential sensing signal indicative of a displacement of a movable mass of the MEMS oscillator, and to convert the differential sensing signal of analog type into a digital differential signal of digital type. Processing circuitry is configured to generate a digital control signal of digital type as a function of the comparison between the digital differential signal and a differential reference signal indicative of a target amplitude of oscillation of the movable mass which causes the resonance of the MEMS oscillator. An analog conversion stage includes a ΣΔ DAC and is configured to convert the digital control signal into a PDM control signal of analog type. A filtering stage of low-pass type, by filtering the PDM control signal, generates a control signal for controlling the amplitude of oscillation of the movable mass.
DRIVING CIRCUIT FOR CONTROLLING A MEMS OSCILLATOR OF RESONANT TYPE
A driving circuit for controlling a MEMS oscillator includes a digital conversion stage to acquire a differential sensing signal indicative of a displacement of a movable mass of the MEMS oscillator, and to convert the differential sensing signal of analog type into a digital differential signal of digital type. Processing circuitry is configured to generate a digital control signal of digital type as a function of the comparison between the digital differential signal and a differential reference signal indicative of a target amplitude of oscillation of the movable mass which causes the resonance of the MEMS oscillator. An analog conversion stage includes a ΣΔ DAC and is configured to convert the digital control signal into a PDM control signal of analog type. A filtering stage of low-pass type, by filtering the PDM control signal, generates a control signal for controlling the amplitude of oscillation of the movable mass.
High stability angular sensor
An angular rate sensor. The sensor includes a Coriolis vibratory gyroscope (CVG) resonator, configured to oscillate in a first normal mode and in a second normal mode; a frequency reference configured to generate a reference signal; and a first phase control circuit. The first phase control circuit is configured to: measure a first phase difference between: a first phase target, and the difference between: a phase of an oscillation of the first normal mode and a phase of the reference signal. The first phase control circuit is further configured to apply a first phase correction signal to the CVG resonator, to reduce the first phase difference. A second phase control circuit is similarly configured to apply a second phase correction signal to the CVG resonator, to reduce a corresponding, second phase difference.
Sensing device
A sensing device includes an anchor having a central axis that defines a first radial direction and a second radial direction, and a resonant member flexibly supported by the anchor that includes a main body made of a single-crystal solid. The main body has a first material stiffness in the first radial direction and a second material stiffness in the second radial direction that is less than the first material stiffness. Moreover, the main body has a first component stiffness in the first radial direction and a second component stiffness in the second radial direction that is substantially similar to the first component stiffness. Another sensing device includes a resonant member having a main body that defines an aperture extending through the main body, and an electrode located in the aperture such that a capacitive channel is defined between the electrode and the main body that circumscribes the electrode.
Vibration-Type Angular Velocity Sensor
A vibration-type angular velocity sensor (100) includes a primary side control circuit (2) and a secondary side control circuit (3) which are configured so that a function as the primary side control circuit (2) and a function as the secondary side control circuit (3) are interchangeable, in which an offset value after interchange and an offset value before interchange are symmetric values with respect to a predetermined reference value.
FABRICATION OF MEMS STRUCTURES FROM FUSED SILICA FOR INERTIAL SENSORS
A method for forming a MEMS structure for an inertial sensor from fused silica includes: depositing a conductive layer on one or more selected regions of a first surface of a fused silica substrate, and illuminating areas of the fused silica substrate with laser radiation in a pattern defining features of the MEMS structure for an inertial sensor. A masking layer is deposited at least on the one or more selected regions of the first surface of the fused silica substrate where the conductive layer has been deposited, such that the illuminated areas of the fused silica substrate remain exposed. A first etch of the exposed areas of the fused silica substrate is performed so as to selectively etch the pattern defining features of the MEMS structure for an inertial sensor.
FABRICATION OF MEMS STRUCTURES FROM FUSED SILICA FOR INERTIAL SENSORS
A method for forming a MEMS structure for an inertial sensor from fused silica includes: depositing a conductive layer on one or more selected regions of a first surface of a fused silica substrate, and illuminating areas of the fused silica substrate with laser radiation in a pattern defining features of the MEMS structure for an inertial sensor. A masking layer is deposited at least on the one or more selected regions of the first surface of the fused silica substrate where the conductive layer has been deposited, such that the illuminated areas of the fused silica substrate remain exposed. A first etch of the exposed areas of the fused silica substrate is performed so as to selectively etch the pattern defining features of the MEMS structure for an inertial sensor.