Patent classifications
G01C19/5755
Gyroscope
A vibrating structure gyroscope includes a permanent magnet, a structure arranged in a magnetic field of the permanent magnet and arranged to vibrate under stimulation from at least one primary drive electrode and a drive system that includes: one primary drive electrode arranged at least one primary sense electrode arranged to sense motion in the vibrating structure and a drive control loop controlling the primary drive electrode dependent on the primary sense electrode. The structure also includes a compensation unit arranged to receive a signal from the drive system representative of a gain in the drive control loop and arranged to output a scale factor correction based on that signal. As the magnet degrades (e.g. naturally over time as the material ages), the magnetic field weakens. To compensate for this, the primary drive control loop will automatically increase the gain.
SENSOR AND ELECTRONIC DEVICE
According to one embodiment, a sensor includes a processor. The processor is configured to acquire a first angle value from an angle gyro sensor and acquire a first angular velocity value from an angular velocity gyro sensor, and perform at least first processing. The first processing includes outputting a second angular velocity value by correcting the first angular velocity value by using a value obtained by filtering a difference between the first angle value and a post-processing angle value. The post-processing angle value is obtained by processing the first angular velocity value.
SENSOR AND ELECTRONIC DEVICE
According to one embodiment, a sensor includes a processor. The processor is configured to acquire a first angle value from an angle gyro sensor and acquire a first angular velocity value from an angular velocity gyro sensor, and perform at least first processing. The first processing includes outputting a second angular velocity value by correcting the first angular velocity value by using a value obtained by filtering a difference between the first angle value and a post-processing angle value. The post-processing angle value is obtained by processing the first angular velocity value.
Sensor
According to one embodiment, a sensor includes a movable member, first, and second counter electrodes, first, and second resistances, and a control device. The movable member includes first and second electrodes and is capable of vibrating. The vibration of the movable member includes first and second components. The first component is along a first direction. The second component is along a second direction crossing the first direction. The first counter electrode opposes the first electrode. The second counter electrode opposes the second electrode. The first resistance includes first and first other end portions. The second resistance includes a second end portion and a second other end portion. The first other end portion is electrically connected to the first counter electrode. The second other end portion is electrically connected to the second counter electrode. The control device includes a controller configured to perform at least a first operation.
LOW-PARASITIC CAPACITANCE MEMS INERTIAL SENSORS AND RELATED METHODS
Microelectromechanical system (MEMS) inertial sensors exhibiting reduced parasitic capacitance are described. The reduction in the parasitic capacitance may be achieved by forming localized regions of thick dielectric material. These localized regions may be formed inside trenches. Formation of trenches enables an increase in the vertical separation between a sense capacitor and the substrate, thereby reducing the parasitic capacitance in this region. The stationary electrode of the sense capacitor may be placed between the proof mass and the trench. The trench may be filled with a dielectric material. Part of the trench may be filled with air, in some circumstances, thereby further reducing the parasitic capacitance. These MEMS inertial sensors may serve, among other types of inertial sensors, as accelerometers and/or gyroscopes. Fabrication of these trenches may involve lateral oxidation, whereby columns of semiconductor material are oxidized.
LOW-PARASITIC CAPACITANCE MEMS INERTIAL SENSORS AND RELATED METHODS
Microelectromechanical system (MEMS) inertial sensors exhibiting reduced parasitic capacitance are described. The reduction in the parasitic capacitance may be achieved by forming localized regions of thick dielectric material. These localized regions may be formed inside trenches. Formation of trenches enables an increase in the vertical separation between a sense capacitor and the substrate, thereby reducing the parasitic capacitance in this region. The stationary electrode of the sense capacitor may be placed between the proof mass and the trench. The trench may be filled with a dielectric material. Part of the trench may be filled with air, in some circumstances, thereby further reducing the parasitic capacitance. These MEMS inertial sensors may serve, among other types of inertial sensors, as accelerometers and/or gyroscopes. Fabrication of these trenches may involve lateral oxidation, whereby columns of semiconductor material are oxidized.
MEMS gyroscope with calibration of the scale factor in real time and calibration method thereof
The MEMS gyroscope has a mobile mass carried by a supporting structure to move in a driving direction and in a first sensing direction, perpendicular to each other. A driving structure governs movement of the mobile mass in the driving direction at a driving frequency. A movement sensing structure is coupled to the mobile mass and detects the movement of the mobile mass in the sensing direction. A quadrature-injection structure is coupled to the mobile mass and causes a first and a second movement of the mobile mass in the sensing direction in a first calibration half-period and, respectively, a second calibration half-period. The movement-sensing structure supplies a sensing signal having an amplitude switching between a first and a second value that depend upon the movement of the mobile mass as a result of an external angular velocity and of the first and second quadrature movements. The first and second values of the sensing signal are subtracted from each other and compared with a stored difference value to supply information of variation of the scale factor.
MEMS gyroscope with calibration of the scale factor in real time and calibration method thereof
The MEMS gyroscope has a mobile mass carried by a supporting structure to move in a driving direction and in a first sensing direction, perpendicular to each other. A driving structure governs movement of the mobile mass in the driving direction at a driving frequency. A movement sensing structure is coupled to the mobile mass and detects the movement of the mobile mass in the sensing direction. A quadrature-injection structure is coupled to the mobile mass and causes a first and a second movement of the mobile mass in the sensing direction in a first calibration half-period and, respectively, a second calibration half-period. The movement-sensing structure supplies a sensing signal having an amplitude switching between a first and a second value that depend upon the movement of the mobile mass as a result of an external angular velocity and of the first and second quadrature movements. The first and second values of the sensing signal are subtracted from each other and compared with a stored difference value to supply information of variation of the scale factor.
Sensing device
A sensing device includes a resonant member that is movable in a first mode and a second mode, and an electrode. The resonant member has a capacitive surface portion that faces and is capacitively coupled to a capacitive surface portion of the electrode. Displacement for each point along the capacitive surface portion of the resonant member in the first mode is substantially tangent to the point.
MEMS MOTION SENSOR AND METHOD OF MANUFACTURING
A MEMS motion sensor and its manufacturing method are provided. The sensor includes a MEMS wafer including a proof mass and flexible springs suspending the proof mass and enabling the proof mass to move relative to an outer frame along mutually orthogonal x, y and z axes. The sensor includes top and bottom cap wafers including top and bottom cap electrodes forming capacitors with the proof mass, the electrodes being configured to detect a motion of the proof mass. Electrical contacts are provided on the top cap wafer, some of which are connected to the respective top cap electrodes, while others are connected to the respective bottom cap electrodes by way of insulated conducting pathways, extending along the z axis from one of the respective bottom cap electrodes and upward successively through the bottom cap wafer, the outer frame of the MEMS wafer and the top cap wafer.