Patent classifications
G01P2015/0862
SENSOR APPARATUS
A sensor apparatus according to an embodiment of the present technology includes a substrate, one or more first IMU sensors, and one or more second IMU sensors. The substrate has a first surface and a second surface opposite to the first surface. The one or more first IMU sensors are arranged on the first surface. The one or more second IMU sensors are arranged on the second surface. By arranging the IMU sensors on both the first surface and the second surface, it is possible to reduce the size the apparatus and to suppress a deformation of the substrate due to heat. This makes it possible to realize a highly accurate measurement based on a detection result (sensing result) of a plurality of IMU sensors.
Resonant accelerometer
In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor located in an opening defined by a body of the proof mass, a spring, a drive electrode, and a sense beam. The spring and the proof mass form a spring system suspended from the anchor. The sense beam oscillates at a particular resonance frequency based on application of a signal to the drive electrode. The MEMS device further includes a support structure coupled to the anchor. The support structure operates as a stress decoupling area and includes a support beam, with the spring corresponding to an end of the support beam that has a reduced thickness. The sense beam has a first end attached to the proof mass and a second end attached to the support beam such that the sense beam is orthogonal to the support beam.
METHOD FOR TEMPERATURE COMPENSATION OF A MICROELECTROMECHANICAL SENSOR, AND MICROELECTROMECHANICAL SENSOR
A method for temperature compensation of a MEMS sensor. The method includes: in a balancing step, a temperature gradient is produced by a thermal element and a first and a second temperature are determined at a first and a second temperature measurement point, wherein a deflection of a movable structure produced by the temperature gradient is measured and a compensation value is ascertained dependent on the first and second temperature and the deflection; in a measurement step, a physical stimulus is measured by way of a deflection of the movable structure and a third and fourth temperature is determined at the first and second temperature measurement points; in a compensation step, a measured value of the physical stimulus is ascertained dependent on the measured deflection, the third and fourth temperature and the compensation value. A method is also provided including: a regulation step, and a measurement step.
Ultra-Low Power Readout Circuit With High-Voltage Bias Generation For MEMS Accelerometer
A motion sensing system uses high-voltage biasing to achieve high resolution with ultra-low power. The motion sensing system consists of a motion sensor, a readout circuit, and a high-voltage bias circuit to generate the optimized bias voltage for the motion sensor. By using the high-voltage bias, the signal from the motion sensor is raised above the readout circuit's noise floor, eliminating the power-hungry amplifier and signal-chopping used in conventional motion sensing systems. The bias circuit, while producing the programmable bias voltages for the motion sensor, also compensates for the process mismatch raised by the high voltage biases.
MULTI-FREQUENCY EXCITATION
Embodiments of multi-frequency excitation are described. In various embodiments, a natural frequency of a device may be determined. In turn, a first voltage amplitude and first fixed frequency of a first source of excitation can be selected for the device based on the natural frequency. Additionally, a second voltage amplitude of a second source of excitation can be selected for the device, and the first and second sources of excitation can be applied to the device. After applying the first and second sources of excitation, a frequency of the second source of excitation can be swept. Using the methods of multi-frequency excitation described herein, new operating frequencies, operating frequency ranges, resonance frequencies, resonance frequency ranges, and/or resonance responses can be achieved for devices and systems.
Electrostatically softened accelerometer spring
Described herein are accelerometers, apparatus and systems incorporating accelerometers, and techniques for electrostatically adjusting a stiffness of a spring system in an accelerometer. Embodiments featuring resonant and/or quasi-static accelerometers are described. In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor, a spring attached to the proof mass, a sense electrode, and a tuning electrode. The spring and the proof mass form a spring system suspended from the anchor. The sense electrode is configured to generate a signal indicating movement of the proof mass based on application of a first signal. The tuning electrode is configured to receive an electrostatic tuning signal, the electrostatic tuning signal being separate from the first signal and providing a negative contribution to an overall stiffness of the spring system. The electrostatic tuning signal can be used to adjust the stiffness based on a measured acceleration.
3-axis accelerometer
A three-axis accelerometer includes a single, integrated mass including at least one lateral (x-y) proof mass and at least one vertical (z) proof mass. The vertical proof mass is arranged as a teeter-totter mass, which is located within the lateral proof mass. The vertical proof mass is mechanically coupled to the lateral proof mass with one or more torsional springs, and the lateral proof mass is mechanically coupled to one or more anchors with one or more lateral springs. The at least one vertical proof mass may be symmetrically positioned about one or more axes of the three-axis accelerometer, so that the 3-axis accelerometer has in-plane symmetry. The three-axis accelerometer may be less susceptible for mechanical cross-talk or noise and may provide a smaller packaged solution for sensing acceleration in three directions.
MICROMECHANICAL SENSOR ELEMENT
A micromechanical sensor element includes a substrate, a first structure movably arranged on the substrate, a second structure movably arranged on the substrate and an electrode arrangement, situated on the substrate in a fixed manner, which includes at least one first electrode. The movably arranged structures are coupled with each other by at least one coupling element in such a way that, upon a deflection of the first movably arranged structure along a first direction, the second movably arranged structure undergoes a deflection along an opposite direction. The first electrode includes a plurality of electrode surfaces. The movably arranged structures each include a plurality of movable electrode surfaces. The substrate-fixed electrode surfaces and the movable electrode surfaces engage with each other. The movable electrode surfaces are each situated on sides of the electrode surfaces of the substrate-fixed electrode arrangement facing away from the movably arranged structures.
ACCELEROMETER ELEMENT FOR DETECTING OUT-OF-PLANE ACCELERATIONS
An accelerometer element is provided that includes a body, a mass and a spring system that couples the mass to the body. The spring system configures the mass to rotate reciprocally about a rotary axis. The mass includes a volume of a bulk material that forms two essentially closed surfaces and incorporates between those two closed surfaces one or more weight elements, each of which is formed of a substance whose weight per unit volume is different from weight per unit volume of the bulk material. The weight elements are incorporated in the mass so that the centre of gravity of the mass is offset from the rotary axis in an in-plane direction and the centre of gravity of the mass and the rotary axis are at the same level within the mass in the out-of-plane direction.
Decoupling structure for accelerometer
Accelerometer including a decoupling structure for fixing the accelerometer on a package and a MEMS sensor chip for measuring an acceleration. The chip is supported by the decoupling structure and includes a sensor wafer layer of a semiconductor material. The decoupling structure forms a bottom portion for fixing the decoupling structure on the package and a top portion fixed to the sensor wafer layer so that the chip is arranged above the decoupling structure. A width of the top portion in a planar direction is smaller than a width of the bottom portion and/or the sensor wafer layer in the planar direction. The decoupling structure is made of the same semiconductor material as the sensor wafer layer. The centre point of the top portion is arranged in a central region of the bottom portion. The chip includes a hermetically closed cavity which includes a seismic mass of the chip.