Abstract: 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.

Abstract: Disclosed is a piezoelectric washer intended for an accelerometer sensor having a ceramic body and a conductive electrode on each of two opposing faces, an electrical resistance being to be established between the two conductive electrodes. The ceramic body has, on its outer contour, a resistive path connecting the conductive electrodes to one another with a predetermined length and cross-section of the resistive path according to the resistance to be established between the two conductive electrodes.

Abstract: A method for installing an inertial sensor unit includes: attaching a substrate to a structure with a magnet; and attaching a case accommodating an inertial sensor, to the substrate. The case is provided with a first attachment part. The substrate is provided with a second attachment part. In the attaching the case, the first attachment part and the second attachment part are fitted together to attach the case to the substrate. The inertial sensor has a base part, a moving part coupled to the base part, a physical quantity detection element arranged at the moving part, and a mass part arranged at the moving part. The mass part is made of a non-magnetic material.

Abstract: A transducer structure for converting a deformation along an axis into a corresponding deformation on a plane orthogonal to the axis itself, including: two end plates facing each other and aligned along a common reference axis (X); connection members projecting radially from each end plate according to respective different directions; lateral bars connecting the end plates to one another through two connection members. The connection members are deformable within respective deformation planes to allow relative movements between the end plates and the lateral bars such as to convert an axial movement of mutual approach between the two end plates into a corresponding radial movement of the lateral bars away from the reference axis (X), and vice-versa.

Abstract: Disclosed are devices and methods using the devices for collecting biological and other specimens or substances from surfaces being interrogated for such contamination. Particular device aspects comprise a handle, with a frame at one end receptive to insertion and removal of a sampling medium (collecting member) intended for wiping against a surface, with the sampling member being held in place by passive projections from the frame without the need for the use of glue or articulating or moving parts. The Frame and/or the collecting member may also comprise at least one attached or integral scraping member or surface for breaking biofilms and thus making the microbes or other substances more available to being sampled by the collecting member.

Abstract: A self-diagnosis method for a vibration sensor attached to vibrating equipment includes measuring vibration data of the vibrating equipment by the vibration sensor, integrating the vibration data, and diagnosing whether or not the vibration sensor is abnormal by comparing an integrated value of the vibration data with a reference value.

Abstract: An acceleration sensor core unit 1 includes a circuit board 3 and metallic plates 4, 5. The circuit board 3 is made of an epoxy resin, and an acceleration sensor 11 for detecting vibration acceleration in an arrow 105 direction is mounted thereon. The circuit board 3 is sandwiched between the metallic plates 4, 5. Ring-shaped metallic spacers 7a to 7c and ring-shaped metallic spacers 8a to 8c are respectively interposed between the circuit board 3 and the metallic plate 4 and between the circuit board 3 and the metallic plate 5. The circuit board 3 is screwed to each of the metallic plates 4, 5 at three positions. Thus, it is possible to reliably fix the circuit board 3 to the metallic plates 4, 5 with a small attachment space. In this way, rigidity as the acceleration sensor core unit 1 can be secured.

Abstract: A MEMS accelerometer includes proof masses that move in-phase in response to a sensed linear acceleration. Self-test drive circuitry imparts an out-of-phase movement onto the proof masses. The motion of the proof masses in response to the linear acceleration and the self-test movement is sensed as a sense signal on common sense electrodes. Processing circuitry extracts from a linear acceleration signal corresponding to the in-phase movement due to linear acceleration and a self-test signal corresponding to the out-of-phase movement due to the self-test drive signal.

Abstract: An apparatus and method for measuring a structural angular acceleration based on dynamic centrifugal force measurement belong to the technical field of angular acceleration measurement. The apparatus has a solid ball. The solid ball can move freely along the radial direction of the outer wall packaging hood. The elastic block is used as a stress base. A rod for lateral limit and connection is used for connecting the rigid block and a pulley and limiting the displacement of solid ball so that the solid ball can only move longitudinally along the apparatus. The rigid block can move freely due to the pulley. Measurement of a transient angular acceleration is converted into dynamic measurement of the centrifugal force of the solid ball. Through the above design, the dynamic angular acceleration of the structure caused by dynamic load can be relatively accurately calculated.

Abstract: An unmanned aircraft includes a circuit board with an inertia sensor, and a weight block configured to have a flat surface and a recess formed on the flat surface, and a housing assembly configured to form an inner chamber to accommodate the circuit board and the weight block. The circuit board is embedded in the recess by fixedly bonding to the flat surface through adhesion.

Abstract: A microelectromechanical gyroscope includes a drive loop having a drive element and a drive loop circuitry. The drive loop circuitry includes a clock generating circuitry for generating from the quadrature-phase detection signal a test clock signal, an angular rate phase demodulation signal and a quadrature phase demodulation signal. A sense loop includes a sense element and sense loop circuitry for detecting angular rate and producing a force-feedback signal. A test signal generator receives a quadrature-phase detection signal to be used as a quadrature-phase carrier signal and the test clock signal A summing element sums a test signal with the force-feedback signal to form a sense feedback signal. A rate phase demodulator produces a rate signal by demodulating a sense signal received from the sense loop with the angular rate phase demodulation signal, and a quadrature-phase demodulator produces a quadrature-phase output signal.

Abstract: This disclosure is related to devices, systems, and techniques for determining an acceleration of a vibrating beam accelerometer (VBA). For example, a system includes processing circuitry configured to receive, from a first resonator, one or more electrical signals indicative of a frequency of a first mechanical beam and a frequency of a second mechanical beam, determine, based on the one or more electrical signals, the frequency of the first mechanical beam and the frequency of the second mechanical beam, and calculate, based on the frequency of the first mechanical beam and the frequency of the second mechanical beam, an acceleration of a proof mass assembly.

Abstract: Some embodiments relate to a vibration sensor. The vibration sensor comprises: a sensor base to couple to a vibration source; a piezoelectric transducer coupled on a first side of the transducer to the sensor base; at least one conductor coupled to the piezoelectric transducer; and a seismic weight positioned on a second side of the piezoelectric transducer; wherein the sensor base, the piezoelectric transducer and the seismic weight are aligned along an axis and arranged so that relative movement between the sensor base and the seismic weight arising from the vibration source causes a current to be generated in the piezoelectric transducer and an output signal corresponding to the generated current is detectable on the at least one conductor.

Abstract: A MEMS accelerometer includes a suspended spring-mass system that has a frequency response to accelerations experienced over a range of frequencies. The components of the suspended spring-mass system such as the proof masses respond to acceleration in a substantially uniform manner at frequencies that fall within a designed bandwidth for the MEMS accelerometer. Digital compensation circuitry compensates for motion of the proof masses outside of the designed bandwidth, such that the functional bandwidth of the MEMS accelerometer is significantly greater than the designed bandwidth.

Abstract: An inertial measurement apparatus has mechanically bendable beams that have an isosceles trapezoid cross-section. The apparatus has a resonant member having a perimeter at least partially defined by a sidewall slanted at a first angular value and at least one electrode disposed adjacent, and parallel, to the sidewall and separated therefrom by a capacitive gap.

Abstract: The disclosure describes a z-axis gyroscope where a proof mass is suspended from a peripheral suspender and a central suspender. The peripheral suspender forms a truncated triangle around the proof mass, and the central suspender extends through the truncated corner of the triangle formed by the peripheral suspender. The proof mass is driven into a primary oscillation mode by one or more piezoelectric drive transducers located on the peripheral suspender. One or more piezoelectric sense transducers located on the base of the peripheral suspender are configured to detect the secondary oscillation mode of the proof mass.

Abstract: An inertial measurement apparatus has mechanically bendable beams that have an isosceles trapezoid cross-section. The apparatus has a resonant member having a perimeter at least partially defined by a sidewall slanted at a first angular value and at least one electrode disposed adjacent, and parallel, to the sidewall and separated therefrom by a capacitive gap.

Abstract: A resonant accelerometer includes a proof mass, one or more springs connecting the proof mass to an anchor, and one or more capacitive transduction gaps providing a void or space between the movable proof mass and a corresponding fixed electrode, wherein the static displacement of the proof mass in response to acceleration applied to the anchor modifies the electrostatic stiffness imparted by one or more of the capacitive transduction gaps on the proof mass, resulting in a corresponding change in the resonance frequency of the resonant accelerometer.

Abstract: A method for mounting an inertial sensor unit includes: mounting a substrate to a structure; and mounting, to the substrate, a case in which an inertial sensor is accommodated, wherein the case is provided with a first mounting portion, the substrate is provided with a second mounting portion, and in the mounting of the case, the first mounting portion and the second mounting portion fit together, whereby the case is mounted to the substrate.

Abstract: Apparatus and associated methods relate to measuring density of aircraft fuel. The aircraft fuel is circumferentially pumped about an impeller axis by a centrifugal pump. Differential pressure of the aircraft fuel is measured between two different points within the centrifugal pump, each a different radial distance from an impeller axis. Rotational frequency of the impeller of the centrifugal pump is measured. Density of the aircraft fuel is calculated based on the rotational frequency and the differential pressure.