41 results about "Proof mass" patented technology

An accelerometer including: a housing; a proof mass; a piezoelectric material; a support member for holding the proof mass a predetermined distance from the piezoelectric material, the proof mass being rotatably disposed relative to the housing and having a center of gravity offset from an axis of rotation of the support member; a first biasing material for biasing the proof mass towards the piezoelectric material and against the support member; and a second biasing material for biasing the proof mass at the predetermined distance from the piezoelectric material. When a level of acceleration of the proof mass is less than or equal to an acceleration level that is to be measured, the second biasing material is configured to force the support member to rotate to disengage the proof-mass and the first biasing material to move the proof-mass to contact the piezoelectric material.

Embodiments of the present disclosure provide a fully decoupled three-axis MEMS gyroscope and an electronic product. The gyroscope comprises: a substrate, and an X / Y proof mass, Z proof masses, driving structures and Z decoupling masses that are fixed on the substrate; the X / Y proof mass is arranged around outer sides of the Z proof masses, the driving structures and the Z decoupling masses; the Z proof masses are oppositely arranged in an x-axis direction; the driving structures are oppositely arranged at outer sides of the Z proof masses in the x-axis direction; and the Z decoupling masses are oppositely arranged at inner sides of the Z proof masses in the x-axis direction. The X / Y proof mass is elastically connected to the driving structures adjacent thereto, the Z proof masses are elastically connected to the driving structures adjacent thereto, and the Z decoupling masses are elastically connected to the Z proof masses adjacent thereto. The gyroscope improves the Coriolis conversion rate of the X / Y proof mass, maximizes the utilization of the chip area, reduces chip size and cost, and reduces coupling errors and quadrature errors, thereby improving sensing accuracy.

An algorithm and architecture for sense transfer function estimation injects one or more test signals from a signal generator into a MEMS gyroscope to detect an output signal (e.g., proof mass output sense signal), including an in-phase (e.g., Coriolis) component and a quadrature component. The in-phase and quadrature components are encoded with reference signals to determine phase and / or gain variation and are processed via a variety of components (e.g., matrix rotation, digital gain, tones demodulator, transfer function errors estimation, etc.) to estimate a sense transfer function of the MEMS (e.g., Hs(fd)) and corresponding phase and / or gain offset of Hs(fd). The in-phase and quadrature components are also compensated for phase and / or gain offset by system components.

The invention discloses an accelerometer system, and the accelerometer system comprises a first magnetic assembly which comprises a first pole shoe; the second magnetic assembly comprises a second pole shoe, and the physical shape of the second pole shoe is different from that of the first pole shoe; and a proof mass assembly, the proof mass assembly comprising: a proof mass, the proof mass being between the first magnetic assembly and the second magnetic assembly. A first magnetic flux flows from the first magnetic assembly to the first pole shoe, wherein an amount of the first magnetic flux through the first coil is based on the physical shape of the first pole shoe; a second magnetic flux flows from the second magnetic assembly to the second pole shoe, and wherein a magnitude of the second magnetic flux is based on the physical shape of the second pole shoe.

A round robin MEMS sensor system includes multiple sensor types connected to a shared sense path in which measurement and evaluation operations are performed in a round robin fashion. Signals corresponding to movement of a proof mass are selectively provided to measurement circuitry, and in turn, the output of the measurement circuitry is selectively provided to the evaluation circuitry. The timing of these operations is optimized such that numerous MEMS sensor and other sensor outputs can be evaluated through the common sense path without sacrificing sensor accuracy or speed.

The application provides a free degree decoupling electrostatic accelerometer, belonging to the field of acceleration sensing test, comprising: a sensitive probe, a capacitive displacement sensing circuit, a feedback electrostatic actuator, a PID controller, a DAC circuit and a bias voltage driver; the surface of a proof mass is separated into several independent parts, the DAC circuit applies positive and negative amplitude analog bias voltage to the proof mass respectively; the bias voltage applied on the opposite surfaces of the proof mass is equal in size and opposite in sign; the capacitive displacement sensing circuit tests the position of the proof mass in the sensitive probe; the PID controller calculates a feedback voltage to control the capacitive plate; and the feedback electrostatic actuator applies the feedback voltage to the capacitive plate to generate a feedback force. The conventional electrostatic accelerometer needs to use a plus-minus combination circuit to obtain the free degree information, and the electrostatic accelerometer has the ability of free degree decoupling.

The utility model discloses a quartz flexible accelerometer with small -size swing piece, include: shell, two magnetic component and swing piece, mounting ring is set between the shell and swing piece, the electromagnetic board is set to the mounting ring outer wall, mounting frame is provided with two groups, all set in the swing piece eaves position department, and symmetrical design, correct component is provided with two, and respectively set in corresponding mounting frame inner wall, be used for the clamping fixed of swing piece on swing tongue, the utility model discloses due to adopt the design scheme of small -size swing piece structure, under the auxiliary action of mounting frame, when not using quartz flexible accelerometer, through torsional spring, lever, triangular block can fix swing tongue on swing piece, can effectively prevent swing tongue overhanging end droop, thereby can realize the efficacy of horizontal correction.

A gyroscope includes a substrate, a proof mass coupled to the substrate and configured to move in direction of an X axis and in direction of a Y axis orthogonal to the first axis, an X axis shuttle to selectively drive the proof mass along the X axis as a drive axis or sense movement of the proof mass along the X axis as a sense axis in response to the proof mass driven along the Y axis as the drive axis, and a Y axis shuttle to selectively sense movement of the proof mass along the Y axis as a sense axis in response to the proof mass driven along the X axis or drive the proof mass along the Y axis as the drive axis. The X axis shuttle is symmetric to the Y axis shuttle along a diagonal axis that is diagonal to both the X axis and the Y axis. The X and Y axis shuttles have gaps designed for a predetermined DC voltage to generate spring softening (negative cubic nonlinearity) that is equal to spring hardening (positive cubic nonlinearity), ensuring linear motion at high amplitudes (⅓ of the capacitive gap).

The present invention relates to coupling folded springs in a microelectromechanical system (MEMS) device. A MEMS device is described, comprising a proof mass movably connected to a substrate via folded springs disposed on opposite sides of the proof mass, wherein a coupler couples two of the folded springs together. In some embodiments, the coupler is a rod and can be rigid. Thus, the coupler constrains the relative motion of the folded springs. In this manner, the motion of the proof mass can be constrained to a preferred type and frequency.

Angular accelerometers are described, as are systems employing such accelerometers. The angular accelerometers may include a proof mass and rotational acceleration detection beams directed toward the center of the proof mass. The angular accelerometers may include sensing capabilities for angular acceleration about three orthogonal axes. The sensing regions for angular acceleration about one of the three axes may be positioned radially closer to the center of the proof mass than the sensing regions for angular acceleration about the other two axes. The proof mass may be connected to the substrate though one or more anchors.

The present disclosure relates to apparatuses, systems, and techniques for determining 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.

A microelectromechanical system (MEMS) accelerometer includes a proof mass that translates outside of a MEMS device plane in response to a force of interest such as a z-axis linear acceleration. The proof mass is a component of a suspended spring-mass system that is anchored to both a cover substrate layer and a base substrate layer by an anchoring system. The anchoring system includes a central anchor that is mechanically anchored to only the cover layer, while two adjacent anchors are located at opposite sides of the central anchor and are anchored to at least the base substrate and have an electrical connection to processing circuitry of the base substrate. Compliant springs connect the central anchor to the two adjacent anchors in a manner such that the anchoring system absorbs applied stresses such as shear forces applied during system packaging, assembly, and during use in an end product.

The present invention discloses a method for constructing a photocurrent model of an inertial sensor, including: establishing a photocurrent model based on the general equation of photocurrent on a metal surface and the geometric structure of the inertial sensor; respectively calibrating the parameters of the photocurrent model: obtaining the number of photoelectron emissions in each divided area of the inner surface of the inertial sensor according to the optical characteristics; regulating the potential difference between each electrode plate and the proof mass to make the state between the electrode plate and the proof mass in the saturation state and the zero state, and respectively measuring the photocurrent in these two mode combinations, and obtaining the shunt probability between all the electrode plates and the proof mass according to the photocurrent in the two mode combinations; measuring the photocurrent of the proof mass from the negative saturation state potential to the positive saturation state potential, and inversely solving the photoelectron migration probability of the inertial sensor from the photocurrent model equation. The present invention can accurately give the influence of the potential of each electrode plate in the inertial sensor on the discharge performance of the proof mass, and assist in designing the discharge strategy of the charge management system.

A dual axis accelerometer with a single proof mass measures in-plane acceleration (e.g., either along an x-axis or a y-axis), out-of-plane acceleration (e.g., normal to an x-y plane), and tilt of a fixed portion of a MEMS layer (e.g., normal to the x-y plane). In response to a tilt measurement, the dual-axis accelerometer compensates any offset (e.g., variability) of the out-of-plane accelerometer in order to maintain offset stability. In some embodiments, multiple dual axis accelerometers, perpendicularly configured, may be implemented via processing circuitry to offer three axis sensitivity capability.

The application is directed to a MEMS acousto-optic accelerometer for the detection and measurement of acceleration. The accelerometer is fabricated of optical quality materials using MEMS processing techniques on a substrate. It is comprised of a Bragg cell, proof mass, hinge, light source, and an optical detector. The proof mass of the accelerometer is attached to the substrate by a hinge that allows for pendulous motion under applied acceleration. The Bragg cell is anchored to the proof mass and to the substrate in such a way as to oppose the pendulous motion. The light source is coupled to the Bragg cell whose output is sensed by the optical detector. Force created by the proof mass and acceleration causes a change in the vibrational frequency of the Bragg cell resulting in a change in the frequency of the light sensed by the optical detector, which provides observability of the applied acceleration.

An accelerometer system includes a housing including a first portion and a second portion, the housing having a first coefficient of thermal expansion (CTE) value; and a proof mass element disposed between the first portion and the second portion of the housing, where a first surface of the proof mass element contacts the first portion and a second surface of the proof mass element contacts the second portion, the proof mass element having a second CTE value that differs from the first CTE value by within 30% of the first CTE value.

The present application belongs to the field of electrostatic accelerometers, and specifically discloses an electrostatic accelerometer and a zero position adjustment method thereof, the method comprising: when the external acceleration acting on the capacitor plate is an acceleration in a first direction, adjusting the control zero position of the test mass to a first position range; when the external acceleration acting on the capacitor plate is an acceleration in a second direction, adjusting the control zero position of the test mass to a second position range; wherein, the first position range is the position of the test mass when the distance of the test mass relative to the first capacitor plate is less than the distance of the test mass relative to the second capacitor plate, and the second position range is the position of the test mass when the distance of the test mass relative to the first capacitor plate is greater than the distance of the test mass relative to the second capacitor plate; the position of the test mass is the distance between the center of the test mass and the axis of symmetry of the two capacitor plates. Through this application, the present application effectively improves the range of the electrostatic accelerometer on the basis of the traditional electrostatic accelerometer.

This application belongs to the field of precision measurement, and specifically discloses a device and method for measuring the surface potential of a test mass based on a milligram-level torsion balance. Through this application, a milligram-level torsion balance is used instead of the traditional torsion balance. Compared with the traditional torsion balance, the milligram-level torsion balance has a smaller moment of inertia, lower torque-sensing thermal noise, and a torque detection level better than 10<supgt;‑18< / supgt> Nm / Hz<supgt;0.5< / supgt>, with extremely high detection sensitivity; a micrometer-level charged microsphere is used instead of the source conductor probe as the excitation source, and the spatial resolution can reach the micrometer level. Since the charged microsphere in suspension has a small charge amount and a small volume, the influence on the surface potential of the test mass to be measured is small and can be ignored, taking into account a relatively high spatial resolution; an optical module is used instead of the micro-displacement platform to provide the optical trap gradient force for the suspension of the charged microsphere and change the position of the suspended charged microsphere so that it faces different regions of the test mass surface. The suspended microsphere only interacts with photons, reducing the mechanical contact between the microsphere and other objects, reducing the friction effect, and improving the detection accuracy.

Provided are a fully-decoupled three-axis MEMS gyroscope and an electronic product. The gyroscope includes a substrate, an X / Y proof mass, Z proof masses, driving structures, and Z decoupled masses fixed to the substrate. The X / Y proof mass is annularly arranged outside the Z proof masses, the driving structures, and the Z decoupled masses; the X / Y proof masses are arranged oppositely along an x-axis direction; the driving structures are arranged oppositely along the x-axis direction outside the Z proof masses; and the Z decoupled masses are arranged oppositely along the x-axis direction at inner sides of the Z proof masses. The X / Y proof mass is elastically connected to the driving structures adjacent thereto, each Z proof mass is elastically connected to one driving structure adjacent thereto, and each Z decoupled mass is elastically connected to one Z proof mass adjacent thereto. The gyroscope has improved detection precision.

An accelerometer system including: a housing comprising a first portion and a second portion, the housing has a first coefficient of thermal expansion (CTE) value; and a proof mass element disposed between the first portion and the second portion of the housing, wherein a first surface of the proof mass element contacts the first portion and a second surface of the proof mass element contacts the second portion, the proof mass element having a second CTE value, the second CTE value being within 30% of the first CTE value.

A micro-electromechanical device of the inertial sensor type, includes a support, a movable frame, translationally guided along an axis of displacement parallel to the support, and including a proof mass which extends from a first end, connected to the support through a mechanical link, up to a second end, the mass being connected, on the side of the second end, to a member for detecting pivoting of the mass with respect to the frame. The link includes a thin, flexible wall which extends parallel to the support, from the frame to the first end of the proof mass, along a mean line which is parallel to the axis of displacement of the frame.

An accelerometer comprising a first proof mass and a second proof mass which are coupled to each other with a coupling structure which extends from the first proof mass to the second proof mass. The coupling structure synchronizes the movement of the first and second proof masses so that the first and second proof masses may be linearly displaced from their rest position in the x-direction, rotationally displaced in opposite in-plane directions and rotationally displaced in opposite out-of-plane directions.

A design calculation and use method of a retarder mass block assembly for indirectly measuring dynamic stiffness transmitted by a multi-type flexible pipe, wherein the retarder mass block assembly is designed according to basic parameters of the flexible pipe to be measured and a required effective test frequency range (f min , f max ), the upper and lower limits of the mass of the retarder mass block are determined, and the retarder mass block assembly and the retarder mass block unit are selected. The retarder mass block assembly mainly comprises the retarder mass block unit and connecting fasteners, the retarder mass block assembly is connected with the transition element, the flexible pipe to be measured and the excitation element by the connecting fasteners respectively, and axial measurement and transverse measurement of the indirectly measured dynamic stiffness are completed. By using combinations of different retarder mass block unit assemblies, the measurement requirements of dynamic stiffness transmitted by multi-type flexible pipes can be met without changing the overall structure of the measurement rack.

The invention provides a capacitance displacement sensing zero offset calibration and compensation method, which comprises the following steps of: adding a compensation signal and a calibration signal into a servo control system of electrostatic suspension capacitive inertial measurement equipment, and calibrating and compensating the capacitance displacement sensing zero offset in a closed-loop state. The method comprises the following steps: by utilizing a nonlinear effect caused by capacitance displacement sensing zero offset, actively applying a calibration signal modulated by a sine carrier trapezoidal wave to a test mass block, analyzing a quadratic term nonlinear response of an output signal of a measurement system controller, and calculating to obtain a capacitance displacement sensing zero offset value according to the nonlinear response; and a compensation signal corresponding to the zero-bias anti-phase value is directly applied to the input end of the system controller, so that the zero-bias compensation of the capacitance displacement sensor is realized. By using the method, the capacitance displacement sensing zero offset generated by a system full link can be calibrated and compensated in a closed-loop state.

The invention discloses a high-precision accelerometer based on a movable light source. Comprising an outer frame, a spring oscillator structure and an optical displacement detection structure. The periphery of the outer frame is wrapped with a shading shell which serves as an installation reference of other parts of the accelerometer, and interference of external environment light to the light detection process is reduced; the spring oscillator structure is composed of an inspection mass and a reed supporting structure, and the inspection mass is composed of a balancing weight and a light source, fixedly connected with the outer frame through the reed supporting structure and used for sensing external acceleration changes. The optical displacement detection structure comprises a light source, a fixed light shielding plate which is assembled on the upper half part of the outer frame and located above the light source, and a two-quadrant photoelectric detector located above the light shielding plate, and is used for sensing a light intensity change signal caused by external acceleration change and converting the light intensity change signal into an electric signal. A combined structure of the movable light source and the fixed light shielding plate is adopted, dynamic changes of emergent light are triggered by light source displacement, light intensity changes are captured through an optical detection technology, and high-precision measurement of the accelerometer is achieved.

This application belongs to the field of precision measurement, and specifically discloses a six-degree-of-freedom ground simulation test device and method for in-orbit release of a test mass. The test device includes: a vacuum unit for simulating the space vacuum environment; a secondary pendulum unit disposed inside the vacuum unit for realizing the six-degree-of-freedom movement of the test mass. The secondary pendulum unit includes a primary pendulum body suspended inside the vacuum unit, and a test mass is suspended at a lateral end of the primary pendulum body at its own suspension connection point, and a trimming mass is connected to the other lateral end; a locking and releasing unit disposed inside the vacuum unit for locking and releasing the test mass; and a detection unit for detecting the displacement and deflection of the test mass. The test device of this application can perform a six-degree-of-freedom ground simulation test for in-orbit release of the test mass.

MEMS sensors output data that may be susceptible to systematic bias that diminishes the accuracy of the data. This disclosure is directed to a method that compensates for this bias so that the output is more accurate and representative. Once a movement of the proof mass of the MEMS sensor outputs a specific characteristic signal, and that signal is identified, the signal is dynamically processed to eliminate and / or reduce the offset. Some applications may require fast settling times, high accuracy of offset removal, and robustness to vibrations and shocks. These requirements typically conflict with each other, meaning that the faster the offset removal, the lower its accuracy, and the sensor is more susceptible to errors due to vibration and shock. In order to tradeoff these requirements, the output of the MEMS sensor is filtered with some non-linear and / or time variant processing, followed by averaging the signal during a startup phase over a steadily increasing number of sampling periods. Once the startup phase is complete, the offset compensation signal is determined and removed from the initial output signal from the MEMS sensor. By utilizing the disclosed method, it is possible to maintain a high accuracy of offset estimation, a fast settling time, while also mitigating the effects of external perturbations (e.g., shocks, vibrations) on the system during the offset estimation process.

The present invention provides an accelerometer, comprising a base, a sensing unit provided on the base, and two anchor points for fixing the base. The sensing unit comprises: an outer coupling unit, the outer coupling unit is stacked on the base; seesaw structures, wherein two seesaw structures are provided and arranged on the inner side of the outer coupling unit, and the two seesaw structures are arranged symmetrically about the center; inner coupling units, wherein two inner coupling units are provided and arranged on the inner side of the outer coupling unit, and the two inner coupling units are arranged symmetrically about a line connecting the two anchor points; and proof masses, wherein the proof masses are fixed to the outer coupling unit and / or the inner coupling units. The accelerometer also comprises out-of-plane detection devices, wherein the out-of-plane detection devices are respectively arranged in a base area directly facing the outer coupling unit and a base area directly facing the inner coupling units. The accelerometer of the present invention can make all the displacements of out-of-plane detection capacitors become linear displacements, greatly improving the linearity of acceleration detection.

A proof mass of a MEMS sensor is located above one or more bump stops that extend in the direction of the proof mass from a base substrate, and that are intended to prevent high-impact collisions between the proof mass and base substrate such as when the sensor is dropped or experiences other substantial external forces. A portion of the proof mass located above the bump stop is patterned at the same time that the functional features of the MEMS layer such as springs and masses are fabricated. The patterning reduces stiction between the proof mass and the bump stop, allowing the MEMS sensor to resume operation promptly after an event that results in contact between the proof mass and the bump stop.

A MEMS device includes a substrate, a set of spring, and a proof mass suspended above and coupled to the substrate by the springs. Each spring includes a corresponding anchor on the substrate and a beam extending away from that anchor. Each beam has a fixed end that is coupled to the anchor by a first linkage at one end of the beam proximal to the anchor and a free end that is coupled to the proof mass by a second linkage at an end of the beam that is distal to the anchor. The anchors are arranged symmetrically around a center of the proof mass. The proof mass translates vertically with respect to the substrate and when a vertical displacement of the proof mass toward the substrate reaches a predefined value, the free end of each spring contacts the substrate and prevents the proof mass from contacting the substrate.