Milli Sensor Systems+actuators

Other

The Charles Stark Draper Laboratory, Inc.

Milli Sensors Systems & Actuators, Inc.

Milli Sensory Systems and Actuators, Inc.

Milli Sensor and Actuator Systems, Inc.

Kionix, Inc.

Donato Cardarelli

Michele S Sapuppo

Charles R Dauwalter

Paul Greiff

Scott G Adams

Joseph D Coccoli

Joseph G Walsh

Raymond Carroll

John R Stemniski

Frederick J Petri

Mark D Fontanella

Thomas E Reed

James Groves

A human-portable MEMS azimuth sensing unit and method that determines the azimuth of a target. There is a spinning support structure, with at least a gyroscope carried by the support structure. The gyroscope has an input axis and an output signal. There is an angle resolver that measures the spin angle of the support structure relative to a reference direction and that has an output signal. Circuitry determines the target azimuth based on the phase difference between the output signals of the gyroscope and the angle resolver. The phase difference can be based on the time between zero crossings of the sinusoidal gyro and angle resolver signals. An accelerometer can also be carried by the support structure, in which case its output can be used to level the unit.

Human-portable MEMS Azimuth sensing unit and method

A system and method for separating bias instability of MEMS inertial instruments such as gyroscopes or accelerometers from the instrument signal, in which the inertial measurement instrument has an input axis and an output signal, and the bias instability has a frequency. The instrument is rotated about a rotation axis that is orthogonal to the input axis, at a frequency that is greater than the bias instability frequency. The instrument output signal is detected, and demodulated with a phase-sensitive detection method referenced to the instrument rotation.

Bias measurement for MEMS gyroscopes and accelerometers

An inertial measurement unit (IMU) for a spinning aerial vehicle that spins about a spin axis having a substrate defining a plane, the substrate fixed to the vehicle with the plane essentially orthogonal to the spin axis so that the substrate spins about the spin axis as the vehicle does, at least one generally planar gyroscope coupled to the substrate, the gyroscope defining a gyro input axis that is essentially parallel to the plane and generating a gyro output signal, at least one generally planar accelerometer coupled to the substrate, the accelerometer defining an accelerometer input axis that is essentially parallel to the plane and generating an accelerometer output signal, and a system for demodulating the gyro output signal with a phase-sensitive demodulation referenced to the accelerometer output signal. Also featured is a method of providing guidance information for a spinning aerial vehicle that spins about a spin axis using the described system.

Inertial measurement unit for spin-stabilized aerial vehicles, and method of providing guidance information using same

A planar MEMS accelerometer that detects acceleration along an input axis that is orthogonal to the plane. There are spaced bonding pads coupled to a substrate. A generally planar Servo Member (SM) is flexibly coupled to the bonding pads by servo member flexures such that the SM is capable of oscillatory motion about a servo axis that is orthogonal to the plane. A generally planar plate Torque Summing Member (TSM) is located within, coplanar with, and flexibly coupled to the SM such that the TSM is capable of rotational motion about an output axis that is in the plane and orthogonal to the servo axis. The TSM is mass-imbalanced relative to the output axis. A generally planar plate rotor is located within, coplanar with, and flexibly coupled to the TSM such that it is capable of rotary oscillatory motion relative to the TSM about a rotor axis that is in the plane. Rotor drives directly oscillate the rotor about the rotor axis at a rotor oscillation frequency and amplitude. SM drives oscillate the SM about the servo axis at a SM oscillation frequency and amplitude, and thereby also oscillate the rotor and TSM about the servo axis at the SM oscillation frequency. Motion sensors detect oscillation of the rotor and the SM. TSM motion sensors detect rotation of the TSM relative to the substrate about the output axis.

GRA MEMS accelerometer

A gyroscope that lies generally in a plane, for detecting rotation rate about a gyro input axis. The gyroscope has a substrate, and a generally planar outer member flexibly coupled to the substrate such that it is capable of oscillatory motion about a drive axis that is orthogonal to the input axis. There is also a generally planar inner member coplanar with and flexibly coupled to the outer member such that it is capable of rotary oscillatory motion relative to the outer member about an output axis that is orthogonal to the plane of the members. There are one or more drives for directly or indirectly oscillating the outer member about the drive axis, and one or more sensors that detect oscillation of the inner member about the output axis.

MEMS gyroscope with output oscillation about the normal to the plane

An inertial instrument such as an accelerometer or gyroscope having scale factor functionality, and that lies generally in a plane. The gyro detects rotation rate about a gyro input axis. The gyroscope has a substrate, a generally planar scale factor gimbal flexibly coupled to the substrate such that it is capable of oscillatory motion about the input axis, a generally planar support member coplanar with and flexibly coupled to the scale factor gimbal such that the support member is capable of oscillatory motion about a drive axis that is orthogonal to the input axis, and a generally planar gyro member coplanar with and flexibly coupled to the support member such that it is capable of rotary oscillatory motion relative to the support member about an output axis that is orthogonal to the plane of the members. There are one or more first drives for oscillating the support member about the drive axis, and one or more second drives for oscillating the scale factor gimbal about the input axis. One or more gyro output sensors that detect oscillation of the gyro member about an output axis that is orthogonal to both the input axis and the drive axis.

Scale factor measurement for mems gyroscopes and accelerometers

A gyroscope for detecting rotation about a gyro input axis, having a support structure, at least one mass flexibly coupled to the support structure such that it is capable of motion in two directions along a drive axis, the mass offset from the gyro output axis, one or more drives for oscillating the flexibly-coupled masses along the drive axis, one or more mass motion sensors that sense motion of the flexibly-coupled masses along their drive axes, and one or more gyro output sensors that detect rotation of the support structure about the output axis.

Tuning fork gyroscope

A system and method for separating bias instability of MEMS inertial instruments such as gyroscopes or accelerometers from the instrument signal, in which the inertial measurement instrument has an input axis and an output signal, and the bias instability has a frequency. The instrument is oscillated about an oscillation axis that is orthogonal to the input axis, at a frequency that is greater than the bias instability frequency. The instrument output signal is detected, and demodulated with a phase-sensitive detection method referenced to the instrument rotation.

Small angle bias measurement mechanism for MEMS instruments

An accelerometer that lies generally in a plane, for detecting acceleration along an input axis. There is a substrate, a generally planar Servo Member (SM) flexibly coupled to the substrate such that it is capable of oscillatory motion about a servo axis that lies in the plane, a generally planar Torque Summing Member (TSM) coplanar with and flexibly coupled to the SM such that the TSM is capable of rotary motion relative to the SM about an output axis that is in the plane and orthogonal to the servo axis, wherein the TSM is mass-imbalanced relative to the output axis, and a generally planar rotor coplanar with and flexibly coupled to the TSM such that it is capable of rotary oscillatory motion relative to the TSM about a rotor axis that is orthogonal to the plane of the members. There are drives for oscillating the rotor about the rotor axis and for oscillating the SM about the servo axis. Output sensors detect oscillation of the rotor about the rotor axis and of the SM about the servo axis. Output sensors detect rotation of the TSM about the output axis.

A gyroscope that lies generally in a plane, for detecting rotation rate about a gyro input axis. The gyroscope has a substrate, and a generally planar support member flexibly coupled to the substrate such that it is capable of oscillatory motion about a drive axis that is orthogonal to the input axis. There is also a generally planar gyro member coplanar with and flexibly coupled to the support member such that it is capable of rotary oscillatory motion relative to the support member about an output axis that is orthogonal to the plane of the members. There are one or more drives for directly or indirectly oscillating the gyro member about the drive axis, and one or more gyro output sensors that detect oscillation of the gyro member about the output axis.

G2-Gyroscope: MEMS gyroscope with output oscillation about the normal to the plane

Three magnetic substrates are provided, the first substrate forms the rotor and the other two form the outer stator. A series of spaced concentric grooves and spaced spiral grooves are formed in the central region of both faces of the first substrate. A hole is placed at the center of the spiral grooves, and filled with magnetic material. A conductor is then deposited into the spiral grooves, forming a central wheel. A series of spaced serpentine grooves and generally radial grooves are formed on each active face of the other two substrates. A conductor is then deposited into the serpentine grooves, and a magnetic material is deposited into the generally radial grooves. The two outer substrates are then bonded against the first substrate such that the outer end of each magnetic path overlays a filled hole in the first substrate, creating the stator of an axial air gap reluctance motor.

Method of fabricating a rate gyroscope and accelerometer multisensor

This invention relates to the fabrication of planar inductive components whereby the design in cross-section describes a conductor surrounded by magnetic material along the length of the conductor; an electrical insulator is placed between the conductor and the magnetic material. Cases also apply where more than one independent conductor is used. The planar form allows integration of inductive components with integrated circuits. These inductive components can be embedded in other materials. They can also be fabricated directly onto parts.

Fabrication approaches for the formation of planar inductors and transformers

Inertial Measurement Units based on integrated designs to reduce alignment and assembly costs. Integration also leads to performance improvement, increased miniaturization and simplification as well as reduced cost. Also disclosed are gyroscopes and accelerometers that are identical, yet by their mechanization, can be made to act as separate sensors. Miniaturization and simplification is improved by combining instruments that can share a common member. Savings in space and complexity are also possible in the electronics when elements are shared.

Planar inertial measurement units based on gyros and accelerometers with a common structure

MEMS-Integrated IMUs are possible based on a common substrate that provides a common oscillatory drive for the operation of the gyroscopes and accelerometers. The common substrate becomes the stable member utilized in conventional IMUs. The advantages of the embodiments are smallest size, flexibility in how IMUs are configured, reduced electronics and a single package. MEMS integration also reduces uncertainties due to separately developed instruments based on different fabrication processes, materials, assembly and alignment.

MEMS-integrated inertial measurement units on a common substrate

An oscillatory gyroscope is described with decoupled drive and sense oscillators and reduced cross-axis sensitivity. The gyroscope is fabricated using a plasma micromachining process on standard silicon wafers. The electrical isolation of the drive and sense functions of the gyroscope, contained within the same micromechanical element, reduce cross-coupling while obtaining high inertial mass and high sensitivity.

Growing community of inventors

Medfield, MA, United States of America

Donato Cardarelli