Lumedyne Technologies, Inc.

USA As Represented by Secretary of the Navy

Google Inc.

Mark Steven Fralick

Richard Lee Waters

John David Jacobs

Charles Harold Tally, Iv

Xiaojun Huang

Brad Wesley Chisum

Yanting Zhang

Hugo F Jazo

Brian B Dick

Jacques Pierre Leveille

Maxwell Mayekawa Kerber

Ricardo E Dao

David Carbonari

Jeffrey Alan Brayshaw

Max Kerber

Brian Chen

The present disclosure provides for using multiple inertial measurement units (IMUs) to recognize particular user activity, such as particular types of exercises and repetitions of such exercises. The IMUs may be located in consumer products, such as smartwatches and earbuds. Each IMU may include an accelerometer and a gyroscope, each with three axes of measurement, for a total of 12 raw measurement streams. A training image includes a plurality of subplots or tiles, each depicting a separate data stream. The training image is then used to train a machine learning model to recognize IMU data as corresponding to a particular type of exercise.

System and method for exercise type recognition using wearables

Systems and methods are described herein for extracting inertial information from nonlinear periodic signals. A system for determining an inertial parameter can include circuitry configured for receiving a first periodic analog signal from a first sensor that is responsive to motion of a proof mass, converting the first periodic analog signal to a first periodic digital signal, determining a result of trigonometrically inverting a quantity, the quantity based on the first periodic digital signal, and determining the inertial parameter based on the result.

Extracting inertial information from nonlinear periodic signals

Systems and methods are described herein for extracting inertial information from nonlinear periodic signals. A system for determining an inertial parameter can include circuitry configured for receiving first and second analog signals from first and second sensors, each sensor responsive to motion of a proof mass. The system can include circuitry configured for determining a difference between the first and second analog signals, determining a plurality of timestamps corresponding to times at which the difference crosses a threshold, and determining a plurality of time intervals based on the timestamp. The system can include circuitry configured for determining a result of applying a trigonometric function to a quantity, the quantity based on the plurality of time intervals and determining the inertial parameter based on the result.

Systems and methods are disclosed herein for extracting system parameters from nonlinear periodic signals from sensors. A sensor such as an inertial device includes a first structure and a second structure that is springedly coupled to the first structure. The sensor is configured to generate an output voltage based on a current between the first and second structures. Monotonic motion of the second structure relative to the first structure causes a reversal in direction of the current.

Systems and methods for extracting system parameters from nonlinear periodic signals from sensors

Systems and methods are disclosed herein for determining rotation. A gyroscope includes a drive frame and a base, the drive frame springedly coupled to the base. The gyroscope includes a drive structure configured for causing a drive frame to oscillate along a first axis. The gyroscope includes a sense mass springedly coupled to the drive frame. The gyroscope includes a sense mass sense structure configured for measuring a displacement of the sense mass along a second axis orthogonal to the first axis. The gyroscope includes measurement circuitry configured for determining a velocity of the drive frame, extracting a Coriolis component from the measured displacement, and determining, based on the determined velocity and extracted Coriolis component, a rotation rate of the gyroscope.

Systems and methods for controlling oscillation of a gyroscope

Systems and methods for determining rotation from nonlinear periodic signals

A time domain switching analog-to-digital converter apparatus and methods of utilizing the same. In one implementation, the converter apparatus comprises a carrier signal source, and at least one reference source. The carrier signal is summed with the input signal and the summed modulated signal is fed to a comparator circuit. The comparator is configured detects crossings of the reference level by the modulated waveform thereby generating trigger events. The time period between consecutive trigger events is used to obtain modulated signal deviation due to the input signal thus enabling input signal measurement. Control of the carrier oscillation amplitude and frequency enables real time adjustment of the converter dynamic range and resolution. The use of additional reference signal levels increases sensor frequency response and accuracy. A dual channel converter apparatus enables estimation and removal of common mode noise, thereby improving signal conversion accuracy.

Time domain switched analog-to-digital converter apparatus and methods

A rotational energy harvesting apparatus includes a rotor of magnets and a ring of linear-based kinetic energy harvesters. The rotor of magnets is fixed to a rotational source and is caused to sweep past the linear-based kinetic energy harvesters. The rotating magnets compel kinetic energy to be induced in the linear-based kinetic energy harvesters. The kinetic energy is converted into electrical energy.

Harvesting rotational energy using linear-based energy harvesters

A geophone including a plurality of ferromagnetic masses (e.g., magnets) disposed to oscillate on one or more compliant elements (e.g., springs) in a manner that produces a steep flux gradient at one or more conductive coils is disclosed. The magnetic masses are positioned with like poles facing each other so as to compress the magnetic field gradient. The coils may be positioned in the flux gap either between the magnets, in close proximity to the magnets, or surrounding the magnets. Vibration measurements may then be detected from the movement of at least one of the magnetic masses.

High sensitivity geophone

A method for analyzing an optical signal comprising: directing the optical signal into a scanning spectrometer system comprising a variable-wavelength filter and a detector; continuously modulating the variable-wavelength filter at a given modulation frequency to produce a time-based waveform; measuring the time-based waveform with the detector; converting the time-based waveform into a frequency spectrum comprising harmonics of the modulation frequency; and comparing the harmonics of the modulation frequency to premeasured harmonic spectra in a reference database.

Scanning spectroscopy modulation for frequency domain spectral analysis

An energy harvester comprising: a substrate; two magnets coupled to the substrate in close proximity to each other with like magnetic poles facing each other creating a flux gap; a coil coupled to the substrate and disposed within the flux gap, wherein the coil and the magnets are coupled to the substrate such that substrate acceleration causes relative elastic motion between the magnets and the coil thereby exposing the coil to a changing magnetic flux; and a resonant frequency tuner coupled to the substrate and configured to adjust the resonant frequency between the coil and the magnets.

Tunable resonant frequency kinetic energy harvester

An energy harvesting apparatus comprising: a substrate; two magnets coupled to the substrate in close proximity to each other with like magnetic poles facing each other creating a flux gap; a coil coupled to the substrate and disposed within the flux gap, wherein the coil and the magnets are coupled to the substrate such that substrate acceleration causes relative motion between the magnets and the coil thereby exposing the coil to a changing magnetic flux.

Electro-magnetic kinetic energy harvesting device using increased magnetic edge area

A method includes passing a portion of an optical signal through an aperture of a sensor having a sensing element, wherein the portion of the optical signal that passes through the aperture is an inner portion of the optical signal and the portion of the optical signal that does not pass through the aperture is an outer portion of the optical signal; producing a sensed signal by sensing the outer portion of the optical signal with the sensing element; and controlling the source of the optical signal using the sensed signal. A system for implementing the method includes an optical energy source and a sensor having an optical sensing portion and an aperture therein. The system may also include an optical isolator, a detection element, and a controller for controlling the optical energy source. The system may be used within a MEMS-based system.

Growing community of inventors

San Diego, CA, United States of America

Mark Steven Fralick