Abstract: A system having at least a first component and a second component positioned at different locations on a user's body (e.g., on the user's head and held on the user's hand). Each component includes at least one inertial measurement unit (IMU) configured generate measurements indicating acceleration and angular rate data. The generated measurements of the IMUs are used with ground truth information indicating the positions of the first and second component to generate a set of training data to train a neural network configured to predict a relative position between the first and second components based on IMU measurements received over a predetermined time period. Because the neural network is trained based upon movements of a human user, the neural network model takes into account physiological constraints of the user in determining how the set of potential positions of the different components may change over time, reducing potential error.

Abstract: The subject disclosure provides exemplary 3-axis (e.g., GX, GY, and GZ) linear and angular momentum balanced vibratory rate gyroscope architectures with fully-coupled sense modes. Embodiments can employ balanced drive and/or balanced sense components to reduce induced vibrations and/or part to part coupling. Embodiments can comprise two inner frame gyroscopes for GY sense mode and an outer frame or saddle gyroscope for GX sense mode and drive system coupling, drive shuttles coupled to the two inner frame gyroscopes or outer frame gyroscope, and four GZ proof masses coupled to the inner frame gyroscopes for GZ sense mode. Components can be removed from an exemplary overall architecture to fabricate a single axis or two axis gyroscope and/or can be configured such that a number of proof-masses can be reduced in half from an exemplary overall architecture to fabricate a half-gyroscope. Other embodiments can employ a stress isolation frame to reduce package induced stress.

Abstract: In a first aspect, the angular rate sensor comprises a substrate and a rotating structure anchored to the substrate. The angular rate sensor also includes a drive mass anchored to the substrate and an element coupling the drive mass and the rotating structure. The angular rate sensor further includes an actuator for driving the drive mass into oscillation along a first axis in plane to the substrate and for driving the rotating structure into rotational oscillation around a second axis normal to the substrate; a first transducer to sense the motion of the rotating structure in response to a Coriolis force in a sense mode; and a second transducer to sense the motion of the sensor during a drive mode. In a second aspect the angular rate sensor comprises a substrate and two shear masses which are parallel to the substrate and anchored to the substrate via flexible elements. In further embodiments, a dynamically balanced 3-axis gyroscope architecture is provided.

Abstract: A dynamically balanced 3-axis gyroscope architecture is provided. Various embodiments described herein can facilitate providing linear and angular momentum balanced 3-axis gyroscope architectures for better offset stability, vibration rejection, and lower part-to-part coupling.

Abstract: A device is provided, including a frame that supports two eyepieces, a capacitive sensor mounted on the frame, an inertial measurement unit mounted on the frame, and a circuit component inside the frame, wherein the circuit component electrically couples the capacitive sensor and the inertial measurement unit with a processor and a memory inside the frame. A method for using the above device is also provided.

Abstract: A device is provided, including a frame, providing mechanical support to at least two eyepieces, a capacitive sensor mounted on the frame, an inertial measurement sensor mounted on the frame, and a flexible circuit component inside the frame and electrically coupling the capacitive sensor and the inertial measurement sensor with a processor circuit and a memory circuit inside the frame. A method for using the above device is also provided.

Abstract: A MEMS device may output a signal during operation that may include an in-phase component and a quadrature component. An external signal having a phase that corresponds to the quadrature component may be applied to the MEMS device, such that the MEMS device outputs a signal having a modified in-phase component and a modified quadrature component. A phase error for the MEMS device may be determined based on the modified in-phase component and the modified quadrature component.

Abstract: 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.

Abstract: A headset comprise a frame and a vibration sensor coupled to the frame. The vibration sensor may be located in a nosepad of the frame, and configured to measure tissue vibrations of a user when the headset of worn by the user. A controller receives a signal corresponding to the measured vibration data from the vibration sensor, and analyzes the received signal to infer a sequence of states of the received signal, such as a sequence of respiratory states. The controller further determines a value of a health metric based upon the inferred sequence of states, e.g., a respiratory rate of the user, and performs an action using the determined value of the health metric.

Abstract: A depth sensing system is configured to track one or both eyes of a user. The depth sensing system includes a transducer chip comprising a phased array of ultrasound transducers that transmit a signal at an eye of the user and detect a reflected signal from the eye. A controller estimates an orientation of the eye based on the reflected signals received by the phased array. The depth sensing system may be part of a headset that includes a display element configured to display content to a user wearing the headset.

Abstract: An actuator aligned multi-channel projector assembly generates image light using a plurality of projectors. A projector includes a plurality of optical components in optical series and one or more actuators. The plurality of optical components include a light source and a plurality of optical elements. The light source generates first light. The plurality of optical elements project the first light. The first light is output from the projector and combined with a second to form an image presented via a display element of a headset to a user. The one or more actuators adjust a position of at least one optical component of the plurality of optical components relative to another optical component in order to compensate for misalignment of a portion of the image formed from the first light relative to a portion of the image formed from the second light.

Abstract: A MEMS device may output a signal during operation that may include an in-phase component and a quadrature component. An external signal having a phase that corresponds to the quadrature component may be applied to the MEMS device, such that the MEMS device outputs a signal having a modified in-phase component and a modified quadrature component. A phase error for the MEMS device may be determined based on the modified in-phase component and the modified quadrature component.

Abstract: A depth sensing system is configured to track one or both eyes of a user. The depth sensing system includes a transducer chip comprising a phased array of ultrasound transducers that transmit a signal at an eye of the user and detect a reflected signal from the eye. A controller estimates an orientation of the eye based on the reflected signals received by the phased array. The depth sensing system may be part of a headset that includes a display element configured to display content to a user wearing the headset.

Abstract: A system having at least a first component and a second component positioned at different locations on a user's body (e.g., on the user's head and held on the user's hand). Each component includes at least one inertial measurement unit (IMU) configured generate measurements indicating acceleration and angular rate data. The generated measurements of the IMUs are used with ground truth information indicating the positions of the first and second component to generate a set of training data to train a neural network configured to predict a relative position between the first and second components based on IMU measurements received over a predetermined time period. Because the neural network is trained based upon movements of a human user, the neural network model takes into account physiological constraints of the user in determining how the set of potential positions of the different components may change over time, reducing potential error.

Abstract: A MEMS device may output a signal during operation that may include an in-phase component and a quadrature component. An external signal having a phase that corresponds to the quadrature component may be applied to the MEMS device, such that the MEMS device outputs a signal having a modified in-phase component and a modified quadrature component. A phase error for the MEMS device may be determined based on the modified in-phase component and the modified quadrature component.

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: Described herein are accelerometers, apparatus and systems incorporating accelerometers, and techniques for controlling sensing operations in an accelerometer. In certain embodiments, an accelerometer is a microelectromechanical systems (MEMS) device including a proof mass, an anchor, a spring between the proof mass and the anchor, a drive electrode, and a sense beam. The anchor is located in an opening defined by a body of the proof mass. The spring and the proof mass form a spring system suspended from the anchor. The sense beam is configured to oscillate at a particular resonance frequency that changes according to a force generated by movement of the proof mass in response to acceleration. In some embodiments, a support structure couples the anchor to the spring and operates as a stress decoupling area that prevents or limits propagation of stress from the anchor to the sense beam and the spring system.

Abstract: The subject disclosure provides exemplary 3-axis (e.g., GX, GY, and GZ) linear and angular momentum balanced vibratory rate gyroscope architectures with fully-coupled sense modes. Embodiments can employ balanced drive and/or balanced sense components to reduce induced vibrations and/or part to part coupling. Embodiments can comprise two inner frame gyroscopes for GY sense mode and an outer frame or saddle gyroscope for GX sense mode and drive system coupling, drive shuttles coupled to the two inner frame gyroscopes or outer frame gyroscope, and four GZ proof masses coupled to the inner frame gyroscopes for GZ sense mode. Components can be removed from an exemplary overall architecture to fabricate a single axis or two axis gyroscope and/or can be configured such that a number of proof-masses can be reduced in half from an exemplary overall architecture to fabricate a half-gyroscope. Other embodiments can employ a stress isolation frame to reduce package induced stress.

Abstract: The subject disclosure provides exemplary 3-axis (e.g., GX, GY, and GZ) linear and angular momentum balanced vibratory rate gyroscope architectures with fully-coupled sense modes. Embodiments can employ balanced drive and/or balanced sense components to reduce induced vibrations and/or part to part coupling. Embodiments can comprise two inner frame gyroscopes for GY sense mode and an outer frame or saddle gyroscope for GX sense mode and drive system coupling, drive shuttles coupled to the two inner frame gyroscopes or outer frame gyroscope, and four GZ proof masses coupled to the inner frame gyroscopes for GZ sense mode. Components can be removed from an exemplary overall architecture to fabricate a single axis or two axis gyroscope and/or can be configured such that a number of proof-masses can be reduced in half from an exemplary overall architecture to fabricate a half-gyroscope. Other embodiments can employ a stress isolation frame to reduce package induced stress.

Abstract: Microelectromechanical systems (MEMS) gyroscopes and related measurement and calibration techniques are described. Various embodiments facilitate phase estimation of an ideal phase for a demodulator mixer associated with an exemplary MEMS gyroscope using quadrature tuning, which can improve offset performance over life time for exemplary MEMS gyroscopes. Exemplary embodiments can comprise adjusting a quadrature component of an exemplary MEMS gyroscope sense signal, measuring a change in offset of the exemplary MEMS gyroscope at an output of a demodulator mixer associated with the exemplary MEMS gyroscope, estimating a phase error between the quadrature component and a demodulation phase angle of the demodulator mixer based on the change in the offset, and periodically adjusting the demodulation phase angle of the demodulator mixer based on the phase error.