Chirp Microsystems Inc.

Invensense, Inc.

University of California

Other

Richard J Przybyla

David Horsley

Mitchell Herman Kline

Stefon Shelton

Andre Guedes

Meng-Hsiung Kiang

Bernhard Boser

Ofer Rozen

Fabian T Goericke

Ryan Young

Benjamin E Eovino

Hao-Yen Tang

Joe Youssef

Sebastien Riccardi

David A Horsley

Cristabel Yang

Benoît Lachal

An object detection system includes an ultrasonic sensor and an image sensor. The ultrasonic sensor transmits an ultrasonic signal into an environment of interest and makes an initial determination regarding a potential object in the environment of interest based on received reflections of the ultrasonic signal. Based on that initial determination, the image sensor and associated processing circuitry wake up and capture one or more images of the object within the environment of interest. Those images are analyzed such as by a classifier to determine the object status, which is then compared to the object status as determined by the ultrasonic sensor. Detection parameters of the ultrasonic sensor are updated if the object status as determined ultrasonic sensor does not match the determination of the imaging system.

Dynamic adaptation of ultrasonic detection parameters based on image classification

A device comprises a processor communicatively coupled with an ultrasonic sensor which is configured to repeatedly emit ultrasonic pulses during transmit periods which are interspersed with receive periods. Returned ultrasonic signals corresponding to the emitted ultrasonic pulses are received by the ultrasonic sensor during the receive periods. The processor is configured to direct the ultrasonic sensor to listen, during a listening window, for a potentially interfering ultrasonic signal from a second ultrasonic sensor. The listening window is prior to a transmit period of the transmit periods. In response to detecting the potentially interfering ultrasonic signal during the listening window, the processor is configured to adjust operation of the ultrasonic sensor to avoid an ultrasonic collision with the second ultrasonic sensor to facilitate coexistence of the ultrasonic sensor and the second ultrasonic sensor in an operating environment shared by the ultrasonic sensor and the second ultrasonic sensor.

Ultrasonic device coexistence

Systems and methods for ultrasonic liquid level sensing. A circuit causes an ultrasonic transducer to transmit a sequence of ultrasonic pulses and receive a sequence of reflected signals. Each reflected signal includes at least one first reflection associated with at least one non-moveable surface and at least one second reflection associated with a moveable surface. A digital controller, for each reflected signal: determines at least one of a magnitude and a variance of the respective signal to form at least one output signal, identifies, in the at least one output signal, at least one first pulse indicative of the at least one non-moveable surface and at least one second pulse indicative of the moveable surface, and determines a distance of the moveable surface relative to the at least one non-moveable surface based on the identified first and second pulses.

Ultrasonic liquid level sensing

An ultrasonic transducer device comprises a piezoelectric micromachined ultrasonic transducer (PMUT), a transmitter with first and second differential outputs, and a controller. The PMUT includes a membrane layer. A bottom electrode layer, comprising a first bottom electrode and a second bottom electrode, is disposed above the membrane layer. The piezoelectric layer is disposed above the bottom electrode layer. The top electrode layer is disposed above the piezoelectric layer and comprises a segmented center electrode disposed above a center of the membrane layer and a segmented outer electrode spaced apart from the segmented center electrode. The controller, responsive to the PMUT being placed in a transmit mode, is configured to couple the first and second segments of the bottom electrode layer with ground, couple the first output of the transmitter with the segments of the segmented center electrode, and couple the second output with the segments of the segmented outer electrode.

Piezoelectric micromachined transducer and device

An ultrasonic transducer device comprises a controller and a differential piezoelectric micromachined ultrasonic transducer with a membrane later, a bottom electrode layer, a piezoelectric layer, and a top electrode layer comprising a first electrode with a positive voltage to displacement coefficient and a second electrode with a negative voltage to displacement coefficient. During a first period, the controller electrically decouples a first output of a first driver from the first electrode, electrically decouples a second output of a second driver from the second electrode, and electrically couples the first and second electrodes to equalize charge between them. During a second period, the controller electrically decouples the first and second electrodes, electrically couples the first output with the first electrode, and electrically couples the second output with the second electrode; where waveforms on the first and second outputs during the second time period are out of phase with one another.

Transmitter charge sharing in a differential ultrasonic transducer

An ultrasonic transceiver system includes a transmitter block, a receiver block, a state machine, and a computing unit. The transmitter block contains circuitry configured to drive an ultrasound transducer. The receiver block contains circuitry configured to receive signals from the ultrasound transducer and convert the signals into digital data. The state machine is coupled to the transmitter and receiver blocks and contains circuitry configured to act as a controller for those blocks. The computing unit is coupled to the transmitter block, the receiver block, and the state machine and is configured to drive the transmitter block and process data received from the receiver block by executing instructions of a program. The program memory is coupled to the computing unit and is configured to store the program. The computing unit is configured to be reprogrammed with one or more additional programs stored in the program memory.

Programmable ultrasonic transceiver

Split electrode design for a transducer

A diaphragm for a piezoelectric micromachined ultrasonic transducer (PMUT) is presented having resonance frequency and bandwidth characteristics which are decoupled from one another into independent variables. Portions of at least the piezoelectric material layer and backside electrode layer are removed in a selected pattern to form structures, such as ribs, in the diaphragm which retains stiffness while reducing overall mass. The patterned structure can be formed by additive, or subtractive, fabrication processes.

Variable thickness diaphragm for a wideband robust piezoelectric micromachined ultrasonic transducer (PMUT)

A transducer includes first and second piezoelectric layers made of corresponding different first and second piezoelectric materials and three or more electrodes, implemented in two or more conductive electrode layers. The first piezoelectric layer is sandwiched between a first pair of electrodes and the second piezoelectric layer is sandwiched between a second pair of electrodes. The first and second pairs of electrodes contain no more than one electrode that is common to both pairs.

Micromachined ultrasound transducer using multiple piezoelectric materials

A method, system and computer readable medium for Ultrasound contact tracing comprising receiving one or more advertise messages determining a base station from the one or more advertise messages wherein the base station generates a broadcast order from at least the one or more advertise messages. A broadcast order is determined and an ultrasound message is sent according to the broadcast order. A detection period for ultrasound messages is initiated according to the broadcast order and a user may be notified of a detected ultrasound message.

Ultrasonic range sensing enables measured social contact

Time of flight between two or more ultrasonic transceivers is measured using known delays. First and second transceivers are duty cycled, each having a respective receive period that is less than a measurement period during which the transceivers are configured to receive transmissions. An ultrasonic trigger pulse is transmitted by the first transceiver. The second transceiver, upon receiving the trigger pulse, transmits an ultrasonic response pulse after a first predefined delay time that is known to the first transceiver and greater than the receive period of the second transceiver. Subsequently, the first transceiver receives the ultrasonic response pulse and determines a receive time. The first transceiver determines the distance between the first transceiver and the second transceiver from a speed of sound, an elapsed time between the time of transmission of the trigger pulse and the receive time, and the first predetermine delay time.

Ultrasonic beacon tracking

Methods and systems are disclosed for determining pose information for at least one of a transmitter and receiver, both of which comprise ultrasonic transducers. A relative position is determined between the transmitter and the receiver and an orientation for at least is also determined. After obtaining field of view data for at least one of the transmitter and receiver, a field of view between them is determined, based at least in part on the field of view data, the determined relative position and the determined orientation. The pose information is then determined by weighting measurements of an ultrasonic signal emitted by the transmitter and received by the receiver based at least in part on the determined field of view relationship.

Object-localization and tracking using ultrasonic pulses with reflection rejection

An ultrasonic transceiver system includes a transmitter block, a receiver block, a state machine, a computer unit. The transmitter block contains circuitry configured to drive an ultrasound transducer. The receiver block contains circuitry configured to receive signals from the ultrasound transducer and convert the signals into digital data. The state machine is coupled to the transmitter and receiver blocks and contains circuitry configured to act as a controller for those blocks. The computing unit is coupled to the transmitter block, the receiver block, and the state machine and is configured to drive the transmitter block and process data received from the receiver block by executing instructions of a program. The program memory is coupled to the computing unit and is configured to store the program. The computing unit is configured to be reprogrammed with one or more additional programs stored in the program memory.

A piezoelectric micromachined ultrasound transducer (PMUT) is disclosed. The device consists of a flexible membrane that is connected to a rigid substrate via flexures. The flexures are defined by slots etched through the perimeter of the membrane. These features release the stress present on the structural layers of the membrane, making it less sensitive to residual stress. The flexures are designed to act as torsion springs so that the membrane's vibration mode shape is highly curved in the piezoelectric actuation area, thereby increasing the electromechanical coupling.

Growing community of inventors

Emeryville, CA, United States of America

Richard J Przybyla