An ultrasonic sensor includes a sensor body, a cushion member, a retainer unit, and a drainage path. The sensor body includes an ultrasonic microphone and a microphone support unit which allows a protruding part of the ultrasonic microphone located at a distal end in an axial direction to protrude and supports the protruding part. The cushion member covers the protruding part. The retainer unit allows exposure of a portion of the cushion member that is located at the distal end in the axial direction, and a portion of the cushion member that is located at a proximal end in the axial direction is sandwiched between the retainer unit and an outer peripheral surface of the protruding part. The drainage path penetrates the retainer unit in a radial direction to allow water to be discharged out of the retainer unit from a gap between the retainer unit and the cushion member.

The object of this invention is to provide an ultrasonic transducer for a measuring device capable of widening a frequency band suitable for transmitting and receiving ultrasonic waves while reducing the manufacturing cost. The ultrasonic transducer for a measuring device includes a substantially disc-shaped base material that serves too as an acoustic-matching layer and substantially disc-shaped piezoelectric element that is joined to the base material. The piezoelectric element is formed with grooves extending in the planar direction so that they do not cross one another, and the plurality of strip-shaped vibration units are arranged through the grooves. The length of the vibration unit becomes shorter as the distance from the center of the piezoelectric element increases. Then, the piezoelectric element vibrates in the thickness direction in the first-frequency band and vibrates in the radial direction in the second-frequency band, which is lower than the first-frequency band.

The object of this invention is to provide an ultrasonic transducer for a measuring device capable of widening a frequency band suitable for transmitting and receiving ultrasonic waves while reducing the manufacturing cost. The ultrasonic transducer for a measuring device includes a substantially disc-shaped base material that serves too as an acoustic-matching layer and substantially disc-shaped piezoelectric element that is joined to the base material. The piezoelectric element is formed with grooves extending in the planar direction so that they do not cross one another, and the plurality of strip-shaped vibration units are arranged through the grooves. The length of the vibration unit becomes shorter as the distance from the center of the piezoelectric element increases. Then, the piezoelectric element vibrates in the thickness direction in the first-frequency band and vibrates in the radial direction in the second-frequency band, which is lower than the first-frequency band.

Systems and methods for presenting marine information are provided herein. A system includes an array of a plurality of sonar transducer elements associated with a watercraft and a display. The system causes presentation of a chart of a body of water, including a representation of the watercraft at a current location. The system also operates the array to cause transmission of sonar beams into the underwater environment and receives sonar return data from the array. The system further generates, based on the sonar return data, a two-dimensional live sonar image, determines a facing direction of the array, and causes presentation of the sonar image in the facing direction on the chart and relative to the representation of the watercraft. Accordingly, live sonar imagery is presented on the chart to visually provide a relationship between objects within the live sonar imagery and the real-world position of those objects.

An ultrasound sensor includes a frame, wherein the frame includes an outer perimeter, an inner perimeter, and a midsection, wherein the midsection extends across the inner perimeter. The sensor further includes two or more transducer elements, wherein the two or more transducer elements are located within the inner perimeter, and include one or more membranes that include a bottom portion that includes a first piezoelectric layer and second piezoelectric layer, wherein the two or more transducer elements are each separated from the midsection, wherein the two or more transducer elements are configured to each activate a transmit mode and receive mode, wherein the transmit mode is configured to transmit a signal and the receive mode is configured to receive a signal, wherein a first transducer element activates the transmit mode when a second transducer element does not activate the transmit mode.

An ultrasound sensor includes a frame, wherein the frame includes an outer perimeter, an inner perimeter, and a midsection, wherein the midsection extends across the inner perimeter. The sensor further includes two or more transducer elements, wherein the two or more transducer elements are located within the inner perimeter, and include one or more membranes that include a bottom portion that includes a first piezoelectric layer and second piezoelectric layer, wherein the two or more transducer elements are each separated from the midsection, wherein the two or more transducer elements are configured to each activate a transmit mode and receive mode, wherein the transmit mode is configured to transmit a signal and the receive mode is configured to receive a signal, wherein a first transducer element activates the transmit mode when a second transducer element does not activate the transmit mode.

A method of operating a PMUT electro-acoustical transducer, the method comprising: applying over an excitation interval to the transducer an excitation signal which is configured to emit corresponding ultrasound pulses towards a surrounding space, acquiring at a receiver reflected ultrasound pulses as reflected in said surrounding space, generating a reference echo signal, performing a cross-correlation of said acquired received ultrasound pulses with said reference echo signal, performing a measurement based on the cross-correlation results, in particular a measurement of the time of flight of the ultrasound pulses, wherein said reference echo is obtained by finding an oscillation frequency of the transmitter on the basis of a transmitter ringdown signal, finding an oscillation frequency of the receiver on the basis of a receiver ringdown signal, performing a frequency tuning respectively on the transmitter and the receiver on the basis of said respective oscillation frequencies, then sweeping an input frequency of the transmitter to find a frequency of the maximum displacement in the ringdown signal, performing a frequency tuning of the receiver at said frequency of the maximum displacement in the ringdown signal of the transmitter.

Methods, apparatus, systems and articles of manufacture to detect changes in a physical environment are disclosed. An example apparatus includes a descriptor generator to generate a first descriptor, the descriptor generator including: a chirp producer to emit a chirp into the environment, a chirp recorder to record a response to the chirp from the environment, and a chirp response encoder to generate an encoding of the response to the chirp; a descriptor similarity generator to generate a similarity value, the similarity value to compare the first descriptor to a second descriptor; and a physical change indicator to, in response to the similarity value exceeding a similarity threshold, indicate that a physical change has occurred in the environment.

An ultrasonic transducer includes a transducer case and an ultrasonic element. The transducer case is formed into a bottomed, cylindrical shape having a side plate portion and a bottom plate portion that seals one end side of the side plate portion in an axial direction to configure a diaphragm. The ultrasonic element is fixedly supported to the bottom plate portion to face an interior space surrounded by the side plate portion and the bottom plate portion. The ultrasonic element is arranged in a position being offset in an in-plane direction orthogonal to the axial direction relative to a center position of the diaphragm in the in-plane direction to be capable of generating a first transmission wave having first directivity characteristics and a second transmission wave having second directivity characteristics that are directivity characteristics differing from the first directivity characteristics and in which sound pressure in the axial direction is decreased.

An ultrasonic transducer includes a transducer case and an ultrasonic element. The transducer case is formed into a bottomed, cylindrical shape having a side plate portion and a bottom plate portion that seals one end side of the side plate portion in an axial direction to configure a diaphragm. The ultrasonic element is fixedly supported to the bottom plate portion to face an interior space surrounded by the side plate portion and the bottom plate portion. The ultrasonic element is arranged in a position being offset in an in-plane direction orthogonal to the axial direction relative to a center position of the diaphragm in the in-plane direction to be capable of generating a first transmission wave having first directivity characteristics and a second transmission wave having second directivity characteristics that are directivity characteristics differing from the first directivity characteristics and in which sound pressure in the axial direction is decreased.