An object detection device comprises a transmission sound pressure adjustment unit adjusting a sound pressure of the search wave so that the sound pressure of the search wave or a reflected wave based on the search wave is within a predetermined transmission target range. The transmission unit transmits, as the search wave, a first search wave with a first frequency changing with time at a first rate and a second search wave with a second frequency changing with time at a second rate that is different from the first rate. The transmission sound pressure adjustment unit is configured to adjust the sound pressure of each of the first and second search waves so that the sound pressure of the corresponding one of the first and second search waves or the reflected wave based on the corresponding one of the first and second search waves is within the transmission target range.

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 ultrasound transducer of a vehicle system, comprising a membrane configured to vibrate to generate an ultrasound when voltage is applied and further configured to vibrate in an out-of-plane movement, wherein the membrane includes a first piezoelectric film at a center of the membrane, a supporting member including a second piezoelectric film, the supporting member supporting and surrounding the membrane, wherein in response to a translation of motion or actuation from the membrane, the supporting member mode does not move when there is the out-of-plane movement from the membrane.

An ultrasound transducer of a vehicle system includes a support member that attaches to and connects to the bottom portion of a membrane of the ultrasound transducer and supports the membrane, wherein the support member includes one or more cantilevers with a first end attaching to the membrane and a second end attaching to a support portion of the support member that attaches to the substrate, wherein the cantilever extends across and floats above the substrate, wherein the first end of the cantilever includes a stub extending away from a surface of the cantilever, wherein the stub extends away from the surface without contacting the substrate, wherein the one or more cantilevers includes one or more piezoelectric layers on the surface of the cantilever.

Ultrasonic audio processing circuitry and a method useful in ultrasonic presence detection. An ultrasonic burst generator produces an ultrasonic burst signal at one or more ultrasonic frequencies, and an equalizer equalizes that ultrasonic burst signal according to frequency response characteristics of the speaker and microphone at those ultrasonic frequencies. Driver circuitry drives a speaker with the ultrasonic burst signal, which may be combined with an audible audio signal. An ultrasonic separation filter separates an ultrasonic portion from a signal received at a microphone, and processing circuitry is provided to determine a delay time of an echo corresponding to the ultrasonic burst signal in that separated ultrasonic portion of the received signal. In another aspect, the equalizer equalizes an ultrasonic portion of the signal received at a microphone, according to frequency response characteristics of the speaker and microphone at the ultrasonic frequencies of the burst.

A system and method from improving the image quality achievable with an ultrasound transducer by using a composite aperture for receiving ultrasound echoes. By using two receive cycles per vector, twice as many transducers may be used for receiving ultrasound imaging data than there are physical channels available in the ultrasound probe. An ultrasound probe utilizing a composite aperture can achieve high image quality from a system have reduced power, size, cost and complexity.

A system and method from improving the image quality achievable with an ultrasound transducer by using a composite aperture for receiving ultrasound echoes. By using two receive cycles per vector, twice as many transducers may be used for receiving ultrasound imaging data than there are physical channels available in the ultrasound probe. An ultrasound probe utilizing a composite aperture can achieve high image quality from a system have reduced power, size, cost and complexity.

A transducer system comprises a first frequency steered transducer array element and a second frequency steered transducer array element that is spaced apart from the first frequency steered transducer array element. The system additionally includes a processing element in communication with the first and second frequency steered transducer array elements. The processing element is configured to receive a first receive electronic signal from the first frequency steered sonar array element, receive a second receive electronic signal from the second frequency steered array sonar element, compare a difference in amplitude between the first receive electronic signal and the second receive electronic signal to determine a cross-track position of an underwater target, and control a display to present an indication of the cross-track position of the underwater target.

A marine sonar display device comprises a display, a memory element, and a processing element. The display displays sonar images. The memory element stores sonar data. The processing element is configured to transmit a transmit electronic signal to a frequency steered sonar element which transmits an array of sonar beams into a body of water, each sonar beam transmitted in a different angular direction, receive a receive electronic signal from the frequency steered sonar element, the receive electronic signal including a plurality of frequency components, calculate an array of sonar data slices, one sonar data slice for each frequency component, generate an array of sonar image slices, one sonar image slice for each sonar data slice, and control the display to visually present the array of sonar image slices in near real time and a historical sequence of at least one sonar image slice.