During transmission, a speed of ultrasound pulses gradually reduces due to their energy loss from acoustic impedance. A thickness and a density of piezoelectric (PZT) elements and a sound speed in the PZT elements decides energy of the ultrasound pulses and their detecting depth. A speed of moving objects and an angle of the moving objects with the ultrasound pulses may change a speed of reflected ultrasound pulses and affect their time of flight (TOF) and TOF shift. A method of Coding ultrasound pulses combines advantages of a continuous wave ultrasound and a pulsed wave ultrasound. So, it can be used to obtained the TOF and the TOF shift and calculate the depth and the moving speed of the detecting objects, which also avoids a problem of an aliasing for highly moving speed of the objects.

Circuitry comprising excitation circuitry for supplying a transducer with an excitation signal to generate a detection signal and current monitor circuitry for monitoring current through the transducer.

A proximity sensing function is implemented using a collection of core independent peripherals (CIPs) in a microcontroller without software overhead to the central processor during operation thereof. A pulse width modulation (PWM) peripheral generates a high frequency drive signal that is on for a short duration to an ultrasonic transmitting transducer. An ultrasonic receiving transducer receives reflected ultrasonic pulses during an integration time window. The received pulses are detected and integrated into a voltage value. The integrated voltage value is compared to a prior voltage value average, and if different, generates a proximity sense signal of an object. Direction, distance and speed of the object may also be determined from the voltage values.

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.

An illustrative controller includes: a transmitter to drive an acoustic transducer to generate a first acoustic burst and a second acoustic burst; a receiver coupled to the acoustic transducer to sense a first response to the first acoustic burst and a second response to the second acoustic burst; and a processing circuit to derive output data from the first and second responses in part by determining an offset frequency difference between the first and second responses, wherein the first acoustic burst has a first characteristic frequency and the second acoustic burst has a second characteristic frequency different from the first characteristic frequency.

An illustrative controller includes: a transmitter to drive an acoustic transducer to generate a first acoustic burst and a second acoustic burst; a receiver coupled to the acoustic transducer to sense a first response to the first acoustic burst and a second response to the second acoustic burst; and a processing circuit to derive output data from the first and second responses in part by determining an offset frequency difference between the first and second responses, wherein the first acoustic burst has a first characteristic frequency and the second acoustic burst has a second characteristic frequency different from the first characteristic frequency.

A method for detecting a vehicle intrusion includes a first signal transmission process for alternately transmitting a first signal of a waveform through a first transmission module and a second transmission module at a predetermined period, a first intrusion determination process for analyzing a reflected wave received in response to the transmitted first signal to determine whether the intrusion occurred, a second signal transmission process for transmitting a second signal of a pulse waveform, upon detecting the intrusion as a result of the first intrusion determination process, a second intrusion determination process for analyzing a waveform of a reflected wave received in response to the transmitted second signal to determine whether the intrusion occurred, and transmitting a predetermined alarm message indicating that the intrusion occurred upon detecting the intrusion as a result of the second intrusion determination process.

A method for detecting a vehicle intrusion includes a first signal transmission process for alternately transmitting a first signal of a waveform through a first transmission module and a second transmission module at a predetermined period, a first intrusion determination process for analyzing a reflected wave received in response to the transmitted first signal to determine whether the intrusion occurred, a second signal transmission process for transmitting a second signal of a pulse waveform, upon detecting the intrusion as a result of the first intrusion determination process, a second intrusion determination process for analyzing a waveform of a reflected wave received in response to the transmitted second signal to determine whether the intrusion occurred, and transmitting a predetermined alarm message indicating that the intrusion occurred upon detecting the intrusion as a result of the second intrusion determination process.

Systems and methods are disclosed herein in which multi-level square wave excitation signals are used instead of or in addition to fully-analog excitation signals to drive an array of transceiver elements to create a sound field. Use of multi-level square wave excitation signals produces acceptable transceiver output with reduced complexity, cost, and/or power consumption as compared with use of fully-analog excitation signals. In addition, use of such signals facilitates system implementation using application-specific integrated circuits (ASICs) and is not as restricted in voltage level and speed. At the same time, the benefits and applications of fully-analog excitation signals (e.g., acoustic holography, beam superposition, signal-to-noise ratio (SNR) improvements, suppression of parasitic modes, increased material penetration, potential for coded pulsing algorithms and suppression of side lobes in ultrasonic field) can still be achieved with multi-level square wave excitation signals.

Systems and methods are disclosed herein in which multi-level square wave excitation signals are used instead of or in addition to fully-analog excitation signals to drive an array of transceiver elements to create a sound field. Use of multi-level square wave excitation signals produces acceptable transceiver output with reduced complexity, cost, and/or power consumption as compared with use of fully-analog excitation signals. In addition, use of such signals facilitates system implementation using application-specific integrated circuits (ASICs) and is not as restricted in voltage level and speed. At the same time, the benefits and applications of fully-analog excitation signals (e.g., acoustic holography, beam superposition, signal-to-noise ratio (SNR) improvements, suppression of parasitic modes, increased material penetration, potential for coded pulsing algorithms and suppression of side lobes in ultrasonic field) can still be achieved with multi-level square wave excitation signals.