A method for controlling a vehicle capable of detecting the presence of a passenger in the vehicle includes steps of: scanning an interior of the vehicle based on ultrasonic signals and constructing spatial data on the interior of the vehicle; and re-scanning the interior of the vehicle based on ultrasonic signals when preset conditions are satisfied and outputting a sensing result when a change of the ultrasonic signals, which is greater than a reference value, is detected in the previously constructed spatial data.

This invention relates to apparatus and methods for measuring the time-of-flight of a signal. The signal may be acoustic energy or electromagnetic energy such as x-ray, radio frequency, microwave, millimeter-wave, radar, and laser. Unlike unambiguous ranging devices that measures the phases of two or more signals to determine the time-of-flight and requires long averaging to achieve some degree of accuracy, this invention phase lock one or more transmitter signals to the corresponding received signals in predetermined phase relationships and measures the frequencies of one or more variable frequency oscillators having frequencies several times higher than the frequency of the transmitter signal to determined the time-of-flight with much higher accuracy.

An interferometric synthetic aperture acoustic imager is disclosed. Specifically, an acoustic imaging system includes an acoustic transmitter, an acoustic receiver array, a signal processing system, a navigation data system, and a meteorological data system. The acoustic transmitter and the acoustic receiver array are mounted on transceiver array. The navigation data system includes a Position and Orientation System for Land Vehicles system which receives data from two Global Positioning System antennas, an inertial measurement unit, and a wheel encoder mounted on a vehicle wheel. The system also includes meteorological data system that records temperature, relative humidity, and barometric pressure. The meteorological data may be used to adjust the received acoustic data based on atmospheric conditions.

A survey system including a multibeam echo sounder and a beam selector for selecting beams with the largest amplitudes.

A survey system including a multibeam echo sounder and a beam selector for selecting beams with the largest amplitudes.

An object detection device includes a drive signal generator that generates a drive signal including frequency modulation, a first correlation filter that performs correlation detection between the reception signal and a first reference signal corresponding to the drive signal, a first determiner that determines, based on the correlation signal from the first correlation filter, whether the reception signal is a reflected wave of the probe wave transmitted from the transmitter, a second correlation filter that performs correlation detection between the reception signal and a second reference signal corresponding to a portion of the drive signal, a third correlation filter that performs correlation detection between the reception signal and a third reference signal corresponding to another portion of the drive signal having higher frequencies than the second reference signal, and a second determiner that determines whether there is an object within a detection region based on correlation signals from the second and third correlation filters.

An object detection device includes a drive signal generator that generates a drive signal including frequency modulation, a first correlation filter that performs correlation detection between the reception signal and a first reference signal corresponding to the drive signal, a first determiner that determines, based on the correlation signal from the first correlation filter, whether the reception signal is a reflected wave of the probe wave transmitted from the transmitter, a second correlation filter that performs correlation detection between the reception signal and a second reference signal corresponding to a portion of the drive signal, a third correlation filter that performs correlation detection between the reception signal and a third reference signal corresponding to another portion of the drive signal having higher frequencies than the second reference signal, and a second determiner that determines whether there is an object within a detection region based on correlation signals from the second and third correlation filters.

An ultrasonic wave is output from a speaker of a head-worn device. A microphone signal is obtained from a microphone of the head-worn device that senses the ultrasonic wave as it reflects off an ear of a user. Heart activity such as a heart rate of the user is determined based at least on the microphone signal. Other aspects are also described and claimed.

An ultrasonic wave is output from a speaker of a head-worn device. A microphone signal is obtained from a microphone of the head-worn device that senses the ultrasonic wave as it reflects off an ear of a user. Heart activity such as a heart rate of the user is determined based at least on the microphone signal. Other aspects are also described and claimed.

MEMS ultrasonic transducer, MUT, device, comprising a semiconductor body with a first and a second main face, including: a modulation cavity extending into the semiconductor body from the second main face; a membrane body suspended on the modulation cavity and comprising a transduction membrane body and a modulation membrane body; a piezoelectric modulation structure on the modulation membrane body; a transduction cavity extending into the membrane body, the transduction membrane body being suspended on the transduction cavity; and a piezoelectric transduction structure on the transduction membrane body. The modulation membrane body has a first thickness and the transduction membrane body has a second thickness smaller than the first thickness. In use, the modulation membrane vibrates at a first frequency and the transduction membrane vibrates at a second frequency higher than the first frequency, to emit and/or receive acoustic waves at a frequency dependent on the first and the second frequencies.