A method, system and computer program product for tracking movement of an object, such as a hand. Speakers of a device to be controlled transmit frequency modulated continuous wave (FMCW) audio signals. These signals are reflected by the object and received by the microphones at the controlled device. The received and transmitted audio signals are mixed. A fast Fourier transform (FFT) is then performed on the mixed audio signals. One or more peak frequencies in the frequency domain of the FFT mixed audio signals are selected and used to estimate the distance between the object and the speakers of the controlled device. Furthermore, the velocity of the object is estimated. The coordinates of the object are then computed using the estimated distance between the object and the speakers and microphones of the controlled device and the estimated velocity of the object.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for motion detection using a communication channel carrier signal. In one aspect, a method includes, for each of one or more communication channels, wherein each communication channel has a center frequency that is different from the center frequency of each other communication channel: determining mean power levels from consecutive power samples at the center frequency, determining a difference between the mean power levels of two consecutive power samples at the center frequency, and determining whether physical motion is occurring in a monitored area based on the difference between the mean power levels.

A method for ascertaining a three-dimensional position of a reflection point of an object in the environment of a vehicle using an ultrasonic sensor having at least three sensor elements. At least two sensor elements are arranged at a horizontal offset to one another and at least two sensor elements are arranged at a vertical offset to one another. The method includes: transmitting at least two ultrasonic signals using at least one of the sensor elements of the ultrasonic sensor, wherein the two ultrasonic signals are transmitted chronologically one after the other, and the two ultrasonic signals are transmitted in different spatial directions and/or with respectively differently shaped sonic cones and/or with respectively different ultrasonic frequencies; sensing the transmitted ultrasonic signals, each reflected on an object, as reflection signals using the at least three ultrasonic sensor elements; and ascertaining the three-dimensional position of a reflection point of the object.

A method for using an active sonar includes an acoustic antenna exhibiting a continuous bandwidth having a spectral emission width of at least two octaves and an electronic system for generating control signals for the acoustic antenna, the method comprising: dynamically selecting a plurality of distinct sonar functioning or operating modalities chosen from escort, surveillance, pursuit, dissuasion and communication, each using a different fraction of the emission bandwidth of the acoustic antenna, referred to as a channel; and using the electronic system to generate a plurality of control signals for the acoustic antenna corresponding to the selected functioning modalities, the electronic system being suitable for allowing the sonar to function according to a plurality of independent and simultaneous operating modalities. And sonar system for implementing such a method is also provided.

A method for using an active sonar includes an acoustic antenna exhibiting a continuous bandwidth having a spectral emission width of at least two octaves and an electronic system for generating control signals for the acoustic antenna, the method comprising: dynamically selecting a plurality of distinct sonar functioning or operating modalities chosen from escort, surveillance, pursuit, dissuasion and communication, each using a different fraction of the emission bandwidth of the acoustic antenna, referred to as a channel; and using the electronic system to generate a plurality of control signals for the acoustic antenna corresponding to the selected functioning modalities, the electronic system being suitable for allowing the sonar to function according to a plurality of independent and simultaneous operating modalities. And sonar system for implementing such a method is also provided.

Apparatus is provided to detect motion of a target reflecting one or more pure tone signals, comprising transmission of one or more pure tone acoustic signals, reception of the signal reflected by a target ensonified by the transmitted signal, and motion detection of the ensonified target from analysis of the Discrete Fourier Transform (DFT) of the received signal, in particular values of the time-variance of energy within adjacent frequency bins in the signal DFT, where the emitted tone has a frequency at the boundary between the two adjacent frequency bins.

Apparatus is provided to detect motion of a target reflecting one or more pure tone signals, comprising transmission of one or more pure tone acoustic signals, reception of the signal reflected by a target ensonified by the transmitted signal, and motion detection of the ensonified target from analysis of the Discrete Fourier Transform (DFT) of the received signal, in particular values of the time-variance of energy within adjacent frequency bins in the signal DFT, where the emitted tone has a frequency at the boundary between the two adjacent frequency bins.

An endpoint among a plurality of endpoints, synchronizes a clock across the plurality of endpoints. The endpoint generates a received ultrasonic signal by transducing ultrasonic sound received at a microphone from a spatial region. The ultrasonic sound includes an identical ultrasonic signal transmitted from the plurality of endpoints and echoes from the spatial region. The identical ultrasonic signal is generated with respect to the synchronized clock. The endpoint computes an error signal based on removing the identical ultrasonic signals and the echoes from the received ultrasonic signal. The endpoint detects motion in the spatial region based on a change in the error signal over time.

An endpoint among a plurality of endpoints, synchronizes a clock across the plurality of endpoints. The endpoint generates a received ultrasonic signal by transducing ultrasonic sound received at a microphone from a spatial region. The ultrasonic sound includes an identical ultrasonic signal transmitted from the plurality of endpoints and echoes from the spatial region. The identical ultrasonic signal is generated with respect to the synchronized clock. The endpoint computes an error signal based on removing the identical ultrasonic signals and the echoes from the received ultrasonic signal. The endpoint detects motion in the spatial region based on a change in the error signal over time.

Aspects presented herein may enable a wireless device to dynamically change the frequencies of its pilot tones based on the distance of one or more objects detected, thereby enabling the wireless device to utilize the advantages of both high frequency pilot tone and low frequency pilot tone. In one aspect, a wireless device transmits a first pilot tone at a first frequency. The wireless device detects whether there is an object within a specified distance of the wireless device based on a reflected signal of the first pilot tone. The wireless device transmits a second pilot tone at a second frequency based on at least one object being detected within the specified distance, where the second frequency is higher than the first frequency. The wireless device calculates a first distance of the at least one object with respect to the wireless device based the second pilot tone.