A method for switching a screen state, a terminal, and computer-readable medium are provided. The method includes: transmitting a transmission sound wave when it is detected that the screen state of the terminal is in a light-on state during a voice communication session, the transmission sound wave being a sound wave of a pre-defined frequency; determining a target detection region when a target receiving sound wave is received through a plurality of pre-installed sound wave receiving devices, the target receiving sound wave being formed by reflecting the transmission sound wave by a target object; and switching the screen state of the terminal from the light-on state into a light-off state when it is determined that the target object is located in the target detection region.

An object detection system includes a plurality of object detection devices disposed at predetermined intervals. Each object detection device includes a transmission unit configured to transmit a transmission wave on which frequency modulation based on chirp signals that change in a frequency pattern different from that of an initial signal is performed subsequently to frequency modulation based on the initial signal so as to be in a mode different from those in the object detection devices including the adjacent object detection devices, a reception unit configured to receive a reception wave as the transmission wave returned in response to reflection on an object, and a detection processing unit configured to detect information related to the object based on information acquired as a result of transmission and reception of the transmission wave and the reception wave.

Systems and methods are described that can include transmitting, from a first wearable computing device, a first ultrasound signal and receiving, by the first wearable computing device and responsive to the first ultrasound signal, a second ultrasound signal from a second wearable computing device. The method can include identifying, by the first wearable computing device, a location of the second wearable computing device with respect to a location of the first wearable computing device where the location of the second wearable computing device can be identified based on a determined time-of-flight of the first ultrasound signal. The method can include establishing a wireless connection between the first wearable computing device and the second wearable computing device where the wireless connection can be based at least in part on the identifier and the identified location associated with the second wearable computing device.

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.

The invention relates to a method for operating a distance sensor (4) of a vehicle (1), in which method a plurality of successive measurement cycles are carried out in an operating mode, wherein, in each measurement cycle, a transmission signal is transmitted, a reception signal (Rx1 to Rx8) is determined on the basis of the transmission signal reflected in a surrounding region (9) of the vehicle (1), the object (8) is classified, and the transmission signal is selected from a plurality of predefined transmission signals in accordance with how the object (8) is classified, wherein the transmission signal is selected in accordance with an assignment rule determined in a learning mode, said assignment rule describing an assignment of the plurality of predefined transmission signals to classes of objects (8), wherein, in each measurement cycle, the object (8) is classified on the basis of the reception signal (Rx1 to Rx8) and the transmission signal is selected in accordance with how the object (8) is classified for subsequent measurement cycles.

In many applications such as automobiles on busy highways, if a lot of vehicles on road are equipped with Doppler radars to help improve driving safety, no matter human-driven or auto-driven, if the radars use same frequency band, avoiding interference between them is a hard task. Assigning distinct frequencies is one of the solutions, however not only it wastes expensive spectrum resource, but also the task itself to dynamically assign frequency to vehicles randomly come together becomes a hard one to do. The disclosed invention of Doppler group radar will allow radar devices to work together using shared frequency band without interfering one another, without sacrificing performance, and without much increase in costs.

A method for determining the elevation angle and/or azimuth angle of a signal received by an ultrasound sensor includes: providing an ultrasound sensor with a frequency-dependent radiation pattern; transmitting a first ultrasound wave at a first frequency; transmitting a second ultrasound wave at a second frequency different from the first frequency; receiving reflections of the first and second waves, the reflections being caused by an object; and determining the elevation angle of the first and second reflected waves based on amplitudes of the reflections of the first and second waves. Determining the elevation angle (and/or azimuth angle includes calculating a ratio between the amplitudes of received reflections of the first and second waves and mapping a calculated ratio to an elevation angle and/or azimuth angle. The mapping is based on a predetermined ratio curve or ratio dataset which associates a certain amplitude ratio to an elevation angle and/or azimuth angle.

A method, device and computer program product for controlling the device by tracking a movement of a hand or other objects. The device receives acoustic signals. At least a portion of the received signals are transformed into two-dimensional sinusoids whose frequencies are proportional to an angle-of-arrival (AoA) and a propagation distance of the reflected signals. An AoA-distance profile is derived based on signals received from the object by evaluating frequencies of the two-dimensional sinusoids. Then, an AoA-distance pair is derived from the AoA-distance profile. A current location of the object is determined based on the estimated AoA-distance pair. The device then performs a command in response to detecting that the user moved to perform the command based on prior and current locations of the object.

Systems and methods are described that can include transmitting, from a first wearable computing device, a first ultrasound signal and receiving, by the first wearable computing device and responsive to the first ultrasound signal, a second ultrasound signal from a second wearable computing device. The method can include identifying, by the first wearable computing device, a location of the second wearable computing device with respect to a location of the first wearable computing device where the location of the second wearable computing device can be identified based on a determined time-of-flight of the first ultrasound signal. The method can include establishing a wireless connection between the first wearable computing device and the second wearable computing device where the wireless connection can be based at least in part on the identifier and the identified location associated with the second wearable computing device.

A Continuous Transmission Frequency Modulated (CTFM) detection apparatus includes a projector, a sensor, and a hardware processor. The projector is configured to transmit underwater a frequency modulated transmission wave based on a transmission signal. The sensor is configured to form a reception beam directed downward and laterally outward to a side of the boat or the ship and receive a reflected wave, the reflected wave comprising a reflection of the transmission wave on a target object. The hardware processor is programmed to at least generate a beat signal based at least in part on the transmission signal and the reflected wave, extract a processing signal from the beat signal, and generate an image information related to the target object based on the extracted processing signal.