A method and a system for generating a plurality of ranging sound signals for positioning a mobile device are provided. The method includes: each of a plurality of ranging signal generating devices, which are connected to an audio signal cable and are located at different positions in an area, generating a ranging sound signal based on a synchronization signal transmitted on the audio signal cable, whereby location of the mobile device within the area can be obtained based on records of the ranging sound signals made by the mobile device. Accordingly, a plurality of speakers connected in series are able to be controlled to reproduce ranging sound signals for positioning a mobile device.

A method and a system for generating a plurality of ranging sound signals for positioning a mobile device are provided. The method includes: each of a plurality of ranging signal generating devices, which are connected to an audio signal cable and are located at different positions in an area, generating a ranging sound signal based on a synchronization signal transmitted on the audio signal cable, whereby location of the mobile device within the area can be obtained based on records of the ranging sound signals made by the mobile device. Accordingly, a plurality of speakers connected in series are able to be controlled to reproduce ranging sound signals for positioning a mobile device.

A method for detecting a position of a mobile body moving on a plane includes setting X-axis and Y-axis direction reference lines on the plane, disposing a dummy mobile body on intersection points of the reference lines, detecting a position of the dummy mobile body, determining position variation amounts at the intersection points as an X-axis direction error and a Y-axis direction error based on a difference from true position data, determining X-axis and Y-axis direction error approximate formulas based on the errors to calculate errors at each position on the reference lines, detecting the position of the mobile body, correcting acquired detected X-Y coordinate data by a linear interpolation method using the X-axis and Y-axis direction error approximate formulas, and obtaining position data close to the true position of the mobile body.

Techniques are provided for audio-based detection and tracking of an acoustic source. A methodology implementing the techniques according to an embodiment includes generating acoustic signal spectra from signals provided by a microphone array, and performing beamforming on the acoustic signal spectra to generate beam signal spectra, using time-frequency masks to reduce noise. The method also includes detecting, by a deep neural network (DNN) classifier, an acoustic event, associated with the acoustic source, in the beam signal spectra. The DNN is trained on acoustic features associated with the acoustic event. The method further includes performing pattern extraction, in response to the detection, to identify time-frequency bins of the acoustic signal spectra that are associated with the acoustic event, and estimating a motion direction of the source relative to the array of microphones based on Doppler frequency shift of the acoustic event calculated from the time-frequency bins of the extracted pattern.

A method for motion tracking and text recognition, the method including a step of generating ultrasound waves with a transmitter; a step of receiving the ultrasound waves at a receiver, the receiver including sensors that record the ultrasound waves; a step of estimating with a processor, angle-of-arrival information for the ultrasound waves; a step of associating the angle-of-arrival information with a gesture; a step of extracting features from the gesture; and a step of classifying the gesture as a specific text character based on the extracted features by comparing the extracted features with known text characters stored in one or more templates.

Ultrasonic transmitters periodically transmit ultrasonic ranging signals, and an ultrasonic receiver receives the ultrasonic ranging signals on a mobile device in order to locate the mobile device in a venue. A controller determines a noise level in the venue, and varies a sound level of the periodically ranging signals based on the determined noise level, thereby optimizing the position of the mobile device.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

A phase array acoustic device using array of horns and optional faceplates is presented. Said horn phased-array acoustic device can be used as a passive sensor, a sound projector, or both (sonar).

It is shown that by correct selection of the fill-factor and apodization faceplate, grating-lobes and side-lobes cab be greatly reduced.

An optional use of acoustic valves as phase-shifter in the wave domain to improve Signal to Noise Ratio is presented.

An optional aperiodic tiling of the horns' mouth to reduces aliasing is presented.

A range-finding and/or object-positioning system comprises one or more target devices; one or more reference devices communicating with said one or more target devices via one or more wireless signal sets, each wireless signal set comprising at least a first-speed signal having a first transmission speed and a second-speed signal having a second transmission speed, and the first transmission speed being higher than the second transmission speed; and at least one processing unit performing actions for determining at least one distance between one target device and one reference device based on the time difference between the receiving time of the first-speed signal and the receiving time of the second-speed signal of the wireless signal set communicated between said reference and target devices.

The present group of inventions relates to methods and systems for positioning underwater objects, and more particularly to methods and systems in which satellite signals are received by receivers disposed on sonar buoys, the coordinates of the sonar buoys are determined by means of computation modules on the sonar buoys, location data and identification data are transmitted in the form of sonar signals emitted by transmitters on the sonar buoys, the signals are received with the aid of a receiver disposed on an underwater object, and the coordinates of the underwater object are determined according to the time delay of receipt of the sonar signals from the sonar buoys, the location of which is known. The present solution can be used in simultaneously determining the geographical position of an unlimited number of mobile underwater objects, remotely operated underwater vehicles, divers, marine animals, etc. in motion. According to the invention, signals from the aforementioned sonar buoys are encoded in the form of periodic signals tethered to GPS/GLONASS clocks, all transmitters of the sonar signals are disposed at the same depth, and during decoding of the signals from the sonar buoys, direct signals from the sonar buoys are isolated from reflected signals. The system implements the aforementioned method. The achieved technical result is more accurate positioning of the underwater objects.