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.

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 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 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.

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.

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 method for measuring a distance between a first device and a second device, the method may include playing, by a first sound output unit, a first correlation tone; receiving, by a first sound sensing unit, the first correlation tone; detecting a start point of a reception of the first correlation tone; receiving, by the first sound sensing unit, a second correlation tone; wherein the second correlation tone is played by a second sound output unit in response to a reception, by a second sound sensing unit, of the first correlation tone; detecting a start point of a reception of the second correlation tone; receiving, by the first sound sensing unit, information about a processing time of the second device; calculating, by a first processing unit, a timing difference between (i) the start point of the reception of the second correlation tone, and (ii) the start point of the reception of the first correlation tone; and determining the distance between the first device and the second device based on a difference between the timing difference and the processing time of the second device; wherein the first processing unit, the first sound sensing unit and the first sound output unit belong to the first device; and wherein the second sound sending unit and the second sound output unit belong to the second device.

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.

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 method for determining the location of a frequency receiver device with respect to at least two frequency originator devices, each of a current location, the method including synchronizing a clock of the frequency receiver device with a clock of one of the at least two frequency originator devices; receiving by the frequency receiver device, a message including an identification code configured for identifying one of the at least two frequency originator devices and obtaining a broadcast time and a current location of the one of the at least two frequency originator devices by looking up a table correlating the at least two frequency originator devices and their respective broadcast times and current locations; calculating a time of flight of the message by calculating the difference between a receive time at which the message is received by the frequency receiver device and the broadcast time.