A method for obtaining a position of a peripheral device for an audiovisual entertainment system, the method comprising: controlling an audio source to output an audio signal at a first time; determining a second time at which the audio signal arrives at an audio detector, wherein the peripheral device comprises at least one of the audio source and audio detector; and estimating a position of the peripheral device based on an acoustic time-of-flight between the first time and the second time

Embodiments of the present disclosure provide a positioning system and positioning method. A reverse calibrator for respectively calibrating relative coordinates of at least three ultrasound generators; a processor for generating a carrier signal, multiplying the carrier signal with a spread spectrum pseudo random code to obtain ranging signal, controlling each ultrasound generator to emit ranging signal, and extracting acoustic characteristic parameter of the ranging signals; a device being positioned for capturing ranging signals emitted by each generator, extracting acoustic characteristic parameter of each of the captured ranging signals; determining an ultrasonic delay time of each ultrasonic ranging signal; calculating relative coordinates of the device.

Embodiments of the present disclosure provide a positioning system and positioning method. A reverse calibrator for respectively calibrating relative coordinates of at least three ultrasound generators; a processor for generating a carrier signal, multiplying the carrier signal with a spread spectrum pseudo random code to obtain ranging signal, controlling each ultrasound generator to emit ranging signal, and extracting acoustic characteristic parameter of the ranging signals; a device being positioned for capturing ranging signals emitted by each generator, extracting acoustic characteristic parameter of each of the captured ranging signals; determining an ultrasonic delay time of each ultrasonic ranging signal; calculating relative coordinates of the device.

The present invention provides methods and systems for tracking motion in multiple dimensions, including multiple dimensions, including a transmitter probe fixture, a receiver array, and an electronic control unit.

A location position system can include a plurality of beacons arranged a grid formation divided into a plurality of sub-grids. A mobile computing device can implement a location position application and can receive a radio signal from a particular beacon of the plurality of beacons. The radio signal can comprise a data component uniquely identifying the particular beacon, which can be used to identify a particular sub-grid of the plurality of sub-grids. An audio signal can be received from each of a set of sub-grid beacons associated with the particular sub-grid. Each audio signal can: (i) have a frequency in the frequency range of 16 kHz to 24 kHz and a transmission delay from a reference time, (ii) lack any additional identifying data, and (iii) be separately transmitted from the radio signal transmitted by the particular beacon. The mobile computing device can determine its position based on the received audio signals.

A location position system can include a plurality of beacons arranged a grid formation divided into a plurality of sub-grids. A mobile computing device can implement a location position application and can receive a radio signal from a particular beacon of the plurality of beacons. The radio signal can comprise a data component uniquely identifying the particular beacon, which can be used to identify a particular sub-grid of the plurality of sub-grids. An audio signal can be received from each of a set of sub-grid beacons associated with the particular sub-grid. Each audio signal can: (i) have a frequency in the frequency range of 16 kHz to 24 kHz and a transmission delay from a reference time, (ii) lack any additional identifying data, and (iii) be separately transmitted from the radio signal transmitted by the particular beacon. The mobile computing device can determine its position based on the received audio signals.

Time of flight between two or more ultrasonic transceivers is measured using known delays. First and second transceivers are duty cycled, each having a respective receive period that is less than a measurement period during which the transceivers are configured to receive transmissions. An ultrasonic trigger pulse is transmitted by the first transceiver. The second transceiver, upon receiving the trigger pulse, transmits an ultrasonic response pulse after a first predefined delay time that is known to the first transceiver and greater than the receive period of the second transceiver. Subsequently, the first transceiver receives the ultrasonic response pulse and determines a receive time. The first transceiver determines the distance between the first transceiver and the second transceiver from a speed of sound, an elapsed time between the time of transmission of the trigger pulse and the receive time, and the first predetermine delay time.

Time of flight between two or more ultrasonic transceivers is measured using known delays. First and second transceivers are duty cycled, each having a respective receive period that is less than a measurement period during which the transceivers are configured to receive transmissions. An ultrasonic trigger pulse is transmitted by the first transceiver. The second transceiver, upon receiving the trigger pulse, transmits an ultrasonic response pulse after a first predefined delay time that is known to the first transceiver and greater than the receive period of the second transceiver. Subsequently, the first transceiver receives the ultrasonic response pulse and determines a receive time. The first transceiver determines the distance between the first transceiver and the second transceiver from a speed of sound, an elapsed time between the time of transmission of the trigger pulse and the receive time, and the first predetermine delay time.

An optical safety sensor is inexpensively implemented. An optical safety sensor includes: a plurality of light projectors/receivers (a first light projector/receiver and a second light projector/receiver), which includes light projecting portions and light receiving portions; distance measurement portions, which measure distances using the time from light projecting to light receiving; and detection portions, which detect, based on measurement results, an abnormality occurring in any one of the plurality of light projectors/receivers; each of the light receiving portion provided in the plurality of light projectors/receivers receives reflected light caused by the light projected from the light projecting portions of all the plurality of light projectors/receivers.

An optical safety sensor is inexpensively implemented. An optical safety sensor includes: a plurality of light projectors/receivers (a first light projector/receiver and a second light projector/receiver), which includes light projecting portions and light receiving portions; distance measurement portions, which measure distances using the time from light projecting to light receiving; and detection portions, which detect, based on measurement results, an abnormality occurring in any one of the plurality of light projectors/receivers; each of the light receiving portion provided in the plurality of light projectors/receivers receives reflected light caused by the light projected from the light projecting portions of all the plurality of light projectors/receivers.