The invention refers to a method of using a tag in a localisation system, the method comprising at said tag operating a magnetic induction signal detection circuit to detect signals, and upon detection of a magnetic induction signal comprising a first identification code: correlating the magnetic induction signal comprising said first identification code to an ultrasound signal comprising a second identification code, received via an ultrasound signal detection circuit. If said correlation reveals an association between said first identification code and said second identification code: a radio frequency announcement signal is transmitted via a radio frequency signal transmitter circuit to signify said association. The invention also refers to a method of using a beacon in said localisation system, as well as the localisation system comprising one or more tags and one or more beacons.

A method and system for enabling the determination of a position of a receiver within a space includes transmitting a beacon signal from each of a plurality of beacon devices located at different locations within the space. The beacon signal transmitted from each beacon device has a unique information component and may have a unique frequency pattern of multiple frequencies. Each beacon signal can be distinguishable from the beacon signals transmitted from any other of the beacon devices based on the combination of its unique information component and its unique frequency pattern. The beacon signals are received at a receiver. At the receiver, for each beacon signal of a working subset, time-delay information of the received beacon signal is determined and multilateration is applied to determine the position of the receiver based on the location of each beacon device of the working subset.

An acoustic model determination approach for a real-time locating system is disclosed. The system includes one or more transmitting devices and one or more mobile devices. The acoustic model may be determined by deriving an acoustic representation of sub-structures within the building, and then forming the acoustic model based on the acoustic representation and the location and orientation of the static acoustic transmitting device. In another embodiment, an acoustic signal is transmitted from a static acoustic transmitting device, with the reflected signals received by the same static acoustic transmitting device in a receiving mode. Based on these received acoustic signals, the acoustic model is formed based on the reflected signals and the location and orientation of the static acoustic transmitting device.

An acoustic model determination approach for a real-time locating system is disclosed. The system includes one or more transmitting devices and one or more mobile devices. The acoustic model may be determined by deriving an acoustic representation of sub-structures within the building, and then forming the acoustic model based on the acoustic representation and the location and orientation of the static acoustic transmitting device. In another embodiment, an acoustic signal is transmitted from a static acoustic transmitting device, with the reflected signals received by the same static acoustic transmitting device in a receiving mode. Based on these received acoustic signals, the acoustic model is formed based on the reflected signals and the location and orientation of the static acoustic transmitting device.

A system for tracking a position on a rig site may include a plurality of static beacons of defined positions on the rig site configured to transmit reference signals at a selected triggering time for transmission; at least one moveable receiver at a first location on the rig site configured to receive the reference signals from the plurality of static beacons, determine the reception time of signal, and transmit reception information to a master node via a communication channel; wherein the master node is at a location on the rig site with a reference base time, wherein the master node receives the defined positions and reference times of the plurality of static beacons, and wherein the system is configured to, based on the reception information, determine signal travel times between the static beacons and the at least one moveable receiver, determine the distances between the static beacon and the at least one moveable receiver based on a travel time of the reference signals, and determine a position of the first location.

The present disclosure relates to a location determination system that includes acoustic transmitting devices, location tags, and a wireless mesh network, where the wireless mesh network uses battery-powered devices. A location tag receives acoustic signals (e.g., ultrasound signals) from an acoustic transmitting device. Clocks from members of the wireless mesh network are synchronized by observation of clock pairings, each clock pair formed by respective clocks in a transmitting device that transmits a message and a receiving device that receives the message. By analyzing the observed clock pairings, a best fit between the clock pairings may be determined. After selecting a reference clock, an acoustic transmission schedule may be propagated to the respective acoustic transmitting device.

The present disclosure relates to a location determination system that includes acoustic transmitting devices, location tags, and a wireless mesh network, where the wireless mesh network uses battery-powered devices. A location tag receives acoustic signals (e.g., ultrasound signals) from an acoustic transmitting device. Clocks from members of the wireless mesh network are synchronized by observation of clock pairings, each clock pair formed by respective clocks in a transmitting device that transmits a message and a receiving device that receives the message. By analyzing the observed clock pairings, a best fit between the clock pairings may be determined. After selecting a reference clock, an acoustic transmission schedule may be propagated to the respective acoustic transmitting device.

The present disclosure relates to a location determination system that includes acoustic transmitting devices and mobile devices. A mobile device receives acoustic signals (e.g., ultrasound signals) from an acoustic transmitting device. The mobile device must be able to identify the acoustic transmitting device with particularity when receiving the acoustic signals. It is more efficient to use a short identifier, for example 6 bits, for this purpose because it requires less power to transmit and decode. By utilizing the rotating identifier system described herein, more acoustic transmitting devices can be distinguished than using a time-invariant identifier would otherwise provide, and the transmissions are more secure and therefore less vulnerable to free-riders.

A diver navigation, information and safety buoy system and method. The system and method incorporate a float device, and an ultra-short baseline acoustic array in communication with a diver transponder. The system and method also include a GPS system having a GPS antenna device mounted on the float device. The system also includes an AIS system having an AIS antenna mounted on the float. A diver processor permits a diver's location information to be calculated, and the diver can be navigated to a desired destination.

Devices, non-transitory computer-readable media and methods for providing a haptic signal based upon a detection of an object are disclosed. For example, the processor of a device may transmit a first ultrasonic signal via an ultrasonic emitter and detect an object based upon a receiving of a reflected signal via an ultrasonic detector, where the reflected signal comprises a reflection of the first ultrasonic signal from the object. The processor may further monitor for a second ultrasonic signal via the ultrasonic detector. The device may be associated with a user, and the second ultrasonic signal may be associated with a teammate of the user. The processor may also select whether to provide an instruction to a haptic actuator when the object is detected, based upon whether the second ultrasonic signal is received via the ultrasonic detector.