Systems for position determination using an energy chain for guiding supply lines, which energy chain has a movable run which is fixed at an end to a driver and a stationary run wherein the driver moves back and forth along a track. The system has a sensor device for position determination, which is attached to the driver. In one variant, the system comprises guide components, arranged along the track, for lateral guidance of the energy chain of which components at least one has a reference component acting as a position reference. In another variant of the system, at least each nth chain link of the energy chain has at least one reference component attached thereto. In both variants, the sensor device for position determination interacts with individual reference components, which allows better and more reliable determination of the current position.

An ultrasonic transmitter apparatus is configured to transmit an ultrasonic signal that communicates a binary identifier. The apparatus includes an ultrasound transmission system and is configured to transmit an ultrasonic signal that communicates the binary identifier according to an encoding in which each bit position in the binary identifier is associated with a respective pair of frequencies and with respective first and second time positions in the ultrasonic signal. The value of the bit position in the binary identifier determines which frequency of the pair of frequencies is transmitted at the first respective time position in the ultrasonic signal, with the other frequency of the pair of frequencies being transmitted at the second respective time position in the ultrasonic signal.

An underwater communications network may include spaced apart nodes on a bottom of a body of water. The underwater communications network may also include fiber optic cabling connecting the spaced apart nodes. Each node may include a frame, a node short-range navigation device carried by the frame, and an unmanned underwater vehicle (UUV) carried by the frame after delivering a fiber optic cable along a navigation path from an adjacent node. The UUV may be configured to cooperate with the node short-range navigation device during an end portion of the navigation path adjacent the frame.

A practically implementable robust direction-of-arrival (DoA) estimation approach that is resistant to localization errors due to mobility, multipath reflections, impulsive noise, and multiple-access interference. As part of the disclosed invention the inventors consider infrastructure-less 3D localization of autonomous underwater vehicles (AUVs) with no GPS assistance and no availability of global clock synchronization. The proposed method can be extended to challenging communication environments and applied for the localization of assets/objects in space, underground, intrabody, underwater and other complex, challenging, congested and sometimes contested environments. Each AUV leverages known-location beacon signals to self-localize and can simultaneously report its sensor data and measurement location. The approach uses two known location beacon nodes, where the beacons are single-hydrophone acoustic nodes that are deployed at known locations and transmit time-domain coded signals in a spread-spectrum fashion.

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.

A transmitter is disclosed. The transmitter includes a clock configured to generate one or more output clock signals. The transmitter further includes at least one frequency divider configured to generate a plurality of divided frequencies based on the one or more output clock signals, and a modulator. The transmitter also includes at least one antenna or transducer configured to transmit modulated data. The transmitter includes a memory configured to store instructions, and at least one processor configured to execute instructions performing operations including mapping data to a decimal code value of a plurality of decimal code values, converting the decimal code value to a shrinking base system, and selecting a set of frequencies among the plurality of divided frequencies based on the code value corresponding to the shrinking base system for the decimal code value. The modulator may be configured to modulate the decimal code value using the set of frequencies.

An assembly and method for detecting cross bores involving a sewer system and a gas pipe includes an acoustic generator placed within an interior of the sewer system and an acoustic receiver placed either within an interior of the gas pipe or in proximity to an end of the gas pipe. The acoustic generator generates an acoustic signal to transmit through the interior of a sewer pipe of the sewer system. A controller detects, in response to the acoustic receiver hearing the acoustic signal, a cross bore involving the sewer pipe and the gas pipe. A microphone may be placed within the interior of the sewer system at a location remote from the acoustic generator. In this case, the controller determines, in response to the acoustic receiver not hearing the acoustic signal and the microphone hearing the acoustic signal, that a cross bore involving the sewer pipe and the gas pipe is absent.

An assembly and method for detecting cross bores involving a sewer system and a gas pipe includes an acoustic generator placed within an interior of the sewer system and an acoustic receiver placed either within an interior of the gas pipe or in proximity to an end of the gas pipe. The acoustic generator generates an acoustic signal to transmit through the interior of a sewer pipe of the sewer system. A controller detects, in response to the acoustic receiver hearing the acoustic signal, a cross bore involving the sewer pipe and the gas pipe. A microphone may be placed within the interior of the sewer system at a location remote from the acoustic generator. In this case, the controller determines, in response to the acoustic receiver not hearing the acoustic signal and the microphone hearing the acoustic signal, that a cross bore involving the sewer pipe and the gas pipe is absent.

The disclosed threat response system(s) and method(s) provide a mean to secure an area around the clock. The system includes a plurality of microphones strategically located at various locations of the protected area, a plurality of acoustic beacons to provide navigational support one or more autonomous non-flying (ANF) drones, and a central controller. In one example each of the one or more ANF drones are equipped with an acoustic positioning system that uses beacon signals (e.g., mechanical waves) transmitted by the plurality of acoustic beacons to determine its position relative to the plurality of acoustic beacons. Once an acoustic event is detected, it is analyzed to determine whether there is a threat. When the threat is confirmed, the central controller dispatches one or more of the ANF drones to investigate and/or to engage the target.

The disclosed threat response system(s) and method(s) provide a mean to secure an area around the clock. The system includes a plurality of microphones strategically located at various locations of the protected area, a plurality of acoustic beacons to provide navigational support one or more autonomous non-flying (ANF) drones, and a central controller. In one example each of the one or more ANF drones are equipped with an acoustic positioning system that uses beacon signals (e.g., mechanical waves) transmitted by the plurality of acoustic beacons to determine its position relative to the plurality of acoustic beacons. Once an acoustic event is detected, it is analyzed to determine whether there is a threat. When the threat is confirmed, the central controller dispatches one or more of the ANF drones to investigate and/or to engage the target.