There is provided a safety method of detecting and signaling presence of a danger related to a danger source, the method comprising providing a base station at the danger source comprising first detectors and second detectors, the base station being adapted to determine an angular position of a target detected by a first detector among the first detectors within a detection zone based on an angular orientation of the first detector known a priori by the base station, and to determine a distance of the target by activating a second detector among the second detectors to measure the distance between the target and the base station in response to the target detection; and providing targets with portable target devices adapted to send signals in response to signals received from the first detectors of the base station. The first detectors are radio frequency transceivers and the second detectors are ultrasound transceiver. There is also provided a safety system for detecting and signaling presence of a target in danger zone.

There is provided a safety method of detecting and signaling presence of a danger related to a danger source, the method comprising providing a base station at the danger source comprising first detectors and second detectors, the base station being adapted to determine an angular position of a target detected by a first detector among the first detectors within a detection zone based on an angular orientation of the first detector known a priori by the base station, and to determine a distance of the target by activating a second detector among the second detectors to measure the distance between the target and the base station in response to the target detection; and providing targets with portable target devices adapted to send signals in response to signals received from the first detectors of the base station. The first detectors are radio frequency transceivers and the second detectors are ultrasound transceiver. There is also provided a safety system for detecting and signaling presence of a target in danger zone.

A mobile robot includes a chassis, a shell moveably mounted on the chassis, and a cutting assembly mounted to the chassis. The mobile robot also includes a communication system that includes an antenna module disposed on a rear portion of the mobile robot. The antenna module includes a base assembly, and an antenna assembly mounted to the base assembly by a spring. The antenna assembly includes a ranging antenna, and at least three angle antennas arranged axisymmetrically about the ranging antenna, such that the ranging antenna and the three angle antennas define a tetrahedral geometry for determining an angle of arrival for one or more incident signals.

A system and method for locating objects using radio frequency identifiers is provided. Each object to be located by the user has an object unit attached thereto with a RFID transponder. The user carries a proximity unit with a RFID transponder and warning devices. The method comprises: -a controller receives the instruction to locate a specific object; the controller obtains RFID readings, from the main intermediate units associated with location areas, with information about the object units detected; -determining the location area of the object to be located; -sending information to the user about the location area; -detecting the presence of the proximity unit carried by the user when it is within the location area; -repeatedly obtaining, using readings of the RFID signal strength, information about the distance between the proximity unit and the object unit, reporting it to the user using warning devices.

A method for locating a user in a wireless network is disclosed. A mobile computer seeking to determine its location within a building detects the signal strength of one or more wireless base stations placed at known locations throughout the building. The mobile computer uses this measured signal strength to determine its location via a signal-strength-to-location table look-up. A table of known locations within the building and the base station signal strength at those locations is searched to find the most similar stored signal strength to the signal strength detected. The location corresponding to the most similar stored signal strength is determined to be the current location of the mobile computer. Alternatively, a number of signal strengths from the table can be used and the corresponding locations can be spatially averaged to determine the location of the mobile computer. The table can be derived empirically, by placing a mobile computer at the known locations and detecting the signal strength of the wireless base stations at those locations, or the table can be derived mathematically by taking into account a reference signal strength, the distance between the reference point and the known location, and the number of walls between the reference point and the known location. As an alternative, the base stations can detect the signal strength of the mobile computer. In such a case, the table would relate a known position of the mobile computer to the signal strength of the mobile computer at that location as detected by the one or more base stations.

A femtocell calibration solution is provided that uses the known location of the femtocell to calibrate timing based locating systems. The calculated time differences of different signals sent between macrocells and a mobile device can be used to solve for a reference time difference that accounts for the timing differences of the unsynchronized macrocells. The reference time difference can then be used to solve for the location of another mobile device if the calculated time differences between that mobile device and the macrocells are known. The solution can include taking many measurements of the calculated time difference at the first mobile device in order to average them to get a more accurate reference time difference. The solution can further include ceasing measurements at the first mobile device when the mobile device is no longer within range of the femtocell.

A radio frequency signal mediator configured indoors passively receives signals from a user wireless device and determines layer two radio access network measurement data from the signals. At least one other radio frequency signal mediator in the same space also passively receives signals from the user wireless device and determines layer two radio access network measurement data from the signals. The radio frequency signal mediators send the data to a location determining device that determines a location for the user device based on the at least two sets of data and send the location data to a location server.

A radio frequency locator system and method. First, second and third reference devices are operable to transmit a plurality of spread spectrum chirp signals frequency offset from one another. An object device is operable to receive the plurality of spread spectrum chirp signals, the object device is further operable to evaluate the received plurality of spread spectrum chirp signals for relative phase shifts between the plurality of spread spectrum chirp signals and derive a fine propagation time between the reference devices and the object device using the phase shifts between the spread spectrum chirp signals. The reference devices determine their location independent of the object device and determine the location of the object device as a function of each of their locations and of their range to the object device.

A wireless alarm and location system and method of locating an object are provided. The system includes a transceiver contained within a housing enclosure. At least one activation element is located at least partially within the housing enclosure. At least a first omnidirectional signal is communicated from the transceiver upon activation of the activation element. An alarm and location element is positioned remote from the housing enclosure, wherein the alarm and location element receives the first omnidirectional signal and calculates a location of the housing enclosure.

The present disclosure provides a system, method and computer program for anonymous localization. The location of a mobile device can be determined based on signal strength from one or more access points and a radio map. A radio map can be generated by measuring signal strength at a set of fingerprints, which are a finite set of reference points within the area to be mapped.