An access control device of a vehicle is configured to detect the spatial position of the access element of the vehicle safety unit relative to the vehicle via electromagnetically detecting the distances and angles between several low-frequency transmitting antennas of the vehicle safety unit and the low-frequency receiver of the access element. The access control device is also configured to detect the location position of an external induction charging unit relative to the vehicle via electromagnetically measuring the distance and angle between at least two transmitting antennas of several low-frequency transmitting antennas and at least one receiving antenna of the induction charging unit.

In an embodiment, a method for air-writing character recognition includes: determining a position of an object in a monitoring space using a plurality of millimeter-wave radars, where each millimeter-wave radar of the plurality of millimeter-wave radars has a field of view, and where an intersection of the fields of view of the plurality of millimeter-wave radars forms the monitoring space; tracking the position of the object in the monitoring space over time using the plurality of millimeter-wave radars; determining a character symbol depicted by the tracked position of the object over time using a neural network (NN); and providing a signal based on the determined character symbol.

A Real Time Locating System (RTLS) hygiene management and monitoring system for individuals and companies to manage and monitor the hygiene of their surroundings. For example, the system can be used in conjunction with a cleaning device and can include a locating module, a display module, and a cleanliness monitoring system. The locating module determines a location of the cleaning device in an area and to track movement of the cleaning device within the area. The display module includes a graphical layout of the area. The cleanliness monitoring system generates data representative of a path that the cleaning device has traversed in the area and at least one aspect of cleaning behavior of the device in the area. The display module displays the data representative of the path and the data representative of the at least one aspect of cleaning behavior, and one or both of the path and the at least one aspect of cleaning behavior is color-coded on the display module.

A hygiene monitoring and management system including a monitoring module and a display. The management module with an input and that receives data via the input. The received data includes one or more locations of a device in a facility, and the management module further includes one or both of software and hardware configured to generate data representative of cleaning behavior associated with the device based on the received data. The cleaning behavior includes timing and movement of the device in the facility, and a cleanliness level of at least one area in the facility.

To track an object with radar, and achieve greater than range resolution precision, the phase of a difference signal can be utilized and adjusted as the tracked object crosses between resolution ranges. Changes in the object's distance can be detected with greater than range resolution precision by utilizing the phase. Such changes can iteratively inform the determined distance across multiple phase cycles within a single distance range. As the movement of the object approaches, and then crosses, between resolution ranges, the phase as determined within an origin resolution range can be compared with a coincident phase within the destination resolution range and the difference can then be utilized to adjust the phase as the object then remains within the destination resolution range. Such phase adjustments can be applied across multiple resolution ranges, allowing for the tracking of an object, utilizing radar, while achieving greater than range resolution precision.

In a method for initializing at least one network segment of a network for the wireless location of movable locating objects arranged in a limited space using pulsed radio signals, wherein the at least one network segment in the limited space has at least two spaced apart reference nodes which form a chain-shaped communication network and which are autarkic in terms of communication, wherein a locating object arranged in the limited space is able to be located using one of the distance-based trilateration carried out by at least three reference nodes, and wherein general information is communicated by broadcast channels, the reference nodes listen to the broadcast channels in a standby position until initial information about their active participation in the communication network is received.

A wireless communication method in a network comprising one or several beacons and a plurality of end-points, comprising: sending by a beacon a timing message modulated according to a chirp spread spectrum format, receiving said timing message in one or several end-nodes a receiver, detecting said timing message aligning a local frequency reference and/or time reference of the end-node to the time reference of the transmitter by means of said timing message.

A Doppler motion sensor device is used for detecting a motion of an object. The Doppler motion sensor device includes a first antenna and a second antenna. The first antenna is used to transmit or receive a first wireless signal. The second antenna is used to transmit or receive a second wireless signal. A first straight line passing through a first feed-in point and a first middle point of the first antenna is orthogonal to a second straight line passing through a second feed-in point and a second middle point of the second antenna. One of the first wireless signal and the second wireless signal is a transmission signal. The transmission signal is reflected by the object to form the other one of the first wireless signal and the second wireless signal.

In one embodiment, a method includes processing user interactions with an electronic device based on different processing modules. The electronic device includes one or more radar-based transmitters and receivers. The method transmits radio waves into an area in the vicinity of the electronic device from the transmitters and receives at the receivers the radio waves reflected off one or more objects in the vicinity of the electronic device. The method selects either trilateration processing or imaging process to process the received radio waves based on different requirements for processing user interactions.

We describe a sensor system for measuring relative distance between sensors of the system, the sensor system comprising at least two sensors, wherein each said sensor comprises an RF transceiver coupled to a microprocessor and stored program code for controlling the microprocessor, wherein said stored program code comprises code to: send, using said RF transceiver a group of one or more data bits from the sensor to a second sensor; receive, using said RF transceiver, an acknowledgement of reception of said group of data bits from said second sensor; determine a time difference between said sending and said receiving; compensate said time difference from a processing delay by the microprocessor of said second sensor between the second sensor receiving said group of data bits and sending said acknowledgement, to determine timing data reprinting distance to said second sensor.