Techniques for determining occupancy using unobstructed sensor emissions. For instance, a vehicle may receive sensor data from one or more sensors. The sensor data may represent at least locations to points within an environment. Using the sensor data, the vehicle may determine areas within the environment that are obstructed by objects (e.g., locations where objects are located). The vehicle may also use the sensor data to determine areas within the environment that are unobstructed by objects (e.g., locations where objects are not located). In some examples, the vehicle determines the unobstructed areas as including areas that are between the vehicle and the identified objects. This is because sensor emissions from the sensor(s) passed through these areas and then reflected off of objects located farther distances from the vehicle. The vehicle may then generate a map indicating at least the obstructed areas and the unobstructed areas within the environment.

A sensor signal processing unit (100) arranged to detect a configuration of parking slots (1a,1b,1c,1d) based on radar detections received from a radar-based sensor system (120). The unit includes a histogram unit arranged to generate a representation of a spatial distribution of a set of radar detection coordinates, and a detection unit arranged to detect the configuration of parking slots. The detection unit is arranged to detect the configuration of parking slots based on a Fourier transform of the representation of spatial distribution.

A system for virtual aperture array radar tracking includes a transmitter that transmits first and second probe signals; a receiver array including a first plurality of radar elements positioned along a first radar axis; and a signal processor that calculates a target range from first and second reflected probe signals, corresponds signal instances of the first reflected probe signal to physical receiver elements of the radar array, corresponds signal instances of the second reflected probe signal to virtual elements of the radar array, calculates a first target angle between a first reference vector and a first projected target vector from the first reflected probe signal, and calculates a position of the tracking target relative to the radar array from the target range and first target angle.

Methods, apparatus and systems for wirelessly tracking keystrokes on a surface are described. In one example, a described system comprises: a transmitter configured for transmitting, using a transmit antenna, a first wireless signal through a wireless channel of a venue including the surface; a receiver configured for receiving, using a plurality of receive antennas, a second wireless signal through the wireless channel, wherein the second wireless signal comprises a reflection of the first wireless signal by at least one moving object in the venue; and a processor. The processor is configured for: obtaining, regarding each receive antenna, a time series of channel information (CI) of the wireless channel based on the second wireless signal, detecting at least one keystroke on the surface based on the time series of CI (TSCI) obtained regarding each receive antenna, determining at least one location of the at least one keystroke on the surface, and determining at least one key associated with the at least one keystroke based on the at least one location.

Methods, apparatus and systems for wireless proximity sensing are described. In one example, a described system comprises: a transmitter configured for transmitting a first wireless signal through a wireless multipath channel of a venue; a receiver configured for receiving a second wireless signal through the wireless multipath channel; and a processor. The second wireless signal differs from the first wireless signal due to the wireless multipath channel that is impacted by a movement of an object in the venue. The processor is configured for: obtaining a time series of channel information (TSCI) of the wireless multipath channel based on the second wireless signal, wherein each channel information (CI) of the TSCI comprises a plurality of CI components, each of which is associated with an index; computing an inter-component statistics based on the plurality of CI components; computing, based on the inter-component statistics, a proximity information of the object with respect to a reference location in the venue; and performing a task based on the proximity information of the object.

A system and bent-pipe transponder component for determining a location of an individual or object in three dimensional space. The system includes a transmitter configured to transmit a first wireless electromagnetic signal at a first frequency and at least one transponder that is configured to responsively emit a second wireless electromagnetic signal having a second frequency that is frequency-shifted from the first frequency. An included receiver detecting the first and second wireless electromagnetic signals is configured to provide an output of location information for the at least one transponder. A bent-pipe transponder component may include a receiving antenna, an emitting antenna, and a frequency shift stage comprising an oscillator and a first mixer, with the frequency stage mixing a received first wireless electromagnetic signal with the output of the oscillator via the first mixer to produce the emitted second wireless electromagnetic signal.

According to an aspect of the present inventive concept there is provided an autonomous mobile robot comprising: a set of radar sensors, the sensors being arranged at spatially different positions on the mobile robot, the set including at least a first radar sensor having a first main detection lobe extending in front of the robot and a second radar sensor having a second main detection lobe extending in front of the robot, wherein the first radar sensor and the second radar sensor are arranged such that the first main detection lobe and the second main detection lobe intersect in front of the mobile robot.

A sensing system. In some embodiments, the system includes a first imaging radio frequency receiver, a second imaging radio frequency receiver, a first optical beam combiner, a first imaging optical receiver, a second optical beam combiner, and an optical detector array. The first optical beam combiner may be configured to combine optical signals of the imaging radio frequency receivers. The second optical beam combiner may be configured to combine the optical signals of the imaging radio frequency receivers, and the optical signal of the first imaging optical receiver.

There is described a method of verifying a time-of-flight based ranging result in a UWB ranging device, the method comprising: exchanging a sequence of messages between the UWB ranging device and a further UWB ranging device as part of a double-sided ranging process to obtain round times and response times at both the UWB ranging device and the further UWB ranging device; estimating a time-of-flight value based on the round times and response times; and verifying the ranging result by performing a consistency check based on the estimated time-of-flight value and one or more predetermined parameter values. Furthermore, a UWB ranging device and a UWB ranging system are described.

A system for radio-frequency imaging of a structural environment is disclosed, including radio devices configured to transmit radio signals and a radio imaging device configured to receive the radio signals transmitted by the radio devices. The radio signals received at some times are scattered, reflected, or attenuated by an object collocated with an active localization device. The radio signals received at other times are scattered, reflected, or attenuated by the object not collocated with the active localization device. The system can obtain an indication of a location of the active localization device and, based on the radio signals received at the times the object is collocated with the active localization device, generate a radio signature of the object associated with the location. The system can then compute a score indicative of a likelihood that the object is at the location when it is not collocated with the active localization device.