A method is provided for classifying an object, in particular in the surroundings of a motor vehicle, using an ultrasonic sensor system, the ultrasonic sensor system including a plurality of spatially distributed ultrasonic sensors. A plurality of measurements are carried out continuously during a measurement, an ultrasonic signal being emitted by one of the ultrasonic sensors, a signal being received by at least one of the ultrasonic sensors which includes a plurality of reflected echo signals, so-called multiple echoes, and the received echo signals being associated with an object. A plurality of features may be determined from the received echo signals. The object is classified as a function of a combination of at least two of these features, in particular as a pedestrian.

A direction of arrival estimation apparatus includes at least first and second sub-arrays to receive a reflected wave of a transmission waveform from a target; first and second phasing parts that perform phasing of reception signals at the first and second sub-arrays to generate first and second sub-array beams; an arrival time difference calculation part that calculates first and second correlations of the reception signals of the first and second sub-array beams at first and second time points to find an arrival time difference between times of the reflected wave arriving at the first and second sub-arrays, based on a result of a predetermined operation on the first and second correlations and a time difference between the first time point and the second time point; and a direction of arrival calculation part that finds a direction of arrival of the target based on the arrival time difference.

An underwater acoustic receiver apparatus (100) comprises an acoustic reflector (102, 104, 106, 108) and an acoustic device (110, 114, 116, 118) aimed at the acoustic reflector (102, 104, 106, 108). The acoustic reflector (102, 104, 106, 108) is disposed at a predetermined distance and orientation relative to the acoustic device (110, 114, 116, 118).

Gesture recognition is a key requirement for Human Computer Interaction (HCI) and multiple modalities are explored in literature. Conventionally, channel taps are estimated using least square based estimation and tap corresponding to finger motion is tracked. These assume that noise component is negligible and can reduce the tracking accuracy for low SNR. Thus, to mitigate the above-mentioned limitation, the system and method of the present disclosure explore the feasibility of using speaker and microphone setup available in most of smart devices and transmit inaudible frequencies (acoustic) for detecting the human finger level gestures accurately. More specifically, System implements the method for millimeter level finger tracking and low power gesture detection on this tracked gesture. The system uses a subspace based high resolution technique for delay estimation and use microphone pairs to jointly estimate the multi-coordinates of finger movement.

A method for determining the directional frequency response of an arrangement of transducer elements. The method comprises providing a simulation of locations of the transducer elements, in the spatial domain; providing a beamforming direction and a frequency range; converting the simulation of locations from the spatial domain into corresponding frequency response values in a spatial frequency domain, such that, for each frequency of a plurality of frequencies in the frequency range, a spatial frequency contour is defined, each of the spatial frequency contours intersecting at the origin; determining the frequency response by applying a transformation to the frequency response values for the provided beamforming direction and frequency range, translating the spatial frequency domain into a modified frequency domain, wherein the contours avoid intersecting; and outputting the frequency response. There is further provided a data processing device adapted to perform the method, a computer program, and a computer-readable medium.

A method for determining the directional frequency response of an arrangement of transducer elements. The method comprises providing a simulation of locations of the transducer elements, in the spatial domain; providing a beamforming direction and a frequency range; converting the simulation of locations from the spatial domain into corresponding frequency response values in a spatial frequency domain, such that, for each frequency of a plurality of frequencies in the frequency range, a spatial frequency contour is defined, each of the spatial frequency contours intersecting at the origin; determining the frequency response by applying a transformation to the frequency response values for the provided beamforming direction and frequency range, translating the spatial frequency domain into a modified frequency domain, wherein the contours avoid intersecting; and outputting the frequency response. There is further provided a data processing device adapted to perform the method, a computer program, and a computer-readable medium.

An ultrasonic gesture recognition system is provided that recognizes gestures based on analysis of return signals of an ultrasonic pulse that is reflected from a gesture. The system transmits an ultrasonic chirp and samples a microphone array at sample intervals to collect a return signal for each microphone. The system then applies a beamforming technique to frequency domain representations of the return signals to generate an acoustic image with a beamformed return signal for multiple directions. The system then generates a feature image from the acoustic images to identify, for example, distance or depth from the microphone array to the gesture for each direction. The system then submits the feature image to a deep learning system to classify the gesture.

Aspects of the subject technology relate to a method of correcting sensor position. The method comprises transmitting one or more first pulses of a first frequency range towards a first portion of a seabed and one or more second pulses of a second frequency range towards a second portion of the seabed, and receiving a first set and second set of backscattered data. The method further includes processing the first and second set of backscattered data to form a first and second set of image data and comparing the first set and second set of image data. The method further includes creating one or more error vectors between the first set and second set of image data, and updating the first set of backscattered data based on the one or more error vectors to produce an updated set of image data.

Aspects of the subject technology relate to a method of correcting sensor position. The method comprises transmitting one or more first pulses of a first frequency range towards a first portion of a seabed and one or more second pulses of a second frequency range towards a second portion of the seabed, and receiving a first set and second set of backscattered data. The method further includes processing the first and second set of backscattered data to form a first and second set of image data and comparing the first set and second set of image data. The method further includes creating one or more error vectors between the first set and second set of image data, and updating the first set of backscattered data based on the one or more error vectors to produce an updated set of image data.

A robot cleaner having a main body, a driving unit for moving the main body, a sensing unit for sensing information related to an obstacle, and a controller for controlling the driving unit to prevent collision of the main body with the obstacle. The controller controls the driving unit to reverse the main body with respect to the obstacle so as to prevent the main body from contacting the obstacle based on a distance between the main body and the obstacle.