An ultrasonic motion activity detector is configured to, in each of a series of frames: obtain an ultrasonic signal derived from a transmitted ultrasonic signal; derive an activity signal based on a difference between the obtained signal in a present frame and at least one previous frame; determine a peak value of the activity signal in a first time window of the frame; determine a peak value of the activity signal in a second time window of the frame, wherein the first time window is different from the second time window; calculate a ratio of the peak value of the activity signal in the first time window of the frame to the peak value of the activity signal in the second time window of the frame; and compare the calculated ratio with a threshold value, and, in frames in which the calculated ratio exceeds the threshold value, determine that there is motion of an object relative to the detector.

Studies have shown that using smartphones while walking increases the probability of pedestrians colliding with obstacles. Techniques are presented for providing real-time warnings to distracted users of smartphones. The techniques are implemented by an application which makes use of sensors commonly found in most smartphone. By estimating distances to nearby objects using acoustic signals, a generalized solution is achieved without requiring any prior knowledge of the user's environment. The process can be enhanced by using images acquired from the phone's rear camera.

A method for detecting a moving object in a scene includes providing sampled ultrasonic echo signals from the scene; determining echo envelopes of the sampled ultrasonic echo signals; determining differentials of successive echo envelopes for providing echo envelope differentials; determining the absolute values of the echo envelope differentials; and conducting a classification based on the determined absolute values of the echo envelope differentials for determining a relative movement of the moving object.

An ultrasonic testing device includes: a signal acquiring unit which receives a reflected echo signal relating to a reflected echo of ultrasonic waves from an object being inspected, a defect detecting unit which detects a defect of the object being inspected on the basis of the reflected echo signal, and a display unit which displays the detection result of the defect detecting unit. The defect detecting unit uses the maximum signal strength of the reflected echo signal exceeding a first threshold value to detect the defect. The first threshold value is a value with which the signal strength is less than the maximum signal strength of the reflected echo signal from the surface of the object, using as an evaluation range an interval between a position which is positioned a first distance from the surface of the object and a bottom surface of the object.

The disclosure provides a terminal and a method for ranging using. The terminal comprises an electro-acoustic transducer (1), which has a vibrating component (11), an ultrasonic receiving component (13), a driving component (12) and a control component (14) arranged in the terminal, wherein the control component (14) receives a ranging instruction, controls the driving component (12) to drive the vibrating component (11) to output an ultrasonic signal, receives an ultrasonic signal output by the ultrasonic receiving component (13) returned after colliding, by the output ultrasonic signal, with a target object, and calculates a distance between the terminal and the target object.

Methods and systems are disclosed for employing an ultrasonic sensor to identify a stationary object. The ultrasonic transducer emits an ultrasonic pulse and receives returned signals corresponding to the emitted ultrasonic pulse. The returned signals are evaluated for candidate echoes of a first object. Characteristics of the received returned signals are compared to determine the first candidate echo represents a stationary object.

A device comprises a processor communicatively coupled with an ultrasonic sensor which is configured to repeatedly emit ultrasonic pulses during transmit periods which are interspersed with receive periods. Returned ultrasonic signals corresponding to the emitted ultrasonic pulses are received by the ultrasonic sensor during the receive periods. The processor is configured to direct the ultrasonic sensor to listen, during a listening window, for a potentially interfering ultrasonic signal from a second ultrasonic sensor. The listening window is prior to a transmit period of the transmit periods. In response to detecting the potentially interfering ultrasonic signal during the listening window, the processor is configured to adjust operation of the ultrasonic sensor to avoid an ultrasonic collision with the second ultrasonic sensor to facilitate coexistence of the ultrasonic sensor and the second ultrasonic sensor in an operating environment shared by the ultrasonic sensor and the second ultrasonic sensor.

The present invention relates to a system for monitoring user presence relative to an electronic device, and related method and computer implemented software. The electronic device including at least one acoustic transducer being configured to operate within the ultrasonic range, the least one acoustic transducer being configured to detect a user presence within a predetermined range from the device, wherein the system is configured to turn the at least one transducer off for a predetermined first time period after the detection of a user, at the end of said first time period, activating the acoustic transducer for detecting the user presence.