An obstacle detection device includes an ultrasonic sensor, an obstacle detector to determine presence of an obstacle of interest if an intensity of a received ultrasonic wave exceeds a threshold value, and a threshold value setter to set a short-distance detection threshold value as the threshold value for the obstacle detection in a short-distance detection area in a vicinity of the ultrasonic sensor and to set a long-distance threshold value as the threshold value for the obstacle detection in a long-distance detection area located farther from the ultrasonic sensor than the short-distance detection area, the long-distance threshold value being less than the short-distance detection threshold value. The short-distance detection area is an area where variation in sound pressure distribution of transmitted ultrasonic waves is equal to or greater than the threshold value, and the long-distance detection area includes an area where the variation of the sound pressure distribution of transmitted ultrasonic wave is smaller than the threshold value.

Disclosed are a control method and a control device for an ultrasonic receiving device. The control method includes: determining a target receiver of the ultrasonic receiving device, where the ultrasonic receiving device includes at least two ultrasonic receivers, and the target receiver is one of the at least two ultrasonic receivers on the ultrasonic receiving device that is the nearest to an ultrasonic transmitting device; and controlling a state of each of the at least two ultrasonic receivers on the ultrasonic receiving device based on the determined target receiver. Thus, the ultrasonic ranging error is reduced, and the accuracy of measurement is improved.

A conveyor conveys a sheet along a conveyance path provided with an ultrasonic sensor, and includes: an updating member that successively updates a parameter indicating aged deterioration of the conveyor; a searcher that searches a look-up table storing pieces of noise data of noises predicted to be superimposed on a detection signal of the ultrasonic sensor in accordance with a degree of the aged deterioration, and obtains a piece of noise data corresponding to a current parameter value of the conveyor; and a signal processor that uses, for signal processing, a remaining portion of the detection signal of the ultrasonic sensor excluding a portion corresponding to the piece of noise data obtained by the searcher.

Methods and apparatus to detect proximity of objects to computing devices using near ultrasonic sound waves are disclosed. An example apparatus includes a frequency analyzer to determine power levels of noise in different frequency bands associated with sound waves sensed by a microphone of a computing device. The example apparatus further includes a signal generator to cause a speaker to produce a series of acoustic pulses. A central frequency of the pulses is defined based on the power levels of noise in the different frequency bands. The sound waves are sensed by the microphone to include the pulses and echoes of the pulses reflected off objects in a vicinity of the computing device. The example apparatus also includes an object detection analyzer to determine whether a first object is within an activation region associated with the computing device based on the pulses and the echoes sensed by the microphone.

An object detection device includes: a transmission and reception unit configured to transmit a transmission wave including an ultrasonic wave having directivity in a direction parallel or substantially parallel to a traveling direction of a movable body, and receive a reflected wave from an object; a determination unit configured to determine presence or absence of an abnormality based on a predetermined reference distance and a downward distance between the transmission and reception unit and an object present below the transmission and reception unit in a vertical direction, the downward distance being calculated based on a reflected wave of an ultrasonic wave of the transmission wave traveling downward in the vertical direction from the transmission and reception unit; and an output unit configured to output information regarding the abnormality.

A pulse-echo ranging system (100) and method that processes the reflected signal amplitude profile (9) to determine an accurate and robust distance to a target (16). The method uses the energy decay trend (15) of the reflected signals (13) in order to avoid environmental factors that can degrade the clarity of the reflected signals (13). Results of the computations that use the energy decay trend (15) are then applied to reflected signal amplitude profile (9) in order to obtain an accurate distance to target (16).

An object detection apparatus includes a transmitting portion configured to transmit a transmission wave, a receiving portion configured to receive a reception wave based on the transmission wave which returned, an estimation portion configured to estimate an amount of frequency transition between the transmission wave and the reception wave on the basis of a result of a frequency analysis, a correction portion configured to correct the reception wave to obtain consistency of frequencies with the transmission wave on the basis of an estimation result of the estimation portion, and a detection portion configured to detect information related to the object on the basis of a relation between the transmission wave and the corrected reception wave corrected by the correction portion.

An ultrasonic wave measuring device includes: an ultrasonic wave transmission and reception unit configured to perform ultrasonic wave transmission and reception processing of transmitting ultrasonic waves to an object and receiving the ultrasonic waves reflected by the object, and to output reception signals based on reception of the ultrasonic waves; a zero-crossing detection unit configured to detect a plurality of zero-crossings corresponding to the reception signals whose signal voltages are equal to or higher than a predetermined threshold; and a reception setting unit configured to set a reception zero-crossing used as a reception timing based on the plurality of zero-crossings. The reception setting unit is configured to calculate a difference between a zero-crossing detection time from a transmission timing of the ultrasonic waves to a time at which zero-crossing is detected and a predetermined reference time for each of the plurality of the zero-crossings, and to set one of the zero-crossings at which the difference is minimum among the plurality of zero-crossings as the reception zero-crossing.

In accordance with some embodiments of the disclosed subject matter, mechanisms (which can, for example, include systems, apparatuses, methods, and media) for determining three dimensional location of an object associated with a person at risk of falling down are provided. In some embodiments, the apparatus comprises: an ultrasound detector; an antenna; and a processor, the processor programmed to: detect a first ultrasound signal at a first time using the ultrasound detector; in response to detecting the first ultrasound signal, cause a first wireless signal to be emitted by the antenna; detect a second ultrasound signal at a second time; in response to detecting the second ultrasound signal, cause a second wireless signal to be emitted by the antenna; determine that a first amount of time has passed since the second ultrasound signal was detected; and in response to determining that the first amount of time has passed since the second ultrasound signal was detected, cause the wearable apparatus to enter a low power state.

An obstacle detection device includes an ultrasonic sensor, an obstacle detector to determine presence of an obstacle of interest if an intensity of a received ultrasonic wave exceeds a threshold value, and a threshold value setter to set a short-distance detection threshold value as the threshold value for the obstacle detection in a short-distance detection area in a vicinity of the ultrasonic sensor and to set a long-distance threshold value as the threshold value for the obstacle detection in a long-distance detection area located farther from the ultrasonic sensor than the short-distance detection area, the long-distance threshold value being less than the short-distance detection threshold value. The short-distance detection area is an area where variation in sound pressure distribution of transmitted ultrasonic waves is equal to or greater than the threshold value, and the long-distance detection area includes an area where the variation of the sound pressure distribution of transmitted ultrasonic wave is smaller than the threshold value.