The present invention relates to a device and a method for presence detection in the vicinity of a device. The device including an acoustic receiver and corresponding analyzing unit for analyzing the received signals, and an acoustic transmitter, the transmitter and received being configured to operate within a predetermined acoustic frequency range. The method including the steps of receiving and analyzing acoustic signals from the environment within said frequency range and evaluating the periodicity and volume of the signals and identifying frequency ranges and/or time windows with low risk for interference, the transmitter being configured to transmit a presence detection signal within the identified frequency range and time windows, the receiver receiving reflections from the transmitted presence detection signals from which the analyzing unit indicates the possible presence of a user.

An apparatus for distance measurement using ultrasonic waves may include: a memory configured to store an applied voltage profile that indicate voltages to be applied to a transducer at a plurality of different operational frequencies of transducer, a transducer including a transmitter configured to generate ultrasonic waves with a frequency modulated waveform, and a receiver configured to receive an echo signal reflected back from a measurement object; and a processor configured to control the transducer based on the applied voltage profile, and measure a distance to the measurement object based on the echo signal.

An apparatus for distance measurement using ultrasonic waves may include: a memory configured to store an applied voltage profile that indicate voltages to be applied to a transducer at a plurality of different operational frequencies of transducer, a transducer including a transmitter configured to generate ultrasonic waves with a frequency modulated waveform, and a receiver configured to receive an echo signal reflected back from a measurement object; and a processor configured to control the transducer based on the applied voltage profile, and measure a distance to the measurement object based on the echo signal.

A method includes configuring a transmitter to provide at least three output levels used to form an output signal. The method further includes adjusting a duration of at least one of the output levels to control an average value of the output signal independently of an amplitude of a first harmonic of the output signal.

Disclosed are a receiver control circuit and a terminal. The receiver control circuit includes: a smart power amplifier module, a coder-decoder, and a receiver. The smart power amplifier module is electrically connected to the receiver by a first switch module. The first switch module includes a first switch component unit that is formed by a metal oxide semiconductor field-effect transistor (MOSFET). The first switch module further includes a first follower unit, where the first follower unit is configured to keep an unchanged voltage difference between a gate electrode of the MOSFET of the first switch component unit and a drain electrode thereof, and a gate electrode voltage of the MOSFET of the first switch component unit is greater than a drain electrode voltage thereof. The coder-decoder is electrically connected to the receiver by the second switch module. The second switch module includes a second switch component unit.

An object detection device includes a drive signal generator that generates a drive signal including frequency modulation, a first correlation filter that performs correlation detection between the reception signal and a first reference signal corresponding to the drive signal, a first determiner that determines, based on the correlation signal from the first correlation filter, whether the reception signal is a reflected wave of the probe wave transmitted from the transmitter, a second correlation filter that performs correlation detection between the reception signal and a second reference signal corresponding to a portion of the drive signal, a third correlation filter that performs correlation detection between the reception signal and a third reference signal corresponding to another portion of the drive signal having higher frequencies than the second reference signal, and a second determiner that determines whether there is an object within a detection region based on correlation signals from the second and third correlation filters.

An object detection device includes a drive signal generator that generates a drive signal including frequency modulation, a first correlation filter that performs correlation detection between the reception signal and a first reference signal corresponding to the drive signal, a first determiner that determines, based on the correlation signal from the first correlation filter, whether the reception signal is a reflected wave of the probe wave transmitted from the transmitter, a second correlation filter that performs correlation detection between the reception signal and a second reference signal corresponding to a portion of the drive signal, a third correlation filter that performs correlation detection between the reception signal and a third reference signal corresponding to another portion of the drive signal having higher frequencies than the second reference signal, and a second determiner that determines whether there is an object within a detection region based on correlation signals from the second and third correlation filters.

An ultrasonic distance sensor is provided. The ultrasonic distance sensor according to an embodiment includes: a signal generator configured to generate a frequency-modulated continuous ultrasonic signal array; a gating switch configured to perform time gating to allow part of ultrasonic signals in the continuous ultrasonic signal array to pass therethrough; a transmitter configured to emit ultrasonic signals, having passed through the gating switch, toward an object; a receiver configured to receive an echo signal reflected from the object; and a signal processor configured to measure a location of the object by using the echo signal.

An ultrasonic distance sensor is provided. The ultrasonic distance sensor according to an embodiment includes: a signal generator configured to generate a frequency-modulated continuous ultrasonic signal array; a gating switch configured to perform time gating to allow part of ultrasonic signals in the continuous ultrasonic signal array to pass therethrough; a transmitter configured to emit ultrasonic signals, having passed through the gating switch, toward an object; a receiver configured to receive an echo signal reflected from the object; and a signal processor configured to measure a location of the object by using the echo signal.

An ultrasonic measuring system is described for detecting an obstacle using a resonant transducer element for transmitting an ultrasonic pulse and for generating a received signal which includes the ultrasonic echo pulse reflected from the obstacle, the transducer element generating a decay signal having its resonance frequency after transmitting an ultrasonic pulse. The ultrasonic measuring system includes an evaluation unit having a control unit which is designed to activate the transducer element for transmitting the ultrasonic pulse with the aid of a frequency-modulated transmitted signal generated by the control unit, the frequency modulation taking place with the aid of a modulation signal in such a way that the signature of the ultrasonic pulse differs from that of the decay signal. The evaluation unit is designed to recognize the echo pulse based on an evaluation of a correlation signal which is generated with the aid of at least one correlation filter and which originates from the correlation of the signal generated by the resonant transducer element with the transmitted signal. Furthermore, a corresponding method is provided for detecting an obstacle with the aid of ultrasound, as well as a vehicle assistance system having the ultrasonic measuring system.