The present disclosure provides a detection system and a detection method. The microphone of the detection system receives the response signal formed according to the shape of the sealed cavity. The conversion unit transfers the response signal in the time domain to the frequency domain signal in the frequency domain. The calculation unit obtains every frequency value corresponding to the frequency gradient being zero of each frequency waveform which is chosen of the response signal. The average unit averages every frequency value corresponding to the frequency gradient being zero of each chosen frequency waveform into the average frequency value and outputs an average frequency value. The determination unit determines whether the average frequency value is located in the corresponding frequency tolerance range, so that the wearing status of the in-ear earphone is confirmed.

An object detection device includes a transceiver that transmits ultrasonic waves encoded with frequency modulation and receives an ultrasonic wave and outputs a reception signal, a first quadrature detector that generates and outputs a complex reception signal based on quadrature detection of the reception signal, a second quadrature detector that generates and outputs a complex reference signal based on quadrature detection of the reference signal, a correlation filter that performs correlation detection between the complex reception signal and the complex reference signal and outputs a correlation signal, and a code determiner that determines a code included in the reception signal based on the correlation signal.

A method and an analysis system for determining a state of a diaphragm of an ultrasound sensor during operation is disclosed. The diaphragm of the ultrasound sensor is excited with a first excitation signal in a predefined first frequency profile. Based on this, a first voltage profile, which depends on a frequency of the first excitation signal, is measured. Analogously, a second voltage profile is determined by applying a second excitation signal to the diaphragm and then carrying out a measurement. These two voltage profiles are shifted so that respective positions of maxima of the two voltage profiles are matched to one another in a predefined frequency range. A third voltage profile, which runs between the shifted first and second voltage profiles, is determined. Based on the third voltage profile, electrical parameters are determined by a model for continuous excitation of the diaphragm to determine the state of the diaphragm.

A method and an analysis system for determining a state of a diaphragm of an ultrasound sensor during operation is disclosed. The diaphragm of the ultrasound sensor is excited with a first excitation signal in a predefined first frequency profile. Based on this, a first voltage profile, which depends on a frequency of the first excitation signal, is measured. Analogously, a second voltage profile is determined by applying a second excitation signal to the diaphragm and then carrying out a measurement. These two voltage profiles are shifted so that respective positions of maxima of the two voltage profiles are matched to one another in a predefined frequency range. A third voltage profile, which runs between the shifted first and second voltage profiles, is determined. Based on the third voltage profile, electrical parameters are determined by a model for continuous excitation of the diaphragm to determine the state of the diaphragm.

A method for measuring, using a radar or sonar, the velocity with respect to the ground of a carrier moving parallel to the ground, includes the following steps: a) orienting the line of sight of the radar or sonar toward the ground; b) emitting a plurality of radar or sonar signals (P.sub.1-P.sub.N) that are directed toward the ground, and acquiring respective echo signals (E.sub.1-E.sub.N); c) processing the acquired echo signals so as to obtain, for one or more echo delay values, a corresponding Doppler spectrum; d) for the or at least one the echo delay value, determining a high cut-off frequency of the corresponding Doppler spectrum; and e) computing the velocity of the carrier with respect to the ground on the basis of the one or more high cut-off frequencies. A system allowing such a method to be implemented.

An object detection device includes a signal generator configured to generate a drive signal including an identification signal for identifying ultrasonic waves, a transmitter configured to transmit an ultrasonic wave as a probe wave in response to the drive signal, a receiver configured to receive the ultrasonic wave to generate a reception signal, and a determiner configured to analyze frequencies of the reception signal to determine whether the received wave is a reflected wave of the probe wave, thereby detecting an object. The drive signal includes a ramp-up signal generated to be followed by the identification signal and is used to ramp up an amplitude of the probe wave. A frequency of the ramp-up signal is set to include a frequency at which a transmission/reception efficiency is higher than a transmission/reception efficiency at each of a maximum frequency of the identification signal and a minimum frequency of the identification signal.

A method for operating multiple sensors of a vehicle in at least partially spatially coinciding detection areas and in a shared frequency domain. In the method, at a transmission point in time, at least two sensors transmit simultaneously on separate instantaneous frequencies separated by a frequency gap, the frequency gap including at least one instantaneous receive bandwidth of the sensors, each instantaneous frequency being blocked for a use by the sensors after the transmission point in time for the duration of a time gap, the time gap including at least one signal propagation time across a reception range of the sensors.

A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.

A method for determining a change in a distance, a location prompting method and an apparatus and a system thereof are provided. The method includes: sending, by a receiving terminal, a paring request to a server for the server to forward the paring request to a transmitting terminal, and to allocate a frequency band for the receiving terminal and the transmitting terminal after the transmitting terminal accepts the paring request; acquiring, by the receiving terminal, an acoustic wave signal of a frequency sent by the transmitting terminal, wherein the frequency is determined by the transmitting terminal based on the allocated frequency band; determining, by the receiving terminal, a change in the acquired acoustic wave signal; and determining, by the receiving terminal, a change in a distance between the transmitting terminal and the receiving terminal according to the change in the acquired acoustic wave signal.

A moving object detection system comprises: a transmission waveform setting section to set a transmission signal in such a way that a frequency of the transmission signal is linearly changed; a transmitting section to transmit the transmission signal; a receiving section to receive a reception signal resulting from a reflection of the transmission signal at an object; a Doppler coefficient estimating section to estimate a Doppler coefficient associated with a movement of the object by performing arithmetic processing on a waveform of the reception signal at a present time point and waveforms of the reception signal at one or more past time points, the one or more past time points being earlier than the present time point by one or more specified periods of time; and an object detection section to detect the object based on the transmission signal, the Doppler coefficient, and the reception signal.