Broadband signal transmissions may be used for object detection and/or ranging. Broadband transmissions may comprise a pseudo-random bit sequence or a bit sequence produced using, a random process. The sequence may be used to modulate transmissions of a given wave type. Various types of waves may be utilized, pressure, light, and radio waves. Waves reflected by objects within the sensing volume may be sampled. The received signal may be convolved with a time-reversed copy of the transmitted random sequence to produce a correlogram. The correlogram may be analyzed to determine range to objects. The analysis may comprise determination of one or more peaks/troughs in the correlogram. Range to an object may be determines based on a time lag of a respective peak.

Broadband signal transmissions may be used for object detection and/or ranging. Broadband transmissions may comprise a pseudo-random bit sequence or a bit sequence produced using, a random process. The sequence may be used to modulate transmissions of a given wave type. Various types of waves may be utilized, pressure, light, and radio waves. Waves reflected by objects within the sensing volume may be sampled. The received signal may be convolved with a time-reversed copy of the transmitted random sequence to produce a correlogram. The correlogram may be analyzed to determine range to objects. The analysis may comprise determination of one or more peaks/troughs in the correlogram. Range to an object may be determines based on a time lag of a respective peak.

An ultrasonic-based person detection method. The method comprising the steps of: (a) emitting, from an emitter, an ultrasonic signal, the ultrasonic signal including a component at a first frequency; (b) receiving reflections of the ultrasonic signal, the received signal including components at frequencies greater than and less than the first frequency; (c) determining a difference between an upper portion of the received signal containing a frequency higher than the first frequency, and a lower portion of the received signal containing a frequency lower than the first frequency; and (d) determining, based on the difference between the upper portion and the lower portion, whether a person is present.

An ultrasonic-based person detection method. The method comprising the steps of: (a) emitting, from an emitter, an ultrasonic signal, the ultrasonic signal including a component at a first frequency; (b) receiving reflections of the ultrasonic signal, the received signal including components at frequencies greater than and less than the first frequency; (c) determining a difference between an upper portion of the received signal containing a frequency higher than the first frequency, and a lower portion of the received signal containing a frequency lower than the first frequency; and (d) determining, based on the difference between the upper portion and the lower portion, whether a person is present.

A detection apparatus that includes correlation processing systems that each find a correlation between a predetermined code sequence and a wave detection signal obtained by detecting a phase-modulated input wave at a frequency different from a frequency used by a different one of the correlation processing systems, and thereby generate a correlation signal, level reduction processors that each receive the correlation signal from a corresponding one of the plurality of correlation processing systems and reduce a level of the received correlation signal when the correlation signal is not to be used for detection of the target or do not reduce the level of the received correlation signal when the correlation signal is to be used for detection of the target, and a detector that detects at least presence or absence of the target based on the correlation signal processed by each of the plurality of level reduction processors.

A detection apparatus that includes correlation processing systems that each find a correlation between a predetermined code sequence and a wave detection signal obtained by detecting a phase-modulated input wave at a frequency different from a frequency used by a different one of the correlation processing systems, and thereby generate a correlation signal, level reduction processors that each receive the correlation signal from a corresponding one of the plurality of correlation processing systems and reduce a level of the received correlation signal when the correlation signal is not to be used for detection of the target or do not reduce the level of the received correlation signal when the correlation signal is to be used for detection of the target, and a detector that detects at least presence or absence of the target based on the correlation signal processed by each of the plurality of level reduction processors.

A method for detecting a ground echo signal of an ultrasonic sensor of a vehicle. The ultrasonic sensor emits a signal at a first frequency or having a first frequency profile, the signal is reflected by a roadway surface and the reflected signal is received by the ultrasonic sensor and/or by an additional ultrasonic sensor. The received echo signal is filtered with the aid of a matched filter, the matched filter being adapted to the emitted signal and having a characterizing frequency. In this way a ground echo signal is determined from the filtered signal. The instantaneous vehicle speed is determined and an expected Doppler shift of the reflected signal is determined as a function of the instantaneous vehicle speed. The first frequency or the first frequency profile and/or the characterizing frequency of the matched filter is/are adapted as a function of the Doppler shift to be expected.

A method for detecting a ground echo signal of an ultrasonic sensor of a vehicle. The ultrasonic sensor emits a signal at a first frequency or having a first frequency profile, the signal is reflected by a roadway surface and the reflected signal is received by the ultrasonic sensor and/or by an additional ultrasonic sensor. The received echo signal is filtered with the aid of a matched filter, the matched filter being adapted to the emitted signal and having a characterizing frequency. In this way a ground echo signal is determined from the filtered signal. The instantaneous vehicle speed is determined and an expected Doppler shift of the reflected signal is determined as a function of the instantaneous vehicle speed. The first frequency or the first frequency profile and/or the characterizing frequency of the matched filter is/are adapted as a function of the Doppler shift to be expected.

A method and device for processing an echo signal received from an acoustic sensor. The echo signal is detected over a measurement time interval. A minimum value is ascertained, which describes a minimum amplitude of the echo signal within the measurement interval. An amplitude value is ascertained, which describes an amplitude of the echo signal within a measurement window. The measurement window is a predefined time interval within the measurement interval. A difference is ascertained between the minimum value and the amplitude value. A determination is made whether the echo signal comprises an interference signal of the first type or an interference signal of the second type, based on the ascertained difference.

A method and device for processing an echo signal received from an acoustic sensor. The echo signal is detected over a measurement time interval. A minimum value is ascertained, which describes a minimum amplitude of the echo signal within the measurement interval. An amplitude value is ascertained, which describes an amplitude of the echo signal within a measurement window. The measurement window is a predefined time interval within the measurement interval. A difference is ascertained between the minimum value and the amplitude value. A determination is made whether the echo signal comprises an interference signal of the first type or an interference signal of the second type, based on the ascertained difference.