Provided are methods for detecting objects within a vehicle. The methods can include emitting at least one auditory signal within the vehicle during at least one first time interval; measuring a second auditory signal emitted by an object within the vehicle during the second time interval subsequent to the at least one first time interval, where the emission of the second auditory signal is caused by the emission of the least one first auditory signal; determining a location of the object within the vehicle based on the measurement of the second auditory signal; and generating an alert to a user indicating the location of that object. Systems and computer program products are also provided.

A method of operating electro-acoustical transducers such as PMUTs involves applying to the transducer an excitation signal over an excitation interval, acquiring at the transducer a ring-down signal indicative of the ring-down behavior of the transducer after the end of the excitation interval, and calculating, as a function of said ring-down signal, a resonance frequency of the electro-acoustical transducer. A bias voltage of the electro-acoustical transducer can be controlled as a function of the resonance frequency. An acoustical signal received can be transduced into an electrical reception signal and a damping parameter of the electro-acoustical transducer can be calculated as a function of the ring-down signal so that a cross-correlation reference signal can be synthesized as a function of the resonance frequency and the damping ratio of the electro-acoustical transducer. Such a cross-correlation reference signal can be used for cross-correlation with the electrical reception signal to improve the reception quality.

A method for acquiring the surrounding environment of a motor vehicle. The motor vehicle has at least one ultrasound sensor. The ultrasound sensor includes an ultrasound transducer for sending, the ultrasound sensor receiving acoustic environmental signals, in particular audible environmental signals, in that the ultrasound sensor is controlled in its evaluation in such a way that sound waves having frequencies below a resonant frequency of the ultrasound transducer, in particular audible sound waves, of an environmental signal are acquired and evaluated. Environmental signals are understood as acoustic signals that are not produced by the ultrasound transducer itself, but rather by an external sound source that in particular differs from the motor vehicle. This can be for example the siren of a rescue vehicle or emergency vehicle, or the horn of some other motor vehicle.

A method for contact detection for an ultrasonic sensor system installed in a concealed or unconcealed manner is disclosed. The method involves detecting reference surroundings information, comprising a time profile of a signal with: noise signal information relating to a wall material and/or airborne sound signal information, using an ultrasonic sensor of the ultrasonic sensor system; storing the reference surroundings information; detecting real-time surroundings information, comprising a time profile of a signal with: noise signal information relating to the wall material and/or airborne sound signal information and/or object sound signal information relating to an object in contact with the wall material, using the ultrasonic sensor; and forming a difference signal between the surroundings information of reference surroundings information and real-time surroundings information, using a computational unit. The difference signal can be interpreted in a further step.

Disclosed herein are systems and methods for estimating target ranges, angles of arrival, and speed using optimization procedures. Target ranges are estimated by performing an optimization procedure to obtain a denoised signal, performing a correlation of a transmitted waveform and the denoised signal, and using a result of the correlation to determine an estimate of a distance between the sensor and at least one target. Target angles of arrival are estimated by determining ranges at which targets are located, and, for each range, constructing an array signal from samples of received echo signals, and using the array signal, performing another optimization procedure to estimate a respective angle of arrival for each target of the at least one target. Doppler shifts may also be estimated using another optimization procedure. Certain of the optimization procedures use atomic norm techniques.

An object detector includes: a triangulation calculation unit that performs triangulation calculation for detecting a location of an object based on first distance information calculated based on direct waves in which transmitted waves transmitted from a first transmission and reception unit are reflected by an object and received by the first transmission and reception unit, and second distance information calculated based on indirect waves in which transmitted waves transmitted from a second transmission and reception unit arranged in a location different from the first transmission and reception unit are reflected by an object and received by the first transmission and reception unit; and a prohibition processing unit that prohibits triangulation calculation when a difference between first velocity information indicating a velocity of an object calculated based on the direct waves and second velocity information indicating a velocity of an object calculated based on the indirect waves exceeds a predetermined range.

An acoustic, preferably ultrasonic, wave emission and/or reception device, including a wave emitter configured to transmit waves at an emission frequency, and a receiver of preferably ultrasonic waves, separate from the emitter, having a resonance frequency, and configured to receive waves generated by the emitter and including direct waves and reflected waves, wherein the device includes a resonance frequency modulator of the receiver and a control unit configured to control the resonance frequency modulator during a predetermined time period, so as to reduce the sensitivity of the receiver during the predetermined time period by moving the resonance frequency of the receiver away from the emission frequency of the emitter. The acoustic device relates to the field of ultrasonic sensors, particularly PMUTs or CMUTs, having a high quality factor.

A method for obtaining a position of a peripheral device for an audiovisual entertainment system, the method comprising: controlling an audio source to output an audio signal at a first time; determining a second time at which the audio signal arrives at an audio detector, wherein the peripheral device comprises at least one of the audio source and audio detector; and estimating a position of the peripheral device based on an acoustic time-of-flight between the first time and the second time

Methods, apparatus, systems and articles of manufacture to detect changes in a physical environment are disclosed. An example apparatus includes a descriptor generator to generate a first descriptor, the descriptor generator including: a chirp producer to emit a chirp into the environment, a chirp recorder to record a response to the chirp from the environment, and a chirp response encoder to generate an encoding of the response to the chirp; a descriptor similarity generator to generate a similarity value, the similarity value to compare the first descriptor to a second descriptor; and a physical change indicator to, in response to the similarity value exceeding a similarity threshold, indicate that a physical change has occurred in the environment.

A device and method for reducing noise of an external measurement sensor of mobility, including a storage unit that stores measurement values of an external measurement sensor of mobility including an ultrasonic sensor measuring distance values between the mobility and an object outside the mobility; and an operation unit that generates a plurality of functions capable of being derived from the measurement values stored in the storage unit, derives a final function having the most measurement values within a first range, among the plurality of functions, derives an estimated value that is an expected value of the measurement value through the final function, and selects a candidate final value that is the closest to the estimated value within a second range, among actual measurement values at a time point corresponding to the estimated value, as a final value.