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 for estimating an acoustic influence of walls of a room, comprising emitting a known excitation sound signal, receiving a set of measurement signals, each measurement signal being received by one microphone in a microphone array and each measurement signal including a set of echoes caused by reflections by the walls, solving a linear system of equations to identify locations of image source and estimating the acoustic influence based these image sources. The signal model includes a convolution of: the excitation signal, a multichannel filter (M) representing the relative delays of the microphones in the microphone array, the relative delays determined based on a known geometry of the microphone array, and a directivity model ν(n, p) of the driver(s) in the form of an anechoic far-field impulse response as a function of transmit angle.

A method for estimating an acoustic influence of walls of a room, comprising emitting a known excitation sound signal, receiving a set of measurement signals, each measurement signal being received by one microphone in a microphone array and each measurement signal including a set of echoes caused by reflections by the walls, solving a linear system of equations to identify locations of image source and estimating the acoustic influence based these image sources. The signal model includes a convolution of: the excitation signal, a multichannel filter (M) representing the relative delays of the microphones in the microphone array, the relative delays determined based on a known geometry of the microphone array, and a directivity model ν(n, p) of the driver(s) in the form of an anechoic far-field impulse response as a function of transmit angle.

An underwater active sonar system and method for measuring instrument velocity with respect to a boundary surface is disclosed. The system includes an acoustic transducer configured to transmit and receive a plurality of acoustic beams in different directions. The system also includes a processor configured to detect a boundary surface within each beam; iteratively filter received acoustic signals backscattered from the transmitted beams with an adaptive filter and associated bandwidth that is successively decreased for each iteration; and measure instrument velocity with respect to the boundary surface.

An underwater active sonar system and method for measuring instrument velocity with respect to a boundary surface is disclosed. The system includes an acoustic transducer configured to transmit and receive a plurality of acoustic beams in different directions. The system also includes a processor configured to detect a boundary surface within each beam; iteratively filter received acoustic signals backscattered from the transmitted beams with an adaptive filter and associated bandwidth that is successively decreased for each iteration; and measure instrument velocity with respect to the boundary surface.

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.

An autonomous vehicle includes a first ultrasonic sensor and a second ultrasonic sensor that is included in a daisy chain with the first ultrasonic sensor, wherein the first ultrasonic sensor is electrically connected to the second ultrasonic sensor in the daisy chain by way of a twisted pair wire. The autonomous vehicle further includes an electronic control unit (ECU) for the first ultrasonic sensor and the second ultrasonic sensor, the ECU is included in the daisy chain with the first ultrasonic sensor and the second ultrasonic sensor, wherein the ECU is electrically connected to the first ultrasonic sensor and the second ultrasonic sensor by way of the twisted pair wire, and further wherein the ECU is in bidirectional communication with the first ultrasonic sensor and the second ultrasonic sensor by way of differential signaling over the twisted pair wire.

Provided are a sonar system and transducer assembly for producing a 3D image of an underwater environment. The sonar system may include a housing mountable to a watercraft having a transmit transducer that may transmit sonar pulses into the water. The system may include at least one sidescan transducer array in the housing that receives first and second sonar returns with first and second transducer elements and converts the first and second returns into first and second sonar return data. A sonar signal processor may then generate a 3D mesh data using the first and second sonar return data and at least a predetermined distance between the transducer elements. An associated method of using the sonar system is also provided.

Provided are a sonar system and transducer assembly for producing a 3D image of an underwater environment. The sonar system may include a housing mountable to a watercraft having a transmit transducer that may transmit sonar pulses into the water. The system may include at least one sidescan transducer array in the housing that receives first and second sonar returns with first and second transducer elements and converts the first and second returns into first and second sonar return data. A sonar signal processor may then generate a 3D mesh data using the first and second sonar return data and at least a predetermined distance between the transducer elements. An associated method of using the sonar system is also provided.

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.