A system includes a computer including a processor and a memory, the memory storing instructions executable by the processor to actuate a vehicle brake according to a specified brake torque, receive user input to exceed the specified brake torque, and actuate a brake fluid valve to attain a brake fluid pressure to maintain the specified brake torque.

Multistatic active coherent sonar systems and methods include reception by floating receiver sonobuoys of acoustic signals emitted by floating source sonobuoys, by both direct propagation from the source sonobuoys and reflection or scattering from a target object. Subsequent calculations based at least in part on those signals can be employed to estimate relative or absolute positions or velocities of the target object and the source and receiver sonobuoys. The estimated relative velocities and positions can be calculated without relying on GPS or other extrinsic positioning signals acquired for each sonobuoy after its deployment. Acoustic signals emitted by a stationary source on the seabed, received by a stationary receiver on the seabed, or reflected/scattered from a bathymetric feature, can be employed to estimate absolute or relative positions or velocities of the target object and the source and receiver sonobuoys.

Ultrasound signal processing circuitry and related apparatus and methods are described. Signal samples received from an ultrasound transducer array in an ultrasound transducer based imaging system may be processed, or conditioned, by application of one or more weighting functions. In some embodiments, one or more weighting functions may be applied to the signal samples in the time domain. In other embodiments, the signal samples may be converted to the frequency domain and one or more weighting functions may be applied in the frequency domain. In further embodiments, one or more weighting functions may be applied in the time domain and one or more weighting functions may be applied in the frequency domain. The weighting functions may be channel dependent and/or channel independent. The processed data can be provided to an image formation processor.

An obstacle detection apparatus includes: a transceiver transmitting a transmission wave and receiving an ultrasonic wave; a transmission controller; a receiver circuit detecting a signal level of a receiving wave; a distance calculator sequentially calculating a distance to an object reflecting the transmission wave; a memory storing the distance to the object; an obstacle determination device determining whether the object is an obstacle; and a reception level monitoring device monitoring the signal level of the receiving wave before the transmission wave being transmitted. When the signal level exceeds a predetermined threshold, the obstacle determination device sets a first number of determination data elements to an increased number of determinations for a predetermined period to be used for determining whether the object is the obstacle, as being larger than a second number of determination data elements used when the signal level does not exceed the predetermined threshold.

In non-limiting examples of the present disclosure, systems and methods for dynamically updating contour maps are provided. A first water level for a body of water may be determined by a computing device. A location within the body of water may be identified. A second water level relating to the identified location within the body of water may be determined, and the second water level and the first water level may be compared. Upon comparing the first and second water levels, a contour map for the body of water may be automatically updated.

An embodiment of a 4D data ultrasound imaging system includes a matrix of transducer elements suitable for transmitting and for receiving ultrasound signals, said transducer elements being divided into sub-matrixes suitable for receiving in a delayed way a same acoustic signal, a plurality of reception channels with one of said reception channels being associated with one of said transducer elements, a beamformer device including a plurality of storage cells arranged in re-phasing matrixes, each re-phasing matrix being associated with a corresponding sub-matrix with each row associated with one of said transducer elements, said storage cells including an input storage stage that is selectively associated with a row and a reading output stage that is selectively associated with a buffer; each storage cell that belongs to a same column has the input stage that is dynamically activated in sequential times with respect to another storage cell of the same column for storing the same delayed acoustic signal, said storage cells that belong to the same column have the output stage that is simultaneously activated.

Sonar imagery captured during a trip on a body of water can be played back to users, forming a trip replay. However, since the depth of the body of water varies drastically over the course of the trip, the resulting sonar image captured and played over the trip replay may result in loss of detail near shallow depths (even though such detail was captured and is available). Embodiments of the present invention seek to provide the ability to zoom in on portions of the sonar image during trip replay. Additionally, further zoom features, such as bottom lock and canopy lock, provide additional functionality.

Techniques are disclosed for systems and methods to provide accurate and reliable compact sonar systems for mobile structures. A sonar system includes multiple sensor channels, each comprising a sonar transmitter and a sonar receiver, and a logic device configured to provide control signals and receive sensor signals from the sensor channels. The logic device is configured to provide transmission signals to sonar transducer assemblies, where signal patterns of the transmission signals are differentiated based at least in part on frequency content. Acoustic returns are processed using the signal patterns to reduce inter-channel pickup between the sensor channels. Resulting sonar data and/or imagery may be displayed to a user and/or used to adjust a steering actuator, a propulsion system thrust, and/or other operational systems of the mobile structure.

In one form, an acoustic signal is generated for an acoustic transducer, where the acoustic transducer is susceptible to reverberation that defines a close proximity indication zone. The start of a close proximity indication zone window is defined after the generation of the acoustic signal at a first time. During the close proximity indication zone window, a signal is received from the acoustic transducer. When the signal is received, an obstacle is detected in the close proximity indication zone if the magnitude of a first pulse received from the transducer at a second time is less than a first threshold but greater than a second threshold for a debounce time. Additionally, a magnitude of a second pulse received from the transducer outside the close proximity indication zone window at a third time should be less than the second threshold but greater than a third threshold for the debounce time. In this form, the third time is equal to the first time plus two times the difference between the second time and the first time.

A proximity sensing function is implemented using a collection of core independent peripherals (CIPs) in a microcontroller without software overhead to the central processor during operation thereof. A pulse width modulation (PWM) peripheral generates a high frequency drive signal that is on for a short duration to an ultrasonic transmitting transducer. An ultrasonic receiving transducer receives reflected ultrasonic pulses during an integration time window. The received pulses are detected and integrated into a voltage value. The integrated voltage value is compared to a prior voltage value average, and if different, generates a proximity sense signal of an object. Direction, distance and speed of the object may also be determined from the voltage values.