Time of flight between two or more ultrasonic transceivers is measured using known delays between receiving a trigger and sending an ultrasonic pulse in reply. A receive time is measured from a beginning of a receive phase in which the pulse is detected until receipt of an ultrasonic reply pulse. A trip time is determined from a sum of the receive time and a difference between a known first reference period for a transceiver that sends the trigger pulse and a second know reference period for a second transceiver that sends the reply pulse. The second reference period corresponds to a delay between when the second transceiver receives the initial or subsequent trigger pulse from the first transceiver and when the second transceiver sends the reply pulse.

An object detection device of the present disclosure includes three reception units for receiving reflected waves resulting from reflection of a transmission wave by an object within a detection range, and a determination unit for determining presence or absence of an object to be avoided based on outputs of the three reception units. The determination unit calculates first coordinates and second coordinates at which an object is estimated to be present, based on reception times from when a transmission wave is transmitted until reflected waves are received by the three reception units, and determines whether or not the object needs to be avoided, based on a distance between the first coordinates and the second coordinates.

Systems and methods for boosting low content of received signals involve a vessel (102) towing port side (205) and starboard side (210) impulsive source arrays. The port side and starboard side impulsive source arrays are selectively actuated for a plurality of sequential shots having different signatures.

An obstacle detection apparatus for vehicles includes: a first ultrasonic sensor for detecting a distance to an obstacle; a second ultrasonic sensor at a position of the vehicle for receiving a reflection wave from the obstacle of an ultrasonic wave from the first ultrasonic wave; a notifier that gives a notification of detecting the obstacle present within a preset distance in one or more of predetermined notification areas including a first notification area for the first ultrasonic sensor, and a second notification area for the second ultrasonic sensor detects the obstacle for the vehicle; and a controller that controls contents to be notified by the notifier. Furthermore, the controller determines whether a first indirect wave distance and a second indirect wave distance are used to determine whether to give the notification of detecting the obstacle in the first notification area.

An obstacle detection apparatus for vehicles includes: a first probe wave sensor detecting a direct wave distance as a distance to an obstacle by transmitting a probe wave and receiving a reflection wave of the probe wave reflected by the obstacle; a second probe wave sensor receiving the reflection wave to detect an indirect wave distance as a distance to the obstacle by receiving the reflection wave; an approach determinator determining whether the obstacle is present between the first probe wave sensor and the second probe wave sensor and whether the obstacle is approaching the vehicle; and a distance determinator determining an obstacle distance to be less than or equal to a predetermined distance range when the indirect wave distance falls out of the distance range as the obstacle is present between the first probe wave sensor and the second probe wave sensor and the obstacle is approaching the vehicle.

A sensing system for a vehicle includes a plurality of radio frequency (RF) sensor units disposed at the vehicle so as to have respective fields of sensing exterior of the vehicle. Each RF sensor unit includes a system on chip unit comprising a plurality of transmitting antennae and a plurality of receiving antennae, with each transmitting antenna transmitting RF signals and each receiving antenna receiving RF signals transmitted by each transmitting antenna to provide a respective field of sensing of each of the RF sensor units. Outputs of the RF sensor units are communicated to a control and, responsive to the outputs of the RF sensor units, the control determines the presence of one or more objects exterior the vehicle and within the field of sensing of at least one of the RF sensor units.

A vehicular sensing system includes a plurality of multiple input multiple output (MIMO) radar sensor units disposed at a vehicle so as to have respective fields of sensing exterior of the vehicle. Each MIMO radar sensor unit includes a plurality of transmitting antennas and a plurality of receiving antennas, with each transmitting antenna transmitting radar signals and each receiving antenna receiving radar signals. Outputs of the individual MIMO radar sensor units of the plurality of MIMO radar sensor units are provided to an electronic control unit (ECU) using a communication protocol of the vehicle and, responsive to the outputs of the MIMO radar sensor units, the ECU detects objects present exterior the vehicle. The vehicular sensing system adjusts the total number of transmitting and receiving antennas utilized by the plurality of MIMO radar sensor units in accordance with complexity of a surrounding environment of the vehicle.

There is provided an obstacle detection system using distance sensors including a first distance sensor which is mounted in a vehicle and senses a distance to the obstacle positioned inside a first field of view; a second distance sensor which is mounted in the vehicle to be spaced apart from the first distance sensor in the lateral direction of the vehicle and senses the distance to the obstacle positioned in a second field of view overlapping with the first field of view partially; an auxiliary sensor which is mounted in the vehicle between the first distance sensor and the second distance in the lateral direction of the vehicle and senses presence or absence of, or the distance to, the obstacle at least partially positioned with an overlapping field where the first field of view and the second field of view overlap with each other; and a detection unit detecting the obstacle based on the distances to the obstacle respectively sensed by the first distance sensor and the second distance sensor and the presence or absence, or the distance to the obstacle sensed by the auxiliary sensor.

A distributed acoustic anti-unmanned boat intelligence system (DAAUBS) for detecting unmanned boats (UB) approaching protected sites includes a plurality of airborne defense agents (ADAs) and a base station. Each ADA is equipped with air balloons, tethers, buoys, a directional microphone array, a first computing device, and a transceiver. The first computing device causes at least processor to determine information regarding each approaching UB. The base station includes a control center configured with a wideband communications link configured to communicate with the transceiver of each ADA. The DAAUBS control center includes a second computing device performing an intelligence method. The second processor receives and aggregates the data of each approaching UB and performs adaptive noise cancellation to remove environmental background noise. The second processor uses a deep learning classifier to classify at least one of a type and size of the UB.

An object detection device includes: a wave receiver that receives a reflected wave generated by reflection, by an object, of a transmission wave incident on the object; a determination section that determines whether, in a change over time in an amplitude of the reflected wave received by the wave receiver, an amplitude of a falling portion is greater than a predetermined criterion, the amplitude of the falling portion being decreased after the amplitude has reached a maximum value; and a processing section that, on the basis of a determination by the determination section that the amplitude of the falling portion is greater than the predetermined criterion, performs a process in which the object is treated as an object to be avoided.