Abstract: A sonic blind spot monitoring system for alerting a driver when a vehicle is positioned in a blind spot. The sonic blind spot monitoring system includes a vehicle. A sonar device is coupled to the vehicle for emitting a sonar wave into an area adjacent to the vehicle corresponding to a blind spot for a driver of the vehicle. The sonar device includes a sonar receptor for receiving a reflection of the sonar wave for detecting an object in said blind spot. A display device is coupled to the vehicle. The display device is positioned within the vehicle whereby the display device is visible to the driver of the vehicle. The display device is operationally coupled to the sonar device for displaying a visual signal when the sonar device detects the object in the blind spot.

Abstract: In a control and management system for automobiles, a central processor in the system connects traditionally unrelated vehicle subsystems together to realize synergistic functions such as smart driving, automatic parking, etc. A master interface having a display is employed in the system to help a user control and manage the vehicle functions.

Abstract: A device for detecting objects, especially used as a parking assistance device in a motor vehicle, includes a plurality of distance sensors, at least one microcontroller configured to control the distance sensors and an output unit. The distance sensors emit a signal in accordance with an identifier that is modified over time by the microcontroller.

Abstract: An overhead-view display system for a vehicle is provided. The display system comprises a reference vehicle indicator within an overhead field of view and at least three field of view display segments. Each display segment represents a physical region adjacent the reference vehicle and includes a first indicator adapted to display the existence of another vehicle within the region and the relative distance between the reference vehicle and the other vehicle. In another embodiment, each field of view display segment includes a second indicator adapted to represent a direction of change of relative distance between the reference vehicle and the other vehicle, and possibly the vehicle types. Thus, the disclosed display system communicates information on the vehicle's operating environment to the vehicle operator quickly, completely and with minimal driver distraction.

Abstract: A recreational vehicle having an extendable slide-out controlled by an actuator assembly is provided with a damage avoidance system. The damage avoidance system determines if the slide-out is in an adverse state and, if the adverse state is detected, inhibits the actuator assembly from moving the slide-out. The slide-out is in the adverse state if (a) a collision between the slide-out and a nearby object is imminent, (b) a collision has recently occurred, or (c) a resistive force is acting on the slide-out which substantially inhibits the actuator assembly from moving the slide-out. The damage avoidance system comprises a sensor module for monitoring the state of the slide-out and for providing an override signal to the actuator assembly, wherein the override signal is indicative of the slide-out being in the adverse state.

Abstract: A navigational system for surface vessels that provides warning of impending grounding occurrences. A data base of bottom contours and submerged obstructions is compared to various indicators of the surface vessel's position and motion to provide alerts and to display bottom hazards ahead of the vessel.

Abstract: Ultrasound is used to determine, by echo ranging, the distance of objects in front of a user for allowing a visually impaired pedestrian to walk safely. A double circuit allows two simultaneous measurements. Distances measured are converted into human paces or steps. Then each ear of the human receives measurement information. The user can calibrate the apparatus for his or her own stride.

Abstract: Safety apparatus and method for sensing the presence of an object in a safety zone including at least one ultrasonic transducer having an asymmetrical transmission field and received signal processing circuitry operative to receive signals reflected from objects within the asymmetrical transmission field and to discard signals lying outside an asymmetrical detection field lying within the asymmetrical transmission field and defining the safety zone.

Abstract: The collision with pedestrian prevention system according to the present invention comprises pedestrian detection means, road surface conditions detection means, road information accumulation means, vehicle position detection means, vehicle state detection means, processing means, information output means, and vehicle control means. Because of the configuration, the driver is alerted the presence of any pedestrian on a pedestrian's crossing and can immediately correct operations for handling the vehicle without being perplexed by the information just about to finish crossing the road. This system works only when there is the possibility of collision between a pedestrian on a pedestrian's crossing and a vehicle, and provides automatic controls for decelerating or stopping the vehicle when the driver can stop the vehicle by emergently braking over a distance from the vehicle to the pedestrian's crossing.

Abstract: In a device for distance measurement having at least one electroacoustic transducer for transmitting an ultrasonic signal and subsequently receiving an ultrasonic signal reflected from an object, the transmitted power of the transducer can be varied. In the case of a low transmitted power, the oscillation of the transducer decays more rapidly after the transmission time, with the result that it is possible even very soon to receive echoes without interference from the post-pulse oscillation of the transducer. It is therefore possible to measure even very small distances.

Abstract: A process for recognizing the course of the road ahead for a motor vehicle shall be provided, in which the velocity of the vehicle is determined and the position and the velocity of objects located ahead are determined by rigid search antennas oriented in the direction of travel via a radar sensor system, and which makes possible a simple, forward-looking recognition of the course of the road by special evaluation of the measured position and velocity data available. The roadside-specific targets are filtered out of the fixed target by the threshold value comparison of the fixed target amplitudes, and the current distances between the vehicle and the side of the road are determined in discrete angle ranges by ordering filtration. The distances from the side of the road, estimated for each angle range, are sent as characteristics to a classifier for the prediction of the curve type lying ahead, and they are used as support values for a nonlinear regression to obtain a curvature parameter of the curve.

Abstract: An obstacle detection system for a vehicle which is capable of detecting nearby and remote objects successfully by use of a combination of an electromagnetic wave sensors and ultrasonic wave sensors. The system of the present invention includes a plurality of ultrasonic wave sensors each transmitting an ultrasonic wave around the vehicle and receives a reflected wave thereof for detection of nearby obstacles around the vehicle, and an electromagnetic waver sensor which transmits an electromagnetic wave in a forward direction of the vehicle and receives a reflected electromagnetic wave thereof for detection of a remote obstacle. The system includes a vehicle speed sensor is provided for sensing a speed of the vehicle.

Abstract: A system for monitoring operation and location of a first moving vehicle relative to a second moving vehicle. A minimum separation distance between the first and second vehicles is estimated, based on the first vehicle velocity, and optionally on the second vehicle velocity, using location determination (LD) signals received from satellite-based transmitters from GPS, GLONASS and LEO satellites, or from ground-based signal sources such as LORAN signal towers, and using ranging signals from SONAR, RADAR or a similar system. The minimum separation distance is compared with the actual separation distance at selected times, and a vehicle driver is advised if the actual separation distance is too small, if the separation distance is decreasing too quickly, or if the second vehicle velocity is decreasing too quickly. The second vehicle may travel in the same traffic lane, in an adjacent lane, or on a road that intersects the road used by the first vehicle.

Abstract: When the behavior of a vehicle becomes unstable during an automatic braking operation for avoiding contact of the vehicle with an object, the restoring of the unstable state backed up to effectively avoid the contact of the vehicle with the object. When a radar device in the vehicle, detects the object exist ahead of the vehicle in the direction of movement of the vehicle, the possibility of the contact of the vehicle with the object is determined by a determining device from the relative positional relationship between the vehicle and the object, based on the result of the detection. When it is determined that there is the possibility of the contact, an automatic braking device operates a vacuum booster to carry out an automatic braking operation.

Abstract: A sensor system for detecting impacts to a vehicle, allowing for actuation decisions of passive restraint devices. The sensor system includes one or more piezoelectric sensor assemblies (42), each including a coaxial piezoelectric cable (44) contained within a tube housing (54), which is mounted to a structural member of the vehicle. The sensor system may also include accelerometers (36, 38) that are also in communication with the restraints control module (40) and employed in combination with one or more piezoelectric sensor assemblies (42). Further, the sensor system may include diagnostics for monitoring one or more of the sensor assemblies (42) in order to detect a sensor failure, while not interfering with the impact signals from the sensor assemblies (42).

Abstract: A driver alertness monitoring system for motor vehicles which issues visual or audible signals to the driver, and which monitors visual, audible or mechanical responses received from the driver to determine driver alertness. An electronic control unit, preferably incorporated in the circuitry of existent vehicle safety systems, controls the activation of these visual or audible signals and determines appropriate actions based on the response of the driver. The system includes auxiliary sensors which can be used to control and modify the function of the system to reduce unnecessary activation.

Abstract: A method and an apparatus based thereon are described for the automatic recognition of whether, in a traffic situation or in a traffic environment, vehicles are driving on the right or on the left. Said method is used in a motor vehicle as part of adaptive speed control. The prevailing direction of traffic flow is determined on the basis of other vehicles, which are traveling toward the cited vehicle. For this purpose, a frequency distribution is created as a function of a lateral, preferably directional distance y; a center of gravity S of this frequency is determined; and then it is determined on what side of the controlled vehicle this center of gravity S is located.

Abstract: A short ring is mounted onto a back part of a housing of an ultrasonic sensor so that the short ring is coaxial with the housing. The width of the short ring along the axial direction of the housing is set such that it shields the back part of the housing including a transformer of a processor. The short ring is made up of an excellent metal conductor and is coaxial with the coils of the transformer.

Abstract: A system for monitoring operation and location of a moving first vehicle relative to a second vehicle. A minimum separation distance between the first and second vehicles is estimated, based on the first vehicle velocity, and optionally on the second vehicle velocity, using location determination (LD) signals received from satellite-based transmitters from GPS, GLONASS and LEO satellites, or from ground-based signal sources such as LORAN signal towers, and using ranging signals from SONAR, RADAR or a similar system. The minimum separation distance is compared with the actual separation distance at selected times, and a vehicle driver is advised if the actual separation distance is too small, if the separation distance is decreasing too quickly, or if the second vehicle velocity is decreasing too quickly. The second vehicle may travel in the same traffic lane, in an adjacent lane, or on a road that intersects the road used by the first vehicle.

Abstract: The detection region to which the electromagnetic wave from a vehicle is transmitted ahead in a direction of movement of the vehicle in order to detect an obstacle such as another vehicle in front or the like, is composed of a first detection region looking slightly upward with respect to the road surface and a second detection region looking slightly downward with respect to the road surface. Received signal strengths of reflected waves in the first and second detection regions are compared with each other. When the two received signal strengths are substantially equal to each other, the vertical angle of the object detecting apparatus is judged adequate. When the received signal strength of the reflected wave in the upper-side, first detection region is larger, the angle is judged downward.

Abstract: A scan-type radar apparatus for a vehicle which determines whether an object detected by the radar exists in the lane in which the radar equipped vehicle is moving with a high accuracy while restricting an increase of the manufacturing cost of the radar apparatus. A scan-type radar detects objects existing in a detectable range, the scan-type radar apparatus assuming a vehicle moving lane area corresponding to a vehicle moving lane in which the vehicle is moving based on an operating condition of the vehicle, the vehicle moving lane area being assumed within the detectable range. An actual direction of each of the objects is detected by the scan-type radar with respect to the radar equipped vehicle.

Abstract: A device for determining the distance between the rear of a trailer and a loading dock is disclosed which assists a driver backing the trailer up to the loading dock by visually and continuously letting the driver know how close the rear of the trailer is to the loading dock, thereby providing information to prevent the rear of the trailer from colliding with the loading dock. The distance between the back of the trailer and the loading dock is determined by an ultrasonic transducer which is mounted onto the side of the loading dock toward which the rear of the trailer will be backed. A display module mounted on the loading dock provides a numeric indication of the distance between the rear of the trailer and the loading dock.

Abstract: A new object sensing device for a vehicle for alerting a driver of a vehicle while backing up of an object or obstruction that is close to the vehicle. The inventive device includes a mounting frame which is mountable to a license plate of a vehicle. A transmitter for transmitting a signal is provided on the mounting frame. Also provided on the mounting frame is a receiver for receiving a signal transmitted from the transmitter and reflected off of an object towards the receiver. A control panel is operatively connected to the receiver. The control panel has a plurality of indicators for indicating to a user a reflect signal received by the receiver. The control panel is mountable in the interior of a vehicle.

Abstract: The present invention, generally speaking, provides an acoustic railway crossing detector. The present invention provides a means of not only detecting the presence of a train, but it can determine speed and direction of travel. This allows a more adaptive control of the railway crossing gates and may reduce the nuisance factor of having the gate close too far in advance of the train reaching the crossing. It is also much less susceptible to false activation by natural causes or acts of vandalism. In accordance with one embodiment of the invention, an acoustic railway crossing detector includes at least one acoustic emitter; at least one acoustic detector; multiple reflectors arranged to reflect acoustic energy produced by an acoustic emitter toward an acoustic detector, and control circuitry coupled to an acoustic detector for producing an indication of whether or not a train is present.

Abstract: Proximity radar mounted in a vehicle determines the location of other vehicles. Other vehicles detect their own positions and broadcast those positions to all surrounding vehicles. Vehicle position data is plotted on a moving map so the driver can see the location of other vehicles, in some cases with an icon color which matches vehicle color(s). A driver can open a communication link with drivers who are projected to constitute a collision threat. A fixed radar unit can be positioned at blind intersections and broadcast vehicle location information for vehicles not equipped with the ability to track their own locations.

Abstract: A method of reducing the travelling speed of a vehicle which has a multi-cylinder, piston-type internal-combustion engine, a variably controllable valve drive and a collision avoidance system includes the following steps: continuously determining, by the collision avoidance system, an actual distance between the vehicle and a vehicle ahead and comparing the actual distance with a speed-dependent minimum safe distance; and braking the vehicle by switching over at least one of the engine cylinders to a compressor operation when the actual distance falls below a minimum safe distance.

Abstract: In a procedure for non-contact distance measurement, in particular to measure the distance from obstacles in the immediate vicinity of motor vehicles, measurements are made using a first measuring procedure, and in a first measuring range absolute values of the respective distance are determined. Using a second measuring procedure, relative values are determined in a second measuring range that overlaps the first. Absolute values of the first measuring procedure, which lie inside the overlapping range, are used to calibrate the relative values of the second measuring procedure.

Abstract: In a first distance range to the obstacle, the velocity of the vehicle is limited by the control of the power of the drive unit of the vehicle. In a second distance range which is less than said first distance range, the braking force at the wheel brakes is built up.

Abstract: An optical path degradation detecting device having a laser distance detector which uses a laser beam to detect the distance between two objects and which generates distance signals representative of the distance between the two objects. A first predetermined point signal is generated upon the distance signals being in a distance representative of a first predetermined distance or less, and a second predetermined point signal is generated upon the distance signals being in a distance representative of a second predetermined distance or less, wherein the second predetermined distance is less than the first predetermined distance. A fault signal is generated if the second predetermined point signal is generated within a predetermined time interval relative to the generation of the first predetermined point signal.

Abstract: A vehicle exterior object detector apparatus includes a transmitter and receiver carried within a housing and mounted by a holder to a support on the vehicle. A heater element is carried in the holder in surrounding relationship with one end of the transmitter and receiver housing for melting ice and snow build up on the end of the housing for proper operation of the transmitter and receiver.

Abstract: A system for preventing rear end collisions is provided including a warning light housing with a transparent panel mounted to a rear of the vehicle. A distance detector is directed toward a rear of the vehicle. The distance detector is adapted to detect a distance from a following car. A bulb is provided for illuminating upon the actuation thereof. Finally, control circuitry is connected between the distance detector, bulb, a speedometer, and a battery of the vehicle. The control circuitry is adapted for receiving a speed of the vehicle from the speedometer and further to calculate a distance per speed value, whereby the control circuitry actuates the bulb only upon the distance per speed value being lower than a predetermined value.

Abstract: A car obstacle monitoring system which will not erroneously detect a distant obstacle as an obstacle around a car and can avoid an erroneous detection by relatively simple control even though it is arranged so as to emit ultrasonic waves of a single frequency. A control circuit 12 controls a right sonar 1, a left sonar 4 and center sonars 2 and 3 provided on the right side, on the left side and at the center of a car 5, respectively. The control circuit 12 has a timing element and a discriminating element. The timing element generates three emission modes including a first emission mode in which the right sonar 1 and the sonar 3 emit ultrasonic waves in synchronism, a second emission mode in which the left sonar 4 and the center sonar 2 emit ultrasonic waves in synchronism, and a third emission mode in which the right sonar 1 and the left sonar 4 emit ultrasonic waves in synchronism repeatedly without overlapping each other.

Abstract: An object detection assembly and method use at least one sensor to detect a signal indicating the presence and location of an object relative to an automotive vehicle. A receiver receives a location signal created by a transmitter. A control unit receives the location signal and identifies the presence and degree of closeness of the object by activating audible and visual indicators. The control unit operates a parameter definer to identify the spatial parameters within which a warning of the existence of the object is to be activated. The control unit receives signals of vehicle speed and transmission state to determine the spatial parameters.

Abstract: A backup aid system, for a vehicle, senses when the vehicle is in reverse gear. Ultrasonic sensors at the rear of the vehicle provide continuous range information to a control module for objects that are detected as being relatively close to the vehicle. A radar system provides range information to the control module for objects detected beyond the range of the ultrasonic system. At low speeds below a predetermined minimum speed level or when the system is placed in the "park" mode for parking, the radar information is ignored and only the ultrasonic information is used to warn the vehicle operator. At a relatively high threshold backup speed, the vehicle operator is immediately warned to slow down, whether or not an object is detected in the vehicle path. Between the lower and upper threshold speeds, both the ultrasonic system and the radar system are used to continuously range and detect any objects that enter their respective detection fields.

Abstract: As provided here, an obstacle warning system for a vehicle is capable of issuing an alarm accurately according to the curved state of a road. When the road is curved, the system sets the correction time counter on the basis of the following conditions: whether or not the curvature radius of the curved road is small; whether or not a guardrail is detected immediately ahead of the vehicle; whether or not an erroneously-recognized object, such as a set of guardrail reflectors exhibiting large relative acceleration is immediately ahead of the vehicle; and whether or not the number of obstacles recognized reaches a value indicating that the vehicle is approaching a curved section of the road. When a stationary object enters the field of view indicating that there is a possibility of a collision, the obstacle warning system corrects the warning distance in response to the value of the correction time counter, thus making it possible to avoid a false alarm during cornering.

Abstract: Side detection radar utilized on a host vehicle for covering a blind spot in a vehicle mirror view produces alert commands resulting in signals which have gaps due to poor radar reflectivity of portions of a target. To fill these gaps to produce a steady alert signal when a target vehicle is in radar view and to extend the perceived zone of coverage, a variable sustain time is added to each alert signal which exceeds a threshold value. The sustain time varies as an inverse function of the relative vehicle speed and the threshold value varies as an inverse function of vehicle speed. If the alert signal is shorter than the threshold value, then a minimized hold time can be applied.

Abstract: In a vehicle collision preventing system, a possibility of collision of a subject vehicle against an object ahead of the subject vehicle is determined at least based on values measured by a distance measuring unit for measuring longitudinal and lateral distances between the subject vehicle and the object and a value detected by a subject-vehicle speed detecting device, an actuator is operated in accordance with the result of such determination to avoid the collision. A lateral relative distance of the subject vehicle and the object is calculated by a lateral relative distance calculating device based on the values measured in the distance measuring unit. Any of a judge level in the judgment of the collision possibility in a judging device or operation levels of actuators is changed in accordance with the result of the determination in a collision avoidance level determining device based on the lateral relative distance.

Abstract: The invention provides a process and apparatus for the detection of obstacles by means of ultrasound waves having an enhanced ability to distinguish between echoes caused by obstacles and those caused by interference signals. Ultrasound pulses are emitted by an ultrasound transmitter unit, and are received by an associated ultrasound receiver unit. (A plurality of such transmitters and receives may also be used.) Ultrasound echoes detected by the receiver units are used to form echograms in which detected echoes are projected. The echogram thus measured is used to generate an analysis echogram, based on information contained in the measured echograms. In particular, the most recent analysis echogram is modified depending on the size and location of echoes contained in the measured echogram. Signals contained in the analysis echogram are then compared with predetermined threshold values to distinguish between echoes reflected from obstacles and echoes due to interference.

Abstract: A collision avoidance detector including a transceiver installed in a rear portion of a leading vehicle operative to transmit a signal to and receive a reflected signal from a trailing vehicle, a processor operative to process the signals and derive therefrom information concerning a safe distance criterion between the leading and trailing vehicles and an alarm device, wherein the processor actuates the alarm device if the safe distance criterion is not met.

Abstract: A distance control apparatus for a vehicle detects a vehicle speed and a distance to a preceding vehicle through a vehicle speed sensor and a distance measuring device. The distance control apparatus calculates two deceleration distances by a driver model calculating device and a vehicle model calculating device. The driver model calculating device calculates the deceleration distance on the basis of the vehicle speed and the distance to a preceding vehicle and with reference to a driver's control characteristics. The vehicle calculating device calculates the deceleration distance on the basis of the vehicle speed and with reference to physical characteristics of the vehicle.

Abstract: An automotive rear detection system which assists a driver by informing whether an obstacle is present when the vehicle is in a reverse motion. The alarm is activated by transmitting an audible noise to warn the driver. The signals are monitored by detectors which uses frequency modulation current wave mode to recognize whether objects are present within approximately eight feet regardless if it is in motion or not. The detectors send a signal to a control box mounted inside the vehicle which activates the alarm.

Abstract: An apparatus for and a method of preventing a car from coming into collision with an object car running ahead or behind, by monitoring car running conditions in the front and rear of the car by the provision of front and rear sensors to give an alarm to the front and rear object cars when an emergency situation has monitored, sensing a slope of a road surface on which the car runs to remove an error caused by an inclination of the car, sensing a handle rotation of the car to enable the car to follow the front object car on a curved road and to be informed of situations in the front and rear of the car on the curved road, establishing a sufficient safety distance, and sensing an emergency situation occurring in the rear of the car to inform a driver of the rear object car of the emergency situation by the provision of a display.

Abstract: A vehicular safety distance alarm system for monitoring a travelling distance between a source vehicle and a target vehicle and activating an alarm when a predetermined safety distance defined between the two for a given speed is compromised comprising a distance measurement mechanism coupled to a source vehicle for determining and transmitting a distance signal representing a travelling distance between the source vehicle and a remote target vehicle; a selection mechanism coupled to the source vehicle for allowing a driver to select a desired range of safety distances expressed as a function of source vehicle velocity and a set time to reach a target vehicle; an alarm signal generation mechanism coupled to the distance measurement mechanism and selection mechanism for comparing the distance signal to a safety distance at a given source vehicle velocity and transmitting an alarm signal when the safety distance is compromised; and an alarm mechanism coupled to the alarm signal generation mechanism for providin

Abstract: A circuit arrangement determines a distance of a motor vehicle from an obstacle in a near range by a displacement sensor instead of an ultrasonic measurement. The distance is determined, above a predetermined limiting value, in accordance with the known ultrasonic transit time measurement. In this range, by comparing the signals of the displacement sensor with the ultrasonic measurement a calibration can be carried out and a correction factor for the displacement sensor can be formed. The correction factor is taken into account during the measurement in the near range, as is the contour of the vehicle.

Abstract: A warning system for a vehicle has a warning device for issuing a warning when the vehicle approaches an object. A warning timing parameter section detects a driving operation by the driver of the vehicle, and calculates a reaction time from the time a warning is issued by the warning device to the time the driver starts the driving operation in response to the warning. A warning control section controls the timing at which the warning should be issued by the warning device, based on the calculated reaction time.

Abstract: Car collision prevention apparatus and method comprises a slave processor for transmitting and receiving a laser beam or an ultrasonic wave signal to extract distance information between a car and a car in front, and a master processor for comparing the extracted distance information from the slave processor with a safety distance between the car and the front car based on a car speed and performing car accelerating or decelerating and alarm functions in accordance with the compared result. The slave processor comprises a long-distance sensing laser sensor and a short-distance sensing ultrasonic wave sensor disposed in a front side of the car, the long-distance sensing laser sensor consisting of a laser trigger circuit, a laser transmitter and a laser receiver, the short-distance sensing ultrasonic wave sensor consisting of an ultrasonic wave trigger circuit, an ultrasonic wave transmitter and an ultrasonic wave receiver.

Abstract: A vehicle bind spot detector, comprising ultrasound transmitters and receivers deployed on both sides of a vehicle, for continuously, simultaneously, monitoring for dangerous road situations due to vehicles present in dead area open space in angles .beta.1 and .beta.2, on left and right sides of the vehicle, which areas are outside of a driver's field of view, hence in the vehicle blind spots. The vehicle blind spot detector includes capability of individualizing the ultrasound signals used in the detection of vehicles in the blind spots, thus preventing interference between blind spot detectors installed in adjacent vehicles.

Abstract: An electronic obstacle detection system for guiding and warning a motorist of obstacles in the detection area while backing-up. The main components of the system include a pair of sensor clusters to be affixed to the rear of the vehicle, a pair of exterior visual indicators, and an audio-visual indicator located in the vehicle. Each of the sensor clusters are encased in a housing having angled, stepped portions configured to provide complete area coverage of transmitted and received signals.

Abstract: A short range ultrasonic distance warning system is used as a parking aid in a motor vehicle. The entire system is active in the case of reverse gear being selected and low speed, and is deactivated automatically at higher speed. If reverse gear is not being selected, only the system part for front space monitoring is active at low speed of travel, while the system is once again automatically kept inactivated at higher speed. This implements a parking aid which is convenient and avoids unnecessary system activations.

Abstract: A method of alerting marine mammals and other mammals underwater to the danger of approaching motor vessels includes generating a pulsed acoustical signal at a predetermined source frequency and at a fixed or variable (with boat speed) sound pressure level and projecting the generated signal underwater in a highly directional manner from a motor vessel and in a direction corresponding with the direction of travel of the motor vessel or from fixed hazards which present a danger to mammals underwater; the projected pulsed acoustical signal having an underwater frequency ranging between 3 kHz and 26 kHz.