Abstract: A distance sensing device for a motor vehicle, positioned at the rear of the motor vehicle, for sensing a distance to an obstacle to the rear of the motor vehicle, has a brake light unit positioned in the interior of the motor vehicle at the rear window. At least one sensor for sensing the distance is provided. An optical display unit located within the brake light unit is provided, and the at least one sensor is connected to the optical display unit.

Abstract: A transducer assembly for a proximity sensor which comprises an elongated polymer piezoelectric film (16). The film is supported as an elongated series of arcuate segments which are curved in the same direction and have the same radius of curvature. Electrodes (18) on both sides of the piezoelectric film form opposed pairs, each pair being associated with a respective arcuate segment. The electrodes are utilized for applying a varying electric field across the thickness of the film to cause an ultrasonic acoustic wave to be radiated from the film.

Abstract: A phased array based radar and vehicular safety warning system for collision avoidance, including a phased array based radar, a controlling processor, and a warning system that also provides a warning to the driver of the equipped vehicle as well as drivers of other, non-equipped automobiles involved in an unsafe driving condition. The phased array radar includes a flexible antenna array that may be mounted conformally on existing automobiles without detracting from their design curvature. In one embodiment a pair of phased array radar antenna may be oriented towards opposing sides of an equipped automobile to provide warning surveillance of vehicles laterally approaching the equipped auto from the sides. In another embodiment a phased array radar antenna is oriented to the rear of the equipped automobile to provide warning surveillance of vehicles following the equipped auto too closely, and for warning of unsafe lane changes.

Abstract: A stereophonic warning apparatus for a vehicle is provided with a judging device which judges warning priority level relative to an object around the vehicle according to signals from radars for detecting the object and a vehicle behavior detecting device. A control device controls the output level of a plurality of speakers in a passenger compartment of the vehicle according to the position of the detected object such that the speakers output a warning sound to form a sound image at a position to which the detected object is located, while changing the warning sound according to the warning priority level.

Abstract: A warning apparatus for a vehicle generates a warning for a driver of the vehicle when the separation between the vehicle and an obstacle located in front of the vehicle falls below a prescribed value. The prescribed value is varied in accordance with changes in the physical or mental state of the driver of the vehicle, environmental conditions, or the driving characteristics of the driver and thereby adjust to changes in the driver's reaction time and the stopping distance of the vehicle.

Abstract: A system for providing advance warning of underwater navigation hazards that threaten safe ship passage is provided. The system includes a sonar transmitter/receiver adapted for mounting on the ship in a forward looking direction. A processor, in response to sonar returns produced by the sonar transmitter/receiver, produces a sonar produced slope profile of a region of the sea bottom in front of the path of the vessel. A memory stores a slope profile of the region of the sea bottom in front of the vessel, such profile being developed from charted depth data. The stored charted depth data developed slope profile is compared with the sonar return produced slope profile to determine whether the sonar produced slope profile and the charted depth data slope profile are consistent with each other.

Abstract: A distance measuring system includes a device for detecting ringing signals (false echoes) generated by ultrasonic transducers used to generate probe signals and detect echoes of the probe signals to determine the distance of an external object from the measurement system. The absence or duration of ringing signals are determined, and the display of the distance measuring system is operated accordingly. False indications of distance measurements are limited by storing a number of distance measurements in a memory, and selecting the measurement most likely to indicate the presence of an object from which the distance to the measuring system is determined.

Abstract: A method and apparatus for detecting objects around a vehicle, comprising a plurality of microwave-transceiver sensors for transmitting microwave signals to reflect off objects around the vehicle. The reflected signals are received and passed to a control unit for comparing the received signal to a transmitted signal to determine whether a detected object constitutes a threat to the moving vehicle. An alarm means is connected to the control unit and activates upon the receipt of an alarm signal when the control unit determines a detected object constitutes a threat to the vehicle.

Abstract: An apparatus for alerting the driver of a vehicle to the presence of another vehicle in an adjacent lane while changing lanes, in which an ultrasonic transmitter emits acoustic energy which, if reflected from an adjacent vehicle within a zone of coverage, is received on an ultrasonic receiver and processed to produce an audible warning to the driver indicative of the relative speed and position of the adjacent vehicle. One of three distinct audible warning tones alerts the driver to an approaching vehicle, a receding vehicle, or a vehicle whose relative speed is the same.

Abstract: A time-of-flight range sensing system for a vehicle such as a mobile robot comprised of a number of sensors that are situated at preset locations and aligned with particular orientations on the vehicle. Each sensor may consist of single or multiple transmitting transducers and single or multiple receiving transducers. Each sensor provides a means for changing the effective sensing volume of the sensors or it has two or more separate processing channels for processing the time-of-flight information with several different effective sensing volumes using the sensor signal processor. The sensor signal processor also provides a means for collecting information regarding the echo signal peak value and the noise present in the received signal before reception of the first echo.

Abstract: A system for providing advance warning of underwater navigation hazards that threaten safe ship passage is provided. The system includes a sonar transmitter/receiver adapted for mounting on the ship in a forward looking direction. A processor, in response to sonar returns produced by the sonar transmitter/receiver, produces a sonar produced slope profile of a region of the sea bottom in front of the path of the vessel. A memory stores a slope profile of the region of the sea bottom in front of the vessel, such profile being developed from charted depth data. The stored charted depth data developed slope profile is compared with the sonar return produced slope profile to determine whether the sonar produced slope profile and the charted depth data slope profile are consistent with each other.

Abstract: A device to warn a ship crew of submerged objects in their immediate vicinity, combined with alarm and logging facilities. The device is composed of one or more sonic or ultra sonic transducers placed aboard the ship, with coverage arranged so as to give surrounding "envelope" to the sides and to the area ahead of the vessel, as well as some predetermined downward looking angle. The transducer or transducers are connected to an electronic distance measuring device that will measure distance to possible obstacles, similar to conventional sonar techniques. The measurements in each direction are compared by an electronic processor against a table of minimum distances, and if the distance falls below the predetermined value for a given direction, an alarm is activated. In addition, all alarms, cancellations of alarms, activation and deactivation of the system are logged automatically with an identification of the operator.

Abstract: A vehicular distance measuring system includes a distance measuring device for detecting a distance to an object and, in response, supplying a distance signal. An ultrasonic transducer mounted in a vehicle taillight or running light assembly is used to ultrasonically detect and range objects in back of, and along side a vehicle in which the system is installed. A display includes (i) a vehicular mirror having an image reflecting surface with a transparent window portion located therein, and (ii) a digital display mounted on the vehicular mirror and viewable through the window portion. The digital display is responsive to the distance signal for displaying the detected distance to the object. The distance measuring device includes a comparator for comparing the distance to the object with a predetermined threshold distance and, in response, supplying a display unblank signal.

Abstract: The collision avoidance system includes structure mountable at the side mirror position of a vehicle. The system includes a rotatable mirror and an ultrasonic transmitting and receiving unit which is adaptable to scan a predetermined area about the vehicle to detect the presence of an object and to calculate its distance from the vehicle. If the distance and speed are determined to pose a threat, the distance is placed on a display and an alarm is sounded. Two displays are provided, one for the forward end of the vehicle and another for the rear end of the vehicle. The system operates when the vehicle is moving forwardly and rearwardly. Also, when the vehicle is not moving, the presence of a potential intruder is also monitored and the system can actuate an anti-theft alarm of the vehicle. Further, the system can be programmed by a plurality of operators to particular distances, with the system discerning which operator is driving and automatically using that operator's input.

Abstract: An object detecting apparatus for use in automobile is disclosed, and the apparatus includes ultrasonic wave transmitting and receiving units installed at a certain interval. Internally, the apparatus is provided with a single circuit which is capable of performing a functing of maintaining the safety distance with the car following behind during the normal running of the automobile, a function of detecting objects appearing behind during a reverse driving, and a function of making an exact close parking by reverse advancing. The circuit is divided into three sections: and ultrasonic wave transmitting section, a reflected wave receiving section, and a control device.

Abstract: This invention provides a vehicular proximity sensing system having a plurality of preferably utrasonic distance-detector devices disposed around the vehicle's periphery and connected with a simulated vehicle display on the dashboard which display includes visual means to alert the driver to the close approach of an external object to the vehicle, in which the distance-detector devices use a coded signal characteristic of the vehicle and recognizable by the system, so as to distinguish reflections from interfering signals from other vehicles. In a preferred embodiment, the simulated vehicle display is provided with tricolor LED warning devices, wired to a computer or a box holding the LED's, and these can be illuminated by optical fibres and a vehicle representation is illuminated by a luminescent panel. A valuable option is a remote and an externally audible warning device enabling a parked vehicle to be provided with defensive means against being hit by another vehicle.

Abstract: A system and method for detecting the presence of objects in the path of the end portion of a movable vehicle are disclosed. A vehicle mounted transmitter transmits bursts of ultrasonic object detection signals. A receiver also mounted on the vehicle receives not only a direct signal from the transmitter, but also signals reflected from objects in the path of the movable vehicle. The transmitter and receiver are mounted on the end portion of the vehicle so that they constitute the foci of an elliptical path defining the loci of all points of signal reflection having the same total transit time of signal from the transmitter to a reflecting object and back to the receiver. The elliptical path of the loci of the closest detectable objects preferably encompasses substantially the entire end portion of the movable vehicle.

Abstract: Disclosed is a sonar for avoiding sub-surface underwater objects, for a surface vessel, having its directivity in elevation optimized to observe the surface and its surface reverberation reduced to the minimum. It consists in using an acoustic antenna having two columns of n transducers, the first column insonifying, at transmission, an elevation sector corresponding to the collision-risk zone and forming channels at reception, in the insonified elevation sector, the width of the channels being all the finer as the desired precision of the measurement of the position in elevation is high. The second column is necessary for the localization in relative bearing. The disclosure can be applied to the precise localization in elevation of objects located in the path of a vessel.

Abstract: The ultrasonic device which is sensitive to a selectably defined range for giving warning to a vehicle operator while backing which indicates visually an obstruction substantially out of range, close to range and within range coupled with an in range audio alarm giving an intermittent tone at a defined pulse rate which rate approaches non-pulsating as the object approaches within 25% of the selected range. A convex reflector of a defined radius in conjunction with angularly upright baffles disposed on the convexity is coupled to the transmitting/receiving transducer to generate an ultrasonic beam which encompasses objects anywhere in the range area adjacent to the vehicle's rear edge.

Abstract: The space ahead of a moving vehicle is irradiated in sectors (A-G) by a plurality of CW solid state radar devices mounted as an array across the front of the vehicle, such that adjacent lobes of each beam may overlap. The radar signal comprises a CW beam modulated intermittently by a slightly offset frequency to produce `pulses` which when reflected from obstacles within respective sectors (A-G) are detected by mixer diodes in one, or two adjacent radar devices after a time delay which, measured, yields a distance to the obstacle. Obstacles so detected may be displayed in two dimensions within their respective sector (A-G) on a display projected onto the windscreen.

Abstract: A method and apparatus for presenting elevation angle information with rect to overhanging objects to an operator of a submersible incorporates a substantial portion of the sonar equipment found onboard conventional submersibles. Reflections of radiant energy from the objects are received by a highly directional array of hydrophones. The received reflections are time varying gain attenuated to substantially compensate for range-dependent signal variations such as are due to changes in scattering areas, spreading loss and attenuation loss. Using time varying gain processing and by taking into account the known directivity pattern of the hydrophones, the received reflections are reduced to represent signal characteristics due substantially to the elevation angle of the incoming reflections. These modulated reflections are quantized by first sorting the reflections into bands according to amplitude intensity and then by assigning a distinct color to the individual bands.

Abstract: A driver alerting device includes a transceiver adapted for mounting at the rearward end of a vehicle for directing its wave output rearwardly of the vehicle. Return wave signals for many objects within the transceiver range are picked up and supplied to the transceiver by an antenna. Any resultant doppler shift signal is amplified for driving an audio alarm adapted for placement within the passenger compartment of the vehicle. The circuit is adapted for electrical connection to the back-up light circuit of the vehicle for activation only when the vehicle transmission is engaged in reverse gear.

Abstract: A driver alerting device includes a transceiver adapted for mounting at the rearward end of a vehicle for directing its wave output rearwardly of the vehicle. Return wave signals for many objects within the transceiver range are picked up and supplied to the transceiver by an antenna. Any resultant doppler shift signal is amplified for driving an audio alarm adapted for placement within the passenger compartment of the vehicle. The circuit is adapted for electrical connection to the back-up light circuit of the vehicle for activation only when the vehicle transmission is engaged in reverse gear.

Abstract: A microprocessor-based ultrasonic intrusion detection system includes an initialization mode wherein a plurality of echoes are cumulatively processed to produce a reference or signature data set representing the area to be monitored without intruding objects. Later received echoes are compared to this signature so that an intruding object will cause generation of an alarm signal. Time varying thresholds are utilized to compensate for attenuation caused by increased distance.

Abstract: A motor vehicle backup monitor introduces a reflector into the detection range of a sensor in predetermined manner during a test phase. The reflector can comprise, for example, the flap of the housing which encloses the sensor. The reflector is removed from the detection range of the sensor during its operational phase. The monitor unit is particularly applicable to ultrasonic sensors used to monitor a motor vehicle when it is backing up.

Abstract: A loading dock range finding system is provided for permitting a driver of a vehicle backing towards a loading dock to determine a distance of the back end of the vehicle from a reference point at the loading dock. An ultrasonic transmitting and receiving transducer is positioned adjacent the loading dock for sending signals towards a back end of the truck, which are reflected and received by the transducer. A display unit is connected to the transducer and is mounted at a location adjacent the loading dock so that a visual display on the display unit can be easily viewed by a driver of the vehicle looking through his rear view mirror. A distance between the back end of the vehicle and the reference point is displayed in reversed image fashion on the visual display so that when the driver views the image through his rear view mirror, it is not a reversed image.

Abstract: An unmanned movable and steerable vehicle has a device for locating obstacles in relation to a coordinate system which moves along with the vehicle. Ultrasonic waves transmitted by transmitters on the vehicle in the driving direction thereof and ultrasonic waves reflected back to the vehicle by obstacles and received by receivers on the vehicle produce information whereby vehicle steering and/or braking signals function to prevent a collision. For the purpose of an interference-free, accurate location determination of an obstacle in relation to the coordinate system moved along with an unmanned movable and steerable vehicle, a single pulse is transmitted by two adjacent ultrasonic waves and also received again at the transmission sources. In a progression by one another sound source, after the first sound source has been switched off, the same procedure of transmitting a single pulse and, in the presence of an obstacle, the reception of a reflected ultrasonic echo is possible.

Abstract: A method and apparatus is provided for alerting the operator of a vehicle as to the distance from the rear of the vehicle to a structure such as a loading dock to which the vehicle is being backed through the utilization of sonar ranging and means for converting a detected range into an audible call out of the distance from the back of the vehicle to the structure to which the vehicle is being backed. In one embodiment the talking unit is activated upon the placing of the vehicle in reverse gear. When used on trucks, the transducer is removably mountable to the rear of the truck, with a transmission line lead to the cab of the truck. In the preferred embodiment, a 50 kH.sub.

Abstract: An ultrasonic anti-collision detection and warning system adapted to be attached to a corner for warning objects approaching an intersection.

Abstract: A method of and a device for safeguarding a vehicle or machinery movable in space, such as a robot, a stacker, an operatorless transporting vehicle or the like against collision, in which by the use of distance sensors, especially ultrasonic sensors with echo time measurement, the distance from an obstacle is measured and a reaction signal is initiated when a preset threshold value is not reached, said method and device being characterized by a time-synchronous actuation of the distance sensors in a compound circuit which in case of a dangerous approach of the vehicle to an obstacle triggers a reaction signal which is either a speed reduction signal or a stop signal. Moreover, the measuring signal can be utilized as a command signal for actively influencing the vehicle movement, e.g. for driving around the obstacle or the like.

Abstract: A monitoring apparatus for a safety device for driving a vehicle in reverse comprising at least two transmitter/receiver pairs which are mounted at the back of the vehicle and which operate by reflecting sound. Each transmitter/receiver is associated with an electroacoustic transducer. An acoustic shunt is positioned between neighboring transducers. The transmitter/receiver pairs alternate cyclically to acquire an object. The signal received from a neighboring transmitter is evaluated as a function control signal.

Abstract: A driver alerting device includes a transceiver adapted for mounting at the rearward end of a vehicle for directing its wave output rearwardly of the vehicle. Return wave signals for many objects within the transceiver range are picked up and supplied to the transceiver by an antenna. Any resultant doppler shift signal is amplified for driving an audio alarm adapted for placement within the passenger compartment of the vehicle. The doppler shift signal also activates a solenoid which applies the air brakes of the vehicle. The circuit is adapted for operative electrical connection to the vehicle transmission or the like for activation only when the vehicle transmission is engaged in reverse gear.

Abstract: A driver alerting device includes a transceiver adapted for mounting at the rearward end of a vehicle for directing its wave output rearwardly of the vehicle. Return wave signals for many objects within the transceiver range are picked up and supplied to the transceiver by an antenna. Any resultant doppler shift signal is amplified for driving an audio alarm adapted for placement within the passenger compartment of the vehicle. The circuit is adapted for electrical connection to the back-up light circuit of the vehicle for activation only when the vehicle transmission is engaged in reverse gear.

Abstract: An improved ultrasonic ranging device having a ultrasonic sensor unit provided for detecting the distance between a ground object and a rear end of a vehicle includes: a casing body composed of a front casing and a rear casing with a round opening formed in the opposing ends; a control unit with a plurality of microswitches and a control circuit installed at one end of the casing body and electrically connected to the ultrasonic sensor unit; a gear system with a motor and a reduction gear member disposed at another end of the casing body and electrically connected to the control circuit; and a protective cover with a transmission arrangement movably connected to the casing body with the transmission arrangement meshed with the reduction gear and the control unit; thereby, the protective cover can be automatically raised up and lowered down along with the backward and forward movements of a vehicle for protecting the ultrasonic ranging device against water, dust and mud.

Abstract: A non-contact collision avoidance system for an automatically guided vehicle is disclosed for preventing collisions between the vehicle and obstacles in the path of the vehicle during vehicle maneuvers, including relatively sharp turns. A sensor device mounted on the vehicle provides panoramic sensing of obstacles in the path of the vehicle. The field of view of the sensor device is altered as a function of the vehicle steering angle. Also disclosed is a steering angle sensor comprising an optical shutter system for providing a signal representing the steering angle of the vehicle.

Abstract: An alarm device for a construction vehicle including a transceiver adapted for mounting at the rearward end of a vehicle for directing its wave output rearwardly of the vehicle. Return wave signals for many objects within the transceiver range are picked up and supplied to the transceiver by an antenna. Any resultant doppler shift signal is amplified for driving an audio alarm positioned on the vehicle. The circuit is adapted for electrical connection to the reverse gear of the vehicle for activation only when the vehicle transmission is engaged in reverse gear.

Abstract: A range control system positioned within a stationary housing comprising: a pulse oscillator for providing a clock signal; and a transmitter receiver circuit that directionally transmits an acoustic pulse signal to a target and receives an echo from the target to provide an amplified echo signal. A timing circuit means is included for providing a range gate signal characterized to start with each clock signal and to have a predetermined duration characterized to provide a time for the acoustic pulse to travel to the target and for the echo to return from the target. An alarm signal is provided to indicate that an echo signal is being received prior to the termination of the range gate signal. A ring blanking gate signal source provides a ring blanking gate signal commencing with each clock signal and having a duration longer than the tailoff ringing of the acoustic pulse. A diode clamp is coupled to the transducer drive circuit echo signal output.

Abstract: An ultrasonic sensor system particularly for automatic door openers of a swinging door type, in addition to sensors (14) for people approaching a door for controlling opening and closing purposes, has at least three microprocessor controlled ultrasonic beam transducer (40, 41, 42) for projecting expanded unidirectional ultrasonic beams in a selected directions in a detection zone in the path of the swinging door and ultrasonic detector for converting reflected single multiple path ultrasonic beam energy into an analog electrical signal which constitute an acoustical image of objects in and bounding the selected detection zone. This acoustical image is stored or, a number characteristic thereof is stored and this acoustic image is then compared with a later acoustical image of an object in the selected detection zone and then the comparison is used to signal a lack of correlation between the first and second acoustical images to produce a signal preventing operation of the door opening.

Abstract: An apparatus capable of sensing sudden approach of a succeeding vehicle and emitting an alarm, while being free from malfunction that may otherwise be caused by the noise from the succeeding vehicle which has approached at a normal speed and stopped in the proximity.

Abstract: A plurality of ultrasonic transmitting elements and ultrasonic receiving elements are provided and are electrically switched in a sequential manner to change a region over which the existence of an object is to be detected, thus allowing the existence of an object to be detected over an extended range. The distance to the object and a particular region in which it is detected are displayed. The ultrasonic transmitting elements and the ultrasonic receiving elements are alternately disposed in a linear array. When switching the region over which the existence of an object is to be detected, the switching of the ultrasonic transmitting elements takes place in an alternate fashion with the switching of the ultrasonic receiving elements, thus changing the region at an interval corresponding to one pitch with which the elements are disposed in the array.

Abstract: An obstacle detection system has a sensor unit including a plurality of ultrasonic transducers and sequentially changes the number of pulses provided to groups of transducers, thereby performing front center sensing, front right sensing and front left sensing. The time between emission of ultrasonic waves and reception of waves reflected by an obstacle is calculated by a timer. A microcomputer computes the distance data and position data of the obstacle in accordance with obtained timer data and sensing region data.

Abstract: An ultrasonic transducer assembly incorporating an ultrasonic transducer and conically surfaced beam transformer wherein the conical surface of the beam transformer is mounted on the interior of closure means or end cap that seals the transducer (and any associated mechanisms) from the environment during non-operating periods and is moved into the prescribed position via rotational motion or a linear piston-like motion prior to operating periods. Suitable O-ring or gasket sealing means preserve the water tight integrity during non-operating periods and assures a seal during translational movements of the transducer assembly from operating to non-operating positions. On school buses, the beam transformer is translated to an operative position below the bus where, in conjunction with a microprocessor, it takes an accurate acoustic image before the bus door is opened and again before the bus resumes forward motion so as to detect whether students have crawled under the bus while it was stopped.

Abstract: A collision avoidance system for a two arm robot is direction sensitive. When the separation between the arms is sensed as equal to or smaller than a predetermined distance, the trailing arm is slowed to avoid a collision. The separation sensor generates a first "slow" signal when the separation is a first predetermined distance, a second "slow" signal when the separation is a second predetermined distance, smaller than the first, and a "stop" signal when the separation is a third predetermined distance, smaller than the second. The polarity of the drive signals for the arms determine their direction, and polarity sensitive comparators determine the direction of each arm. When the first "slow" signal is present and one arm is moving in the direction of the other arm, a speed reducing resistor is inserted in the circuit for the drive signal for the one arm to reduce its speed.

Abstract: This invention allows for the use of safety apparatus at the front and rear of the automobile, which serve as an addditional pair of "eyes" for the driver. The apparatus comprises a security system for the prevention of automobile collisions. The apparatus at the front of the automobile is connected to the front wheel system or to the steering mechanism by an appropriate rotary device which revolves so that the beams or waves do not encounter vehicles in oncoming lanes going in the opposite direction. The electronic safety apparatus emits beams or waves whose length is automatically regulated to correspond to weather conditions and to the speed of the vehicle so as to ensure safe braking distance.

Abstract: An ultrasonic transducer comprises a cylindrical housing embedded within a rear bumper of a vehicle and opening backward, a reflecting plate having a parabolic reflecting surface provided within the cylindrical housing along a closed end thereof and facing an open end thereof, and an ultrasonic vibrator provided in an upper wall of the housing at the focus of the reflecting plate for emitting and receiving ultrasonic waves. The ultrasonic transducer transmits ultrasonic waves behind the vehicle and receives ultrasonic waves reflected from an obstacle. The ultrasonic transducer further comprises a projecting member provided on the inner wall of the housing along the open end thereof for dispersing and cancelling the ultrasonic waves entering the housing at angles with respect to the axis of the housing. The projecting member has a smoothly curving cross section having a radius of substantially one fourth to five times the wavelength of the ultrasonic waves emitted by the ultrasonic vibrator.

Abstract: An obstacle sensing area ahead of a mobile robot is divided into a plurality of sensing regions. A number of ultrasonic transmitters and plural receivers on the robot cooperate to detect the presence of obstacles in the sensing regions. Coordinates representing four corners of each sensing region, and time data representing a time period from emission of ultrasonic waves from selected transmitters to reception of the waves by each receiver when the waves are reflected by an obstacle at each corner point, are prestored in data ROMs. The data ROMs are retrieved by a CPU in response to obtained time data, and precise position data of the obstacle in the sensing area is determined.

Abstract: An inter-vehicle distance control system for a vehicle wherein the distance between the vehicle and a preceding object and a relative velocity therebetween are detected by a detection system such as a radar system, and when this distance has become shorter than a predetermined value, a reaction force is imparted to a throttling operation member such as a throttling pedal. The vehicle operator is effectively advised of this fact.

Abstract: A method for detecting obstacles, such as people for example, in the operation of remote-controlled vehicles (10). The vehicle may be an industrial materials-handling truck or an industrial robot equipped with a data processing control system and transmitters (20,22) and receivers (24) for ultra-sound waves. Ultra-sound pulses are transmitted continuously in groups from the transmitter in a pre-determined pattern, and only one input signal having a pulse pattern corresponding to the aforementioned predetermined pattern for respective pulse groups is received by the receiver (24) and evaluated by the data processor for controlling maneuvering of the vehicle (10).

Abstract: An apparatus for detecting obstructions behind a vehicle, employing ultrasonic waves is disclosed. The apparatus comprises an ultrasonic transmitting and receiving device disposed on the rear portion of the vehicle, an electric motor for rotating the transmitting and receiving device at a constant velocity, an angle sensor for detecting the rotating angle of the transmitting and receiving device and a sonar circuit for emitting ultrasonic waves through the transmitting and receiving device at predetermined rotating angles, receiving ultrasonic waves reflected from obstructions through the transmitting and receiving device at predetermined rotating angles and measuring the distance to the obstructions from the time taken from the transmission to the reception of the ultrasonic waves.

Abstract: A luggage door unlocking device for a vehicle, by which a luggage door of the vehicle can be unlocked without using an unlocking key, is disclosed. The device comprises a portable transmitter for generating an unlocking signal of ultrasonic wave, an ultrasonic wave receiver which is mounted on the vehicle and which receives an ultrasonic wave from the portable transmitter, a discriminating means for subjecting the signal received by the ultrasonic wave receiver to waveform shaping to obtain a high-frequency pulse train and detecting a high-frequency pulse train of a predetermined pattern to obtain the unlocking signal, and an unlocking mechanism for unlocking the luggage door of the vehicle upon receipt of the unlocking signal after discrimination by the discriminating means. The transmitter has a power supply switch which is enclosed in a case having a clip for attachment to the clothes of the person who carries the transmitter and which is closed upon attachment of the clip to the clothes.