Abstract: An ultrasonic detection circuit for detecting obstacles behind a backing motor vehicle, and an ultrasonic communication circuit are automatically switched such that the ultrasonic detection circuit is operable only when the communication circuit is not in use. Furthermore, the ultrasonic detection circuit may be operated only when the motor vehicle is in one or more particular operating conditions. The system comprises a rear ultrasonic transducer used for both the detection circuit and for the communication circuit so that detection of obstacles behind the vehicle and communication with another motor vehicle behind the vehicle are possible, and a front ultrasonic transducer used for only the communication circuit so that communication with another motor vehicle ahead of the vehicle is also possible.

Abstract: Obstacles in the path of a vehicle are detected by an ultrasonic radar system which measures the time between the instance of transmission of an ultrasonic wave pulse and another instance of reception of an echo signal. The transmitting period is controlled to be retarded from a reference or standard transmitting period by a time length including the measured time at every other transmitting period. The measured time is compared with a reference time to check whether a detected obstacle is within a dangerous range. This comparison is effected at every other transmitting period so that a false detection signal caused from a far obstacles is prevented from being produced. As a result of the comparison an alarming device is energized to alert the vehicle driver when necessary.

Abstract: A moving obstacle detection system using a Doppler radar device for an automotive vehicle which detects and informs a vehicle driver that another vehicle (moving obstacle) approaches or moves away from the detecting vehicle, wherein there is provided a means for determining whether the rate of change of the period of a Doppler signal outputted from the Doppler radar equipment with respect to time exceeds a predetermined value so that an erroneous alarm in response to a pedestrian or another vehicle traversing the front detection area of the vehicle, e.g., when vehicle is at rest at in an intersection is inhibited. Consequently, more reliable detection of approach or departure of another vehicle can be achieved.

Abstract: A moving obstacle detection system for an automotive vehicle utilizing a doppler effect of the transmitted wave against an obstacle which runs in front of the vehicle such as another vehicle.

Abstract: A rearward obstruction sensing system for an automotive vehicle detects obstructions within plural warning areas defined near the vehicle body. Four speakers near the four corners of the passenger compartment face toward the allocated warning areas when seen from the driver. When an obstruction is detected within a warning area, the speaker disposed on the side of the warning area within which the detected obstruction exists produces an intermittent alarm sound. Therefore, the driver can intuitively or sensorially recognize the direction of an obstruction existing within dead angles from the driver without watching a zone display device while backing up his vehicle. Further, the driver can determine the obstruction distance by distinguishing the period of the intermittent alarm sound, because the period thereof is proportional to the obstruction distance.

Abstract: An obstacle monitoring device for the rear of a vehicle comprising a plurality of ultrasonic obstacle detectors which are operated sequentially at a predetermined time interval, and an electronic monitor for supplying the obstacle detectors with their operational timing sequences at the predetermined time intervals and for determining distance information for each detector based on the changing pulse width of electric currents for each of the obstacle detectors within a particular time interval, which pulse widths correspond to the distance between an obstacle and the rear of the vehicle. A single transmission line connects the obstacle detectors with the monitor so that the number of wires in a wire-harness is reduced between the obstacle detectors (outside the vehicle) and the monitor (inside the vehicle).

Abstract: A circuit for measuring and indicating the separation distance between a vehicle and adjacent obstacles, consisting of a pulse controlled ultrasonic generator, an ultrasonic transmit-receive transducer connected to the generator for transmitting direct ultrasonic pulse signals to distant obstacles, and receiving these signals that are reflected from the obstacles, an amplifier and detector circuit connected to the transducer output for amplifying the received pulse signals, a first comparator which is connected to the amplifier and and detector stage, and a start-stop counter coupled to the output of the first comparator for measuring the difference in time between the end of the transmitted ultrasonic signal, and the reception of the reflected signal from the obstacle. There is also provided a noise suppression circuit coupled to the output of said first comparator and a second comparator coupled to both the output of the noise suppression circuit and the output of said start-stop counter.

Abstract: An intervehicle distance control system for a vehicle which, when there exists a possibility of collision between the vehicle and an interfering object ahead thereof, generates a control signal and imparts to a vehicle accelerator member an operation reaction force corresponding to the control signal. The driver is thereby alerted as to a possibility of collision, while the selection of acceleration operation is substantially entrusted to the driver. In the absence of such control signal, the reaction force has a strength of substantially zero. Regardless of the vehicle speed, the driver will never suffer from a metal burden due to operation of the control system.

Abstract: An ultrasonic detector for roadway vehicles comprises an array of electroacoustic transducers mounted on the rear of the vehicle. The transducers are sequentially driven by a transmitter circuit to transmit a pulsed, laterally shifting ultrasonic energy toward an object located behind the vehicle in one of plural regions defined by partially overlapped directivity patterns of adjacent transducers. A receiver circuit is coupled to the transducer array to receive echos returning from the object during the interval between successive beam transmissions. A logic circuit detects the lateral position of and the distance to the object for giving relevant indications on a display unit, the audible tone being variable depending on object distance. An audible warning device is optional.

Abstract: The equipment for maintaining the spacing of track-bound vehicles (1) shall prevent collisions of the vehicles (1). For this, light emitters radiating rearwardly and laterally in desired directions are provided at the rear on the vehicles (1) and light receivers receiving from in front and from the sides in desired directions are provided at the front on the vehicles (1). A drive control reduces the speed of a vehicle (1) with increasing received light intensity, i.e. with decreasing spacing from the vehicle (1) travelling immediately ahead. The equipment is usable for floor conveying plants with vehicles (1) travelling at small spacings one behind the other. An embodiment of the equipment is suitable for vehicles (1) travelling forwardly and rearwardly. A further embodiment of the equipment is suitable for vehicles (1) on neighboring travel paths. Special measures are provided for compensation of the influences of ambient light.

Abstract: An automotive rear safety checking apparatus which comprises a plurality of obstacle detectors mounted on the rear part of the automobile for radiating ultrasonic wave on the watching areas smaller in width than the width of the automobile respectively and detecting the ultrasonic wave reflected from an obstacle. The ultrasonic wave is radiated from the obstacle detectors in time division. Pulse signals in the number associated with the distance between the obstacle detector and the obstacle are generated in response to the detection of the ultrasonic wave reflected from the obstacle, so that the relative positions of the automobile and the obstacle, are indicated two-dimensionally in accordance with the pulse signal.

Abstract: A diaphragm-type transducer assembly is mounted on the rear of an automobile to transmit ultrasound into left- and right-hand target regions near the automobile. Spoilers are mounted adjacent to the transducer diaphragms to disrupt the air flow around them and prevent negative pressure that could adversely affect the operation of the transducer. The circuitry for driving the transducers includes relays in the signal-lamp circuit to detect when the turn signal is turned on, and it only transmits ultrasound pulses in response to signal-lamp actuation. The system initially "listens" for objects outside the target region in order to test the circuitry, but it subsequently responds only to objects within the target region.

Abstract: An ultrasonic wave transmitter and receiver adapted to be mounted on the rear portion of a vehicle to detect the distance between the rear end of the vehicle and any obstruction located at the rear side of the vehicle. The ultrasonic wave transmitter and receiver includes an ultrasonic transducer attached to a lower part of the vehicle at a portion spaced from the rear end of the vehicle in the forward direction of the vehicle by a predetermined distance, a horn opening rearwardly from the vehicle and a wave guide tube through which the horn and the ultrasonic transducer are coupled to each other. The distance between the ultrasonic transducer and the rear end of the vehicle is selected to correspond to a time length which is long enough to sufficiently attenuate the residual oscillation of the ultrasonic transducer.

Abstract: A rear obstacle detecting system for automotive vehicles includes an ultrasonic transmitter/receiver unit, distance detecting unit and an indicator for measuring distance to an obstacle while a vehicle is in backward movement. The ultrasonic transmitter/receiver unit having a ultrasonic vibrator is always energized as long as the vehicle is in an operating condition irrespective of whether the vehicle is in a backward movement or not, in order to maintain the ultrasonic vibrator being vibrated to achieve a self-cleaning function. The indicator is energized only when the vehicle is in backward movement.

Abstract: An ultrasonic ranging device for use in a vehicle having a high frequency oscillator supplying continuous sine wave signals to a power amplifier through a first gate controlled by a timer. A second gate controlled by the timer supplies an amplified sine wave signal from the power amplifier to a piezoelectric transducer mounted on an exterior portion of a vehicle. The transducer produces a series of repeated ultrasonic pulses and receives echoes from nearby objects converting the echoes into electrical return signals. A receiver amplifies the return signals and supplies them to a coincidence gate, which is enabled for relatively short time intervals by a timer. The coincidence gate supplies an output signal to an indicator when the return signal is detected during the interval that the gate is enabled.

Abstract: An automatic alarm is disclosed for detecting obstacles behind a vehicle as the vehicle travels backwards. The alarm includes a casing mounted at the rear of the vehicle and having a rearwardly facing opening. A revolving disc is mounted within the casing which is driven by a motor in the casing. A printed circuit plate is fixed within the casing under the revolving disc. A supersonic transmitting member is installed on the revolving disc. A supersonic receiving member is installed on the revolving disc. The transmitting and receiving members are simultaneously alignable with the opening and are electrically connected to a printed circuit on the printed circuit plate at least when the transmitting and receiving members are aligned with the opening, so that the transmitting member emits a signal which is deflected off adjacent obstacles and is detected by the receiving member.

Abstract: Apparatus for detecting the presence of an object moving relative to a vehicle within a location adjacent said vehicle, which location is hidden from the view of the operator of the vehicle; which comprises a first transducer mounted on the vehicle for transmitting sonic signals in a frequency range of about 30 to 40 Khz into the hidden location, a second transducer mounted on the vehicle in spaced relation to the first transducer for receiving a portion of the sonic signals reflected from an object present in the hidden location, a first high frequency (transmitter) audio amplifier powering the first transducer to cause the first transducer to transmit the sonic signals in the frequency range of 30 to 40 Khz, a second high frequency (receiver) audio amplifier for amplifying the signals received by the second transducer, a tuned amplifier for receiving a portion of the amplified signals from the receiver amplifier and being simultaneously coupled to the transmitter amplifier; the transmitting transducer, the

Abstract: A system for locating and determining the distance to an object with respect to a movable vehicle is provided which utilizes at least three transducers wherein at least two of the three transducers operates either as a receiver transducer, in which case the remaining transducer operates as a transmitter transducer, or two of the three transducers operate as transmitter transducers in which case the remaining transducer operates as a receiver transducer with the system also including means for sequentially operating the three transducers for sending and receiving reflected ultrasonic signals to simultaneously determine both the location and distance of persons or objects with respect to the transducers.

Abstract: A direction indicator giving a visual indication of the direction of origin of incident sounds having frequencies in a predetermined frequency range, is disclosed herein. The direction indicator embodies at least three sound detectors, each having an active filter passing electrical signals in a predetermined frequency range and a light emitting diode giving a visual indication of the intensity of the sound in the predetermined range received by the associated sound detector. Two of the sound detectors are disposed to preferentially receive sounds from opposite directions, and the third sound detector is disposed to receive sounds originating from a third direction normal to the directions of the first two. In the preferred embodiment, the direction indicator is an emergency vehicle direction indicator for use in an automobile giving the operator a visual indication of the direction of an emergency vehicle sounding its siren.