JPS5867542A - Device for searching around vehicle - Google Patents

Abstract

PURPOSE:To accurately detect the short distance to an obstacle through ultrasonic waves, by mounting a contact detector of prescribed length on a bumper or the like so that a predetermined length is indicated when the detector generates an output signal. CONSTITUTION:A signal of ultrasonic waves or the like from a transmitter 23 is reflected on an obstacle and detected by a receiver 24. A flip-flop 30 generates an output signal showing the time H from the reflection to the detection, so that a measuring unit 31 calculates the distance to the obstacle. The switch 13 of a contact detector provided on a bumper is located at the tip of the detector of prescribed length so that the switch puts a delaying circuit 42 in operation when the switch is brought into contact with the obstacle. As a result, a distance display unit indicates a predetermined length. A switch 16, which is turned on when the distance to the obstacle has become zero, acts not through the delaying circuit 42 so that the display unit indicates that the distance is zero.

Description

[Detailed description of the invention]

The present invention is a device that detects obstacles around a vehicle using ultrasonic waves, laser beams, microwaves, etc., displays the distance to the obstacle, and issues an alarm when the obstacle approaches within a set distance. This invention relates to a vehicle surroundings search eye device that can reliably detect distance when approaching just before contact. Conventionally, this type of vehicle surrounding search eye device transmits ultrasonic pulses, laser light, or microwaves at regular intervals toward a warning area behind the vehicle, and then detects reflected waves from obstacles behind the vehicle. Detects the distance to the obstacle based on the time from transmission until the reflected wave is received, displays the distance to the rear obstacle, and issues an alarm when the detection distance approaches the set distance. The system is designed to warn drivers by issuing warning signs. Therefore, even if an obstacle exists in a position that is difficult to see from the driver's seat when reversing the vehicle, the driver can clearly see that the obstacle is there, making it easier to perform driving operations when reversing the vehicle. By the way, when a vehicle is put into a garage by reversing, there are cases where the vehicle is reversed to the edge of a crossing or a fence, and the vehicle is stopped within a few centimeters of the obstacle. In such a case, when the above device approaches an obstacle, the unevenness of the reflection surface of the obstacle increases the fluctuation in the received level of the reflected wave, making it impossible to detect the correct distance. , the received signal of the reflected wave with a short propagation time is superimposed on the received signal of the direct loop from the transmitter to the receiver, and the received signal of the reflected wave is masked, making accurate distance detection impossible. There was a fear that it would disappear. The present invention has been made in view of the above, and is a device that detects and displays the distance to an obstacle around a vehicle using ultrasonic waves, light, or radio waves. Therefore, when the contact detection means protruding from a part of the vehicle body facing the warning area contacts an obstacle and outputs an output, the distance determined by the protrusion length of the contact detection means is displayed. Hereinafter, the present invention will be explained based on the drawings. FIG. 1 is a perspective view of a vehicle in which a rear bumper is provided with contact detection means according to the present invention. That is, a projecting portion 12 is provided at the center of the rear end of the rear bumper 11 of the vehicle 10, which deforms when it comes into contact with an obstacle and activates a contact detection means provided inside. FIG. 2 is a sectional view showing an embodiment of the contact detection means of the present invention provided on the overhanging portion 12 of the rear bumper 11 shown in FIG. First, to explain the structure, the projecting portion 12 has a shape as a retractable bellows made of an elastic material such as rubber, and is supported by a mounting plate 18 fixed inside the rear bumper 1 inside the projecting portion 12. and a contact member 1γ at the tip.
and 13A, the switch 13 is slidably supported by a spring 15 with a sliding shaft 14 fixed to a contact member 13h, and a switch 13 is supported by a spring 17 on a mounting plate 18 at the rear of the switch 13. The switch 13 is turned on when the contact members 1γ and 19 come into contact with each other due to the deformation when the tip of the overhanging member 12 comes into contact with a book. The switch is configured to turn on when the overhanging portion 12 is further pushed by an obstacle and the sliding shaft 14 is pushed into the switch by a predetermined amount in the state where the contact members lγ and 13h are in contact with each other, The distance @L when an obstacle comes into contact with the overhang part 12 is determined by the overhang length of the overhang part 12 with respect to the rear end surface of the rear pump 11, and the distance of the obstacle when the switch 16 is turned on is determined by the distance @L when the obstacle contacts the overhang part 12. Liano (distance of contact with the rear end surface of the amplifier 11, that is, L = 0
I am trying to keep it in the meter condition. FIG. 3 is a block diagram showing an embodiment of the present invention using the above contact detection means. First, to explain the configuration, (a) is a reference clock generator that transmits a clock pulse of a predetermined frequency, and 4 is a timing signal that outputs a command to transmit an ultrasonic pulse at every fixed period Tp based on the reference clock pulse. The transmission timing control circuit η is an ultrasonic oscillation circuit that causes the ultrasonic transmitter Z to emit ultrasonic pulses toward a predetermined warning area based on a timing signal. On the other hand, as a circuit unit that receives and processes the ultrasonic pulse reflected by an obstacle, Sae is an ultrasonic receiver that receives the reflected wave of the ultrasonic pulse, and δ is a receiver that amplifies and outputs the received signal of the ultrasonic receiver 24. The amplifier is a filter circuit that removes noise contained in the received signal and extracts the reflected ultrasonic pulse signal.
is a waveform shaping circuit that shapes the received signal from the filter circuit 26 into a rectangular wave signal, 4 is an OR gate, and 蜀 is set by the rising edge of the timing signal from the transmission timing control circuit 21, and is reflected by an obstacle via the OR gate A. This is a flip-flop that is set when the received ultrasonic pulse signal rises to H level. Further, 4 is a delay circuit that delays the timing signal from the transmission timing control circuit 21 by a predetermined time and resets the free lag flop via the OR gate 28, and the delay time set in this delay circuit 4 is a predetermined time within the transmission period Tp of the ultrasonic pulse, and when the time from when the ultrasonic pulse is transmitted to when the ultrasonic pulse reflected by an obstacle is received exceeds the delay time, the delay circuit This output forces the flip-flop (to) to be reset,
This reset action determines the maximum detection distance for obstacles. 31 is a measurement unit that measures the distance to an obstacle according to the propagation time of the ultrasonic pulse for which the flip-flop (9) is producing an H-level output; A counter 32 that counts clock pulses from a clock oscillator, and a counter 3.
It has a latch circuit that latches the count value of 2 and holds and outputs it during the next measurement cycle. The sensor is a display section that displays the measured distance to the obstacle given by the latch circuit, and has a display section that numerically displays the measured distance from the driver that produces the display signal using a dot matrix display. Furthermore, the alarm unit outputs an alarm when the measured distance is within a predetermined distance, and the digital comparator blade outputs when the measured distance is less than the set distance set by the setting device 39, and the digital comparator 38 outputs a buzzer. 41
It has an alarm circuit 40 that sounds. On the other hand, as means for detecting the distance to an obstacle according to the operation of the switches 13 and 16 constituting the contact position detecting means shown in FIG. A delay circuit 42 is provided, which delays the timing signal from the circuit by a predetermined period of time and outputs the delayed timing signal.
The output of this delay circuit 42 is configured to reset a flip-flop via an OR gate. The delay time set in the delay circuit 42 is determined as the time required for the ultrasonic pulse to propagate through the extended length L of the extended portion 12 shown in FIG. The switch 16, which is turned on when the distance to the obstacle becomes zero, is connected to reset the flip-flop by applying a timing signal from the transmission timing control circuit 21 directly to the flip-flop via the OR gate. There is. Further, between the % filter circuit and each waveform shaping circuit, there is a relay contact which is turned off when the switch 13 is turned on. Next, the operation of the present invention shown in FIG. 3 will be explained with reference to time charts showing signal waveforms of various parts shown in FIGS. 4 and 5. However, until an obstacle comes into contact with the overhang 12 provided on the bumper, as shown in the time chart HC in FIG. Ultrasonic pulses are emitted toward the warning area for each periodic valve, and the ultrasonic pulses reflected by obstacles enter the ultrasonic transmitter after a predetermined time, are amplified by the receiving amplifier δ, and then filtered. The noise component is removed by the circuit 5, the waveform is shaped into a rectangular wave signal by the waveform shaping circuit n, and the flip-flop (9) is reset via the OR gate group. The flip-flop (I) is set by the timing signal at the time of transmitting the ultrasonic pulse before the reception signal is obtained, and generates an H level output. The time it takes for the object to be reflected by an obstacle and received
This will produce a level output. The H level output of the flip-flop I is given to the counter 32 of the measuring section 31, and the counter 32 indicates that the flip-flop (9) is H level.
The clock pulses from the reference clock oscillation 4 are counted over the time period during which the level output is generated, and the latch circuit: (3
is retained and output. The count value of the clock pulses counted by this counter 32 represents the propagation time of the ultrasonic pulse, that is, the distance to the obstacle, and the latch circuit Okara outputs measurement data representing the distance to the obstacle. Ru. Measurement data from the measuring section 31 is converted into a display signal by the display section connected to the driver, and the distance to the obstacle is displayed numerically between the displays. Furthermore, the measured distance of the measuring section 31 is also input to the digital comparator of the alarm section 37.
When the measured distance exceeds the distance set by the setting device 39, no output is made, but when the measured distance falls within the set distance, the digital comparator outputs an output, activates the circuit 40, and sounds the buzzer 41 to stop the I4 harmful object. informs the driver that the distance is within the set distance. Next, suppose that the distance to the obstacle becomes closer, the obstacle contacts the overhang 12 shown in FIG. 2, the contact member 13α contacts the contact member 1υ, and the switch 13 is turned on at time 1. First, turn off the switch to stop ultrasonic reception, and after the time has passed.

[First, the transmission timing control circuit 21
The timing signal output from the gate is input to the delay circuit 42 via the switch 13, and after a predetermined delay time corresponding to the overhang distance LK, the delay circuit inputs the timing signal to the OR gate 3.
The signal is output to the flip-flop blade via the timing signal, and the flip-flop I, which has been set in advance, is reset by the timing signal. Therefore, the time for the flip-flop to produce an H level output coincides with the delay time "tJ" of the delay circuit 42, and the counter blade of the measuring section 31 changes from the reference four-channel oscillator addition over the delay time "tJ". Count the clock pulses of
This count value corresponds to the overhang length L of the overhang part 12, so that the display part 4 shows that the overhang part 1
The predetermined distance corresponding to the overhang length L of 2 is now displayed. Furthermore, if the vehicle continues to move backwards and the distance to the obstacle becomes closer, the overhang 12 shown in FIG. The switch 16 is turned on at the time when the obstacle comes into contact with the spring 11. When the switch 16 is turned on in this way, after the time The first timing signal from the transmission timing control circuit 21 is applied to the flip-flop through the switch 16 and the OR gate array, and the flip-flop remains reset, so the counter blade The count value becomes zero, and the display on the display device will display that the distance to the obstacle is zero meters.In the embodiment shown in FIG. Even when an obstacle approaches the actuation position and the distance is displayed as zero, the switch 16 is supported by the mounting plate 18 by the spring 17 and pushed into the interior of the rear panel 11. The vehicle can be moved backward until it makes complete contact with the obstacle.Also, although the above embodiment uses ultrasonic waves to detect the distance to an obstacle, it is possible to use laser light or microwave The same is true when using the following.As explained above, according to the present invention,
In a device that detects and displays the distance to an obstacle around a vehicle using ultrasonic waves, laser light, or microwaves, a contact detection means is provided protruding from a part of the vehicle body facing the warning area,
When this contact detection means contacts an obstacle and outputs an output,
Since the predetermined distance determined by the protruding length of the contact detection means is displayed, even if the distance to the obstacle can no longer be accurately detected by ultrasonic waves, light, or radio waves, there will be no mechanical contact with the obstacle. It is possible to accurately detect and display the approaching distance to an obstacle by contact, so when entering a garage etc., while looking at the distance display to the obstacle,
The effect is that the vehicle can be backed up to the very edge of the obstacle. Further, by providing a plurality of switch means for detecting contact with an obstacle, and sequentially turning on the switches according to the amount of contraction of the overhang, the distance to the obstacle is sequentially displayed according to the operation of each switch. Furthermore, the vehicle's reverse driving operation becomes more accurate. Furthermore, in the present invention, the distance measurement means based on the propagation time of ultrasonic pulses or the like is directly used to display the distance by the contact detection means. This can be realized with a simple circuit configuration in which a delay circuit with a delay time set according to the time that the ultrasonic wave propagates over the overhang distance is added to the circuit.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a vehicle in which the contact detection means of the present invention is provided in the rear bumper, FIG. 2 is an explanatory diagram showing one embodiment of the contact detection means used in the present invention, and FIG. 3 is an embodiment of the present invention. A block diagram showing an example, and FIGS. 4 and 5 are time charts showing signal waveforms of various parts in the embodiment of FIG. 3. 10... Vehicle 11.11e Rear bumper 12.
Building/overhang part 13, 16... switch 13g,
13A --@ Contact member 14 --- Sliding shaft 15 , 1
7...Spring 18-...In front of the mounting plate...Reference clock oscillator 21...Outgoing timing crawler circuit ρ...
Ultrasonic oscillation circuit β・Ultrasonic transmitter...Ultrasonic receiver 5...Reception amplifier...Filter circuit I...Waveform shaping circuit...Fist or game)
4, 42...Flip delay circuit (capital)...Flip 70
(1...Measuring section (...Counter)
...Latch circuit A...Display section Connection...Driver I...Display device 37...Alarm section side...Digital comparator 391st setter 40...Alarm circuit 41,...
·buzzer

Claims (2)

[Claims] (1) A device that detects and displays the distance to obstacles around the vehicle using ultrasonic waves, light, or radio waves, is installed protruding from a part of the vehicle body facing the warning area, and is activated when it comes into contact with an obstacle. and distance output means that outputs a distance determined by the protrusion length of the contact detection means as the distance to the obstacle when the contact detection means outputs the distance. Peripheral search eye device. (2) The vehicle surroundings search eye device according to claim 1, wherein the contact detection means comprises a plurality of switch means that are sequentially turned on in accordance with the amount of contraction of the protrusion due to contact with an obstacle.