JPS597278A - Detector of obstruction - Google Patents

Abstract

PURPOSE:To reduce period and to detect exactly an obstruction by operating plural ultrasonic wave receivers simultaneously with each other, operating successively the same time-dividedly when modulation arises in the acoustic wave and operating simultaneously the same when there is no influence of interference. CONSTITUTION:For example, an obstruction is assumed to exist only in 11 among detection regions 11-14 set by wave transmitter and receivers 21-24. A transmission signal, a control signal for transmission and reception, etc. are obtd. in a circuit 5 for generating control signal. The transmission signal of a transmission circuit 5 is inputted to the transmitter and receivers 21, 23, which emit simultaneously ultrasonic waves to the respective regions 11, 13. Since the obstruction exists only in the region 11 to be detected, the wave reflected from the region 11 is received and is inputted with an analog switch for reception to an amplifier by a control signal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an obstacle detection device.The obstacle detection device of the present invention is used, for example, to detect a moving obstacle when a car is reversing.

2. Description of the Related Art Conventionally, many devices have been proposed that display the relative position of an obstacle using a plurality of transducers as a method of detecting obstacles to prevent collisions with automobiles and the like.

Conventional obstacle detection devices that use ultrasonic waves have extremely high detection speeds compared to those that use other waves, so if you try to determine the relative position of an obstacle using multiple transducers, have to be activated sequentially over time, resulting in poor responsiveness.Specifically, when detecting obstacles behind a car when reversing the car, it is necessary to operate the
Since the speed of retraction is about 1.4 rn per second, it can be easily inferred that sequential operation due to time division would have poor responsiveness.

In view of the above-mentioned problems with the conventional type, an object of the present invention is to arrange a plurality of ultrasonic transducers adjacently or relatively nearby and to operate them simultaneously.
The transducer/receiver that converts the received 4Flu into a sound wave due to the 1"l phase relationship and generates 1 is divided in time and operates sequentially, and if there is no influence of interference due to such a phase relationship, they may operate simultaneously. Based on this idea, even when there are a large number of transducers, the detection and display cycle can be shortened, and the object is to perform efficient obstacle detection.

In the present invention, a transducer with a phase number is used to send out a wave for detecting a dX obstacle and receive a reflected wave from the obstacle. A transmission/reception control circuit that controls the transmission of reflected waves from obstacles, a reception signal identification circuit that receives and receives output signals of the transmission/reception control circuit based on reception of the reflected q and j waves, and There is provided an obstacle detection device characterized by comprising a display circuit that receives an output signal from a separate circuit.

An obstacle detection device according to an embodiment of the present invention is shown in FIG. 21, 22° 23.24 in the device shown in Figure 1
An ultrasonic transducer is placed at a predetermined interval in the rear of a car, and is an element that converts f1 buttock energy into city air energy, and an ultrasonic transducer that cures the antenna that gives the radiation a certain directivity.
N, 12, 13, and 14 ID detection areas of the respective transducers, 5-digit control IHA signal generation circuit, 4-digit transmitting circuit, 3 (company) transmission/reception control circuit, 6 is the receiving circuit, and 7 is the display circuit. .

The details of the transmission/reception control circuit 3 in the first device are shown in FIG. In the circuit shown in Figure 2, 321
．． 322, 323, 324 are transmitting analog switches whose center control terminal conducts when it is "1" and opens when "0"; 325, 326, 327, and 321j are transmitting analog switches that operate in the same way as the transmitting analog switches. It is an analog switch. Further, 301, 302, 303, 304 are connected to transducers 21, 22, 23, and 24, respectively. 3
10, 3] 1 is connected to the receiving circuit 6, 1, 1
306, 307, 308, and 309 are signals for controlling transmission and reception, and are connected to the control signal generation circuit 5.

1 of the control signal generation circuit 5 in the apparatus shown in FIG.

Details of the wiring are shown in Figure 3. In the circuit shown in Figure 3, 521 is a CR oscillation circuit (unstable multivibrator)
, 522nd reset terminal is grounded, binary
Counter, 523 1d first monostable multivibrator, 524 second cliff stable multivibrator, 5251
1-l invert gate element, 526tJ: E
, OR (exclusive OR) gate element, 527°528.
529, 530, 531, 532, 533u and gate Yasuko. Terminal 501 is connected to transmitter circuit 4 .

Terminals 502, 503, 504, and 505 are connected to the transmission/reception control circuit 3. Terminals 506p507 are connected to the receiving circuit 6
connected to. Terminal 508, 509, 5]0°5]1
．． 5] 2,513 is connected to the display circuit 7.

Details of the electrical connection of the receiving circuit 6 in the apparatus shown in FIG. 1 are shown in FIG. In the circuit shown in Figure 4, 6'34°6351
l-1 amplifier circuit, 636, 637 are band pass filter circuits, 638.63M#! wave circuit, 640, 6tl are comparison circuits, 642, 643 are RSS flip flow rough 644
．． It is a 645d AND gate element. Terminal 601゜60
2 is connected to the transmission/reception control circuit 3. Terminal 605.60
6171 display circuit 7. Terminal 603゜604
is connected to the control signal generation circuit 5.

The details of the display circuit 7 and the air connection in the device shown in Figure 1 are shown in Figure 5.
In the circuit shown in the figure, 7a+'
1 b 17 c t 7 d each detection area 13 +
In the independent display section sA that displays the contents of 12, +3°14, only the details of 51 will be described since they have the same configuration. , 755°756.757,758,759,7
60 is an AND gate element, 761, 762, 763 are EX, OR gate elements, 764, 765, 766 are RS flip-flops, 767° 768, 769 are NPN transistors whose emitters are grounded, 770, 771
, 772 are lamps.

The terminals 702, 703, 704, 705, and 706 are all connected to the transmission/reception control circuit 5. Terminal 707:
I will be followed by Matsuzuki. Independent display circuits 7b, 7C, and 7d (input terminals are partially shown in the diagram).
41 '71 + , , =z Figure 76 shows the display D
The front view of the SP is installed on the rear package tray inside the vehicle. The display DSP in FIG. 6 is driven by the display circuit 7. In the display device DSP of FIG. 6, L, RF!
Storm the left and right sides toward the rear of the vehicle, 1.5. J
, 0.5 is the distance between the ultrasonic transducer and the obstacle) g
Hail value. 11 to the right when facing the rear of the vehicle (1111
When the area is set to , the 5th lamp of @l marked R
In the figure, it becomes 770,771,772.

An example of the graphical operations shown in FIG. 7 is shown in the time chart of FIG.

The operation of the FIG. 1 device is distributed below. Now, it is assumed that an obstacle exists only in 11 of the detection areas II, 12, 13, and 14 set by the respective transmitting/receiving wave WHs 21, 22, 23, and 24. In the control signal generation circuit 5, the clock pulse generated by the unstable multipipe rake 521 is divided by the binary counter 522 (iX), and the signal is input to the first intermediate stable multivibrator 523. Depending on the gate logic configuration of the signals transmitted, transmission signal 5 (501), transmission/reception control signal S (502), S
(503), S (504).

5 (505), receiving circuit control signal 5 (523), 5 (5
22, Q10), display circuit control signal-Ii3S (523)
.

Obtain S (532) and S (533). By connecting the output of the binary counter 522 to the second monostable multi-bi break 524, the distance connected to the display circuit 7 (discrimination signals 5 (524, Q), 5 (524°Q')
, 5 (5241Q") is obtained.

First, the control signal 5 (528) of the transmitting 4M analog switch 321, 323 is not "1", the input/output is short, and B1 of the transmitting signal 5 (527) of the transmitting circuit 5 is set to the transducer. 21.23 K input, each detection area 31
, 13, emits ultrasonic waves when opened.

Now, since there is an obstacle only at 11, the Sj reflected wave E1 is received at 30I, and E1 is input to the amplifier 634 via the receiving analog switch 325 according to the control signal S (530).

Since there is no obstacle in the detection area 13 set by the transducer 23, the reflected wave is not waited for and no signal is input to the amplifier 635 to which the receiving analog switch 327 is connected. In the amplifier 634, the amplified t or El is
stomach! 7 (7) via the 1-pass filter circuit 636
E I' is detected by the detection circuit 638, and the predetermined ratio iI! shown in FIG. 7(8)K is detected by the comparison circuit 640. <11(
The r+s flip-flop 6 is compared with the pressure level TH.
112. .

At the time of transmission, the RS flip-flop 642, which is set in advance by the receiving circuit control signal 5 (523), is reset at the rising edge of the output 5 (640) of the comparator circuit 640, and its output is set by the receiving circuit control signal 5 (522, Q12) is inputted to one side of the AND gate element 644, and the rectangular wave S (644a) is received from the transmission start t1 in Figure (12) of vJ7 (*t2t). On the other hand, the amplifier 635
It (:) is not input, so the RS flip-flop 643 is not reset, but the rectangular wave 5 (522, Q12) input from the terminal 604 and the AND gate element 645 are used to remove the logic Wl! Rectangular wave 5 (645a) from start t3 to reception (Fi possible time end t4t)
).

Next, after the receiving time of the transducer 21.23 ends and a predetermined time elapses, that is, after a time TI from the fall of S (528) in FIG. 7(2), the transmission ablog switch 9322.
324 control signal 5 (529) rises,
Ultrasonic waves are emitted from the transducers 22 and 24 into the detection area 12°14. Control signal 5 (531)
The reception analog switch 326, 3 operated by
28 to terminals 603 and 602 of the ossification circuit 6. However, in this case, there are no obstacles, so it is 5 (665a
) with the same length as 5 (6446).

5 (6456) is obtained.

Now, the distance signal 5 (644) obtained by the reflected wave from the obstacle in the detection area 11 is input to the terminal 701 of the display circuit 7, and the display circuit control signal 5 (532) I8 (53
Of 3), by taking the logical OR with the rectangular wave of S (532), it is inputted only to the independent display circuit 7a that displays 11 via the AND gate element 756. Independent display circuit 7allj: 3-stage distance discrimination signal 8 (524, Q)
, 5 (524,Q') , S (524,Q")
and reset) (N No. 5 (523) is input, and by taking the logical sum with the display circuit control signal 5 (532), it is output from the CAND gate elements 755, 758, 759, and 760, and distance discrimination is permitted. AND gate element 75
The distance signal output from 6 is also shown in Fig. 7 (18) (19).
11S (76]) I8 (7
RS flip-flop 764, which is reset in advance by the square wave 1 display circuit signal 62) (523),
Set 765 and set 8 at t in Figure 7 (23) and (24).
(764), 5 (765), the output becomes Q+J level. During this time, 5 (763) is il[J, so the R, S flip-flop 766 is not set to 1, and the output Q is reset as 5 (766).
” to hold. The output S of the RS flip-flop (764
), S (765), and 5 (766) are each NP
When connected to the base terminals of N-type transistors 767, 768, and 769, the lamp 770 is driven.
Point 771.772. In this set, 767.768 of the NPN transistors are driven.d)
, 770, and 771 are the only ones that appear.

If an obstacle lies within the detection area, the distance li! is determined as shown in FIG. Since the 11' signal (for example, 5 (644)) falls after A', no square wave is output from the exclusive OR gate in the display circuit 7, and the RS flip-flop -
Retains the "0" state when reset [7 lamps do not ignite. That is, to explain using the lamp lighting d1 second independent indicator circuit 7a, the distance signal is A (also N: A').
If it falls after that, the lamp will not light up, and B (or B/) and A
(or A') (7), only 770 lights up, and C
(or 770 when it falls between 0 and B (or B'),
When 771 lights up and falls in front of C (or c/ ), 77
0,771,772 lights up. Independent display circuits 7b, 7
c, 7d also display circuit control signals 5 (532), 5 (533)
), the contents of 12, 13 and 14, respectively, are displayed in the same way as the operation of 7a.

In this way, the contents of the detection area 11=I2*13p14 can be displayed as an independent signal.

In carrying out the present invention, the scale may be modified in addition to the embodiments described above. For example, in the obstacle detection device shown in FIG.
If 1 and 22 and 23 and 24 are arranged so that there is no interference, and 22 and 23 are arranged so that the interference is corrected, the order of activation is 21° and 22 at the same time, then 23 and 24 at the same time. It can be done.

Additionally, even in any case where the number of sonic wave transducers is three or more, the fzM order operation can be performed so that there is no influence of interference.

Further, as the wave, not only ultrasonic waves but also light, electromagnetic waves, etc. can be used.

According to the present invention, even when a large number of transducers are used, the detection and display frequency can be shortened, and obstacles can be detected accurately.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an obstacle detection device as an embodiment of the present invention, Fig. 21\Id1 is a diagram showing the configuration of a transmission/reception control circuit in the device shown in Fig. FIG. 4 is a diagram showing the configuration of the signal generating circuit, FIG. 4 is a diagram showing the configuration of the receiving circuit in the device shown in FIG. 1, FIG. 5 is a diagram showing the configuration of the display circuit in the device shown in FIG. 1, and FIG. 6 is a display FIG. 7 is a waveform diagram showing the waveform of each part of the device shown in FIG. 1. (Explanation of ladle numbers) II, 12, 13.14... detection area, 21.22,
23, 24... Ultrasonic transducer, 3... Transmission/reception control circuit, 4... Transmission circuit, 5... Control signal generation circuit, 6... Receiving circuit, 7... Display circuit,
DSP...Display device. @ Applicant Co., Ltd. Japan Auto Parts Comprehensive Research nf4'! Patent Attorney Akimizu Akira Patent Attorney Kazuyuki Nishidate Patent Attorney Misao Matsushita Patent Attorney Akira Yamaguchi

Claims (1)

[Claims] 1. A plurality of transducers that transmit waves for detecting obstacles and receive reflected waves from the obstacles; some of the transducers are operated simultaneously to transmit and receive waves; a transmission/reception control circuit that controls the transmission of reflected waves from obstacles received by the device; a received signal identification circuit that receives an output coefficient of the transmission/reception control circuit based on reception of the reflected waves; and an output of the received signal identification circuit. An obstacle detection device characterized by comprising a display circuit that receives a signal. 2. How many transducers can be activated at the same time? An obstacle detection device according to the first aspect of the invention, which is selected so as to be free from the effects of acoustic mutual interference. 3. The obstacle detection device according to claim 1, wherein the identification circuit is provided with the same number of received signal processing circuits as the number of transducers operated simultaneously.