JPS60236078A - Device for detecting distance to obstacle - Google Patents

Abstract

PURPOSE:To recognize correctly and easily the distance to an obstacle by receiving the reflected wave of an ultrasonic waves signal transmitted and by displaying the distance to an obstacle found with counting of the number of reference pulses during from the transmission to the receiving. CONSTITUTION:An ultrasonic wave with the prescribed width is generated at an ultrasonic wave signal generating part 52-54 according to the clock signal generated at a clock pulse generating circuit 51 and is transmitted for an obstacle from a wave transmitting part 23. The reflected wave from the obstacle is received at a wave receiving part 24 and a pulse PE is obtd. by rectifying the wave form at an amplifying and detecting parts 55-61. On the other band the clock signal of a clock pulse generating circuit 51 is inputted to a distance pulse generating part 64 and a standard distance pulse RP with the time width corresponding to the time reciprocating the prescribed distance of a sound-wave is obtd. While, then, the receiving pulse PE is obtd. from the ultrasonic transmission, the number of the reference distance pulses RP is counted and converted into a distance and displayed on a displaying part 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an obstacle distance detection device, and more particularly to an obstacle distance detection device suitable for use in detecting the distance to a real harmful object behind a motor vehicle.

[Prior art and its problems] When driving an automatic 11, the distance between the rear of the middle 14 and an obstacle when reversing #recognize the distance #1'' Use your nerves and turn the 1 into one handle...
g) Su, ``I was looking at it carefully, but then I made a mistake ζ゛)1
)・There are many stories like this. Many of these +11 reasons 1
．． It's only one small damage, but II! F1. De big G/& and t
4t, including 11 dangers, and it is necessary to eliminate all 1G accidents.
There are 2. 1. b・12, conventionally this type of +f(//Il
”, r l11i! is immature: -1; at l (l 1
J311, -1i has been defeated by J311, -1i Pass to 11 people C11 easy and expensive Tel/Pino T Mela is 11 in 1
1) Recognizing the rear through pHrIi has been done for some time, but there is no effective solution.
It wasn't.

[Objective of the Invention 1 The present invention provides: 1. In view of the above-mentioned problems, for example, even a person with unskilled skills can easily do +I',,+ and after the first car;11. [Uh, IJI is a device that can accurately and easily recognize the distance to obstacles! The purpose is to provide

[Structure of the Invention] That is, the present invention includes a clock signal generation section and a clock signal generator.
The ultrasonic wave signal generating section j′1 generates a JII sound wave signal of a predetermined width according to the reference number, and the ultrasonic wave signal generator j′1
A transmitter that sends out waves and the Jll that is reflected by an obstacle.
A receiver that receives rf waves and an output of the receiver (l'l
an amplification/detection section that amplifies and detects the ultrasonic waves; The number of the reference pulses is increased to 11 until it is received. 11
It is characterized by comprising a number of parts and a display part that digitally increases or decreases the 31 numerical values of the man-hour parts.

[Example 1 The details of the present invention will be explained below with reference to the illustrated embodiments.

In Figures 1 to 4, ■ is the main body of the device, and the distance is 2.9! An alarm speaker 3, a power switch, an alarm distance adjustment knob 4, a plug 5 for connecting to the cigarette lighter socket 1, an Ichihara cable 6 connecting the plug 5 and the main body 1, an operation mode cut-off switch 7 and 41. 1]
The 11th metal fitting 8 is full, and the 11th metal fitting 8 is bullet P.
The rear end of the sun visor I is fixed to the surface 1 of the main body 1, and the sun visor I
I'm shaking 1 to make it look like +, and this is 31:r.
The main body part 1 is fixed to a reconnaissance aircraft ~11.

Reference numeral 21 is a wave transmitting/receiving controller, and the bumper 311. etc. Automatic middle tD section 1 removal・
I get kicked by 1. Transmission/reception wave Cola L 211.1 iX Limbs 2
3 and the receiver 24 are supported on the bracket I/22 in such a way that the opening 11 of the 4I-L and E 2 faces the vehicle pulling force. 4 [ is control cable e, connector 42 in the middle part right 17, sending/receiving 11I/co:-/
At t.21, the reversing light 43, tail light 44, and main body fiR1 were turned off.

Figure 5 shows the 1tc air circuit of wooden z1. In Figure 1, 51 is a clock pulse generator circuit, and the interval is 200.
m5. Pulse width + 00 m s paste■]Tsuku pulse C
Generate P. 52 is Nakayasu 1' Maru J-Pi/Later-
Then, the driving pulse Dr of 0.2 ms is generated by setting the above-mentioned dot-pick pulse CP 1'tl-1y <riIYIS', .HJ. Reference numeral 53 denotes an oscillation circuit which generates 4.0 K I (high frequency 4+'r in the ultrasonic range of z) 1 while the drive pulse DP is applied. 54 is an amplifier circuit which amplifies the above-mentioned 401 (Ilz high frequency signal t) and drives the above-mentioned transmitter 23.

5 is a narrowband amplifier circuit, with a 40 K 11 z parallel resonant circuit 56 as a load circuit, and q1 input to the receiver 24 described above.
-4- The various K 1m were sent out from the above-mentioned transmitter 23 and reflected by hitting an obstacle behind the automatic transmission.
Only the pulsed B sound wave of 0 K 11 z is amplified.

5711' and Jfl's amplifier circuit further amplify the output signal of the narrowband amplifier circuit 55. 58.59 further amplifies the output signal of the amplifier circuit 57 using the above-mentioned 1*(1) range amplifier circuit 55, parallel resonant circuit 56, rotary spool 1 circuit, and resonant circuit.

60 is a detection circuit, which outputs the output 1+ of the narrow band amplifier circuit 58;
The 40 KHz ultrasonic pulse signal r'i is detected. A waveform shaping circuit 61 shapes the detection output of the detection circuit 60 and generates a pulse PE. This pulse PE has a phase 1'1J of waves reflected by the obstacle. (i 2 is a cell I/reset flip/] l: J , . . . , the clock pulse CI' is °11 is jl
? -Reset.

Reference numeral 63 denotes a delay circuit which compensates for the delay in each of the circuits 52 to fi 21 by transmitting the I-7 pulse CP for a predetermined time, e.g.
4 is a reference distance pulse generation circuit, and the f1 speed is 340m1s.
Then, the 11th wave generates the reference distance pulse RP at a time interval of 0.588 m5, which is the time required for one return. 65 is an AND circuit, which combines the Q signal of the flip-flop 62 and the ), (take the AND of the quasi-distance pulse l(P).

A counting circuit 66 counts the number of reference distance pulses PR that have passed through the AND circuit 65. In addition, this ll number circuit 66 also has a clock pulse CPd that has passed through the delay circuit 63.
is supplied as a reset signal. 67 is a latch circuit, and the latch signal L; l, )'L1- is connected to 11! The number (lIi is latched. Note that these,
For the 1a circuit 66 and the latch circuit 67, those having a power supply reset function are used.

2 is the aforementioned distance display element, which is maintained by the latch circuit 67)11
．． Displays the number f of A1 in two digits. In this example, l
Since the distance between the obstacle and the wave transmitting/receiving unit 21 is displayed at the middle position, the 8-segment L E
The decimal point 2b of D 2 a shines to indicate that the upper digit corresponds to meters. Also, this distance display element f2 is supplied with an electric voltage gVT that is applied to the taillight 44. When turned on and this heavy pressure VT is supplied (that is, at night), the brightness of the distance display element f2 is reduced by a predetermined value. Various methods can be considered for reducing the brightness, but in this embodiment, the common terminal C of the distance display element 2 is
191 is grounded via a constant voltage Zener diode ZD, and when the voltage VT is not applied, that is, during the daytime, both ends of the Zener diode ZD are short-circuited to reduce the brightness of the display element 2 to 1- It's spreading.

69 is a delay circuit 'M, which outputs the delayed clock pulse CP.
d further delayed by 70 m S;; 1! 1. -6,:
) The latch circuit 67 receives the latch signal I11, and 1. supply.

70 is supplied via a semi-stable multiplier fno1/-ta r4 extension circuit 63; 'd~γ
In synchronization with the rise, a pulse PΔ is generated at 2'lJ? s, the pulse width of this pulse PA is 1111 alarm distance~adjustment"')
Ill change 1 town 11'L vessel v rotated by Mami 4
n and the time constant of the capacitor C>i−;j. 71
1.1 An]・In the circuit, this pulse PA and the above 1 * 04
Take the logical score with pulse 11A. 72 goes to the medium stable multi-function f break and responds to the output of the riir AND circuit 71, where>i,' II! For example, a pulse with a width of 3 seconds is generated between r and λ. 731. i, W +lJ signal oscillation circuit generates an 11 string wave of, for example, ] OOOII z, and supplies this to the above-mentioned alarm speaker 3.

74 is a constant voltage circuit, which is supplied via the power switch 75 belonging to the aforementioned plug 5.1 (r), the source cable 6 and the aforementioned 01 transformer V Rw II; 'IJ' vehicle pressure Vcc is generated by controlling the port.This ') 1! The voltage Vcc is the source of the right voltage. Note that the switching control terminal f-5 of this constant voltage circuit 74 is connected to the switching control terminal f-5 via the operation mode changeover switch 7.
&[When the voltage VR applied to the light 43 is supplied and the operation mode selector switch 7 is connected, it is turned on only when the reversing light 43 is turned on, that is, only when the car is reversing, and When this switch 7 is open, a constant voltage Vcc is generated whenever a switch 75 is turned on, and the device is operated.

The operation of the obstacle distance detection device of the present invention will be explained by adding a ptSB diagram. First, the knob 4 in FIG. 1 is turned from the OFF position to the desired alarm distance, thereby closing the power switch 75 and supplying the battery voltage VB to the constant voltage circuit 74. If the mode selection switch 7 is open at this time, as described above, just turning on the power switch 75 will generate the constant market pressure Vcc, and the decimal point 2b of the distance display element 2 in FIG. 1 will light up. to indicate that the device is working.

When constant voltage Vcc is supplied, JJ', il number circuit 66
and latch circuit 1i 71'', +iii, 1'
At 7? II and III are reset and their contents become zero. 5 Also, the clock pulse is generated) 1 circuit 51 generates 11 pulses CP command S'lJ as shown in Figure 4ii.

)'t', l: of this clock pulse CI' is 11,
'Response 1. (Medium stable multi-vibrator 1/-tar 52 is (1
, 7rn 4+ pulse Dr is generated, and the oscillators 53, l
11141I, l Muk 4 is driven, transmitter 23 or 64
(I K II 7.0.2Ii IS width ultrasonic pulse is passed after automatic Φ] 11.' towards hk ()l).

At this time, if the pulling force of the wave transmitting/receiving unit, l-21, is 2.2
Assuming that there is some obstacle at point m, the IJ reflected pulse will enter the receiver 24 approximately 12.9 ms after the ultrasonic pulse is sent. This pulse is applied to each of the circuits 55 to 6 described above.
1, it is amplified, detected and shaped, and is supplied as a pulse PE to the reset terminal /-It of the flip-flop 62. This flip-flop 62 receives a clock pulse C
T' ii is set, and this pulse P
As a result of being reset by E, the Q terminal is at a high level from the rise of clock pulse CP to the time when pulse PE is generated (when the reflected pulse arrives).

On the other hand, since the reference distance pulse generation circuit 64 generates the reference distance pulse RP as shown in FIG. 6 in response to the rising edge of the delayed clock pulse CPd, the Q terminal of the flip-flop 62 becomes high level. While this pulse RP passes through the AND circuit 65 and the counting circuit 66
The number of pulses counted during this period is "22". This count value "22" is latched by the latch circuit 67 at the rising edge of the pulse PL which is further delayed by 70 ms from the delayed clock pulse CPd, and this value is displayed on the distance display element 2 as shown in FIG. Note that, as described above, the counting circuit 66 is reset when the clock pulse CP becomes low level, and performs the counting operation again from the next rise of the clock path CP.

Further, the intermediate stable multivibrator 70 generates a pulse PA of the pulse TA corresponding to the resistance value of the VR rotated by the knob 4 and the capacitance of the capacitor C in response to the rise of the delayed clock pulse CPd. If the set distance is, for example, 70 cm, this pulse TA will be 0.41 ms. Therefore, if an obstacle enters within 70 cm, pulse PE will arrive while pulse PA is at a high level. In such a case, the AND condition of the AND circuit 71 is satisfied, and the alarm speaker 3 emits an alarm sound for a predetermined period of time.

[Effects of the Invention] As explained above, according to the obstacle distance detection device according to the present invention, the distance between the wave transmitting/receiving unit and the obstacle can be accurately and quickly recognized. It is possible to accurately prevent various accidents caused by obstacles.

If the embodiment is adopted, the brightness of the distance display element can be adjusted during the day and at night, and the device can be operated only when reversing.

[Brief explanation of the drawing]

1 to 6 show an embodiment of the obstacle distance detection device of the present invention, in which FIG. 1 is a perspective view of the main body, FIG. 2 is a rear perspective view of the main body, and FIG. 3 is a wave transmitting/receiving unit. Figure 4 is a perspective view of the vehicle, Figure 5 is an electrical circuit block diagram,
FIG. 6 is a polyy-free chart of an electric circuit. 2... Display section, 23... Wave transmitting section, 24
... Wave receiving section, 52-54... Ultrasonic signal generating section, 55-61
...Amplification detection section, 64...Distance pulse generation section, 66...
Counting section.

Claims (1)

[Claims] a clock signal generating section; an ultrasonic signal generating section that generates an ultrasonic signal of a predetermined width according to the clock signal; a transmitter that sends out an ultrasonic wave in a predetermined direction according to the ultrasonic signal; a receiver for receiving ultrasonic waves, an amplification/detection unit for amplifying and detecting an output signal of the receiver, and a pulse generation unit for generating reference distance pulses at time intervals corresponding to a predetermined distance round trip time of the sound waves; a counting unit that counts the reference pulses from sending out the ultrasonic waves to receiving the reflected waves;
An obstacle distance detection device comprising: a display section that digitally displays the count value of the counter section.