JPS6073478A - Rear obstacle detector for vehicle - Google Patents

Abstract

PURPOSE:To detect the position of an obstacle over the entire obstacle detection area through one ultrasonic transmitter-receiver by turning the transmitter- receiver which has ultrasonic wave oscillators around a support shaft erected freely turnably in a rear vehicle part, and swiveling the ultrasonic wave oscillators to scan in the obstacle detection area. CONSTITUTION:The ultrasonic wave transmitted and receiver 1 is constituted by arranging a couple of ultrasonic wave oscillators at radially symmetrical positions of the support shaft erected rotatably in the rear vehicle part. A rotary scanning mechanism 2 including a motor swivels the oscillators alternately to scan toward the obstacle detection area behind the vehicle. A sonar circuit 3 calculates the distance to the obstacle. An encoder 4 generates an angle pulse signal 4a every time the transmitter-receiver 1 rotates by a specific angle. A reference angle detecting circuit 5 generates a reference angle signal 5a when detecting a reference angle. An angle interface circuit 6 counts the angle pulse signal 4a to know the scanning angle position of the transmitter and receiver 1 and also outputs an ultrasonic oscillation trigger signal 6a to the sonar circuit 3 to display the distance from each scanning angle position of the transmitter- receiver 1 to the obstacle on a display device 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a middle-duty rear obstacle detection headpiece that detects the distance to obstacles on both sides of the Φ, and detects the distance to the obstacle by detecting the foul time of ultrasonic waves from the obstacle. I tried to know the proximity distance II
This is similar to a sonic obstacle detection device.

Conventional ultrasonic obstacle detection devices have one or more ultrasonic transducers fixedly installed in a predetermined direction at the center of the bumper at the rear of the vehicle or at left and right positions. It is only possible to detect obstacles in a specific direction.In order to detect all obstacles within the obstacle detection area behind the vehicle, it is necessary to install a large number of ultrasonic transducers in parallel on the Bamba soil, but this is expensive. It is unrealistic from both a financial and a practical standpoint.

The present invention has been made in view of the above problems, and uses a single ultrasonic transducer to detect obstacles and objects that can detect the position of obstacles in the entire obstacle detection area behind the vehicle. The purpose of this invention is to provide a detection device.

In order to achieve this object, the detection device of the present invention includes an ultrasonic transducer that is rotatably installed at the rear of a vehicle and has an ultrahigh wave transducer arranged around an Iζ support shaft; a scanning means that rotates the ultrasonic transducer to rotate and scan an obstacle detection area behind the vehicle; and a scanning means that oscillates ultrasonic waves via the ultrahigh wave transducer at the same scanning angle and covers obstacles. The apparatus is equipped with a distance detecting means for receiving a reflected wave from an object and detecting the distance to the obstacle from the time of ultrasonic oscillation to the reception of the ultrasonic wave.

By the way, in such a detection device, it is important to accurately know the scanning angle position of the ultrasonic transducer. The detection device of the present invention further includes angular pulse generating means for emitting an angular pulse (,', J) every time the ultrasonic transducer rotates by a predetermined angle, Disconnection means for temporarily cutting off the connection between the ultrasonic transducer and the distance detection means when entering the detection area, and a detection means for detecting a disconnection caused by the disconnection means and setting the reference angle signal to R. , an angle calculation means for counting the angle pulse signal after inputting the reference angle signal to know the scanning angle position of the ultrasonic transducer, thereby realizing an inexpensive and compact scanning angle detection means.

Below 1: The present invention will be explained with reference to illustrated embodiments.

Fig. 1 shows the overall outline of the present invention. In the figure, '1' is an ultrasonic transducer, and a pair of ultrasonic vibrations are placed at radially symmetrical positions on a support shaft rotatably installed at the rear of the vehicle. I will have a child. Reference numeral 2 denotes a rotation scanning mechanism including a motor, which rotates the support shaft to rotate and scan the ultrasonic transducer alternately toward an obstacle detection area at the rear of the vehicle.

3 is a sonar circuit which is a distance detection means, which receives and transmits ultrasonic waves at a predetermined scanning angle via the ultrasonic transducer 1, and detects failures based on the time required to receive the reflected waves after transmitting the ultrasonic waves. The distance to the thing stems out. /I is an angular pulse generating means that generates an angular pulse signal 4a (see FIG. 5 (1)) every time the transducer 1 rotates by a predetermined angle (11.25° in this embodiment). 5 is a reference angle detection circuit to be described later, which emits a reference angle signal 5a (see FIG. 5 (2)) when a square claw is detected.

6 is an angle internoace circuit which is an angle calculation means,
After the top-distributed semi-angle signal 5a is input, the angle pulse signal 4a is inputted from 1 to 1 to determine the position of the scanning claw of the transducer 1, and at each angle position, the angle pulse signal 4a is input to the circuit 3. Outputs number 68 to the sonic oscillation trigger. 7 is a display device that displays the distance to the obstacle at each scanning angle position of the transducer 1, so that the -C driver can recognize the position of the obstacle in the entire obstacle detection area behind the vehicle. can.

Figure 2 shows the ultra 8-wave transducer 1 mounted on the rear bumper of the vehicle.
This indicates a state where the temperature is low. Transducer/receiver 1 is Takesuke 15
The ultrasonic transducer 11a is attached to the tip of the arm that extends symmetrically in the radial direction.
(only one shown) is built-in 1, vibrator 11
a J: Re-release! The ultrasonic waves are reflected by the reflective surface 17 formed on the side of the transducer 1! Jil L! The reflected wave from the obstacle is also reflected by the reflecting surface 17 and returns to the vibrator 11a.

The J support shaft 15 is made of J, S4111 on the T-Y and G17! ,: The ultrasonic transducers 11a are rotated by the co-rotating scanning mechanism 2, and the ultrasonic transducers 11a are alternately directed toward the obstacle detection area at the rear of the vehicle.

On the outer periphery of the large diameter portion of the support shaft 15, band-shaped electrodes 12.13, which serve as disconnection means 4111, are formed in parallel, and the brushes 14a and 14b are brought into contact with and electrically connected to these electrodes, respectively. The strip electrodes 12, 13 are connected to the ultrasonic transducer 11a, and the brushes 14a, 14b are connected to the external sonar circuit 3 (see FIG. 1) by lead wires. Further, the lower end of the support lI'llll 15 is integrally connected to the encoder 4. FIG. 3 schematically shows the structure of the electrodes 12, 13. In the figure, 11b is the remaining single-power ultrasonic transducer. Here, the electrode 13 is divided halfway around the circumference with a predetermined gap f, forming divided electrodes 13a and 13b. Therefore, the brush 14b moves the divided electrode 1 to the receiving side every half rotation of the support shaft.
3a and 13b are electrically connected, thereby each electrode 13
When the energization of the transducers 11a and 11b connected to the oscillators 11a and 13b is switched, the energization switching station, that is, when either of the oscillators 11a or Ilb enters the obstacle detection area, the gap f is constant. Which vibrator 11a during time T
, , 11b is also not connected to the sonar circuit 3 and becomes disconnected.

FIG. 4 shows the structure of the reference position detection circuit 5.

The detection circuit 5 includes an amplifier 51. Detector 52, comparator 53, flip flop 5j5) and ΔAND game 154
．． It consists of 56 pieces. 31 in the diagram is installed in Sono circuit 3/j
Transmission/reception (Ht/J switch. 32 is an oscillator and jQ
I will. 1. The receiving section of the sonar circuit 3 is not shown in the figure.

Hereinafter, the operation of the detection circuit 5 will be explained with reference to FIG.

As shown in Figure 15 (1), the support shaft of the ultrasonic transducer 1 is 11.25cm from the encoder 4 (see Figure 1).
An angular pulse signal /la is output to fU which rotates by degrees.

At this time, as mentioned above, half a rotation frj of the support shaft is l18+
During this period, the connections between the vibrators 11a and 11b and the sono circuit 3 are cut off. The detection circuit 5 detects this disconnection state and outputs a reference angle signal 5a every half rotation of the support shaft as shown in FIG. 115 (2).

Line I3, as shown in Figure 5 (3), the angle pulse No. 18 4a is the oscillator of the sonar circuit 3;) 2 J, 11' is the two-frequency pulse signal 3.
28 is transmitted, and a super&wave 1r'=U is emitted via the transducer 1. After the ultrasonic wave is emitted, select switch 3
1 switches to the receiving f, 'J side (the state shown in Figure 4), but at this time, the transducer 1 receives the reverberation after ultrasonic oscillation for a while]
No ((13, therefore, from the detector 52, FIG.
4), a balance signal 52a is output.

Therefore, the reverberation signal 52a is obtained only when either the ultrasonic transducer 11a or 11b is connected to the sono-circuit 3. -1- Note (When iJi No. 528 reaches a predetermined level or higher, it passes through the comparator 53 and is manually applied to Goos 1 to 54. Goos 1 to 54 are supplied with the beam 1-1 Tsuku Pulse CP1 (KO
5 (see Figure 5 (5)) is manually powered, and the pulse C[]1 is the signal 540 only on the platform where the reverberation signal 52a is manually powered].
(See Figure 5 (6))
I got it and hit it. Above flip] -1/' 5! j IJ is periodically reset by the 1-pulse CP2 (see Figure 5 (7)), and as a result, +J55a becomes the 55th output from the Q terminal of A.
In Figure (8), when inputting the sword J and the sea urchin pulse CP2, “1” is displayed.
Level roar, Juki Shinyuri 4a man power 11.1 r O
What about J level? .

Here, as is known from the figure, when the reverberation signal 52a is not manually applied, the first signal 558 continues at the "1" level,
During this time, input to the goo 156 or ['i Tsuk Pulse CI
) 3 (see FIG. 5 (9)) is outputted to the angle interface circuit 6 (see FIG. 1) as the t W QE horn plug detection signal 5a shown again in FIG. 55 (10).

Every time the ultrasonic transducer 1 rotates half a turn and the connection of the pair of ultrasonic transducers 11a, 111 (see Fig. 3) installed thereon is switched to AC. , Kiha (
An angle signal 85a is output, and the angle internorth circuit 6 (see Fig. 1) inputs the angle pulse signal 4a following the signal 58, so that the angle signal 85a is turned toward the obstacle detection area. The scanning angle I of the transducers 11a and 11b accurately determines the vehicle position.

In the above embodiment C, the energization of the ultrasonic transducer facing the obstacle detection area is switched to alternating direction 77, and the reference angular position is determined by detecting the state of the first line at the time of this switching. In contrast, one ultrasonic vibration T is directed toward the obstacle detection area.
A method (i) for reducing the return time is considered, and in this case, one stage of wire breakage is configured so that a wire breakage occurs at each rotating end of the ultrasonic transducer.

As described above, the vehicle rear obstacle detection device of the present invention is rotatably installed at the rear of the vehicle. ,: An ultrasonic transducer is constructed by arranging an ultrasonic transducer around the insect holding axis, and the transducer is rotated μ (- the ultrasonic transducer is rotated to the obstacle detection area behind the vehicle). By scanning U, a single ultrasonic transducer can detect the position of obstacles in the entire obstacle detection area, allowing the vehicle to move backward safely and smoothly. The entire edict is a simple song.

Further, according to the scanning angle detection means of the present invention, it is possible to accurately know the scanning angle without causing errors due to hysteresis or malfunctions due to wear of the brush, as would be the case when using a voltmeter. It is cheaper than using an angle detector that directly outputs a digital value corresponding to the angle.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is a partial sectional view of the ultrasonic transducer installed on the bumper of a vehicle, and Fig. 3 is a partial cross-sectional view of the ultrasonic transducer installed on the bumper of a vehicle. Energization switching machine 4+'+
FIG. 4 is a block diagram showing the configuration of the reference angle detection circuit, and FIG. 5 is a timing diagram showing various signal waveforms in the circuit based on FIG. 4. 1...Ultrasonic transducer 2...Scanning means 31...Distance detecting means 4...Angle pulse generating means 5... Angle detection means 6...
・Angle Enkan - f stage

Claims (3)

[Claims] (1) An ultrasonic transducer consisting of an ultrahigh wave transducer arranged around a support shaft rotatably installed at the rear of the hollow body, and an ultrasonic transducer that rotates the ultrasonic transducer A scanning means rotates and scans an obstacle detection area at the rear of the vehicle, and transmits ultrasonic waves through the ultrasonic transducer at each scanning angular position, receives reflected liquid from the obstacle, and detects the ultrasonic light. 4r
Received from J: Put it in C! , :h distance detecting means for detecting the distance to the obstacle from between 1 and 11; angle pulse generating means for emitting an angle pulse signal to the ultrasonic transducer rotated by a predetermined angle; When the wave vibration enters the obstacle detection area, the connection between the ultra 8 wave receiver and the distance detection means is temporarily disconnected. r by disconnection means
The V angle 1α detection means detects fJ≦1 and lights up the Ql-use claw A3. , ilKakuma 11. A rear obstacle detection device for a vehicle, comprising angle calculation means for detecting the scanning angle position of an ultrahigh wave transducer by inputting the above-mentioned pulse signal after inputting the angle. (2) The disconnection means is connected to an electrode connected to the vibrator, formed in the fdh direction on the outer periphery of the support shaft of the ultrasonic transducer, and with the discontinuous portion located 1° to the right at a predetermined position, and the distance detection means. 4R by contacting and conducting the brush with the above electrode.
IJ1c, the above reference angle 1 good detection means + 61'' - 1θ
Φ dual-purpose rear obstacle detection device set forth in claim 11, item 1, which is set to detect the connection between the brush and the electrode of the i-line means (3) The reference angle detection means described in item 1 detects the non-conductivity between the brush and the electrode by receiving a residual charge signal from the vibrator immediately after transmitting the ultrasonic wave.
The rear 1'J obstacle detection device for a vehicle according to claim 2, which is set to detect the object by 'III i:'1
the law of nature.