JPS6341120B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a collision prevention device for an automobile, and an object of the present invention is to provide a collision prevention device for an automobile that can issue an appropriate collision prevention warning depending on the driving situation.

Examples will be described below using figures. FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention. Reference numeral 2 denotes a distance sensor that detects when an object M approaches a detection area within a certain distance from the vehicle body 1, and is installed at the rear of the vehicle body 1. It is designed to detect the approach of an object M from behind. 3 is an alarm means that is activated when the object detection signal V _p is output from the distance sensor 2, and 4 is a detection area switch that switches the detection area in conjunction with the operation (gear change) of the transmission 5 that sets the gear ratio. means, and in the embodiment, the transmission 5
The detection area is set at a relatively short distance (approximately 2m to 0.5m) to detect obstacles that may cause a collision when reversing, and when the is operated to the neutral or forward side, the detection area The system is set at a relatively long distance (20m to 0.5m) to detect the approach of a following vehicle, and an appropriate collision prevention warning is always issued depending on the driving situation. . In addition, three types of detection areas are set at each operating position of the transmission 5 (reverse, neutral, or forward), and the alarm means 3 issues an alarm corresponding to each detection area. ing.

The specific configuration will be explained below based on FIGS. 2 to 4. In the figure, 10a is a long-distance transmitter/receiver consisting of a transmitter T _a and a receiver R _a whose directivity for transmitting and receiving ultrasonic waves is narrowed (X in Figure 2).
0b is a short-distance transducer consisting of a transmitter T _b and a receiver R _b with wide directivity for transmitting and receiving ultrasonic waves (Y in FIG. 2). However, in the example, vehicle body 1
A long-distance transducer 10a is attached to the center of the rear part of the vehicle, and short-distance transducers are attached to both left and right ends of the rear part. Reference numeral 11 designates a wave transmitting circuit, which includes a long-distance synchronizing signal generating circuit 12a that generates a reference pulse V sa with a pulse width of t ₀ and a relatively long period t _a , and a long-distance synchronizing signal generating circuit 12 a that generates a reference pulse V _sa with a pulse width of to' and a relatively short period t. a short-distance synchronization signal generation circuit 12b that generates a reference pulse V _sb of _b ;
A tone burst oscillator circuit 13 generates a 40KHz tone burst signal V _T in synchronization with the reference pulses V _sa , V _sb ), and the tone burst signal V _T is amplified in power and sent to the transmitters T _a and T _b . It is composed of a power amplification circuit 14. 15 is a wave receiving circuit section, which includes an amplifying circuit 16 that amplifies the output V _R of the wave receivers R _a and R _b ;
A detection circuit 17 that detects the amplification circuit 16 output V _R ′ and outputs a pulse signal V _D , and a long-distance detection area.
Distance gate signal to set A ₁ , A ₂ , A ₃
A long-distance distance gate signal generation circuit 18a that generates V _A1 , V _A2 , V _A3 based on the output timing signal V _t of the tone burst signal V _T and short-distance detection areas B ₁ , B ₂ , B _{For example , in FIG .} OR circuit OR and AND circuit AND
Distance judgment circuits 19 ₁ , 19 ₂ , 19 formed by
It consists of ₃ . The distance sensor 2 is composed of the above-mentioned transducers 10a and 10b, a wave transmitting circuit section 11, and a wave receiving circuit section 15 _.
Alternatively, the reflected wave of the ultrasonic wave emitted from T _b is received by the receiver R _a or R _b within the preset time using the distance gate signals V _A1 , ~V _A3 , V _B1 ~ V _B3 At this time, object detection signals V _p1 to V _p3 are output.

20 _a1 to 20 _a3 , 20 _b1 to 20 _b3 are alarm means 3
Each alarm circuit 20 _a1 ~
20 _a3 , 20 _b1 to 20 _b3 are distance determination circuits 19 ₁ to 19
₃ , each has a different volume or tone, and is activated when the object detection signals V _p1 to V _p3 are output. 21
is a reverse detection switch that is turned on when the transmission 5 is operated in the reverse direction, and the detection area switching means 4 is constituted by a switching relay 22 that is activated when the reverse detection switch 21 is turned on. By switching the contacts R ₁ to _{R 7} of the switching relay 22 from the a side to the b side, the detection area is switched from a long distance to a short distance.

Below, the operation of the embodiment will be explained in Figures 5 and 6.
This will be explained in detail with reference to the drawings. Now, when the transmission 5 is operated to the neutral or forward position, the reverse detection switch 21 is turned off and the contacts _R1 to _R7 of the changeover relay 22 are set to the a side.
The signal waveforms of each part in this state are as shown in _FIG .
The tone burst oscillation circuit 13 operates in synchronization with V _sa and generates a 40 KHz tone burst signal V _T . The transmitter _T a of the long-distance transducer 10a is excited by the signal V _T ′ obtained by power amplifying the tone burst signal V _T by the power amplifying circuit 14, and the ultrasonic pulse is generated at a constant period t _a. fired. The emitted ultrasonic pulse is reflected by an object M behind (for example, a following vehicle). This reflected wave is received by the receiver R _a and amplified by the amplifier circuit 16, and the signal V _R output from the amplifier circuit 16 is a direct wave from the transmitter T _a to the receiver R _a . The wrap-around signal P _p caused by P p and the reflected signal caused by the reflected wave
Contains _P1 . The pulse signal V _R ′ obtained by detecting this signal V _R also includes a wrap-around signal pulse P _p ′ in addition to the reflected wave signal pulse P ₁ ′. on the other hand,
The rising and falling times t ₁ , t ₂ , t 3 , and t ₄ of the distance gate signals V _A1 , V _A2 , and V _A3 for setting the detection areas A ₁ , A ₂ , and A ₃ are based on the speed of sound in _vm /sec. Then, t ₁
= la ₁ /v, t ₂ = la ₂ /v, t ₃ = la ₃ /v, t ₄ = la ₄ /v, and in the example, la ₁ = 0.5 (m), la ₂ = 5 ( m),
la ₃ = 10 (m) and la ₄ = 20 (m).
Here, in the case of Fig. 5, the distance gate signal V _A1
Since the reflected wave signal pulse _{P1 '} is obtained in _{the H} level section _of A loud or tonal warning will be issued to indicate that the area is within 0.5 to 5 meters. Similarly, when the reflected wave pulse signal P ₁ ' is obtained in the H level section of the distance gate signals V _A2 and V _A3 , object detection signals V _p2 and V _p3 are output from the distance judgment circuits 19 ₂ and 19 ₃ . and alarm circuits _20a2 , _20a3
is activated and the object M is detected in the detection area _A2 , (5m~10
m), a loud or tonal alarm is issued to indicate that the detection area is within the detection area A ₃ (10 m to 20 m). Therefore, based on the volume or tone of the alarm, the driver can recognize that a vehicle approaching from behind has entered each detection area A ₁ , A ₂ , A ₃ , and is always aware of the following when driving normally or waiting at a traffic light. This allows you to accurately determine the distance between you and the vehicle.

Next, when the transmission 5 is operated to the reverse position, the reverse movement detection switch 21 is turned on and the contacts R ₁ to R ₇ of the changeover relay 22 are set to the b side.
The signal waveforms of each part in this state are as shown in _FIG . Ultrasonic pulses are emitted at a constant period tb from the transmitter _Tb of the distance transducer 10b. The emitted ultrasonic waves are reflected by an object M (obstacle) behind. This reflected wave is received by the wave receiver _Rb , amplified by the amplifier 16, and detected by the detection circuit to output a pulse signal V _R '. Here, the rising and falling times t _{1 ′ ,} t ₂ ′, t ₃ ′, t ₄ ′ of the distance gate signals V _A1 , V _A2 , _{V A3 for} setting the detection areas B 1 , B ₂ , B 3 are for example,
Detection area B ₁ is 0.5m or less, detection area B ₂ is 0.5m or less
1 m, and the detection area _B3 is set to 1 to 2 m. However, t ₁ ' is set immediately after the point in time when the loop signal pulse P ₀ ' disappears. Here, in the case of FIG. 6, since the reflected signal pulse P ₁ ' is obtained in the H level section of the distance gate signal V _B1 , the object detection signal V _p1 is output from the distance judgment circuit ₁₉₁ , and the alarm circuit 20 _b1 is activated to issue a volume or tone alarm indicating that the object M is within the detection area _B1 , that is, within a range of 0.5 m or less. Similarly, if the reflected wave pulse signal P ₁ ' is obtained in the H level section of the distance gate signals V _A2 and V _A3 , the distance judgment circuit 1
The object M from 9 ₂ and 19 ₃ is detected in the detection area B ₂ (0.5 to 1
m), a loud or tonal warning is issued indicating that the vehicle is within the detection area B ₃ (1 to 2 m), and based on the loudness or tone of the warning, the driver is able to detect the presence of an object M that may pose an obstacle when reversing. This means that the distance to M can be accurately determined.

As described above, the present invention is attached to the vehicle body 1,
A distance sensor 2 that detects when an object M approaches a detection area within a certain distance from the vehicle body 1, and a detection area switching device that switches the detection area of the distance sensor 2 in conjunction with the operation of a transmission 5 that changes the gear ratio. 4, and an alarm means 3 for notifying that an object M has approached within the detection area.The detection area switching means 4 sets the detection area according to the gear ratio to the distance sensor 2, and 2
When an object detection signal is output from the alarm means 3
It has the advantage that the detection area is automatically switched depending on the driving situation, and an appropriate collision prevention warning is always issued. Since a plurality of detection areas are set and an alarm means for emitting a corresponding alarm for each detection area is provided, there is an advantage that the distance to an object that may collide can be accurately grasped.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of an embodiment of the present invention, FIG. 2 is a top view of the same, FIG. 3 is a block circuit diagram showing a specific configuration of the same, and FIG. 4 is a main circuit of the same. FIG. 5, and FIG. 6 are explanatory diagrams of the same operation. 1 is the vehicle body, 2 is the distance sensor, 3 is the alarm means, 4
5 is a detection area switching means, and 5 is a transmission.

Claims (1)

[Claims] 1. A distance sensor 2 which is attached to the vehicle body 1 and detects when an object M approaches a detection area within a certain distance from the vehicle body 1, and which is linked to the operation of a transmission 5 that changes the gear ratio. The detection area switching means 4 is configured to switch the detection area of the distance sensor 2 by changing the detection area of the distance sensor 2, and the alarm means 3 is configured to notify that an object M has approached the detection area. A collision prevention device for an automobile, characterized in that a detection area is set in a distance sensor 2, and an alarm means 3 is activated when an object detection signal is output from the distance sensor 2. 2. The detection area switching means 4 is formed so that a plurality of detection areas can be set at each operating position of the transmission 5, and the alarm means 3 is formed so as to issue different alarms corresponding to each detection area. A collision prevention device for an automobile according to claim 1, characterized in that: