JPH06242224A - In-vehicle obstacle detection device - Google Patents

Abstract

(57) [Summary] [Structure] The light source 9a is arranged parallel to the traveling direction R,
A symmetric lens 10a is placed in the traveling direction R on the optical path of the light source 9a.
Place vertically to. Further, the light source 9b is moved in the traveling direction R.
And a wide-angle lens 10b cut so as to emit a laser beam having high intensity on the left side and weak intensity on the right side on the optical path of the light source 9b. Only tilt it. Then,
The laser beam 16 emitted from the light source 9b is emitted asymmetrically with respect to the traveling direction R. [Effect] Even if the vehicle is mounted on the front side of the vehicle, obstacles near both sides of the vehicle can be reliably detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle-mounted obstacle detecting device which is mounted on a vehicle and is used to detect an obstacle by emitting an electromagnetic wave such as a laser beam in a forward direction.

[0002]

2. Description of the Related Art Conventionally, in order to prevent a collision accident between vehicles on a highway, a contact accident due to an unreasonable overtaking or a lane change, etc., an optical detector automatically detects obstacles such as other vehicles automatically. The obstacle detection device for detection is mainly used by being mounted on a large truck that travels on a highway or the like.

FIG. 8 is a conceptual diagram showing a typical prior art of the obstacle detecting device (sensor technology Vol. 11 No. 10).
See the October 1992 issue). In this prior art, a large truck (hereinafter referred to as "own vehicle") 100 has a depth of about 17 cm (width of about 20 cm, height of about 80 c) in the front center.
The laser radar 101 of m) is attached. This laser radar 101 has three light sources (not shown) for emitting a laser beam 102. From these three light sources, a laser beam 102 for detecting a vehicle 103 in front of the own vehicle 100 as shown in FIG.
Laser beams 102b and 102c for detecting a vehicle (not shown) ahead of both sides of the host vehicle 100, for example, an interrupting vehicle are emitted. The laser beam 102a is a laser beam having directivity symmetrical with respect to the central front direction, and the laser beams 102b, 1b
Reference numeral 02c is a laser beam having a directivity symmetrical with respect to the left and right diagonal forward directions. Therefore, the laser beams emitted from the three light sources are generally emitted symmetrically with respect to the central front direction. Also, this laser radar 1
01 is equipped with a sensor unit (not shown) that receives the reflected light 104 reflected by a reflector (not shown) mounted on the rear surface of the vehicle 103 in front of the front. In the following description, the laser beam 102a is referred to as "main beam 102a", and the laser beams 102b and 102c.
Are referred to as "side beams 102b and 102c", respectively.

In this structure, of the light sources provided in the laser radar 101, when the main beam 102a emitted from a predetermined light source is reflected by a reflector mounted on the rear surface of the vehicle 103, the reflected light is reflected. 104 is received by the sensor unit. Then, the received reflected light 10
The received signal corresponding to No. 4 is subjected to appropriate processing, and the vehicle 10
The distance up to 3 is calculated, and when this distance is shorter than the safe inter-vehicle distance, the driver is notified of the presence of this vehicle 103 by an alarm device (not shown). Also, the side beam 102
Even when b and 102c are reflected by the reflectors mounted on the rear surface of the vehicle traveling in the other lanes on the front sides of the vehicle 100, the presence of the vehicle is not shown in the figure as in the above case. The driver is notified by an alarm.

[0005]

SUMMARY OF THE INVENTION In the above-mentioned prior art,
A laser radar 101 that emits a laser beam 102 is attached to the center of the front surface of the own vehicle 100. However, for example, in the case of a vehicle (front engine vehicle) that has a prevailing engine room in the front, the laser radar 101 cannot be attached to the center of the front surface. That is,
In front engine vehicles, the engine occupies the center of the engine room and the radiator intake for cooling the engine is located in the center of the front of the engine room.
It is very difficult to mount the laser radar 101 having a width of about 20 cm and a height of about 8 cm.

On the other hand, there is a little space near the left and right sides of the front engine vehicle compared to the center of the front of the engine room, and it is conceivable to mount the laser radar 101 in this space. However, for example, when the laser radar 101 is mounted in the space on the front right side toward the front center direction, the laser beam emitted from this laser radar 101 is symmetrical, so that the side beam 102b on the right side is formed as shown in FIG. The detection limit distance becomes long, and the detection limit distance of the left side beam 102c becomes short. That is, as shown in FIG. 10, in the side beam 102b, the vehicle 111 that changes lanes from the lane 123 two lanes next to the lane 121 in which the vehicle 100 is traveling to the lane 122 one lane next to the lane 121 is It may be erroneously recognized as an interrupt to 121 and detected. Also, side beam 1
In 02c, lane 120 is one lane next to lane 121.
It may not be possible to detect the vehicle 112 that enters the lane 121 from the vehicle. Therefore, it is not possible to reliably detect a vehicle that comes in from both front sides of the host vehicle 100.

Further, since a general car has a narrower field of view than a large-sized truck, it is difficult for the driver to confirm the state on the passenger side. Therefore, when the laser radar 101 is attached to the driver's seat side on the front side, the detection limit distance becomes excessive and insufficient, so that it is not possible to reliably detect the vehicle interrupting from the passenger seat side. Even if you visually check the vehicle, it takes more time to check it than in the case of a large truck, so it is easy to cause a contact accident. For this reason, there has been a demand for an obstacle detection device that can reliably detect the vehicle even when the laser radar 101 is attached to the front driver's seat side of a general vehicle.

Therefore, an object of the present invention is to solve the above-mentioned technical problems and to reliably detect an obstacle near both sides of the vehicle even when the vehicle is mounted at a position on the front side of the vehicle. An object of the present invention is to provide an obstacle detection device.

[0009]

According to a first aspect of the present invention, there is provided an on-vehicle obstacle detecting device for emitting an electromagnetic wave, and receiving a reflected wave of the electromagnetic wave from the emitting means. A vehicle-mounted obstacle detection device having a receiving means for detecting an obstacle based on a received reflected wave,
The emitting means has an acute angle and symmetrical directivity, and has an obtuse angle and asymmetric directivity with the first emitting portion that emits an electromagnetic wave of relatively strong intensity, and is relatively weak. And a second emitting portion for emitting a strong electromagnetic wave.

The on-vehicle obstacle detecting device according to the second aspect of the invention detects the obstacle based on the emitting means for emitting the electromagnetic wave, the reflected wave of the electromagnetic wave from the emitting means, and the received reflected wave. A vehicle-mounted obstacle detection device having a receiving means for controlling the vehicle, wherein the receiving means has a first receiving portion having an acute angle and symmetrical directivity and relatively high receiving sensitivity, and an obtuse angle, and And a second receiver having asymmetric directivity and relatively low reception sensitivity.

[0011]

In the structure according to the above-mentioned claim 1, the strong electromagnetic waves are symmetrically emitted in the front of the front of the vehicle at the first emission portion. Then, the emitted electromagnetic wave is reflected by an obstacle far away from the front, the reflected wave is received by the receiving means, and the obstacle far away from the front is detected by the receiving means based on the received reflected wave.

On the other hand, the electromagnetic wave 202 as shown in FIG. 6 (a) is emitted asymmetrically at the second emitting portion. FIG. 6A shows a case where the emitting means 201 is provided on the right side of the traveling direction R of the vehicle 200. The electromagnetic wave 202 emitted from the second emission unit has a radiation intensity in the vicinity of the left side that is stronger than a radiation intensity in the vicinity of the right side, so that the detection limit distances S1 and S2 from the center of the vehicle 200 are made substantially equal. be able to. Therefore, the electromagnetic wave 20
2 are obstacles 203 and 204 near both sides of the vehicle 200.
Based on the reflected waves from the obstacles 203 and 204, the obstacles 203 and 204 can be reliably detected even when the emitting means 201 is attached to the front right side of the vehicle 200.

Further, at the second emitting portion, an electromagnetic wave 212 as shown in FIG. 6 (b) is emitted. Figure 6
(b) shows the emitting means 21 on the left side with respect to the traveling direction R of the vehicle.
The case where 1 is provided is shown. Since the electromagnetic wave 212 has a stronger radiation intensity in the vicinity of the right side than that in the vicinity of the left side, the detection limit distances S1 and S2 from the center of the vehicle 210 can be made substantially equal in this case as well. Therefore, the electromagnetic wave 212 is reflected by the obstacles 213, 214 near both sides of the vehicle 210, and the obstacles 213, 2
Based on the reflected wave from 14, even if the emission means 211 is attached to the front left side of the vehicle 210, those obstacles 2
It is possible to reliably detect 13, 214.

According to the second aspect of the present invention, the first receiving section receives the reflected wave from the obstacle located in the front and front of the vehicle and at a distance. Then, on the basis of the received reflected wave, an obstacle located far away from the front is detected by the receiving means. On the other hand, in the second receiving unit, for example, as shown in FIG.
A reflected wave 222 as shown in is received. Figure 7 (a) shows
The receiving means 221 is provided on the right side with respect to the traveling direction R of the vehicle 220.
Is shown. The second receiving unit receives the reflected waves from the obstacles 223 and 224 within the distances S1 and S2 from the center of the vehicle 220 because the receiving sensitivity on the left side is relatively high and the receiving sensitivity on the right side is relatively low. can do. Therefore, based on this reflected wave 222, the vehicle 2
Even when the receiving means 221 is attached to the right side of the front of 20,
Obstacles 223 and 224 near both sides of the vehicle 220 can be reliably detected.

The second receiving section receives a reflected wave 232 as shown in FIG. 7 (b), for example. Figure 7
(b) shows a case where the receiving means 231 is provided on the left side of the traveling direction R of the vehicle 230. The second receiver is
Since the reception sensitivity on the right side is relatively high and the reception sensitivity on the left side is relatively low, it is possible to receive the reflected wave 232 from the obstacles 233, 234 within the distances S1, S2 from the center of the vehicle 230. Therefore, based on this reflected wave 232, even when the receiving means 221 is attached to the left side of the front surface of the vehicle 230, the obstacles 23 near both sides of the vehicle 230
3, 234 can be reliably detected.

[0016]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a schematic view showing a simplified configuration of an on-vehicle obstacle detection device according to an embodiment of the present invention. This vehicle-mounted obstacle detection device 1 is used by being mounted on the right side of the front surface of a vehicle, and emits a laser beam 2 from the emission parts 3a, 3
b (hereinafter, collectively referred to as “emission unit 3”), the laser beam 2 is reflected by an obstacle 4 such as a vehicle, and reflected light 5 is received by a light receiving unit 6. The received reflected light 5 is subjected to appropriate signal processing in the signal processing unit 7 to detect the obstacle 4. The laser beam 2 emitted from the emission unit 3 may be a visible light laser beam or an infrared laser beam. Further, instead of emitting the laser beam 2, light from a light emitting diode (LED) may be used.

The emission section 3 has light sources 9a and 9b for emitting the laser beam 2 based on the signal from the emission drive section 8. An axially symmetric lens 10a and an asymmetrical lens 10b are provided near the light sources 9a and 9b on the optical path of the laser beam 2 emitted from each of the light sources 9a and 9b. The lens 10b is a lens cut so that the intensity of the laser beam 2 emitted in the left direction can be increased and the intensity of the laser beam 2 emitted in the right direction can be decreased, for example. However, the magnitude of strength may be opposite. In the following description, the lens 1
0a is called "symmetrical lens 10a", and lens 10b is called "wide-angle lens 10b".

The emission drive unit 8 has a signal generation unit 8a for supplying a laser drive signal to the signal switching unit 8b and a synchronization signal for a processing unit described later. In the signal switching unit 8b to which the laser drive signal is given from the signal generating unit 8a, based on the signal from the processing unit described later,
The light source 3 to which the laser drive signal is applied is switched. Then, a laser driving unit 8c for driving the light source 3
A drive signal is given to the light source 3 via the
Laser beams 2 are emitted alternately from 3b.

The light receiving portion 6 is a light receiving device 11 formed of a light receiving element such as a PIN photodiode (PD).
a and 11b, and light receiving lenses 12a and 12b for collecting the reflected light 5 on the respective light receivers 11a and 11b. The reflected light 5 that has entered through the light receiving lenses 12a and 12b is received by the light receivers 11a and 11b, and the reflected light 5 is converted into an electric signal by the light receivers 11a and 11b and provided to the signal processing unit 7. It The light receiving unit 6 and the signal processing unit 7 correspond to receiving means.

The signal processing section 7 has an amplifying section 7c for amplifying the signals provided from the light receivers 11a and 11b. The signal amplified by this amplifying section 7c is the signal switching section 7
b. The signal switching unit 7b selects which of the light receivers 11a and 11b to give the signal to the processing unit 7a based on the signal from the processing unit 7a.
a and 11b are switched. This switched receiver 1
When the signals from 1a and 11b are given to the processing unit 7a,
In the processing unit 7a, based on the given signal, the obstacle 4
The distance to is calculated.

More specifically, the processing section 7a has a distance counter (not shown) for calculating the distance to the obstacle 4. A synchronization signal is given to the distance counter from the signal generator 8a, and the distance is calculated by giving a signal corresponding to the reflected light 5 from the obstacle 4 to the processor 7a after the laser drive signal is generated. It is based on the time to.

FIG. 1 is a diagram showing a specific arrangement example of the emitting section 3. In this figure, a light source 9a and a symmetric lens 10a are used as a first optical system, and a light source 9b and a wide-angle lens 10b are used as a second optical system. In the first optical system, the light source 9a is arranged in the traveling direction R of the vehicle, and the symmetric lens 10a has the light source 9a.
It is installed very close to. Further, in the second optical system, the light source 9b is obliquely arranged at a predetermined angle θ with respect to the traveling direction R, and the wide-angle lens 10b is also installed obliquely at an angle θ with respect to the traveling direction R near the light source 9b. ing.

When the first optical system and the second optical system are arranged in this way, as shown in the drawing, a laser beam 15 is emitted from the first optical system and a laser beam 16 is emitted from the second optical system. That is, the laser beam 15 is emitted from the light source 9a at an acute angle and symmetrically with high intensity, and is emitted to a relatively distant place (for example, 100 m). Further, the laser beam 16 is emitted from the light source 9b at an obtuse angle with a weak intensity, and is emitted relatively near. Further, the laser beam 16 has a fan-shaped spread which is asymmetric with respect to the traveling direction R because the light source 9b is arranged at an angle θ with the traveling direction R, and the beam width thereof is usually the width of the road ( It is about 3.5 m). In this way, the emitting unit 3 functions as an emitting unit, the first optical system functions as a first emitting unit, and the second optical system functions as a second emitting unit. Note that the above-mentioned angle θ may be adjustable with, for example, a screw.

3 and 4 are views for explaining a specific example of obstacle detection in the vehicle-mounted obstacle detection device 1. In FIG. 3 (a), the driver's seat is on the right side, and the vehicle-mounted obstacle detection device 1 is installed at a position 21 on the front right side of the vehicle 20 so that the emission part 3 and the light receiving part 6 are on the right side and the left side, respectively. is there. When the driver's seat is on the left side, the emitting section 3 and the light receiving section 6 may be mounted by reversing the left and right so that they are on the left side and the right side, respectively.

The vehicle 20 and the vehicle 22 in front of the vehicle 20 are in the lane 40, the vehicle 23 is in the lane 41 to the left of the lane 40, and the vehicle 24 is in the lane 43 to the right of the lane 40. It is running. In addition, 1 of lane 40
The lane next to the right is lane 42. Further, the shape of the laser beam 16 is a shape protruding to the front left side, the width thereof is about the width of the road (about 3.5 m), and the laser beam 15 is about 100 m in the traveling direction of the vehicle 20. It is a degree.

In such a situation, as shown in FIG. 3 (b), when the vehicle 23 cuts in from the lane 41 to the lane 40, the second optical system is arranged to project to the front left side of the vehicle 20. Since the laser beam 16 is emitted by
The laser beam 16 is reflected by a reflector mounted on the rear surface of the vehicle 23. Then, the reflected light is received by the light receiving unit 6, the electric signal corresponding to the reflected light is provided to the signal processing unit 7, and the vehicle 23 is detected.

Further, as shown in FIG. 3 (c), when the vehicle 22 slows down and moves backward relative to the vehicle 20, the laser beam 15 is emitted from the first optical system in front of the vehicle 20. Since the laser beam 15 is emitted, it is reflected by the reflector mounted on the rear surface of the vehicle 22. At this time, the on-vehicle obstacle detection device 1 is attached to the position 21 on the right side of the vehicle 20, and since the reflectors are usually mounted on the left and right sides of the rear surface of the vehicle, the laser beam 15 is well reflected by the reflector. To do. Then, the reflected light is received by the light receiving unit 6, an electric signal corresponding to the reflected light is provided to the signal processing unit 7, and the vehicle 22 is detected.

Further, as shown in FIG. 4 (a), when the vehicle 24 changes from the lane 43 to the lane 42, the laser beam 16 from the second optical system does not protrude to the front right side of the vehicle 20 so much. . Therefore, even if the vehicle 20 changes from the lane 43 to the lane 42, the vehicle 24 is not detected because it is outside the detectable range of the laser beam 16. On the other hand, as shown in FIG. 4 (b), when the vehicle 24 has changed into the lane 42 and then interrupted the lane 40, at this time, the vehicle 24 has moved into the detectable range of the laser beam 16. Therefore, the laser beam 16 is reflected by the reflector mounted on the rear surface of the vehicle 24, and the vehicle 24 is detected based on the reflected light.

As described above, according to the present embodiment, the vehicle-mounted obstacle detection device is attached to the inside of the front surface on the right side of the vehicle, the obtuse angle from the second optical system, and the radiation intensity on the left side is higher than that on the right side. Since the laser beam is emitted in a relatively strong and asymmetrical shape, it is possible to satisfactorily detect the vehicle that comes in from the left front side of the vehicle. Further, since the radiation intensity of the laser beam to the right side is relatively weak, a vehicle changing lanes from the lane adjacent to two lanes to the lane adjacent to one lane is not erroneously detected as an interrupt vehicle. For this reason, if the vehicle-mounted obstacle detection device is installed at a position other than the center of the front surface, unlike the conventional technology in which the detection limit distance of the laser beam is excessive or insufficient with respect to the lateral direction of the vehicle, Even if the device is attached, the detection limit distance does not become excessive or insufficient, so that an obstacle near both sides of the vehicle can be detected well. As a result, the safe inter-vehicle distance between vehicles can be kept good, and rear-end collisions and contact accidents can be reduced.

Although the present embodiment has been described above, the present invention is not limited to the above embodiment. For example, in the above-described embodiment, in order to detect obstacles in front of both sides of the vehicle, the emission part has a special structure so that an asymmetric laser beam can be emitted. As described above, the laser beam may be emitted at a wide angle with respect to the central direction, and the light receiving unit may be configured to have a special configuration so that an asymmetric laser beam can be received. That is, as shown in FIG. 5, the light receivers 50a, 50b, 50c, and the light receiving lens 51a,
The laser beam may be received by the light receiving unit 50 including 51b and 51c.

More specifically, the light receiver 50b is installed perpendicular to the traveling direction R, and a light receiving lens 51b is provided in the middle of the reflected light 5b entering the light receiver 50b. The light receiving lens 51b is composed of a convex lens. Further, the light receiving sensitivity of the light receiver 50b is set higher than that of the light receivers 50a and 50c, and has an acute angle and a symmetrical directivity.

The light receiver 50a has an angle φ with respect to the traveling direction R.
A light receiving lens 51a is provided in the middle of a portion where the reflected light 5a is incident on the light receiver 50a. The light receiving lens 51a is composed of, for example, two lenses, and is provided as a convex lens and a concave lens from the side closer to the light receiver 50a. The light receiving sensitivity of the light receiver 50a is set lower than that of the light receiver 50b and higher than that of the light receiver 50c.

The light receiver 50c is installed on the opposite side of the light receiver 50a with respect to the traveling direction R by an angle δ, and the reflected light 5c
A light receiving lens 51c is provided in the middle of the light incident on the light receiver 50c. The light receiving lens 51c is composed of, for example, two lenses, and a convex lens and a concave lens are provided in this order from the side closer to the light receiver 50c. The light receiving sensitivity of the light receiver 50c is the same as that of the light receivers 50a and 50b.
Is set lower than.

The light receiver 50b functions as a first receiver, and the light receivers 50a and 50c function as a second receiver. In this configuration, the light receiver 50b has an acute angle and symmetrical directivity, and the light receiving sensitivity is set to be higher than that of the other light receivers. Therefore, the reflected light from an obstacle located in the distance in front of the front of the vehicle is distant. 5b can be received. In addition, the light receiver 50a is
Since the light receiving sensitivity is set lower than that of the light receiver 50b and higher than that of the light receiver 50c, an obstacle nearer to the light receiver 50b with respect to the traveling direction R, and an angle from the center of the vehicle than the light receiver 50c. The reflected light 5b from an obstacle located at a distance in the φ direction is received. Further, since the light receiver 50c is set to have a light receiving sensitivity lower than that of the light receivers 50a and 50b, an obstacle nearer to the light receiver 50b in the traveling direction R and the center of the vehicle than the light receiver 50a. The reflected light 5c from the obstacle in the vicinity of the angle δ direction is received. Therefore, since the light receiver 50b can receive the reflected light from the obstacle far away from the front of the vehicle, the obstacle far away from the front can be detected. In addition, the light receiver 50a,
Since the reflected light from the obstacle within a substantially equal distance from the center of the vehicle can be received by the 50c, the obstacles on both sides of the vehicle can be reliably detected even in this configuration.

In addition, various design changes can be made without changing the gist of the present invention.

[0036]

As described above, according to the on-vehicle obstacle detecting device of the first aspect, even if the emitting means is provided on the front side of the vehicle from the second emitting portion, the horizontal direction from the center of the vehicle is obtained. An asymmetric electromagnetic wave is emitted so that the detection limit distances in the directions can be equalized. Therefore, even if the emission means is provided on the side of the front surface of the vehicle, it is possible to reliably detect an obstacle near both sides of the vehicle. For this reason, unlike the prior art in which an obstacle near both sides of the vehicle cannot be reliably detected unless the device is attached to the center of the front surface, the degree of freedom in the attachment position increases. Therefore, this device can be installed in any vehicle including vehicles that cannot be installed in the center of the front of the vehicle for some reason, so that a safe inter-vehicle distance can be maintained between vehicles and reduction of rear-end collisions and contact accidents. Can be planned.

Further, unlike the prior art in which a laser beam is emitted by using three light sources, the present invention uses only two emitting portions for emitting an electromagnetic wave. Therefore, the structure of the apparatus main body can be simplified and the cost can be reduced. Further, according to the on-vehicle obstacle detection device of the second aspect, even if the second receiving unit is provided on the front side of the vehicle, the second receiving unit is located within the same distance from the lateral center of the vehicle. Since the sensitivity is set so that the reflected wave from the object can be received, it is possible to reliably detect the obstacle near both sides of the vehicle. Therefore, since the degree of freedom in the mounting position is increased, the present device can be mounted in any vehicle. Therefore, it is possible to maintain a safe inter-vehicle distance between vehicles and reduce rear-end collisions and contact accidents.

[Brief description of drawings]

FIG. 1 is a diagram showing a specific arrangement example of an optical system.

FIG. 2 is a schematic view showing a simplified configuration of a vehicle-mounted obstacle detection device according to an embodiment of the present invention.

FIG. 3 is a diagram for explaining a specific example of obstacle detection in the vehicle obstacle detection device.

FIG. 4 is a diagram for explaining a specific example of obstacle detection in the vehicle obstacle detection device.

FIG. 5 is a diagram showing a modified example of the vehicle obstacle detection device.

FIG. 6 is a diagram for explaining the operation of the vehicle-mounted obstacle detection device according to the first embodiment.

FIG. 7 is a diagram for explaining the operation of the vehicle-mounted obstacle detection device according to the second aspect of the invention.

FIG. 8 is a diagram showing an example of emission of a conventional laser beam.

FIG. 9 is a diagram showing the directivity of the laser beam.

FIG. 10 is a diagram for explaining the drawbacks of the above conventional technique.

[Explanation of symbols]

 1 Vehicle Obstacle Detecting Device 2, 15, 16 Laser Beam 3, 3a, 3b Emitting Section 6 Light Receiving Section 7 Signal Processing Section 9a, 9b Light Source 10a, 10b Lens 11a, 11b, 50a, 50b, 50c Optical Receiver 12a, 12b , 51a, 51b, 51c Light receiving lens

Claims (2)

[Claims] 1. An emission means that is mounted on a vehicle and that emits an electromagnetic wave, and a reception means that receives a reflected wave of the electromagnetic wave from the emission means and detects an obstacle based on the received reflected wave. In the on-vehicle obstacle detection device having, the emitting means has a first emitting portion that emits an electromagnetic wave having a relatively strong intensity with an acute angle and a symmetrical directivity, and an obtuse angle and an asymmetrical orientation. And a second emission part that emits an electromagnetic wave having a relatively weak intensity. 2. An emission means which is mounted on a vehicle and is used to emit an electromagnetic wave, and a reception means which receives a reflected wave of the electromagnetic wave from the emission means and detects an obstacle based on the received reflected wave. In the on-vehicle obstacle detection device having, the receiving means has an acute angle and a symmetrical directivity, and a first receiving portion having a relatively high reception sensitivity and an obtuse angle and an asymmetric directivity. However, the vehicle-mounted obstacle detection device is characterized in that it includes a second receiver having a relatively low reception sensitivity.