JPH05205199A - Obstacle detection device for vehicle - Google Patents

Abstract

PURPOSE:To detect obstacles in both a short-distance area and a long-distance area by using only one light emission source by varying the spread angle of scanning. CONSTITUTION:This obstacle detection device is equipped with a light emission device 13 which is fitted above bumper 12 of a vehicle and emits beam light 14 forward. The light emission device 13 has constant width (t) in its width direction and emits the fan-shaped beam light 14 having a constant spread angle a in the perpendicular direction. This beam light 14 is emitted divisionally in two stages to form the obstacle detection area consisting of the fan-shaped short-distance detection area 15A and long-distance detection area 15B. The short-distance detection area 15A is formed by emitting the beam light 14 from the light emission device 13 at a spread angle deltaA up to a distance LA before the vehicle 11 and the long-distance detection area 15B is formed by emitting the beam light 14 at a spread angle deltaB up to a distance LB in front of the vehicle 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an obstacle detection device for a vehicle, which detects an obstacle ahead in the traveling direction while the vehicle is traveling.

[0002]

2. Description of the Related Art Generally, an obstacle detection device for a vehicle that detects an obstacle ahead of the vehicle in a traveling direction is a fan-shaped region having a predetermined divergence angle of a light beam emitted from a light source attached to the vehicle. The presence of the obstacle is detected by detecting the light beam that is emitted to the laser beam and reflected back to the obstacle.

In such an obstacle detecting device, the variable divergence angle of the light beam is disclosed, for example, in Japanese Utility Model Laid-Open No. 3-14477. According to the obstacle detection device disclosed in the publication, the divergence angle of the beam light is reduced when the vehicle is traveling at high speed, the beam light is made to reach far, the detection performance is improved in a narrow range far away, and low speed traveling is performed. At times, the divergence angle of the beam light is increased to irradiate the beam light near the front of the vehicle to improve the detection performance in a wide range near the vehicle.

The obstacle detection device disclosed in the above publication is 1
Since the light source is used to detect the obstacle, the beam light can be applied only to either the distant or the near. On the other hand, the automotive radar disclosed in Japanese Examined Patent Publication (Kokoku) No. 3-15713 uses two light emission sources (or radars) to detect obstacles in both distant and near regions. There is. That is, a radar having a narrow beam width is used for detecting an obstacle in the distance, and a radar having a wide beam width is used for detecting an obstacle in the near distance.

[0005]

An object of the present invention is to reduce the cost and save the space in an obstacle detecting device using only one light emitting source, such as the obstacle detecting device disclosed in Japanese Utility Model Laid-Open No. 3-14477. However, when the divergence angle of the beam light is reduced to detect an obstacle in the distance, the detection region in the near area becomes small, and sufficient obstacle detection cannot be expected especially when turning.

On the other hand, as in the device disclosed in Japanese Patent Publication No. 3-15713, if two light emitting sources are used, both far and near detection areas can be secured. New problems arise such as the need to secure space and the complexity of controlling two light sources. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an obstacle detection device capable of forming an obstacle detection region at both a distant position and a near position by using one light emitting source. To aim.

[0007]

To achieve this object, an obstacle detecting device according to the present invention is an obstacle detecting device for detecting an obstacle located in a predetermined region ahead of a vehicle in the traveling direction. The obstacle detection device is capable of simultaneously detecting obstacles in both a long-distance region and a short-distance region in front of the vehicle, and the divergence angle from the vehicle is different between the long-distance region and the short-distance region, and at least the The divergence angle from the vehicle for the short range can be changed,
Under a predetermined condition, the spread angle from the vehicle with respect to the short-distance area is enlarged.

Further, the obstacle detecting device according to the present invention is an obstacle detecting device for detecting an obstacle located in a predetermined region in front of the vehicle in the traveling direction, wherein the obstacle detecting device is in front of the vehicle. It is possible to simultaneously detect obstacles in both the long-distance area and the short-distance area, and the divergence angle from the vehicle with respect to the long-distance area and the short-distance area can be respectively changed. An area where the outer edge of the area and the outer edge of the long-distance area are connected is defined as an obstacle detection area.

In a preferred embodiment of the present invention, the divergence angle from the vehicle with respect to the short-distance area is increased when the visibility is reduced. For example, the time of wiper operation or headlight irradiation is determined to be when the visibility is reduced. In still another preferred embodiment of the present invention, the divergence angle from the vehicle with respect to the short-distance area is increased when the behavior of the vehicle is unstable or when there is an input to the winker.

In still another preferred embodiment of the present invention, when the vehicle turns, the obstacle detection area is directed in the turning direction, and the spread angle from the vehicle with respect to the short-distance area is opposite to the turning direction of the vehicle. Expand to.
In still another preferred embodiment of the present invention, the divergence angle from the vehicle with respect to the short-distance region is increased according to the vehicle speed.

[0011]

The obstacle detecting device according to the present invention detects obstacles not only in the long-distance area but also in the short-distance area at the same time, and the divergence angle from the vehicle in both areas can be changed. As compared with the case where the obstacle is detected only in the long-distance area, the area of the blind spot near the front of the vehicle can be reduced.

Further, during turning, an obstacle is detected in a region connecting the outer end of the short distance region and the outer end of the long distance region. As a result, the obstacle detection time can be shortened as compared with the case where an obstacle detection area having a complicated shape is set in accordance with the shape of the road, and further, in the middle of the short distance area and the long distance area. Even in the area, the obstacle can be detected more reliably.

Further, according to the embodiment of the present invention, it is determined that the field of view is deteriorated at the time of operating the wiper or at the time of illuminating the headlight, and the spread angle from the vehicle with respect to the short-distance region is enlarged. It is necessary to pay particular attention to obstacles in the short-distance region when the visibility is reduced. However, according to this embodiment, since the obstacles are intensively detected in the region closer to the front of the vehicle, the blind spot region in the short-distance region is particularly important. Can be reduced.

Similarly, even when the behavior of the vehicle is unstable, it is determined that the psychological state of the driver is unstable, and the spread angle for the short-distance area is expanded. As a result, it becomes possible to detect an obstacle in a short-distance region that the driver missed, and it is possible to achieve safe driving of the vehicle. Further, when there is an input to the winker, the spread angle for the short-distance area is similarly expanded. If there is an input to the turn signal, it can be predicted that the vehicle turns. When the vehicle turns, the visibility in the front tends to be deteriorated. Therefore, it is possible to more reliably confirm the safety in front of the vehicle by increasing the spread angle with respect to the short-distance area.

Also, when the vehicle is turning, the driver's attention tends to be neglected particularly in the area opposite to the turning direction. Therefore, the spread angle with respect to the short-distance area is expanded in the direction opposite to the turning direction. As a result, it becomes possible to assist the driver in noticing the obstacle detection.

[0016]

FIG. 1 shows an embodiment of an obstacle detection device for a vehicle according to the present invention. The obstacle detection device 10 includes a light emitting device 13 that is mounted above a bumper 12 of a vehicle 11 and emits a light beam forward. The light emitting device 13 emits a fan-shaped light beam 14 having a constant width t in the vehicle width direction and a constant spread angle α in the vertical direction.

The beam light 14 is irradiated in two stages to form an obstacle detection region 15 composed of a fan-shaped short-distance detection region 15A and a long-distance detection region 15B. Figure 2
As shown in FIG. 6, the short-distance detection area 15A is formed by irradiating the light beam 13 from the light emitting device 13 at a divergence angle δ _A to a distance L _A in front of the vehicle 11, and the long-distance detection area 15B emits light. From device 13 the spread angle δ _B (δ _B
It is formed by irradiating the light beam 14 to the distance L _B (L _B > L _A ) in front of the vehicle 11 at an angle of <δ _A ).

Here, an arbitrary angle from the traveling direction Y of the vehicle 11 is θ (the sign of the angle θ is positive when rotating clockwise from the Y axis and negative when rotating counterclockwise). In other words, the angle θ for scanning the light beam 14 and the reaching distance L of the light beam 14 are shown as follows. For -δ _A / 2 ≤ θ <-δ _B / 2 For L = L _A -δ _B / 2 ≤ θ ≤ δ _B / 2 For L = L _B δ _B / 2 <θ ≤ δ _A / 2 L = L _A Of these, the beam light 14 in the long-distance detection area 15B
The maximum reachable distance L _B is set as the maximum irradiation distance of the light emitting device 13. Further, the maximum reachable distance L _A of the light beam 14 in the short-distance detection area 15A is set equal to the distance required to stop after the traveling vehicle 11 finds an obstacle. That is, the maximum reachable distance L _A is the maximum braking distance Lx
Is set equal to and is given by

[0019] ^{_{L A = Lx = v 2 /}} 2μg ··· (1) where, v: vehicle speed mu: road surface friction coefficient g: acceleration of gravity.

The divergence angle δ _A is calculated by using a general lane width b (b
Is almost 3.5 m), and is given by the following equation. δ _A = b / L _A (rad) (2) i.e., it determined to be able to detect a single lane width of a maximum detection distance Lx forward.

Further, the spread angle δ _B is set to δ _B = δ _A / 2 (3). The method of setting the maximum reachable distances L _A and L _B and the spread angles δ _A and δ _B is an example, and other setting methods can be adopted.

FIG. 3 shows the structure of the obstacle detecting device 10.
The obstacle detection device 10 has, in addition to the above-described light emitting device 13, a light receiving device 16 that receives reflected light from the light emitting device 13. The light emitting device 13 and the light receiving device 16 are connected to a controller 17 that controls them. The controller 17 is connected to a sensor 18 that detects a steering angle θ of the vehicle 11, a vehicle speed v, and other traveling parameters.
Signals such as the steering angle of the vehicle 11 and the vehicle speed are received from 8.

The controller 17 has a microprocessor and plays a predetermined role by executing a predetermined program. The controller 17 receives a signal from the sensor 18 and calculates the traveling direction of the vehicle, and the calculator. 19
Signal from the detection area changing unit 20 that changes the direction and the spread angle δ of the obstacle detection area 15 according to the traveling state of the vehicle 11, and the signal from the detection area changing unit 20 is input to the obstacle. The obstacle detection unit 23 that determines the presence of the vehicle and generates a signal to the automatic braking device 21 or the alarm device 22 based on the determination result.

The light emitting device 13 is composed of a scan type laser for scanning the fan-shaped light beam 14,
The light receiving device 16 is composed of a scan type sensor that receives the reflected light from the obstacle of the light beam emitted by the light emitting device 13. The obstacle detection unit 23 uses the light emitting device 13
The position of the obstacle is detected based on the propagation time of light from the light receiving device 16 to the light receiving device 16 and the direction of the reflected light.

The calculation unit 19 obtains the vehicle body side slip angle β and the vehicle turning radius R of the vehicle 11 based on the signal from the sensor 18. The vehicle side slip angle β and the vehicle turning radius R are calculated according to the following equations. beta = [- 1+ (m / 2s) ( s f / s r K r) v 2 ] _{(s r / s) (θ} / N) / (1 + Av 2) ····· (4) R = (1 + Av ² ) s (N / θ) (5) A: Stability factor [s ² /
m ² ] s: Wheel base [m] N: Steering gear ratio m: Vehicle mass [kg] s _f : Distance from vehicle center of gravity to front wheels [m] s _r : Distance from vehicle center of gravity to rear wheels [m] K _r : Cornering power of rear tire [N / ra
d] K _f : Cornering power of front tire [N / ra
d] The stability factor A is expressed by the following equation.

A = (m / 2s ² ) (s _r K _r −s _f K _f ) / K _f K _r The relationship between s, s _f , and s _r is expressed by the following equation. s = s _f + s _r An example of detecting an obstacle using the obstacle detection device 10 having the above configuration will be described below.

FIG. 4 shows the short-distance detection area 15A according to the vehicle speed.
3 is an example of control for expanding the spread angle Δ _A of the. First, the controller 17 inputs signals indicating the traveling state of the vehicle 11 such as the steering angle θ and the vehicle speed v from the various sensors 18 (step S1). Next, the controller 17 calculates the vehicle body side slip angle β and the vehicle turning radius R from the above equations (4) and (5) based on these signals (step S2).

Then, the maximum detection distance L _A and the spread angle δ _A for the short-distance detection area 15A are calculated based on the equations (1) and (2) (step S3), and further the distance is calculated based on the equation (3). The divergence angle δ _B with respect to the distance detection area 15B is obtained, and the maximum detection distance L _{B with} respect to the long distance detection area 15B is obtained.
Is set equal to the maximum irradiation distance of the light emitting device 13 (step S4).

In this way, the maximum detection distances L _A , L _B
When the obstacle detection area 15 is set from the divergence angles δ _A and δ _B , the controller 17 controls the obstacle detection area 15
The direction φ _i of the obstacle existing in the vehicle and the distance n _i to the obstacle are detected (step S5), and the direction φ of the obstacle closest to the vehicle 11 among these obstacles φ,
And the distance n are obtained (step S6).

Next, the controller 17 executes a danger judging routine to judge the degree of danger of the obstacle (step S7). FIG. 5 shows a flowchart of the risk judgment routine. The controller 17 first determines the relative speed V between the vehicle 11 and the obstacle based on the change in the distance n _j of the obstacle.
_{Find j} (step S1).

Next, thresholds l ₁ , l ₂ and l for judging the degree of danger from road friction coefficient μ, relative speed V _j and vehicle speed v.
₃ (l ₁ <l ₂ <l ₃ ) is set (step S2). next,
The controller 17 determines whether or not the relative speed V _j is positive (step S3). If the relative speed V _j is positive, the vehicle 11 is approaching the obstacle, and if the relative speed V _j is negative, the vehicle 11 is moving away from the obstacle.

If this determination is YES, it is further determined whether or not the distance n to the obstacle is smaller than the threshold value l ₂ (step S4). This determination result is NO, that is,
If the distance n to the obstacle is greater than the threshold l ₂ ,
The controller 17 determines that the vehicle 11 is in the safe area, and sets the flag J for determining the degree of risk to 0 (step S5). The flag J = 0 indicates that the vehicle 11 is in a safe area, that is, an area having no risk.

If the determination in step S4 is YES, that is, if the distance n to the obstacle is smaller than the threshold l ₂ , the vehicle 11 is relatively close to the obstacle, and
Controller 1 as it is approaching an obstacle
7 sets the flag J to 1 (step S6). The flag J = 1 indicates that the vehicle 11 is in the warning area, that is, the danger area is not as high as the danger area, but the danger degree is higher than the safety area and the warning is issued in order to call attention.

Further, the controller 17 determines whether or not the distance n to the obstacle is smaller than the threshold value l ₁ (step S7). If the determination result is NO, that is, if the distance n to the obstacle is larger than the threshold l ₁ , the vehicle 11 is approaching the obstacle but at least the distance l ₁
No further action is taken as they are far apart and have already been shown to be in the alarm zone.

If the determination result in step S7 is YES, that is, if the distance n to the obstacle is smaller than the threshold value l ₁ , the vehicle 11 is extremely close to the obstacle and the obstacle is present. Since it is a case of approaching an object, the controller 17 sets the flag J to 2 (step S8). The flag J = 2 indicates that the vehicle 11 is in a dangerous area, that is, an area where the degree of danger is extremely high and an operation such as automatic braking is required.

Further, the determination result in step S3 is N
In the case of O, that is, when the relative velocity V _j is negative, the controller 17 further determines whether or not the distance n to the obstacle is smaller than the threshold l ₃ (step S).
9). When the result of this determination is NO, the controller 17 determines that the vehicle 11 is in the safe area and sets the flag J to 0 (step S10).

If the result of the determination is YES, it means that the obstacle is moving away, but in order to call attention to the driver for the time being, it is determined to be an alarm area and the flag J is set to 1 (step S11). ). The controller 17 determines the value of the flag J and outputs a control signal according to the value. For example, when J = 2 (danger area), the automatic braking device 21 is activated, and when J = 1 (warning area), the alarm device 22.
Operate. When J = 0 (safety area), no control signal is output to any device.

Thus, in this embodiment, the vehicle speed v
The maximum detection distance L _A for the short-range detection area 15A
To set. If the vehicle speed v is set, the long-distance detection area 15B is detected.
When the maximum detection distance L _B is set to, the maximum detection distance L _B becomes short at low speed, and an alarm or other control is performed when an object with a high relative speed (for example, an oncoming vehicle approaching at high speed) is about to collide. It may not be in time.
Further, if the maximum detection distance L _A is kept constant irrespective of the vehicle speed v, the obstacle detection area at a short distance becomes narrow. On the other hand, as in the present embodiment, the maximum irradiation distance of the light emitting device 13 is set to the maximum detection distance L _B with respect to the long-distance detection area 15B,
By setting the distance obtained from the vehicle speed v equal to the maximum detection distance L _A for the short-distance detection area 15A, it is possible to secure the obstacle detection area in the long distance, and it is possible to expand the obstacle detection area in the short distance. Become.

FIG. 6 shows a second embodiment of the obstacle detecting device 10 according to the present invention. In the present embodiment, the divergence angle δ _A with respect to the short-distance detection area 15A is increased when the visibility is reduced or the driver is in a panic state.
Whether or not the visibility is reduced is determined as the case where the wiper is operated, the headlight is illuminated, or the input is made on the turn signal as the case where the visibility is reduced. Also,
Whether or not the driver is in a panic state is determined to be in a panic state if the change rate of the steering angle θ or the estimated value Ge of the lateral gravity acceleration is equal to or larger than a predetermined value.

First, the controller 17 uses the various sensors 1
A signal indicating the traveling state of the vehicle 11 such as the steering angle θ and the vehicle speed v is input from 8 (step S1). The controller 17 then based on these signals, equation (4) above,
The vehicle side slip angle β and the vehicle turning radius R are calculated from (5) (step S2). Next, the maximum detection distance L _B for the long-distance detection area 15B is set equal to the maximum irradiation distance of the light emitting device 13, and the spread angle δ _B for the long-distance detection area 15B is set by the following equation (step S3).

Δ _B = b / L _B Here, b is the value of the road width on which the vehicle 11 is actually traveling, but the value of the most road width is adopted, and b = 3.5 in advance.
[M]. Regarding the road width b, the vehicle 1
It is also possible to mount a camera in No. 1 and obtain the actual road width b by using the image recognition method by the camera.

The flag S for judging the degree of risk is set to zero (step S4), and then the short distance detection area 15 is set.
The maximum detection distance L _A for _A is set to zero (step S5). First, the controller 17 determines whether the wiper is operating (step S6).

If the result of this determination is NO, that is, if the wiper is not operating, it is further determined whether or not the headlight is in the ON state (step S7).
If the result of this determination is NO, that is, if the wiper is not operating and the headlights are not illuminated, it is further determined whether or not the fog lamp is in the ON state (step S8).

If any of the wiper, headlight, or fog lamp is operating or illuminated, the flag S is set to S = 1 (step S9). If none of them are active, flag S remains zero. Next, the controller 17 determines whether the rate of change of the steering angle θ is larger than the predetermined value A (step S1).
0). Although any value can be used as the predetermined value A, for example, A = 500 degrees / second is used.

If the result of this determination is NO, it is further determined whether or not the estimated lateral acceleration value G _e is greater than a predetermined value B (step S11). The predetermined value B can be any value, for example, B = 15 m /
Set to ² seconds. The estimated value G _e can be obtained, for example, from the following estimation formula. G _e = v ² θ / (1 + Av ² ) sN Note that the lateral acceleration can also be obtained as an actual value using a sensor.

These two judgments (steps S10 and S11)
When any one of the determination results in is YES, 4 is added to the flag S. If all the determination results are NO, the flag S does not change. These two determinations (steps S10 and S11) are for determining the behavior state of the vehicle 11. If any of the determination results is YES, the behavior of the vehicle is unstable, and it is estimated that the driver is psychologically panicked for some reason.

Next, the controller 17 determines whether or not there is an input to the winker. When the turn signal is input, 2 is added to the flag S. When there is no input, the value of flag S does not change. After that, the controller 17 determines the value of the flag S and determines the spread angle δ _A for the short-distance detection area 15A according to the value (step S15).
-19), the maximum detection distance L _A for the short-distance detection area 15A is determined based on the value of the spread angle δ _A (step S20).

First, the controller 17 determines whether or not the flag S is smaller than 1, that is, S = 0 (step S15). If the determination result is YES, that is,
When the flag S = 0, the spread angle δ _A for the short distance detection area 15A is set to δ ₀ . Judgment result is NO
In the case of, that is, when the flag S ≧ 1, it is further determined whether or not the flag S <4 (step S17).

When this determination result is YES, that is,
When the flag S = 1 to 3, the spread angle δ _{A is set} to δ ₁
(Step S18). When the determination result is NO, that is, when the flag S ≧ 4, the spread angle δ _A
Is set to δ ₂ (step S19). δ ₀ , δ ₁ , δ
The relationship between the _two should be δ ₀ <δ ₁ <δ ₂ . That is, the larger the value of the flag S, in other words, the larger the danger level is, the larger the spread angle δ _A is set. An example of setting δ ₀ , δ ₁ , and δ ₂ is given below.

Δ ₀ = 1.5 × δ _B δ ₁ = 2.0 × δ _B δ ₂ = 3.0 × δ _B Then, based on the spread angle δ _A set in this way, the short range detection area 15A The maximum detection distance L _A for is calculated (step S20).

L _A = b / δ _{A In} this way, the maximum detection distance L _A , the divergence angle δ _A for the short distance detection region 15A and the maximum detection distance L _B , the divergence angle δ _B for the long distance detection region 15B are obtained. The obstacle detection area 15 is formed. Subsequent steps S21-
23 is the same as steps S5 to S7 in the first embodiment.

In the second embodiment, as described above, the divergence angle δ _B with respect to the short-distance detection area 15A is increased when the visibility is reduced or the driver panics, so that the blind spot in the short-distance area in front of the vehicle is reduced. Therefore, driving safety can be improved. 7 and 8 show a third embodiment. In the present embodiment, when the vehicle is traveling on a curve, the obstacle detection area 15 is shifted in the turning direction of the vehicle and the short-distance detection area 15 is also provided.
The divergence angle δ _A with respect to A is enlarged in the direction opposite to the turning direction of the vehicle.

First, the controller 17 uses the various sensors 1
Signals indicating the traveling state of the vehicle 11 such as the steering angle θ and the vehicle speed v are input from 8 (step S1), and based on these signals, the vehicle body side slip angle β, the vehicle turning angle from the above equations (4) and (5). The radius R is calculated (step S2). Next, the controller 17 calculates the maximum reachable distance L _X of the light beam 14 using the vehicle speed v based on the following equation (step S
3).

L _X = v / 2 μg where μ is the road friction coefficient and g is the gravitational acceleration. Next, the controller 17 determines that the vehicle turning radius R is a predetermined value 4R.
_It is determined whether it is smaller than ₀ (step S4). How to obtain the reference value R ₀ will be described later. This judgment result is N
When it is O, that is, when R ≧ 4R ₀ , it can be estimated that the radius of the curve on which the vehicle 11 is traveling is sufficiently large. Therefore, if only the short-distance detection area 15A is formed as the obstacle detection area 15, the obstacle can be sufficiently detected. Therefore, only the short-distance detection area 15A is formed and the long-distance detection area 15B is not formed. The spread angle δ _{A of} the short distance detection area 15A and the angle ζ _A formed by the center line f of the short distance detection area 15A and the actual traveling direction Y of the vehicle 11 are set according to the following equations (step S5).

Δ _A = b / L _X ζ _A = L _X / 2R-β where b is the road width and β is the vehicle body side slip angle. In this way, when δ _A and ζ _A are obtained, the obstacle detection region 15 having only the short-distance detection region 15A as shown in the schematic diagram H is formed.

If the determination as to whether or not the turning radius R of the vehicle 11 is smaller than 4R ₀ (step S4) is YES, the spread angle δ _A for the short-distance detection area 15A is set equal to the angle δ ₃ (step S4). S6). The angle δ ₃ is obtained as follows. As shown in FIG. 9, the vehicle 11 has a velocity vector v directed in a tangential direction of the turning radius R, but since the vehicle 11 actually has a side slip angle β, the actual traveling direction of the vehicle 11 is Is a direction Y deviated from the velocity vector v by an angle β.

The angle δ ₃ is the shoulder 25 on the inside of the turning direction of the road.
Is set equal to the angle formed by the beam light 26 in contact with the beam light traveling in the direction of the velocity vector v. The obstacle detection area 15 defined by the angle δ ₃ is selected as the minimum necessary obstacle detection area in the traveling direction of the vehicle 11. Next, an angle for shifting the obstacle detection area 15 in the turning direction, that is, an angle ζ _A formed by the center line f of the short distance detection area 15A and the traveling direction Y of the vehicle 11 is set according to the following equation (step S7).

Ζ _A = (δ _A / 2) (Absolute value of θ / θ) −β Furthermore, the maximum detection distance L for the short-distance detection area 15 A
_A is set according to the following equation (step S8). L _A = b / _{δ A} in this manner, [delta] _A, by zeta _A, L _A is set, short range detection area 15A, as shown in the schematic J
Is formed. Thereafter, the long distance detection area 15B is set according to the turning radius R (steps S9 to 13), and the short distance detection area 15A and the long distance detection area 15B are combined to form the obstacle detection area 15 ( FIG. 8 (A), (B)).

First, the controller 17 determines whether the turning radius R is smaller than the reference value R ₀ (step S).
9). When this determination result is NO, that is, R ₀
When ≦ R <4R ₀ , the long distance detection area 15B is set as follows (step S10). δ _B = b / L _X ζ _B = L _X / 2R−β δ _B is the spread angle of the long-distance detection area 15B, and ζ _B is the center line h of the long-distance detection area 15B as the traveling direction Y of the vehicle 11. Angle. This spread angle δ _B and tilt angle ζ
_The long-distance detection region 15B formed by B has a shape as shown in the schematic view L, and the short-distance detection region 15A (schematic J) formed by steps S6 to 8 and the long-distance detection region 15B are combined. The obstacle detection area 15 is shown in FIG.
The shape is as shown in FIG.

When it is determined whether the turning radius R is smaller than the reference value R ₀ (step S9) is YES, the controller 17 determines the maximum reachable distance L _X of the light beam 14 from the value obtained in step S3. The value is changed to the value obtained by the following equation (step S11). L _X = 2 [b (absolute value of 2R−b / 2) / 2] ^1/2 Next, the divergence angle δ _B and the angle ζ _B for the long-distance detection area 15B are obtained based on the following equations (step S1
2).

Δ _B = b / 2L _X ζ _B = Φ ₀ − (δ _B / 2) (Absolute value of θ / θ) The long-distance detection area 15B formed by the two angles δ _B and ζ _B is a schematic diagram. The shape is as shown in K. Step S
The obstacle detection region 15 obtained by combining the short-distance detection region 15A (schematic diagram J) formed by 6 to 8 and the long-distance detection region 15B has a shape as shown in FIG. 8 (A).

As described above, the shape of the obstacle detection area 15 is set according to the size of the turning radius R. The shape shown in the schematic diagram H has a gentle curve (4R ₀ ≦ R), and the shape shown in FIG. 8B has a slightly steep curve (R
₀ ≦ R <4R ₀ ), the shape shown in FIG. 8A is the shape of the obstacle detection region 15 when the curve is steep (R <R ₀ ).

When the vehicle 11 is traveling on a gentle curve (4R ₀ ≤R) (the case shown in the schematic diagram H), L _X <L
_b (L _b is the contact point B from the vehicle 11 to the inside of the road of the light beam)
To the contact point B.
However, the obstacle is detected within a very short distance in front of the vehicle 11. When the vehicle 11 is traveling on a slightly steep curve (R ₀ ≦ R <4R ₀ ) (the case shown in FIG. 8B), L _b <L _X <L _a (L _a is the estimated trajectory of the vehicle 11 And the distance between the vehicle 11 and the intersection A between the beam light passing through the contact point B and the vehicle 11).
Has a two-step shape as shown in FIG. That is, the short-distance detection area 15A reaches the contact point B, and the long-distance detection area 15B reaches a point in front of the intersection A.

When the vehicle 11 is traveling on a sharp curve (R <R ₀ ) (the case shown in FIG. 8A), L _a <L _X , but the obstacle detection area 15 reaches the intersection A. Take That is, the short distance detection region 15A reaches the contact point B, and the long distance detection region 15B reaches the intersection point A. A method of calculating the reference value R ₀ described above will be described with reference to FIG. 9. Consider a case where the vehicle 11 is turning with a turning radius R. Although the driving force of the vehicle 11 is directed in the velocity vector v direction,
Since a side slip angle β occurs in the vehicle, the actual traveling direction of the vehicle 11 is the Y direction. A tangent line 26 is drawn from the vehicle 11 to the end portion 25 on the inside of the turning direction of the road, and an intersection point with the end portion 25 is B, and an intersection point between the tangent line 26 and the estimated trajectory of the vehicle 11 (a circle having a radius R) is A. If the distance from the vehicle 11 to the contact point B is x, the distance from the vehicle 11 to the intersection A is 2x.
Here, x is represented by the following equation.

X = [R ² − (R−b / 2) ² ] ^1/2 = [(2R−b / 2) b / 2] ^1/2 where the maximum reachable distance L _{x of the} light beam 14 is L _x > 2x
Considering the case, since the point of the maximum reachable distance L _x from the vehicle 11 in the traveling direction of the vehicle 11 is located farther than the point A as viewed from the vehicle 11, it is not within the field of view of the vehicle 11. .. If the turning radius R at this time is R ₀ , then L _X = 2 [(2R ₀ −b / 2) b / 2] ^1/2 holds. When R ₀ is obtained from this equation, R ₀ = (L _X ² / 2b + b / 2) / 2.

If the angle from the actual traveling direction Y of the vehicle 11 to the tangent line 26 is Φ ₀ , then Φ ₀ = θ ₀ -β. Here, θ ₀ is an angle formed by the velocity vector v of the vehicle 11 and the tangent line 26, and this angle θ ₀ is the turning center O.
Is equal to the angle formed by the vehicle 11 and the contact point B. here,
θ ₀ is θ ₀ = sin ⁻¹ (x / R) ≈ [(2R−b / 2) b / 2] ^1/2 / R.

For example, if L _X = 100 m and b = 3.5 m, then R ₀ = 715 m Φ ₀ ≈4 ° -β, and if L _X = 50 m and b = 3.5 m, then R ₀ = 180 m Φ. ₀ = 8 ° −β.

R ₀ and Φ ₀ may be represented by the following simplified formula. R ₀ ≈L _X ² / 4b Φ ₀ = (bR) ^1/2 / R−β Focusing on the contact B, if L _X = x, then R ₀ ′ = (2L _X ² / b + b / 2) / 2≈L _X ² / b≈4R ₀ δ ₃ = b / x = b / [(2R−b / 2) b / 2] ^1/2 ≈ (b / R) ^1/2 .

A fourth embodiment is shown in FIGS. 10 and 11.
In the present embodiment, as shown in FIG. 10 (B), when the vehicle 11 turns, the obstacle detection area 15 including the short distance detection area 15A and the long distance detection area 15B is shifted in the turning direction of the vehicle 11. The area where the outer end of the short distance detection area 15A and the outer end of the long distance detection area 15B are connected to each other is set as the obstacle detection area 15.

First, the controller 17 uses the various sensors 1
Signals indicating the traveling state of the vehicle 11 such as the steering angle θ and the vehicle speed v are input from 8 (step S1), and based on these signals, the vehicle body side slip angle β, the vehicle turning angle from the above equations (4) and (5). The radius R is calculated (step S2). Then, for example, as in the case of the third embodiment described above, the spread angle δ _A for the short distance detection region 15A, the maximum detection distance L _A , the shift angle ζ _A, and the spread angle δ _B for the long distance detection region 15B, the maximum detection. The distance L _B and the shift angle ζ _B are calculated (step S3).

Further, each point of the two outer end portions 31 and 34 of the short distance detection area 15A and the two outer end portions 32 and 33 of the long distance detection area 15B is the actual traveling direction Y of the vehicle 11.
Angles Φ _{1 to} Φ ₄ are calculated based on the following equation (step S4). Φ ₁ = ζ _A −δ _A / 2 φ ₂ = ζ _B −δ _B / 2 φ ₃ = ζ _B + δ _B / 2 φ ₄ = ζ _A + δ _A / 2 Next, existing within the maximum irradiation range of the light emitting device 13. The direction Φ _J and the distance n _J of all obstacles to be detected are detected (step S
5).

Then, based on the following equation, the maximum detection distance L _X for detecting an obstacle is calculated with respect to the angle Φ formed by an arbitrary point in the obstacle detection area 15 with the actual traveling direction Y of the vehicle 11. (Step S6). Φ <= L _X If For [Phi ₄ of _{L X = 0 Φ 4 <Φ} <Φ 3 _{[(Φ 3 -Φ) L B +} (Φ-Φ 4) L A ] /
_{(Φ 3 -Φ 4) Φ 3} <Φ < If in the case of [Phi ₂ of _{L X = L B Φ 2 <} Φ <Φ 1 L X = _{[(Φ 1 -Φ) L B +} (Φ-Φ 2 ) L _A ] /
If (Φ ₁ −Φ ₂ ) Φ ₁ <Φ, then L _X = 0. Then, the distance n _J of each obstacle detected in step S5 is calculated from each maximum detection distance L _{X with} respect to the arbitrary angle Φ obtained in step S6. It is determined whether or not it is small, that is, whether or not each obstacle is located within the obstacle detection area (step S7).

Next, the obstacle closest to the vehicle 11 is selected from the obstacles for which the judgment result is YES, and the direction Φ and the distance n thereof are calculated (step S).
8). After that, a risk judgment routine is executed (step S9). In this way, by forming the obstacle detection area 15 into a pentagonal shape as shown in FIG. 10, the obstacle detection area is expanded by relatively simple calculation, and the obstacle is detected with higher accuracy. It will be possible.

In each of the above-described embodiments, the obstacle detection area 15 is divided into two steps, that is, the short distance detection area 15A and the long distance detection area 15B. It is also possible to form it in stages or more. However, if a large number of stages are set, the detection accuracy is improved, but it takes time to calculate the distance to the obstacle, and the reaction time until the obstacle is detected is delayed, so two stages are most preferable.

[0075]

As described above, according to the present invention, an obstacle can be detected in both the short distance area and the long distance area by using only a single light emitting source. Further, since the short-distance area is enlarged when the visibility is reduced or the vehicle is turning, it is possible to form the obstacle detection area according to the traveling condition of the vehicle.

[Brief description of drawings]

FIG. 1 is a perspective view conceptually showing an obstacle detection area of a vehicle.

FIG. 2 is a plan view of an obstacle detection area shown in FIG.

FIG. 3 is a conceptual diagram showing a schematic configuration of an obstacle detection device according to the present invention.

FIG. 4 is a flowchart of an example of control of the obstacle detection device according to the present invention.

FIG. 5 is a flowchart of a routine for determining a risk level.

FIG. 6 is a flowchart of an embodiment of control of the obstacle detection device according to the present invention.

FIG. 7 is a flowchart of another embodiment of control of the obstacle detection device according to the present invention.

FIG. 8A and FIG. 8B are plan views showing an example of an obstacle detection region enlarged when the vehicle turns.

FIG. 9 is an explanatory diagram showing a method of setting an obstacle detection area.

FIG. 10 is a plan view showing another example of the enlarged obstacle detection area.

FIG. 11 is a flowchart of control when forming the obstacle detection area shown in FIG.

[Explanation of symbols]

 11 Vehicle 13 Light-Emitting Device 14 Beam Light 15A Near-distance Detection Area 15B Long-distance Detection Area 15 Obstacle Detection Area 16 Light-Receiving Device 17 Controller 18 Sensor 19 Calculation Unit 20 Detection Area Change Unit 21 Automatic Braking Device 22 Alarm Device 23 Obstacle Detection Unit 25 Road inside edge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoru Matsuoka 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Motor Corporation

Claims (9)

[Claims] 1. An obstacle detection device for detecting an obstacle located in a predetermined region in front of the vehicle in the traveling direction, wherein the obstacle detection device is a long-distance region and a short-distance region in front of the vehicle. It is possible to simultaneously detect obstacles in both, and the divergence angle from the vehicle is different between the long-distance area and the short-distance area, and at least the divergence angle from the vehicle with respect to the short-distance area is changeable, and the predetermined condition is satisfied. Below, the obstacle detection device for a vehicle is characterized in that a spread angle from the vehicle with respect to the short-distance region is enlarged. 2. An obstacle detection device for detecting an obstacle located in a predetermined region in front of the vehicle in the traveling direction, wherein the obstacle detection device is a long-distance region and a short-distance region in front of the vehicle. It is possible to simultaneously detect obstacles in both, the divergence angle from the vehicle with respect to the long-distance area and the short-distance area can be changed, respectively, when the vehicle turns, the outer edge of the short-distance area and the long-distance area. An obstacle detection device for a vehicle, which detects an obstacle in a region connected to an outer end. 3. The obstacle detection device for a vehicle according to claim 1, wherein a divergence angle from the vehicle with respect to the short-distance area is increased when the visibility is reduced. 4. The obstacle detection device for a vehicle according to claim 3, wherein the time when the wiper is operated is determined to be when the visibility is reduced. 5. The obstacle detection device for a vehicle according to claim 3, wherein the time when the headlight is illuminated is determined to be when the visibility is reduced. 6. The obstacle detection device for a vehicle according to claim 1, wherein a divergence angle from the vehicle with respect to the short-distance area is increased when the behavior of the vehicle is unstable. 7. The obstacle detection device for a vehicle according to claim 1, wherein a spread angle from the vehicle with respect to the short-distance area is enlarged when an input is made to a winker. 8. When turning the vehicle, an obstacle detection area including the short-distance area and the long-distance area is directed in the turning direction, and the spread angle from the vehicle with respect to the short-distance area is defined as the turning direction of the vehicle. The vehicle obstacle detection device according to claim 1, wherein the obstacle detection device expands in the opposite direction. 9. The obstacle detection device for a vehicle according to claim 1, wherein a divergence angle from the vehicle with respect to the short-distance area is enlarged according to a vehicle speed.