JPH05205198A - Obstacle detection device for vehicle - Google Patents

Abstract

PURPOSE:To minimize the possibility of misdetection by employing none of obstacle detection data from an area wherein an obstacle need not be detected. CONSTITUTION:An ultrasonic sensor 27 sends out an ultrasonic wave to a guard rail 25 and the calculation part 19 of a controller 17 finds the distance between a vehicle 11 and the guard rail 25 from the time required by that the radio wave reflected by the guard rail 25 returns. When the vehicle 11 travels on a straight path 24, an obstacle positioned outside the guide rail need not be detected, so the controller 17 the controller 17 performs control so that the detection data from the area S1 positioned outside the guide rail 25 in an obstacle detection area 15 are not employed. Further, since an obstacle on the opposite lane need not be detected, the controller 17 performs control so that data from an area S2 positioned on the opposite lane are not employed. Consequently, the possibility of misdetection can be minimized.

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.

Further, Japanese Patent Application Laid-Open No. 2-287180 discloses a device for switching the emission direction of beam light according to the traveling direction of a vehicle when the vehicle turns.

[0005]

OBJECTS OF THE INVENTION In this type of obstacle detection device, it is essential to prevent erroneous detection of non-obstacles as obstacles. Points to people and bicycles that have jumped out on the road or those that have been struck). In particular, fixedly installed objects such as roadside guardrails and sign poles are likely to be the target of erroneous detection. Whenever a guardrail or sign pole is detected as an obstacle each time it is detected as an obstacle, the automatic braking device and automatic alarm device connected to the obstacle detection device will be activated, which may adversely affect the psychological state of the driver. ..

However, the obstacle detecting device disclosed in the above publication does not take any measures for preventing erroneous detection. The present invention has been made in view of this problem, and an object thereof is to provide an obstacle detection device that prevents erroneous detection of a non-obstacle such as a guardrail as an obstacle.

[0007]

In order 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 area ahead of a vehicle in the traveling direction. It is characterized in that the detection data of the obstacle located in the set area of the area is not adopted.

In a preferred embodiment of the present invention, the distance from the vehicle to the installation beside the road is detected, and the setting area is set according to the distance. In another preferred embodiment of the present invention, when the vehicle is traveling on a straight road, the area of the oncoming lane is set as the setting area. In a further preferred embodiment of the present invention, when the vehicle is traveling on a curved road, the region outside the curved road in the radial direction is set as the setting region.

[0009]

The obstacle detecting device according to the present invention detects all obstacles existing in a predetermined area in front of the vehicle.
Among them, the detection data obtained from the area where it is not necessary to detect the obstacle (for example, the area outside the guardrail or the outside of the curve) is not adopted, and the area excluding these unnecessary areas (that is, , Only the detection data of obstacles existing in the area on the road on which the vehicle is currently traveling) is used to determine the presence / absence of obstacles.

This makes it possible to prevent erroneous detection and detect only obstacles to be detected.

[0011]

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. An obstacle detection region 15 is formed by scanning the light beam 14 within a range of a predetermined spread angle δ.

Maximum reachable distance L of the light beam 14
x is set equal to the distance required for the moving vehicle 11 to stop after finding an obstacle. That is, the maximum distance Lx is given by the following equation. Lx = v ² / 2μg v: vehicle speed mu: road surface friction coefficient g: acceleration of gravity divergence angle [delta], the general lane width b (b is approximately 3.5m
There are many roads) and is given by the following equation.

Δ = b / Lx [rad] That is, it is determined that one lane width can be detected in front of the maximum detection distance Lx. FIG. 2 shows the configuration of the obstacle detection 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 controls the steering angle of the vehicle 11,
It is connected to each sensor 18 that detects the vehicle speed or the distance from the vehicle to the guardrail on the side of the road, and receives a signal according to the steering angle, the vehicle speed, the distance, etc. from this sensor 18.

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 a turning radius of the vehicle 11 and the like. The detection area changing unit 20 which receives the signal from the calculating unit 19 and changes the direction and the spread angle δ of the obstacle detecting area 15 according to the traveling state of the vehicle 11 and the signal from the detection area changing unit 20 are input. An obstacle detection unit 23 that determines the presence of an obstacle and generates a signal to the automatic braking device 21 or the alarm device 22 based on the determination result is provided.

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 from the propagation time of light from 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. β = (- 1+ (m / 2s) (s f / s r K r) v 2) (s r / s) (θ / N) / (1 + Av 2) ····· (1) R = (1 + Av ² ) s (N / θ) (2) 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.

A vehicle 1 having a vehicle width W, as shown in FIG.
1 is traveling on a straight road 24. On the side of the straight road 24, a guardrail 25 extends along the straight road 24,
A white line 26 as a center line is provided in the center of the straight road 24.
Is drawn. The vehicle 11 has an obstacle detection region 15 having a divergence angle δ formed in front of the traveling direction by a light emitting device 13 mounted in front of the vehicle 11.

An ultrasonic sensor 27 is attached to the side of the vehicle 11. Ultrasonic sensor 27 is guardrail 2
5, the calculation unit 19 of the controller 17 obtains the distance L ₁ between the vehicle 11 and the guardrail 25 from the time until the ultrasonic wave is reflected by the guardrail 25 and returns. In this way, when the vehicle 11 is traveling on the straight road 24, it is not necessary to detect an obstacle located outside the guardrail 25, and therefore the controller 17 causes the obstacle detection unit 23 to detect the obstacle. The detection data from the area S ₁ (hatched portion) located outside 25 is controlled not to be adopted.

That is, when the coordinates of an arbitrary point P inside the obstacle detection area 15 are represented by (r, θ) using polar coordinates with the light emitting device 13 as the origin, −r (sin θ) ≧ L ₁ + W / 2 (1) (where 0 <θ ≦ −δ / 2 negative sign indicates θ is the traveling direction Y of the vehicle 11)
The detection data from the point (r, θ) that satisfies the condition (showing that it is in the counterclockwise direction) is not adopted.

Further, since it is not necessary to detect the obstacle existing in the oncoming lane, the controller 17 of the obstacle detecting section 23 of the controller 17 is located in the oncoming lane in the obstacle detecting area S ₂ (hatched portion). It controls not to adopt the detection data from. That is, r (sin θ) ≧ b−L ₁ −W / 2 (2) (where 0 <θ ≦ δ / 2θ is clockwise when viewed from the traveling direction Y of the vehicle 11) is satisfied. The detection data from the point (r, θ) to be used is not adopted.

Here, b is the road width of the traveling lane in which the vehicle 11 is currently traveling, and the value of the road width b is preset to 3.5 m, which is the largest road width. Alternatively, as will be described later, it is also possible to measure the actual road width b using an image recognition means and use that value. In this embodiment, the ultrasonic sensor 27 is used to measure the distance L ₁ , but it is possible to measure the distance L ₁ and the road width b by using an image recognition method instead of the ultrasonic sensor 27. Is.

An example thereof is shown in FIGS. 4 and 5. As shown in FIG. 4, the vehicle 11 has a camera 28 mounted on a center line that divides the vehicle width into two. This camera 28 is camera 2
The range of the width Q at the position of the distance X ahead of 8 is displayed on the screen 2
Copy to 9. FIG. 5 shows a method of obtaining the distance L ₁ and the road width b by image recognition using the camera 28. First, the camera 28 displays an image of the traveling lane in which the vehicle 11 is currently traveling on the screen 29. Next, the identification device 30 displays the guardrail 2 on the screen 29 based on factors such as color and shape.
5 and the position of the white line 26 are obtained. Then, the identification device 30
Calculates respective distances c and d from the center line h of the camera 28 to the guardrail 25 and the white line 26. If the width of the screen 29 is k, the width b of this traveling lane is expressed by the following equation.

B = (c + d) Q / k Further, the distance L ₁ is expressed by the following equation. L ₁ = cQ / k−W / 2 In this way, the data of the distance L ₁ and the road width b obtained by image recognition are sent to the obstacle detection unit 23, and based on the above equations (1) and (2). Two regions S ₁ and S ₂ are determined.

Next, FIG. 6 shows an example in which the vehicle 11 travels on a left curve. In this case, it is considered that the area S ₁ (hatched portion) on the left side of the light beam 31 in contact with the left end of the road does not need to detect an obstacle, so the detection data from this area S ₁ is not used. .. The angle Φ ₀ formed by the light beam 31 and the traveling direction Y of the vehicle 11 is expressed by the following equation.

Φ ₀ = (b × R) ^1/2 / R−β where: b: lane width R: turning radius of curve β: vehicle side slip angle.

Therefore, assuming that the angle formed by an arbitrary light beam with respect to the traveling direction Y of the vehicle 11 is Φ, the detection data from the region satisfying Φ ≧ Φ ₀ (3) is not adopted. Further, the area S ₂ on the right side of the road where the detection data is not adopted is determined as follows.

First, the angle Φ _P formed by the point P where the light beam reaching the maximum detection distance L _X intersects the right end of the road with the traveling direction Y of the vehicle 11 is obtained. Next, the distance L _Q between the light emitting device 13 and the point Q at which the light beam 32 at the right end of the obstacle detection area 15 having the divergence angle δ intersects the right end of the road is obtained. Since the area S ₂ outside the line segment PQ connecting these two points P and Q is less necessary to detect an obstacle, the detection data from this area S ₂ (hatched area) is not adopted.

Similarly to the above, when the polar coordinates of an arbitrary point inside the obstacle detection area 15 are represented by (r, θ), the area S ₂ is represented by the following equation. r> [(θ-δ / 2) L x + (Φ P -θ) L Q ] _{/ (Φ P -δ / 2)} ··· ··· (4) then travels right curve in FIG. 7 An example of the case is shown. This case is basically the same as the case of the left curve shown in FIG.

First, the angle Φ _P formed by the point P where the light beam reaching the maximum detection distance L _X intersects with the left end of the road and the traveling direction Y of the vehicle 11 is obtained. Next, the distance L _Q between the light emitting device 13 and the point Q at which the beam light 33 at the left end of the obstacle detection area 15 having the divergence angle δ intersects the left end of the road is obtained. Since the area S ₁ outside the line segment PQ connecting these two points P and Q is less necessary to detect an obstacle, the detection data from this area S ₁ is not adopted.

Similar to the above, if polar coordinates (r, θ) are used as the coordinates of an arbitrary point in the obstacle detection area 15, the area S is obtained.
₁ is represented by the following equation. r> [(δ / 2−θ) L _x + (θ−Φ _P ) L _Q ] / (δ / 2−Φ _P ) ... (5) Next, the beam light 34 in contact with the right end of the road A region S ₂ (hatched portion) on the right side can be represented by Φ ≧ Φ ₀ (6), where Φ is an angle formed by an arbitrary light beam with the traveling direction Y of the vehicle 11.

Here, at the angle Φ _0, the light beam 34 is emitted by the vehicle 1
It is an angle formed with the traveling direction Y of 1 and is represented by the following equation. Φ ₀ = (b × R) ^1/2 / R−β where, b: lane width R: turning radius of curve β: vehicle side slip angle.

As shown in the above equations (3) to (6),
The larger the vehicle speed v or the steering angle θ, or the smaller the turning radius R, the larger the two regions S ₁ and S _{2 for} which detection data is not adopted. FIG. 8 shows a procedure for setting the above-mentioned areas S ₁ and S ₂ in the obstacle detection area 15. The controller 17 first determines whether or not the ignition switch is turned on (step S
1) If the determination result is YES, the controller 17 inputs a signal indicating the steering angle θ, the vehicle speed v from each sensor 18, and the left distance L ₁ from the ultrasonic sensor 27 (step S2).

Next, the controller 17 calculates the vehicle body side slip angle β, the vehicle turning radius R and the maximum detection distance Lx based on these signals (steps S3 and S4), and the spread angle δ based on the maximum detection distance Lx. Set (step S5). By setting the maximum detection distance Lx and the divergence angle δ, the obstacle detection region 15 is formed when traveling on a straight road.

Next, the controller 17 determines whether or not the steering angle θ is zero (step S6). If the determination result is YES, that is, if it is recognized that the vehicle 11 is traveling on a straight road, the two regions S shown in FIG. 3 based on the above equations (1) and (2). ₁ and S ₂ are set (step S7).

When the determination result is NO, the controller 17 further determines whether or not the steering angle θ is positive (step S8). In this case, the steering wheel is turned clockwise when the steering angle θ is positive, and the steering wheel is turned counterclockwise when the steering angle θ is negative. When the result of this determination is NO, that is, when the steering wheel is turned counterclockwise and the vehicle 11 is recognized to be traveling in the left curve, the following equations (3) and (4) are used. The two areas S ₁ and S ₂ shown in 6 are set (step S9).

On the other hand, when the determination result is YES, that is, when the steering wheel is turned clockwise and it is recognized that the vehicle 11 is traveling in the right curve, the above equation (5) is used.
And the two regions S ₁ and S shown in FIG. 7 based on (6)
₂ is set (step S10). In this way, by going through steps S6 to S10, the obstacle detection area 15
An area excluding the _two areas S ₁ and S ₂ is set, that is, a data adoption area in which obstacle detection data is adopted.

Next, the controller 17 detects the directions φ _i of all obstacles existing in the obstacle detection area 15 and the distances n _i to the obstacles (step S11), and adopts data among these obstacles. Direction of obstacles in the area φ
Select _j and distance n _j (step S12). Next, the controller 17 obtains the direction φ of the closest obstacle among these obstacles in the data adoption area and the distance n (step S13).

Next, the controller 17 executes a danger judging routine to judge the degree of danger of the obstacle (step S14). FIG. 9 shows a flowchart of the risk judgment routine. The controller 17 first obtains the relative speed V _j between the vehicle 11 and the obstacle from the change in the distance n _j of the obstacle (step S1).

Next, thresholds l ₁ , l ₂ , l for judging the degree of danger from the road surface friction coefficient μ, the relative speed V _j , and the 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 value 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 judges 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 the driver's attention for the time being, it is determined to be the 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.

[0047]

According to the present invention, the obstacle detection data from the area where it is not necessary to detect the obstacle, for example, the area outside the guardrail, the oncoming lane, or the area outside the curve in the radial direction, is not used. The risk of detection can be minimized, and it is possible to prevent adverse effects on the psychological state of the driver due to erroneous detection.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram of an obstacle detection device according to an embodiment of the present invention.

FIG. 3 is a plan view conceptually showing an obstacle detection data adoption region of the vehicle when traveling on a straight road.

FIG. 4 is a plan view and a side view of a vehicle that performs image recognition.

FIG. 5 is a flowchart of image recognition.

FIG. 6 is a plan view conceptually showing an obstacle detection data adoption region of the vehicle when traveling on a left curve.

FIG. 7 is a plan view conceptually showing an area in which obstacle detection data of a vehicle is used when traveling on a right curve.

FIG. 8 is a flowchart for setting an obstacle detection data adoption area.

FIG. 9 is a flowchart of a routine for determining a risk level.

[Explanation of symbols]

 11 Vehicle 13 Light-Emitting Device 14 Beam Light 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 24 Straight Road 25 Guardrail 26 White Line 27 Ultrasonic Wave Sensor 28 Camera 29 screen

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

Claims (4)

[Claims] 1. An obstacle detection device for detecting an obstacle located in a predetermined region ahead of a vehicle in a traveling direction, wherein detection data of an obstacle located in a set region of the region is adopted. An obstacle detection device for a vehicle, characterized in that it does not. 2. The obstacle detection device for a vehicle according to claim 1, wherein a distance from the vehicle to an installation on the side of the road is detected, and the setting area is set according to the distance. 3. When the vehicle is traveling on a straight road,
The obstacle detection device for a vehicle according to claim 1, wherein an area of an oncoming lane is set as the set area. 4. When the vehicle is traveling on a curved road,
The obstacle detection device for a vehicle according to claim 1, wherein an area on an outer side of the curved road in a radial direction is set as the set area.