JPH05151500A - Travel environment recognizing device - Google Patents

Abstract

PURPOSE:To provide a travel environment recognizing device which decides the proceeding car really in an emergency state regardless of a curve, junction, etc. CONSTITUTION:This device is provided with a relative position detecting means 1 detects proceeding car's position against an driving car, a travelling direction detecting means 2 which detects the preceeding car's travelling direction in relation with the driving car based upon the detected relative position and an emergency level calculating means 3 which decides an emergency state when preceeding car's travelling direction is identical with that of the driving car in an coordinate system on the driving car position reference, with the driving car's travelling direction being an axis. Therefore, regardless of a curved road, a junction, etc., the preceeding car really in an emergency state is discriminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling environment recognizing device capable of judging a preceding vehicle in a truly emergency state from preceding vehicles located in front of the own vehicle.

[0002]

2. Description of the Related Art As a conventional traveling environment recognition device, for example, as shown in FIGS. 16 to 18, when the inter-vehicle distance from a preceding vehicle B in the traveling direction of a vehicle A is shorter than a predetermined safety inter-vehicle distance. There is a distance detection method that determines an emergency.
That is, the distance detecting means 21 for detecting the distance between the preceding vehicle B and the own vehicle A, the preceding vehicle speed detecting means 22 for detecting the speed of the preceding vehicle B, and the own vehicle speed for detecting the speed of the own vehicle A. Comparison is made between the detection means 23, the safety inter-vehicle distance calculation means 24 for calculating the safety inter-vehicle distance according to the detected speeds of the preceding vehicle B and the own vehicle A, and the calculated safety inter-vehicle distance and the current inter-vehicle distance. And an urgency determination means 25 for determining the urgency,
Warning means 26 for issuing a warning when the urgency is above a certain level
It consists of and.

As another method, there is an azimuth detecting method for detecting the azimuth of the trajectory of the preceding vehicle B with respect to the own vehicle A as shown in FIG. 19 (see Japanese Patent Laid-Open No. 3-16846).
That is, the distance detecting means 31 for detecting the distance between the own vehicle and the preceding vehicle, the safe inter-vehicle distance calculating means 32 for calculating the safe inter-vehicle distance while the vehicle is traveling, and the azimuth detecting means for detecting the azimuth of the preceding vehicle with respect to the own vehicle. 33, and the trajectory data of the preceding vehicle on the azimuth / distance coordinates based on the distance data to the preceding vehicle detected by the distance detecting means 31 and the azimuth data of the preceding vehicle detected by the azimuth detecting means 33. The locus data detecting means 34, the approximating straight line calculating means 35 for calculating an approximate straight line of a plurality of locus data detected by the locus data detecting means 34 every predetermined time, and the approximate straight line calculating means 35. Lane identity that determines the identity between the lane of the preceding vehicle and the lane of the own vehicle based on whether or not the approximate straight line passes near the origin on the above coordinates The preceding vehicle detected by the distance detecting means 21 when the determining means 36 and the lane identity determining means 36 determine that the traveling lane of the preceding vehicle and the traveling lane of the own vehicle are the same. And a warning means 37 for issuing a warning when the distance to the safety inter-vehicle distance is equal to or less than the safe inter-vehicle distance.

[0004]

However, in the former distance detection method, the direction of the preceding vehicle B with respect to the own vehicle A is not detected, and the judgment is made only by the distance at the present time.
It may not be possible to determine whether or not the preceding vehicle B, which is actually located in front of the own vehicle, will actually collide with the own vehicle A by traveling as it is. For example, as shown in FIG. 17, when the own vehicle A and the preceding vehicle B are traveling on a straight road, it can be determined from the distance between the two vehicles whether the preceding vehicle B collides with the own vehicle A. As shown in FIG. 18, when the road is curved, it cannot be distinguished from the preceding vehicle B ′ in the other lane that is traveling in the other lane, and it is determined that the vehicle is in an emergency state. There is a risk of doing so. Similarly, a vehicle crossing the front of the own vehicle A cannot be distinguished from a preceding vehicle in the own lane, or there is no preceding vehicle in the front of the own lane at this moment, but the vehicle travels from another lane toward a collision with the own vehicle. There is also the risk of overlooking the coming vehicle.

Further, the latter azimuth detecting method is a method for detecting the azimuth of the trajectory of the preceding vehicle, so that the preceding vehicle in the own lane can be selected and detected more accurately than the preceding distance detecting method. However, this method has the drawbacks that it takes a long time to make the determination because it is a method that follows the trajectory, and that the determination is made based on the coordinates of the distance and the azimuth, so that it is not effective except for a curve.

An object of the present invention is to judge whether or not a preceding vehicle is traveling at a speed and in a direction toward a collision with the own vehicle, and determine whether or not the preceding vehicle is in a truly emergency state regardless of a curve or a merging point. The object is to provide a traveling environment recognition device that can make a judgment.

[0007]

A basic configuration of a traveling environment recognition apparatus according to the present invention will be described with reference to FIG. That is, this traveling environment recognition device detects relative position detecting means 1 for detecting the relative position of the preceding vehicle with respect to the own vehicle, and traveling direction detection for detecting the traveling direction of the preceding vehicle with respect to the own vehicle based on the detected relative position. Means 2 and urgency degree calculation means 3 for judging an emergency state when the traveling direction of the preceding vehicle is the own vehicle direction in the coordinate system based on the own vehicle position centering on the traveling direction of the own vehicle. It is a thing.

[0008]

According to the present invention, the relative position of the preceding vehicle with respect to the own vehicle is detected, the traveling direction of the preceding vehicle is detected based on the relative position, and the traveling direction of the preceding vehicle is the traveling direction of the own vehicle. Since it is determined whether or not it is the vehicle direction in the coordinate system of the vehicle position reference based on the axis, the direction in which the vehicle traveling in front of the vehicle is traveling toward the collision with the vehicle even when traveling in a curve or at a merging portion, By judging whether or not the vehicle is traveling at high speed, it is possible to judge the preceding vehicle that is in a truly emergency state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 2 to 11 are views showing a first embodiment of the present invention. First, the configuration of the traveling environment recognition apparatus according to this embodiment is shown in FIG. That is, the traveling environment recognition device includes a distance detecting means 11 for detecting the distance of the preceding vehicle to the own vehicle by a laser radar mounted on the own vehicle, and a direction detecting means 12 for detecting the direction of the preceding vehicle with respect to the own vehicle. The relative position detecting means 1, the relative speed detecting means 13 for detecting the relative speed of the preceding vehicle to the own vehicle by inputting the signals from the both detecting means, and the relative speed direction detecting means for detecting the direction of the relative speed. In the coordinate system based on the vehicle position with the traveling direction of the vehicle as an axis, the direction of the relative speed is the vehicle direction for a predetermined duration or longer and the distance to the preceding vehicle. Is basically provided with an urgency degree calculating means 15 for determining an emergency state when a margin time obtained by dividing by is a predetermined value or less.

Next, the basic pattern of this embodiment will be described with reference to FIGS. The actual (absolute coordinate system) relationship between the host vehicle A and the preceding vehicle B will be described with reference to FIG. The vehicle A is straight at the speed V ₀ (in the direction of the vertical axis)
Is in progress. On the other hand, the preceding vehicle B located to the right front of the own vehicle A is traveling at the speed V ₁ in the direction (obliquely left side) that interferes with the course of the own vehicle A.

Next, a description will be given with reference to FIG. 4 showing the relationship between the two vehicles in a coordinate system centering on the own vehicle A. Since the straight traveling component V _1V of the preceding vehicle B and the speed V ₀ of the own vehicle A are V ₀ > V _1V , the relative speed of the preceding vehicle B with respect to the own vehicle A in the straight traveling direction is (V _1V −
V ₀ ). Since the velocity V _1H in the direction (horizontal axis) orthogonal to the straight ahead direction of the preceding vehicle B does not change, the own vehicle A of the preceding vehicle B
Relative velocity Vs becomes to be synthesized by the V _IH and (V _1V -V _0). Then, if the direction of the relative speed Vs is toward the host vehicle A, the preceding vehicle B becomes a “vehicle requiring attention” with respect to the host vehicle A at that time.

Next, the function of the traveling environment recognition apparatus according to this embodiment will be described with reference to FIGS. 5 and 6 based on a more specific example. For example, in the situation as shown in FIG. 5, that is, in front of the own vehicle A traveling in the central lane,
When the preceding vehicle B changes the lane from the front right lane to the left lane over the central lane, the preceding vehicle B only passes the central lane momentarily, which is not an emergency for the host vehicle A.

That is, in the traveling environment recognition apparatus of this embodiment, as shown in FIG. 6, the emergency state is judged based on the direction of the relative speed Vs, and the direction of the relative speed Vs of the preceding vehicle B is the own vehicle A. Since it is not heading for, it is not judged as an emergency.

Next, the junction of the road will be described with reference to FIGS. 7 and 8. That is, it shows a case in which the vehicle A collides with the preceding vehicle B when the vehicle A proceeds as it is at the merging portion as shown in FIG. 7. Even in such a case, as shown in FIG. 8, in order to detect that the direction of the relative speed Vs of the preceding vehicle B is facing the own vehicle A, it is necessary to recognize that the preceding vehicle B is in an emergency state from the beginning. You can The same function as in the merging portion is the same when the preceding vehicle makes a sudden lane change from another lane to the own lane.

Next, with reference to FIG. 9, the possibility of adding correction means to the basic structure of the present traveling environment recognition device during traveling on a curve will be described. That is, a means for estimating the radius of a curve while traveling from the absolute speed and steering angle information of the own vehicle, and position information (distance, direction, etc.) of the preceding vehicle with respect to the own vehicle.
A case will be described in which a preceding vehicle is recognized on a curved road by means for determining whether the vehicle is in the same arc as the own lane and for estimating the traveling direction of the preceding vehicle with respect to the own vehicle by subtracting the influence of the curve.

That is, when the vehicle is traveling on a curve, the radius R of the curve is estimated from the speed V _{0 of the} vehicle and the steering angle θ. This is given by the following equation as is well known.

R = V ₀ / r = L (1 + K _S · V ₀ ² ) · N / θ where yaw rate: r steering gear ratio: N wheelbase: L stability factor: K _S where r = V ₀・ Θ / (L (1 + K _S · V ₀ ² ) · N) When R is obtained, the distance d to the preceding vehicle on the same circular arc and the direction α are given by the following equations. d = 2R sin (α / 2)

Therefore, when the preceding vehicle is detected, the distance d and the direction are checked, and only the preceding vehicle having this relationship can be recognized as the preceding vehicle in the own lane.

In addition to this, the speed direction of the preceding vehicle is corrected by the angle α as shown in FIG. That is,
If you are traveling on an arc, you will be facing the same direction as your vehicle. Therefore, if the relative speed is negative, the vehicle will be heading in the direction of the host vehicle and is recognized as a vehicle requiring attention.

Next, the processing of this traveling environment recognition apparatus will be described with reference to the flowchart of FIG. First, the direction / distance of the preceding vehicle is detected using the distance detecting means and the direction detecting means such as a laser radar with scanning (step 101). Then, this data is differentiated to calculate the relative speed and relative direction of the preceding vehicle on the basis of the own vehicle (step 10).
2). Next, when the steering angle is a certain value or more, the radius gyration R is calculated from the vehicle speed and the steering angle (step 103). As a result, the position and speed of the preceding vehicle are corrected, and it is determined whether the preceding vehicle is in the own lane (step 104). If the vehicle is in the own lane, the process proceeds to step 105, and if not, the process returns to 101. Next, it is determined whether or not the preceding vehicle is heading in the direction of the own vehicle based on the relative position and relative speed of the preceding vehicle in the coordinate system having the own vehicle as the origin (step 10).
5). If it is not heading, the process returns to 101, and if it is heading, the time (duration T) during which the preceding vehicle is heading to the host vehicle is measured and input (step 10).
6). Then, a value obtained by dividing the relative distance from the preceding vehicle by the relative speed, that is, the margin time t until the collision is calculated and input (step 107).

This margin time t is a predetermined value t
It is judged whether it is less than ₀ (step 10).
8). When the margin time t is the value t ₀ or more, the process returns to 101. When the allowance time t is smaller than the value t ₀ , the allowance time t is defined as the emergency determination value and the process proceeds to step 109. In step 109, the duration setting value T ₀ is calculated.

More specifically, the vehicle requiring attention means that the time (duration T) satisfying the condition that the direction of the relative speed is the vehicle direction is longer than this set value T _0. .. Therefore, finally, in step 110, it is determined whether the duration T is larger than the set value T ₀ ,
When it is large, an alarm is issued in step 111, and then the process returns to 101. If the duration T is less than or equal to the set value T ₀ , the process returns to 101 without issuing an alarm.

It should be noted that the continuation time set value T ₀ is the margin time t
It is even better to change by. That is, when the margin time t is long, the duration setting value T ₀ is set long, and when the margin time t is short, the duration setting value T ₀ is set short. This means that when the margin time t is sufficient, it takes time to make a decision, and when the margin time t is not so much, it makes an instant decision.

In addition to this, in the emergency judgment, a method of detecting a caution vehicle which has become less than the safe inter-vehicle distance conventionally known and issuing an alarm may be used together. In this case, the inter-vehicle distance also becomes an emergency determination value.

As described above, according to the first embodiment, the traveling direction of the preceding vehicle is actually the vehicle direction in the coordinate system based on the vehicle position with the traveling direction of the vehicle as an axis. Since it is determined whether or not there is a preceding vehicle that is truly in an emergency state while traveling on a curve or at a confluence.

12 and 13 are views showing a second embodiment of the present invention. First, the situation where the host vehicle A is parked will be described with reference to FIG. Two preceding vehicles B and C are located on the left and right sides of the host vehicle A. The relative speeds (a) and (b) from one preceding vehicle B with respect to the direction area X of the own vehicle A and the relative speeds (c) and (d) from the other preceding vehicle C can be detected. Is becoming

Next, the processing of this traveling environment recognition apparatus will be described with reference to the flowchart of FIG. In this example,
The states of the two preceding vehicles B and C are recognized at the same time, and step 207 of calculating the margin time t from step 201 is performed.
Up to this, it is the same as in the first embodiment. In this embodiment, after calculating the margin time t, the duration setting value T ₀ is calculated in step 208. Then, in step 209, it is determined whether or not the duration time T is larger than the set value T ₀ , and then in step 210, it is determined whether or not the allowance time t is smaller than a predetermined value t _0. When the condition of is satisfied, an alarm is issued in step 211.

Then, in step 212, the direction of the relative speed of the preceding vehicles B and C is the relative speed (b),
(c) is judged, and if so, there is a risk of collision with the preceding vehicle B or the preceding vehicle C if the own vehicle A proceeds as it is. The relative speed of B or the preceding vehicle C should not be directed toward the own vehicle A. When the relative speeds of the preceding vehicles B and C are (a) and (d), the brake is not applied.

As described above, according to the second embodiment, the relative speeds of the preceding vehicles B and C with respect to the own vehicle A are respectively detected, and the direction of the relative speed is determined by the own vehicle in the coordinate system. If the preceding vehicles B and C are suitable for the vehicle A and the vehicle A is truly in an emergency state, the automatic brake can be applied to avoid the emergency state.

FIG. 14 is a diagram showing a third embodiment of the present invention. The situation between the own vehicle A and the preceding vehicles B and C in this embodiment is the same as in the case of FIG. Also, in the flowchart shown in FIG. 14, the basic flow from steps 301 to 313 is the same as in the case of FIG. Steps 314 and 315 are different from the flowchart of FIG. That is, in the basic flow of steps 301 to 313, as described above, the relative speeds of the preceding vehicles B and C are (b),
In the case of (c), the brakes are automatically applied until the relative speeds of the preceding vehicles B and C do not turn in the direction of the own vehicle A.

Then, in steps 314 and 315, the relative speeds of the preceding vehicles B and C are (a) and (d) in FIG. 12 even if the margin time t is equal to or greater than the predetermined value t ₀ in step 310. In the case of, if the brake is applied, the possibility of collision further increases, and thereafter the possibility of collision decreases, so the brake is applied only when the allowance time t is larger than the sufficient set time t ₁ where the possibility of collision is small. It was done like this.

As described above, even when the margin time t is equal to or greater than the predetermined value t ₀ and is safe, the preceding vehicle B,
Depending on the direction of the acceleration of C, applying the brake may rather bring about an emergency. However, by performing the third embodiment, it is possible to avoid such an unexpected situation. You can

FIG. 15 is a diagram showing a fourth embodiment of the present invention. The situation between the own vehicle A and the preceding vehicles B and C in this embodiment is also the same as in the case of FIG. Also in the flowchart shown in FIG. 15, the basic flow from steps 401 to 413 is the same as in the case of FIG. FIG.
Steps 414 and 415 are different from the flowchart in FIG.
Is. That is, the relative speeds of the preceding vehicles B and C are (a) and (d)
In the case of 2, the accelerator is automatically stepped on to increase the acceleration of the own vehicle A, and the preceding vehicle B or the preceding vehicle C is pulled out to reduce the urgency of the collision.

As described above, depending on the acceleration directions of the preceding vehicles B and C, in order to avoid an emergency,
In some cases, it may be better to increase the acceleration of the host vehicle A by stepping on the accelerator. Therefore, in the fourth embodiment, when such a situation is detected, the acceleration of the host vehicle A is increased to set the preceding vehicles B and C. It is designed to be pulled out to ensure a safe driving condition.

[0035]

The traveling environment recognition device according to the present invention is
Since the contents are as described above, it is truly an emergency state whether or not the preceding vehicle is traveling in the direction and speed toward the collision with the own vehicle even during the curve traveling or the merging portion. This has the effect of being able to reliably determine the preceding vehicle.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a traveling environment recognition device of the present invention.

FIG. 2 is a block diagram showing the configuration of a traveling environment recognition apparatus according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a vehicle and a preceding vehicle on an absolute coordinate system.

FIG. 4 is a diagram showing a relationship between a vehicle and a preceding vehicle on a vehicle coordinate system.

FIG. 5 is a diagram showing a relationship between the own vehicle and a preceding vehicle on an absolute coordinate system on an actual road.

FIG. 6 is a diagram showing a relationship between a host vehicle and a preceding vehicle on an actual vehicle coordinate system on an actual road.

FIG. 7 is a diagram showing a relationship between the own vehicle and a preceding vehicle on an absolute coordinate system at a merging portion.

FIG. 8 is a diagram showing a relationship between a vehicle and a preceding vehicle on a vehicle coordinate system at a merging portion.

FIG. 9 is a curve radius R and a vehicle speed V in a curve traveling
_The figure which shows the relationship between ₀ and steering wheel turning angle (theta).

10 is a diagram corresponding to FIG. 10 showing a case where the direction of speed of a preceding vehicle is corrected by an angle α.

FIG. 11 is a flowchart illustrating the processing of the first embodiment.

FIG. 12 is a diagram for explaining a situation between a host vehicle and a preceding vehicle in the second embodiment.

FIG. 13 is a flowchart illustrating processing of the second embodiment.

FIG. 14 is a flowchart illustrating the processing of the third embodiment.

FIG. 15 is a flowchart illustrating the processing of the fourth embodiment.

FIG. 16 is a block diagram showing a configuration of a conventional distance detection method.

FIG. 17 is a diagram showing a distance detection situation on a straight road.

FIG. 18 is a diagram showing a distance detection situation on a curved road.

FIG. 19 is a block diagram showing a configuration of a conventional azimuth detection method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Relative position detecting means 2 Traveling direction detecting means 3, 15 Urgency calculating means 11 Distance detecting means 12 Direction detecting means 13 Relative speed detecting means 14 Relative speed direction detecting means A Own vehicle B, C Preceding vehicle

Claims (7)

[Claims] 1. A relative position detecting means for detecting a relative position of a preceding vehicle with respect to the own vehicle, a traveling direction detecting means for detecting a traveling direction of the preceding vehicle with respect to the own vehicle based on the detected relative position, and a own vehicle. And an urgent degree calculating means for determining an emergency state when the traveling direction of the preceding vehicle is the own vehicle direction in a coordinate system based on the own vehicle position with the traveling direction of the vehicle as the axis. Recognition device. 2. The relative position detecting means comprises a distance detecting means for detecting a distance of the preceding vehicle to the own vehicle and a direction detecting means for detecting a direction of the preceding vehicle with respect to the own vehicle. Comprising a relative speed detecting means for detecting the relative speed of the preceding vehicle with respect to the vehicle and a relative speed direction detecting means for detecting the direction of the relative speed, and the emergency calculating means has the own vehicle centered on the traveling direction of the own vehicle. The traveling environment recognition device according to claim 1, wherein an emergency state is determined when the direction of the relative speed is the vehicle direction in the position-based coordinate system. 3. The urgency calculation means determines that the direction of the relative speed is the direction of the own vehicle for a predetermined duration or longer and the margin time obtained by dividing the distance to the preceding vehicle by the relative speed is less than or equal to a predetermined value. The traveling environment recognition device according to claim 2, wherein the traveling environment recognition device judges that the vehicle is in an emergency state. 4. The traveling environment recognition device according to claim 3, wherein the longer the margin period is, the longer the duration time is. 5. A means for estimating a curve radius while traveling from the own vehicle's absolute speed and steering angle information, a means for judging from the position information of the preceding vehicle with respect to the own vehicle whether or not it is the same arc as the own lane, and the preceding The driving environment recognition device according to claim 2, further comprising: a unit that estimates a traveling direction of the vehicle with respect to the own vehicle by subtracting an influence of a curve. 6. The traveling environment recognition device according to claim 1, wherein an alarm is given when the emergency level calculation means determines that the emergency state is present. 7. The traveling environment recognition device according to claim 1, wherein when the emergency calculation means determines that it is in an emergency state, the braking control means is instructed to automatically apply the braking force.