JPH05166098A - Automatic cruise system - Google Patents

Abstract

PURPOSE:To obtain the safety automatic cruise system by regarding maintaining the distance between cars before and behind. CONSTITUTION:A means 6 recognizing cars ahead and a means 7 recognizing cars behind recognize vehicles in front of and behind the car based on the picture obtained by a front image pickup means 1 and a back image pickup means 2. A means 8 for calculating the distance from car ahead and a means 9 for calculating the distance from car behind calculate the recognized distance between cars. The safety distance between cars is calculated by using a means 10 storing braking distance, means 11 calculating safety distance from the car ahead, means 12 calculating safety distance from the car behind. A means 13 discriminating car control discriminates the car control based on the distance between cars, running speed, speed limit, cruising speed, safety distance from the car ahead, and safety distance from the car behind. Based on the judgment, a car speed control means 15 controls the car speed and a warning means 14 for the car behind warns the car behind as necessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic cruise device for automatically controlling the speed of a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, as an auto cruise device of this type, as described in, for example, Japanese Patent Laid-Open No. 64-66712, an image in front of the vehicle is input from a CCD camera installed in the front of the vehicle. In some cases, the front vehicle is recognized from the obtained image, and the speed of the own vehicle is controlled based on the distance between the recognized front vehicle and the own vehicle.

[0003]

However, in such a conventional auto-cruise device, since the speed of the host vehicle is controlled only from the inter-vehicle distance to the vehicle in front,
Acceleration / deceleration is performed regardless of the inter-vehicle distance to the other vehicle behind. Therefore, when the distance between the front vehicle and the front vehicle suddenly decreases, the rear vehicle may rapidly decelerate even when the rear vehicle is close to the host vehicle, and there is a possibility that the rear vehicle may collide with the rear vehicle. Was there.

The present invention solves the problems as described above, and pays attention not only to the inter-vehicle distance to the vehicle existing in front of the host vehicle but also to the relative positional relationship to the vehicle existing in the rear. The purpose of the present invention is to provide an auto-cruise device that performs highly safe automatic speed control.

[0005]

In order to achieve the above object, according to the present invention, a front imaging means for front photographing, a rear imaging means for rear photographing, and a vehicle speed for detecting a vehicle speed are mounted on a vehicle. Detecting means, speed limit setting means for setting a speed limit on a traveling road, cruising speed setting means for setting cruising speed, and forward vehicle recognizing means for recognizing a forward vehicle from an image captured by the front image capturing means. A rear vehicle recognizing means for recognizing a rear vehicle from an image captured by the rear image capturing means, and a front inter-vehicle distance calculating means for calculating an inter-vehicle distance between the front vehicle and the own vehicle recognized by the front vehicle recognizing means. A rear inter-vehicle distance calculating means for calculating the inter-vehicle distance between the rear vehicle and the host vehicle recognized by the rear vehicle recognizing means, and a braking stop distance according to the traveling speed of the vehicle. The braking stop distance storage means, the front inter-vehicle distance calculated by the front inter-vehicle distance calculation means, the own vehicle speed detected by the vehicle speed detection means, and the braking stop distance stored in the braking stop distance storage means. Front safe inter-vehicle distance calculating means for calculating the safe inter-vehicle distance between the host vehicle and the front vehicle, the rear inter-vehicle distance calculated by the rear inter-vehicle distance calculating means, the own vehicle speed detected by the vehicle speed detecting means, and the braking stop. Rear safety inter-vehicle distance calculation means for calculating the safety inter-vehicle distance between the own vehicle and the rear vehicle from the braking stop distance stored in the distance storage means, and the front inter-vehicle distance and the rear calculated by the front inter-vehicle distance calculation means. The following vehicle distance calculated by the vehicle distance calculation means, the own vehicle speed detected by the vehicle speed detection means, and the vehicle speed set by the speed limit setting means. The speed limit, the cruising speed set by the cruising speed setting means, the front safety inter-vehicle distance calculated by the front safety inter-vehicle distance calculation means, and the rear safety inter-vehicle distance calculated by the rear safety inter-vehicle distance calculation means. Vehicle control determination means for determining vehicle control of a vehicle, rear vehicle warning means for issuing a warning to a rear vehicle based on the determination by the vehicle control determination means, and own vehicle based on the determination by the vehicle control determination means The device including the vehicle speed control means for controlling the vehicle speed is used as the problem solving means.

Further, in the present invention, 1 is calculated based on the change rate of the front inter-vehicle distance calculated by the front inter-vehicle distance calculating means.
Front inter-vehicle distance predicting means for predicting the front inter-vehicle distance after the sampling interval, and rear inter-vehicle distance for predicting the rear inter-vehicle distance after one sampling interval based on the change rate of the rear inter-vehicle distance calculated by the rear inter-vehicle distance calculating means. Distance prediction means,
Front inter-vehicle distance calculated by front inter-vehicle distance calculation means, rear inter-vehicle distance calculated by rear inter-vehicle distance calculation means, own vehicle speed detected by vehicle speed detection means, and speed limit and cruise speed set by speed limit setting means The cruise speed set by the setting means, the front safety inter-vehicle distance calculated by the front safety inter-vehicle distance calculating means, and the rear safety inter-vehicle distance calculated by the rear safety inter-vehicle distance calculating means and the front inter-vehicle distance predicting means Based on the judgment by the vehicle control judgment means for judging the vehicle control of the own vehicle from the predicted value of the front inter-vehicle distance and the predicted value of the rear inter-vehicle distance predicted by the rear inter-vehicle distance prediction means, and the judgment by the vehicle control judgment means. A device including a driver warning means for issuing a warning to the driver is used as the problem solving means.

[0007]

According to the present invention, the above-mentioned means for solving the problems makes it possible to take into consideration not only the inter-vehicle distance to the other vehicle existing in the front, but also the relative positional relationship to the other vehicle existing in the rear.
In the situation where the rear vehicle is close to the vehicle, the automatic speed control with high safety can be realized because the vehicle does not suddenly decelerate even if the inter-vehicle distance with the vehicle in front becomes narrow.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the basic configuration of the first embodiment of the present invention. Reference numeral 1 is a front imaging means for photographing the front of the vehicle, and 2 is a rear imaging means for photographing the rear of the vehicle. As shown in FIG. 2, the front image pickup unit 1 and the rear image pickup unit 2 are realized by installing CCD cameras at the front and rear of the vehicle so as not to obstruct the driver's view. Reference numeral 3 is a vehicle speed detecting means for outputting the traveling speed V of the own vehicle in real time, and specifically, an existing speedometer is used. Reference numeral 4 denotes a speed limit setting means for setting the speed limit VL on the traveling road, which is set by the driver using a ten-key pad or the like. Reference numeral 5 denotes a cruise speed setting means for setting the cruise speed VC, which sets the traveling speed at the time when the setting switch is turned on as the cruise speed.
Reference numeral 6 is a front vehicle recognition means for recognizing a front vehicle from an image captured by the front imaging means 1 by using an image processing technique, and 7 is an image captured by the rear imaging means 2 using the same image processing technique. Is a rear vehicle recognition means for recognizing a rear vehicle. Reference numeral 8 is a front inter-vehicle distance calculating means for calculating the inter-vehicle distance F with the front vehicle recognized by the front vehicle recognizing means 6, and 9 is for calculating the inter-vehicle distance R with the rear vehicle recognized by the rear vehicle recognizing means 7. It is a rear inter-vehicle distance calculating means. Reference numeral 10 is a braking stop distance storage means for storing a braking stop distance according to the traveling speed of the vehicle, and the value is set in advance. The braking stop distance D (m) is a distance required for the vehicle to stop braking, and is the traveling speed V (km / h) of the vehicle, the coefficient of longitudinal sliding friction between the tire and the road surface f, and the reaction time t (seconds). Is expressed by D = Vt / 3.6 + V ² /2gf(3.6) ² (1). In the formula (1), the first term Vt / 3.6 is a free running distance from when the driver recognizes the braking of the vehicle ahead to when it shifts to the braking of the own vehicle, and the free running distance = reaction time × speed (2 ) Is required. The reaction time is composed of a judgment time for judging whether the driver depresses the brake and a reaction time from the judgment until the driver depresses the brake. The second term is the distance that the vehicle moves from when the brake starts to work until it stops. At this time, the longitudinal slip coefficient f varies depending on the running condition of the vehicle, tire condition (air pressure, rubber quality, wear condition, etc.), road condition (road material, dry / wet, road temperature, etc.). Therefore, the braking stop distance stored in the braking stop distance storage means 10 has a sufficiently safe value even in consideration of these states. Reference numeral 11 denotes the front inter-vehicle distance F calculated by the front inter-vehicle distance calculation means 8, the own vehicle speed V detected by the vehicle speed detection means 3, and the braking stop distance D of the own vehicle stored in the braking stop distance storage means 10. And the braking stop distance FD of the front vehicle, the front safety that calculates the inter-vehicle distance FS between the own vehicle and the front vehicle that allows the own vehicle to safely stop at a certain distance even when the front vehicle suddenly stops. It is an inter-vehicle distance calculating means. Similarly, 12 is the rear vehicle distance R calculated by the rear vehicle distance calculating means 9, the own vehicle speed V detected by the vehicle speed detecting means 3, and the braking stop of the own vehicle stored in the braking stop distance storing means 10. From the distance D and the braking stop distance RD of the rear vehicle, the inter-vehicle distance RS between the own vehicle and the rear vehicle, which allows the rear vehicle to safely stop at a certain distance even when the own vehicle suddenly stops, is calculated. It is a rear safety inter-vehicle distance calculation means. Reference numeral 13 denotes a front inter-vehicle distance F calculated by the front inter-vehicle distance calculating means 8, a rear inter-vehicle distance R calculated by the rear inter-vehicle distance calculating means 9, a traveling speed V detected by the vehicle speed detecting means 3, and a speed limit setting means 4. The speed limit VL on the set traveling path, the cruise speed VC set by the cruise speed setting means 5, the safe inter-vehicle distance FS between the own vehicle and the front vehicle calculated by the front safety inter-vehicle distance calculation means 11, and the rear safety It is a vehicle control determination means that determines the vehicle control from the safe inter-vehicle distance RS between the own vehicle and the rear vehicle calculated by the inter-vehicle distance calculation means 12. Reference numeral 14 is a rear vehicle warning means for giving a warning to the rear vehicle when the vehicle control determination means 13 determines that the inter-vehicle distance to the rear vehicle is short. Specifically, the brake light of the host vehicle is turned on to prompt the rear vehicle to decelerate. Reference numeral 15 is a vehicle speed control means for controlling the own vehicle speed according to the judgment by the vehicle control judgment means 13, and controls a throttle actuator and a brake actuator.

Next, the operation of the auto cruise device according to the first embodiment of the present invention will be described with reference to the flow chart shown in FIG.

First, in step 101, the vehicle control parameter CNT is initialized and the process proceeds to the following process (C
Initial value of NT = 0).

At step 102, the speed limit VL on the road is set by the speed limit setting means 4. FIG. 4 shows a flow of a series of processes in the speed limit setting means 4. Since the speed limit VL is different for each road, the driver recognizes the speed limit of the road on which the vehicle is traveling from road signs,
When it is determined in step 201 that the speed limit VL needs to be changed, the speed is changed to a speed limit corresponding to the road on which the vehicle travels in step 202. On the contrary, when the driver determines in step 201 that the speed limit VL does not need to be changed, the driver does not change the speed limit VL, and step 103 in FIG.
Go to.

At step 103, the cruise speed VC is set by using the cruise speed setting means 5. FIG. 5 shows a flow of a series of processes in the cruise speed setting means 5. Cruising speed V
Since C needs to change according to the traffic situation and the psychological state of the driver, if the driver determines in step 301 that the cruising speed VC needs to be changed, in step 302, Change the cruising speed VC. On the contrary, when the driver determines that it is not necessary to change the cruising speed VC, the process proceeds to step 303 with the state unchanged.
In step 303, the cruise speed VC and the speed limit VL are compared in order to comply with the speed limit on the traveling road. If it is determined in step 303 that the cruising speed VC does not exceed the speed limit VL, the process proceeds to step 104 in FIG. On the contrary, when it is determined that the cruising speed VC exceeds the speed limit VL, the speed limit VL is reset as the cruising speed VC in step 304, and then the process proceeds to step 104 in FIG.

In step 104, the vehicle speed detecting means 3 is used to input the traveling speed V of the host vehicle, and in step 105
Then, the process proceeds to step 109. In order to reduce the processing time, the processing from step 105 to step 108 and the processing from step 109 to step 112 are
It is also possible to perform them in parallel on different processors.

In step 105, an image of the front of the vehicle is input from the front image pickup means 1, and the process proceeds to step 106.
FIG. 11 shows the input image in front of the vehicle.

In step 106, the front vehicle recognition means 6
Is used to recognize the vehicle ahead from the input image. Figure 6
The flow of a series of processes in the front vehicle recognition means 6 is shown in FIG. First, in step 401, an edge is extracted from the input image in front of the vehicle. The extraction of edges is performed by applying a well-known spatial filter such as a Laplacian operator to the input image. The result of extracting the edges from the image of FIG. 11 is shown in FIG. Next, in step 402, a white line on the road is detected based on the edge image obtained in step 401. The white line is detected by HOUGH which transforms the straight line represented on the XY coordinate into a point on the θ-ρ coordinate.
This is done by using the method of conversion. As shown in FIG. 16, ρ is the length of a perpendicular line drawn from the straight line on the XY coordinates to the origin, and θ is the angle formed by the perpendicular line with the X axis. At this time, the group of straight lines that can pass through the point P _A on the XY coordinates shown in FIG. 16 is the curve L _A on the θ-ρ coordinates shown in FIG.
Is represented as Similarly, a group of curves that can pass through the point P _B on the X-Y coordinates is represented as a curve L _B on the θ-ρ coordinates. At this time, the intersection point P of the curves L _A and L _B is X−
It corresponds to the straight line L on the Y coordinate. Hou like this
According to the principle of the gh transform, a straight line on an image can be detected by combining a series of points having continuity or removing an isolated point having no continuity. FIG. 13 shows an image in which a white line is detected from the edge image of FIG. Although three white lines are detected in FIG. 13, two white lines near the center line of the road are recognized as the traveling lane. Further step 4
In 03, a trapezoidal area surrounded by the two recognized white lines, the uppermost scanning line in which the white line is detected, and the scanning line at the lower end of the image is defined as a road area, and the area on the image is limited. FIG. 14 shows an image obtained by limiting the road area to the image of FIG. In step 404, when horizontal edges are continuously detected in the vertical direction with respect to the scanning line in the limited road area, it is recognized that the vehicle is ahead. The extraction of edges in this case is performed by applying a known spatial filter such as a Laplacian operator to the road region of the input image.
FIG. 15 shows an image in which a vehicle ahead is recognized from the image of FIG.

In step 107 of FIG. 3, the inter-vehicle distance F between the front vehicle and the host vehicle thus recognized is calculated by the front inter-vehicle distance calculating means 8. The inter-vehicle distance can be easily calculated by associating each scanning line of the input image with the distance from the CCD camera on the road. For example, the distance to the lowest edge among the edge group corresponding to the front vehicle recognized on the image of FIG. 15 is calculated as the inter-vehicle distance to the front vehicle. At this time,
The distance F on the actual road corresponding to d shown in FIG. 15 is the inter-vehicle distance to the preceding vehicle.

In step 108 of FIG. 3, the safe inter-vehicle distance calculation means 11 is used to calculate the safe inter-vehicle distance FS between the host vehicle and the front vehicle. Here, the front safe inter-vehicle distance FS means the inter-vehicle distance at which the host vehicle can safely stop at a certain distance even when the front vehicle suddenly decelerates and stops. FIG. 8 shows a front safety inter-vehicle distance calculation means 1
1 shows a flow of a series of processes in 1. First, in step 601 of FIG. 8, the braking stop distance according to the traveling speed V of the own vehicle detected by the vehicle speed detecting means 3 is retrieved from the braking stop distance storing means 10 to calculate the braking stop distance D of the own vehicle.

In step 602, the inter-vehicle distance between the host vehicle and the front vehicle calculated by the front inter-vehicle distance calculating means 8 is compared with the value calculated from the current image and the value calculated from the image one sampling before. Perform and determine the amount of change.

In step 603, the relative speed between the host vehicle and the front vehicle is calculated based on the amount of change in the inter-vehicle distance F between the host vehicle and the front vehicle thus obtained. The relative speed FRV between the host vehicle and the preceding vehicle is FRV = ΔF / Δt (ΔF), where ΔF is the amount of change in the inter-vehicle distance between the host vehicle and the preceding vehicle, and Δt is the sampling interval of the image provided from the front imaging means 1. 3), and go to step 604.

In step 604, the traveling speed of the front vehicle is calculated from the relative speed FRV of the own vehicle and the front vehicle thus obtained and the own vehicle speed detected by the vehicle speed detecting means 3. Letting your vehicle speed be V, the traveling speed F of the vehicle ahead
V is calculated by FV = FRV + V (4), and the routine proceeds to step 605.

In step 605, the braking stop distance corresponding to the traveling speed of the vehicle ahead calculated in step 604 is
The braking stop distance storage means 10 is searched to calculate the braking stop distance FD of the vehicle ahead.

In step 606, the safe inter-vehicle distance FS between the host vehicle and the preceding vehicle is calculated using the braking stop distance D of the host vehicle calculated in step 601 and the braking stop distance FD of the preceding vehicle calculated in step 605. To do.

FIG. 18 shows the relationship between the inter-vehicle distance and the braking stop distance in the case where the own vehicle and the preceding vehicle traveling with the inter-vehicle distance F are stopped safely at a certain distance. Let F be the inter-vehicle distance between the host vehicle and the preceding vehicle, FD be the braking stop distance until the preceding vehicle brakes and stop, and D be the braking stop distance of the own vehicle. At this time, if FD + FD> 0 (5), the own vehicle and the preceding vehicle can be safely stopped without collision. That is, the safe inter-vehicle distance FS between the host vehicle and the preceding vehicle can be defined as a value that satisfies FS> D-FD (6).

Similar processing is performed for the rear vehicle. First, in step 109 of FIG. 3, an image of the rear of the vehicle is input from the rear image pickup means 2, and the process proceeds to step 110.

In step 110, the rear vehicle recognition means 7 recognizes the rear vehicle based on the input rear image of the vehicle. FIG. 7 shows a flow of a series of processes in the rear vehicle recognizing means. First, in step 501, an edge is extracted from the input image, and then in step 502, a white line is detected. Next, based on the detected white line, the road area is limited in step 503, and the rear vehicle is recognized in step 504.
Proceed to step 111 in FIG.

In step 111, the inter-vehicle distance R with the rear vehicle thus recognized is calculated by the rear inter-vehicle distance calculating means 9, and the process proceeds to step 112.

In step 112, the safe rear vehicle distance calculation means 12 is used to calculate the safe rear vehicle distance RS between the host vehicle and the rear vehicle. Here, the rear safety inter-vehicle distance RS means a distance at which the rear vehicle can safely stop at a certain distance even when the own vehicle suddenly decelerates and stops.

FIG. 9 shows a flow of a series of processes in the rear safety inter-vehicle distance calculating means 12. First, step 7 in FIG.
In 01, the braking stop distance according to the traveling speed of the own vehicle detected by the vehicle speed detecting means 3 is retrieved from the braking stop distance storing means 10 to calculate the braking stop distance D of the own vehicle.

In step 702, the value calculated from the current image and the value calculated from the image one sampling before are compared with respect to the inter-vehicle distance between the own vehicle and the rear vehicle calculated by the rear inter-vehicle distance calculating means 9. , Find the amount of change.

In step 703, the relative speed between the own vehicle and the rear vehicle is calculated based on the amount of change in the inter-vehicle distance between the own vehicle and the rear vehicle thus obtained. The relative speed RRV between the own vehicle and the rear vehicle is RRV = ΔR / Δ, where ΔR is the amount of change in the inter-vehicle distance between the own vehicle and the rear vehicle, and Δt is the sampling interval of the image provided from the rear imaging means 2. Obtained at t (7), the process proceeds to step 704.

In step 704, the traveling speed of the rear vehicle is calculated from the relative speed between the own vehicle and the rear vehicle thus obtained and the own vehicle speed detected by the vehicle speed detecting means 3. When the own vehicle speed is V, the speed RV of the rear vehicle is calculated by RV = RRV + V (8), and the routine proceeds to step 705.

In step 705, the braking stop distance corresponding to the traveling speed of the rear vehicle calculated in step 704 is retrieved from the braking stop distance storage means 10 to calculate the braking stop distance RD of the rear vehicle.

In step 706, the safe inter-vehicle distance RS between the own vehicle and the rear vehicle is calculated using the braking stop distance D of the own vehicle calculated in step 701 and the braking stop distance RD of the rear vehicle calculated in step 705. ..

FIG. 19 shows the relationship between the inter-vehicle distance and the braking stop distance in the case where the own vehicle and the rear vehicle traveling at the inter-vehicle distance R are stopped safely at a certain distance. Let R be the inter-vehicle distance between the own vehicle and the rear vehicle, D be the braking stop distance until the own vehicle brakes and stop, and RD be the braking stop distance of the rear vehicle. At this time, if D + R-RD> 0 (9), the own vehicle and the following vehicle can be safely stopped without collision. That is, the safe inter-vehicle distance RS between the host vehicle and the rear vehicle can be defined as a value that satisfies RS> RD-D (10).

In this way, in the processing from step 105 to step 108, the inter-vehicle distance F between the own vehicle and the front vehicle and the safe inter-vehicle distance FS between the own vehicle and the front vehicle are calculated from the processing from step 109 to step 112. Calculates the inter-vehicle distance R between the own vehicle and the rear vehicle and the safe inter-vehicle distance RS between the own vehicle and the rear vehicle in parallel, and proceeds to step 113.

In step 113, the speed limit VL, the cruising speed VC, the traveling speed V, the front inter-vehicle distance F, the front safe inter-vehicle distance FS, and the rear inter-vehicle distance R obtained in step 113 are obtained.
Also, the vehicle control determination means 13 determines the vehicle control using the rear safety inter-vehicle distance RS. FIG. 10 shows a flow of a series of processes in the vehicle control determination means 13. The vehicle control determination means 13 determines the positional relationship between the own vehicle and the front vehicle and the rear vehicle from the relationship between the front vehicle distance F and the rear vehicle distance R, and the positional relationship and the traveling speed V and cruising speed V of the vehicle.
Based on C, the safe inter-vehicle distance FS between the own vehicle and the front vehicle, and the safe inter-vehicle distance RS between the own vehicle and the rear vehicle, a determination regarding vehicle control is made. FIG. 20 is a diagram showing the positional relationship between the host vehicle, the front vehicle, and the rear vehicle. At this time, front inter-vehicle distance F, rear inter-vehicle distance R, front safe inter-vehicle distance F
Focusing on the relationship between S and the rear safety inter-vehicle distance RS, the relative positional relationship between the host vehicle, the front vehicle, and the rear vehicle is (1) the inter-vehicle distance with the front vehicle and the inter-vehicle distance with the rear vehicle are sufficient. (2) The vehicle distance to the vehicle ahead is sufficiently wide, but the vehicle distance to the vehicle behind is short (3) The vehicle distance to the vehicle behind is sufficiently wide, but the vehicle distance to the vehicle ahead is When the distance is short (4) The distance between the vehicle ahead and the vehicle behind can be divided into four areas.

In the case of (1), that is, step 8 in FIG.
In 01, if it is determined that (F ≧ FS) ∩ (R ≧ RS) (11), the process proceeds to step 802, and if not, the process proceeds to step 807. In step 802, it is determined whether the vehicle speed exceeds the cruise speed. If it is determined in steps 802 and 803 that the vehicle is traveling at a speed exceeding the cruising speed, step 80 is performed in order to decelerate to the cruising speed.
At -4, -1 is assigned to the vehicle control parameter CNT. On the contrary, if it is determined in step 802 that the cruise speed is not exceeded, 1 is substituted in the vehicle control parameter CNT in step 806 in order to accelerate to the cruise speed. If it is determined in step 803 that the vehicle is traveling at the cruise speed, the vehicle control parameter CNT is transmitted in step 805 in order to travel at the same speed.
Substitute 0 for.

In the case of (2), that is, when it is determined that (F ≧ FS) ∩ (R <RS) (12) in step 807, the process proceeds to step 808, and otherwise, the process proceeds to step 811. In step 808, it is determined whether or not the vehicle speed exceeds the cruise speed. When it is determined that the host vehicle is traveling at a speed equal to or higher than the cruising speed, the vehicle control parameter CNT is sent in step 809 in order to give a warning to the rear vehicle to decelerate and increase the inter-vehicle distance. Substitute 2 for. On the contrary, when it is determined that the vehicle is traveling at a speed that does not reach the cruising speed, 1 is substituted into the vehicle control parameter CNT in step 810 in order to accelerate the vehicle and increase the inter-vehicle distance to the rear vehicle.

In the case of (3), that is, when it is determined in step 811 that (F <FS) ∩ (R ≧ RS) (13), the vehicle is decelerated to increase the inter-vehicle distance to the vehicle ahead. , -1 is substituted in the vehicle control parameter CNT in step 812.

In the case of (4), that is, when it is determined in step 811 that (F <FS) ∩ (R <RS) (14), the vehicle can be accelerated to increase the inter-vehicle distance. It is also dangerous to slow down and widen the distance between you and the vehicle ahead. Therefore, in order to give a warning for decelerating the rear vehicle, 2 is substituted in the vehicle control parameter CNT in step 813.

The rear vehicle warning means 14 and the vehicle speed control means 15 are operated based on the judgment regarding the vehicle control performed as described above. If it is determined in step 114 of FIG. 3 that the vehicle control parameter CNT is set to 1, the process proceeds to step 115 and the vehicle speed control means 15 accelerates. When it is determined in step 116 that the vehicle control parameter CNT is set to -1, the process proceeds to step 117, and the vehicle speed control means 15 decelerates.
When it is determined in step 118 that CNT is set to 2, the process proceeds to step 119, and the rear vehicle warning means 1
A warning is issued to the vehicle behind from 4. If it is determined in step 118 that CNT is set to 0, the vehicle travels at a constant speed without changing the speed.

By repeating the above processing for each image given at a constant sampling interval, the relative position with respect to other vehicles existing in front of and behind the vehicle is taken into consideration while considering the speed limit on the road. According to the relationship,
Highly safe automatic speed control can be performed.

The second embodiment of the present invention will be described below with reference to the drawings. FIG. 21 is a block diagram showing the basic configuration of the second embodiment of the present invention. The basic configuration of the second embodiment is the same as the basic configuration of the first embodiment, except that a front inter-vehicle distance predicting means 16, a rear inter-vehicle distance predicting means 17, and a driver warning means 18 are added, and the vehicle control determining means 13 is further added.
Has been slightly modified. The front inter-vehicle distance predicting means 16 predicts the front inter-vehicle distance after one sampling interval based on the change rate of the front inter-vehicle distance F calculated by the front inter-vehicle distance calculating means 8. Similarly, the rear inter-vehicle distance predicting means 17 predicts the rear inter-vehicle distance after one sampling interval based on the rate of change of the rear inter-vehicle distance R calculated by the rear inter-vehicle distance calculating means 9. Further, the vehicle control determination means 13 has a front inter-vehicle distance F calculated by the front inter-vehicle distance calculation means 8, a rear inter-vehicle distance R calculated by the rear inter-vehicle distance calculation means 9,
Calculated by the traveling speed V detected by the vehicle speed detecting means 3, the speed limit VL on the traveling path set by the speed limit setting means 4, the cruising speed VC set by the cruising speed setting means 5, and the forward safe inter-vehicle distance calculating means 11. Safe vehicle distance FS between the own vehicle and the front vehicle, the safe vehicle distance RS between the own vehicle and the rear vehicle calculated by the rear safety vehicle distance calculating means 12, and the front vehicle distance predicting means 16
Based on the predicted value FP of the front inter-vehicle distance after one sampling interval calculated by and the predicted value RP of the rear inter-vehicle distance after one sampling interval calculated by the rear inter-vehicle distance predicting means 17, the determination regarding the vehicle control is performed. Further, in the driver warning means 18, the vehicle control determination means 13 recognizes a fallen object from the front vehicle, interruption of another vehicle before and after the own vehicle, rapid deceleration of the front vehicle, and rapid acceleration of the rear vehicle. In this case, a warning is given to the driver by voice or display of a warning lamp.

Next, the operation of the auto-cruise device according to the second embodiment of the present invention will be described with reference to the flow chart shown in FIG.

First, step 101 to step 104
Up to the above, the processing as described in the first embodiment is performed, and the process proceeds to step 901 and step 902. Step 901
Then, based on the change rate of the front inter-vehicle distance calculated in step 107, the front inter-vehicle distance after one sampling interval is predicted. FIG. 23 shows a flow of a series of processes in the front inter-vehicle distance predicting means 16. Step 100 of FIG.
In step 1, the value calculated from the current image and the value calculated from the image one sampling before are compared with respect to the front inter-vehicle distance calculated in step 107 of FIG. 22, and the amount of change is obtained. In step 1002, step 1001
A predicted value of the front inter-vehicle distance after one sampling interval is calculated on the basis of the change amount of the front inter-vehicle distance obtained in. That is, assuming that the change amount of the front inter-vehicle distance calculated in step 1001 is ΔF, the predicted value FP of the front inter-vehicle distance after one sampling interval is calculated by FP = F + ΔF (15).

Similar processing is performed for the rear vehicle. In step 902 of FIG. 22, the rear inter-vehicle distance after one sampling interval is predicted based on the change rate of the rear inter-vehicle distance calculated in step 111. FIG. 24 shows a flow of a series of processes in the rear inter-vehicle distance predicting means 17. In step 1101 of FIG. 24, step 111 of FIG.
Regarding the rear inter-vehicle distance calculated in step 1, the value calculated from the current image is compared with the value calculated from the image one sampling before, and the amount of change is obtained. In step 1102, a predicted value of the rear inter-vehicle distance after one sampling interval is calculated based on the amount of change in the rear inter-vehicle distance obtained in step 1101. That is, assuming that the change amount of the rear inter-vehicle distance calculated in step 1101 is ΔR, the predicted value RP of the rear inter-vehicle distance after one sampling interval is calculated by RP = R + ΔR (16).

In this way, steps 105 and 10 are performed.
6, 107, 108, 901, the inter-vehicle distance F between the host vehicle and the front vehicle, and the safe inter-vehicle distance F between the host vehicle and the front vehicle.
S and the predicted value FP of the front inter-vehicle distance after one sampling interval are calculated as steps 109, 110, 111, 112, 9
In the process of 02, the inter-vehicle distance R between the host vehicle and the rear vehicle, the safe inter-vehicle distance RS between the own vehicle and the rear vehicle, and the predicted value of the rear inter-vehicle distance after one sampling interval are calculated, and the process proceeds to step 903.

In step 903, the speed limit VL, the cruising speed VC, the traveling speed V, the front inter-vehicle distance F, the front safe inter-vehicle distance FS, the rear inter-vehicle distance R, which are obtained as described above, are obtained.
The vehicle control determination means 13 determines the vehicle control using the rear safety inter-vehicle distance RS, the front inter-vehicle distance predicted value FP, and the rear inter-vehicle distance predicted value RP.

FIG. 25 shows a flow of a series of processes in the vehicle control judging means 13. In order to reduce the processing time, the processing from step 1201 to step 1203 and the processing from step 1204 to step 1206 can be processed in parallel by using different processors.

First, at step 1201, the front inter-vehicle distance F actually calculated by the front inter-vehicle distance calculating means 8 is compared with the predicted value FP predicted by the front inter-vehicle distance predicting means 16. At this time, it is determined that F <FP-C (C is a constant indicating the error range of the predicted value) (17) is determined because a fallen object from the preceding vehicle ahead of the own vehicle, an interruption of another vehicle, a preceding vehicle This is the case when a rapid deceleration of is recognized. Therefore, in this case, in order to give a warning of the forward warning to the driver, step 1202
Then, 1 is set to the front warning warning parameter FWG. On the other hand, when it is determined in step 1201 that F ≧ FP−C (C is a constant indicating the error range of the predicted value) (18), 0 is set in the parameter FWG in step 1203.

At step 1204, the rear inter-vehicle distance R actually calculated by the rear inter-vehicle distance calculating means 9 is compared with the predicted value RP predicted by the rear inter-vehicle distance predicting means 17. At this time, it is determined that R <RP-C (C is a constant indicating the error range of the predicted value) (19) because the interruption of another vehicle behind the own vehicle and the rapid acceleration of the vehicle behind the vehicle are determined. When it is admitted. In this case, in order to give a rearward warning to the driver, 1 is set in the rearward warning parameter RWG in step 1205. On the other hand, when it is determined in step 1204 that R ≧ RP−C (C is a constant indicating the error range of the predicted value) (20), 0 is set in the parameter RWG in step 1206.

In this way, the front caution warning parameter FWG is set in the processing from step 1201 to step 1203, and the rear caution warning parameter RWG is set in the processing from step 1204 to step 1206, and then step 801 is performed. Go to.

From step 801 to step 813, the processing as described in the first embodiment is performed, and the process proceeds to step 904 and step 906 in FIG.

In step 904 of FIG. 22, step 90 is executed.
Based on the processing in 3, it is determined whether or not to give a warning of the forward warning to the driver. When it is determined in step 904 that FWG = 1 (21), the process proceeds to step 905, and the driver warning means 18 gives the driver a warning of attention to the front.

In step 906, step 903 is executed.
Based on the processing in step 1, it is determined whether or not to give a warning of backward warning to the driver. When it is determined in step 906 that RWG = 1 (22), the process proceeds to step 907, and the driver warning means 18 gives a warning of backward caution to the driver.

In this way, after performing the processing from step 904 to step 905 and the processing from step 906 to step 907 respectively, step 11
Go to 4.

The processing from step 114 to step 119 is as described in the first embodiment.

By repeatedly performing the above-described processing on each image given at a constant sampling interval, a falling object from a vehicle ahead, a sudden deceleration of a vehicle ahead, a sudden acceleration of a vehicle behind, a front vehicle front and rear Highly safe automatic speed control can be performed while warning the driver of a dangerous situation such as interruption of another vehicle. In the first and second embodiments of the present invention, it is assumed that the driver inputs the speed limit setting means by using the ten-key pad. This is because the speed limit is recognized from the road sign and the road display by image processing. Can be done and automatically input, or by combining with a navigation system,
The speed limit may be recognized from the road information written in the map data. Further, the inter-vehicle distance calculating means is obtained from the correspondence between the scanning line and the distance on the road, but two cameras are installed in front of and behind the vehicle at regular intervals in the vehicle width direction to obtain a stereo image. A stereoscopic method for performing three-dimensional distance measurement may be used, or a Doppler radar device, a laser radar device, or the like may be used.

[0060]

As described above, according to the present invention, not only the inter-vehicle distance to the other vehicle in front, but also the relative positional relationship to the other vehicle in the rear is taken into consideration, so that the rear vehicle is close to the vehicle. In such a situation, the automatic speed control with high safety can be performed because the vehicle does not suddenly decelerate even when the inter-vehicle distance from the vehicle ahead is narrowed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of mounting a camera on a vehicle.

FIG. 3 is a flowchart showing the operation of the first embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the speed limit input means.

FIG. 5 is a flowchart showing the operation of the cruise speed setting means.

FIG. 6 is a flowchart showing the operation of a front vehicle recognition means.

FIG. 7 is a flowchart showing an operation of a rear vehicle recognition means.

FIG. 8 is a flowchart showing the operation of a front safety inter-vehicle distance calculating means.

FIG. 9 is a flowchart showing the operation of the rear safety inter-vehicle distance calculating means.

FIG. 10 is a flowchart showing the operation of the vehicle control determination means in the first embodiment.

FIG. 11: Input image

12 is a diagram showing an image in which edges are extracted from the input image in FIG.

13 is a diagram showing an image in which a white line is detected from the edge image of FIG.

FIG. 14 is a diagram showing an image in which a road area is limited based on the image in FIG.

FIG. 15 is a diagram showing an image showing a front vehicle recognized in the road region shown in FIG. 14;

FIG. 16 is a diagram showing an XY coordinate system.

FIG. 17 is a diagram showing a θ-ρ coordinate system.

FIG. 18 is a diagram showing a relationship between an inter-vehicle distance and a braking stop distance in the own vehicle and the preceding vehicle.

FIG. 19 is a diagram showing a relationship between an inter-vehicle distance and a braking stop distance in the own vehicle and the rear vehicle.

FIG. 20 is a diagram showing a positional relationship between a host vehicle, a front vehicle, and a rear vehicle.

FIG. 21 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 22 is a flowchart showing the operation of the second embodiment of the present invention.

FIG. 23 is a flowchart showing the operation of the front inter-vehicle distance predicting means.

FIG. 24 is a flowchart showing the operation of the rear inter-vehicle distance predicting means.

FIG. 25 is a flowchart showing the operation of the vehicle control determination means in the second embodiment.

[Explanation of symbols]

 1 front image pickup means 2 rear image pickup means 3 vehicle speed detection means 4 speed limit input means 5 cruising speed setting means 6 front vehicle recognition means 7 rear vehicle recognition means 8 front inter-vehicle distance calculation means 9 rear inter-vehicle distance calculation means 10 braking stop distance storage means 11 front safe inter-vehicle distance calculating means 12 rear safe inter-vehicle distance calculating means 13 vehicle control determining means 14 rear vehicle warning means 15 vehicle speed control means 16 front inter-vehicle distance predicting means 17 rear inter-vehicle distance predicting means 18 driver warning means

Claims (2)

[Claims] 1. A front image pickup means mounted on a vehicle for front shooting, a rear image pickup means for rear shooting, a vehicle speed detection means for detecting a vehicle speed, and a speed limit setting means for setting a speed limit on a traveling road. A cruising speed setting means for setting a cruising speed, a front vehicle recognizing means for recognizing a front vehicle from an image captured by the front imaging means, and a rear vehicle recognition for an image captured by the rear imaging means. A rear vehicle recognizing means, a front inter-vehicle distance calculating means for calculating an inter-vehicle distance between the front vehicle and the own vehicle recognized by the front vehicle recognizing means, and a rear vehicle and the own vehicle recognized by the rear vehicle recognizing means. The vehicle-to-vehicle distance calculation means for calculating the vehicle-to-vehicle distance, the braking-stop-distance storage means for storing the braking-stop distance according to the traveling speed of the vehicle, and the front-vehicle distance calculation means. Forward safety for calculating a safe inter-vehicle distance between the own vehicle and the front vehicle from the calculated front inter-vehicle distance, the own vehicle speed detected by the vehicle speed detection means, and the braking stop distance stored in the braking stop distance storage means. From the inter-vehicle distance calculation means, the rear inter-vehicle distance calculated by the rear inter-vehicle distance calculation means, the own vehicle speed detected by the vehicle speed detection means, and the braking stop distance stored in the braking stop distance storage means, the own vehicle A rear safe inter-vehicle distance calculating means for calculating a safe inter-vehicle distance between a vehicle and a rear vehicle, a front inter-vehicle distance calculated by the front inter-vehicle distance calculating means, and a rear inter-vehicle distance calculated by the rear inter-vehicle distance calculating means and the vehicle speed detection. Own vehicle speed detected by means, speed limit set by the speed limit setting means, and cruise speed set by the cruise speed setting means And vehicle control determination means for determining vehicle control of the own vehicle from the front safety inter-vehicle distance calculated by the front safety inter-vehicle distance calculation means and the rear safety inter-vehicle distance calculated by the rear safety inter-vehicle distance calculation means, Rear vehicle warning means for issuing a warning to the rear vehicle based on the judgment by the vehicle control judgment means,
An auto cruise device comprising a vehicle speed control means for controlling the speed of the host vehicle based on the judgment by the vehicle control judgment means. 2. The front inter-vehicle distance predicting means for predicting the front inter-vehicle distance after one sampling interval based on the change rate of the front inter-vehicle distance calculated by the front inter-vehicle distance calculating means, and the rear inter-vehicle distance calculating means. Based on the change rate of the rear inter-vehicle distance, the rear inter-vehicle distance predicting means for predicting the rear inter-vehicle distance after one sampling interval, and the driver warning means for warning the driver based on the judgment by the vehicle control judging means The vehicle control determination means includes the front vehicle distance calculated by the front vehicle distance calculation means, the rear vehicle distance calculated by the rear vehicle distance calculation means, and the own vehicle speed and the speed limit setting detected by the vehicle speed detection means. Speed limit set by the means and cruise speed set by the cruise speed setting means and front safe inter-vehicle distance calculated by the front safe inter-vehicle distance calculation means And a backward safety inter-vehicle distance calculated by the rear safety inter-vehicle distance calculating means, a predicted value of the front inter-vehicle distance predicted by the front inter-vehicle distance predicting means, and a predicted value of the rear inter-vehicle distance predicted by the rear inter-vehicle distance predicting means. The auto cruise apparatus according to claim 1, wherein the vehicle control of the host vehicle is judged from the vehicle.