JPH11160078A - System for estimating condition of traveling road - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable estimation of curved shape of a traveling road in a wide range ahead of a vehicle even under adverse conditions such as rain and fog, by estimating condition of a road ahead to travel on the basis of specific information obtained from design conditions of a traveling road ahead of one's own vehicle. SOLUTION: A device for estimating condition of a traveling road is provided with a control device 10 to estimate the condition of the traveling road such as a radius of curvature at each location within a predetermined distance ahead of one's own vehicle on the basis of detection signals from a yaw rate sensor 11 and a wheel velocity sensor 12, image pickup signals of road white lines from a camera 13, map information from a navigation device 20. Then, for example, when a vehicle enters a curve from a straight-ahead zone, it is determined that the vehicle is traveling, for example, in an entrance transition zone on the basis of a measured radius of curvature at a present location of traveling and information on the condition of the travelling road from map data, etc., to obtain specific information of the traveling road such as the parameter of a clothoid curve. On the basis of the specific information, the condition of the road ahead is estimated and set in a register 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel lane estimating apparatus which can be applied to a system for preventing a lane from deviating from a traveling lane, a system for detecting a preceding vehicle in the same lane, and more particularly to a traveling road shape estimating apparatus. The present invention relates to a traveling road shape estimating device for estimating a curved shape of a road.

[0002]

2. Description of the Related Art Conventionally, in a device for estimating a curved shape of a traveling road in front of a vehicle, for example, a white line drawn as a boundary of a traveling lane in front of the vehicle is photographed by an imaging device (camera) and an image obtained is obtained. The geometric shape of the white line is calculated from the information. Then, the curved shape (curvature, radius of curvature, and the like) of the travel path is further estimated from the geometric shape of the white line (see, for example, JP-A-3-139706).

[0003]

In the conventional apparatus for estimating the curved shape of the traveling road ahead of the vehicle as described above, since the white line in front of the vehicle must be photographed by the imaging device, rain, fog, etc. Under such a bad environment, it is difficult to recognize a white line from image information obtained by an imaging device. In addition, when trying to widen the range (vehicle forward distance) for estimating the curved shape of the traveling road, a white line distant from the vehicle must be photographed, and when night driving is considered, distant areas can be illuminated. This lighting device must be mounted on the vehicle, which is not very realistic.

[0004] Therefore, an object of the present invention is to provide a camera which can be used even under bad conditions such as rain and fog, without photographing a distant place.
An object of the present invention is to provide a travel path shape estimating device that can estimate a curved shape of a travel path in a relatively wide range in front of a vehicle.

[0005]

According to a first aspect of the present invention, there is provided a travel path shape estimating apparatus for detecting a traveling position of a host vehicle. A unique information detecting means for detecting unique information determined from design conditions of a traveling path ahead of the position detected by the position detecting means; and a position detecting means based on the unique information detected by the unique information detecting means. An estimating means for calculating information representing the shape of the traveling road ahead of the detected position.

[0006] Main roads are constructed in accordance with predetermined design conditions in consideration of ease of vehicle operation and the like. For example, the design conditions are such that the radius of curvature of a curved road gradually decreases, then a constant radius of curvature (minimum radius of curvature) continues for a while, and then the radius of curvature gradually increases to continue on a straight road. It is built in accordance with the (design standard) (there may be no part with a constant radius of curvature). The part where the radius of curvature gradually decreases is called, for example, an entrance relaxation section, and the part where the curvature radius gradually increases is called, for example, an exit relaxation section.

[0007] The road shapes of the entrance mitigation section and the exit mitigation section as described above are designed to approximate, for example, a predetermined curve. The approximate curve is unique information (specific information)
Can be specified. The road shape of a section having a constant radius of curvature can be specified by information (specific information) indicating the degree of curve of the traveling path such as the radius of curvature (curvature).

In such a situation, in the traveling road shape estimating apparatus according to the present invention, when the position detecting means detects the traveling position of the own vehicle, the unique information determined from the design conditions of the traveling road ahead of the detected position is detected. Then, based on the unique information, information representing the shape of the traveling road ahead of the detection position is calculated. Then, the calculation result is provided as information representing the estimated shape of the traveling road from the traveling road shape estimation device to another system (for example, a system for detecting a preceding vehicle, a traveling lane departure prevention system).

As the information representing the shape of the travel path, a curvature, a radius of curvature, or the like representing a degree of bending at each point on the travel path can be used. The unique information determined from the design conditions of the travel path can be calculated from the shape of the travel path actually detected, or can be calculated from the shape of the travel path included in the map information.

As described above, from the viewpoint of calculating the unique information determined from the design conditions of the traveling road from the shape of the actually detected traveling road, the present invention provides the above-described invention. In the travel path shape estimating device, the unique information detection means includes a shape detection means for detecting a shape of the travel path at the travel position detected by the position detection means, and a travel position and a shape detected by the position detection means. It is possible to provide a unique information calculating means for calculating the unique information based on the shape of the traveling road detected by the detecting means.

From the viewpoint of obtaining the unique information from the map information, the present invention provides the travel path shape estimating device, wherein the unique information detecting means includes a position detecting means. And a unique information calculation means for calculating the unique information based on the shape of the travel path obtained from the map information including the travel path ahead of the position detected by the above.

The map information can be stored in a storage device mounted on the host vehicle. It is also possible to receive the provision of map information from outside by wireless or the like. When estimating the shape of a curved road, in a vehicle traveling on a straight road following the curved road, the shape of the existing curved road cannot be estimated from the actually detected road shape (linear shape). . Further, it is difficult to obtain map information that can accurately grasp the shape of each traveling path.

Therefore, from the viewpoint that the current running position of the vehicle can be calculated more accurately on the inside and outside of a curved road, the running road shape estimating apparatus according to the present invention is characterized in that As described, position detecting means for detecting the running position of the vehicle, and determining means for determining whether the running position detected by the position detecting means is a straight road portion or a curved road portion, When the determination unit determines that the road is a straight road portion, based on the design condition of the travel road based on the shape of the travel road obtained from the map information including the travel road ahead of the position detected by the position detection unit. First unique information calculating means for calculating unique information determined by the first unique information calculating means, and a curved road portion ahead of the position detected by the position detecting means based on the unique information obtained by the first unique information calculating means. Information representing the shape First estimating calculating means for calculating, shape detecting means for detecting the shape of the traveling road at the traveling position detected by the position detecting means when the determining means determines that the vehicle is on a curved road portion; A second unique information calculation means for calculating unique information determined based on the design conditions of the travel path based on the travel position detected by the means and the shape of the travel path detected by the shape detection means, A second estimating means for calculating information representing the shape of the traveling road ahead of the position detected by the position detecting means based on the unique information obtained by the second unique information calculating means. Can be configured.

In such a travel path shape estimating apparatus, when it is detected that the own vehicle is present on the straight road portion before the curved road portion, the travel road (own vehicle) is determined based on the shape of the travel road obtained from the map information. (It may include a curved road existing ahead of the traveling position of the vehicle). Therefore, even when the vehicle is traveling on a straight road portion, it is possible to estimate the shape of the curved road portion existing ahead of the current traveling position based on the unique information.

When it is detected that the vehicle is present on a curved road portion, unique information of the traveling road is calculated based on the actually detected shape of the traveling road. Since the specific information is calculated based on the actually detected shape of the traveling path, more accurate specific information can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration example of a traveling road shape estimation device according to an embodiment of the present invention. A detection signal corresponding to the vehicle yaw rate from the yaw rate sensor 11 and a wheel speed pulse synchronized with the rotation of the wheel from the wheel speed sensor 12 are respectively supplied to the control device (ECU) 1
0 is provided. The camera 13 is mounted on the vehicle so that a white line that defines a driving lane near the vehicle can be photographed.
Are provided. DGPS (Differential Global Po
traveling position information of the vehicle from the sitioning system 21,
For example, the navigation device 20 is provided with the map information from the map information reading unit 22 that reads the map information stored in a recording medium such as a CD-ROM. The navigation system 20 provides the control device 10 with map information on a traveling path ahead of the vehicle and traveling position information detected by the DGPS 21.

The control device 10 controls the yaw rate sensor 1
Based on the detection signal from the vehicle speed sensor 1 and the wheel speed sensor 12, and the map information from the navigation device 20, a process of estimating the shape of the traveling road within a predetermined distance in front of the own vehicle is performed. Then, the shape of the traveling path obtained as a result of the processing, for example,
The radius of curvature of the travel path at each point within the predetermined distance is set in the register 14.

For example, as shown in FIG. 2, it is assumed that a vehicle V enters a curved road from a straight traveling section Ss and travels further from the curved road to a straight traveling section. This curved road generally has an entrance relaxation section Si in which the radius of curvature Ri changes so as to gradually decrease from the straight section Ss, a constant curvature section Sc having a constant radius of curvature (minimum radius of curvature) Rm, and a radius of curvature Ro. Is designed to be composed of an exit relaxation section So following a straight traveling section that gradually increases (there may be no constant curvature section Sc).

The shapes of the entrance relaxation section Si and the exit relaxation section So are designed to be approximated by, for example, a clothoid curve. In this case, in the entrance relaxation section Si, the relationship between the distance Li from the entry point Pi and the curvature radius Ri at the point of the distance Li is described by Ai ² = Ri × Li. In the exit relaxation section So, the relationship between the distance Lo from the exit point Po and the radius of curvature Ro at the point of the distance Lo is described as Ao ² = Ro × Lo. In the above equations, Ai and Ao are the parameters of the clothoid curve.
o is the entrance relaxation section Si and the exit relaxation section S, respectively.
This is unique information that specifies the shape of the traveling road at o. Hereinafter, each parameter Ai, Ao is called a relaxation parameter.

The shape of the traveling road in the constant curvature section Sc is specified by the radius of curvature Rm (minimum radius of curvature) of the traveling road. In the vehicle V traveling on the traveling path as described above (see FIG. 2), the control device 10 may be configured as shown in FIGS.
The processing for estimating the shape of the traveling road is executed according to the procedure shown in FIG.

First, in FIG. 3, map data and current position information (DGPS 21
When (S1, S2) is obtained (S1, S2), an estimation calculation of the traveling position of the vehicle V on the traveling path obtained from the map data is performed (S3). Further, the shape of the traveling road ahead of the vehicle V obtained from the map data is calculated (S4). Specifically, when there is a curved road, the minimum radius of curvature Rm of the curved road and the total length L1 of the curved road are calculated.

On the other hand, the distance (lateral position of the white line) between the white line and the own vehicle V is calculated based on the image pickup signal from the camera 13 (S11), and the attitude of the vehicle V with respect to the white line is calculated based on the calculation result. (S14). Further, the yaw angle of the vehicle is detected from the detection signal from the yaw rate sensor 11 (S12), and the running distance is calculated based on the wheel speed pulse from the wheel speed sensor 12 (S13). The travel locus of the vehicle is calculated based on the yaw angle and the travel distance (S15). Then, the shape of the white line is calculated based on the attitude and the traveling locus of the vehicle V with respect to the white line (S1).
6) Further, the radius of curvature Rn of the traveling road is calculated (S1).
7). The specific processing in steps S11 to S17 has already been proposed by the present applicant in Japanese Patent Application No. 9-132563.

The curvature radius Rn at the current traveling position of the vehicle V calculated as described above, the estimated position on the traveling road and the information on the road shape obtained from the map data (the minimum radius of curvature of the curved road, etc.) ), It is determined which section the vehicle V is traveling in (S20). For example, when the obtained radius of curvature Rn is very large, it is determined that the section is a straight section Ss. It is determined as the relaxation section Si. Further, when the obtained radius of curvature Rn is substantially equal to the minimum radius of curvature Rm (Rn = Rm), it is determined to be a constant curvature section Sc, and the radius of curvature Rn obtained in the process of increasing the radius of curvature is smaller than the minimum curvature radius Rm If it is larger (Rn> Rm), it is determined to be the exit relaxation section So.

When it is determined that the vehicle V is traveling in the straight section Ss, no processing for obtaining information relating to the road shape is performed. In FIG. 3, P100
Is indicated by a broken line, this process P100 is not particularly executed in this embodiment. Vehicle V goes straight section S
s, the vehicle V is determined to be traveling in the entrance relaxation section Si, and when it is determined that the vehicle V is traveling in the entrance relaxation section Si, the distance Li from the entry point Pi of the curved road to the current traveling position is estimated, and , The relaxation parameter A of the inlet relaxation section Si
Calculation of i and estimation of the relaxation parameter Ao of the exit relaxation section So are performed (S21). Specifically, the distance Li from the entry point Pi of the curved road to the current traveling position is estimated based on the obtained current traveling position information (data from the DGPS 21) and the map information. The relaxation parameter Ai is calculated according to Ai = (Ri × Li) ^1/2 using the radius of curvature Rn (step S17) obtained in the step ( ¹ ). Further, the relaxation parameter A in the exit relaxation section So is set as a value equal to the relaxation parameter Ai.
o is estimated.

After that, the length L2 of the entrance relaxation section Si, the length L3 of the exit relaxation section So, and the length L4 of the constant curvature section Sc are estimated (S22). Specifically, since the entrance relaxation section Si is in contact with the constant curvature section Ss, the distance from the entry point P1 to the constant curvature section Ss is the length L2 of the entrance relaxation section Si, and the length of the entrance relaxation section Si is L
2 is estimated as L2 = Ai ² / Rm based on the relaxation parameter Ai and the minimum radius of curvature Rm in the constant curvature section Sc. Similarly, the exit point P of the curved road
The length L3 of the exit relaxation section So, which is the distance from o to the constant curvature section Sc, is the estimated Ao and the minimum curvature radius R.
It is estimated as based on m Metropolitan L3 = Ao ² / Rm. Further, using the length L1 of the entire curve road obtained from the map information and the lengths L2 and L3 of the entrance relaxation section Si and the exit relaxation section So estimated as described above, the length of the constant curvature section Sc is obtained. L4 is estimated as L4 = L1-L2-L3.

As described above, the length L of the entrance relaxation section Si
2. The length L4 of the constant curvature section Sc and the exit relaxation section So
When the length L3 is estimated, step S30 shown in FIG.
Move to the processing of. In FIG. 4, first, a curvature radius estimation point Pn ahead of the current traveling point is determined (S3).
0). In this case, the estimation interval is predetermined, and the curvature radius estimation point Pn is determined based on the detected current traveling position of the vehicle V and the estimation interval. Then, it is determined in which section of the curved road the determined curvature radius estimation point Pn is located based on the lengths L2, L3, L4 of the sections estimated as described above (S3).
1).

When it is determined that the curvature radius estimation point Pn is within the entrance relaxation section Si, the distance Li between the point Pn and the approach point Pi and the relaxation parameter Ai calculated as described above (FIG. Using 3 steps S21),
The curvature radius Rf at the point Pn is calculated according to Rf = Ai ² / Li (S33).

If it is determined that the curvature radius estimation point Pn is in the constant relaxation section Sc, the curvature radius Rf at the curvature radius estimation point Pn is determined as the minimum curvature radius Rm (S34). Further, when it is determined that the curvature radius estimation point Pn is within the exit relaxation section So, the distance Li from the exit point Po of the curved road to the curvature radius estimation point Pn and the relaxation parameter Ao estimated as described above. with bets, the radius of curvature Rf at that point Pn is calculated in accordance with ^{Rf = Ao 2 / Lo (S35} ).

Further, when it is determined that the curvature radius estimation point Pn is a straight section following the exit point Po of the curved road, the curvature radius Rf at the point Pn is determined to be infinite (無限) ( S32). As described above, when the calculation of the radius of curvature Rf at the point Pn according to the section to which the radius of curvature estimation point Pn belongs ends, the system proceeds to the point Pn ahead.
It is recognized that the estimation of the radius of curvature Rf at n has been completed (S
36), it is determined whether the estimation of the radius of curvature of the traveling road in the predetermined estimation range ahead of the vehicle V has been completed (S3).
7). If it is determined that the estimation of the radius of curvature of the traveling road within the estimation range has not been completed yet (S37), the next estimation is performed based on the radius of curvature estimation point Pn which has been the object of the radius of curvature estimation and the estimation interval. Radius of curvature estimation point Pn +
1 is determined (S30). Then, the curvature radius at the point Pn + 1 is estimated according to the section to which the curvature radius estimation point Pn + 1 belongs (S32, S32).
33, S34, S35).

The above processing is performed at the curvature radius estimation point P
It is repeatedly executed until n + i reaches the end of the predetermined estimation range ahead of the vehicle V. If it is determined that the processing in the estimation range is completed (S37, YES), the estimated radius of curvature Rf and the estimated point Pn are associated with each other and registered in the register 14 as data representing the road shape ahead. (See FIG. 1).

When the processing up to this point (FIGS. 3 and 4) is completed, the processing returns to the processing shown in FIG.
While traveling on i, the same processing is repeatedly performed.
As a result, the data representing the shape of the road ahead stored in the register 14 is sequentially updated. In the course of the processing that is repeatedly performed as described above, in step S21, the average value of the relaxation parameter Ai calculated so far and the average value of the relaxation parameter Ai calculated this time may be calculated as the final relaxation parameter Ai. it can.

While performing the above-described processing, the vehicle V enters the constant curvature section Sc (see FIG. 2).
In (see FIG. 3), when it is determined that the vehicle V is traveling in the constant curvature section Sc, the length L3 of the exit relaxation section So and the length L4 of the constant curvature section Sc are estimated (S23). Specifically, the relaxation parameter Ai ｛= (Rm × Li) based on the minimum curvature radius Rm detected by entering the constant curvature section Sc and the length L2 of the entrance relaxation section Si actually determined from the traveling distance. ) ^1/2} is calculated, at the same by using the relaxation parameters Ao and minimum curvature radius Rm of the same value, the length L3 of the outlet relaxation section So is estimated in accordance with L3 = Ai ² / Rm. Also, a curve obtained from the map information (S4) and the length L2 of the entrance relaxation section Si determined from the actual traveling distance as described above, the length L3 of the exit relaxation section So estimated as described above, and the map information. Using the total length L1 of the road, the length L4 of the constant curvature section Sc is estimated according to L4 = L1-L2-L3.

As described above, the length L of the exit relaxation section So
3 and the length L4 of the constant curvature section Sc are estimated, as described above, the road shape information ahead of the vehicle V traveling in the constant curvature section Sc is estimated according to the procedure shown in FIG. . In this case, since the vehicle V is traveling in the constant curvature section Sc, the curvature radius estimation point Pn is in the constant curvature section S.
c, a straight section following the exit relaxation section So and the exit point Po of the curved road. Therefore, the curvature radius Rf at each point is calculated by the processing in steps S34, S35, and S32 corresponding to each section.

Then, the calculated curvature radius Rf and the corresponding curvature estimation point Pn are set in the register 14 as data representing the shape of the road ahead (S38). And
While the vehicle V is traveling in the constant curvature section Sc, the same processing is repeated, and the content of the register 14 is updated to data representing the shape of the front road obtained each time. Further, when the vehicle V enters the exit relaxation section So from the constant curvature section Sc and it is determined in step S20 (see FIG. 3) that the vehicle V is traveling in the exit relaxation section So, the current traveling position is determined. Lo between the road and the exit point Po of the curved road is estimated, and the relaxation parameter Ao of the exit relaxation section So is estimated.
Is calculated. Specifically, the distance Lo to the exit point Po of the vehicle V is estimated based on the detected current position of the vehicle V and the position of the exit point Po on the curved road obtained from the map information. Further, using the detected radius of curvature Rn at the current traveling position (step S17) and the estimated distance Lo from the current traveling position to the exit point Po of the curved road,
The relaxation parameter Ao of the exit relaxation section So is estimated according to Ao = (Rn × Lo) ^1/2 .

As described above, when the distance Lo from the traveling position of the vehicle V to the exit point Po of the curved road and the relaxation parameter Ao of the exit relaxation section So are estimated, as described above,
Road shape information ahead of the vehicle V is estimated according to the procedure of FIG. In this case, since the vehicle V is traveling in the exit relaxation section So, the curvature radius estimation point Pn is either the exit relaxation section So or the straight section following the exit point Po of the curved road. Accordingly, for each section, the radius of curvature R at each point is obtained by the processing in steps 35 and S32.
f is calculated.

Then, the calculated radius of curvature Rf and the corresponding estimated radius of curvature Pn are set in the register 14 as data representing the shape of the road ahead (S38). Then, while the vehicle V is traveling in the exit relaxation section So, the same processing is repeated, and the content of the register 14 is updated to data representing the shape of the front road obtained each time. As described above, data representing the shape of the road ahead of the vehicle V set in the register 14 (the radius of curvature Rf and the point thereof).
Is supplied to other systems such as a system for detecting a vehicle ahead and a system for preventing a lane departure.

In the above-described example, the road shape in front of the vehicle V (the radius of curvature at each point) is determined based on the actually detected radius of curvature Rn of the curved road (step S17 in FIG. 3).
Is estimated. Accordingly, the shape of the road ahead cannot be substantially estimated until the vehicle V actually enters the curved road (the entrance relaxation section Si). To solve this, the following processing can be performed.

That is, in the process of FIG. 3, when it is determined that the vehicle V is traveling in the straight section Ss just before entering the curved road (S20), a process P100 of an estimation calculation using map data is executed. You. This processing P100
For example, it is executed according to the procedure shown in FIG. In FIG. 5, a distance L5 from the current traveling position of the vehicle V to the entry point Pi of the curved road is estimated based on the current position information and the map information from the navigation device 20 (S26).
Then, based on the distance L5, it is determined whether or not a curved road exists within the above-described estimated range ahead of the vehicle V (S27). If it is determined that a curved road exists within the estimation range, the relaxation parameters Ai and Ao of the entrance relaxation section Si and the exit relaxation section So are estimated based on the map data from the navigation device 20 (S2).
8). As described above, when the respective relaxation parameters Ai and Ao are estimated, the entrance relaxation section S is calculated using the relaxation parameters Ai and Ao in the same manner as the above-described processing.
i length L2 (= Ai ² / Rm), exit relaxation section So length L3 (= Ao ² / Rm) and constant curvature section L4 (=
L1-L2-L3) is estimated (S29).

Here, the relaxation parameter of the entrance relaxation section Si
Ai is estimated, for example, according to the procedure shown in FIG.
You. In FIG. 6, first, from the navigation device 20
The road data ahead is read (S281), and
The traveling position of the host vehicle V is detected (S282). Above road
The road data is, for example, as shown in FIG.
Is represented by the coordinates Then, the detected travel of the own vehicle is performed.
Based on the row position, the forward road data is
It is converted (S283). Then, three points on the road
P_i-1, P_i, P_{i + 1}From the coordinate data of point P_iCurvature at
Radius R_iIs calculated (S284). This point P _iCurvature at
Radius R_iIs calculated as follows:

Each point P _i−1 , P _i , P _{i + 1 on the road} is defined, for example, as shown in FIG.
−y) is converted to p _i−1 , p _i , p _{i + 1} . In this _{case, (x i-1 -x)} 2 + (y i-1 -y) 2 = R 2 (1) (x i -x) 2 + (y i -y) 2 = R 2 (2) ( x _{i + 1} −x) ² + (y _{i + 1} −y) ² = R ² (3) Then, coordinate conversion as shown in FIG. 8B is performed. That is, A = x _{i + 1} −x _i−1 , C = y _{i + 1} −y _i−1, B = x _i −x _i−1 , D = y _i −y _i−1, and the above equation ( 1), (2), and (3) are (AX) ² + (CY) ² = R ^{2, that} is, A ² -2AX + X ² + C ² -2CY + Y ² = R ² (1) ′ (BX) ) ² + (DY) ² = R ^{2, that} is, B ² -2BX + X ² + D ² -2DY + Y ² = R ² (2) ′ X ² + Y ² = R ² (3) ′

By subtracting equation (3) 'from equation (1)', A ² -2AX + C ² -2CY = 0 (4) is obtained. By subtracting equation (3) 'from equation (2)', , B ² -2BX + D ² -2DY = 0 (5).

[0042] (4) D- (5) Clearing the Y by ^{C, A 2 D-2ADX +} C 2 D-2CDY = 0 B 2 C-2BCX + D 2 C-2DCY = 0 X = (A 2 D-B 2 C + C X is calculated as ^{2 D-D 2 C) /} (2 (AD-BC)) (6).

(4) When X is erased by B- (5) A, A ² B-2ABX + C ² B-2CBY = 0 B ² A-2BAX + D ² A-2DAY = 0 Y = (A ² BB Y is calculated as follows: ² A + C ² BD ² A) / (2 (CB−DA)) (7)

Then, R _i is calculated from X and Y according to R _i = (X ² + Y ² ) ^1/2 . If these three points P _i−1 , P _i and P _{i + 1} are points on the transition curve, R _i is regarded as the radius of curvature at the point P _i . The radius of curvature R _i at each point P _i as described above is calculated, to determine the inlet relaxation interval Si on the basis of the R _i (S285). Specifically, the radius of curvature R _i is infinite origin of the P _i that has changed to a finite value from (straight) inlet relaxation interval P _o (corresponding to the entry point Pi of the curve path of FIG. 2). The point at which the radius of curvature R _i becomes the minimum value is defined as the end point P _n of the entrance relaxation section Si.

When the entrance relaxation section Si is determined as described above, the relaxation parameter A _i is calculated using the curvature radius R _i corresponding to each point P _i in the entrance relaxation section Si (S286). Specifically, the calculated distance L _i from the origin P _o to the point P _i is in accordance with _{L i = (P o P 1} + P 1 P 2 + ... + P i-1 P i), and the distance L _i relaxation parameter a _i is calculated according to _{a i = (R i L i} ) 1/2 by using the curvature radius R _i at the point P _i.

As described above, the radius of curvature R at each point P _i
When the relaxation parameters A _i are calculated on the basis of _i , the average value thereof is calculated as the relaxation parameter A of the entrance relaxation section Ai.
It is calculated as i (S287). Ai = Σ (A _i ) / n (i = 1 to n) The relaxation parameter Ao of the exit relaxation section can be estimated by the same method as the relaxation parameter Ai of the entrance relaxation section.

As described above, each relaxation parameter Ai and A
When o is estimated, forward road estimation is performed in the same manner as described above based on the relaxation parameters Ai and Ao. In the procedure shown in FIG. 6 as described above, relaxation parameters A _i and is calculated from the radius of curvature R _i of the points P _i, relaxation parameters A _i based on the road tangentially theta _i of the points P _i
Can also be calculated.

In this case, the processing is executed according to the procedure shown in FIG. In FIG. 9, the same steps as those in FIG. 6 are denoted by the same reference numerals. In the procedure shown in FIG. 9, the calculation of the tangential direction θ _i (S284
a), determination of the relaxation period (S285a), the process of the computer (S286a) of the relaxation parameter A _i is different from the processing shown in FIG. Hereinafter, these processes will be described.

In this case, it is assumed that forward road data as shown in FIG. 10 has been obtained. Tangent direction θ of each point
_i is calculated as follows (S284a). 2 on the road
The points P _i−1 and P _i are converted into two points p _i−1 and p _i in the coordinate system (xy) of the host vehicle V, for example, as shown in FIG. In this coordinate system, the angle (rad) is for linear x-axis passing through the point _{p i-1, p i,} θ x = tan -1 ((x i -x i-1) / (y i -
y _i-1 )), and the angle (rad) of the straight line passing through the points p _i-1 and p _i with respect to the y-axis is θ _y = π / 2−θ _x . By the above, the angle (rad) with respect to the tangent of the y-axis at the midpoint p _m of each point p _i-1, p _{i is, θ i = π / 2-} tan -1 ((x i -x i-1) / (Y _i −
y _i-1 )). This angle θ _i is used for calculating the relaxation parameter A _i .

Based on the angle θ _i at each point P _i calculated as described above, the relaxation interval is determined as follows (S285a). Angle theta _i is a P _i that has changed to a finite value from zero (straight line) as a starting point P _o of the relaxation period. The point at which the relaxation parameter A _i calculated as follows using the angle θ _i changes from a constant value is defined as the end point P _{n of the} relaxation section.

When the relaxation section is determined as described above, the relaxation parameter _Ai is calculated as follows (S2).
86a). Distance from the origin P _o of the relaxation period to each point P _i L _i is L _i = is calculated according to _{(P o P 1 + P 1} P 2 + ... + P i-1 P i), the distance L _i and the point using tangential theta _i at P _i, relaxation parameters a _i is calculated according to ^{_{a i = (L i 2 /}} 2θ i) 1/2.

When the relaxation parameter A _i is calculated for each point P _i as described above, the average value is calculated in the same manner as above (the processing in FIG. 6). It is obtained as Ai or Ao (S287).
According to the above example, even before the vehicle V actually enters the curved road, the shape of the curved road ahead can be estimated.

In each of the above examples, step S shown in FIG.
1-S4, S11-17 and steps S21, S23,
The processing in S25 and the processing in step S28 shown in FIG. 5 correspond to the unique information detecting means, and the processing in step S2 shown in FIG.
2 and 23, step S29 shown in FIG. 5 and FIG.
Corresponds to the estimation calculating means.

[0054]

As described above, according to the present invention, the shape of the front running road is estimated based on the unique information determined from the design conditions of the running road ahead of the own vehicle. Therefore, even under bad conditions such as rain and fog,
In particular, it is possible to estimate a curved shape of a traveling path in a relatively wide range in front of the vehicle without photographing a distant place.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a hardware configuration of a traveling road shape estimation device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a curved road on which a vehicle travels.

FIG. 3 is a flowchart (part 1) illustrating a procedure of a process for estimating a shape of a curved road;

FIG. 4 is a flowchart (part 2) illustrating a procedure of a process for estimating a shape of a curved road;

FIG. 5 is a flowchart illustrating a procedure of a process for estimating a shape of a forward curved road in a straight traveling section.

6 is a flowchart showing a detailed procedure of a relaxation parameter estimation process in the procedure shown in FIG.

FIG. 7 is a diagram showing an example of the shape of a curved road.

FIG. 8 is a diagram showing coordinate conversion of forward road data.

FIG. 9 is a flowchart illustrating another detailed procedure of estimating a relaxation parameter in the procedure shown in FIG. 5;

FIG. 10 is a diagram illustrating an example of the shape of a curved road.

FIG. 11 is a diagram illustrating a relationship between points in a vehicle coordinate system.

[Explanation of symbols]

 Reference Signs List 10 control device 11 yaw rate sensor 12 wheel speed sensor 13 camera 14 register 20 navigation device 21 DGPS 22 map information reading unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G08G 1/16 G06F 15/62 380 // G05D 1/02 15/70 350M

Claims (4)

[Claims] 1. A position detecting means for detecting a traveling position of a host vehicle, a characteristic information detecting means for detecting characteristic information determined from a design condition of a traveling path ahead of a position detected by the position detecting means, and a characteristic information. A travel path shape estimating device comprising: an estimation operation means for calculating information representing a shape of a travel path ahead of a position detected by the position detection means based on the unique information detected by the detection means. 2. The travel path shape estimating device according to claim 1, wherein said unique information detection means detects a shape of the travel path at a travel position detected by the position detection means, and a position detection means. A travel path shape estimating device comprising: a unique information calculation means for calculating the unique information based on the travel position detected by the means and the shape of the travel path detected by the shape detection means. 3. The travel path shape estimating device according to claim 1, wherein said unique information detection means is configured to obtain a shape of the travel path obtained from map information including a travel path ahead of a position detected by the position detection means. A travel path shape estimating device comprising a unique information calculating means for calculating the unique information based on the information. 4. Position detecting means for detecting the running position of the vehicle, determining means for determining whether the running position detected by the position detecting means is a straight road portion or a curved road portion. When the means is determined to be a straight path portion, a unique characteristic determined from the design conditions of the travel path based on the shape of the travel path obtained from the map information including the travel path ahead of the position detected by the position detection means. First unique information calculating means for calculating information; and information representing a shape of a curved road portion ahead of the position detected by the position detecting means based on the unique information obtained by the first unique information calculating means. First shape calculation means for calculating the shape of the travel road at the travel position detected by the position detection means when the determination means determines that it is a curved road portion; Detected by the detection means A second unique information calculating means for calculating unique information determined from design conditions of the travel path based on the travel position and the shape of the travel path detected by the shape detection means; A traveling path shape estimating device comprising: a second estimating means for computing information representing the shape of the traveling path ahead of the position detected by the position detecting means based on the obtained unique information.