JP2000002535A - Method for detecting curvature of curve road and detector used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a curvature of a curve road frontward of an own vehicle simply and with excellent precision. SOLUTION: A speed vector of a frontward vehicle is introduced and an angle made by the speed vector and a traveling direction axis of an own vehicle is introduced (step S2), a lane displacement to a lane width direction of the frontward vehicle is calculated (step S3), by comparing this lane displacement with a specified value (corresponding to a lane width), it is decided whether or not the frontward vehicle is a preceding vehicle on the same lane as the own vehicle (step 4), and if decided to be the preceding vehicle (YES of step S4), by use of a distance between the preceding vehicle and the own vehicle and the angle made by the speed vector of the preceding vehicle and the traveling direction axis of the own vehicle, a curvature of a curve road is calculated (step S5). If decided that the frontward vehicle travels on a lane different from the own vehicle (NO of step S4), by use of a corrected inter-vehicle distance, the curvature of the curve road is calculated (step S6), and a standard value of the curvatures introduced based on the speed vector of the respective frontward vehicles is acquired (step S8).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a curvature of a curved road in front of a vehicle, and a detector for use in the method.

[0002]

2. Description of the Related Art Conventionally, as a method of detecting the curvature of a curved road ahead of a vehicle, the vehicle travels based on the yaw rate of the vehicle detected by a yaw rate sensor or the like or the steering angle detected by a steering angle sensor. Derivation of the curvature of the middle curved road has been performed.

On the other hand, in addition to the derivation of the curvature based on the yaw rate and the steering angle, the own vehicle is geometrically calculated from position information of a vehicle recognized as a preceding vehicle traveling in the same lane as the own vehicle. It has been proposed to detect the curvature of the curve in front of.

[0004] It has also been proposed to detect the curvature of a curve ahead of the host vehicle from a chronological change in the position of a vehicle recognized as a preceding vehicle traveling in the same lane as the host vehicle.

[0005]

However, in the case of the method of deriving the curvature based on the yaw rate and the steering angle of the own vehicle, the condition is that the own vehicle is already running on a curved road. However, there is a problem that the curvature cannot be detected for a curved road existing in the road.

Further, in the case of a method of deriving a curvature in consideration of the position of a vehicle recognized as a preceding vehicle, it is possible to detect the curvature of a curved road ahead of the own vehicle.
When the preceding vehicle changes lanes, the change in the position of the preceding vehicle is reflected as an error in the curvature, and there is a problem that the accuracy of detecting the position of the preceding vehicle greatly affects the detection of the curvature.

Further, when the curvature of a curved road ahead of the own vehicle is detected from the time-series change of the position of the preceding vehicle, there is a problem that the amount of calculation becomes extremely large.

An object of the present invention is to make it possible to easily and accurately detect the curvature of a curved road ahead of the vehicle.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for detecting a curvature of a curved road according to the present invention includes a position of a preceding vehicle traveling ahead of the own vehicle with respect to the own vehicle and a speed vector of the preceding vehicle. Based on the derived position and speed vector of the preceding vehicle, a lane displacement in the lane width direction of the preceding vehicle with respect to the traveling lane of the own vehicle is derived, and if the derived lane displacement is within a predetermined value, Judging that the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle, the angle between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and the distance between the own vehicle and the preceding vehicle From the distance, a curvature of a curved road ahead of the own vehicle in which the preceding vehicle is traveling is calculated, and if the lane displacement is not within the predetermined value, based on the lane displacement and the inter-vehicle distance to the preceding vehicle, Derived a corrected inter-vehicle distance when assuming the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle, the angle formed between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and the derived It is characterized in that the curvature of a curved road ahead of the own vehicle while the preceding vehicle is traveling is calculated from the corrected inter-vehicle distance.

According to such a configuration, it is determined whether or not the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle, based on whether or not the lane displacement derived based on the speed vector is within a predetermined value. . When it is determined that the vehicle is a preceding vehicle, the vehicle traveling in the traveling direction is determined based on the angle formed between the traveling direction of the vehicle and the direction axis of the velocity vector of the preceding vehicle, and the inter-vehicle distance between the vehicle and the preceding vehicle. The curvature of the curved road ahead of the own vehicle can be obtained by a simple calculation.

On the other hand, if it is determined that the preceding vehicle is not the preceding vehicle, the corrected headway based on the lane displacement and the inter-vehicle distance to the preceding vehicle is calculated based on the assumption that the preceding vehicle is the preceding vehicle traveling in the same lane as the own vehicle. The distance is derived, and from the angle formed between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and the derived corrected inter-vehicle distance, the curvature of the curved road ahead of the own vehicle while the preceding vehicle is traveling can be calculated by a simple calculation. can get.

Therefore, it is not necessary to perform a complicated operation as in the prior art, and the curvature of a curved road ahead of the vehicle can be accurately calculated by a simple operation.

In the method for detecting a curvature of a curved road according to the present invention, when there are a plurality of vehicles ahead, a curve road ahead of the own vehicle in which each of the preceding vehicles is traveling is based on a speed vector of each of the preceding vehicles. Are calculated respectively, and the average value of the calculated respective curvatures is obtained and used as the curvature of the curved road.

In this case, since the average value of each curvature calculated based on the velocity vectors of a plurality of vehicles ahead is obtained, the curvature of the curved road can be derived with higher accuracy.

Further, in the method for detecting a curvature of a curved road according to the present invention, an inter-vehicle distance sensor detects an inter-vehicle distance between the host vehicle and the preceding vehicle, and the detected inter-vehicle distance, the inter-vehicle distance sensor, and the front vehicle Is derived from the angle between the straight line connecting the vehicle and the traveling direction axis of the own vehicle in two-dimensional coordinates by the traveling direction axis and an axis orthogonal to the traveling direction axis. Based on the vehicle speed of the vehicle and the yaw rate of the vehicle, the speed vector of the preceding vehicle is derived, and the angle formed between the direction axis of the derived speed vector of the preceding vehicle and the traveling direction axis and the position of the preceding vehicle are derived from the angle. It is characterized by deriving lane displacement.

This makes it possible to derive the speed vector of the preceding vehicle and to derive the lane displacement based on this.

In the method for detecting a curvature of a curved road according to the present invention, the predetermined value is substantially equal to a lane width.

In this case, it is determined whether or not the lane displacement is within a predetermined lane width, and it is easy to determine whether the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle.

The curvature detecting device used in the method for detecting the curvature of a curved road according to the present invention includes an inter-vehicle distance sensor for detecting an inter-vehicle distance between the own vehicle and a preceding vehicle traveling ahead of the own vehicle, and a vehicle speed of the own vehicle. A wheel speed sensor for detecting, a yaw rate sensor for detecting a yaw rate of the own vehicle, and a calculating means for calculating a curvature of a curve in front of the own vehicle based on an output signal of each of the sensors, wherein the calculating means comprises: The forward distance in two-dimensional coordinates based on the traveling direction axis and an axis perpendicular to the traveling direction axis, based on the inter-vehicle distance by a sensor, and the angle between a straight line connecting the inter-vehicle distance sensor and the forward vehicle and the traveling direction axis of the own vehicle. A position deriving unit for deriving a position of the vehicle, a position of the preceding vehicle by the position deriving unit, a vehicle speed of the own vehicle by the wheel speed sensor, and the yaw rate sensor of the own vehicle Based on the yaw rate by a velocity vector derivation unit that derives the velocity vector of the preceding vehicle,
A lane displacement deriving unit that derives the lane displacement from an angle between the direction axis of the speed vector of the preceding vehicle and the traveling direction axis and the position of the preceding vehicle, and the lane displacement deriving unit, A determining unit that determines whether the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle based on whether the lane displacement is within a predetermined value, and determining that the preceding vehicle is a preceding vehicle by the determining unit When the vehicle travels on a curved road ahead of the host vehicle based on the angle formed by the traveling direction axis and the direction axis of the speed vector of the preceding vehicle and the inter-vehicle distance between the host vehicle and the preceding vehicle. When the curvature is calculated and the determination unit determines that the preceding vehicle is not the preceding vehicle,
Based on the lane displacement and the inter-vehicle distance with the preceding vehicle,
Derived a corrected inter-vehicle distance when assuming that the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle, an angle between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and derived. A calculating unit that calculates a curvature of a curved road ahead of the own vehicle while the preceding vehicle is traveling from the corrected inter-vehicle distance.

According to such a configuration, the speed vector of the preceding vehicle is derived by the speed vector deriving unit constituting the calculating means, the lane displacement is derived by the lane displacement deriving unit, and the derived lane displacement is determined by the determining unit. Is within a predetermined value, it is determined whether or not the preceding vehicle is the preceding vehicle.

When it is determined that the vehicle is the preceding vehicle,
The calculating unit that constitutes the calculating means determines, based on the angle formed between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and the inter-vehicle distance between the own vehicle and the preceding vehicle, the preceding vehicle in which the preceding vehicle is traveling. Can be obtained by a simple calculation. On the other hand, if it is determined that the preceding vehicle is not the preceding vehicle, the arithmetic unit calculates a correction based on the lane displacement and the inter-vehicle distance to the preceding vehicle, assuming that the preceding vehicle is the preceding vehicle traveling in the same lane as the own vehicle. The inter-vehicle distance is derived, and from the angle formed between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and the derived corrected inter-vehicle distance, the curvature of a curved road ahead of the own vehicle while the preceding vehicle is traveling is easily calculated. Is obtained by Therefore, it is not necessary to perform complicated calculations as in the related art, and it is possible to accurately calculate the curvature of a curved road ahead of the vehicle by simple calculations.

Further, in the curvature detecting device for a curved road according to the present invention, the calculating means calculates a curvature of the curved road ahead of the own vehicle while each of the preceding vehicles is traveling, based on the velocity vectors of the plurality of preceding vehicles. Each of the calculations is performed, an average value of the calculated curvatures is obtained, and the calculated average value is used as the curvature of the curved road.

In this way, the curvature of the curved road can be derived with higher accuracy by taking the average of the curvatures calculated based on the velocity vectors of a plurality of vehicles ahead.

Further, in the curvature detecting device for a curved road according to the present invention, the inter-vehicle distance sensor scans a laser beam at a predetermined angle in a direction perpendicular to a traveling direction axis of the own vehicle and irradiates the vehicle with the laser beam at a predetermined angle. It consists of a scan laser radar that receives the reflected light from the vehicle and calculates the inter-vehicle distance from the own vehicle to the preceding vehicle based on the time and light speed from irradiating the laser light at each irradiation point to receiving the reflected light. It is characterized by:

In this case, the inter-vehicle distance sensor can be accurately detected by forming the inter-vehicle distance sensor by a scanning laser radar.

Further, the curvature detecting device for a curved road according to the present invention is characterized in that the predetermined value is substantially equal to the lane width.

In this manner, it is determined whether or not the lane displacement is within the predetermined lane width, and it is easy to determine whether the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. 1 is a block diagram, FIGS. 2 to 4 are operation explanatory diagrams, and FIG. 5 is a flowchart for operation explanation.

First, the configuration of the system will be described.
In FIG. 1, reference numeral 1 denotes an inter-vehicle distance sensor, which is constituted by, for example, a scan laser radar made of a semiconductor laser or the like, and its reflection angle is adjusted by a mirror which is rotated by a predetermined angle such as 1 ° by a stepping motor or the like. The laser beam thus scanned is scanned in the direction orthogonal to the traveling direction axis of the own vehicle, and the laser beam scanned at a predetermined angle in this manner is irradiated on the preceding vehicle, and a light receiving element such as a phototransistor built in the following distance sensor 1 (see FIG. (Not shown), the reflected light from the vehicle in front is received, and the received light signal
U, and the ECU calculates the inter-vehicle distance from the own vehicle to the preceding vehicle based on the time from the irradiation of the laser beam at each irradiation point to the reception of the reflected light and the speed of light. At this time, since the irradiation angle of the laser beam to each irradiation point is known, the angle formed by the straight line connecting the inter-vehicle distance sensor 1 and each irradiation point with the traveling direction axis of the own vehicle is also derived.

In FIG. 1, reference numeral 2 denotes a wheel speed sensor for detecting the vehicle speed of the own vehicle, 3 denotes a yaw rate sensor for detecting the yaw rate of the own vehicle, and 4 denotes an ECU. In addition to functioning as a calculation means for performing the calculation of the above, the display unit 5 for displaying the calculation result and the like, and a traveling control device 6 for performing automatic braking under predetermined conditions in order to avoid a collision are also controlled.

The function of the ECU 4 as the calculation means will be described in detail. The following describes the distance between the own vehicle detected by the following distance sensor 1 and the preceding vehicle running ahead of the own vehicle, and the distance between the own vehicle and the preceding vehicle. Are the two-dimensional coordinates of the X-axis and an axis orthogonal thereto (hereinafter, referred to as the Y-axis) from the angle formed by the straight line connecting the axis and the traveling direction axis (hereinafter, referred to as the X-axis) of the vehicle. The position of the preceding vehicle in the XY coordinate system is derived. Such a position deriving process corresponds to a position deriving unit.

Then, a speed vector of the preceding vehicle is derived based on the derived position of the preceding vehicle, the vehicle speed of the own vehicle by the wheel speed sensor 2 and the yaw rate of the own vehicle by the yaw rate sensor 3. This processing corresponds to a speed vector deriving unit. Further, a lane displacement in the lane width direction of the front vehicle with respect to the traveling lane of the own vehicle is derived from the angle formed between the direction axis of the derived front vehicle speed vector and the X axis and the position of the front vehicle. This processing corresponds to a lane displacement deriving unit.

It is determined whether or not the preceding vehicle is the preceding vehicle traveling in the same lane as the own vehicle, based on whether or not the derived lane displacement is within a value equal to the predetermined lane width (for example, 2 m). Such a determination process corresponds to a determination unit.

When it is determined that the preceding vehicle is the preceding vehicle, the preceding vehicle is determined based on the angle between the traveling direction axis of the own vehicle and the direction axis of the speed vector of the preceding vehicle and the inter-vehicle distance between the own vehicle and the preceding vehicle. The curvature of a curved road ahead of the vehicle while the vehicle is running is calculated. On the other hand, when it is determined that the preceding vehicle is not the preceding vehicle, the corrected inter-vehicle distance when the preceding vehicle is assumed to be the preceding vehicle traveling in the same lane as the own vehicle is determined based on the lane displacement and the inter-vehicle distance with the preceding vehicle. Then, a curvature of a curved road ahead of the own vehicle while the preceding vehicle is running is calculated from the angle formed between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle and the derived corrected inter-vehicle distance. Such a curvature calculation process corresponds to a calculation unit. Note that, when there are a plurality of vehicles in front, the arithmetic unit performs a process of taking the average of the curvatures of the curved roads derived based on the speed vectors of the respective forward vehicles to obtain the curvature of the curved road. .

Now, the principle of deriving the lane displacement at this time will be described. In the case where the own vehicle and the preceding vehicle traveling in front of it are in the state shown in FIG. The position is represented by the center point P of the rear end, the angle and the intersection between the speed vector V of the preceding vehicle and the X axis are respectively θ and the point Q, and the center point of the front end and the center point of the rear end of the own vehicle are O and
N, and the length of the own vehicle is L, assuming that the own vehicle and the preceding vehicle are running on the same lane on a curved road having the same curvature with the point M as the center of curvature, the right triangle MPQ and the right triangle Since the MNQs are congruent, the relationship PQ = QO + L holds.

Then, the X coordinate Px and the Y coordinate Py of the point P
Is the inter-vehicle distance by the inter-vehicle distance sensor 1 as described above,
And the X coordinate P of the point P calculated and derived from the angle between the X axis and the straight line connecting the inter-vehicle distance sensor 1 and the vehicle in front.
The velocity vector V of the preceding vehicle is derived based on the x, Y coordinate Py, the vehicle speed of the own vehicle, and the yaw rate of the own vehicle. The above-described angle θ is obtained from the X-axis component Vx and the Y-axis component Vy of the speed vector V according to Equation 1. Is calculated.

[0037]

(Equation 1)

Therefore, based on the above condition (PQ = QO + L), the lane displacement d in the lane width direction of the preceding vehicle with respect to the traveling lane of the own vehicle can be expressed as in equation (2). , Py, and the X-axis and Y-axis components Vx, Vy of the calculated velocity vector V are substituted for the angle θ to obtain the lane displacement d. By determining whether the magnitude of d is greater than a predetermined value w (for example, 2 m) substantially equal to the lane width, it is possible to determine whether the preceding vehicle is traveling in the same lane as the own vehicle.

[0039]

(Equation 2)

In equation (2), L0 represents the amount of deviation (see FIG. 2) from the center axis of the own vehicle to the installation position of the inter-vehicle distance sensor 1.

The speed vector of the preceding vehicle is usually obtained from the inter-vehicle distance at a certain processing time and the inter-vehicle distance at the next processing time. In the case of the speed vector thus obtained, the influence of noise increases. Therefore, in the present embodiment, a speed vector is derived by performing a calculation using a Kalman filter in order to improve the accuracy.

That is, when the own vehicle and the preceding vehicle at a certain time k and a next time k + 1 are in a positional relationship as shown in FIG. 3A (the broken line in FIG. Indicates the time k + 1), first, the position, speed, and acceleration of the preceding vehicle at the time k in the coordinate system of the own vehicle at the time k are used to determine the state of the preceding vehicle at that time, and then as shown in FIG. Then, the state of the preceding vehicle at time k + 1 in the coordinate system at time k of the vehicle when it is assumed that the vehicle is stopped is calculated.

Further, as shown in FIG. 3 (c), the amount of movement of the own vehicle is subtracted from the position of the preceding vehicle to reversely rotate by the turning component α of the own vehicle. Replacement with the state of the preceding vehicle at time k + 1 is performed. At this time, using the Kalman gain of the Kalman filter, the state of the preceding vehicle at time k + 1 in the coordinate system at time k + 1 of the own vehicle can be derived with high accuracy from the output value of each sensor.
The velocity vector can be derived with high accuracy from the state of the preceding vehicle at +1 and the state of the preceding vehicle at time k in the coordinate system of the vehicle at time k.

Here, Px and Py in FIG. 3 represent the X and Y coordinates of the preceding vehicle, and the suffixes k and k + 1 of X and Y represent the XY coordinate system at time k and time k + 1 of the own vehicle, respectively. , P
The subscripts k and k + 1 of y are time k and time k +
1 represents the X and Y coordinates of the preceding vehicle in each of the XY coordinate systems.

The speed vector of the preceding vehicle is derived by the ECU 4 as described above, and the lane displacement d of the preceding vehicle is derived based on the speed vector.
Based on a comparison between the lane displacement d and a predetermined value corresponding to the lane width, the CU 4 determines that the preceding vehicle is the preceding vehicle traveling in the same lane as the own vehicle as shown in FIG. The curvature R of the curved road is calculated by the calculation of Expression 3 from the inter-vehicle distance D to the preceding vehicle and the angle θ between the speed vector of the preceding vehicle and the traveling direction axis of the own vehicle.

[0046]

(Equation 3)

On the other hand, from the comparison between the lane displacement d and the predetermined value corresponding to the lane width by the ECU 4, the preceding vehicle is a vehicle traveling on a lane different from the own vehicle, as shown by the one-dot chain line in FIG. Is determined, using the actual inter-vehicle distance D between the own vehicle and the preceding vehicle and the lane displacement d, the corrected inter-vehicle distance when traveling on the same lane as the own vehicle is calculated by the equation (4). The distance D 'is calculated, and the curvature R of the curved road is calculated by calculation using the corrected inter-vehicle distance D' instead of D in Expression 3.

[0048]

(Equation 4)

When there are a plurality of vehicles ahead, regardless of whether or not the vehicle is traveling in the same lane as the own vehicle, the average of the curvature of the curved road derived based on the speed vector of each vehicle ahead is calculated, and the calculated value is calculated. Is the curvature of the curved road.

Next, a series of operations will be described with reference to the flowchart of FIG.

As shown in FIG. 5, based on the output signal of the inter-vehicle distance sensor 1, a vehicle in front of the own vehicle is recognized (step S1), and a speed vector of the preceding vehicle is derived, and the speed is calculated. The angle θ formed between the vector and the traveling direction axis of the own vehicle is derived by the above-described calculation of Expression 1 (Step S2).

Subsequently, the lane displacement d of the preceding vehicle is calculated by the calculation of the above formula 2 (step S3), and the calculated lane displacement d is compared with a predetermined value corresponding to the lane width.
It is determined whether or not the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle (step S4).
In the case of ES, the curvature of the curved road is calculated by the above equation 3 using the inter-vehicle distance D between the own vehicle and the preceding vehicle and the angle θ between the speed vector of the preceding vehicle and the traveling direction axis of the own vehicle. R is calculated (step S5).

On the other hand, if the decision result in the step S4 is NO, it is determined that the preceding vehicle is traveling on a lane different from the own vehicle, and the preceding vehicle of the formula 3 using the corrected inter-vehicle distance D 'by the above formula 4 is determined. The calculation is performed to calculate the curvature R of the curved road (step S6), and then the process goes to step S7 after passing through the processing of step S5 described above.

Then, it is determined whether or not the above-described calculation of the curvature based on the velocity vectors of all the preceding vehicles has been completed (step S7). If the determination result is NO, the process returns to step S2 and returns to step S2. The subsequent processing is repeated, and if the determination result is YES, an average value of the curvature R derived based on the velocity vector of each preceding vehicle is obtained (step S8), and the obtained average value of the curvature R is calculated based on the curve. The curvature of the road is set, and then the operation ends. still,
The speed vector is derived again for the preceding vehicle whose lane change has been performed on the way, the curvature is calculated, and used for calculating the average value.

Therefore, according to the above-described embodiment, if the preceding vehicle is determined to be the preceding vehicle, the angle θ between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, From the inter-vehicle distance D between the vehicle and the preceding vehicle, the curvature R of the curved road ahead of the own vehicle while the preceding vehicle is traveling is obtained by a simple calculation, and if it is determined that the preceding vehicle is not the preceding vehicle, the lane displacement d and Based on the inter-vehicle distance D to the preceding vehicle, the curvature R of the curved road ahead of the own vehicle while the preceding vehicle is traveling is calculated from the corrected inter-vehicle distance D 'when the preceding vehicle is assumed to be the preceding vehicle traveling in the same lane as the own vehicle. Since it can be obtained by a simple calculation, there is no need to perform a complicated calculation as in the related art.
Can be accurately calculated.

Further, since the average value of each curvature R calculated based on the velocity vectors of a plurality of vehicles ahead is obtained, the curvature of the curved road can be derived with higher accuracy.

Further, by judging whether or not the lane displacement d is within a predetermined lane width (for example, 2 m), it is easy to judge whether or not the preceding vehicle is the preceding vehicle traveling in the same lane as the own vehicle. It becomes possible to do.

Further, by forming the inter-vehicle distance sensor 1 by a scanning laser radar, the inter-vehicle distance can be detected with high accuracy.

In the above-described embodiment, the case has been described in which the inter-vehicle distance sensor 1 is constituted by a scan laser radar, but it goes without saying that the inter-vehicle distance sensor 1 is not limited to a scan laser radar.

Further, in the above-described embodiment, the case where the travel control device 6 for preventing a rear-end collision is provided has been described. However, the present invention can be similarly implemented even without this travel control device. It is possible to do.

Further, the present invention is not limited to the above-described embodiment, and various changes other than those described above can be made without departing from the gist of the present invention.

[0062]

As described above, according to the first and fifth aspects of the present invention, it is not necessary to perform a complicated operation unlike the prior art, so that the curvature of a curved road ahead of the own vehicle can be accurately calculated by a simple operation. Can be calculated well.

Further, regardless of whether or not the preceding vehicle is traveling in the same lane as the own vehicle, the curvature of the curved road can be easily and accurately detected based on the speed vector of the preceding vehicle.

According to the second and sixth aspects of the present invention, the curvature of the curved road is derived with higher accuracy by taking the average value of each curvature calculated based on the velocity vectors of a plurality of vehicles ahead. can do.

Further, according to the third aspect of the present invention, it is possible to derive the speed vector of the preceding vehicle and to easily derive the lane displacement based on this.

According to the fourth and eighth aspects of the present invention, whether or not the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle depends on whether or not the lane displacement is within a predetermined lane width. It is possible to easily determine.

According to the seventh aspect of the present invention, since the inter-vehicle distance sensor is constituted by a scanning laser radar, the inter-vehicle distance can be detected with high accuracy, and the detection accuracy of the curvature of a curved road can be improved. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is an operation explanatory diagram of one embodiment.

FIG. 3 is an operation explanatory diagram of one embodiment.

FIG. 4 is a diagram illustrating an operation of the embodiment.

FIG. 5 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

 1 inter-vehicle distance sensor 2 wheel speed sensor 3 yaw rate sensor 4 ECU (calculation means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // G01S 13/93 G01S 13/93 Z F term (reference) 2F112 AD01 BA06 BA09 BA18 CA05 CA20 DA15 DA25 DA28 FA45 FA50 5H180 AA01 BB15 CC03 CC14 LL04 5J070 AA01 AC01 AC03 AC06 AC13 AC20 AE01 AF03 AG09 AK22 BF19 BF20 5J084 AA02 AA04 AA05 AA07 AA10 AB01 AB20 AD01 AD06 AD07 BA04 BA11 BA36 BA49 CA12 CA19 CA31 DA09 EA

Claims (8)

[Claims] 1. Deriving a position of a preceding vehicle traveling ahead of the own vehicle with respect to the own vehicle and a speed vector of the preceding vehicle,
Based on the derived position and speed vector of the preceding vehicle, derive a lane displacement in the lane width direction of the preceding vehicle with respect to the traveling lane of the own vehicle. If the derived lane displacement is within a predetermined value, the preceding vehicle is determined. It is determined that the vehicle is a preceding vehicle traveling in the same lane as the own vehicle, and from the angle between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle and the inter-vehicle distance between the own vehicle and the preceding vehicle, Calculates the curvature of a curved road ahead of the own vehicle while the preceding vehicle is traveling, and if the lane displacement is not within the predetermined value, the preceding vehicle is controlled based on the lane displacement and the inter-vehicle distance to the preceding vehicle. And the corrected inter-vehicle distance when assuming the preceding vehicle traveling in the same lane is calculated from the angle between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and the derived inter-vehicle distance. Curvature detecting method of the curved road, characterized in that the front vehicle is computed curvature of the curved road in front of the vehicle traveling. 2. When there are a plurality of the preceding vehicles, the curvature of a curved road in front of the own vehicle while each of the preceding vehicles is traveling is calculated based on the velocity vector of each of the preceding vehicles. 2. The method for detecting a curvature of a curved road according to claim 1, wherein an average value of the calculated curvatures is obtained and used as the curvature of the curved road. 3. An inter-vehicle distance sensor detects an inter-vehicle distance between the own vehicle and the preceding vehicle, and the detected inter-vehicle distance, a straight line connecting the inter-vehicle distance sensor and the preceding vehicle, and a traveling direction axis of the own vehicle. From the angle formed, the position of the preceding vehicle in two-dimensional coordinates by the traveling direction axis and the axis orthogonal thereto is derived, based on the derived position of the preceding vehicle, the vehicle speed of the own vehicle, and the yaw rate of the own vehicle, And deriving a speed vector of the preceding vehicle, and deriving the lane displacement from an angle between a direction axis of the derived speed vector of the preceding vehicle and the traveling direction axis and a position of the preceding vehicle. Item 3. The method for detecting a curvature of a curved road according to item 1 or 2. 4. The method according to claim 1, wherein the predetermined value is substantially equal to a lane width. 5. An inter-vehicle distance sensor for detecting an inter-vehicle distance between the own vehicle and a preceding vehicle traveling in front of the own vehicle, a wheel speed sensor for detecting a speed of the own vehicle, and a yaw rate sensor for detecting a yaw rate of the own vehicle. And calculating means for calculating a curvature of a curve in front of the own vehicle based on output signals of the sensors, wherein the calculating means includes: the inter-vehicle distance by the inter-vehicle distance sensor, and the inter-vehicle distance sensor and the front vehicle. A position deriving unit that derives the position of the preceding vehicle in two-dimensional coordinates by the traveling direction axis and an axis orthogonal to the traveling direction axis from an angle formed by a straight line connecting the vehicle and the traveling direction axis of the own vehicle; A speed vector for deriving a speed vector of the preceding vehicle based on the position of the preceding vehicle, the vehicle speed of the own vehicle by the wheel speed sensor, and the yaw rate of the own vehicle by the yaw rate sensor. A vector deriving unit, a lane displacement deriving unit that derives the lane displacement from an angle formed between a direction axis of the speed vector of the preceding vehicle and the traveling direction axis by the speed vector deriving unit and the position of the preceding vehicle, A determining unit that determines whether the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle based on whether or not the lane displacement by the displacement deriving unit is within a predetermined value; and When it is determined that the vehicle is a vehicle, the vehicle traveling by the preceding vehicle is based on the angle formed between the traveling direction axis and the direction axis of the speed vector of the preceding vehicle and the inter-vehicle distance between the vehicle and the preceding vehicle. Calculates the curvature of a curved road ahead, and based on the lane displacement and the inter-vehicle distance to the preceding vehicle when the determining unit determines that the preceding vehicle is not the preceding vehicle. Derived a corrected inter-vehicle distance when assuming that the preceding vehicle is a preceding vehicle traveling in the same lane as the own vehicle, an angle between the traveling direction of the own vehicle and the direction axis of the speed vector of the preceding vehicle, and derived. A calculating section for calculating a curvature of a curved road ahead of the own vehicle while the preceding vehicle is traveling, from the corrected inter-vehicle distance. 6. The calculation means calculates a curvature of a curved road in front of the own vehicle while each of the preceding vehicles is traveling, based on speed vectors of the plurality of preceding vehicles, respectively, and calculates the calculated respective ones. The curvature detecting device for a curved road according to claim 5, wherein an average value of the curvatures is obtained and used as the curvature of the curved road. 7. The inter-vehicle distance sensor scans a laser beam at a predetermined angle in a direction orthogonal to a traveling direction axis of the own vehicle to irradiate the preceding vehicle, and receives reflected light from the preceding vehicle,
6. A scanning laser radar for calculating an inter-vehicle distance from a host vehicle to a preceding vehicle based on a time and a light speed from irradiation of laser light to reception of reflected light at each irradiation point. 7. The curvature detecting device for a curved road according to 6. 8. The curvature detecting device for a curved road according to claim 5, wherein the predetermined value is substantially equal to a lane width.