JP5516043B2 - Travel control device - Google Patents

Description

  The present invention relates to a travel control device.

  Conventionally, by irradiating a laser beam forward in the vehicle direction and scanning in the vehicle width direction (forward scan), a white line (running road) attached to the preceding vehicle, an obstacle in front of the vehicle direction, or a road surface An in-vehicle radar device that detects a categorization line or the like is known (for example, see Patent Document 1).

JP 2000-147124 A

  However, since the above-described on-vehicle radar device scans the laser in an arc shape, a white line crossing the road such as a stop line cannot be detected unless the sampling cycle is shortened. However, if the sampling period is shortened, it takes time to process the data, which may cause a delay in vehicle control.

  The present invention has been made in view of such a conventional problem. The object of the present invention is to detect a white line that crosses a road such as a stop line without shortening the sampling period, and is appropriate. It is to provide a travel control device that enables travel control at timing.

  A feature of the present invention is that a light beam is generated from a first beam generating means mounted on a vehicle, and the light beam is tilted vertically downward by a first angle with respect to the front of the vehicle, and with respect to the front of the vehicle. The vehicle is tilted and fixed in the vehicle width direction by the second angle, scanned across the center of the lane width, and the reflected light of the light beam reflected on the road ahead of the vehicle is received to detect the vehicle speed. The position of the reflected light is calculated based on the speed of the vehicle, the white line extending in the vehicle width direction on the road is detected based on the position of the reflected light, and the vehicle travels based on the white line and the speed of the vehicle. In the travel control device that performs control, the second angle is determined by the travel speed and the scanning period of the light beam.

  According to the travel control device of the present invention, it is possible to detect a white line crossing a road such as a stop line without shortening the sampling cycle, and travel control can be performed at an appropriate timing.

It is a block diagram which shows the structure of the traveling control apparatus concerning the 1st Embodiment of this invention. FIG. 2A is a schematic diagram showing a light beam LB emitted toward the front of the vehicle from the vehicle SC on which the traveling control device of FIG. 1 is mounted, and FIG. It is a schematic diagram which shows the scanning area | region of the irradiated light beam LB. It is a flowchart which shows an example of the control procedure performed by the traveling control apparatus of FIG. It is a flowchart of an example of the detailed process sequence of stop line detection shown to step S130 of FIG. FIG. 5 is a schematic diagram illustrating an instruction display, a restriction display, and a lane marking image indicating that there is a pedestrian crossing, a stop line, a pedestrian crossing, or a bicycle crossing band as an example of an image extracted in step S210 of FIG. It is a schematic diagram which shows an example of the group results G1-G8 extracted in step S230 of FIG. FIG. 7A is a schematic diagram showing a direction in which the light beam is tilted in the vehicle width direction when traveling on the right curve when the traffic segment is on the left side, and FIG. 7B is a diagram showing the traffic segment on the left side. It is a schematic diagram showing a direction in which a light beam is tilted in the vehicle width direction when traveling on the left curve. It is a block diagram which shows the structure of the traveling control apparatus concerning the 4th Embodiment of this invention. FIG. 9A and FIG. 9B are top views showing the irradiation position trajectories RP1 and RP2 in the fourth embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In the description of the drawings, the same parts are denoted by the same reference numerals.

(First embodiment)
With reference to FIG. 1, the structure of the traveling control apparatus concerning the 1st Embodiment of this invention is demonstrated. The travel control apparatus according to the first embodiment includes a first light beam generation unit (first light beam generation unit) 10 that generates a light beam, and a light beam generated by the first light beam generation unit 10. A first light beam scanning unit (first light beam scanning means) 15 for scanning the vehicle on the road ahead of the vehicle, and a first light receiving unit for receiving the reflected light of the light beam reflected on the road ahead of the vehicle (First light receiving means) 20, a vehicle speed detecting section (vehicle speed detecting means) 40 for detecting the speed of the vehicle, and the first light receiving section 20 receives light based on the vehicle speed detected by the vehicle speed detecting section 40. A reflection position calculation unit (reflection position calculation unit) 25 that calculates the position of the reflected light; a reflection position storage unit (reflection position storage unit) 30 that stores the position of the reflection light calculated by the reflection light position calculation unit 25; The reflection stored in the reflected light position storage unit 30 Based on the position of the light, the white line detecting unit (white line detecting means) 50 for detecting a white line extending in the vehicle width direction on the road, the white line detected by the white line detecting unit 50, and the vehicle speed detected by the vehicle speed detecting unit 40 And a travel control unit (running control means) 60 for controlling the travel of the vehicle.

  FIG. 2A is a schematic diagram showing a light beam LB emitted toward the front of the vehicle from the vehicle SC on which the traveling control device of FIG. 1 is mounted, and FIG. It is a schematic diagram which shows the scanning area | region of the irradiated light beam LB.

  The light beam LB generated by the first light beam generator 10 mounted on the front surface of the vehicle SC is emitted downward by a first angle α in the vertical direction as shown in FIG. .

  As shown in FIG. 2B, the first light beam scanning unit 15 scans the light beam LB in the horizontal scanning angle range γ. At this time, the scanning angle range γ is desirably an angle range in which white lines at both ends of the traveling lane can be detected.

The irradiation position of the light beam LB irradiated on the road moves by scanning the light beam LB. As shown in FIG. 2B, the locus RP of the irradiation position of the light beam LB crosses the center portion in the vehicle width direction and forms a second angle θ in the vehicle longitudinal direction with respect to the vehicle width direction. . The second angle θ is determined by the traveling speed and the scanning period f of the light beam LB. In the embodiment of the present invention, the locus RP forms a line segment, but the entire locus RP may be a curved line or a part of the locus RP may be a curved line.

  In this way, the first light beam scanning unit 15 first tilts the light beam LB generated by the first light beam generation unit 10 vertically downward by the first angle α with respect to the front of the vehicle, and The vehicle is tilted and fixed in the vehicle width direction by a second angle θ with respect to the front of the vehicle. Then, the light beam LB is scanned in the scanning angle range γ so as to cross the center of the lane width, with the direction tilted in the vehicle width direction by the second angle θ with respect to the front of the vehicle. The second angle θ is determined by the vehicle traveling speed V and the light beam scanning period f.

  Specifically, when the vehicle-mounted height of the first light beam generator 10 is H and the travel lane width is W, the scanning angle range γ may be set according to the equation (1). Accordingly, it is possible to set a scanning angle range γ in which white lines at both ends of the traveling lane can be detected.

      γ> arctan (Wtan α / 2H cos θ) (1)

For example, the first angle α is 0.08 [rad] (about 4.6 °), the second angle θ is 0.35 [rad] (about 20 °), and the in-vehicle height H of the light beam generator 10 is set. Is 0.5 [m] and the traveling lane width W is 3 [m], γ can be set to 0.25 [rad] (about 14 °) or more from the equation (1).

  The first light receiving unit 20 receives the reflected light of the light beam LB, and detects at least the relative position of the reflected light with respect to the vehicle SC and the intensity of the reflected light.

  Based on the relative position of the reflected light with respect to the vehicle SC, the position of the vehicle SC, and the speed V of the vehicle SC detected by the vehicle speed detection unit 40, the reflection position calculation unit 25 receives light from the first light receiving unit 20. The position of the reflected light is calculated. The reflection position storage unit 30 stores the position of the reflected light calculated by the reflected light position calculation unit 25 and the intensity of the reflected light in association with each other.

  First, the white line detection unit 50 detects a white line based on the position of the reflected light and the intensity of the reflected light stored in the light emission position storage unit 30. Thereafter, of the detected white lines, a white line extending in the vehicle width direction on the road is detected as a stop line.

  With reference to FIG. 3, an example of a control procedure performed by the travel control device of FIG. 1 will be described.

  First, in step S110 in FIG. 3, the light beam LB is generated by the first light beam generator 10, and the light beam LB is scanned by the first light beam scanner 15 as shown in FIG. At the same time, the first light receiving unit 20 receives the reflected light of the light beam LB, and detects the relative position of the reflected light with respect to the vehicle and the intensity of the reflected light.

  Next, in step S120, the position of the reflected light is calculated from the position of the vehicle SC, the relative position of the reflected light with respect to the vehicle SC detected in step S110, and the speed V of the vehicle SC detected by the vehicle speed detection unit 40. . Then, the calculated position of the reflected light is stored in the reflection position storage unit 30 in association with the intensity of the reflected light detected in step S110. The position p of the vehicle SC may be p = 0 in the initial state.

  Next, in step S130, a white line (stop line) extending in the vehicle width direction on the road is detected from the position of the reflected light stored in the reflection position storage unit 30 and the intensity of the reflected light. When the stop line is detected, the distance L to the stop line is acquired. An example of a detailed processing procedure of stop line detection in step S130 is shown in the flowchart of FIG.

  First, in step S210 of FIG. 4, a road marking image is extracted from the position of the reflected light and the intensity of the reflected light stored in the reflection position storage unit 30. Using the fact that the road marking has a higher reflectance than that of asphalt, a portion where the reflected light is strong is extracted as an image of the road marking. Thereby, for example, as shown in FIG. 5, an instruction display such as a pedestrian crossing, a stop line, a pedestrian crossing or a bicycle crossing zone, a regulation display, and an image of a division line can be obtained. A plurality of parallel oblique lines shown in FIG. 5 correspond to the locus RP of the irradiation position of the light beam LB in FIG.

  In step S220, a white line is detected from the result extracted in step S210. Various methods are known for detecting a white line. Here, a straight line (or a curved line) is detected by Hough transform, and a detected line having a length of a predetermined value (for example, 10 m) or more is defined as a white line. To detect.

  In step S230, a stop line is detected based on the image extracted in step S210 and the white line detected in step S220. First, clustering is performed between scan points that are close to each other in the image extracted in step S210. Next, the clustering results are grouped in a direction perpendicular to the white line (tangent in the case of a curve) detected in step S220. Further, it is determined whether or not there are other grouping results within a predetermined distance (for example, 0.5 m) in a direction parallel to the white line of each grouping result. As a result, for example, several group results G1 to G8 as shown in FIG. 6 are extracted. Among the grouping results G1 to G8, the grouping result G2 whose magnitude in the direction parallel to the white line detected in step S220 is within a predetermined range (for example, 0.3 m or more and 0.5 m or less) is detected as a stop line. .

  Proceeding to step 140 in FIG. 3, the vehicle speed detection unit 40 detects the speed V of the host vehicle.

  In step 150, the necessity of travel control is determined based on the distance L to the stop line acquired in step S130 and the speed V of the host vehicle detected in step S140. When the distance L to the stop line and the speed V of the host vehicle satisfy the equation (2) (YES in S150), it is determined that traveling control is necessary, and the process proceeds to step 160, and the equation (2) is not satisfied ( If NO in S150, it is determined that traveling control is not necessary, and the routine proceeds to step 170. Here, β is a coefficient related to the deceleration required for stopping, for example, β = 8.

L <V ² / 2β (2)

  In step S160, the brake of the own vehicle is controlled so that it can stop at a stop line.

  In step S170, it is determined whether or not the ignition switch (IGN) is turned off. If it is turned off (YES in S170), the process flow of FIG. 3 is terminated. If it is not turned off (NO in S170), the process returns to step S110.

  According to the first embodiment of the present invention, the following operational effects can be obtained.

  The light beam generated by the first light beam generator 10 is tilted vertically downward by a first angle α with respect to the front of the vehicle, and tilted in the vehicle front-rear direction by a second angle θ with respect to the vehicle width direction. Scan it across the center of the lane width. As a result, as shown in FIG. 2B, the locus RP (scanning line) of the irradiation position crosses the center of the lane width, so the sampling cycle is shortened even for the white line crossing the road such as the stop line. Therefore, it is possible to detect the vehicle and control the traveling at an appropriate timing.

(Second Embodiment)
In the second embodiment, a case will be described in which the second angle θ to be tilted in the vehicle width direction is determined according to the maximum speed at which traveling control is performed or the scanning cycle. Note that the configuration and processing contents of the travel control apparatus according to the second embodiment are the same as those in the first embodiment, and illustration and description thereof are omitted.

  The second angle θ is set so as to satisfy Equation (3), where f is the period (scanning period) at which the first light beam scanning unit 15 scans the light beam and Vmax is the maximum speed at which traveling control is performed. To do.

Here, L is a half value of the length of the object to be detected in the vehicle width direction. For example, when the object to be detected is the same stop line as that of the first embodiment, L = 2. [m] / 2 = 1. δ is an adjustment scale that is adjusted according to characteristics such as the thickness of the light beam. For example, δ = 0.1 [rad]
Degree. For example, if f = 10 [Hz] and Vmax = 30 [km / h], θ ≧ about 0.59 [rad] (about 34 degrees), and θ ≦ about 0.79 considering white line detection. [rad] (45 degrees). Considering that smaller θ is better for detecting the white line, for example, θ = 0.59 [rad] (about 34 degrees) can be set.

  The second angle θ is determined by the traveling speed V and the light beam scanning period f. Therefore, the traveling speed can be determined according to the maximum speed Vmax at which traveling control is performed. Therefore, the second angle θ tilted in the vehicle front-rear direction is also determined according to the maximum speed Vmax at which traveling control is performed. Therefore, it is possible to detect a white line that crosses the road, such as a stop line, and it is possible to control traveling at an appropriate timing.

In the second embodiment, since the second angle θ is determined by the scanning period f and the maximum speed Vmax at which travel control is performed, the stop line detection accuracy can be increased at the speed at which travel control is performed.

(Third embodiment)
In the third embodiment, a case will be described in which the direction in which the light beam is tilted in the vehicle front-rear direction (the sign of the second angle θ) is determined by the vehicle traffic classification. The configuration and processing contents of the travel control apparatus according to the third embodiment are the same as those in the first embodiment, and illustration and description thereof are omitted.

  For example, when the traffic segment is on the left side, as shown in FIGS. 7A and 7B, when turning a curve with the same curvature, the left curve turns compared to the right curve. Curvature decreases. Therefore, in the case of the left curve shown in FIG. 7B, if the second angle θ is given in the opposite direction to FIG. 2B, the irradiation position locus rp is as shown by the broken line in FIG. It becomes difficult to cross the center of the lane width. For this reason, the white line cannot be detected. Therefore, if the second angle θ is given to the front of the vehicle in the same direction as FIG. 2B, that is, toward the inside of the traffic section, the locus rp of the irradiation position indicated by the solid line in FIG. It is possible to detect a white line.

As described above, by setting the direction of inclining the light beam in the vehicle width direction according to the traffic classification, it is possible to detect white lines that cross over roads such as stop lines even on curved roads, and it is possible to control traveling at appropriate timing It becomes.

(Fourth embodiment)
In the fourth embodiment, a case where a stop line is detected using two light beams will be described.

  With reference to FIG. 8, the structure of the traveling control apparatus concerning the 4th Embodiment of this invention is demonstrated. The travel control apparatus according to the fourth embodiment further includes a second beam generation unit (second beam generation means) 12 and a second light beam scanning in addition to the components of the travel control apparatus of FIG. A second light receiving unit (second light receiving unit) 22 and a second light receiving unit (second light receiving unit) 22.

  In other words, the travel control device of FIG. 8 has a second beam generation unit 12 that generates a light beam and a light beam generated by the second light beam generation unit 12 mounted on the vehicle. The first angle α is tilted vertically downward and the sign of the second angle θ is changed with respect to the vehicle width direction, that is, a third direction opposite to the front-rear direction tilt of the second angle θ. A second light beam scanning unit 17 that is tilted and fixed in the vehicle longitudinal direction by an angle (−θ) and scans across the center of the lane width, and the reflected light of the light beam reflected on the road ahead of the vehicle And a second light receiving unit 22 for receiving the light.

  The reflected light position calculation unit 25 calculates the position of the reflected light received by the second light receiving unit 22 according to the processing flow shown in FIG. 3 based on the vehicle speed detected by the vehicle speed detection unit 40. (S120). The reflected light position storage unit 30 stores the position of the reflected light received by the second light receiving unit 22 (S120). The white line detection unit 50 detects a white line extending in the vehicle width direction on the road as a stop line based on the position of each reflected light received by the first light receiving unit 20 and the second light receiving unit 22 (S130).

  In addition, the other structure and process content of the traveling control apparatus concerning 4th Embodiment are the same as that of 1st Embodiment, and illustration and description are abbreviate | omitted.

9A and 9B, the locus RP1 of the irradiation position of the light beam by the first light beam scanning unit 15 and the irradiation position of the light beam by the second light beam scanning unit 17 are illustrated. The tracks RP2 cross each other across the center in the vehicle width direction. The second angle θ is opposite to the vehicle width direction. For example, θ ₁ = 0.35 [rad] (about 20 degrees) and θ ₂ = 0.59 [rad] (about 34 degrees).

  In the fourth embodiment, since the two light beams form the second angle θ in opposite directions, it is possible to stably detect and store both the left and right curves. The scan result has a lattice shape, and a stop line or the like can be detected even at a higher speed.

(Other embodiments)
As described above, the present invention has been described in terms of four embodiments. However, it should not be understood that the description and drawings that form part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the embodiment of the present invention, it is described that the vehicle stops when there is a stop line. However, the present invention is applied only when, for example, a temporary stop intersection or red light information is acquired or there is a crossing person or the like. It may be.

Further, by fixing the light beam by giving a yaw angle to the vehicle, it is possible to appropriately recognize the road marking not only at the single road but also at the intersection. The in-vehicle yaw angle is calculated from the length of an object perpendicular to the traveling direction (for example, a white line extending in the vehicle width direction on the road such as a stop line), the maximum speed when the object passes, and the scanning frequency of the light beam. be able to.

10 1st light beam generation part (1st light beam generation means)
12 Second light beam generating section (second light beam generating means)
15 1st light beam scanning part (1st light beam scanning means)
17 Second light beam scanning unit (second light beam scanning means)
20 1st light-receiving part (1st light-receiving means)
22 2nd light-receiving part (2nd light-receiving means)
25 Reflected light position calculating section (reflected light position calculating means)
30 Reflected light position storage unit (reflected light position storage means)
40 Vehicle speed detection unit (vehicle speed detection means)
50 White line detection unit (white line detection means)
60 Travel control unit (travel control means)
α first angle θ second angle

Claims (4)

First beam generating means for generating a light beam mounted on a vehicle;
The light beam generated by the first light beam generating means is tilted vertically downward by a first angle with respect to the front of the vehicle, and tilted in the vehicle front-rear direction by a second angle with respect to the vehicle width direction. First light beam scanning means for fixing and scanning across the center of the lane width;
First light receiving means for receiving reflected light of the light beam reflected on the road ahead of the vehicle;
Vehicle speed detection means for detecting the speed of the vehicle;
Reflected light position calculating means for calculating the position of reflected light received by the first light receiving means based on the speed of the vehicle detected by the vehicle speed detecting means;
Reflected light position storage means for storing the position of the reflected light calculated by the reflected light position calculating means;
A white line detecting means for detecting a white line extending in the vehicle width direction on the road based on the position of the reflected light stored in the reflected light position storage means;
Travel control means for performing travel control of the vehicle based on the white line detected by the white line detection means and the vehicle speed detected by the vehicle speed detection means,
The second angle is determined by a traveling speed and a light beam scanning cycle.   The travel control apparatus according to claim 1, wherein the travel speed is determined based on a maximum speed at which the travel control is performed.   The travel control device according to claim 1 or 2, wherein a direction in which the light beam is tilted in the vehicle width direction is determined by a passage section. A second beam generating means for generating a light beam mounted on the vehicle;
A third light beam generated by the second light beam generating means is tilted vertically downward by the first angle with respect to the front of the vehicle, and the sign of the second angle is changed with respect to the front of the vehicle. A second light beam scanning means that tilts and fixes the vehicle in the vehicle width direction and scans across the center of the lane width;
A second light receiving means for receiving reflected light of the light beam reflected on the road ahead of the vehicle,
The reflected light position calculating means calculates the position of the reflected light received by the second light receiving means based on the speed of the vehicle detected by the vehicle speed detecting means,
The reflected light position storage means stores the position of the reflected light received by the second light receiving means,
The white line detecting means detects a white line extending in a vehicle width direction on a road based on a position of reflected light received by the first light receiving means and the second light receiving means. The travel control device according to any one of?

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