WO2016110731A1

WO2016110731A1 - Forward fixation point distance setting device and travel control device

Info

Publication number: WO2016110731A1
Application number: PCT/IB2015/001079
Authority: WO
Inventors: 正康島影
Original assignee: 日産自動車株式会社
Priority date: 2015-01-05
Filing date: 2015-06-30
Publication date: 2016-07-14
Also published as: JPWO2016110731A1; JP6365688B2

Abstract

A forward fixation point distance setting device (64) which sets a forward fixation point distance (X) for setting a target travel position (TP) ahead of a vehicle on a travel path is equipped with a target forward fixation point distance calculation unit and a forward fixation point distance determination unit. The target forward fixation point distance calculation unit sets a target forward fixation point distance (X1) corresponding to vehicle speed. The forward fixation point distance determination unit sets the forward fixation point distance (X) at a distance shorter than the target forward fixation point distance (X1) if a first distance (X2, X3) from the position of the vehicle to the point of contact tangent to a travel path boundary and/or a second distance (X4, X5) from the position of the vehicle to the point of intersection between the vehicle travel direction and the travel path boundary is shorter than the target forward fixation point distance (X1).

Description

Forward gaze distance setting device and travel control device

The present invention relates to a forward gaze distance setting device and a travel control device. More specifically, the present invention relates to a forward gazing point distance setting device that sets a forward gazing point distance that determines a target traveling position for traveling control, and a traveling control device that includes the forward gazing point distance setting device.

Patent Document 1 discloses a technique for setting a longer forward gazing distance that determines a target travel position for steering control as the amount of offset from the vehicle travel center position increases.
Patent Document 2 discloses a technique for setting a shorter forward gazing distance as the radius of curvature of the traveling path is smaller.

JP 2010-76573 A JP-A-10-167100

However, in the technique described in Patent Document 1, when the offset amount is large with a curve having a small curvature radius, the front gaze distance is set to be long regardless of the curvature radius of the curve, and thus there is a high possibility of lane departure. Become.
On the other hand, in the technique described in Patent Document 2, even if the possibility of lane departure is low, the front gaze distance is always set to be short for a curve with a small radius of curvature, so that the control gain of the steering control becomes too strong. If the behavior changes greatly, the driver feels uncomfortable.
An object of the present invention is to provide a vehicular travel control device capable of achieving both avoidance of approach to a travel path boundary and reduction of uncomfortable feeling given to a driver.

A forward gazing distance setting device as one aspect of the present invention is a device that sets a forward gazing distance for setting a target traveling position on a traveling road ahead of the host vehicle, and a target forward gazing distance calculation unit. And a forward gaze distance determining unit. The target forward gazing distance calculation unit sets a target forward gazing distance according to the vehicle speed. The forward gazing distance determination unit is configured to determine a first distance from a vehicle position to a contact point of a tangent line to the travel route boundary line, and a first distance from the vehicle position to the intersection of the vehicle travel direction and the travel route boundary line. When at least one of the two distances is shorter than the target forward gazing point distance, the front gazing point distance is set to be shorter than the target forward gazing point distance.

The first distance from the own vehicle position to the contact point of the tangent line to the travel path boundary line, or the second distance from the own vehicle position to the intersection of the own vehicle traveling direction and the travel path boundary line is a target corresponding to the vehicle speed. If it is shorter than the forward gazing distance, setting the forward gazing distance to a distance shorter than the target forward gazing distance according to the vehicle speed can avoid the approach to the road boundary line, and in other cases Then, the uncomfortable feeling given to the driver can be reduced without unnecessarily shortening the forward gaze distance.
As a result, it is possible to achieve both the avoidance of approach to the road boundary and the reduction of the uncomfortable feeling given to the driver.

The block diagram which shows the structure of the traveling control apparatus for vehicles which concerns on 1st Embodiment. FIG. 3 is a control block diagram of a control unit of the vehicle travel control apparatus according to the first embodiment. The flowchart which shows the flow of the traveling control process performed with the control unit of the traveling control apparatus for vehicles which concerns on 1st Embodiment. The schematic diagram which shows the calculation method of the contact on the left road boundary line which concerns on 1st Embodiment. The schematic diagram which shows each parameter and control method of the traveling control performed with the control unit of the traveling control apparatus for vehicles which concerns on 1st Embodiment. The flowchart which shows the flow of the traveling control process performed with the control unit of the traveling control apparatus for vehicles which concerns on 2nd Embodiment. The schematic diagram which shows each parameter and control method of the traveling control performed with the control unit of the traveling control apparatus for vehicles which concerns on 2nd Embodiment. The flowchart which shows the flow of the traveling control process performed with the control unit of the traveling control apparatus for vehicles which concerns on 3rd Embodiment. The schematic diagram which shows each parameter and control method of the traveling control performed with the control unit of the traveling control apparatus for vehicles which concerns on 3rd Embodiment.

(1) First embodiment
With reference to FIG. 1, the structure of the traveling control apparatus 10 which concerns on this embodiment is demonstrated. As shown in FIG. 1, the travel control device 10 according to the present embodiment includes a radar 20, a camera 30, a vehicle speed sensor 40, a navigation system 50, a control unit 60, and a travel control actuator 70. Although not shown, a running state sensor that detects the running state of the host vehicle (for example, acceleration, yaw angle, etc.) and the operating state of the host vehicle (accelerator operation, brake operation, steering wheel operation (steering), etc.) The operation state detection sensor which detects this is provided.
The radar 20 detects the presence, position (distance and angle from the host vehicle), speed, and relative speed with respect to the host vehicle. As the radar 20, a laser radar, a millimeter wave radar, or the like can be used. Further, the radar 20 outputs the detected data to the control unit 60. As the radar 20, a well-known radar may be used as appropriate, and therefore a detailed description of the configuration is omitted.
For example, the camera 30 is attached to the front or side of the host vehicle and captures an image around the host vehicle. For example, the camera 30 images a road segment line or an obstacle on the route. The camera 18 includes, for example, an image sensor such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The camera 30 outputs the captured image to the control unit 60. As the camera 30, a well-known camera may be used as appropriate, and thus a detailed description of the configuration is omitted.
The vehicle speed sensor 40 is a sensor that detects the vehicle speed of the host vehicle. Examples of the vehicle speed sensor 40 include a wheel speed sensor that detects the traveling speed of the vehicle by detecting the rotational speed of each wheel of the host vehicle. Further, the vehicle speed sensor 40 outputs the detected speed to the control unit 60. As the vehicle speed sensor 40, a well-known vehicle speed sensor, acceleration sensor, and yaw angle sensor may be used.
The navigation system 50 receives a GPS signal from a GPS (Global Positioning System) satellite. The navigation system 50 also includes a gyroscope that detects the magnitude of the rotational motion applied to the vehicle, an acceleration sensor that detects the travel distance of the vehicle from three-axis acceleration, and a geomagnetic sensor that detects the traveling direction of the vehicle from the geomagnetism. Etc. may be provided. The navigation system 50 stores map information in a recording medium such as a hard disk. This map information includes information on the location and shape of roads and intersections, traffic rules including traffic signs and signals, and the like. Further, the map information may define a travelable area of the vehicle in the lane on the road. The navigation system 50 detects the position of the host vehicle, the direction with respect to the road, and the like based on the GPS signal from the GPS satellite and the map information. The navigation system 50 searches for a route from the departure point to the destination according to the input of the departure point (or current location) and the destination, and uses the searched route and the position information of the own vehicle to reach the destination. The guidance of the route is performed. Further, the navigation system 50 outputs the searched route to the control unit 60 together with the map information. Since a known navigation system may be used as the navigation system 50, a detailed description of the configuration is omitted.
The travel control actuator 70 includes an acceleration / deceleration actuator for accelerating / decelerating the host vehicle and a steering actuator for adjusting a steering angle. The travel control actuator 70 operates the acceleration / deceleration actuator and the steering actuator based on the travel control amount transmitted from the control unit 60 to control the travel of the host vehicle. As the travel control actuator 70, a known travel control actuator may be used, and thus a detailed description of the configuration is omitted.
The control unit 60 performs various calculations based on various information detected by the radar 20, the camera 30, the vehicle speed sensor 40, and the navigation system 50, and sends a control signal corresponding to the calculation result to the travel control actuator 70. By outputting, vehicle steering control (an example of travel control) is performed. In the present embodiment, the control unit 60 is formed as an integrated computer including storage means such as a CPU, RAM, ROM, and hard disk.
As the travel control, the control unit 60 sets a target travel position (front gaze point) separated by a front gaze distance in front of the host vehicle on the travel path so as to travel on the target travel line of the host vehicle. Steering control for driving the left and right front wheels by driving the travel control actuator 70 so that the vehicle travels in the travel position is executed.
FIG. 2 is a control block diagram of the control unit 60 according to the first embodiment. The control unit 60 includes a target travel line setting unit 61, a vehicle speed detection unit 62, a target travel position setting unit 63, a forward gaze distance setting unit 64, and a steering control unit 65, and performs the following travel control. To do.
The target travel line setting unit 61 sets a target route based on the map information obtained from the navigation system 50 and the vehicle position information. Here, the “target route” is different from the concept of a traveling route (direction) from the departure point to the destination set by the navigation system 50. The target route defines how the host vehicle travels on the travel route on the set travel route, that is, the behavior of the vehicle. Information included in the target route includes a target vehicle speed, a target acceleration, a target steering angle, and the like in addition to the target travel line on the travel route.
The vehicle speed detector 62 detects the vehicle speed (vehicle speed) V of the host vehicle based on the signal from the vehicle speed sensor 40. The method for detecting the vehicle speed V is arbitrary. For example, the average value of the wheel speeds of the four wheels and the average value of the wheel speeds of the left and right rear wheels that are driven wheels may be used as the vehicle speed V.
The target travel position setting unit 63 calculates a position on the target travel line that is a distance from the forward gazing point distance X from the host vehicle as the target travel position TP.
The forward gazing point distance setting unit 64 constitutes the forward gazing point distance setting device according to this embodiment, and sets the forward gazing point distance X based on the map information obtained from the navigation system 50 and the vehicle speed V. . That is, the forward gazing point distance setting unit 64 includes a target forward gazing point distance calculation unit and a forward gazing point distance determination unit.
The steering control unit 65 calculates a target curve connecting the host vehicle position and the target travel position TP, calculates a steering control amount for the left and right front wheels based on the target curve, and calculates a travel control actuator based on the calculated steering control amount. 70 is driven.
FIG. 3 is a flowchart showing a flow of a traveling control process executed by the control unit 60 of the traveling control apparatus according to the first embodiment.
Apart from the control flow shown in FIG. 3, the target travel line setting unit 61 sets a target travel line (target route) based on map information and the like. Further, the target travel line may be configured such that the start point to the end point of the route are divided into a plurality of sections and updated for each section as the host vehicle travels along each section.
The control flow shown in FIG. 3 is repeatedly executed at a predetermined interval (for example, 10 to 50 milliseconds) from the start to the end of the travel control of the host vehicle.
In step S11, the forward gazing point distance setting unit 64 reads the left road boundary coordinates and the right road boundary coordinates of the traveling road on which the host vehicle is traveling from the map information acquired from the navigation system 50. Here, the left and right road boundary line coordinates correspond to the coordinates of the left and right boundary lines of the lane that is the travel path on which the host vehicle is traveling. In the present embodiment, a coordinate system in which the reference point (for example, the center point) of the host vehicle is the origin (0, 0), the forward traveling direction of the host vehicle is the x axis, and the left side direction of the host vehicle orthogonal to the y axis is the y axis. The left and right road boundary coordinates are detected.
In step S12, the vehicle speed detection unit 62 reads the vehicle speed V of the host vehicle.
In step S13, the forward gazing point distance setting unit 64 calculates a forward gazing point distance candidate x1 (target forward gazing point distance) based on the vehicle speed V detected in step S12. The process of step S13 in the forward gazing point distance setting unit 64 corresponds to the target forward gazing point distance calculation unit. Here, the forward gazing point distance candidate x1 corresponding to the vehicle speed V is obtained by multiplying the vehicle speed V by a predetermined time constant. Accordingly, the forward gazing point distance candidate x1 corresponding to the vehicle speed is set to a larger value as the vehicle speed is higher, that is, a distance farther from the vehicle.
In step S14, the forward gazing point distance setting unit 64 calculates a forward gazing point distance candidate x2 corresponding to the contact point on the left road boundary line. Here, the contact point on the left road boundary is the tangent drawn from the reference point (for example, the center point) of the own vehicle to the left road boundary within the predetermined distance and the predetermined angle range in front of the own vehicle and the left road boundary. It is a line contact. Depending on the shape of the traveling road, there may be no tangent line within a predetermined distance and a predetermined angle range in front of the host vehicle. Therefore, in step S14, first, it is determined whether a tangent line from the reference point of the host vehicle to the left road boundary line exists within a predetermined distance and a predetermined angle range in front of the host vehicle.
For example, a method of calculating the forward gazing point distance candidate x2 corresponding to the contact point on the left road boundary line in the present embodiment will be described with reference to FIG. First, in a coordinate system in which the reference point of the host vehicle is the origin (0, 0), the forward traveling direction is the positive x-axis direction, and the left side direction of the vehicle is the positive y-axis direction, within a predetermined distance and a predetermined angular range in front of the host vehicle Select n arbitrary points on the left road boundary in the ₁ (X ₁ , Y ₁ ), P ₂ (X ₂ , Y ₂ ) ... P _n (X _n , Y _n ). Here, the predetermined distance range and the predetermined angle range in front of the host vehicle for extracting an arbitrary point are not particularly limited. The predetermined distance range in front of the host vehicle is preferably a distance corresponding to the forward gaze distance candidate x1 corresponding to at least the vehicle speed V set in step S13. That is, the forward gazing point distance setting unit 64 does not have a tangent contact point from the own vehicle position to the traveling road boundary line within a range corresponding to the forward forward gazing point distance candidate x1 from the own vehicle position on the traveling road. In this case, it is determined that the distance (first distance) from the vehicle position to the contact point of the tangent to the road boundary line is equal to or more than the forward gaze distance candidate x1 corresponding to the vehicle speed. In this way, by limiting the range for determining whether or not a contact exists to a range within the distance corresponding to the forward gazing point distance candidate x1, it is possible to start from the vehicle position to the road boundary without performing unnecessary calculation processing. It can be determined whether the distance (first distance) to the contact point of the tangent to the line is shorter than the forward gazing point distance candidate x1 corresponding to the vehicle speed. The predetermined angle range in front of the host vehicle can be, for example, an angle range of 180 ° on the vehicle front side from the left lateral direction to the right lateral direction of the vehicle centering on the reference point of the host vehicle. In the example of FIG. 4, the point P on the left road boundary line within the distance of the forward gazing point distance candidate x1 corresponding to the vehicle speed V from the own vehicle from the left lateral direction (y axis positive direction) of the own vehicle. ₁ ~ P ₇ Select and point P ₁ ~ P ₇ Are obtained in order. And the reference point (origin (0, 0)) of the host vehicle and each point P ₁ ~ P _n For each straight line passing through, the slope m with respect to the vehicle traveling direction (x-axis) _n (Tan θ _n = Y _n / X _n ) Is calculated. If it is possible to draw a tangent line from the reference point of the vehicle to the left road boundary, this slope m _n Decreases as the distance from the host vehicle decreases, reaches a minimum value at a contact point or a point P in the vicinity of the contact point, and then increases as the position of the point further moves away from the host vehicle. Therefore, a plurality of points P ₁ ~ P _n Of the points P corresponding to this change point (minimum value) _min A straight line passing through the vehicle is regarded as a tangent line from the reference point (origin point) of the host vehicle to the left road boundary line. _min Is regarded as a contact point P on the left road boundary line. That is, the “contact” used in this specification includes not only a true contact but also an approximate value of the contact and a value according to the contact. In the example of FIG. ₁ To point P ₅ The slope of the straight line becomes smaller toward ₅ To minimize the slope. And point P ₅ To point P ₇ The slope of the straight line increases toward. Therefore, in the example of FIG. ₅ Is the change point (minimum value), and this point P ₅ Can be regarded as a contact point P on the left road boundary line. And point P ₅ Is set as the forward gazing point distance candidate x2.
Here, the number (n) of points P extracted to determine whether a tangent line exists is not particularly limited as long as it is a number that can identify the change point of the slope. For example, about 8 to 12 are preferable, and at most about several tens.
The method for determining whether a tangent exists and the method for calculating the tangent / contact are not limited to the above-described methods, and any known tangent or contact detection method such as a calculation by a differential method can be used.
If no tangent exists in step S14, the forward gazing point distance candidate x2 has a null value. For example, when the traveling road within a predetermined distance and a predetermined angle range ahead of the host vehicle is a straight road, there is no tangent to the left / right road boundary line. In addition, when there are multiple tangents and contacts to the left road boundary line within the predetermined distance range and the predetermined angle range in front of the vehicle, the coordinates of the contact point closest to the host vehicle among the multiple contact points are used. Let the corresponding distance be a forward gaze distance candidate x2.
In step S15, as in step S14, the forward gazing point distance setting unit 64 calculates a forward gazing point distance candidate x3 corresponding to the contact point on the right road boundary line. When the contact point calculation method shown in FIG. 4 is applied, since the sign of the y coordinate is negative for the point on the right road boundary line, the changing point at which the inclination is maximum is specified. Since other processes are the same as those in step S14, description thereof is omitted.
In step S16, the forward gaze distance setting unit 64 sets the minimum value among the forward gaze distance candidates x1, x2, and x3 obtained in steps S13 to S15 as the front gaze distance X. The process of step S16 in the forward gazing point distance setting unit 64 corresponds to the forward gazing point distance determination unit. That is, the forward gazing point distance setting unit 64 has a distance x2 from the own vehicle position to the contact point of the tangent line to the left traveling road boundary line and a distance x3 from the own vehicle position to the contact point of the tangent line to the right traveling road boundary line. The shorter one is the distance (first distance) from the vehicle position to the contact point of the tangent to the road boundary line, and the first distance is a forward gazing point distance candidate x1 (target forward gazing point distance) corresponding to the vehicle speed. Is shorter than the forward gazing point distance candidate x1 corresponding to the vehicle speed. In the present embodiment, the front gazing point distance setting unit 64 sets the front gazing point distance to a distance corresponding to the first distance when the first distance is shorter than the target front gazing point distance.
In step S17, the target travel position setting unit 63 calculates, as the target travel position TP, a position on the target travel line that is away from the front gaze distance X from the host vehicle based on the front gaze distance X set in step S16. To do. In this embodiment, the reference point of the host vehicle is the origin (0, 0), the forward traveling direction is the x-axis positive direction, and the left side of the vehicle is the y-axis positive direction. The target travel position TP is calculated by substituting the value of the x coordinate into a function indicating the target travel line. For example, when the target travel line is defined as a function passing through the center of the left boundary line and the right boundary line, the target travel position TP can be obtained by substituting the value of the x coordinate into this function. However, the method for calculating the target travel position TP corresponding to the forward gazing point distance X is not limited to this method. For example, a perpendicular line may be drawn from the contact point P to the target travel line, and the intersection of the target travel line and the perpendicular line may be determined as the target travel position TP, or forward from the reference point in the forward traveling direction of the vehicle (on the x axis). A perpendicular line may be drawn to the target travel line from a point separated by the gazing point distance X (point of coordinates (X, 0)), and the intersection of the target travel line and the perpendicular may be determined as the target travel position TP.
In step S18, the steering control unit 65 calculates a target curve that connects the host vehicle position and the target travel position TP with a constant curvature, and calculates a steering control amount for the left and right front wheels according to the target curve. Then, the travel control actuator 70 is driven based on the calculated steering control amount. At this time, the steering control amount that passes on the target curve may be calculated, but a torque sensor is provided on the steering shaft to detect the driver's steering intervention, and at the time of steering intervention, the steering control amount is set to zero, A steering torque that guides the driver's steering operation to the turning angle of the left and right front wheels that pass on the target curve may be applied.
FIG. 5 shows the vehicle position, the target travel line, the left / right road boundary line, the contact point P on the left road boundary line, the forward gazing point distance candidate x1 corresponding to the vehicle speed V, and the contact point P in the travel control of the first embodiment. The corresponding forward gazing point distance candidate x2, the forward gazing point distance X, the target travel position TP, and the target curve are shown. In the example shown in FIG. 5, since there is no tangent to the right road boundary within a predetermined range in front of the vehicle, there is no forward gazing distance candidate x3 corresponding to the contact point on the right road boundary.
FIG. 5 shows a case where the host vehicle enters a curve closer to the host vehicle when the road shape is a compound curve (such as an S-shape). If the target travel position TP ′ is set with the forward gazing point distance candidate x1 corresponding to the vehicle speed V as the forward gazing point distance when the shape of the road is a compound curve, the vehicle is far away from the host vehicle as seen in FIG. The target travel position TP ′ may be set as the position. In such a case, the target curve to the target travel position target travel position TP ′ becomes a curve that is a shortcut to the curve, and the host vehicle may be too close to the left road boundary line.
In the present embodiment, the contact point P on the left road boundary line is detected, and when the forward gazing point distance candidate x2 corresponding to the contact point P is shorter than the forward gazing point distance candidate x1 corresponding to the vehicle speed V, the contact point P is determined. The corresponding forward gazing point distance candidate x2 is set as the forward gazing point distance X. As a result, as shown in FIG. 5, the target travel position TP is set at a position closer to the host vehicle as compared with the target travel position TP ′ based on the forward gazing distance candidate x1 corresponding to the vehicle speed V. Therefore, the target curve is a curve toward the target travel position TP set at a position close to the host vehicle, and the host vehicle can avoid being too close to the left road boundary line. That is, when the distance to the nearest convex part of the curve in front of the vehicle is closer, the distance from the own vehicle to the contact point of the tangent to this convex part (the forward gazing point distance candidate x2 in the example of FIG. 5) is the vehicle speed. It becomes shorter than the forward gazing point distance candidate x1 according to V. Therefore, the forward gazing point distance X is set to a value smaller than the forward gazing point distance candidate x1 corresponding to the vehicle speed V, and the traveling position of the vehicle can be controlled so as not to approach the nearest convex portion. On the other hand, when there is no contact (when there is no convex part of the curve in the vicinity), setting the forward gaze distance according to the vehicle speed V prevents the control gain from becoming unnecessarily large, and changes the vehicle behavior. Can be suppressed. As a result, it is possible to achieve both the avoidance of approach to the road boundary and the reduction of the uncomfortable feeling given to the driver.
In the travel control device of the present embodiment, when traveling on a curve having a small radius of curvature or a shape that shifts from a straight line to a curve having a small radius of curvature, the distance to the front gazing point according to the vehicle speed V is set. Even if the target travel position is set based on the curve, the front gaze distance can be shortened more than the front gaze distance according to the vehicle speed V, and the vehicle travel position can be controlled to perform the shortcut. The trend can be improved. As a result, it is possible to more reliably achieve both avoidance of approach to the road boundary and reduction of the uncomfortable feeling given to the driver.
Further, in the travel control device of the present embodiment, there is no need to determine the shape of the travel path on which the host vehicle is traveling, the posture angle of the host vehicle, its orientation, lateral displacement, etc., and the left and right roads Only by detecting the contact point of each road boundary line based on the information on the boundary line, there is an effect that it is possible to perform traveling control that can avoid the approach to the road boundary and reduce the uncomfortable feeling given to the driver.
(2) Second embodiment
The device configuration of the travel control device 10 according to the second embodiment is the same as the configuration of the travel control device 10 according to the first embodiment shown in FIGS. In the second embodiment, a part of the traveling control process executed in the control unit 60 is different from the traveling control process of the first embodiment.
FIG. 6 is a flowchart showing a flow of travel control processing executed by the control unit 60 of the vehicle travel control apparatus according to the second embodiment.
Similar to the first embodiment, also in the second embodiment, a target travel line (target route) is set based on map information or the like in the target travel line setting unit 61 separately from the control flow shown in FIG.
The control flow shown in FIG. 6 is repeatedly executed at a predetermined interval (for example, 10 to 50 milliseconds) from the start to the end of the travel control of the host vehicle.
The processing from step S21 to S23 is the same as the processing from step S11 to S13 in FIG.
In step S24, the forward gazing point distance setting unit 64 calculates a forward gazing point distance candidate x4 corresponding to the intersection of the own vehicle traveling direction and the left road boundary line within a predetermined distance ahead of the own vehicle. Here, there may be no intersection between the traveling direction of the vehicle and the left road boundary. When there is no intersection, x4 is a null value. When there are a plurality of intersections within the predetermined distance range, the distance corresponding to the intersection closest to the host vehicle is set as the forward gaze distance candidate x4. Here, the predetermined distance range in front of the host vehicle for detecting the intersection is not particularly limited. The predetermined distance range ahead of the host vehicle is preferably a distance range corresponding to the forward gaze distance candidate x1 corresponding to the vehicle speed V set in step S23. That is, the forward gazing point distance setting unit 64 determines that the intersection of the traveling direction and the traveling road boundary line from the own vehicle position within the range corresponding to the forward forward gazing point distance candidate x1 from the own vehicle position on the traveling road. If it does not exist, it is determined that the distance (second distance) from the own vehicle position to the intersection of the own vehicle traveling direction and the travel path boundary line is not less than the forward gazing distance candidate x1 corresponding to the vehicle speed. In this way, by limiting the range for determining whether or not there is an intersection to the range within the distance corresponding to the forward gazing point distance candidate x1, the vehicle progresses from the vehicle position without performing unnecessary calculation processing. It is possible to determine whether the distance (second distance) to the intersection of the direction and the road boundary line is shorter than the forward gazing point distance candidate x1 according to the vehicle speed.
In the present embodiment, in accordance with the vehicle speed V from the own vehicle in a coordinate system in which the reference point of the own vehicle is the origin (0, 0), the forward traveling direction is the x-axis positive direction, and the left side direction of the vehicle is the y-axis positive direction The coordinates of the intersection C (x, y) of the left road boundary line and the x axis are detected within the range up to the forward gazing point distance candidate x1. The distance from the host vehicle to this intersection C is set as a forward gazing point distance candidate x4.
In step S25, as in step S24, the forward gazing point distance setting unit 64 calculates a forward gazing point distance candidate x5 corresponding to the intersection of the vehicle traveling direction and the left road boundary within a predetermined distance ahead of the host vehicle. To do.
In step S26, the forward gazing point distance setting unit 64 sets the minimum value among the forward gazing point distance candidates x1, x4, and x5 obtained in steps S23 to S25 as the forward gazing point distance X. The process of step S26 in the forward gaze distance setting unit 64 corresponds to the front gaze distance determination unit. That is, the forward gazing point distance setting unit 64 determines that the distance (second distance) from the own vehicle position to the intersection of the own vehicle traveling direction and the road boundary line is a forward gazing point distance candidate x1 (target forward gazing point) corresponding to the vehicle speed. If it is shorter than (viewpoint distance), the forward gazing point distance is set to a distance shorter than the forward gazing point distance candidate x1 according to the vehicle speed. In the present embodiment, the forward gazing point distance setting unit 64 sets the forward gazing point distance to a distance corresponding to the second distance when the second distance is shorter than the target forward gazing point distance.
Since the processes of steps S27 and S28 are the same as the processes of steps S17 and S18 of FIG. 3 of the first embodiment, a description thereof will be omitted.
FIG. 6 shows the vehicle position, the target travel line, the left / right road boundary line, the intersection C between the vehicle traveling direction and the right road boundary, and the forward gazing distance according to the vehicle speed V in the travel control of the second embodiment. The candidate x1, the forward gazing point distance candidate x5 corresponding to the intersection C, the forward gazing point distance X, the target travel position TP, and the target curve are shown. In the example shown in FIG. 6, since there is no intersection between the traveling direction of the own vehicle and the left road boundary within a predetermined range in front of the vehicle, the forward gaze point corresponding to the intersection of the traveling direction of the own vehicle and the left road boundary There is no distance candidate x4.
As shown in FIG. 6, when the vehicle is traveling toward the outside of the curved road, if the front gazing point distance is set according to the vehicle speed V, the target travel position TP ′ is far away from the host vehicle. The target curve tends to go round, and may be too close to the outer boundary.
In this embodiment, as shown in FIG. 6, there is an intersection C between the traveling direction of the vehicle and the road boundary line (the right road boundary line in the example of FIG. 6) within a predetermined distance in front of the vehicle. When the distance from the vehicle to the intersection C (front gaze distance candidate x5) is smaller than the front gaze distance candidate x1 according to the vehicle speed V, the front gaze distance is greater than the front gaze distance candidate x1 according to the vehicle speed V. Is also set short. Specifically, the forward gazing point distance candidate x5 corresponding to the intersection C with the right road boundary line is set as the forward gazing point distance X. As a result, the forward gaze distance is corrected to a smaller value as the vehicle is directed to the outside of the road, and the follow-up speed to the target travel line is increased. According to the travel control according to the present embodiment, when the road shape changes greatly, for example, when the curve changes from a curve with a small radius of curvature to a straight line or when the road shape changes from a straight line to a curve with a small radius of curvature. Since the front gaze distance becomes shorter than the front gaze distance, the response speed can be temporarily increased. On the other hand, when there is no intersection within the predetermined distance range (when the host vehicle is not facing the outside of the travel path), the control gain is unnecessarily increased by setting the forward gazing distance according to the vehicle speed V. This can prevent changes in vehicle behavior. As a result, it is possible to achieve both the avoidance of approach to the road boundary and the reduction of the uncomfortable feeling given to the driver.
Further, in the travel control device of the present embodiment, as shown in FIG. 6, when traveling on a travel path having a shape that shifts from a curve with a small radius of curvature to a straight line, a forward note corresponding to the vehicle speed V is used. When the target travel position is set based on the viewpoint distance, the forward gazing distance can be shortened more than the forward gazing distance according to the vehicle speed V in the case where the target travel position becomes too large and the outer boundary line is approached too much. The traveling position of the vehicle can be controlled to improve the tendency to turn around. As a result, it is possible to more reliably achieve both avoidance of approach to the road boundary and reduction of the uncomfortable feeling given to the driver.
Further, in the travel control device of the present embodiment, there is no need to determine the shape of the travel path on which the host vehicle is traveling, the posture angle of the host vehicle, its orientation, lateral displacement, etc., and the left and right roads Only by detecting the intersection of the vehicle traveling direction and each road boundary line based on the information on the boundary line, it is possible to perform driving control compatible with avoidance of approaching the road boundary and reduction of uncomfortable feeling given to the driver. effective.
(3) Third embodiment
The device configuration of the travel control device 10 according to the third embodiment is the same as the configuration of the travel control device 10 according to the first embodiment shown in FIGS. In the third embodiment, the traveling control process executed in the control unit 60 is different from the traveling control process of the first embodiment or the second embodiment. That is, in the third embodiment, the distance from the own vehicle position to the contact point of the tangent line to the travel path boundary line (first distance), the distance from the own vehicle position to the intersection of the own vehicle traveling direction and the travel path boundary line. The forward gazing point distance is set to a distance corresponding to the minimum value among the (second distance) and the forward gazing point distance (target forward gazing point distance) according to the vehicle speed. Specifically, in the third embodiment, the forward gazing point distance candidate (x2, x3) corresponding to the contact point on the road boundary line of the first embodiment, the own vehicle traveling direction and the road boundary line of the second embodiment. Both the forward gazing point distance candidates (x4, x5) corresponding to the intersection with the forward gazing point distance candidates (x2, x3, x4, x5) and the forward gazing point distance candidates corresponding to the vehicle speed V ( The minimum value of x1) is set as the forward gaze distance X.
FIG. 8 is a flowchart showing a flow of a travel control process executed by the control unit 60 of the vehicle travel control apparatus according to the third embodiment.
Similar to the first and second embodiments, in the third embodiment, the target travel line (route information) is set based on the map information and the like in the target travel line setting unit 61 separately from the control flow shown in FIG. Is done.
The control flow shown in FIG. 8 is repeatedly executed at predetermined intervals (for example, 10 to 50 milliseconds) from the start to the end of the travel control of the host vehicle.
The processing from step S31 to S35 is the same as the processing from step S11 to S15 in FIG.
Since the processes of steps S36 and S37 are the same as the processes of steps S24 and S25 of FIG. 6 of the second embodiment, description thereof will be omitted.
In step S38, the forward gaze distance setting unit 64 sets the minimum value among the forward gaze distance candidates x1 to x5 obtained in steps S32 to S37 as the front gaze distance X.
Since the processes of steps S39 and S40 are the same as the processes of steps S17 and S18 of FIG. 3 of the first embodiment, description thereof will be omitted.
FIG. 9 shows the own vehicle position, target travel line, left / right road boundary line, contact point P on the left road boundary line, intersection C between the traveling direction of the own vehicle and the right road boundary line, vehicle speed in the travel control of the third embodiment. A forward gazing point distance candidate x1 corresponding to V, a forward gazing point distance candidate x2 corresponding to the contact point P, a forward gazing point distance candidate x5 corresponding to the intersection C, the forward gazing point distance X, and the target travel position TP are shown. In the example shown in FIG. 9, there is no tangent to the right road boundary line within the predetermined range in front of the vehicle and the intersection of the traveling direction of the own vehicle and the left road boundary line, so that it corresponds to a contact point on the right road boundary line. There is no forward gazing point distance candidate x3 corresponding to the intersection of the forward gazing point distance candidate x3, the traveling direction of the own vehicle, and the left road boundary line.
In the example shown in FIG. 9, the tangent line from the reference point of the host vehicle to the left road boundary line within a predetermined distance range in front of the vehicle (in this example, the range up to the forward gazing point distance candidate x1 according to the vehicle speed V). This is a case where there is an intersection C between the contact point P of the vehicle and the traveling direction of the vehicle and the right road boundary line. In such a case, a forward gazing point distance candidate x1 corresponding to the vehicle speed V, a forward gazing point distance candidate x2 corresponding to the contact point P on the left road boundary line, and the intersection C between the vehicle traveling direction and the right road boundary line The forward gazing point distance candidate x2 corresponding to the contact point P which is the minimum value among the forward gazing point distance candidates x5 corresponding to is set as the forward gazing point distance X. Accordingly, as shown in FIG. 9, the forward gazing distance corresponding to the target traveling position TP ′ based on the forward gazing distance candidate x1 corresponding to the vehicle speed V and the intersection C between the own vehicle traveling direction and the right road boundary line. Compared with the target travel position TP ″ based on the candidate x5, the target travel position TP is set at a position closer to the own vehicle. Therefore, the target curve is a curve toward the target travel position TP set at a position close to the own vehicle. It is possible to avoid that the host vehicle is too close to the left road boundary line.
Further, in this embodiment, when the host vehicle is facing the outside of the road, the forward gazing distance is corrected to a small value based on the intersection C between the host vehicle traveling direction and the outer road boundary line, and the target travel The speed of following the line is increased, and approach to the outer road boundary line can be avoided. As in this embodiment, by detecting both the contact point on the road boundary line, the traveling direction, and the intersection of the road boundary line and performing the traveling control, avoiding the approach to the traveling road boundary and the driver on the traveling road of various shapes It is possible to more surely achieve a balance with the reduction of the uncomfortable feeling given to the user.
Although the travel control device and the travel control of the present invention have been described in detail above, the present invention is not limited to the above embodiment. It goes without saying that various improvements and modifications may be made without departing from the spirit of the present invention.
For example, in the first to third embodiments, the left / right road boundary line information is obtained from the map information of the navigation system 50. However, the present invention is not limited to this configuration. For example, the left and right road boundary lines may be detected by actually detecting road / lane boundaries, curbs, road lane markings, and the like from the detection results of the radar 20 and the captured image obtained from the camera 30. good. Alternatively, if the left and right road boundary information cannot be obtained from the map information or radar / camera detection results, or if there is no boundary line such as a parking lot, a virtual boundary line can be set and It is also possible to perform the travel control of the first to third embodiments.
In the first to third embodiments, the forward gazing point distance X is set to the minimum value among the forward gazing point distance candidates x1 to x5, but is not limited to this configuration. That is, at least one of the forward gazing point distance candidates x2 and x3 corresponding to the contact point P on the road boundary line and the forward gazing point distance candidates x4 and x5 corresponding to the intersection C between the own vehicle traveling direction and the road boundary line becomes the vehicle speed V. The forward gazing point distance X may be set to a shorter distance than the forward gazing point distance candidate x1 corresponding to the vehicle speed V when it is smaller than the corresponding forward gazing point distance candidate x1. Therefore, it is not always necessary to set the forward gazing point distance X based on the position of the contact point P or the intersection C or the distance from the host vehicle. For example, when at least one of the forward gaze distance candidates x2 and x3 corresponding to the contact point P and the forward gaze distance candidates x4 and x5 corresponding to the intersection C is smaller than the forward gaze distance candidate x1 corresponding to the vehicle speed V The forward gazing point distance X may be set to a value obtained by shortening the forward gazing point distance candidate x1 corresponding to the vehicle speed V by a predetermined distance. That is, the forward gazing point distance setting unit 64 intersects the distance (first distance) from the own vehicle position to the contact point of the tangent to the travel path boundary line, the intersection of the own vehicle traveling direction and the travel path boundary line from the own vehicle position. If at least one of the distance to the distance (second distance) is shorter than the forward gazing distance according to the vehicle speed (target forward gazing distance), a predetermined distance is subtracted from the forward gazing distance according to the vehicle speed The distance obtained in this way can be set as the forward gaze distance. Thereby, arithmetic processing can be simplified more. In this case, the predetermined distance can be made variable based on the magnitude of the vehicle speed V, or the front gaze distance candidate x1 corresponding to the vehicle speed V and the front gaze distance candidate x2, x3 corresponding to the contact point P or the intersection C can be handled. The predetermined distance may be variable based on the deviation from the forward gazing point distance candidates x4 and x5.
In the first to third embodiments, an example is described in which a coordinate system is used in which the reference point of the host vehicle is the origin (0, 0), the forward traveling direction is the x-axis positive direction, and the left side of the vehicle is the y-axis positive direction. However, the present invention is not limited to this configuration. For example, a coordinate system based on the target travel line can be used.

DESCRIPTION OF SYMBOLS 10 Travel control apparatus 20 Radar 30 Camera 40 Vehicle speed sensor 50 Navigation system 60 Control unit 70 Travel control actuator 61 Target travel line setting part 62 Vehicle speed detection part 63 Target travel position setting part 64 Front gaze distance setting part 65 Steering control part

Claims

A forward gazing distance setting device for setting a forward gazing distance for setting a target traveling position on a traveling road ahead of the host vehicle,
A target forward gazing distance calculation unit for setting a target forward gazing distance according to the vehicle speed;
At least one of the first distance from the own vehicle position to the contact point of the tangent line to the traveling road boundary line and the second distance from the own vehicle position to the intersection of the own vehicle traveling direction and the traveling road boundary line is A forward gazing point distance determining unit configured to set the forward gazing point distance to a distance shorter than the target forward gazing point distance when shorter than the target forward gazing point distance. Setting device.
The front gaze distance determination unit determines the front gaze distance as the first distance when at least one of the first distance and the second distance is shorter than the target front gaze distance. The forward gaze distance setting device according to claim 1, wherein the distance is set to a distance corresponding to at least one of the second distance and the second distance.
The front gazing point distance determination unit sets the front gazing point distance to a distance corresponding to the first distance when the first distance is shorter than the target front gazing point distance. The forward gaze distance setting device according to claim 1.
The forward gazing point distance determination unit sets the forward gazing point distance to a distance corresponding to the second distance when the second distance is shorter than the target forward gazing point distance. The forward gaze distance setting device according to claim 1.
The front gaze distance determination unit sets the front gaze distance to a distance corresponding to a minimum value among the first distance, the second distance, and the target front gaze distance. The forward gaze distance setting device according to claim 1.
The forward gazing distance determination unit is the shorter of the distance from the vehicle position to the contact point of the tangent line to the left road boundary line and the distance from the vehicle position to the contact point of the tangent line to the right road boundary line The forward gaze distance setting device according to claim 1, wherein the first distance is set as the first distance.
When the forward gazing point distance determination unit does not have the contact point of the tangent line from the own vehicle position to the traveling road boundary line within a range within the target gazing point distance ahead of the own vehicle position on the traveling road. 7. The forward gaze distance setting according to claim 1, wherein the first distance is determined to be greater than or equal to the target gaze distance. 8. apparatus.
The forward gazing distance determination unit includes the intersection of the traveling direction and the traveling road boundary line from the own vehicle position within a range within the target gazing distance ahead of the own vehicle position on the traveling road. If not, it is determined that the second distance is greater than or equal to the target gazing distance. 8. The forward gazing point according to any one of claims 1, 2, and 4 to 7. Distance setting device.
The front gaze distance determination unit subtracts a predetermined distance from the target front gaze distance when at least one of the first distance and the second distance is shorter than the target front gaze distance The front gaze distance setting device according to claim 1, wherein the distance obtained by setting the distance to the front gaze distance is set.
The front gaze distance setting device according to claim 9, wherein the front gaze distance determination unit variably sets the predetermined distance.