JP7532240B2 - Driving support method and driving support device - Google Patents

Description

The present invention relates to a driving assistance method and a driving assistance device.

A technology is known that generates a target route for the vehicle, detects a forward stopping position on the target route in a specified situation, and corrects the stopping position of the vehicle from the forward stopping position to a target stopping position where the vehicle assumes a posture suited to the specified situation (Patent Document 1).

For example, when setting a stopping position for the vehicle to cross an oncoming lane, the technology of Patent Document 1 detects the intersection of the target route and the boundary between the vehicle's lane and the oncoming lane as the forward stopping position, and sets the target stopping position to a position on the target route before the forward stopping position where the vehicle is parallel to the boundary.

International Publication No. 2016/189649

However, when the vehicle crosses the oncoming lane, the target route curves toward the stop position ahead, so the position where the vehicle traveling along the target route is parallel to the boundary line is away from the stop position ahead due to the curved section. Therefore, with the technology of Patent Document 1, the target stop position is set at a position away from the stop position ahead by the curve section, which causes a problem that it takes a long time for the vehicle to cross the oncoming lane from the target stop position.

The problem that the present invention aims to solve is to provide a driving assistance method and device that can shorten the time it takes for a vehicle to cross an oncoming lane from a stopped position.

The present invention is a driving assistance method that generates a driving route for the vehicle, detects an intersection scene where the driving route intersects with another lane that is traveling in a different direction from the lane in which the vehicle is traveling, and sets a target stop position on the driving route at the intersection scene where the vehicle will stop before crossing the boundary line between the vehicle's lane and the other lane.The above problem is solved by setting the target stop position for the vehicle at a position on the driving route that is not included in an area where another vehicle traveling in the other lane may pass, and where the direction of the driving route at the position is at an angle to the boundary line.

The present invention can reduce the time it takes for a vehicle to cross the oncoming lane from its stopped position.

1 is a diagram showing a hardware configuration of a vehicle to which a driving assistance device and method according to an embodiment of the present invention are applied. FIG. 2 is a diagram showing an example of a functional block diagram of a driving support device according to the present embodiment. 5A to 5C are diagrams illustrating an example of a method for setting a target stop position according to the embodiment. 5A to 5C are diagrams illustrating an example of a method for setting a target stop position according to the embodiment. 5A to 5C are diagrams illustrating an example of a method for setting a target stop position according to the embodiment. 5A to 5C are diagrams illustrating an example of a method for setting a target stop position according to the embodiment. 5 is a flowchart for explaining a control procedure for setting a target stop position according to the present embodiment.

The following describes an embodiment of the present invention with reference to the drawings. The vehicle driving assistance device according to the following embodiment is a device for setting a stopping position of the vehicle in a vehicle driving control for automatically driving or assisted driving of the vehicle according to a driving route. The automatic driving or driving assistance of the vehicle in this embodiment is started according to the driver's input, and the vehicle is driven according to the driving route even without the driver's accelerator, brake, or steering operation. However, when the driver operates the accelerator, brake, or steering, the automatic driving control or driving assistance control is stopped or temporarily interrupted, and various operations by the driver are given priority.

Figure 1 is a plan view showing the hardware configuration of a host vehicle 1 to which a driving assistance device 100 according to this embodiment is applied. As shown in Figure 1, the host vehicle 1 includes a GPS (Global Positioning System) receiver 2, a navigation unit 3, a vehicle speed sensor 4, the driving assistance device 100, a powertrain controller 6, an engine and drive system 7, a brake controller 8, a brake unit 9, a yaw rate sensor 10, an acceleration sensor 11, a camera 12, and a steering motor controller 13.

The GPS receiver 2 receives a GPS signal related to the absolute position coordinates (latitude and longitude) of the vehicle 1 and transmits the received signal to the navigation unit 3 and the driving support device 100. The navigation unit 3 includes a map database 5 (see FIG. 2), an information processing device, and a display device. The map database 5 also includes information related to the road structure of the roads on the map. The road structure includes the shape of the lanes, the number of lanes, the width of the lanes, and the presence or absence of guidance zones, so-called zebra zones, on the lanes. In the navigation unit 3, when a destination is set by the occupant, the information processing device sets a driving route from the current location to the destination and displays it on the display device. The information processing device also transmits driving route information to the driving support device 100.

The vehicle speed sensor 4 measures the vehicle speed of the vehicle 1 and transmits a measurement signal to the driving support device 100. A rotary encoder attached to the wheel can be used as the vehicle speed sensor 4. The rotary encoder measures the vehicle speed based on a pulse signal generated in proportion to the number of rotations of the wheel.

The driving support device 100 is an integrated circuit such as a microprocessor, and includes an A/D conversion circuit, a D/A conversion circuit, a central processing unit (CPU), a ROM (Read Only Memory), and a RAM (Read Access Memory). The driving support device 100 processes information input from sensors such as an accelerator pedal sensor and a brake pedal sensor according to a program stored in the ROM to calculate a target vehicle speed, transmits a required driving force according to the target vehicle speed to the powertrain controller 6, and transmits a required braking force according to the target vehicle speed to the brake controller 8. The driving support device 100 also processes steering angle information input from a steering angle sensor according to a program stored in the ROM to calculate a target steering angle, and transmits a steering amount according to the target steering angle to the steering motor controller 13.

The powertrain controller 6 controls the engine and drive system 7 to realize the required driving force transmitted from the driving assistance device 100. Although a vehicle equipped with only an engine (internal combustion engine) as a driving source has been given as an example, the present invention may also be applied to electric vehicles (including fuel cell vehicles) that use only an electric motor as a driving source, or hybrid vehicles that use a combination of an engine and an electric motor as a driving source.

The brake controller 8 controls the brake units 9 provided on the wheels to realize the required braking force transmitted from the driving support device 100. The steering motor controller 13 controls the steering motor (not shown) of the steering mechanism to realize the target steering angle transmitted from the driving support device 100. The steering motor is a steering actuator attached to the steering column shaft.

The yaw rate sensor 10 measures the yaw rate of the vehicle 1 and outputs a measurement signal to the driving support device 100. The acceleration sensor 11 measures the acceleration of the vehicle 1 and outputs a measurement signal to the driving support device 100.

The camera 12 is an imaging device equipped with an imaging element such as a CCD, and is installed at the front of the vehicle 1 to capture an image of the area ahead of the vehicle 1 to obtain image data. The external information recognition unit 14 uses image processing to calculate the positions of objects such as other vehicles and curbs ahead of the vehicle 1, the presence and position of lane boundaries and road markings on the road, the speed of moving objects such as other vehicles, and the like, from the image data obtained by the camera 12, and outputs the information to the driving support device 100.

Figure 2 is a functional block diagram of the driving support device 100. As shown in Figure 2, the processor 110 includes a route generation unit 101, a detection unit 105, and a position setting unit 106. The route generation unit 101 includes a driving route generation unit 102, a target speed generation unit 103, and a steering target generation unit 104. The position setting unit 106 includes an intersection extraction unit 107, a normal line setting unit 108, and a position determination unit 109.

The route generating unit 101 receives driving route information from the navigation unit 3 and map information from the map database 5. The route generating unit 101 also receives absolute position information of the vehicle 1 from the GPS 2 and information such as the position and speed of objects such as other vehicles ahead of the vehicle from the external information recognition unit 14. Based on the input information, the route generating unit 101 generates a driving route for the vehicle 1 by the driving route generating unit 102. Specifically, the driving route generating unit 102 generates a driving route that passes through the center of the lane along the driving route from the position of the vehicle on the map. If an obstacle exists on the driving route, the driving route generating unit 102 generates a driving route that avoids the obstacle. The route generating unit 101 also receives vehicle speed information of the vehicle 1 from the vehicle speed sensor 4, yaw rate information of the vehicle from the yaw rate sensor 10, and acceleration information of the vehicle from the acceleration sensor 11. The target speed generating unit 103 generates a target speed of the vehicle traveling along the driving route. For example, when a target stop position is set by the position setting unit 106, the target speed generating unit 103 generates a target speed so that the host vehicle can stop at the target stop position. Specifically, the target speed generating unit 103 creates a profile such that the target speed becomes 0 m/s at the target stop position when the host vehicle is decelerated at a predetermined deceleration. The target speed generating unit 103 transmits the target speed to the powertrain controller 6 and the brake controller 8. In addition, the steering target generating unit 104 calculates a steering target for making the host vehicle 1 follow the generated driving path, and outputs the steering target to the steering motor controller 13.

The detection unit 105 detects an intersection scene where the driving route intersects with another lane located ahead of the vehicle 1 in the traveling direction. The other lane is a lane in a different traveling direction from the lane in which the vehicle 1 is traveling. The other lane is, for example, an oncoming lane adjacent to the vehicle lane. In addition, the other lane is a priority road when the vehicle lane is a non-priority road that merges with a priority road. Examples of intersection scenes include a scene where the driving route intersects with another lane that is an oncoming lane, and a scene where a driving route passing through the vehicle lane that is a non-priority road merges with the other lane that is a priority road at a T-junction. An example of an intersection scene where the driving route intersects with the oncoming lane is a scene where the vehicle 1 traveling in the vehicle lane turns right and crosses an adjacent oncoming lane, and the oncoming lane intersects with the driving route. These are situations where the host vehicle 1 needs to enter another lane, and needs to stop temporarily before entering the other lane so as not to interfere with other vehicles traveling in the other lane. The detection unit 105 first queries the map database 5 to obtain map information on the travel route within a predetermined distance ahead of the host vehicle 1 in the travel direction. The predetermined distance may be set to a distance of several hundred meters, and may be variable so that it becomes longer as the speed of the host vehicle 1 increases.

Next, the detection unit 105 detects an intersection scene that exists on the driving route within a predetermined distance from the vehicle based on the map information acquired from the map database 5. For example, the detection unit 105 acquires information on other lanes that intersect with the driving route as map information, and detects a scene where the driving route intersects with the other lanes as an intersection scene. The detection unit 105 may also acquire information on other lanes that intersect with the driving route based on information on the driving environment around the vehicle 1 recognized by the external information recognition unit 14, and detect a scene where the driving route intersects with the other lanes as an intersection scene. The detection unit 105 may also detect an intersection scene by referring to a scene database that stores scenes that correspond to intersection scenes, such as a scene where the driving route crosses another lane or a scene where the driving route merges with a priority road, and detects an intersection scene based on whether or not the scene acquired from the map information corresponds to a scene stored in the scene database. In this embodiment, while the vehicle 1 is traveling toward the destination, the detection unit 105 repeatedly detects the intersection scene. Then, when an intersection scene is detected, the stop position setting control described later is executed. On the other hand, if no intersection is detected, driving control is performed according to automatic driving control or driving assistance control.

The position setting unit 106 sets a target stop position on the travel path in the intersection scene where the host vehicle stops before passing the lane boundary between the host lane and another lane. Specifically, the position setting unit 106 sets the target stop position so that the host vehicle 1 can be stopped at a position as close as possible to the intersection point between the travel path and the lane boundary without going beyond the lane boundary. That is, the position setting unit 106 sets the target stop position at a position on the travel path that is not included in an area where another vehicle traveling on another lane may pass and where the direction of the travel path at that position is at an angle to the lane boundary. The position where the direction of the travel path at that position is at an angle to the lane boundary is a position where the direction of the travel path and the lane boundary are not parallel. Specifically, the target stop position is set at a position where the tangent direction of the travel path at a position on the travel path intersects with the direction of the lane boundary at a position on the lane boundary that is the shortest distance from the position on the travel path. First, the position setting unit 106 extracts an intersection point where the driving path intersects with the lane boundary line on the driving path in the intersection scene by the intersection point extraction unit 107. Specifically, the position setting unit 106 acquires the coordinates on the map data of the position where the driving path intersects with the lane boundary line in the intersection scene as the intersection point. In addition, when there are multiple intersection scenes that exist within a predetermined distance from the host vehicle 1, the position setting unit 106 extracts the position where the driving path intersects with the lane boundary line in the intersection scene closest to the host vehicle as the intersection point.

Next, the position setting unit 106 sets the target stop position using a normal line of a predetermined length. Specifically, the position setting unit 106 sets a normal line that perpendicularly intersects with the driving route at the starting point on the driving route, using the normal line setting unit 108, with the starting point as a reference. The predetermined length of the normal line is set to be equal to or greater than the vehicle width of the vehicle 1. However, the predetermined length of the normal line is shorter than the lane width of the lane in which the vehicle 1 is traveling. The normal line is a line that becomes the position of the front end of the vehicle 1 when the vehicle 1 stops. In other words, the vehicle 1 stops so that the front end of the vehicle 1 is along the normal line. As a result, in this embodiment, the position setting unit 106 sets the target stop position at which the vehicle 1 stops so as not to go beyond the lane boundary line. The position setting unit 106 first sets the intersection extracted by the intersection extraction unit 107 as the starting point, and sets a normal line that perpendicularly intersects with the driving route at the starting point. Next, the position setting unit 106 determines whether the normal line intersects with a lane boundary line by the position determination unit 109. In this embodiment, an area including a position on the driving route that is the starting point of the normal line that intersects with the lane boundary line is identified as an area through which another vehicle traveling in another lane may pass. If it is determined that the normal line intersects with the lane boundary line, the position setting unit 106 resets the starting point to a position that is moved a predetermined distance D (e.g., 1 m) backward along the driving route from the intersection point. Here, the predetermined distance D may be set as small as possible, taking into account the accuracy of GPS2 and map data and the load of calculation processing.

Next, the position setting unit 106 sets a normal line that intersects perpendicularly with the driving route at the starting point, based on the reset starting point. Then, the position setting unit 106 determines whether the reset normal line intersects with the lane boundary line. If it is determined that the normal line does not intersect with the lane boundary line, the position setting unit 106 sets the target stop position to the position of the normal line at the time when it is determined that the normal line does not intersect with the lane boundary line. That is, in this embodiment, the position setting unit 106 repeatedly executes the above-mentioned setting of the starting point and the normal line until it is determined that the normal line does not intersect with the lane boundary line, and when a normal line that does not intersect with the lane boundary line is set, the target stop position is set to the position of the normal line at that time. As a result, the position setting unit 106 identifies the normal line closest to the intersection point among the normal lines excluding the normal lines that intersect with the lane boundary line, identifies the position of the identified normal line, and sets the target stop position to the identified position. That is, the position setting unit 106 can set the target stop position at a position outside the area where other vehicles traveling in other lanes may pass by setting the target stop position among normal lines excluding normal lines that intersect with the lane boundary line. In this embodiment, the predetermined length of the normal line is shorter than the lane width of the own lane. Therefore, by searching for the position of the normal line that does not intersect with the lane boundary line along the travel path, the target stop position is set at a position closer to the intersection point than a position where the direction of the travel path is parallel to the boundary line, that is, a position where the direction of the travel path is at an angle to the lane boundary line.

Figure 3 is a diagram showing an example of setting a target stop position in an intersection scene. Figure 3 shows a scene in which the vehicle 1 crosses the oncoming lane adjacent to the vehicle lane along the travel route R and enters a road on private land. The position setting unit 106 first sets the intersection point of the travel route R and the boundary line between the vehicle lane and the oncoming lane as a starting point P1. Next, the position setting unit 106 sets a normal line L1 that intersects perpendicularly with the travel route R at the intersection point that is the starting point P1, and determines whether the normal line L1 intersects with the boundary line. Since the normal line L1 intersects with the boundary line, the position setting unit 106 sets a position that is a predetermined distance D behind the starting point P1 along the travel route as the starting point P2. Then, the position setting unit 106 sets a normal line L2 that intersects perpendicularly with the travel route R at the starting point P2, and determines whether the normal line L2 intersects with the boundary line. Because the normal line L2 also intersects with the boundary line, the position setting unit 106 further sets a position a predetermined distance D behind the starting point P2 along the travel route as the starting point P3. The position setting unit 106 then sets a normal line L3 that intersects perpendicularly with the travel route R at the starting point P3, and determines whether the normal line L3 intersects with the boundary line. Because the normal line L3 does not intersect with the boundary line, the position setting unit 106 sets the target stop position of the host vehicle 1 to the starting point P3, which is a position on the travel route at the normal line L3.

The position setting unit 106 may also adjust the target stop position in the forward and backward directions along the travel route. Specifically, the position setting unit 106 sets the target stop position to a position on the travel route outside an area where other vehicles traveling on other lanes may pass. The area where other vehicles traveling on other lanes may pass includes not only areas on other lanes but also areas on the vehicle's own lane. For example, when a parked vehicle exists on a narrow other lane, other vehicles traveling on the oncoming lane may travel so that a part of the vehicle body crosses the lane boundary line to avoid the parked vehicle. Even in such a case, the vehicle 1 stopped at the target stop position does not interfere with the travel of other vehicles, so that the position setting unit 106 sets the target stop position outside an area where other vehicles may cross the lane boundary line. Specifically, the position setting unit 106 corrects the position of the normal line that does not intersect with the lane boundary line by changing the predetermined length of the normal line. As a result, the position setting unit 106 adjusts the target stop position in the forward and backward directions along the travel route by changing the predetermined length of the normal line. For example, the longer the predetermined length of the normal line, the farther the position of the normal line that does not intersect with the lane boundary line is set from the intersection point between the driving path and the lane boundary line.

In this embodiment, the predetermined length of the normal line is set according to the driving environment of the intersection scene. The driving environment includes the number and width of other lanes, the number and width of the lane of the own lane, the road structure including the guide strip of the intersection scene, and the presence or absence of parked vehicles on the other lanes and the own lane. For example, when the number of lanes of the other lane is one lane and the lane width is shorter than the width of two vehicles, when a parked vehicle exists on the other lane, the other vehicle traveling on the other lane may run with a part of the vehicle body protruding into the own lane in which the own vehicle 1 is traveling in order to avoid the parked vehicle. On the other hand, for example, when the number of lanes of the other lane is two or more lanes, even when a parked vehicle exists on the other lane, the other vehicle may not run with a part of the vehicle body protruding into the own lane by running on the adjacent lane. Also, for example, if a guidance strip exists between the own lane and another lane, there is a possibility that another vehicle will pass over the guidance strip. Therefore, when a guidance strip exists, the predetermined length of the normal line is set so as not to set the target stop position in an area where another vehicle may pass. Also, depending on the driving environment of the own lane, there is a possibility that the own vehicle will stop at the target stop position and interfere with the driving of a following vehicle traveling on the own lane. Therefore, the target stop position is set as close as possible to the intersection of the driving path and the lane boundary line so as not to interfere with the driving of the following vehicle. The predetermined length of the normal line may be set according to the vehicle speed of the surrounding other vehicles as the driving environment. For example, when the vehicle speed of the other vehicle traveling on the other lane is equal to or higher than a predetermined threshold, the position setting unit 106 sets the predetermined length of the normal line to be longer than when the vehicle speed of the other vehicle is less than the predetermined threshold.

ここで、Ｌが法線の長さであり、Ａは、自車両１の車幅である。また、Ｋｚ、Ｋｅ、及びＫｃは重みである。ただし、Ｋｚ：Ｋｅ＝２：１、Ｋｅ：Ｋｃ＝１：１である。Ｘ（Ｘｚ、Ｘｅ、Ｘｃ）は、各条件に応じて設定される値であり、０か１の値が設定される。Ｘｚは、交差場面における導流帯の有無に応じて設定される値であり、導流帯がある場合には、１が設定され、導流帯がない場合には、０が設定される。また、Ｘｅは、自車線の走行環境に応じて設定される値であり、自車線の走行環境に基づいて、０か１の値が設定される。また、Ｘｃは、他車線の走行環境に応じて設定される値であり、他車線の走行環境に基づいて、０か１の値が設定される。Ｘｅの値は、自車線の走行環境ごとに予め設定されている値である。例えば、表１に示されるように、Ｘｅの値は、自車線の走行環境に応じた値が設定されている。また、本実施形態では、位置設定部１０６は、上述の走行環境に係る各条件全てを用いて、法線の長さを設定することに限らず、走行環境に係る条件のうちいずれかひとつあるいは複数の組み合わせを用いて、法線の長さを設定することとしてもよい。

表１において、Ｘｅの値は、自車線における車線数と車線幅と駐車車両の有無に応じて設定されている。車線幅は、所定の閾値以上であれば、「大」として特定され、所定の閾値未満であれば、「小」として特定される。例えば、所定の閾値は、一般的な車両２台分の車幅と同じ幅である。表１では、例えば、自車線の車線数が１車線で、自車線の車線幅が「大」で、自車線に駐車車両が存在する場合には、Ｘｅの値は、０であることを示している。表１の車線幅が「大／小」となっているのは、車線幅の「大」「小」がいずれの場合でも含まれるということを意味し、駐車車両の有無が「有／無」となっているのは、駐車車両が存在する場合も、存在しない場合も含まれるということを意味する。 In this embodiment, the predetermined length of the normal line is set, for example, as shown in the following formula (1).

Here, L is the length of the normal line, and A is the vehicle width of the vehicle 1. Kz, Ke, and Kc are weights. However, Kz:Ke=2:1, and Ke:Kc=1:1. X (Xz, Xe, Xc) is a value set according to each condition, and a value of 0 or 1 is set. Xz is a value set according to the presence or absence of a guidance strip in the intersection scene, and if there is a guidance strip, 1 is set, and if there is no guidance strip, 0 is set. Xe is a value set according to the running environment of the own lane, and a value of 0 or 1 is set based on the running environment of the own lane. Xc is a value set according to the running environment of the other lane, and a value of 0 or 1 is set based on the running environment of the other lane. The value of Xe is a value that is preset for each running environment of the own lane. For example, as shown in Table 1, the value of Xe is set to a value according to the running environment of the own lane. Furthermore, in this embodiment, the position setting unit 106 is not limited to setting the length of the normal line using all of the conditions related to the driving environment described above, but may set the length of the normal line using any one or a combination of multiple conditions related to the driving environment.

In Table 1, the value of Xe is set according to the number of lanes in the own lane, the lane width, and the presence or absence of parked vehicles. If the lane width is equal to or greater than a predetermined threshold, it is specified as "large", and if it is less than the predetermined threshold, it is specified as "small". For example, the predetermined threshold is the same width as the width of two general vehicles. In Table 1, for example, when the number of lanes in the own lane is one, the lane width of the own lane is "large", and a parked vehicle is present in the own lane, the value of Xe is 0. The lane width in Table 1 is "large/small" meaning that both the lane widths "large" and "small" are included, and the presence or absence of parked vehicles is "present/absent" meaning that both the presence and absence of parked vehicles are included.

表２において、Ｘｃの値は、他車線の車線数と車線幅と駐車車両の有無に応じて設定されている。車線幅は、所定の閾値以上であれば、「大」として特定され、所定の閾値未満であれば、「小」として特定される。例えば、所定の閾値は、一般的な車両２台分の車幅と同じ幅である。表２では、例えば、他車線の車線数が１車線で、自車線の車線幅が「小」で、自車線に駐車車両が存在する場合には、Ｘｅの値は、１であることを示している。また、表２の車線幅が「大／小」となっているのは、車線幅の「大」「小」がいずれの場合でも含まれるということを意味し、駐車車両の有無が「有／無」となっているのは、駐車車両が存在する場合も、存在しない場合も含まれるということを意味する。 Furthermore, Xc is a value that is set according to the driving environment of the other lanes, and is set to a value of 0 or 1 based on the driving environment of the other lanes. The value of Xc is a value that is set in advance for each driving environment of the other lanes. For example, as shown in Table 2, the value of Xc is set to a value that corresponds to the driving environment of the other lanes.

In Table 2, the value of Xc is set according to the number of other lanes, the lane width, and the presence or absence of parked vehicles. If the lane width is equal to or greater than a predetermined threshold, it is specified as "large", and if it is less than the predetermined threshold, it is specified as "small". For example, the predetermined threshold is the same width as the width of two general vehicles. In Table 2, for example, when the number of other lanes is one, the lane width of the own lane is "small", and a parked vehicle is present in the own lane, the value of Xe is 1. In addition, the lane width in Table 2 is "large/small" meaning that both the lane widths "large" and "small" are included, and the presence or absence of parked vehicles is "present/absent" meaning that both the presence and absence of parked vehicles are included.

In this embodiment, the position setting unit 106 acquires information on the driving environment at the intersection, such as the number of lanes of the vehicle and other lanes at the intersection, the vehicle width, the presence or absence of parked vehicles, and the presence or absence of a guidance strip, from the external information recognition unit 14 and/or the map database 5, and calculates the value of X (Xz, Xe, Xc) corresponding to the driving environment by referring to Tables 1 and 2. Next, the position setting unit 106 calculates a predetermined length L of the normal line based on the above formula (1), and sets a normal line of the calculated predetermined length L with a position on the driving route as a starting point. Then, the position setting unit 106 identifies a position of the normal line that does not intersect with a lane boundary line, and sets a target stop position at the position of the identified normal line.

Figure 4 is a diagram showing an example of a case where a guidance strip exists in an intersection scene. In Figure 4, a guidance strip is installed between the own lane and another lane adjacent to the own lane. When a guidance strip exists, other vehicles traveling in other lanes may pass over the guidance strip, so the position setting unit 106 sets the target stop position outside the area where other vehicles may pass. When a guidance strip exists, in an intersection scene, the position setting unit 106 extracts, as a starting point P1, an intersection point where the boundary line on the other lane side intersects with the traveling route, among the boundary lines on the own lane side and the boundary lines on the other lane side that form the guidance strip. Then, the position setting unit 106 sets, as the starting point P1, a normal line L1 that perpendicularly intersects with the traveling route at the starting point P1, with the extracted intersection point as the starting point P1. At this time, the predetermined length of the normal line is set longer than the predetermined length of the normal line in the case where the guidance strip does not exist. As a result, the position of the normal line that does not intersect with the lane boundary line is set further backward along the traveling route than the position of the normal line in the case where the guidance strip does not exist. As shown in FIG. 4, when a guidance band is present, a normal that does not intersect with the lane boundary line is set at the position of normal L2.

Figure 5 is a diagram showing an example of an intersection scene in which the width of the lane is narrow and a parked vehicle exists on the other lane. When a parked vehicle exists on the other lane, the other vehicle may cross the boundary line to avoid the parked vehicle, so the position setting unit 106 needs to set the target stop position of the vehicle 1 outside the area where the other vehicle may pass. At this time, the predetermined length of the normal line is set to be longer than the length of the normal line when there is no parked vehicle. As a result, the position of the normal line that does not intersect with the boundary line is set further back along the travel path than the position of the normal line when there is no parked vehicle. In Figure 5, the predetermined length of the normal line L2 when there is a parked vehicle is set to be longer than the normal line L1 when there is no parked vehicle, and the position of the normal line L2 is also set further back along the travel path than the position of the normal line L1.

FIG. 6 is a diagram showing an example of setting a target stop position when the vehicle is traveling on the own lane, which is a non-priority road that merges into another lane, which is a priority road. The position setting unit 106 first sets the intersection of the travel route R and the boundary line between the own lane and the oncoming lane as the starting point P1. Next, the position setting unit 106 sets a normal line L1 that intersects perpendicularly with the travel route R at the intersection point that is the starting point P1, and determines whether the normal line intersects with the boundary line. Since it is determined that the normal line L1 intersects with the boundary line, the position setting unit 106 sets a position that is a predetermined distance D behind the starting point P1 along the travel route as the starting point P2. Then, the position setting unit 106 sets a normal line L2 that intersects perpendicularly with the travel route R at the starting point P2, and determines whether the normal line L2 intersects with the boundary line. Because it is determined that the normal line L2 does not intersect with the boundary line, the position setting unit 106 sets the starting point P2, which is the position on the driving route on the normal line L2, as the target stopping position of the vehicle.

Next, the control procedure of the driving support method according to this embodiment will be described with reference to FIG. 7. FIG. 7 is a diagram showing the control flow of the driving support method according to this embodiment. In this embodiment, when the host vehicle 1 starts traveling, the processor 110 starts the control flow from step S101. First, in step S101, the processor 110 generates a driving route for the host vehicle. In step S102, the processor 110 acquires map information and/or external recognition information within a range within a predetermined distance in the traveling direction from the host vehicle on the driving route. For example, the processor 110 acquires a road structure including a lane boundary line between the host lane and another lane. In step S103, the processor 110 detects an intersection scene where the driving route and the lane boundary line intersect. The intersection scene includes, for example, a scene where the host vehicle 1 crosses the lane boundary line between the host lane and another lane and crosses the other lane. In step S104, the processor 110 acquires the driving environment of the intersection scene. The driving environment includes, for example, the number and width of lanes in the current and other lanes, the presence or absence of parked vehicles in the current and other lanes, and the presence or absence of guidance strips.

In step S105, the processor 110 sets the predetermined length of the normal line to the vehicle width of the vehicle 1 or a length equal to or greater than the vehicle width. Specifically, the processor 110 sets the length of the normal line based on the information on the driving environment acquired in step S104. In step S106, the processor 110 sets the intersection point between the driving path and the lane boundary line as the starting point. Specifically, the processor 110 extracts the coordinates of the position where the driving path and the lane boundary line intersect as the intersection point, and sets the extracted intersection point as the starting point. In step S107, the processor 110 sets the normal line at the starting point. Specifically, the processor 110 sets the normal line so that the normal line of the set predetermined length intersects the driving path perpendicularly at the starting point. In step S108, the processor 110 determines whether the normal line intersects the lane boundary line. If the normal line intersects the lane boundary line, the process proceeds to step S109. If the normal line does not intersect the lane boundary line, the process proceeds to step S110.

In step S109, the processor 110 resets the starting point to a position a predetermined distance D behind along the travel route. After resetting, the processor 110 returns to step S107 and repeats the flow below. In step S110, the processor 110 sets the target stop position of the host vehicle 1 to the position of the normal line determined not to intersect with the lane boundary line in step S108. In step S111, the processor 110 executes stop control to stop the host vehicle 1 at the target stop position. Specifically, the processor 110 generates a vehicle speed profile so that the target vehicle speed of the host vehicle 1 is 0 m/s at the target stop position, and outputs the target vehicle speed to the brake controller 8 so that the vehicle speed is controlled according to the vehicle speed profile. Then, the brake controller 8 controls the host vehicle 1 to stop at the target stop position using the target vehicle speed. In step S112, the processor 110 stops the vehicle 1 at the target stop position, acquires the position and vehicle speed of the other vehicle acquired by the external information recognition unit 14, and determines whether it is possible to cross the other lane. If it is determined that it is possible to cross the other lane, the processor 110 executes driving control to cross the other lane.

As described above, this embodiment is a driving assistance method that generates a driving route for the host vehicle, detects an intersection scene where the driving route intersects with another lane that is traveling in a different direction from the host vehicle's lane, and sets a target stop position on the driving route at the intersection scene where the host vehicle will stop before crossing the boundary line between the host vehicle's lane and the other lane, and sets the target stop position for the host vehicle at a position on the driving route that is not included in an area where another vehicle traveling in the other lane may pass and where the direction of the driving route at the position is at an angle to the boundary line. This reduces the time it takes for the host vehicle to cross the oncoming lane from the stopping position.

In addition, in this embodiment, an intersection point between the driving path and the boundary line is extracted on the driving path in the intersection scene, a normal line of a predetermined length that intersects perpendicularly with the driving path at a position on the driving path is set, the normal line closest to the intersection point is identified from among the normal lines excluding the normal lines that intersect with the boundary line, the position on the driving path of the identified normal line is identified, and a target stop position for the host vehicle is set at the identified position. This makes it possible to set a target stop position at a position on the driving path excluding areas where other vehicles traveling in other lanes may pass.

In addition, in this embodiment, the predetermined length of the normal line is set to the vehicle width of the host vehicle or a length equal to or greater than the vehicle width. This allows the host vehicle to stop without going beyond the lane boundary line.

In addition, in this embodiment, at least one of the following driving environment information is acquired as driving environment information related to the driving environment at the intersection: the speed of other vehicles, the number of other lanes, and the presence or absence of parked vehicles on other lanes. Based on the acquired driving environment information, a predetermined length of the normal line is set. This allows the host vehicle to stop at a target stop position that is appropriate for the driving environment of the host vehicle's lane and other lanes.

In addition, in this embodiment, if a guidance strip formed by the boundary line of the vehicle's own lane and the boundary line of the other lane is present on the driving route at an intersection, the boundary line of the other lane is set as the boundary line. This makes it possible to set the target stop position based on the boundary line of the other lane even if a guidance strip is present at an intersection.

In addition, in this embodiment, a scene where the driving route intersects with another lane, which is an oncoming lane of the own vehicle, or a scene where a driving route passing through the own vehicle lane, which is a non-priority road, merges with another lane, which is a priority road, is detected as an intersection scene. This makes it possible to set an appropriate target stop position in a scene where there is a possibility of interference with another vehicle traveling in another lane.

The above-described embodiments are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

Reference Signs List 1... Vehicle 100... Driving support device 110... Processor 101... Route generation unit 102... Driving route generation unit 103... Target speed generation unit 104... Steering target generation unit 105... Detection unit 106... Position setting unit 107... Intersection extraction unit 108... Normal line setting unit 109... Position determination unit

Claims (5)

A processor of the driving assistance device
Generate a driving route for the vehicle;
Detecting an intersection scene where the travel route intersects with another lane having a different traveling direction from the lane in which the host vehicle is traveling;
A driving assistance method for setting a target stop position at which the host vehicle stops before passing a boundary line between the host lane and the other lane on the driving route in the intersection scene,
Extracting an intersection between the travel route and the boundary line on the travel route in the intersection scene;
setting a normal line having a predetermined length perpendicular to the travel route at a position on the travel route;
Identifying the normal closest to the intersection point among the normals excluding the normals that intersect the boundary line;
Identifying a position on the travel path of the identified normal line;
setting the target stop position of the host vehicle at the specified position;
The specified position is a position on the travel route that is not included in an area where another vehicle traveling on the other lane may pass, and the direction of the travel route at the position is at an angle with respect to the boundary line,
A driving assistance method , wherein the predetermined length of the normal line is set based on driving environment information relating to the driving environment of the intersection scene . The processor,
The driving assistance method according to claim 1 , wherein at least one of information regarding the driving environment at the intersection scene is obtained from among the vehicle speed of the other vehicle, the number of the other lanes, and information regarding the presence or absence of parked vehicles on the other lanes. The processor,
When a guidance strip formed by the boundary line on the vehicle's own lane side and the boundary line on the other lane side exists on the driving route at the intersection scene,
The driving support method according to claim 1 or 2 , wherein the boundary line on the other lane side is set as the boundary line. The processor,
The driving support method according to any one of claims 1 to 3, wherein a scene where the other lane, which is an oncoming lane of the own vehicle lane, intersects with the driving route, or a scene where the driving route passing through the own vehicle lane, which is a non-priority road, merges into the other lane, which is a priority road, is detected as the intersection scene. A route generation unit that generates a driving route for the host vehicle;
A detection unit that detects an intersection scene where the travel route intersects with another lane having a different traveling direction from the lane in which the host vehicle is traveling;
a position setting unit that sets a target stop position at which the host vehicle will stop before passing a boundary line between the host lane and the other lane on the driving route in the intersection scene,
The position setting unit is
Extracting an intersection between the travel route and the boundary line on the travel route in the intersection scene;
setting a normal line having a predetermined length perpendicular to the travel route at a position on the travel route;
Identifying the normal closest to the intersection point among the normals excluding the normals that intersect the boundary line;
Identifying a position on the travel path of the identified normal line;
setting the target stop position of the host vehicle at the specified position;
The specified position is a position on the travel route that is not included in an area where another vehicle traveling on the other lane may pass, and the direction of the travel route at the position is at an angle with respect to the boundary line,
A driving assistance device in which the predetermined length of the normal line is set based on driving environment information related to the driving environment of the intersection scene .

Images