WO2025009143A1 - Driving assistance device and driving assistance method - Google Patents

Abstract

A driving assistance device (10) comprises: a preceding vehicle recognition unit (11) that recognizes a preceding vehicle (101) which is followed by a host vehicle (100); a travel state recognition unit (12) that recognizes the travel states of the preceding vehicle (101) and the host vehicle (100); and a following-travel control unit (13) that executes following-travel control to cause the host vehicle (100) to travel so as to follow the preceding vehicle (101). When executing the following-travel control, the following-travel control unit (13) determines, on the basis of the travel states of the preceding vehicle (101) and the host vehicle (100), whether to set the lane in which the host vehicle (100) travels to a lane different from that of the preceding vehicle (101).

Description

Driving assistance device and driving assistance method

This disclosure relates to a driving assistance device that performs follow-up driving control to make a vehicle follow a preceding vehicle.

Patent Document 1 discloses a driving support device that, when it is predicted that only some of the vehicles in a platoon will need to stop at the next traffic light, accelerates the platoon or closes the gaps between the vehicles in the platoon to allow all the vehicles in the platoon to pass before the traffic light issues a stop instruction, thereby preventing the platoon from becoming disrupted.

JP 2019-105878 A

The technology in Patent Document 1 is based on the premise that the leading vehicle in the platoon and the following vehicles following it travel in the same lane. However, depending on the driving conditions of the vehicle group, it may be more advantageous for the leading vehicle and the following vehicles to travel in different lanes in order to prevent the following relationship between the leading vehicle and the following vehicle from being interrupted.

The present disclosure has been made to solve the above problems, and aims to provide a driving assistance device that, when performing follow-up cruise control, determines whether or not to make the host vehicle travel in a lane different from the lane in which the preceding vehicle travels, depending on the driving conditions.

The driving assistance device according to the present disclosure includes a preceding vehicle recognition unit that recognizes a preceding vehicle that the host vehicle is to follow, a driving condition recognition unit that recognizes the driving conditions of the preceding vehicle and the host vehicle, and a following driving control unit that performs following driving control to cause the host vehicle to follow the preceding vehicle, and when performing the following driving control, the following driving control unit determines whether or not to make the host vehicle travel in a lane different from that of the preceding vehicle based on the driving conditions of the preceding vehicle and the host vehicle.

The driving assistance device according to the present disclosure determines whether or not to drive the vehicle in a lane different from that of the preceding vehicle depending on the driving conditions of the preceding vehicle and the vehicle itself. This helps to prevent the following relationship between the preceding vehicle and the vehicle itself from being interrupted.

The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and accompanying drawings.

1 is a block diagram showing a configuration of a driving assistance device according to a first embodiment; 3 is a diagram for explaining the operation of the driving assistance device according to the first embodiment; FIG. 3 is a diagram for explaining the operation of the driving assistance device according to the first embodiment; FIG. 4 is a flowchart showing an operation of the driving assistance device according to the first embodiment. 4 is a flowchart showing follow-up cruise control in the first embodiment. FIG. 11 is a block diagram showing a configuration of a driving assistance device according to a second embodiment. FIG. 11 is a diagram for explaining the operation of the driving assistance device according to the second embodiment. FIG. 11 is a diagram for explaining the operation of the driving assistance device according to the second embodiment. FIG. 11 is a diagram for explaining the operation of the driving assistance device according to the second embodiment. FIG. 11 is a diagram for explaining the operation of the driving assistance device according to the second embodiment. 11 is a flowchart showing follow-up cruise control in the second embodiment. FIG. 11 is a block diagram showing a configuration of a driving assistance device according to a third embodiment. FIG. 11 is a diagram for explaining the operation of the driving assistance device according to the third embodiment. FIG. 11 is a diagram for explaining the operation of the driving assistance device according to the third embodiment. 13 is a flowchart showing follow-up cruise control in the third embodiment. FIG. 2 is a diagram illustrating an example of a hardware configuration of a driving support device. FIG. 2 is a diagram illustrating an example of a hardware configuration of a driving support device.

<First embodiment>
Fig. 1 is a block diagram showing a configuration of a driving assistance device 10 according to embodiment 1. Note that Fig. 1 shows only the minimum components necessary for explaining the present embodiment, and the driving assistance device 10 as an actual product may include various functional blocks not shown in Fig. 1.

In this embodiment, the driving assistance device 10 is mounted on the vehicle 100, and hereinafter, the vehicle 100 mounted with the driving assistance device 10 is referred to as the "own vehicle". However, the driving assistance device 10 does not need to be permanently installed on the own vehicle 100, and may be configured to be removable from the own vehicle 100, for example. In that case, the driving assistance device 10 may be realized on a mobile terminal such as a mobile phone, smartphone, or PND (Portable Navigation Device).

As shown in FIG. 1, the driving assistance device 10 is connected to the driving control device 20, the surroundings detection device 21, the locator 22, and the road-to-vehicle communication device 23 of the vehicle 100.

The driving control device 20 is an ECU (Electronic Control Unit) that controls the acceleration, deceleration, steering, etc. of the host vehicle 100. By controlling the driving control device 20, the driving assistance device 10 can implement following driving control that causes the host vehicle 100 to follow a leading vehicle (not shown in FIG. 1).

The periphery detection device 21 is composed of, for example, LiDAR (Light Detection And Ranging), an in-vehicle camera, an image processing device, etc., and detects the surrounding conditions of the host vehicle 100. The driving assistance device 10 can acquire information on the surrounding conditions of the host vehicle 100 from the periphery detection device 21, such as the positions, movement direction, and movement speed of other vehicles and obstacles present around the host vehicle 100. Hereinafter, the information on the surrounding conditions of the host vehicle 100 detected by the periphery detection device 21 is referred to as "periphery information".

The locator 22 is a high-precision locator (HDL) equipped with high-precision map data (HD map data) having road shape information on a lane-by-lane basis and a high-precision positioning unit that uses GNSS (Global Navigation Satellite System), and collates the measured position of the vehicle 100 with the high-precision map data to identify the road and lane on which the vehicle 100 is traveling. The driving assistance device 10 can obtain information on the position of the vehicle 100 and the road and lane on which the vehicle is traveling from the locator 22.

The road-to-vehicle communication device 23 acquires various types of traffic-related information through wireless communication with infrastructure equipment such as roadside devices. In this embodiment, the road-to-vehicle communication device 23 has a function of communicating with traffic lights, acquires traffic light information including information on the color currently displayed by the traffic light and information on the timing of color switching displayed by the traffic light, and provides this information to the driving assistance device 10. The road-to-vehicle communication device 23 may acquire traffic light information from a server that distributes traffic light information, rather than acquiring the traffic light information directly from the traffic light.

The driving assistance device 10 includes a preceding vehicle recognition unit 11, a driving situation recognition unit 12, and a following driving control unit 13.

The leading vehicle recognition unit 11 recognizes a leading vehicle that the host vehicle 100 is to follow based on the surrounding information acquired from the surrounding detection device 21. The method by which the leading vehicle recognition unit 11 selects a vehicle that the host vehicle 100 is to follow can be the same as that used in general following driving control, so a description thereof will be omitted here.

The driving condition recognition unit 12 recognizes the driving conditions of the preceding vehicle and the vehicle itself 100 based on traffic light information obtained from the road-to-vehicle communication device 23, information on the position of the vehicle itself 100 obtained from the locator 22, the lane in which the vehicle is traveling, etc., and information on the preceding vehicle recognized by the preceding vehicle recognition unit 11.

The following driving control unit 13 performs following driving control, which controls the driving control device 20 so that the host vehicle 100 drives following the preceding vehicle recognized by the preceding vehicle recognition unit 11. In addition, when performing following driving control, the following driving control unit 13 determines whether the host vehicle 100 will drive in the same lane as the preceding vehicle or in a different lane, based on the driving conditions of the preceding vehicle and the host vehicle 100 recognized by the driving condition recognition unit 12.

In the driving assistance device 10 according to the first embodiment, the driving situation recognition unit 12 recognizes the positional relationship between the preceding vehicle and the vehicle itself 100, and a specific road facility. Here, an example is shown in which the specific road facility is a traffic light. In this case, the driving situation recognition unit 12 recognizes not only the positional relationship between the preceding vehicle and the vehicle itself 100, and a traffic light, but also traffic light information including information on the timing at which the traffic light display changes.

The following driving control unit 13 also determines whether or not the host vehicle 100 should travel in a lane different from that of the preceding vehicle when the host vehicle 100 follows the preceding vehicle and passes through a specific road facility, i.e., a traffic light.

For example, as shown in FIG. 2, when the vehicle 100 is traveling following the preceding vehicle 101 in the same lane as the preceding vehicle 101 and the vehicle 100 approaches a traffic light, the following travel control unit 13 calculates the timing when the preceding vehicle 101 and the vehicle 100 will each reach the traffic light based on the positional relationship between the preceding vehicle and the vehicle 100 and the traffic light, and the travel speeds of the preceding vehicle and the vehicle 100, and also calculates the timing when the traffic light will switch to a stop signal (i.e., a red light) based on the traffic light information.

As a result, if it is determined that the timing at which the traffic light will switch to a stop command will occur before the preceding vehicle 101 and the vehicle 100 reach the traffic light, the following driving control unit 13 will maintain the vehicle 100 in the same lane as the preceding vehicle 101, and make the vehicle 100 follow the preceding vehicle 101, stopping the vehicle 100 in front of the traffic light.

In addition, if it is determined that the timing at which the traffic light switches to a stop instruction will be after the preceding vehicle 101 and the vehicle 100 pass through the traffic light, the following driving control unit 13 maintains the lane in which the vehicle 100 is traveling in the same lane as the preceding vehicle 101, and causes the vehicle 100 to follow the preceding vehicle 101 and pass through the traffic light.

If it is determined that the timing at which the traffic light will switch to a stop command will be between the timing at which the preceding vehicle 101 passes the traffic light and the timing at which the host vehicle 100 passes the traffic light, the following driving control unit 13 determines that the host vehicle 100 will travel in a lane different from that of the preceding vehicle 101. Then, as shown in FIG. 3, the host vehicle 100 changes lanes and passes the traffic light side-by-side with the preceding vehicle 101.

However, the driving situation recognition unit 12 recognizes the positional relationship between the preceding vehicle 101, the vehicle 100, and surrounding vehicles (including the preceding vehicle 101), and if the following driving control unit 13 determines that the vehicle 100 cannot pass the traffic light side by side with the preceding vehicle 101 based on the positional relationship between the preceding vehicle 101, the vehicle 100, and surrounding vehicles, it cancels the following driving control with the preceding vehicle 101 as the following target in order to stop the vehicle 100 in front of the traffic light. In this case, only the preceding vehicle 101 will pass the traffic light, but the driving support device 10 may request the preceding vehicle 101 to wait beyond the traffic light using an inter-vehicle communication device (not shown) so that the following driving control with the preceding vehicle 101 as the following target can be resumed.

FIG. 4 is a flowchart showing the operation of the driving assistance device 10. The operation of the driving assistance device 10 will be explained below with reference to FIG. 4.

When the driver of the vehicle 100 instructs the driving assistance device 10 to perform follow-up cruise control, the flow in Figure 4 begins.

First, the preceding vehicle recognition unit 11 recognizes the preceding vehicle that the host vehicle 100 is to follow based on the surrounding information acquired from the surrounding detection device 21 (step S1).

Next, the driving condition recognition unit 12 recognizes the driving conditions of the preceding vehicle and the vehicle 100 based on the traffic light information acquired from the road-vehicle communication device 23, the position of the vehicle 100 acquired from the locator 22, the lane in which the vehicle is traveling, etc., and the information of the preceding vehicle recognized by the preceding vehicle recognition unit 11 (step S2).

Then, the following driving control unit 13 performs following driving control to control the driving control device 20 so that the host vehicle 100 follows the preceding vehicle recognized by the preceding vehicle recognition unit 11 (step S3). The details of step S3 will be described later.

If the following cruise control is not released in step S3 (NO in step S4), steps S1 to S3 are repeatedly executed. If the following cruise control is released in step S3 (YES in step S4), the flow in FIG. 4 ends.

FIG. 5 is a flowchart showing the following cruise control performed by the driving assistance device 10 according to the first embodiment, and the flow of FIG. 5 is executed in step S3 of FIG. 4.

When step S3 in FIG. 4 is started, the following driving control unit 13 first determines whether the host vehicle 100 has approached a traffic light (step S301). The determination of whether the host vehicle 100 has approached a traffic light is made, for example, based on whether the distance or the time required from the host vehicle 100 to the traffic light is equal to or less than a predetermined threshold.

If the host vehicle 100 is not approaching a traffic light (NO in step S301), the following driving control unit 13 maintains the host vehicle 100 in the same lane as the preceding vehicle, performs following driving control (step S306), and ends the flow in FIG. 5 (transitions to step S4 in FIG. 4).

If the host vehicle 100 is approaching a traffic light (YES in step S301), the following driving control unit 13 calculates the timing T1 at which the preceding vehicle will reach the traffic light based on the positional relationship between the host vehicle 100 and the traffic light and the traveling speed of the preceding vehicle (step S302). The following driving control unit 13 also calculates the timing T2 at which the host vehicle 100 will reach the traffic light based on the positional relationship between the host vehicle 100 and the traffic light and the traveling speed of the host vehicle 100 (step S303). Furthermore, the following driving control unit 13 calculates the timing Tc at which the traffic light will switch to a stop instruction (red light) based on the traffic light information (step S304).

Then, the following driving control unit 13 compares timings T1, T2, and Tc with each other, and determines whether timing Tc is between timings T1 and T2 (step S305). If timing Tc is not between timings T1 and T2 (NO in step S305), the following driving control unit 13 maintains the lane in which the host vehicle 100 is traveling in the same lane as the preceding vehicle, performs following driving control (step S306), and ends the flow of FIG. 5. In this case, the preceding vehicle and the host vehicle 100 will both pass through the traffic light in response to a proceed instruction (green light) from the traffic light, or will both stop in front of the traffic light in response to a stop instruction (red light) from the traffic light, so following driving control will not be interrupted due to an instruction from the traffic light.

If the timing Tc is between the timing T1 and the timing T2 (YES in step S305), the following driving control unit 13 further determines whether or not the vehicle 100 can be positioned side-by-side with the preceding vehicle based on the positional relationship between the preceding vehicle, the vehicle 100, and the surrounding vehicles (step S307).

If the situation allows the host vehicle 100 to run alongside the preceding vehicle (YES in step S307), the following drive control unit 13 determines that the host vehicle 100 will run in a lane different from the preceding vehicle's lane, performs following drive control to run the host vehicle 100 alongside the preceding vehicle (step S308), and ends the flow in FIG. 5. In this case, the host vehicle 100 can pass through the traffic light together with the preceding vehicle, so following drive control is not interrupted due to the traffic light's instructions.

However, if the vehicle 100 is not in a position to be side-by-side with the preceding vehicle (NO in step S307), the following drive control unit 13 cancels the following drive control that has the preceding vehicle as the following target in order to stop the vehicle 100 in front of the traffic light (step S309), and ends the flow in FIG. 5.

In this way, the driving assistance device according to the first embodiment determines whether or not to make the host vehicle 100 travel in a lane different from that of the preceding vehicle, depending on the driving conditions of the preceding vehicle and the host vehicle 100. This helps to prevent the following relationship between the preceding vehicle and the host vehicle 100 from being interrupted.

[Modification 1]
The specific road facility is not limited to a traffic light. Here, as a first modification, an example will be shown in which the specific road facility is a toll booth on an expressway or the like.

In the first variant, the road-to-vehicle communication device 23 acquires toll gate information including information on the location of the toll gate, the number of gates at the toll gate, and the degree of congestion around each gate. The information on the location of the toll gate and the number of gates at the toll gate may be acquired from high-precision map data of the locator 22. The degree of congestion around each gate may be determined from the positions of surrounding vehicles detected by the surrounding detection device 21 when the vehicle 100 arrives at the toll gate.

The driving condition recognition unit 12 recognizes the driving conditions of the preceding vehicle and the vehicle itself 100 by recognizing the relative positions of the preceding vehicle and the vehicle itself 100 relative to the toll gate, and toll gate information including the number of gates at the toll gate and the degree of congestion around each gate.

The following driving control unit 13 calculates, based on the toll gate information, a first time difference which is the difference in timing at which the preceding vehicle and the subject vehicle 100 pass through the toll gate when the gate through which the subject vehicle 100 passes is the same as that of the preceding vehicle. The following driving control unit 13 also calculates, based on the toll gate information, a second time difference which is the difference in timing at which the preceding vehicle and the subject vehicle 100 pass through the toll gate when the gate through which the subject vehicle 100 passes is a gate different from that of the preceding vehicle.

If the following driving control unit 13 determines that the first time difference is smaller than the second time difference, it determines that the lane in which the host vehicle 100 will travel is the same lane as the preceding vehicle, and causes the host vehicle 100 to pass through the same gate as the preceding vehicle.

However, if the following driving control unit 13 determines that the second time difference is smaller than the first time difference, it determines that the lane in which the host vehicle 100 will travel is a lane different from that of the preceding vehicle, and causes the host vehicle 100 to pass through a gate different from that of the preceding vehicle. In addition, after the preceding vehicle and the host vehicle 100 have passed through the gate, the following driving control unit 13 returns the lane in which the host vehicle 100 will travel to the same lane as the preceding vehicle, and continues the following driving control.

This modified example prevents the vehicle 100 from separating from the preceding vehicle when passing through the toll gate, thereby realizing smooth following control.

[Modification 2]
The means by which the driving situation recognition unit 12 acquires information about the lane on which the vehicle 100 is traveling is not limited to the locator 22. For example, the driving situation recognition unit 12 can analyze an image of the surroundings of the vehicle 100 captured by an on-board camera of the periphery detection device 21 to recognize the number of lanes on the road on which the vehicle 100 is traveling and the lane on which the vehicle 100 is traveling. In this case, the locator 22 may be omitted.

Also, the locator 22 may use standard precision map data (SD map data) including information on the road shape and number of lanes for each road, and the driving situation recognition unit 12 may compare information on the number of lanes on the road on which the vehicle 100 is traveling with the analysis results of an image of the surroundings of the vehicle 100 to recognize the lane on which the vehicle 100 is traveling. In this case, there is no need to use a high precision locator (HDL) as the locator 22, which can contribute to cost reduction.

<Embodiment 2>
Fig. 6 is a block diagram showing the configuration of a driving assistance device 10 according to embodiment 2. In the configuration of Fig. 6, the road-to-vehicle communication device 23 is replaced with an inter-vehicle communication device 24 in the configuration of Fig. 1 .

The vehicle-to-vehicle communication device 24 is a means by which the cruise control device 20 communicates with vehicles surrounding the vehicle 100. In this embodiment, the driving situation recognition unit 12 of the driving assistance device 10 recognizes the positional relationship between the preceding vehicle and the vehicle 100 and the surrounding vehicles, and can recognize the operation of the preceding vehicle, in particular the operation of the preceding vehicle to overtake another vehicle, through the vehicle-to-vehicle communication device 24.

The following driving control unit 13 determines whether or not to make the host vehicle 100 travel in a lane different from that of the preceding vehicle when the preceding vehicle overtakes another vehicle, based on the positional relationship between the preceding vehicle, the host vehicle 100, and the surrounding vehicles. More specifically, the following driving control unit 13 determines whether or not it is possible to make the host vehicle 100 travel in the same lane as the preceding vehicle when the preceding vehicle overtakes another vehicle, based on the positional relationship between the preceding vehicle, the host vehicle 100, and the surrounding vehicles. If this is possible, the following driving control unit 13 determines that the host vehicle 100 travels in the same lane as the preceding vehicle, and makes the host vehicle 100 follow the preceding vehicle to overtake the other vehicle. However, if this is not possible, the following driving control that has the preceding vehicle as the follow-up target is canceled.

When the preceding vehicle is not overtaking another vehicle, the lane in which the vehicle 100 travels may be the same as the preceding vehicle or a different lane.

For example, as shown in FIG. 7, when the vehicle 100 is following the preceding vehicle 101 in the same lane as the preceding vehicle 101 and the driving situation recognition unit 12 recognizes that the preceding vehicle 101 is about to overtake another vehicle 102 ahead, the following driving control unit 13 judges whether the vehicle 100 can travel in the same lane as the preceding vehicle 101 even if the preceding vehicle 101 changes lanes to overtake. In the case of FIG. 7, there are no surrounding vehicles in the adjacent lanes of the preceding vehicle 101 and the vehicle 100, and the vehicle 100 can change lanes by following the lane change of the preceding vehicle 101 as shown in FIG. 8. Therefore, the following driving control unit 13 determines that the lane in which the vehicle 100 will travel is the same lane as the preceding vehicle 101, and causes the vehicle 100 to follow the preceding vehicle 101 and overtake the other vehicle 102.

However, for example, as shown in FIG. 9, when another vehicle 103, which is a surrounding vehicle other than the other vehicle 102, is present in an adjacent lane of the preceding vehicle 101 and the vehicle itself 100, and the vehicle itself 100 cannot change lanes to follow the lane change of the preceding vehicle 101, the following travel control unit 13 cancels the following travel control with the preceding vehicle as the following target. Therefore, as shown in FIG. 10, even if the preceding vehicle 101 changes lanes to overtake, the vehicle itself 100 does not follow it and maintains the lane it is traveling in. In this case, the driving assistance device 10 may allow the preceding vehicle 101 to overtake the other vehicle 102 after the other vehicle 102 has passed in order to resume the following travel control with the preceding vehicle 101 as the following target.

FIG. 11 is a flowchart showing the following cruise control performed by the driving assistance device 10 according to the second embodiment. The driving assistance device 10 according to the second embodiment performs the flow of FIG. 11 in step S3 of FIG. 4.

When step S3 in FIG. 4 is started, first, the following driving control unit 13 determines whether the leading vehicle will overtake another vehicle based on the recognition result of the operation of the leading vehicle by the driving situation recognition unit 12 (step S311).

If the preceding vehicle does not overtake the other vehicle (NO in step S311), the following driving control unit 13 maintains the lane in which the host vehicle 100 is traveling in the same lane as the preceding vehicle, performs following driving control (step S312), and ends the flow in FIG. 11 (transitions to step S4 in FIG. 4).

If the preceding vehicle is about to overtake another vehicle (YES in step S311), the following driving control unit 13 further determines whether or not it is possible for the host vehicle 100 to drive in the same lane as the preceding vehicle when the preceding vehicle is about to overtake the other vehicle, based on the positional relationship between the preceding vehicle, the host vehicle 100, and the surrounding vehicles (step S313). Specifically, it is determined whether or not the host vehicle 100 can change lanes into the same lane when the preceding vehicle changes lanes.

If it is possible for the host vehicle 100 to travel in the same lane as the preceding vehicle (YES in step S313), the following driving control unit 13 determines that the host vehicle 100 will travel in the same lane as the preceding vehicle, and performs following driving control to cause the host vehicle 100 to overtake the other vehicle together with the preceding vehicle (step S314), and ends the flow in FIG. 11.

However, if it is not possible for the host vehicle 100 to travel in the same lane as the preceding vehicle (NO in step S313), the following travel control unit 13 cancels the following travel control with the preceding vehicle as the following target (step S315), and ends the flow in FIG. 11.

In this way, the driving assistance device according to the second embodiment determines whether or not to make the host vehicle 100 travel in a lane different from that of the preceding vehicle, depending on the driving conditions of the preceding vehicle and the host vehicle 100. This helps to prevent the following relationship between the preceding vehicle and the host vehicle 100 from being interrupted.

[Modification 1]
The means by which the traveling condition recognition unit 12 recognizes the overtaking operation of the preceding vehicle by the other vehicle is not limited to the vehicle-to-vehicle communication device 24. For example, the overtaking operation of the preceding vehicle by the other vehicle may be detected from the behavior of the preceding vehicle detected by the periphery detection device 21.

[Modification 2]
The decision as to whether or not to make the host vehicle 100 travel in a lane different from that of the preceding vehicle may be made when the host vehicle 100 performs an overtaking operation for another vehicle.

In this case, the driving condition recognition unit 12 recognizes that another vehicle has cut in between the vehicle 100 and the preceding vehicle traveling in the same lane.

Furthermore, when it is recognized that another vehicle has cut in between the preceding vehicle and the subject vehicle 100, the following driving control unit 13 determines whether it is possible to have the subject vehicle 100 travel in a lane different from that of the preceding vehicle, based on the positional relationship between the preceding vehicle, the subject vehicle 100, and the surrounding vehicles. If it is possible, the following driving control unit 13 determines that the subject vehicle 100 will travel in a lane different from that of the preceding vehicle, and causes the subject vehicle 100 to overtake the other vehicle and the preceding vehicle. The driving assistance device 10 may then request the preceding vehicle to move ahead of the subject vehicle 100 via the vehicle-to-vehicle communication device 24 at an appropriate timing.

If it is not possible for the host vehicle 100 to travel in a lane different from the preceding vehicle, the following driving control unit 13 cancels the following driving control that has the preceding vehicle as the following target.

<Third embodiment>
Fig. 12 is a block diagram showing the configuration of a driving support device 10 according to embodiment 3. The configuration of Fig. 12 is obtained by adding a navigation device 25 connected to the driving support device 10 to the configuration of Fig. 6.

The navigation device 25 searches for a route from the current position of the vehicle 100 to the destination, sets the optimal route as the planned driving route of the vehicle 100, and provides route guidance for the vehicle 100. In this embodiment, the navigation device 25 provides the driving assistance device 10 with information on the planned driving route of the vehicle 100.

In the third embodiment, the driving situation recognition unit 12 recognizes the planned driving route of the preceding vehicle and the vehicle itself 100. Information on the planned driving route of the vehicle itself 100 can be obtained from the navigation device 25. Information on the planned driving route of the preceding vehicle can be obtained from the preceding vehicle through the vehicle-to-vehicle communication device 24.

When the host vehicle 100 is following a preceding vehicle and approaches an intersection, a branch point, or the entrance to a specific facility, the following driving control unit 13 determines whether or not the host vehicle 100 should drive in a lane different from that of the preceding vehicle, based on the planned driving route of the preceding vehicle and the host vehicle 100.

More specifically, when the host vehicle 100 is following a leading vehicle and approaches an intersection or branching point, the following driving control unit 13 determines whether the leading vehicle will turn in the same direction as the host vehicle 100 at the intersection or branching point based on the planned driving route of the leading vehicle and the host vehicle 100.

When the following driving control unit 13 determines that the preceding vehicle is turning in the same direction as the vehicle 100, it determines that the lane in which the vehicle 100 will travel will be the same lane as the preceding vehicle, and performs following driving control. For example, as shown in FIG. 13, when the preceding vehicle 101 and the vehicle 100 both turn left at an intersection, or as shown in FIG. 14, when the preceding vehicle 101 and the vehicle 100 both turn right at an intersection, it determines that the lane in which the vehicle 100 will travel will be the same lane as the preceding vehicle 101.

When the preceding vehicle and the vehicle 100 are both traveling straight at an intersection or branching point, the lane in which the vehicle 100 travels may be the same lane as the preceding vehicle or a different lane. However, from the viewpoint of preventing the following travel control from being interrupted, it is preferable to make the lane in which the vehicle 100 travels the same lane as the preceding vehicle. If the vehicle 100 travels in a lane different from that of the preceding vehicle, it becomes difficult to make the vehicle 100 follow the preceding vehicle, for example, when only the lane of the vehicle 100 is congested or when an obstacle is present only in the lane of the vehicle 100.

In addition, if the following driving control unit 13 determines that the preceding vehicle is moving in a different direction from the host vehicle 100, it cancels the following driving control that has the preceding vehicle as the following target.

FIG. 15 is a flowchart showing the following cruise control performed by the driving assistance device 10 according to the third embodiment. The driving assistance device 10 according to the third embodiment performs the flow of FIG. 15 in step S3 of FIG. 4.

When step S3 in FIG. 4 is started, first, the following driving control unit 13 determines whether the host vehicle 100 is approaching an intersection or a branch point (step S321). The determination of whether the host vehicle 100 is approaching an intersection or a branch point is made, for example, based on whether the distance or the required time from the host vehicle 100 to the intersection or the branch point is equal to or less than a predetermined threshold value.

If the vehicle 100 is not approaching an intersection or branch point (NO in step S321), the following driving control unit 13 performs following driving control to cause the vehicle 100 to follow the preceding vehicle in any lane (step S323), and ends the flow in FIG. 15 (transitions to step S4 in FIG. 4).

If the host vehicle 100 approaches an intersection or branch point (YES in step S321), the following driving control unit 13 further determines whether the preceding vehicle and the host vehicle 100 will both proceed straight at the intersection or branch point based on the planned driving routes of the preceding vehicle and the host vehicle 100 (step S322).

If both the preceding vehicle and the vehicle 100 are traveling straight (YES in step S322), follow-up cruise control is implemented to cause the vehicle 100 to follow the preceding vehicle in any lane (step S323), and the flow in FIG. 15 ends.

If neither the preceding vehicle nor the subject vehicle 100 is traveling straight ahead (NO in step S322), the following driving control unit 13 further determines whether the preceding vehicle and the subject vehicle 100 will both turn in the same direction at an intersection or branch point based on the planned driving routes of the preceding vehicle and the subject vehicle 100 (step S324).

If the preceding vehicle and the vehicle 100 are both turning in the same direction (YES in step S324), the lane in which the vehicle 100 will travel is determined to be the same lane as the preceding vehicle, and follow-up travel control is implemented to make the vehicle 100 follow the preceding vehicle (step S325), and the flow in FIG. 15 ends.

However, if the preceding vehicle and the vehicle 100 are moving in different directions (NO in step S324), the following driving control unit 13 cancels the following driving control with the preceding vehicle as the following target (step S326), and ends the flow in FIG. 15.

In this way, the driving assistance device according to the third embodiment determines whether or not to make the lane in which the host vehicle 100 travels different from that of the preceding vehicle depending on the driving conditions of the preceding vehicle and the host vehicle 100. This helps to prevent the following relationship between the preceding vehicle and the host vehicle 100 from being interrupted.

13 and 14 show an example of turning right or left at an intersection with two lanes on each side, but this embodiment can also be applied to cases where the vehicle 100 is traveling on a road with more lanes. For example, on a road with six lanes on each side, with the two lanes on the left side being lanes for left turns and the two lanes on the right side being lanes for right turns, when both the preceding vehicle and the vehicle 100 are turning left, the driving assistance device 10 may make the vehicle 100 travel in the same left-turn-only lane as the preceding vehicle. If the vehicle 100 travels in a left-turn-only lane different from the preceding vehicle, the possibility that the vehicle 100 will not be able to follow the preceding vehicle due to traffic conditions after the left turn can be reduced. If the vehicle 100 travels in a left-turn-only lane different from the preceding vehicle, for example, when only the lane of the vehicle 100 is congested on the road after the left turn or when an obstacle is present only in the lane of the vehicle 100, it becomes difficult to make the vehicle 100 follow the preceding vehicle. Similarly, when turning right, the driving assistance device 10 should drive the vehicle 100 in the same left-turn lane as the preceding vehicle.

Also, assuming a road with left-hand traffic, since there is a relatively high possibility that travel will be obstructed in the leftmost lane, if the preceding vehicle turns left from the leftmost left-turn dedicated lane, the leftmost left-turn dedicated lane and the second left-turn dedicated lane from the left may be permitted for the host vehicle 100, and if the preceding vehicle turns left from the second left-turn dedicated lane from the left, only the second left-turn dedicated lane from the left (the same lane as the preceding vehicle) may be permitted for the host vehicle 100. In this way, the lanes permitted for the host vehicle 100 may be changed depending on the attributes of the left-turn dedicated lane in which the preceding vehicle is traveling.

In addition, if it is difficult to have the vehicle 100 travel in the same left-turn lane as the preceding vehicle due to the influence of other vehicles, the vehicle may travel in a different left-turn lane than the preceding vehicle, rather than forcing the vehicle to travel in the same left-turn lane as the preceding vehicle.

The procedure for turning right is the same as for turning left. However, there are also right-turn lanes where the vehicle travels in the leftmost lane of the road after turning right. For example, if there are two right-turn lanes and the second right-turn lane from the right (i.e. the right-turn lane on the left) is connected to the leftmost lane of the road after turning right, then if the preceding vehicle is traveling in the rightmost right-turn lane, then the vehicle 100 may be allowed to use only the rightmost right-turn lane (the same lane as the preceding vehicle), and if the preceding vehicle is traveling in the second right-turn lane from the right, then the vehicle 100 may be allowed to use both the rightmost right-turn lane and the second right-turn lane from the right.

[Modification]
The decision as to whether to drive the vehicle 100 in a lane different from that of the preceding vehicle may be made when the preceding vehicle and the vehicle 100 approach the entrance to a particular facility (e.g., a commercial facility, a service area on a highway, a parking area, etc.).

In this case, the following driving control unit 13 determines whether the next facility at which the preceding vehicle 101 will stop is the same as the next facility at which the host vehicle 100 will stop, based on the planned driving routes of the preceding vehicle 101 and the host vehicle 100. If the next facility at which the preceding vehicle 101 will stop is the same as the next facility at which the host vehicle 100 will stop, the following driving control unit 13 determines that the lane in which the host vehicle 100 will travel will be the same as that of the preceding vehicle 101 when approaching the entrance to the facility. However, if the next facility at which the preceding vehicle 101 will stop is different from the next facility at which the host vehicle 100 will stop, the following driving control unit 13 cancels the following driving control with the preceding vehicle 101 as the follow-up target when approaching the entrance to either of the facilities.

When the driving assistance device 10 stops at the same facility as the preceding vehicle, it can continue follow-up driving control even when entering the entrance of the facility, thereby achieving smooth follow-up driving.

In the first to third embodiments, the preceding vehicle may be any vehicle, but for example, the host vehicle 100 and the preceding vehicle may be two vehicles traveling in a group. In group traveling, when the following vehicle travels in a different lane from the preceding vehicle and the following vehicle ends up traveling ahead of the preceding vehicle, the relationship between the preceding vehicle and the following vehicle may be swapped. For example, the following vehicle may be ahead of the preceding vehicle when another vehicle cuts in between the preceding vehicle and the following vehicle, when another vehicle is overtaken, when only some lanes are congested, etc. Compared to the case where the host vehicle 100 is always the following vehicle, the control for reconstructing the following relationship is simplified.

<Hardware configuration example>
16 and 17 are diagrams showing examples of the hardware configuration of the driving support device 10. The functions of the components of the driving support device 10 shown in FIG. 1 are realized, for example, by a processing circuit 50 shown in FIG. 16. That is, the driving support device 10 recognizes a preceding vehicle to be followed by the vehicle 100, recognizes the traveling conditions of the preceding vehicle and the vehicle 100, performs following travel control to make the vehicle 100 travel following the preceding vehicle, and, when performing the following travel control, includes a processing circuit 50 for determining whether or not to make the lane in which the vehicle 100 travels different from the lane in which the preceding vehicle travels based on the traveling conditions of the preceding vehicle and the vehicle 100. The processing circuit 50 may be a dedicated hardware, or may be configured using a processor (also called a central processing unit (CPU), processing device, arithmetic device, microprocessor, microcomputer, or DSP (Digital Signal Processor)) that executes a program stored in a memory.

When the processing circuit 50 is dedicated hardware, the processing circuit 50 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination of these. Each function of the components of the driving assistance device 10 may be realized by a separate processing circuit, or these functions may be realized together by a single processing circuit.

17 shows an example of the hardware configuration of the driving assistance device 10 in the case where the processing circuit 50 is configured using a processor 51 that executes a program. In this case, the functions of the components of the driving assistance device 10 are realized by software, etc. (software, firmware, or a combination of software and firmware). The software, etc. is written as a program and stored in the memory 52. The processor 51 realizes the functions of each part by reading and executing the program stored in the memory 52. That is, the driving assistance device 10 has a memory 52 for storing a program that, when executed by the processor 51, results in the execution of the following processes: a process of recognizing a preceding vehicle to be followed by the host vehicle 100, a process of recognizing the driving conditions of the preceding vehicle and the host vehicle 100, a process of performing follow-up driving control to cause the host vehicle 100 to follow the preceding vehicle, and a process of determining whether or not to set the lane in which the host vehicle 100 will travel to be a lane different from that of the preceding vehicle, based on the driving conditions of the preceding vehicle and the host vehicle 100, when performing the follow-up driving control. In other words, this program causes the computer to execute procedures and methods for the operation of the components of the driving assistance device 10.

Here, memory 52 may be, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), HDD (Hard Disk Drive), magnetic disk, flexible disk, optical disk, compact disk, mini disk, DVD (Digital Versatile Disc) and their drive devices, or any other storage medium that will be used in the future.

The above describes a configuration in which the functions of the components of the driving assistance device 10 are realized either by hardware or software, etc. However, this is not limited to the above, and the configuration may be such that some of the components of the driving assistance device 10 are realized by dedicated hardware, and other components are realized by software, etc. For example, it is possible for the functions of some components to be realized by the processing circuit 50 as dedicated hardware, and for other components, the functions to be realized by the processing circuit 50 as the processor 51 reading and executing a program stored in the memory 52.

As described above, the driving assistance device 10 can realize each of the above-mentioned functions through hardware, software, etc., or a combination of these.

In addition, it is possible to freely combine each embodiment, and to modify or omit each embodiment as appropriate.

The above description is illustrative in all respects, and it is understood that countless variations not illustrated may be envisioned.

10 Driving assistance device, 11 Leading vehicle recognition unit, 12 Driving situation recognition unit, 13 Following driving control unit, 20 Driving control device, 21 Surrounding detection device, 22 Locator, 23 Road-to-vehicle communication device, 24 Vehicle-to-vehicle communication device, 25 Navigation device, 50 Processing circuit, 51 Processor, 52 Memory, 100 Vehicle, 101 Leading vehicle, 102, 103 Other vehicles.

Claims (12)

a preceding vehicle recognition unit that recognizes a preceding vehicle to be followed by the host vehicle;
a driving condition recognition unit that recognizes driving conditions of the preceding vehicle and the host vehicle;
a following driving control unit that performs a following driving control for causing the host vehicle to follow the preceding vehicle;
Equipped with
the following driving control unit determines whether or not to make the host vehicle travel in a lane different from that of the preceding vehicle based on driving conditions of the preceding vehicle and the host vehicle when performing the following driving control;
Driving assistance device. The driving situation recognition unit recognizes a positional relationship between the preceding vehicle and the host vehicle and a specific road facility,
the following driving control unit determines whether or not to set a lane in which the host vehicle will travel when following the preceding vehicle and passing through the specific road facility to a lane different from that of the preceding vehicle;
The driving assistance device according to claim 1 . the driving situation recognition unit recognizes a positional relationship between the preceding vehicle and the host vehicle and a traffic light, which is the specific road facility, and traffic light information including information on a timing at which an indication of the traffic light is changed;
the following driving control unit calculates the timing when each of the preceding vehicle and the host vehicle will arrive at the traffic light based on the positional relationship between the preceding vehicle, the host vehicle, and the traffic light, and calculates the timing when the traffic light will switch to a stop instruction based on the traffic light information; if it determines that the timing when the traffic light will switch to a stop instruction will be between the timing when the preceding vehicle arrives at the traffic light and the timing when the host vehicle arrives at the traffic light, it determines a lane in which the host vehicle will travel in a lane different from that of the preceding vehicle, and causes the host vehicle to pass through the traffic light side by side with the preceding vehicle.
The driving assistance device according to claim 2 . The driving situation recognition unit further recognizes a positional relationship between the preceding vehicle and the host vehicle and surrounding vehicles,
Even if the following travel control unit determines that the timing at which the traffic light switches to a stop instruction will be between the timing at which the preceding vehicle arrives at the traffic light and the timing at which the host vehicle arrives at the traffic light, if the following travel control unit determines that the host vehicle cannot pass through the traffic light side by side with the preceding vehicle based on a positional relationship between the preceding vehicle, the host vehicle, and the surrounding vehicles, the following travel control unit cancels the following travel control for the preceding vehicle to be followed.
The driving assistance device according to claim 3. the driving condition recognition unit recognizes a positional relationship between the preceding vehicle and the vehicle itself and a toll gate which is the specific road facility, and toll gate information including information on the number of gates at the toll gate and the congestion level around each gate,
The following driving control unit calculates, based on the toll gate information, a first time difference which is a difference in timing at which the preceding vehicle and the host vehicle pass through the toll gate when the gate through which the host vehicle passes is the same as that of the preceding vehicle, and a second time difference which is a difference in timing at which the preceding vehicle and the host vehicle pass through the toll gate when the gate through which the host vehicle passes is a gate different from that of the preceding vehicle, and if it determines that the second time difference is smaller than the first time difference, determines that a lane in which the host vehicle will travel will be a lane different from that of the preceding vehicle, and causes the host vehicle to pass through a gate different from that of the preceding vehicle.
The driving assistance device according to claim 2 . The driving condition recognition unit recognizes a positional relationship between the preceding vehicle and the host vehicle and surrounding vehicles,
the following driving control unit determines, when the preceding vehicle or the host vehicle is to overtake another vehicle, whether or not to make the host vehicle travel in a lane different from that of the preceding vehicle, based on a positional relationship between the preceding vehicle and the host vehicle and the surrounding vehicles;
The driving assistance device according to claim 1 . The traveling condition recognition unit recognizes an overtaking operation of the preceding vehicle by the other vehicle,
The following driving control unit determines whether or not it is possible to cause the host vehicle to travel in the same lane as the preceding vehicle when the preceding vehicle overtakes the other vehicle, based on a positional relationship between the preceding vehicle and the host vehicle and the surrounding vehicles, and if possible, determines the lane in which the host vehicle will travel to be the same lane as the preceding vehicle, and causes the host vehicle to follow the preceding vehicle and overtake the other vehicle, and if not possible, cancels the following driving control with the preceding vehicle as the follow-up target.
The driving assistance device according to claim 6. The driving condition recognition unit recognizes an intrusion of another vehicle between the preceding vehicle and the host vehicle traveling in the same lane,
The following driving control unit determines whether or not it is possible to cause the host vehicle to travel in a lane different from that of the preceding vehicle based on a positional relationship between the preceding vehicle and the host vehicle and the surrounding vehicles, and if possible, determines a lane in which the host vehicle will travel to be a lane different from that of the preceding vehicle, and causes the host vehicle to overtake the other vehicle and the preceding vehicle, and if not possible, cancels the following driving control with the preceding vehicle as the following target.
The driving assistance device according to claim 6. The driving situation recognition unit recognizes a planned driving route of the preceding vehicle and the host vehicle,
the following driving control unit, when the host vehicle approaches an intersection, a branch point, or an entrance to a specific facility while following the preceding vehicle, determines whether or not to make the host vehicle travel in a lane different from that of the preceding vehicle based on the planned travel route of the preceding vehicle and the host vehicle;
The driving assistance device according to claim 1 . the following driving control unit, when the host vehicle approaches the intersection or the branch point while following the preceding vehicle, determines whether the preceding vehicle will turn in the same direction as the host vehicle at the intersection or the branch point, based on the preceding vehicle and the planned driving route of the host vehicle, and if it determines that the preceding vehicle will turn in the same direction as the host vehicle, determines the same lane as the preceding vehicle as the lane in which the host vehicle will travel, and if it determines that the preceding vehicle will proceed in a direction different from that of the host vehicle, cancels the following driving control with the preceding vehicle as the target to be followed.
A driving assistance device according to claim 9. The following travel control unit determines whether or not a facility at which the preceding vehicle will next stop is the same as a facility at which the host vehicle will next stop, based on the planned travel route of the preceding vehicle and the host vehicle, and if the facility at which the preceding vehicle will next stop is the same as the facility at which the host vehicle will next stop, determines the lane in which the host vehicle will travel to be the same as the lane in which the preceding vehicle will travel when approaching an entrance to the facility, and if the facility at which the preceding vehicle will next stop is different from the facility at which the host vehicle will next stop, cancels the following travel control with the preceding vehicle as the target to be followed when approaching an entrance to either of the facilities.
A driving assistance device according to claim 9. A preceding vehicle recognition unit of the driving support device recognizes a preceding vehicle that the host vehicle is to follow,
a driving situation recognition unit of the driving assistance device recognizes driving situations of the preceding vehicle and the host vehicle,
a following driving control unit of the driving assistance device performs a following driving control for causing the host vehicle to follow the preceding vehicle;
the following driving control unit determines whether or not to make the host vehicle travel in a lane different from that of the preceding vehicle based on travel conditions of the preceding vehicle and the host vehicle when performing the following driving control;
Driving assistance methods.

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