Vehicle driving support device

Abstract

To provide a vehicle driving support device in which an own vehicle can secure travel safety of the own vehicle in a branch passage without impeding traffic flow of the main track of a freeway.SOLUTION: A vehicle driving support device 10 executes tracking travel control which makes an own vehicle 100 travel automatically so as to track a preceding vehicle 200F. The vehicle driving support device executes separation control which increases a vehicular gap between the own vehicle and the preceding vehicle automatically when ending the tracking travel control when the own vehicle travels on a main track 300M of a freeway 300. The vehicle driving support device executes the separation control after the own vehicle enters a branch passage 300B of the freeway if the preceding vehicle enters the branch passage in the case of ending the tracking travel control when it is identified that the own vehicle enters from the main track of the freeway into the branch passage within a prescribed time.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle driving assistance device. [Background technology]

[0002] There is known a vehicle driving assistance device that automatically drives a plurality of vehicles in a platoon. Another known vehicle driving assistance device is configured to automatically increase the inter-vehicle distance between the host vehicle and a vehicle immediately preceding the host vehicle in the platoon (a preceding vehicle) in order to ensure the safety of the host vehicle until the host vehicle has completely left the platoon (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-273588 Summary of the Invention

[0004] Incidentally, when a host vehicle is traveling automatically in a convoy with other vehicles on a main lane of a highway, there may be a situation where the host vehicle leaves the convoy to enter a branch lane of the highway. In this case, the following vehicle may also decelerate before the branch lane in an attempt to enter the same branch lane. In this case, if the inter-vehicle distance between the host vehicle and the following vehicle is automatically increased to ensure the traveling safety of the host vehicle, the host vehicle will decelerate significantly, which may result in disruption of traffic flow on the main lane of the highway. This possibility exists even when the host vehicle is traveling automatically on the main lane of the highway to follow the leading vehicle.

[0005] An object of the present invention is to provide a vehicle driving assistance system that can ensure the safe running of a vehicle on a branch lane without disrupting traffic flow on the main lane of a highway.

[0006] A vehicle driving assistance device according to the present invention includes a control device that executes follow-up cruise control to automatically cause a host vehicle to follow a preceding vehicle. The control device is configured to execute separation control to automatically increase the inter-vehicle distance between the host vehicle and the preceding vehicle when the follow-up cruise control is terminated while the host vehicle is traveling on a main lane of a highway. The control device is further configured to execute separation control after the host vehicle has entered the branch lane if the follow-up cruise control is terminated when it is known that the host vehicle will enter a branch lane of the highway from the main lane within a predetermined time.

[0007] When a vehicle is traveling on a main lane of a highway using adaptive cruise control, the vehicle may enter a branch lane on the highway. At this time, the vehicle ahead may also attempt to enter the same branch lane and decelerate before the branch lane. In this case, if the vehicle-to-vehicle distance is automatically increased to ensure the vehicle's driving safety, the vehicle will decelerate significantly, which may result in disruption of traffic flow on the main lane of the highway.

[0008] According to the vehicle driving assistance system of the present invention, the inter-vehicle distance is increased after the host vehicle enters the branch lane. Therefore, the inter-vehicle distance is not increased while the host vehicle is traveling on the main lane of the expressway. This ensures the safe traveling of the host vehicle on the branch lane without disrupting traffic flow on the main lane of the expressway.

[0009] In addition, in the vehicle driving assistance device of the present invention, the control device can be configured to create a target driving route to a destination set by the driver of the vehicle, and if it is determined based on the target driving route that the vehicle will enter a branch road of the expressway from the main road within the specified time, make an end proposal to the driver to end the following driving control, and if the driver performs an approval operation to approve the end proposal, end the following driving control.

[0010] According to the vehicle driving assistance system of the present invention, when it is determined based on the target driving route that the vehicle will enter a branch lane from the main lane of the expressway within a predetermined time, it is suggested to terminate the following cruise control, thereby enabling the driver to know that it is necessary to terminate the following cruise control at an appropriate time.

[0011] Furthermore, in the vehicle driving assistance device according to the present invention, the following driving control is, for example, convoy driving control that automatically drives the host vehicle so that multiple vehicles including the host vehicle drive in a line in the same lane.

[0012] Generally, when a vehicle is traveling under platooning control, the vehicle travels with a relatively short inter-vehicle distance. Therefore, in order to ensure the traveling safety of the vehicle, it is desirable to execute separation control when the platooning control is terminated.

[0013] According to the vehicle driving assistance device of the present invention, when platooning control is terminated, separation control is executed after the vehicle enters the branch lane, thereby ensuring the driving safety of the vehicle without disrupting traffic flow on the main lane of the expressway.

[0014] The components of the present invention are not limited to the embodiments of the present invention described below with reference to the drawings. Other objects, features, and attendant advantages of the present invention will be easily understood from the description of the embodiments of the present invention. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing a vehicle driving assistance device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a scene in which a plurality of vehicles including the vehicle in question are traveling in a convoy. [Figure 3] FIG. 3 is a flowchart showing a routine executed by the vehicle driving assistance device according to the embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing a scene in which the vehicle enters a branching road. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a vehicle driving assistance device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a vehicle driving assistance device 10 according to an embodiment of the present invention. The vehicle driving assistance device 10 is mounted on a host vehicle 100. Hereinafter, the vehicle driving assistance device 10 will be described using an example in which the operator of the host vehicle 100 is a person who is in the host vehicle 100 and drives the host vehicle 100 (i.e., the driver of the host vehicle 100). However, the operator of the host vehicle 100 may also be a person who is not in the host vehicle 100 and drives the host vehicle 100 remotely (i.e., a remote operator of the host vehicle 100). Furthermore, the present invention is applicable to vehicles that are driven only by automatic driving control, as well as vehicles that are driven by manual driving operation and automatic driving control.

[0017] As shown in FIG. 1, the vehicle driving assistance device 10 includes an ECU (electronic control unit) 90 as a control device. The ECU 90 includes a microcomputer as a main component. The microcomputer includes a CPU, storage media such as a ROM, a RAM, and a non-volatile memory, as well as an interface. The CPU executes instructions, programs, or routines stored in the storage media to realize various functions. In particular, in this example, the vehicle driving assistance device 10 stores programs in the storage media that realize various controls executed by the vehicle driving assistance device 10.

[0018] In this example, the vehicle driving assistance device 10 includes only one ECU 90, but may include multiple ECUs, each of which performs a part of the functions of the vehicle driving assistance device 10 described below. The vehicle driving assistance device 10 may also be configured to be able to update a program stored in a storage medium via wireless communication with an external device (for example, via the Internet).

[0019] As shown in FIG. 1, the vehicle 100 is equipped with a driving device 20, a braking device 30, a notification device 40, a driving assistance operation device 51, an approval operation device 52, a vehicle speed detection device 60, a surrounding information detection device 70, a navigation device 81, a GPS receiver 82, and a map database 83.

[0020] The drive unit 20 is a device that generates a drive force to be applied to the host vehicle 100 (particularly, the drive wheels of the host vehicle 100). In this example, the drive unit 20 includes an internal combustion engine 21 and a motor 22. The drive unit 20 is electrically connected to the ECU 90. The vehicle driving assistance device 10 can control the drive force to be applied to the host vehicle 100 by controlling the operation of the drive unit 20 (i.e., the internal combustion engine 21 and the motor 22).

[0021] The braking device 30 is a device that applies braking force to the host vehicle 100 (particularly, the wheels of the host vehicle 100). The braking device 30 is, for example, a hydraulic brake device. The braking device 30 is electrically connected to the ECU 90. The vehicle driving assistance device 10 can control the braking force applied to the host vehicle 100 by controlling the operation of the braking device 30.

[0022] The notification device 40 is a device that provides various notifications to the driver. In this example, the notification device 40 includes an audio device 41 and a display device 42. The audio device 41 includes a speaker. The audio device 41 is electrically connected to the ECU 90. The vehicle driving assistance device 10 can provide various notifications by outputting sounds from the audio device 41. The display device 42 includes a display. The display device 42 is electrically connected to the ECU 90. The vehicle driving assistance device 10 can provide various notifications by displaying images on the display device 42.

[0023] The driving assistance operating device 51 is a device such as a switch that is operated by the driver to request the execution or termination of platooning control, which will be described later. The driving assistance operating device 51 is electrically connected to the ECU 90. In this example, if the driving assistance operating device 51 is operated when platooning control is not being executed, the vehicle driving assistance device 10 determines that the execution of platooning control has been requested. On the other hand, if the driving assistance operating device 51 is operated when platooning control is being executed, the vehicle driving assistance device 10 determines that the termination of platooning control has been requested.

[0024] The approval operation device 52 is a device such as a switch that is operated by the driver to approve a termination proposal, which will be described later. The approval operation device 52 is electrically connected to the ECU 90. When the approval operation device 52 is operated by the driver when a termination proposal, which will be described later, is implemented, the vehicle driving assistance device 10 determines that the driver has approved the termination proposal.

[0025] The vehicle speed detection device 60 is a device that detects the traveling speed of the host vehicle 100. The vehicle speed detection device 60 includes, for example, wheel speed sensors provided on each wheel of the host vehicle 100. The vehicle speed detection device 60 is electrically connected to the ECU 90. The vehicle driving assistance device 10 acquires the traveling speed of the host vehicle 100 as the host vehicle speed Vego using the vehicle speed detection device 60.

[0026] The surrounding information detection device 70 is a device that detects information about the surroundings of the host vehicle 100. In this example, the surrounding information detection device 70 includes an electromagnetic wave sensor 61 and an image sensor 62. The electromagnetic wave sensor 61 and the image sensor 62 are electrically connected to the ECU 90. The electromagnetic wave sensor 61 is, for example, a radar sensor such as a millimeter-wave radar. The vehicle driving assistance device 10 acquires information about objects present in the surroundings of the host vehicle 100 as surrounding information IS using the electromagnetic wave sensor 61. Furthermore, the image sensor 62 is, for example, a camera sensor. The vehicle driving assistance device 10 acquires image information about the surroundings of the host vehicle 100 as surrounding information IS using the image sensor 62.

[0027] The navigation device 81 is a device that guides the driver along a driving route of the vehicle 100 to a destination set by the driver. The driver can set the destination using the navigation device 81. The navigation device 81 is electrically connected to the ECU 90. The vehicle driving assistance device 10 creates a driving route (or a driving plan) to the destination set by the driver as a target driving route Rtgt.

[0028] The GPS receiver 82 is a device that receives GPS signals. The GPS receiver 82 is electrically connected to the ECU 90. The vehicle driving assistance device 10 receives the GPS signals via the GPS receiver 82.

[0029] The map database 83 is a database that stores map information. The map database 83 is electrically connected to the ECU 90.

[0030] The vehicle driving assistance device 10 identifies the current position Pnow of the vehicle 100 based on the GPS signal received via the GPS receiver 82, compares the current position Pnow with map information in the map database 83, identifies the position of the vehicle 100 on the map, and provides guidance on the route along which the vehicle 100 should travel based on the created target travel route Rtgt using the navigation device 81. The vehicle driving assistance device 10 provides guidance on the route along which the vehicle 100 should travel by displaying a map of the area around the vehicle 100 using the navigation device 81, displaying the target travel route Rtgt on the map, and outputting voice guidance, for example.

[0031] <Operation of vehicle driving assistance device> Next, we will explain the operation of the vehicle driving assistance device 10. When the vehicle driving assistance device 10 determines that execution of platooning control has been requested, it executes platooning control as automatic driving control. On the other hand, when the vehicle driving assistance device 10 determines that termination of platooning control has been requested, it terminates platooning control.

[0032] Platooning control is control that automatically causes a plurality of vehicles 200, including the host vehicle 100, to travel in a line in the same lane, as shown in Fig. 2. In other words, platooning control is control that automatically causes a plurality of vehicles 200, including the host vehicle 100, to travel in a line.

[0033] In this example, when executing platooning control, the vehicle driving assistance device 10 causes the host vehicle 100 to travel while automatically or autonomously switching between powering control and coasting control so that the inter-vehicle distance D between the host vehicle 100 and a vehicle 200 (following preceding vehicle 200F) traveling immediately ahead of the host vehicle 100 is maintained within a set inter-vehicle distance range RD. Therefore, the platooning control is one type of following travel control that automatically causes the host vehicle 100 to travel so as to follow the preceding vehicle. Note that, when executing platooning control, the vehicle driving assistance device 10 may be configured to wirelessly communicate with the vehicles 200 traveling in a line, acquire the traveling states of these vehicles 200, and cause the host vehicle 100 to travel while taking the acquired traveling states into consideration.

[0034] Powering control is control in which driving force is applied from the drive unit 20 to the host vehicle 100 to power the host vehicle 100. In particular, powering control is optimal powering control in which driving force is applied from the drive unit 20 to the host vehicle 100 while operating the drive unit 20 at optimal energy efficiency, to power the host vehicle 100. On the other hand, coasting control is control in which the drive force applied from the drive unit 20 to the host vehicle 100 is set to zero by disconnecting the connection between the drive unit 20 and the drive wheels of the host vehicle 100, thereby coasting the host vehicle 100.

[0035] The following preceding vehicle 200F is another vehicle traveling in the same lane as the host vehicle 100, and is present within a predetermined distance ahead of the host vehicle 100. The vehicle driving assistance device 10 determines whether or not the following preceding vehicle 200F exists based on the surrounding information IS. The vehicle driving assistance device 10 also acquires the inter-vehicle distance D based on the surrounding information IS.

[0036] In this example, the set inter-vehicle distance range RD is a range in which the set inter-vehicle distance Dset has a lower limit value Dlower and an upper limit value Dupper that is a distance that is longer than the set inter-vehicle distance Dset by a predetermined width WD (or a predetermined value). The set inter-vehicle distance Dset is a distance that is set in advance. The predetermined width WD may be a constant value that is independent of the host vehicle speed Vego, or may be a value that varies depending on the host vehicle speed Vego, specifically, a value that increases as the host vehicle speed Vego increases.

[0037] In this example, the set inter-vehicle distance Dset during execution of the platooning control is set to a distance shorter than the set inter-vehicle distance Dset during execution of the normal follow-up cruise control or the eco-follow-up cruise control. Here, the normal follow-up cruise control and the eco-follow-up cruise control do not automatically cause the host vehicle 100 to travel in a line with multiple vehicles 200 including the host vehicle 100 so that these vehicles 200 travel in the same lane, but simply cause the host vehicle 100 to travel automatically so that it follows only the vehicle (preceding vehicle) traveling just before the host vehicle 100. In particular, the normal follow-up cruise control is a control that automatically causes the host vehicle 100 to travel so that the inter-vehicle distance D is maintained at the set inter-vehicle distance Dset. Furthermore, the eco-follow-up cruise control is a control that automatically switches between powering control and coasting control so that the inter-vehicle distance D is maintained within the set inter-vehicle distance range RD.

[0038] When platooning control is being performed, if the inter-vehicle distance D becomes longer than the upper limit value Dupper of the set inter-vehicle distance range RD, the vehicle driving assistance device 10 starts powering control. On the other hand, when platooning control is being performed, if the inter-vehicle distance D becomes shorter than the lower limit value Dlower of the set inter-vehicle distance range RD, the vehicle driving assistance device 10 starts coasting control.

[0039] In this example, when the vehicle speed Vego increases to a set vehicle speed Vset during platooning control, the vehicle driving assistance device 10 autonomously or automatically controls the operation of the drive device 20 and the braking device 30 to maintain the vehicle speed Vego at the set vehicle speed Vset, causing the vehicle 100 to travel. The set vehicle speed Vset is a vehicle speed that is set in advance.

[0040] In addition, the vehicle driving assistance device 10 is configured to execute the routine shown in Figure 3 at predetermined time intervals, and when predetermined conditions are met, to terminate the platooning control and execute separation control to increase the inter-vehicle distance D.

[0041] At a predetermined timing, the vehicle driving assistance device 10 starts the process from step S300 of the routine shown in FIG. 3, and proceeds to step S305 to determine whether or not the separation control is on standby.

[0042] If the determination in step S305 is "No," the vehicle driving assistance device 10 proceeds to step S310 and determines whether or not platooning control is being executed.

[0043] If the vehicle driving assistance device 10 determines "Yes" in step S310, the process proceeds to step S315, where it determines whether or not a proposal condition C1 is satisfied. The proposal condition C1 is a condition that the host vehicle 100 is traveling on the main lane 300M of the expressway 300, route guidance for the host vehicle 100 is being provided based on the target driving route Rtgt, and the host vehicle 100 will enter a branch road 300B from the main lane 300M of the expressway 300 within a predetermined time Tth. The vehicle driving assistance device 10 determines whether or not the host vehicle 100 will enter a branch road 300B from the main lane 300M of the expressway 300 within the predetermined time Tth based on the target driving route Rtgt and the current position Pnow of the host vehicle 100. The branch road 300B is a road that branches off from the main lane 300M of the expressway 300, as shown in FIG. 4. The branch road 300B is, for example, a road that connects the main road 300M of the expressway 300 with an exit of the expressway 300.

[0044] If the determination in step S315 is "Yes," the vehicle driving assistance device 10 proceeds to step S320 and makes an end suggestion. The end suggestion is a suggestion to the driver to end the platooning control. The vehicle driving assistance device 10 makes the end suggestion via the notification device 40.

[0045] Next, the vehicle driving assistance device 10 proceeds to step S325 to determine whether or not an approval operation has been performed by the driver. The approval operation is an operation on the approval operation unit 52 by the driver.

[0046] If the vehicle driving assistance device 10 determines "Yes" in step S325, the process proceeds to step S330, where the platooning control is terminated. Next, the vehicle driving assistance device 10 proceeds to step S335, where a control termination notification is issued. The control termination notification is a notification that notifies the driver that the platooning control has been terminated. The vehicle driving assistance device 10 issues the control termination notification via the notification device 40. Next, the vehicle driving assistance device 10 proceeds to step S340, where it determines whether or not a separation start condition C2 is met. As shown in FIG. 4, the separation start condition C2 is a condition in which the host vehicle 100 has entered the branch road 300B and the following preceding vehicle 200F has also entered the branch road 300B.

[0047] If the driver promptly accepts the proposal to terminate the vehicle 100, the vehicle 100 has not yet entered the branch road 300B. In this case, the vehicle driving assistance device 10 determines "No" in step S340, proceeds to step S395, and temporarily ends the processing of this routine. As a result, the separation control is put on standby.

[0048] Therefore, when the vehicle driving assistance device 10 subsequently proceeds to step S305, it determines "Yes" in step S305, proceeds to step S340, and again determines whether the separation start condition C2 is met.

[0049] If the separation start condition C2 is satisfied, the vehicle driving assistance device 10 determines "Yes" in step S340, proceeds to step S345, and executes separation control. Next, the vehicle driving assistance device 10 proceeds to step S395, and temporarily ends the processing of this routine.

[0050] The separation control is a control for increasing the inter-vehicle distance D between the following preceding vehicle 200F and the host vehicle 100. For example, when the host vehicle speed Vego is equal to or greater than the vehicle speed Vpre of the following preceding vehicle 200F, the vehicle driving assistance device 10 increases the inter-vehicle distance D by decelerating the host vehicle 100 until the host vehicle speed Vego becomes smaller than the vehicle speed Vpre of the following preceding vehicle 200F. On the other hand, when the host vehicle speed Vego is smaller than the vehicle speed Vpre of the following preceding vehicle 200F, the vehicle driving assistance device 10 increases the inter-vehicle distance D by maintaining the host vehicle speed Vego smaller than the vehicle speed Vpre of the following preceding vehicle 200F.

[0051] Furthermore, if the driver performs an approval operation after the termination proposal is made and the vehicle 100 enters the branch road 300B, the vehicle driving assistance device 10 judges the answer to be "Yes" when the processing proceeds from step S335 to step S340, proceeds to step S345, and executes separation control.

[0052] In this way, when the vehicle driving assistance device 10 terminates the platoon driving control when it is known that the vehicle 100 will enter the branch road 300B of the expressway 300 from the main road 300M within a predetermined time Tth, if the following preceding vehicle 200F enters the branch road 300B, the vehicle driving assistance device 10 is configured to perform separation control after the vehicle 100 enters the branch road 300B.

[0053] In addition, the vehicle driving assistance device 10 creates a target driving route Rtgt to the destination set by the driver, and if it is determined based on the target driving route Rtgt that the vehicle 100 will enter the branch road 300B of the expressway 300 from the main road 300M of the expressway 300 within a predetermined time Tth, it makes an end proposal to the driver to end the platoon driving control, and if the driver performs an approval operation to approve the end proposal, it is configured to end the platoon driving control.

[0054] If the vehicle driving assistance device 10 determines "No" in step S310, step S315, or step S325, the process proceeds to step S395 and temporarily ends the process of this routine.

[0055] The above is the operation of the vehicle driving assistance device 10. When the vehicle driving assistance device 10 terminates the platooning control while the vehicle 100 is traveling on the main lane 300M of the expressway 300, if it is not determined that the vehicle 100 will enter the branch road 300B within the predetermined time Tth, the vehicle driving assistance device 10 executes separation control simultaneously with the termination of the platooning control or promptly after the termination of the platooning control.

[0056] When platoon traveling control is being executed, there may be a situation where the host vehicle 100 leaves the platoon to enter a branch road 300B of the expressway 300. At this time, the following leading vehicle 200F may also decelerate before the branch road 300B in an attempt to enter the same branch road 300B. If the inter-vehicle distance D is automatically increased at this time to ensure the traveling safety of the host vehicle 100, the host vehicle 100 will decelerate significantly, which may result in disruption of traffic flow on the main road 300M of the expressway 300.

[0057] According to the vehicle driving assistance device 10, the inter-vehicle distance D is increased after the host vehicle 100 enters the branch road 300B. Therefore, the inter-vehicle distance D is not increased when the host vehicle 100 is traveling on the main road 300M of the expressway 300. This makes it possible to ensure the safe traveling of the host vehicle 100 on the branch road 300B without disrupting the traffic flow on the main road 300M of the expressway 300.

[0058] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0059] For example, the present invention is applicable to the case where the above-described normal follow-up cruise control or eco-follow-up cruise control is being executed, particularly when the above-described normal follow-up cruise control or eco-follow-up cruise control is being executed with a relatively short set inter-vehicle distance Dset. [Explanation of symbols]

[0060] 10...vehicle driving assistance device, 20...drive device, 30...braking device, 40...notification device, 51...driving assistance operation device, 52...approval operation device, 60...vehicle speed detection device, 70...surrounding information detection device, 81...navigation device, 82...GPS receiver, 83...map database, 90...ECU, 100...host vehicle, 200...vehicle, 200F...following preceding vehicle

Claims

1. A control device is provided that executes follow-up driving control to automatically drive the vehicle so as to follow the preceding vehicle, the control device is configured to, when the following cruise control is terminated while the host vehicle is traveling on a main lane of a highway, execute a separation control to automatically increase a vehicle-to-vehicle distance between the host vehicle and the preceding vehicle. In a vehicle driving assistance device, the control device is configured to terminate the following cruise control when it is known that the host vehicle will enter a branch road of the expressway from a main road within a predetermined time, and when the preceding vehicle enters the branch road, to execute the separation control after the host vehicle enters the branch road. Vehicle driving assistance device.

2. The vehicle driving assistance device according to claim 1, The control device creating a target driving route to a destination set by the driver of the vehicle; When it is determined based on the target driving route that the vehicle will enter a branch road of the expressway from a main road of the expressway within the predetermined time, an end suggestion is made to the driver to end the following driving control; When the driver performs an approval operation to approve the termination proposal, the following cruise control is terminated. It is configured as follows: Vehicle driving assistance device.

3. 3. The vehicle driving assistance device according to claim 1, The following driving control is a convoy driving control that automatically drives the host vehicle so that a plurality of vehicles including the host vehicle drive in a line in the same lane. Vehicle driving assistance device.

Images