JP7754055B2 - Driving assistance system - Google Patents

Description

The present invention relates to a driving assistance system.

Conventionally, one such driving assistance system proposed is one that supports the driving of a platoon of vehicles consisting of multiple vehicles traveling in a convoy (see, for example, Patent Document 1). In this system, when a vehicle cuts in on the convoy, the convoy is divided into a first convoy in front of the cutting vehicle and a second convoy behind the cutting vehicle, and an instruction is sent to the lead vehicle of the second convoy to cut in front of it.

International Publication No. 2021/186520

However, the above-mentioned driving assistance system does not provide driving assistance to vehicles cutting in. If a vehicle cutting in switches between manual driving mode operated by the driver and autonomous driving mode not operated by the driver, attempting to cut in while switching driving modes may result in the vehicle's behavior becoming unstable and preventing a smooth cut-in.

The primary purpose of the driving assistance system of the present invention is to enable a vehicle traveling parallel to a platoon of multiple vehicles to smoothly cut into the platoon.

The driving assistance system of the present invention employs the following measures to achieve the above-mentioned primary objective.

The driving assistance system of the present invention comprises:
A driving assistance system that supports the driving of a vehicle that travels alongside a platoon of vehicles that are traveling in a platoon and is capable of switching between driving in a manual driving mode operated by a driver and driving in an automatic driving mode not operated by the driver,
When the parallel running vehicle switches between the manual driving mode and the automatic driving mode, the parallel running vehicle is prohibited from cutting in to the group of vehicles traveling in a convoy.

The driving assistance system of the present invention prohibits a parallel vehicle from cutting in to the platoon of vehicles when the parallel vehicle switches between driving in manual driving mode and driving in autonomous driving mode. This prevents the behavior of the parallel vehicle from becoming unstable due to cutting in when switching between driving in manual driving mode and driving in autonomous driving mode. As a result, a vehicle traveling parallel to a platoon of vehicles consisting of multiple vehicles traveling in platoon can smoothly cut in to the platoon of vehicles.

1 is a diagram showing an outline of the configuration of a vehicle 20 equipped with a driving assistance system according to an embodiment of the present invention. 10 is a flowchart showing an example of an interrupt permission/prohibition setting routine executed by an ECU 230 of a vehicle 20. 10 is a timing chart illustrating an example of time-dependent changes in the driving mode, the state of the blinker 240, the automatic driving permission condition, and whether or not to allow interruption.

Next, we will explain how to implement the present invention using examples.

Figure 1 is a diagram showing the general configuration of a vehicle 20 equipped with a driving assistance system according to one embodiment of the present invention. The vehicle 20 includes a drive unit 200, a navigation device 210, an inter-vehicle communication device 220, and an electronic control unit (hereinafter referred to as "ECU") 230. In addition to these, the vehicle 20 also includes a braking device, such as a brake, that applies braking force, a steering device, and the like, which are not shown.

The drive unit 200 is equipped with a power source and a transmission that output power for driving, and outputs power to a drive shaft connected to the axle (axle and drive shaft not shown).

The navigation device 210 sets a planned driving route from the current location of the vehicle (vehicle 20) to the destination based on stored map information, the vehicle's current location from the GPS antenna, and the destination set by the user, and displays the set planned driving route on a display (not shown) to provide route guidance.

The vehicle-to-vehicle communication device 220 performs wireless communication with vehicles surrounding vehicle 20.

Although not shown, the ECU 230 is configured as a microprocessor centered around a CPU, and in addition to the CPU, it is equipped with a ROM for storing processing programs, a RAM for temporarily storing data, and input/output ports.

Signals from various sensors required to control the drive unit 200, braking system, steering system, and four turn signals 240 attached to the front, rear, left, and right sides of the vehicle are input to the ECU 230 via an input port. Examples of signals input to the ECU 230 include vehicle speed V from a vehicle speed sensor that detects the vehicle speed of the vehicle 20, information about the vehicle 20 and its surroundings from the surroundings recognition device 250 (e.g., inter-vehicle distances D1 and D2 between the vehicle 20 and other vehicles ahead and behind the vehicle 20, the vehicle 20's position on the lane, and images of the vehicle 20's surroundings), a hold signal Sh from a steering wheel hold sensor 260 that is built into a steering wheel (not shown) that forms part of the steering device and detects whether the driver is holding the steering wheel, and an autonomous driving instruction signal Sareq from an autonomous driving instruction switch 270. The surroundings recognition device 250 is composed of a camera, millimeter-wave radar, quasi-millimeter-wave radar, infrared laser radar, sonar, etc. The ECU 230 exchanges data with surrounding vehicles via wireless communication via the vehicle-to-vehicle communication device 220.

The ECU 230 outputs control signals necessary to control the drive unit 200, braking system, steering system, and four turn signals 240 attached to the front, rear, left and right sides of the vehicle body via an output port.

The vehicle 20 configured in this manner operates by switching between an automatic driving mode, in which the vehicle 20 is driven without driver operation, and a manual driving mode, in which the vehicle 20 is driven by driver operation.

In autonomous driving mode, the ECU 230 sets the target vehicle speed V* based on the planned driving route from the navigation device 210, the vehicle's current location, map information (e.g., legal speed limits), and the inter-vehicle distances D1, D2 between the vehicle and other vehicles in front and behind the vehicle from the surrounding recognition device 250 (if other vehicles are present around the vehicle), sets the target torque Td* so that the vehicle speed V becomes the target vehicle speed V*, and controls the drive device 200 and steering device (not shown) to drive the vehicle along the planned driving route at the target torque Td*.

When the autonomous driving permission conditions are no longer met while driving in autonomous driving mode, the first handover is initiated. Examples of autonomous driving permission conditions include the autonomous driving instruction switch 270 being on and the surroundings recognition device 250 being normal. In the first handover, while driving without driver operation, a message is displayed on a monitor (not shown) near the driver's seat indicating that driving control will be handed over to the driver, and a first transition process is executed to wait for a hold signal Sh to be input from the steering wheel holding sensor 260, i.e., for the driver to hold the steering wheel. Then, when the hold signal Sh from the steering wheel holding sensor 260 detects that the driver is holding the steering wheel, the vehicle transitions to driving in manual driving mode. This process switches the driving mode from autonomous driving mode to manual driving mode.

In manual driving mode, the ECU 230 sets the target torque Td* based on the accelerator pedal position and the vehicle speed V, and controls the drive unit 200 to travel at the target torque Td*.

When the autonomous driving permission conditions are met while driving in manual driving mode, a second handover is initiated. During the second handover, a second transition process is executed in which various information required for driving in autonomous driving mode, such as input of map information (e.g., legal speed limits), is input while driving under the driver's control. Then, when the second transition process is completed, the vehicle transitions to driving in autonomous driving mode. This process switches the driving mode from manual driving mode to autonomous driving mode.

Next, we will explain the operation of vehicle 20, particularly the operation when setting whether or not to allow a vehicle to cut into a group of vehicles (platooning vehicle group) Gv traveling in a convoy. First, we will explain the configuration of the convoying vehicle group Gv, and then we will explain how to set whether or not to allow a vehicle to cut into a convoying vehicle group Gv.

The platooning vehicle group Gv is made up of multiple vehicles 30. Each vehicle 30 is equipped with a drive unit, navigation unit, vehicle-to-vehicle communication unit, surrounding recognition unit, ECU, braking unit, steering unit, etc. The drive unit, navigation unit, vehicle-to-vehicle communication unit, surrounding recognition unit, ECU, braking unit, and steering unit of vehicle 30 have the same configuration as the drive unit 200, navigation unit 210, vehicle-to-vehicle communication unit 220, ECU 230, braking unit, and steering unit of vehicle 20.

Each vehicle 30 drives in the autonomous driving mode described above using its ECU. The ECU of the lead vehicle 30a among the multiple vehicles 30 sets a target inter-vehicle distance D* in the platoon based on the planned driving route from the vehicle's navigation device, the vehicle's current location, map information (e.g., legal speed limit), and information about the vehicle's surroundings from the surroundings recognition device, and transmits the target inter-vehicle distance D* to a subordinate vehicle 30b among the multiple vehicles 30 that is subordinate to the lead vehicle 30a via its vehicle-to-vehicle communication device. Having received the target inter-vehicle distance D*, the subordinate vehicle 30b executes platoon driving control, controlling the drive unit 200 and steering device (not shown) so that the inter-vehicle distance with the vehicle 30 ahead becomes the target inter-vehicle distance D*. When vehicle 30 detects a request to cut in to the platooning vehicle group Gv from a vehicle traveling parallel to it (such as the illumination of blinker 240 or receipt of a cut-in request via vehicle-to-vehicle communication), it increases the distance between itself and the preceding vehicle 30 to allow the parallel vehicle to cut in, and becomes the new lead vehicle 30an, traveling in platoon with the following vehicle 30. The configuration of the platooning vehicle group Gv has been described above.

Next, we will explain how to set whether or not to allow a vehicle to cut into the platooning vehicle group Gv. Figure 2 is a flowchart showing an example of an interruption permission/denial setting routine executed by the ECU 230 of the vehicle 20. This routine is executed repeatedly when an interruption request is made. Examples of interruption requests include when the turn signal 240 on the platooning vehicle group Gv is manually turned on while driving in manual driving mode, or when the surrounding recognition device 250 detects an obstacle ahead while driving in autonomous driving mode.

When the interrupt permission setting routine is executed, the ECU 230 of the vehicle 20 determines whether the vehicle is in the process of switching between autonomous driving mode and manual driving mode, i.e., whether the vehicle is in the first or second handover period (step S100). If the driving mode is not being switched, interruption is permitted (step S110). If the driving mode is being switched, interruption is prohibited (step S120), and the routine ends. When switching driving modes, the behavior of the vehicle 20 is likely to become unstable due to switching between autonomous steering and manual steering, etc. If the vehicle 20 attempts to interrupt the platooning vehicle group Gv while its behavior is unstable, the behavior of the vehicle 20 may become even more unstable, preventing smooth interruption. In this embodiment, by prohibiting interruption when the driving mode is being switched and allowing interruption only after the driving mode has completely switched, the behavior of the vehicle 20 can be stabilized, allowing the vehicle 20 to smoothly interrupt the platooning vehicle group Gv.

Figure 3 is a timing chart illustrating an example of the time variations in the driving mode, the state of the turn signal 240, the autonomous driving permission conditions, and whether or not to allow cutting in. When the turn signal 240 on the side of the platooning vehicle group Gv is illuminated while the vehicle 20 is traveling parallel to the platooning vehicle group Gv in autonomous driving mode, the ECU 230 of the vehicle 20 executes the cut-in denial setting routine illustrated in Figure 2 (time t0), assuming that a cut-in request to the platooning vehicle group Gv has been made. At this time, the driving mode is not being switched, so cutting in is permitted. Subsequently, when the autonomous driving permission conditions are no longer met (time t1), the first handover is initiated and cutting in is prohibited. Then, when the first handover is completed and the vehicle transitions to driving in manual driving mode, cutting in is permitted. In this way, cutting in is permitted only after switching to driving in manual driving mode, allowing the vehicle 20 to smoothly cut into the platooning vehicle group Gv. Because cutting in is permitted only after switching to driving in manual driving mode, it is possible to ensure that cutting in is performed by the driver's driving operation. Furthermore, because the vehicle 20 is permitted to cut in after switching from manual driving mode to autonomous driving mode and then cutting in occurs, it is possible for the vehicle 20 to cut in smoothly to the platooning vehicle group Gv. Also, because the vehicle 20 is permitted to cut in after switching to autonomous driving mode, it is possible to ensure that the cutting in occurs without relying on the driver's driving operation.

With the vehicle 20 equipped with the driving assistance system of the embodiment described above, when switching between driving in manual driving mode and driving in autonomous driving mode, the vehicle 20 is prohibited from cutting into the platooning vehicle group Gv, allowing the vehicle 20 to smoothly cut into the platooning vehicle group Gv.

In the driving assistance system of the embodiment, the ECU 230 of the vehicle 20 executes the cut-in permission determination routine illustrated in Figure 2. However, instead of or in addition to the ECU 230 of the vehicle 20, the ECU of the vehicle 30 that detects the cut-in of the vehicle 20 in the platooning vehicle group Gv may execute the cut-in permission determination routine illustrated in Figure 2. In this case, the vehicle 20 transmits driving mode information to the vehicle 30 that detected the cut-in of the vehicle 20 in the platooning vehicle group Gv via vehicle-to-vehicle communication, and the vehicle 30 that detected the cut-in of the vehicle 20 in the platooning vehicle group Gv executes the process of step S100 based on the received driving mode information of the vehicle 30. Furthermore, in addition to the ECU 230 of the vehicle 20, the ECU of the vehicle 30 that detects the intrusion of the vehicle 20 into the platooning vehicle group Gv may execute the intrusion permission determination routine illustrated in FIG. 2, and when the intrusion is permitted by both the ECU 230 of the vehicle 20 and the ECU of the vehicle 30, the intrusion of the vehicle 20 into the platooning vehicle group Gv may be permitted.

The following explains the correspondence between the main elements of the embodiment and the main elements of the invention described in the "Means for Solving the Problem" section. In the embodiment, the ECU 230 corresponds to the "cruising assistance system."

The correspondence between the main elements of the Examples and the main elements of the invention described in the "Means for Solving the Problem" section does not limit the elements of the invention described in the "Means for Solving the Problem" section, as the Examples are examples used to specifically explain the form for implementing the invention described in the "Means for Solving the Problem" section. In other words, the interpretation of the invention described in the "Means for Solving the Problem" section should be based on the description in that section, and the Examples are merely specific examples of the invention described in the "Means for Solving the Problem" section.

The above describes the form for carrying out the present invention using examples, but the present invention is not limited to these examples in any way, and it goes without saying that the present invention can be embodied in various forms without departing from the spirit of the present invention.

This invention can be used in industries such as the manufacturing of driving assistance systems.

20, 30 Vehicle, 200 Drive unit, 210 Navigation device, 220 Vehicle-to-vehicle communication device, 230 Electronic control unit (ECU), 240 Turn signal, 250 Surrounding recognition device, 260 Steering wheel holding sensor, 270 Automatic driving instruction switch.

Claims (1)

A driving assistance system that supports the driving of a vehicle that travels alongside a platoon of vehicles that are traveling in a platoon and is capable of switching between driving in a manual driving mode operated by a driver and driving in an automatic driving mode not operated by the driver,
When the parallel traveling vehicle switches between traveling in the manual driving mode and traveling in the automatic driving mode, the parallel traveling vehicle is prohibited from cutting in to the group of vehicles traveling in the platoon.