Vehicle driving assistance system

Abstract

The present invention provides a vehicle driving assistance system that can suppress discomfort to the vehicle operator when the vehicle is traveling downhill while follow-me driving control is being performed. [Solution] The vehicle driving support device 10 autonomously controls the acceleration and deceleration of its own vehicle so that the distance between its own vehicle 100 and the preceding vehicle 200 is maintained at a target distance, thereby performing follow-the-preceding driving control. If there is a downhill slope on the road that the vehicle is scheduled to travel on while the vehicle driving support device is performing follow-the-preceding driving control, the vehicle driving support device increases the target distance when the distance between its own vehicle and the downhill slope shortens to a predetermined distance.

Description

Technical Field

[0001] The present invention relates to a vehicle driving support device.

Background Art

[0002] There is known a vehicle driving support device that executes follow-up driving control to make a host vehicle follow a preceding vehicle by autonomously controlling acceleration and deceleration of the host vehicle so that the inter-vehicle distance between the host vehicle and the preceding vehicle is maintained at a target inter-vehicle distance. Also, there is known a vehicle driving support device that increases the target inter-vehicle distance when the host vehicle stops on a downhill during the execution of follow-up driving control (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] By the way, when the host vehicle enters a downhill during the execution of follow-up driving control, the inter-vehicle distance tends to become short, and the necessity to brake the host vehicle increases. And if the host vehicle is continuously braked while traveling on a downhill, it may give discomfort to the driver of the host vehicle.

[0005] An object of the present invention is to provide a vehicle driving support device capable of suppressing giving discomfort to an operator of the host vehicle when the host vehicle is traveling on a downhill during the execution of follow-up driving control.

[0006] The vehicle driving support system according to the present invention includes a control device that performs follow-driving control, which causes the vehicle to follow the preceding vehicle by autonomously controlling the acceleration and deceleration of the vehicle so that the distance between the vehicle and the preceding vehicle is maintained at a target distance. The control device is configured to increase the target distance when a downhill slope exists on the road on which the vehicle is scheduled to travel during the execution of the follow-driving control, and the distance between the vehicle and the downhill slope shortens to a predetermined distance.

[0007] According to the present invention, when the vehicle enters a downhill slope, the distance between vehicles increases. Therefore, it becomes easier to maintain a sufficient distance while the vehicle is traveling downhill, and it also reduces the anxiety felt by the driver of the vehicle when approaching the vehicle in front. Furthermore, it is possible to suppress the vehicle from being continuously braked while traveling downhill. Consequently, it is possible to suppress causing discomfort to the driver of the vehicle.

[0008] Furthermore, in the vehicle driving support device according to the present invention, the control device may be configured to return the target distance between vehicles to its original target distance when the vehicle reaches the starting point of the downhill slope after the target distance between vehicles has been increased.

[0009] According to the present invention, when the vehicle enters a downhill slope, the target distance between vehicles is reduced. Therefore, it is possible to more reliably suppress the vehicle from being continuously braked while traveling downhill.

[0010] Furthermore, in the vehicle driving support device according to the present invention, the vehicle may be equipped with a motor generator and a battery. In this case, the control device may be configured to perform regenerative control, which operates the motor generator using the vehicle's driving energy to generate electricity while the vehicle is traveling downhill, and stores the generated electricity in the battery.

[0011] According to the present invention, the battery can be charged while the vehicle is traveling downhill.

[0012] The components of the present invention are not limited to the embodiments described below with reference to the drawings. Other objects, features, and incidental advantages of the present invention will be readily apparent from the description of the embodiments. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a diagram showing a vehicle driving assistance device according to an embodiment of the present invention. [Figure 2] Figure 2 shows the vehicle in front. [Figure 3] Figure 3 is a flowchart showing the routine executed by a vehicle driving assistance device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0014] Hereinafter, a vehicle driving support device according to an embodiment of the present invention will be described with reference to the drawings. Figure 1 shows a vehicle driving support device 10 according to an embodiment of the present invention. The vehicle driving support device 10 is mounted on the vehicle 100. Hereinafter, the vehicle driving support device 10 will be described using the case where the operator of the vehicle 100 is the driver of the vehicle 100 (i.e., a person who is in the vehicle 100 and drives the vehicle 100) as an example. However, the operator of the vehicle 100 may also be a remote operator of the vehicle 100 (i.e., a person who does not ride in the vehicle 100 and drives the vehicle 100 remotely).

[0015] As shown in Figure 1, the vehicle driving assistance system 10 is equipped with an ECU (Electronic Control Unit) 90 as a control device. The ECU 90 mainly consists of a microcomputer. The microcomputer includes a CPU, a computer-readable storage medium, and an interface, etc. The storage medium is ROM, RAM, and non-volatile memory, etc. The CPU realizes various functions by executing instructions, programs, or routines stored in the storage medium. In particular, in this example, the vehicle driving assistance system 10 stores programs that realize the various controls that the vehicle driving assistance system 10 performs in the storage medium.

[0016] In this example, the vehicle driving assistance system 10 is equipped with only one ECU 90, but it may also be equipped with multiple ECUs, and each ECU may be responsible for performing the functions of the vehicle driving assistance system 10 described below.

[0017] Furthermore, the vehicle driving assistance device 10 may be configured to update the program stored in the storage medium via wireless communication with an external device (for example, via the Internet).

[0018] Furthermore, the vehicle driving assistance system 10 is applicable to vehicles driven by manual operation by an operator, vehicles driven by automated driving, and vehicles driven by both manual and automated driving.

[0019] As shown in Figure 1, the vehicle 100 is equipped with a drive unit 20, an inverter 31, a battery 32, a braking unit 40, and a surrounding information detection device 50.

[0020] The drive device 20 is a device that generates a driving force applied to the host vehicle 100 (particularly, the drive wheels of the host vehicle 100). In this example, the drive device 20 includes an internal combustion engine 21 and a motor generator 22. The internal combustion engine 21 is electrically connected to the ECU 90. Also, the motor generator 22 is electrically connected to the inverter 31. The inverter 31 is electrically connected to the ECU 90. Further, the inverter 31 is electrically connected to the battery 32. The vehicle driving support device 10 can control the driving force applied to the host vehicle 100 by controlling the operations of the internal combustion engine 21 and the inverter 31. Note that the motor generator 22 is operated by the electric power supplied from the battery 32 via the inverter 31.

[0021] The braking device 40 is a device that applies a braking force to the host vehicle 100 (particularly, the wheels of the host vehicle 100). The braking device 40 is, for example, a hydraulic braking device. The braking device 40 is electrically connected to the ECU 90. The vehicle driving support device 10 can control the braking force applied to the host vehicle 100 by controlling the operation of the braking device 40.

[0022] The peripheral information detection device 50 is a device for detecting information around the host vehicle 100. In this example, the peripheral information detection device 50 includes a plurality of electromagnetic wave sensors 51 and a plurality of image sensors 52. The electromagnetic wave sensors 51 and the image sensors 52 are electrically connected to the ECU 90. The electromagnetic wave sensor 51 is, for example, a radar sensor such as a millimeter-wave radar. The vehicle driving support device 10 acquires target information IO related to a target existing around the host vehicle 100 by the electromagnetic wave sensor 51 as peripheral information IS. Also, the image sensor 52 is, for example, a camera sensor. The vehicle driving support device 10 acquires image information IC regarding the periphery of the host vehicle 100 by the image sensor 52 as peripheral information IS.

[0023] Next, the operation of the vehicle driving support device 10 will be described.

[0024] The vehicle driving support device 10 is configured to be able to execute follow - up driving control. The follow - up driving control is a control for causing the host vehicle 100 to follow and travel behind the preceding vehicle 200 by autonomously controlling the acceleration and deceleration of the host vehicle 100 so that the inter - vehicle distance D is maintained at the target inter - vehicle distance Dtgt.

[0025] As shown in FIG. 2, the inter - vehicle distance D is the distance between the host vehicle 100 and the preceding vehicle 200. The preceding vehicle 200 is another vehicle that travels on the host vehicle lane LN in front of the host vehicle 100 and exists within a predetermined distance from the host vehicle 100. The vehicle driving support device 10 detects the preceding vehicle 200 by a known method based on the surrounding information IS. Also, the vehicle driving support device 10 acquires the inter - vehicle distance D by a known method based on the surrounding information IS.

[0026] Furthermore, the vehicle driving support device 10 is configured to execute the routine shown in FIG. 3 at a predetermined time interval. Therefore, at a predetermined timing, the vehicle driving support device 10 starts processing from step S300 of the routine shown in FIG. 3. Then, the vehicle driving support device 10 advances the processing to step S305 and determines whether or not follow - up driving control is being executed.

[0027] When the vehicle driving support device 10 determines “Yes” in step S305, the processing advances to step S310, and it is determined whether or not the downhill condition C1 is satisfied. The downhill condition C1 is satisfied when there is a downhill on the planned travel road and the downhill start distance Dslp becomes shorter than the predetermined distance Dth. The planned travel road is the road that the host vehicle 100 is planned to travel on in the future. Also, the downhill start distance Dslp is the distance between the start point of the downhill existing on the planned travel road and the host vehicle 100.

[0028] Incidentally, the downhill condition C1 continues to be satisfied after the downhill start distance Dslp becomes shorter than the predetermined distance Dth, while there is a downhill on the planned travel road and the downhill start distance Dslp is greater than zero. And the downhill condition C1 ceases to be satisfied when the downhill start distance Dslp becomes zero. That is, the downhill condition C1 ceases to be satisfied when the host vehicle 100 reaches the start point of the downhill.

[0029] In this example, the vehicle driving assistance device 10 is configured to store driving route information. The driving route information is information about routes that the vehicle 100 has traveled before. The driving route information includes location information of routes that the vehicle 100 has traveled before, and location information of downhill slopes on those routes.

[0030] The vehicle driving support system 10 then determines whether the downhill condition C1 has been met based on the driving route information. More specifically, the vehicle driving support system 10 compares the route that the vehicle 100 has traveled with the driving route information to determine whether the vehicle 100 is traveling on a route that it has traveled before. If the vehicle 100 is traveling on a route that it has traveled before, the vehicle driving support system 10 determines whether there is a downhill slope on that route based on the driving route information corresponding to that route. If there is a downhill slope on that route, the vehicle driving support system 10 obtains the downhill start distance Dslp based on the location information of the downhill slope and the current position of the vehicle 100. The vehicle driving support system 10 then determines whether the downhill start distance Dslp has been shortened to a predetermined distance Dth.

[0031] Furthermore, the vehicle driving support device 10 may be configured to determine whether or not the downhill condition C1 has been met based on vehicle-to-vehicle communication information. The vehicle-to-vehicle communication information is information provided to the vehicle driving support device 10 via vehicle-to-vehicle communication from another vehicle traveling in the same lane LN ahead of the vehicle 100.

[0032] Alternatively, the vehicle driving support device 10 may be configured to determine whether or not the downhill condition C1 is met based on the image information IC, if the image sensor 52 can capture images of the area in front of the vehicle 100 up to a relatively long distance.

[0033] Alternatively, the vehicle driving support device 10 may be configured to determine whether or not downhill condition C1 is met based on information transmitted from an information provision device installed on the side of the road.

[0034] If the vehicle driving support system 10 determines "Yes" in step S310, it proceeds to step S315 and increases the target inter-vehicle distance Dtgt by a predetermined value ΔD. Next, the vehicle driving support system 10 proceeds to step S395 and terminates the processing of this routine. In this way, the vehicle driving support system 10 is configured to increase the target inter-vehicle distance Dtgt when the downhill start distance Dslp becomes shorter to a predetermined distance Dth, if there is a downhill slope on the road that the vehicle 100 is scheduled to travel on during the execution of follow-up driving control. As a result, the inter-vehicle distance D becomes larger.

[0035] On the other hand, if the vehicle driving support system 10 determines "No" in step S310, it proceeds to step S320. When the vehicle driving support system 10 proceeds to step S320, if the target inter-vehicle distance Dtgt has been increased by a predetermined value ΔD, it decreases the target inter-vehicle distance Dtgt by a predetermined value ΔD. That is, the vehicle driving support system 10 returns the target inter-vehicle distance Dtgt to its original value before it was increased. Next, the vehicle driving support system 10 proceeds to step S395 and terminates the processing of this routine.

[0036] Next, the vehicle driving support system 10 proceeds to step S325 and determines whether or not the regenerative condition C2 is met. The regenerative condition C2 is met when the vehicle 100 is traveling downhill.

[0037] If the vehicle driving support system 10 determines "Yes" in step S325, it proceeds to step S330 and executes regenerative control. Next, the vehicle driving support system 10 proceeds to step S395 and terminates the processing of this routine. As a result, regenerative control is executed while the vehicle 100 is traveling downhill.

[0038] Regenerative control is a control system that uses the driving energy of the vehicle 100 to rotate the motor generator 22 and generate electricity, and stores the generated electricity in the battery 32. The vehicle driving support device 10 performs regenerative control by controlling the operation of the inverter 31.

[0039] Furthermore, if the vehicle driving assistance device 10 determines "No" in step S305 or step S325, it proceeds directly to step S395 and terminates the processing of this routine.

[0040] The above describes the operation of the vehicle driving assistance system 10. According to the vehicle driving assistance system 10, when the vehicle 100 enters a downhill slope, the distance D between vehicles increases. Therefore, it becomes easier to maintain a sufficient distance D while the vehicle 100 is traveling downhill, and this also reduces the anxiety felt by the driver of the vehicle 100 as it approaches the preceding vehicle 200. In addition, it is possible to suppress the continuous braking of the vehicle 100 while it is traveling downhill. Therefore, it is possible to suppress causing discomfort to the driver of the vehicle 100.

[0041] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be adopted within the scope of the present invention. [Explanation of Symbols]

[0042] 10...Vehicle driving assistance system, 22...Motor generator, 32...Battery, 51...Electromagnetic wave sensor, 52...Image sensor, 90...ECU, 100...Own vehicle, 200...Preceding vehicle

Claims

1. A vehicle driving assistance system equipped with a control device that performs follow-driving control, which causes the vehicle to follow the preceding vehicle by autonomously controlling the acceleration and deceleration of the vehicle so that the distance between the vehicle and the preceding vehicle is maintained at a target distance, The control device is configured such that, during the execution of the follow-me driving control, if there is a downhill slope on the road that the vehicle is scheduled to travel on, the distance between the vehicle and the downhill slope decreases to a predetermined distance, and the target distance between vehicles is increased. Vehicle driving assistance system.

2. In the vehicle driving support device according to claim 1, The control device is configured to return the target distance between vehicles to its original value once the vehicle has increased the target distance between vehicles and reached the starting point of the downhill slope. Vehicle driving assistance system.

3. In the vehicle driving support device according to claim 1 or claim 2, The aforementioned vehicle is equipped with a motor generator and a battery, The control device is configured to perform regenerative control, which, while the vehicle is traveling down the slope, operates the motor generator using the vehicle's driving energy to generate electricity and stores the generated electricity in the battery. Vehicle driving assistance system.

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