Vehicle driving control system

Abstract

The present invention provides a vehicle driving control system that can automatically switch driving modes without causing any discomfort to the driver. [Solution] When a driving mode with modified stability control, which results in a different level of vehicle stability from the normal driving mode, is automatically determined as the automatically determined driving mode (steps S1, 6, 3), and when the driver selects a driving mode with modified stability control as the requested driving mode using the selection switch 9 (steps S1, 2, 3), in addition to displaying the driving mode, the driver is notified that the vehicle's behavior will change (step S5).

Description

Technical Field

[0005] ,

[0003]

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

Background Art

[0002] As a vehicle driving control device, for example, Patent Document 1 discloses a technique for automatically determining a driving mode suitable for the road surface condition from preset driving modes based on an image of the road surface captured by a camera and driving - controlling the vehicle based on the driving mode.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the driving control device of Patent Document 1 may give a sense of discomfort to the driver when the driving mode is switched. For example, in a driving mode assuming driving on a muddy road or the like, the control amounts for ensuring the stability of the vehicle, such as stability control and traction control, are different from those in other normal driving modes. Therefore, the driving characteristics of the vehicle are different between the two driving modes. Hereinafter, such a driving mode is referred to as a driving mode with stability function control change, and other driving modes are referred to as normal driving modes. When switching from a normal driving mode to a driving mode with stability function control change, the driver feels a sense of discomfort because the behavior of the vehicle suddenly changes. Since the average driver has few opportunities to encounter a muddy road or the like, the unfamiliarity with the behavior of the driving mode with stability function control change also contributes to strengthening the sense of discomfort.

[0005] This invention was made to solve these problems, and its objective is to provide a vehicle driving control device that can automatically switch driving modes without causing discomfort to the driver. [Means for solving the problem]

[0006] To achieve the above objective, the vehicle driving control device of the present invention is a vehicle driving control device that, based on the road surface condition determined by the road surface condition determination unit, determines a driving mode suitable for the road surface condition from among a plurality of pre-set driving modes using a driving mode switching unit, and controls the vehicle's driving by switching to the determined driving mode, characterized in that when the driving mode switching unit determines a specific driving mode as the driving mode in which the amount of control required to guarantee the vehicle's driving stability differs from that of other driving modes, it notifies the driver in advance of information regarding the specific driving mode.

[0007] Therefore, while a specific driving mode requires a different amount of control to ensure the vehicle's driving stability compared to other driving modes, the driver is aware of the change in vehicle behavior that occurs when switching driving modes, thus preventing any sense of unease caused by the change in vehicle behavior. In another embodiment, when the driving mode switching unit determines the specific driving mode, it may request permission from the driver to switch to the specific driving mode, switch to the specific driving mode when the driver grants permission, or switch to a driving mode other than the specific driving mode when the driver does not grant permission.

[0008] Therefore, if switching to a specific driving mode is permitted, the driver will be more strongly aware that the operation to grant permission will result in a change in the driving mode and, consequently, a change in the vehicle's behavior. Conversely, if switching to a specific driving mode is not permitted, the vehicle will switch to a driving mode other than the specific driving mode, resulting in only a slight change in the vehicle's behavior before and after the driving mode switch. In other embodiments, a driving mode other than the specified driving mode may be pre-set as the driving mode that is most suitable for the road surface conditions, excluding the specified driving mode.

[0009] Therefore, the vehicle's driving performance is maintained at its best because it switches to the driving mode that is most suitable for the road surface conditions, excluding specific driving modes. In other embodiments, the specific driving mode may be a driving mode in which the control amounts of the control systems, including stability control and traction control that ensure the driving stability of the vehicle by brake control, are set to be more relaxed than those of the other driving modes.

[0010] Therefore, in specific driving modes, the amount of control, including stability control and traction control that ensure the vehicle's driving stability through brake control, is relaxed compared to other driving modes. As a result, changes in the vehicle's behavior are more likely to occur when switching modes, but this situation can be recognized by the driver. [Effects of the Invention]

[0011] According to the vehicle driving control device of the present invention, the driving mode can be automatically switched without causing any discomfort to the driver. [Brief explanation of the drawing]

[0012] [Figure 1] This is a system configuration diagram of the vehicle's driving control device according to the embodiment. [Figure 2] This is a flowchart of the driving mode switching routine executed by the driving mode switching ECU. [Modes for carrying out the invention]

[0013] The following describes one embodiment of a vehicle driving control device embodying the present invention. As shown in Figure 1, the driving control device 1 consists of a driving mode switching ECU 2 (driving mode switching unit), a display ECU 3, a road surface condition determination ECU 4 (road surface condition determination unit), and other ECUs 5 connected to each other. The display ECU 3 is connected to a touch-panel display 6 and a microphone 7. The display ECU 3 informs the driver of various information via the display, and also receives input from the driver via touch operation on the display 6 and voice commands via the microphone 7, and outputs this information to the driving mode switching ECU 2.

[0014] Camera 8 is connected to the road surface condition determination ECU4, and the road surface image in front of the vehicle captured by Camera 8 is input to the road surface condition determination ECU4. The road surface condition determination ECU4 analyzes the input road surface image and determines the condition of the road surface on which the vehicle is driving, such as paved road, unpaved road, snow-covered road, muddy road, or sandy ground, and outputs the result to the driving mode switching ECU2. Other ECUs 5 include various ECUs such as the power steering ECU, and the control information from each ECU is input to the driving mode switching ECU 2.

[0015] The driving mode switching ECU 2 performs the function of switching the vehicle's driving mode, and is connected to a selection switch 9 to which the driver selects the driving mode. In this embodiment, the driving modes are pre-set as follows: Tarmac mode suitable for driving on paved roads, Gravel mode suitable for driving on unpaved roads, Snow mode suitable for driving on snowy roads, Mud mode suitable for driving on muddy roads, and Sand mode suitable for driving on sandy ground. The selection switch 9 is provided with switching positions corresponding to each of these driving modes, as well as a switching position corresponding to Auto mode, which automatically selects one of the driving modes, allowing the driver to select any mode. In the following description, the driving mode selected by the selection switch 9 will be referred to as the requested driving mode, the automatically selected driving mode will be referred to as the automatically determined driving mode, and the driving mode that is actually applied to the vehicle's driving control will be referred to as the controlled driving mode. Alternatively, the desired mode may be selected by touch operation on the display 6 instead of using the selection switch 9.

[0016] The driving mode switching ECU2 switches the control driving mode to the selected requested driving mode when one of the following modes is selected as the requested driving mode by the selection switch 9: Tarmac mode, Gravel mode, Snow mode, Mud mode, or Sand mode. Furthermore, if the driver selects Auto mode, the road surface condition determination ECU4 determines the optimal driving mode for driving on that road surface based on the road surface condition and control information input from other ECUs 5, and switches the control driving mode to the determined automatic driving mode. Based on the switched control driving mode, vehicle driving control, such as engine control, gear shift control, steering control, brake control, and suspension control, is then executed.

[0017] On the other hand, driving modes are broadly divided into normal driving modes and driving modes with modified stability control (specific driving modes). In driving modes with modified stability control, the control amounts for stability control and traction control, which are used to ensure the stability of the vehicle body, are set to different values ​​than in normal driving modes. Specifically, compared to normal driving modes, stability control and traction control are relaxed in driving modes with modified stability control, and as a result, the vehicle's driving characteristics, especially driving stability, are different. An alternative driving mode is set in advance for driving modes with modified stability control. The alternative driving mode is the driving mode that is most suitable for the road surface conditions among the normal driving modes, excluding driving modes with modified stability control. In the following explanation, it will be assumed that Mud mode is set as the driving mode with modified stability control, and Tarmac mode is set as its alternative driving mode.

[0018] Next, we will explain the processes performed by the driving mode switching ECU2. Figure 2 is a flowchart showing the driving mode switching routine executed by the driving mode switching ECU2, which performs this routine at predetermined control intervals. For the sake of explanation, it is assumed that the control driving mode applied to the vehicle's driving control is displayed on display 6.

[0019] First, in step S1, it is determined whether the Auto mode is selected by the selection switch 9. When the determination is No (negative), that is, when the required driving mode is selected, the process proceeds to step S2, and the control driving mode is switched to the selected required driving mode. In the subsequent step S3, it is determined whether the switched control driving mode is a driving mode with stability function control change. When the determination is No, the process proceeds to step S4, and a command is output to the display ECU 3 to change the driving mode being displayed on the display 6 to the switched control driving mode, and then the routine ends. Therefore, the normal driving mode selected by the selection switch 9 is displayed on the display 6, and based on this display, the driver recognizes that the switching to the selected driving mode has been performed.

[0020] Also, when the determination in step S3 is Yes (positive), the process proceeds to step S5. In addition to displaying the switched control driving mode, the display ECU 3 is made to notify the vehicle behavior change (information regarding stability). Therefore, the driving mode with stability function control change selected by the selection switch 9 is displayed on the display 6, and a message or the like notifying that the vehicle behavior changes is also displayed. Based on these displays, the driver not only recognizes the switching of the driving mode but also recognizes that the vehicle behavior changes with the mode switching.

[0021] On the other hand, when the Auto mode is selected by the selection switch 9 and the determination in step S1 is Yes (positive), the process proceeds to step S6. Based on the road surface state determined by the road surface state determination ECU 4 and the control information from other ECU 5, the optimal driving mode for driving on that road surface is determined as the automatic determination driving mode. In the subsequent step S7, it is determined whether the automatic determination driving mode is a driving mode with stability function control change. When the determination is No, the process proceeds to step S8, and the control driving mode is switched to the automatic determination driving mode. Then, the process proceeds to step S3. In this case, since it is the normal driving mode, a No determination is made and the process proceeds to step S4, and the switched normal driving mode is displayed on the display 6.

[0022] Furthermore, if a driving mode with modified stability control is determined as an automatically determined driving mode based on the road surface conditions, and a "Yes" determination is made in step S7, the system proceeds to step S9, where the driver is asked for permission to switch driving modes. Specifically, the determined driving mode with modified stability control is displayed on the display 6, along with a message asking whether or not it is OK to switch to this driving mode. In addition, a warning message may be displayed stating that the vehicle's behavior will change when the driving mode is switched. The driver can then indicate permission or prohibition by touching the display 6 or by giving voice instructions via the microphone 7.

[0023] In the following step S10, it is determined whether or not switching the driving mode is permitted. If permitted, the system determines "Yes" and proceeds to step S8, where the controlled driving mode is switched to the automatic detection driving mode. After that, the system proceeds to step S3, in which case, since the driving mode has a change in the stability function control, the system determines "Yes" and proceeds to step S5, where the controlled driving mode after the switch is displayed on display 6, and a message indicating that the vehicle's behavior has changed is also displayed.

[0024] Furthermore, if switching to a driving mode with modified stability control is not permitted in step S10, step S11 reads out the alternative driving mode set for the driving mode with modified stability control, and in the following step S12, the controlled driving mode is switched to the alternative driving mode. For example, if the driving mode with modified stability control determined in step S6 is Mud mode, Tarmac mode is read out as the alternative driving mode in step S11. Since the alternative driving mode is the normal driving mode, the system then proceeds to step S3, where it determines No and moves to step S4, displaying the normal driving mode after the switch on display 6. Because the system switches from the driving mode with modified stability control to the normal driving mode, the change in the vehicle's behavior before and after the switch is minimal.

[0025] As described above, in the driving control device 1 of this embodiment, when a driving mode with modified stability control, which results in a different vehicle stability from the normal driving mode, is automatically determined as the automatically determined driving mode (steps S1, 6, 3), the driving mode is not only displayed, but the driver is also notified that the vehicle's behavior will change (step S5). Therefore, since the driver is aware that a change in vehicle behavior occurs when the driving mode is switched, it is possible to prevent any discomfort caused by the change in vehicle behavior.

[0026] Furthermore, when a driving mode with modified stability control is selected as the requested driving mode via the selection switch 9 (steps S1, S2, S3), in addition to displaying the driving mode, the driver is also notified that the vehicle's behavior will change (step S5). The requested driving mode is the driving mode selected by the driver themselves, but some drivers may not be aware that a change in the vehicle's behavior is occurring, which could cause discomfort, but this system prevents such situations from occurring.

[0027] Furthermore, if the automatic driving mode is determined to be a driving mode with modified stability control (steps S1, 6, 7), the driver is asked for permission to switch driving modes (step S9), and if permission is granted, the system switches to a driving mode with modified stability control (steps S10, 8). By granting permission to switch modes, the driver becomes more strongly aware of the change in driving mode and, consequently, the change in the vehicle's behavior, thus more effectively preventing any sense of unease caused by this change.

[0028] Furthermore, if the driver is not permitted to switch driving modes (steps S9, 10), the system switches to an alternative driving mode that is pre-set as one of the normal driving modes (steps S10, 11, 12). As a result, the change in the vehicle's behavior before and after switching driving modes is minimal, preventing the driver from feeling any discomfort. In addition, since the alternative driving mode is set to the driving mode that is best suited to the road surface conditions among the normal driving modes, good vehicle driving performance can be maintained.

[0029] This concludes the description of the embodiments, but the embodiments of the present invention are not limited to these embodiments. For example, in the above embodiments, the display 6 displays the driving mode and whether or not there is a change in the vehicle's behavior (steps S4, 5), and requests permission to switch driving modes (step S9), but in addition to this, a message may be output as voice from the speaker. Also, in the above embodiments, permission or prohibition was instructed by touch operation on the display 6 or voice instruction via microphone 7, but instead, permission or prohibition may be instructed by operation of a dedicated switch. [Explanation of Symbols]

[0030] 1. Driving control device 2. Driving mode switching ECU (driving mode switching unit) 4. Road surface condition determination ECU (Road surface condition determination unit)

Claims

1. In a vehicle driving control device that controls the vehicle's movement by switching to the determined driving mode, the driving mode switching unit determines a driving mode suitable for the road surface conditions from among a plurality of pre-set driving modes based on the road surface conditions determined by the road surface condition determination unit, When the driving mode switching unit determines a specific driving mode in which the amount of control required to ensure the vehicle's driving stability differs from that of other driving modes, it notifies the driver in advance of information regarding the specific driving mode. A vehicle driving control device characterized by the following features.

2. The driving mode switching unit, upon determining the specific driving mode, requests permission from the driver to switch to the specific driving mode, switches to the specific driving mode when the driver grants permission, and switches to a driving mode other than the specific driving mode when the driver does not grant permission. The vehicle driving control device according to feature 1.

3. Driving modes other than the aforementioned specific driving mode are pre-set as the driving mode best suited to the road surface conditions, excluding the aforementioned specific driving mode. The vehicle driving control device according to feature 2.

4. The aforementioned specific driving mode is a driving mode in which the control amounts of the control systems, including stability control and traction control that ensure the driving stability of the vehicle through brake control, are set to be more relaxed than those of the other driving modes. A vehicle driving control device according to any one of claims 1 to 3.

Images