Vehicle control device

Abstract

To enhance detection accuracy of a road surface state when a vehicle is traveled and perform adequate vehicle control which adapts to the road surface state by selecting a drive mode which is more suitable for the road surface state.SOLUTION: A vehicle control device 1 comprises: road surface state recognition units 12a, 12b which determine a road surface state of each contact area of a plurality of wheels provided on a vehicle 2, respectively on the basis of a past road surface projected image which is contained in a first road surface projected image taken by first cameras 4, 8 which image the road surface in a direction of travel of the vehicle 2 and a second road surface projected image taken by a second camera 3 which images the road surface in a direction different from the direction of travel; and a drive mode determination unit 11 which selects at least one drive mode from plural kinds of drive modes on the basis of the road surface of each of the contact areas of the plurality of wheels.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control device that determines road surface conditions and sets a drive mode. [Background technology]

[0002] In recent years, technologies have been developed that detect road surface conditions and run a vehicle in a driving mode appropriate for the detected road surface conditions. For example, Patent Document 1 discloses an image data evaluation unit that classifies road surface conditions based on image data from an on-board camera system. The method disclosed in Patent Document 1 uses a camera with a capture area facing the side of the vehicle to identify obstacles in an image caused by road surface coverings as the vehicle's tires pass over the road surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2021-517675 Summary of the Invention [Problem to be solved by the invention]

[0004] However, a camera with a capture area facing the side of the vehicle can grasp the road surface conditions near the tires, but cannot capture the road surface conditions directly below the tires. Also, because the sides of the vehicle are outside the range of headlight illumination, it is difficult to grasp the road surface conditions with high accuracy at night or in low-light environments. In other words, a system with a camera such as that described in Patent Document 1 has low detection accuracy of road surface conditions, and there is a risk that a drive mode appropriate for the road surface conditions will not be selected.

[0005] The present invention has been devised in view of the above-mentioned problems, and one of its objectives is to improve the accuracy of detecting road surface conditions while the vehicle is traveling, and to select a drive mode that is more suitable for the road surface conditions, thereby performing appropriate vehicle control suited to the road surface conditions. However, in addition to this objective, another objective of the present invention is to achieve effects that are derived from the configurations shown in the below-described embodiments of the invention, and that cannot be obtained by conventional techniques. [Means for solving the problem]

[0006] The disclosed vehicle control device can be realized as the following disclosed aspects (application examples), which solve at least part of the above-mentioned problems. Each of the aspects from aspect 2 onwards is an aspect that can be selected additionally as appropriate, and each of the aspects can be omitted. None of the aspects from aspect 2 onwards discloses an aspect or configuration that is essential to the present invention.

[0007] Aspect 1. The disclosed vehicle control device includes a road surface condition recognition unit that determines the road surface condition of each of the contact surfaces of multiple wheels mounted on the vehicle based on past road surface images included in a first road surface image captured by a first camera that captures the road surface in the direction of travel of the vehicle and a second road surface image captured by a second camera that captures the road surface in a direction different from the direction of travel, and a drive mode determination unit that selects at least one drive mode from multiple types of drive modes based on the road surface condition of each of the contact surfaces of the multiple wheels.

[0008] Aspect 2. In an aspect including Aspect 1 above, it is preferable that the road surface condition recognition unit, while the vehicle is traveling or immediately after it has stopped, determines the road surface condition of each of the contact surfaces using a first detection method that uses the past road surface image and a second detection method that uses the second road surface image.

[0009] Aspect 3. In an aspect including aspect 1 above, it is preferable that the road surface condition recognition unit determines the road surface condition of each of the contact surfaces using a second detection method that uses the second road surface image immediately after the vehicle is powered on or after a certain period of time has passed since the vehicle was stopped.

[0010] Aspect 4. In an aspect including aspect 1 above, it is preferable that the road surface condition recognition unit determines the road surface condition of each of the contact surfaces using a first detection method that uses past road surface images when the vehicle is traveling at night or in a low-light environment.

[0011] Aspect 5. In an aspect including aspect 1 above, if the vehicle has an independent front, rear, left, and right drive system, it is preferable that the drive mode determination unit selects a drive mode for each of the front, rear, left, and right wheels that corresponds to the road surface condition of the contact surfaces of each of the front, rear, left, and right wheels.

[0012] Aspect 6. In an aspect including Aspect 1 above, when the vehicle has a front and rear independent drive system and different road surface conditions are determined for the contact surfaces of the left and right wheels on the front or rear sides, it is preferable that the drive mode determination unit selects, for the left and right wheels, the drive mode with the highest priority among the drive modes corresponding to each of the determined road surface conditions.

[0013] Aspect 7. In an aspect including Aspect 1 above, when the vehicle has an all-wheel-linked drive system and different road surface conditions are determined for the contact surfaces of the front, rear, left, and right wheels, it is preferable that the drive mode determination unit selects, for the front, rear, left, and right wheels, the drive mode with the highest priority among the drive modes corresponding to each of the determined road surface conditions.

[0014] Aspect 8. In an aspect including aspect 1 above, when the drive mode determination unit determines that the road surface conditions are different for the contact surfaces of two or more wheels in the front, rear, left, and right wheels, it is preferable that the drive mode determination unit selects a drive mode that corresponds to the road surface condition of the contact surface of the wheel that bears the most load among the two or more wheels when the vehicle is running.

[0015] Aspect 9. In an aspect including the aspect 1 above, it is preferable that the drive mode determination unit selects a drive mode corresponding to the most frequently determined road surface condition among the road surface conditions of each of the contact surfaces of the plurality of wheels.

[0016] Aspect 10. In an aspect including Aspect 1 above, it is preferable that the drive mode determination unit selects a drive mode corresponding to the road surface condition of the contact surface of the drive wheel among the plurality of wheels when the vehicle is traveling straight. [Effects of the Invention]

[0017] According to the disclosed vehicle control device, the detection accuracy of road surface conditions while the vehicle is traveling is improved, and a drive mode that is more suitable for the road surface conditions is selected, thereby enabling appropriate vehicle control that suits the road surface conditions. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a block diagram of a vehicle control device according to an embodiment. [Figure 2] 2 is a diagram showing an example of an image captured by a left camera mounted on the vehicle of FIG. 1. FIG. [Figure 3] 1 is a table showing the order in which the load acting on a tire increases in each of a plurality of types of driving conditions. [Figure 4] 2(a) and 2(b) are a diagram and a table illustrating a drive mode setting method by a drive mode determination unit in the vehicle control device of FIG. 1. [Figure 5] 2(a) and 2(b) are a diagram and a table illustrating a drive mode setting method by a drive mode determination unit in the vehicle control device of FIG. 1. [Figure 6] 2(a) and 2(b) are a diagram and a table illustrating a drive mode setting method by a drive mode determination unit in the vehicle control device of FIG. 1. [Figure 7] 2(a) and 2(b) are a diagram and a table illustrating a drive mode setting method by a drive mode determination unit in the vehicle control device of FIG. 1. [Figure 8] 4 is an example of a flowchart illustrating the above-described processing performed by the vehicle control device. DETAILED DESCRIPTION OF THE INVENTION

[0019] A vehicle control device according to an embodiment will be described with reference to the drawings. The embodiment described below is merely an example, and is not intended to exclude various modifications or application of techniques not explicitly described in the embodiment. The configurations of the present embodiment can be modified in various ways without departing from the spirit of the invention. Furthermore, the configurations can be selected or combined as needed.

[0020] The vehicle control device of the embodiment is a device applied to a vehicle equipped with multiple cameras that capture images of the outside of the vehicle (outside the vehicle). In the following description, the forward direction of the vehicle is referred to as the forward direction (front of the vehicle), and the opposite direction is referred to as the rearward direction (rear of the vehicle). The traveling direction of the vehicle is the forward direction when the vehicle is moving forward, and the rearward direction when the vehicle is moving backward. Furthermore, left and right are defined based on the state in which the vehicle is facing forward. The left and right directions are perpendicular to the front-to-rear direction of the vehicle. The direction perpendicular to both the front-to-rear direction and the left and right directions of the vehicle is defined as the up and down direction.

[0021] [1. Overall structure] A vehicle control device 1 (hereinafter simply referred to as "control device 1") according to this embodiment is applied to a vehicle 2 equipped with a side camera 3 (second camera) and a front camera 4 (first camera), as shown in FIG. 1. The vehicle 2 may be equipped with a rear camera 8 (first camera), a wheel speed sensor 5, and a steering sensor 6. The control device 1 may be mounted on the vehicle 2 as shown in FIG. 1, or may be provided external to the vehicle 2 and perform the above processing via communication with the vehicle 2.

[0022] The control device 1 realizes a function of selecting a drive mode according to the type of road surface on which the vehicle 2 is traveling. More specifically, the control device 1 has a road surface condition determination function that determines the condition (type) of the road surface (contact surface) on which each wheel (tire) is in contact with the ground based on images (camera images) captured by the side camera 3 and the front camera 4 (and the rear camera 8), and a drive mode selection function that selects a drive mode appropriate for the determined road surface condition. In the vehicle 2, the drive system and / or braking system mounted on the vehicle 2 are controlled according to the drive mode selected by the control device 1, and driving force and / or braking force are applied to the multiple tires. The vehicle 2 is equipped with, for example, four tires: a front right tire, a rear right tire, a front left tire, and a rear left tire. As the road surface condition determination function, the control device 1 determines the road surface condition of each of the contact surfaces of the four tires, i.e., the road surface conditions of the contact surfaces at four locations.

[0023] The front camera 4 is a camera (image capturing device) that captures an image of the road surface ahead of the vehicle 2, and the image capturing range includes the road surface ahead of the vehicle 2. The front camera 4 is disposed, for example, on the front end surface of the vehicle 2 and faces forward of the vehicle 2. The image of the road surface ahead of the vehicle captured by the front camera 4 is an example of a first road surface image, and is input to the past image recording unit 13 of the control device 1.

[0024] The rear camera 8 is a camera (image capturing device) that captures an image of the road surface behind the vehicle 2, and the image capturing range includes the road surface behind the vehicle 2. The rear camera 8 is disposed, for example, on the rear end surface of the vehicle 2 and faces rearward of the vehicle 2. The image of the road surface behind the vehicle captured by the rear camera 8 is an example of a first road surface image, and is input to the past image recording unit 13 of the control device 1.

[0025] The side cameras 3 are cameras (imaging devices) that capture images of the road surface in a direction different from the traveling direction of the vehicle 2. The side cameras 3 include a right camera 3R and a left camera 3L. Hereinafter, when there is no need to distinguish between the right camera 3R and the left camera 3L, they will be referred to as side cameras 3.

[0026] The right camera 3R photographs the road surface to the right of the vehicle 2. The imaging range of the right camera 3R may include the right side of the vehicle 2 in addition to the road surface to the right of the vehicle 2. The right camera 3R is, for example, disposed on the right side mirror and faces the lower right of the vehicle 2. The left camera 3L photographs the road surface to the left of the vehicle 2. The imaging range of the left camera 3L may include the left side of the vehicle 2 in addition to the road surface to the left of the vehicle 2. The left camera 3L is, for example, disposed on the left side mirror and faces the lower left of the vehicle 2.

[0027] The side camera 3 may be a fisheye camera. A fisheye camera is a camera equipped with a fisheye lens that has a wider angle of view than a standard lens (for example, a horizontal angle of about 190° and a vertical angle of about 150°), and can capture a wider range than a standard camera. In the vehicle 2, by using a fisheye camera particularly for the side camera 3, it becomes possible to capture images of the road surface around the tires of the vehicle 2.

[0028] FIG. 2 is a diagram showing an example of an image captured by the left camera 3L. In FIG. 2, the black areas indicate areas not captured by the left camera 3L. When the left camera 3L is a fisheye camera, as shown in FIG. 2, the captured image includes an area capturing the body (left side) of the vehicle 2, including the front left tire FLT and the rear left tire RLT, and an area capturing the road surface (ground) near each of the front left tire FLT and the rear left tire RLT. In other words, the side camera 3 captures an image of the road surface around the tires of the vehicle 2. The image of the road surface around the tires captured by the side camera 3 is an example of a second road surface image, and is input to the first road surface condition recognition unit 12a.

[0029] The wheel speed sensor 5 is a device that detects the rotational speed (wheel speed) of each tire of the vehicle 2 as a signal, and may also have the function of detecting the vehicle speed and acceleration of the vehicle 2. Information on the vehicle speed and acceleration based on the wheel speed detected by the wheel speed sensor 5 is input to the past video recording unit 13 and the loaded tire determination unit 14 of the control device 1, respectively.

[0030] The steering sensor 6 is a sensor attached to a steering wheel (not shown) of the vehicle 2, and detects, for example, the steering angle of the steering wheel. Information on the steering angle detected by the steering sensor 6 is input to both the past video recording unit 13 and the loaded tire determination unit 14 of the control device 1.

[0031] [2. Control device] As shown in FIG. 1, the control device 1 is provided with a drive mode determination unit 11, a first road surface condition recognition unit 12a, a second road surface condition recognition unit 12b, a past video recording unit 13, and a loaded tire determination unit 14 as functional elements.

[0032] The first road surface condition recognition unit 12a judges the road surface condition of the contact surface of each tire based on the second road surface image. The past image recording unit 13 records the first road surface image. The second road surface condition recognition unit 12b judges the road surface condition of the contact surface of each tire based on past road surface images included in the first road surface images recorded in the past image recording unit 13.

[0033] The loaded tire determination unit 14 determines which tire (hereinafter also referred to as "loaded tire") is carrying the highest load among the plurality of tires of the vehicle 2. The drive mode determination unit 11 selects at least one drive mode from among a plurality of drive modes based on the road surface conditions determined by the first road surface condition recognition unit 12a and the second road surface condition recognition unit 12b.

[0034] These functional elements may be realized by electronic circuits (hardware), may be programmed as software, or some of these functions may be provided as hardware and the other parts as software.

[0035] [2-1. First road surface condition recognition unit] As described above, the first road surface condition recognition unit 12a determines the road surface condition of the contact surface of each tire based on the second road surface image. In this embodiment, the first road surface condition recognition unit 12a determines the road surface condition of each of the contact surfaces of the four tires based on the road surface image around the tires captured by the side camera 3. More specifically, the first road surface condition recognition unit 12a determines the road surface condition of each of the contact surfaces of the front right tire and the rear right tire based on the image captured by the right camera 3R. Furthermore, the first road surface condition recognition unit 12a determines the road surface condition of each of the contact surfaces of the front left tire and the rear left tire based on the image captured by the left camera 3L.

[0036] If the side camera 3 is a fisheye camera, the second road surface image includes each tire and the road surface near each tire, as described above. The first road surface condition recognition unit 12a may recognize each tire from such second road surface image and determine the road surface condition of each tire's contact surface based on an image of an area adjacent to the area including the recognized tire. In other words, the first road surface condition recognition unit 12a may estimate the condition of the road surface adjacent to each tire (the road surface around each tire) as the road surface condition of each tire's contact surface.

[0037] In this embodiment, the first road surface condition recognition unit 12a determines whether the road surface condition is one of three types: snow (snowy road surface), dry (dry paved road), or dirt (dirt road surface). Note that various known methods may be used to determine the road surface condition based on the second road surface image. Furthermore, the first road surface condition recognition unit 12a may determine (identify) the road surface condition by combining the second road surface image with information such as weather information at the current location of the vehicle 2.

[0038] The method of determining the road surface condition of each tire's contact surface by the first road surface condition recognition unit 12a can also be described as a second detection method that uses an image of the road surface in a direction different from the traveling direction (second road surface image). The first road surface condition recognition unit 12a is an example of a road surface condition recognition unit that determines the road surface condition of each tire's contact surface based on the second road surface image. The road surface conditions of each tire's contact surface determined by the first road surface condition recognition unit 12a (the determination result of the first road surface condition recognition unit 12a) are passed to the drive mode determination unit 11.

[0039] [2-2. Past Footage Recording Section] The past video recording unit 13 records the first road surface image, and stores the first road surface image in, for example, a storage device (not shown). In this embodiment, the past video recording unit 13 stores the road surface image in front of the vehicle captured by the front camera 4 and the road surface image behind the vehicle captured by the rear camera 8 as the first road surface image. The past video recording unit 13 may store the road surface image in front of the vehicle when the vehicle 2 is moving forward, and may store the road surface image behind the vehicle when the vehicle 2 is moving backward, as the first road surface image. The past video recording unit 13 may store the first road surface image, information on acceleration and vehicle speed based on the wheel speed sensor 5, and information on steering angle based on the steering sensor 6, in association with each other.

[0040] [2-3. Second road surface condition recognition unit] The second road surface condition recognition unit 12b judges the road surface condition of the contact surface of each tire based on the first road surface image recorded in the past image recording unit 13. Here, the first road surface image recorded in the past image recording unit 13 includes an image of the road surface that will become the contact surface of each tire a predetermined time after the image is captured as the vehicle 2 moves forward or backward. The second road surface condition recognition unit 12b identifies the image of the road surface that will become the contact surface of each tire, which is included in the first road surface image recorded in the past image recording unit 13, as a past road surface image.

[0041] That is, the second road surface condition recognition unit 12b does not acquire the first road surface image in real time, but identifies a portion (past road surface image) that is estimated to be the current contact patch of each tire from the past first road surface image recorded in the past image recording unit 13. The past road surface image can be identified by various known methods using the acceleration and vehicle speed of the vehicle 2 based on the wheel speed sensor 5 and the steering angle based on the steering sensor 6. The second road surface condition recognition unit 12b may identify the past road surface image for each tire.

[0042] The second road surface condition recognition unit 12b determines the road surface condition of the contact surface of each tire based on each of the identified past road surface images. In other words, the second road surface condition recognition unit 12b determines the road surface condition of the contact surface for each tire.

[0043] In this embodiment, the second road surface condition recognition unit 12b, like the first road surface condition recognition unit 12a, determines whether the road surface condition is one of three types of road surface: snow (snowy road surface), dry (dry paved road), or dirt (dirt road surface). Note that various known methods may be used to determine the road surface condition based on past road surface images. Furthermore, the second road surface condition recognition unit 12b may determine (identify) the road surface condition by combining past road surface images with information such as weather information at the current location of the vehicle 2.

[0044] The method of determining the road surface condition of each tire's contact surface by the second road surface condition recognition unit 12b can also be described as a first detection method using past road surface images. The second road surface condition recognition unit 12b is an example of a road surface condition recognition unit that determines the road surface condition of each tire's contact surface based on past road surface images included in the second road surface images. The road surface conditions of each tire's contact surface determined by the second road surface condition recognition unit 12b (the determination result of the second road surface condition recognition unit 12b) are passed to the drive mode determination unit 11.

[0045] [2-4. Load Tire Judgment Section] As described above, the loaded tire determination unit 14 determines whether a tire is loaded. For example, when the running state of the vehicle 2 changes, the loaded tire determination unit 14 may determine that the tire on which the load increases first compared to the load before the change is the loaded tire. The loaded tire determination unit 14 may determine whether a tire is loaded based on the running state of the vehicle 2 by referring to information such as that shown in FIG. 3.

[0046] Fig. 3 is a diagram showing the order in which high loads are applied to the tires of the vehicle 2 in each of a plurality of driving states. Note that "high load" here means that the load has increased compared to the load before the driving state changed. Fig. 3 shows the order in which high loads are applied to each tire in the cases of deceleration, steady state, and acceleration in each of the driving states of turning left, turning right, and going straight.

[0047] For example, during deceleration when turning left, the front right tire is determined to be the loaded tire because a high load is applied first to the front tire. During acceleration when turning left, the rear right tire is determined to be the loaded tire because a high load is applied first to the rear tire. Conversely, during deceleration when turning right, the front left tire is determined to be the loaded tire because a high load is applied first to the front tire. During acceleration when turning right, the rear left tire is determined to be the loaded tire because a high load is applied first to the rear tire. Furthermore, during deceleration when traveling straight, the left and right front tires (the front left and right wheels) are determined to be the loaded tires because a high load is applied first to each of them, and both the front right tire and the front left tire are determined to be the loaded tires. During acceleration when traveling straight, the left and right rear tires (the rear left and right wheels) are determined to be the loaded tires because a high load is applied first to each of them, and both the rear right tire and the rear left tire are determined to be the loaded tires.

[0048] [2-5. Drive mode determination section] The drive mode determination unit 11 selects at least one drive mode from a plurality of drive modes based on the road surface conditions of each of the contact surfaces of a plurality of tires. The plurality of drive modes will be described in detail later.

[0049] In this embodiment, the road surface condition of each of the plurality of tire contact surfaces is determined individually by the first road surface condition recognition unit 12a and the second road surface condition recognition unit 12b. Therefore, the drive mode determination unit 11 makes a final determination (identification) of the road surface condition of each of the plurality of tire contact surfaces based on both the determination results of the first road surface condition recognition unit 12a and the determination results of the second road surface condition recognition unit 12b. In other words, it can be said that the drive mode determination unit 11 of this embodiment also has part of the function of a road surface condition recognition unit that determines the road surface condition of each of the plurality of tire contact surfaces based on past road surface images and the second road surface image.

[0050] For example, at night or in a low-light environment, the drive mode determination unit 11 directly adopts the determination result of the second road surface condition recognition unit 12b as the road surface condition for each tire. That is, when the vehicle 2 is traveling at night or in a low-light environment, the drive mode determination unit 11 determines the road surface condition of each contact patch using the first detection method. This is because at night or in a low-light environment, the image captured by the side camera 3 becomes unclear, and the accuracy of the determination of the road surface condition by the first road surface condition recognition unit 12a may be low.

[0051] Furthermore, the drive mode determination unit 11 adopts the determination result of the first road surface condition recognition unit 12a as the road surface condition for each tire, for example, immediately after the vehicle 2 is powered on or after a certain time (e.g., one hour) has elapsed since the vehicle 2 was stopped. That is, immediately after the vehicle 2 is powered on or after a certain time has elapsed since the vehicle 2 was stopped, the drive mode determination unit 11 determines the road surface condition of each contact patch using the second detection method. This is because, immediately after the vehicle 2 is powered on, the first road surface image before the vehicle 2 is powered on is not stored in the past image recording unit 13, and there is a risk that the second road surface condition recognition unit 12b will not be able to accurately determine the road surface condition. Furthermore, after a certain time has elapsed since the vehicle was stopped, there is a risk that the second road surface condition recognition unit 12b will not be able to accurately determine the road surface condition if the road surface condition of each tire's contact patch changes while the vehicle was stopped.

[0052] In other circumstances than those mentioned above (for example, during the day or in a non-low-illumination environment while the vehicle 2 is traveling or immediately after it has stopped), the drive mode determination unit 11 identifies the road surface condition for each tire based on both the determination result of the second road surface condition recognition unit 12b and the determination result of the first road surface condition recognition unit 12a. That is, while the vehicle 2 is traveling or immediately after it has stopped, the drive mode determination unit 11 determines the road surface condition of each contact patch using the first detection method and the second detection method.

[0053] For example, when the determination result of the second road surface condition recognizing section 12b and the determination result of the first road surface condition recognizing section 12a match each other, the drive mode determining section 11 adopts the road surface condition.

[0054] Furthermore, when the determination result of the second road surface condition recognition unit 12b and the determination result of the first road surface condition recognition unit 12a do not match, the determination result of one of them (for example, the second road surface condition recognition unit 12b) may be used preferentially. When the determination result of the second road surface condition recognition unit 12b is used preferentially, the drive mode determination unit 11 may complement the determination of the road surface condition by the second road surface condition recognition unit 12b using the road surface condition determined by the first road surface condition recognition unit 12a. In other words, the drive mode determination unit 11 complements the determination of the road surface condition using the past road surface images included in the road surface images captured by the front camera 4 or the rear camera 8 using the road surface images around the tires captured by the side camera 3.

[0055] If the determination result of the second road surface condition recognizing unit 12b and the determination result of the first road surface condition recognizing unit 12a do not match, the drive mode determining unit 11 may postpone determining the road surface condition for the time being, and may determine the road surface condition again after receiving the determination results again from each of the first road surface condition recognizing unit 12a and the second road surface condition recognizing unit 12b. This increases the reliability of the determined road surface condition.

[0056] If some of the determination results of the recognition units 12a and 12b match, that is, if the road surface conditions of the contact surfaces of some of the four tires match, the drive mode determination unit 11 may adopt the determination results of the recognition units 12a and 12b as the road surface conditions of the contact surfaces of those tires. For the road surface conditions of the remaining tire contact surfaces, the drive mode determination unit 11 may preferentially adopt the determination results of either the first road surface condition recognition unit 12a or the second road surface condition recognition unit 12b, or may postpone determining the road surface condition.

[0057] The drive mode determination unit 11 selects (sets) a drive mode for the vehicle 2 based on the road surface conditions of the contact surfaces of the plurality of tires determined as described above. When selecting the drive mode, the drive mode determination unit 11 may take into account the determination result of the loaded tire determination unit 14.

[0058] In this embodiment, if the drive mode determination unit 11 determines that the road surface condition is snow, it selects snow mode as the drive mode. If the road surface condition is dry, it selects normal mode as the drive mode. If the road surface condition is dirt, it selects gravel mode as the drive mode. In other words, in this embodiment, three types of drive modes are shown: snow mode, normal mode, and gravel mode.

[0059] When the snow mode is selected in the vehicle 2, control suitable for slippery road surfaces such as snowy roads is implemented, for example, control to suppress slippage of each tire. When the gravel mode is selected, control to provide strong traction performance and high stability on unpaved roads such as gravel roads is implemented. When the normal mode is selected, control that can be widely adapted to various road conditions and driving situations is implemented, for example, control that takes into account the balance between driving performance and fuel efficiency.

[0060] Note that each drive mode can be realized using various known methods, and a detailed description of each will be omitted. Also, the drive modes are not limited to the three types described above, and may be two types, or four or more types.

[0061] Priority may be assigned to these three drive modes when they are set. In this embodiment, snow mode is assigned a higher priority than normal mode and gravel mode, and the drive mode determination unit 11 selects snow mode with priority over normal mode and gravel mode. Note that there is no priority between normal mode and gravel mode (i.e., between dry and dirt road surface conditions).

[0062] The drive mode determination unit 11 may select (set) the drive mode in accordance with the drive mode setting rules exemplified below, for example.

[0063] Drive mode setting rule 1: If vehicle 2 is a four-wheel independent drive system, a drive mode corresponding to the road surface conditions of each tire's contact surface is selected for each tire. Note that a vehicle with independent front / rear / left / right drive system here refers to a vehicle in which driving force and / or braking force can be applied individually to each of the four tires (front / rear / left / right). An example of a vehicle in which driving force can be applied individually to each of the four tires is a vehicle equipped with an in-wheel motor.

[0064] Drive mode setting rule 2: If vehicle 2 has a front and rear independent drive system and different road surface conditions are determined for the contact surfaces of the left and right front or rear tires, the drive mode with the highest priority among the drive modes corresponding to the determined road surface conditions is selected for the left and right tires. Note that a front and rear independent drive vehicle here refers to a vehicle in which driving force and / or braking force can be applied separately to the front tires and rear tires. An example of a front and rear independent drive vehicle is a vehicle equipped with a front motor and a rear motor as drive sources.

[0065] Drive mode setting rule 3: If vehicle 2 is an all-wheel drive system and different road surface conditions are determined for each of the front, rear, left, and right tires, the drive mode with the highest priority among the drive modes corresponding to each determined road surface condition is selected for each of the front, rear, left, and right tires. The all-wheel-linked vehicle referred to here means a vehicle in which all four tires are driven by a single drive source (for example, a motor or an engine).

[0066] Drive mode setting rule 4: If different road surface conditions are determined for two or more tire contact surfaces on the front, rear, left, and right tires, the drive mode that corresponds to the road surface condition of the tire contact surface that bears the greatest load among the two or more tires while vehicle 2 is running is selected.

[0067] · Drive mode setting rule 5: Select the drive mode that corresponds to the road surface condition that is most frequently determined among the road surface conditions of multiple tire contact surfaces.

[0068] Drive mode setting rule 6: When vehicle 2 is traveling straight, a drive mode that corresponds to the road surface conditions of the contact surfaces of the drive wheels among the multiple tires is selected.

[0069] An example of how the drive mode determination unit 11 selects a drive mode in accordance with the drive mode setting rules 1 to 6 will be shown with reference to FIGS.

[0070] Figures 4(a), 5(a), 6(a), and 7(a) are diagrams each showing the road surface conditions of the contact surface of each tire of a vehicle 2. In these diagrams, multiple types of road surface conditions for the contact surface of each tire are shown as rectangles, and three vehicles 2 are shown overlapping each other in the rectangles as a top view. The three vehicles 2 in each diagram (a) are positioned so that the road surface conditions of each tire's contact surface are different, and there is no chronological relationship between these three vehicles 2. The symbols (1), (2), and (3) in the diagrams correspond to the table in (b) of each diagram.

[0071] Figures 4(b), 5(b), 6(b), and 7(b) are tables showing the road surface conditions of the contact surfaces of each tire in relation to the drive modes for each drive system for three vehicles 2 indicated by symbols (1) to (3) in Figures 4(a), 5(a), 6(a), and 7(a), respectively.

[0072] In each of Figures 4(b) and 5(b), three types of drive systems are shown: front / rear / left / right independent drive system, front / rear independent drive system, and one motor or one engine (ENG) drive system. The one motor or one engine drive system is a state in which all tires are connected. The one motor or one engine drive system can be called an all-tire connected drive system or an all-wheel connected drive system. Figure 6(b) shows only the all-tire connected drive system as a drive system. Figure 7(b) shows only the front / rear independent drive system as a drive system.

[0073] In Fig. 4(a), for example, the vehicle 2 in the state indicated by reference symbol (1) has a road surface condition of the contact areas of both the front right tire and the front left tire that is dry, and a road surface condition of the contact areas of both the rear right tire and the rear left tire that is snow. In Fig. 4(a), each of the three vehicles 2 indicated by reference symbols (1) to (3) is assumed to be traveling straight at a steady speed (constant velocity).

[0074] As shown in FIG. 4(b), for vehicle 2 in the state indicated by symbol (1), for the front, rear, left, and right independent drive system, drive mode determination unit 11 selects a drive mode for each tire depending on the road surface condition of the tire's contact surface (drive mode setting rule 1). That is, normal mode is selected as the drive mode for each of the front right tire and front left tire. Snow mode is selected as the drive mode for each of the rear right tire and rear left tire. For the front and rear independent drive system, the road surface condition of the tire's contact surface is dry, so normal mode is selected as the drive mode for the front tires. And the road surface condition of the tire's contact surface is snow, so snow mode is selected as the drive mode for the rear tires. For the one-motor or one-engine drive system, since different road surface conditions are determined for the tire's contact surface, drive mode setting rule 3 is applied, and snow mode, which has a higher priority, is selected.

[0075] In the vehicle 2 in the state indicated by the symbol (2), the road surface condition of the contact surfaces of all tires is snow. Therefore, for the front, rear, left, and right independent drive system, the drive mode determination unit 11 selects snow mode as the drive mode for each tire in accordance with drive mode setting rule 1. For the front and rear independent drive system, snow mode is selected as the drive mode for the front side and the rear side. For the one-motor or one-engine drive system, snow mode is selected.

[0076] In addition, in the vehicle 2 in the state indicated by the symbol (3), the road surface condition of the contact surfaces of both the front right tire and the front left tire is snow, and the road surface condition of the contact surfaces of the rear right tire and the rear left tire is dry. For the front-rear, left-right, and right-left independent drive system, the drive mode determination unit 11 selects snow mode as the drive mode for each of the front right tire and the front left tire, and normal mode as the drive mode for each of the rear right tire and the rear left tire, in accordance with drive mode setting rule 1. For the front-rear independent drive system, it selects snow mode as the drive mode for the front side and normal mode as the drive mode for the rear side. For the one-motor or one-engine drive system, it selects the snow mode with the highest priority in accordance with drive mode setting rule 3.

[0077] In Fig. 5(a), for example, the vehicle 2 in the state indicated by reference symbol (1) has dry road conditions for the contact surfaces of the front right tire, front left tire, and rear right tire, and only the road condition of the contact surface of the rear left tire is snow. In Fig. 5(a), the three vehicles 2 indicated by reference symbols (1) to (3) are each traveling straight ahead at a steady speed (constant velocity).

[0078] As shown in FIG. 5(b), for a vehicle 2 in the state indicated by the symbol (1), the drive mode determination unit 11, for a front, rear, left, and right independent drive system, selects a drive mode for each tire according to the road surface condition of the tire's contact surface (drive mode setting rule 1). That is, normal mode is selected as the drive mode for each of the front right tire, front left tire, and rear right tire. Snow mode is selected as the drive mode for the rear left tire. For a front, rear, and left independent drive system, the road surface condition of the tire's contact surface is dry, so normal mode is selected as the drive mode for the front tires. On the other hand, for the rear tires, different road surface conditions are detected at the contact surfaces of the left and right tires (because the road surface conditions are determined to be different), so drive mode setting rule 2 is applied, and snow mode, which has a higher priority, is selected as the drive mode for the rear tires. For a one-motor or one-engine drive system, because different road surface conditions are determined to be at the contact surfaces of the front, rear, left, and right tires, drive mode setting rule 3 is applied, and snow mode, which has a higher priority, is selected.

[0079] In addition, when the vehicle 2 is in the state indicated by the symbol (2), the road surface condition of the contact surfaces of both the front right tire and the rear right tire is dry, and the road surface condition of the contact surfaces of the front left tire and the rear left tire is snow. Therefore, for the front-rear, left-right, and rear-side independent drive system, the drive mode determination unit 11 selects normal mode as the drive mode for each of the front right tire and the rear right tire, and snow mode as the drive mode for the front left tire and the rear left tire, in accordance with drive mode setting rule 1. Furthermore, for the front-rear independent drive system, the drive mode setting rule 2 selects snow mode, which has the highest priority, as the drive mode for the front side and the drive mode for the rear side. For the one-motor or one-engine drive system, the drive mode setting rule 3 selects snow mode, which has the highest priority.

[0080] In addition, in the vehicle 2 in the state indicated by symbol (3), only the road surface condition of the contact surface of the front left tire is snow, and the road surface conditions of the contact surfaces of the front right tire, rear right tire, and rear left tire are all dry. Therefore, for the front, rear, left, and right independent drive system, the drive mode determination unit 11 selects snow mode as the drive mode for the front left tire and normal mode as the drive mode for each of the front right tire, rear right tire, and rear left tire in accordance with drive mode setting rule 1. Also, for the front and rear independent drive system, normal mode is selected as the drive mode for the rear side. For the front side drive mode, snow mode, which has a higher priority, is selected in accordance with drive mode setting rule 2. For the one-motor or one-engine drive system, snow mode, which has a higher priority, is selected in accordance with drive mode setting rule 3.

[0081] In Fig. 6(a), the road surface condition shown as snow in Fig. 4(a) is shown as dirt. In Fig. 6(a), three vehicles 2 indicated by symbols (1) to (3) are traveling straight. In Fig. 6(b), the all-tires-connected drive system is shown divided into two driving states: accelerating and decelerating.

[0082] In Figure 6(a), the vehicle 2 in the state indicated by reference symbol (1) has a dry road surface condition for the contact surfaces of both the front right tire and the front left tire, and a dirt road surface condition for the contact surfaces of both the rear right tire and the rear left tire. The vehicle 2 in the state indicated by reference symbol (2) has a dirt road surface condition for the contact surfaces of all tires. The vehicle 2 in the state indicated by reference symbol (3) has a dirt road surface condition for the contact surfaces of both the front right tire and the front left tire, and a dry road surface condition for the contact surfaces of both the rear right tire and the rear left tire.

[0083] For the all-tires-connected drive system, the drive mode determination unit 11 may apply drive mode setting rule 4 to set the drive mode according to the road surface conditions of the tire bearing the most load during both acceleration and deceleration. In other words, the drive mode determination unit 11 may set the drive mode according to the road surface conditions of the contact surface of the loaded tire.

[0084] For example, during acceleration while traveling straight, the rear tire is loaded, and the loaded tire becomes the rear tire, as shown in Fig. 3. Therefore, as shown in Fig. 6(b), during acceleration, the drive mode determination unit 11 may select a drive mode corresponding to the road surface condition of the contact surface of the rear tire for the vehicle 2 in each of the states indicated by symbols (1) to (3). Specifically, for the vehicle 2 in the states indicated by symbols (1) and (2), the drive mode determination unit 11 selects the gravel mode corresponding to dirt, and for the vehicle 2 in the state indicated by symbol (3), the drive mode determination unit 11 selects the normal mode corresponding to dry.

[0085] Furthermore, during deceleration while traveling straight, the load is on the front, and the loaded tire becomes the front tire, as shown in Fig. 3. Therefore, as shown in Fig. 6(b), the drive mode determination unit 11 may select a drive mode that corresponds to the road surface condition of the contact surface of the front tire during deceleration. Specifically, for the vehicle 2 in the state indicated by symbol (1), the normal mode corresponding to dry is selected, and for the vehicle 2 in the states indicated by symbols (2) and (3), the gravel mode corresponding to dirt is selected.

[0086] The front / rear / left / right independent drive system and the front / rear independent drive system are similar to the case where dry and snow are mixed, as shown in Figure 4(b). That is, for the front / rear / left / right independent drive system, the drive mode determination unit 11 sets the drive mode for each tire according to the road surface condition of the contact surface. For the front / rear independent drive system, the drive mode determination unit 11 sets the drive mode according to the road surface condition of the contact surface of each of the front tires and the rear tires.

[0087] In Fig. 7(a), the road surface conditions are a mixture of dirt and dry. In Fig. 7(a), three vehicles 2 indicated by symbols (1) to (3) are assumed to be traveling steadily (at a constant speed). In Fig. 7(b), the front and rear independent drive system is shown in each of the traveling states of turning left, going straight, and turning right.

[0088] In FIG. 7(a), the vehicle 2 in the state indicated by reference symbol (1) has dirt on the contact surfaces of the front right tire, front left tire, and rear left tire, and only the road surface condition of the contact surface of the rear right tire is dry. The vehicle 2 in the state indicated by reference symbol (2) has dirt on the contact surfaces of the front left tire and rear left tire, and only the road surface condition of the contact surfaces of the front right tire and rear right tire is dry. The vehicle 2 in the state indicated by reference symbol (3) has dirt on the contact surface of the front left tire, and only the road surface condition of the contact surfaces of the front right tire, rear left tire, and rear right tire is dry.

[0089] For the front and rear independent drive system, the drive mode determination unit 11 may apply drive mode setting rule 4 for both left and right turns to set the drive mode according to the road surface conditions of the tire bearing the most load.

[0090] For example, when turning left, the load is on the right side, so that the right tires are the loaded tires on both the rear and front sides of the vehicle 2, as shown in the "Normal" and "Left Turning" columns of Fig. 3. More specifically, between the rear right tire and the rear left tire on the rear side of the vehicle 2, the rear right tire is the loaded tire. Also, between the front right tire and the front left tire on the front side of the vehicle 2, the front right tire is the loaded tire.

[0091] Therefore, when different road surface conditions are detected for the contact patches of the left and right tires, as in the rear side of the vehicle 2 in the states indicated by symbols (1) and (2), the drive mode determination unit 11 selects the normal mode corresponding to the dry road surface condition of the contact patch of the rear right tire as the drive mode for the rear side in accordance with drive mode setting rule 4. Similarly, when the front side of the vehicle 2 is in the states indicated by symbols (2) and (3), the drive mode determination unit 11 selects the normal mode corresponding to the dry road surface condition of the contact patch of the front right tire as the drive mode for the front side.

[0092] Furthermore, when turning right, the load is on the left side, so that the left tires on both the rear and front sides of the vehicle 2 are the loaded tires, as shown in the "Normal" and "Right Turn" columns of Fig. 3. More specifically, between the rear right tire and rear left tire on the rear side of the vehicle 2, the rear left tire is the loaded tire. Furthermore, between the front right tire and front left tire on the front side of the vehicle 2, the front left tire is the loaded tire.

[0093] Therefore, when different road surface conditions are detected for the contact patches of the left and right tires, as in the rear side of the vehicle 2 in the states indicated by symbols (1) and (2), the drive mode determination unit 11 selects gravel mode, which corresponds to the road surface condition of the contact patch of the rear left tire, "dirt," in accordance with drive mode setting rule 4. Similarly, for the front side of the vehicle 2 in the states indicated by symbols (2) and (3), the drive mode determination unit 11 selects gravel mode, which corresponds to the road surface condition of the contact patch of the front left tire, "dirt," as the drive mode for the front side.

[0094] The drive mode determination unit 11 may continue to set the previous set value for each of the rear side of the vehicle 2 in state (1) when traveling straight, the front side of the vehicle 2 in state (2), the rear side of the vehicle 2 in state (2), and the front side of the vehicle 2 in state (3). That is, the drive mode determination unit 11 may set the normal mode if the previous value was the normal mode, the gravel mode if the previous value was the gravel mode, and the normal mode in other cases.

[0095] At the front side of the vehicle 2 in the state indicated by reference symbol (1), the road surface conditions of the contact surfaces of both left and right tires are dirt, so the drive mode determination unit 11 selects gravel mode as the drive mode for the front side, regardless of whether the vehicle 2 is turning left, traveling straight, or turning right. At the rear side of the vehicle 2 in the state indicated by reference symbol (3), the road surface conditions of the contact surfaces of both left and right tires are dry, so the drive mode determination unit 11 selects normal mode as the drive mode for the rear side, regardless of whether the vehicle 2 is turning left, traveling straight, or turning right.

[0096] In the case of a front, rear, left, and right independent drive system, the drive mode determination unit 11 sets the drive mode for each tire according to the road surface conditions of the contact surfaces. In the case of an all-tire connected drive system, the drive mode may be set according to a preset priority order or algorithm. For example, when turning left, the drive mode determination unit 11 may refer to the "Steady" and "Left Turn" columns in FIG. 3 and apply drive mode setting rule 4 to set the drive mode according to the road surface conditions of the tire bearing the heaviest load among the four tires (in this case, the rear right tire). When turning right, the drive mode determination unit 11 may refer to the "Steady" and "Right Turn" columns in FIG. 3 and apply drive mode setting rule 4 to set the drive mode according to the road surface conditions of the tire bearing the heaviest load among the four tires (in this case, the rear left tire). Alternatively, the drive mode determination unit 11 may apply drive mode setting rule 5 to set the drive mode according to the road surface conditions determined by majority vote among the road surface conditions of the contact surfaces of the four tires. When traveling straight, the drive mode determination unit 11 may apply drive mode setting rule 6 to set the drive mode according to the road surface conditions of the contact surfaces of the tires that serve as drive wheels. When the vehicle 2 is moving forward, the drive mode determination unit 11 may set the drive mode according to the road surface conditions of the contact surfaces of the front tires.

[0097] The drive mode selected (set) by the drive mode determination unit 11 is passed to the drive mode switching unit 7. The drive mode switching unit 7 switches the drive mode currently set in the vehicle 2 to the drive mode selected by the drive mode determination unit 11. The drive mode switching unit 7 may control the drive devices and / or braking devices mounted on the vehicle 2 so that the vehicle 2 travels in the selected drive mode. In other words, the drive mode switching unit 7 can also be described as a control unit that controls the drive devices and / or braking devices mounted on the vehicle 2 according to the selected drive mode. The drive mode switching unit 7 may be included in the control device 1 as a functional element of the control device 1.

[0098] [3. Flowchart] Fig. 8 is an example of a flowchart for explaining the above-described processing performed by the control device 1. The flowchart in Fig. 8 starts, for example, when the main power supply of the vehicle 2 is turned on. The flowchart in Fig. 8 ends, for example, when the main power supply of the vehicle 2 is turned off.

[0099] In step S1, the second road surface condition recognition unit 12b determines the road surface condition of the contact surface of each tire based on past images of the road surface in front of the vehicle that were captured by the front camera 4 and recorded in the past image recording unit 13. When the vehicle 2 is moving backward, the second road surface condition recognition unit 12b may determine the road surface condition of the contact surface of each tire based on past images of the road surface behind the vehicle that were captured by the rear camera 8 and recorded in the past image recording unit 13, as the processing of step S1.

[0100] In step S2, the first road surface condition recognition unit 12a determines the road surface condition of the contact surface of each tire based on the road surface image around the tire captured by the side camera 3.

[0101] In step S3, the loaded tire determination unit 14 determines, from among the plurality of tires mounted on the vehicle 2, the loaded tire on which the highest load is applied.

[0102] In step S4, the drive mode determination unit 11 identifies (determines) the road surface condition for each tire based on the road surface conditions determined by the first road surface condition recognition unit 12a and the second road surface condition recognition unit 12b.

[0103] In step S5, the drive mode determination unit 11 selects (sets) the drive mode of the vehicle 2 based on the identified road surface conditions for each tire and the loaded tire determined by the loaded tire determination unit .

[0104] In step S6, the control device 1 determines whether the termination condition is met. The termination condition may be, for example, that driving has ended and the main power supply of the vehicle 2 has been turned off. If it is determined in step S6 that the termination condition is not met, the process returns to step S1. If it is determined in step S6 that the termination condition is met, the process ends.

[0105] [4. Actions and Effects] (1) In the above-described control device 1, the second road surface condition recognition unit 12b determines the road surface condition of each tire's contact patch based on past road surface images included in the first road surface image. The first road surface condition recognition unit 12a determines the road surface condition around the tires based on the second road surface image. The drive mode determination unit 11 selects at least one drive mode from among a plurality of drive modes based on the road surface conditions of each tire's contact patch. The first road surface image is an image captured by cameras 4 and 8 that capture the road surface in the traveling direction of the vehicle 2, and the second road surface image is an image captured by camera 3 that captures the road surface in a direction different from the traveling direction.

[0106] In this way, by determining the contact patch of each tire using images captured by cameras 3, 4, and 8 and selecting a drive mode, the drive mode can be switched more quickly than known methods that switch drive modes based on, for example, the detection of vibration or slippage. Furthermore, by determining the contact patch of each tire based not only on the second road surface image but also on past road surface images included in the first road surface image, the detection accuracy of road surface conditions can be further improved. Therefore, a drive mode appropriate for the actual road surface conditions can be selected. Furthermore, by determining the road surface conditions of all tire contact patches when switching drive modes, a drive mode more appropriate for the road surface type can be selected, allowing the vehicle 2 to run in a drive mode more appropriate for the road surface type.

[0107] (2) During the daytime or in a non-low-illumination environment, while the vehicle 2 is traveling or immediately after stopping, the drive mode determination unit 11 uses the first detection method and the second detection method to identify the road surface condition for each tire. This allows the road surface condition of the contact surface of each tire to be determined with high accuracy.

[0108] (3) Immediately after powering on the vehicle 2 or after a certain time has elapsed since the vehicle 2 was stopped, the drive mode determination unit 11 uses the second detection method to determine the road surface condition of the contact surface of each tire. This makes it possible to determine the road surface condition of the contact surface of each tire with high accuracy even when the first road surface image is not available.

[0109] (4) Furthermore, when the vehicle 2 is traveling at night or in a low-light environment, the drive mode determination unit 11 uses the first detection method to determine the road surface condition of the contact surface of each tire. Because the area ahead of the vehicle 2 is illuminated by headlights, even at night or in a low-light environment, the second road surface condition recognition unit 12b can determine the road surface condition of each tire's contact surface from past road surface images included in the road surface image ahead of the vehicle 2. This makes it possible to determine the road surface condition of each tire's contact surface with high accuracy even when traveling at night or in a low-light environment.

[0110] (5) If the vehicle 2 is a front, rear, left, and right independent drive system, the drive mode determination unit 11 selects a drive mode for each of the front, rear, left, and right tires that corresponds to the road surface conditions of the contact surfaces of the respective tires. This allows vehicle control suited to the road surface conditions of the contact surfaces of each tire.

[0111] (6) If the vehicle 2 is a front and rear independent drive system and different road surface conditions are determined for the contact surfaces of the front or rear tires, the drive mode determination unit 11 selects the drive mode with the highest priority from among the drive modes corresponding to the determined road surface conditions for the left and right front or rear tires. This allows the vehicle 2 to run in the drive mode with the highest priority set for reasons such as safety.

[0112] (7) If the vehicle 2 is an all-wheel drive system and different road surface conditions are determined for the contact surfaces of the front, rear, left, and right tires, the drive mode determination unit 11 uniformly selects a drive mode with a higher priority among the drive modes corresponding to each determined road surface condition for all the front, rear, left, and right tires. This also allows the vehicle 2 to run in a drive mode with a higher priority that has been set for reasons such as safety.

[0113] (8) When drive mode determination unit 11 determines that the road surface conditions are different for the contact surfaces of two or more tires among the front, rear, left, and right tires, it may select a drive mode that corresponds to the road surface conditions of the contact surface of the tire that bears the most load among the two or more tires, according to the running state of vehicle 2. This allows vehicle control in the selected drive mode to be efficiently reflected in running.

[0114] (9) The drive mode determination unit 11 may select a drive mode that corresponds to the most frequently determined road surface condition among the road surface conditions of the tire contact surfaces. This allows the vehicle 2 to be controlled in accordance with the road surface condition on which the vehicle 2 is traveling.

[0115] (10) When the vehicle 2 is traveling straight, the drive mode determination unit 11 may select a drive mode that corresponds to the road surface condition of the contact surface of the tire that is the drive wheel among the plurality of tires. This allows vehicle control in the selected drive mode to be efficiently reflected in the driving.

[0116] [5. Other] The processing performed by the control device 1 described above is an example. The control device 1 described above may be applied to a vehicle equipped with at least a first camera and a second camera, and the vehicle 2 may not be a vehicle with a front / rear / left / right independent drive system (four-wheel independent drive system), a front / rear independent drive system, or a single motor or single engine (ENG) drive system. In the control device 1 described above, the loaded tire determination unit 14 may be omitted.

[0117] The first camera may be any camera that captures at least the road surface in the direction of travel of the vehicle, and does not have to be the front camera 4. Similarly, the second camera may be any camera that captures the road surface in a direction different from the direction of travel, and does not have to be the side camera 3. If reverse travel of the vehicle 2 is not taken into consideration, the rear camera 8 may be omitted.

[0118] In the control device 1 described above, the first road surface condition recognition unit 12a that determines the road surface condition of each of the plurality of tire contact surfaces based on the second road surface image, and the second road surface condition recognition unit 12b that determines the road surface condition of each of the plurality of tire contact surfaces based on past road surface images are provided as separate functional elements, but the control device 1 may be provided with a single functional element that has the functions of the first road surface condition recognition unit 12a and the second road surface condition recognition unit 12b as the road surface condition recognition unit. In this case, the road surface condition recognition unit may perform the process of the drive mode determination unit 11 described above that makes the final determination of the road surface condition of each of the plurality of tire contact surfaces. [Industrial Applicability]

[0119] The present invention is applicable to the manufacturing industry of vehicle control devices applied to vehicles, and also applicable to the manufacturing industry of vehicles equipped with such vehicle control devices. [Explanation of symbols]

[0120] 1. Control device (vehicle control device) 2 vehicles 3 Side camera (second camera) 3L Left camera (second camera) 3R Right camera (second camera) 4 Front camera (first camera) 5 Wheel speed sensor 6 Steering Sensor 7 Drive mode switch 8 Rear camera (first camera) 11 Drive mode determination unit (road surface condition recognition unit, drive mode determination unit) 12a First road surface condition recognition unit (road surface condition recognition unit) 12b Second road surface condition recognition unit (road surface condition recognition unit) 13 Past Footage Recording Department 14 Loaded tire determination section FLT front left tire RLT rear left tire

Claims

1. a road surface condition recognition unit that determines the road surface condition of each of the contact surfaces of a plurality of wheels provided on the vehicle based on a past road surface image included in a first road surface image captured by a first camera that captures the road surface in the traveling direction of the vehicle and a second road surface image captured by a second camera that captures the road surface in a direction different from the traveling direction; a drive mode determination unit that selects at least one drive mode from a plurality of drive modes based on the road surface condition of each of the ground contact surfaces of the plurality of wheels. A vehicle control device.

2. The road surface condition recognition unit While the vehicle is running or immediately after stopping, The road surface condition of each of the contact surfaces is determined using a first detection method using the past road surface image and a second detection method using the second road surface image.

2. The vehicle control device according to claim 1.

3. The road surface condition recognition unit Immediately after the power supply is turned on in the vehicle or after a certain period of time has elapsed since the vehicle was stopped, Using a second detection method that uses the second road surface image, the road surface condition of each of the contact surfaces is determined.

2. The vehicle control device according to claim 1.

4. The road surface condition recognition unit When the vehicle is running at night or in a low light environment, The road surface condition of each of the contact surfaces is determined using a first detection method that uses the past road surface images.

2. The vehicle control device according to claim 1.

5. The drive mode determination unit If the vehicle is a front, rear, left and right independent drive system, A drive mode corresponding to the road surface condition of each of the contact surfaces of the front, rear, left, and right wheels is selected for each of the front, rear, left, and right wheels.

2. The vehicle control device according to claim 1.

6. The drive mode determination unit In the case where the vehicle is a front and rear independent drive system, When it is determined that the road surface conditions are different between the contact surfaces of the front or rear left and right wheels, A drive mode having a higher priority among the drive modes corresponding to each of the determined road surface conditions is selected for the left and right wheels.

2. The vehicle control device according to claim 1.

7. The drive mode determination unit In the case where the vehicle has an all-wheel drive system, When it is determined that the road surface conditions are different between the contact surfaces of the front, rear, left, and right wheels, A drive mode having a high priority among the drive modes corresponding to each of the determined road surface conditions is selected for the front, rear, left, and right wheels.

2. The vehicle control device according to claim 1.

8. The drive mode determination unit When it is determined that the road surface conditions are different between two or more wheels in the front, rear, left, and right wheels, In the running state of the vehicle, a drive mode corresponding to the road surface condition of the contact surface of the wheel that receives the most load among the two or more wheels is selected.

2. The vehicle control device according to claim 1.

9. The drive mode determination unit A drive mode corresponding to the most frequently determined road surface condition among the road surface conditions of the contact surfaces of the plurality of wheels is selected.

2. The vehicle control device according to claim 1.

10. The drive mode determination unit When the vehicle is traveling straight, a drive mode corresponding to the road surface condition of the ground contact surface of a drive wheel among the plurality of wheels is selected.

2. The vehicle control device according to claim 1.

Images