Vehicle control system

Abstract

To provide a vehicle control system capable of performing proper automatic brake control according to the surrounding environment of a vehicle.SOLUTION: A vehicle control system 1 includes: a collision determination section 21a that determines a possibility of collision with a target obstacle present in front of a vehicle; a brake control section 21b that controls braking force so as to perform automatic brake control according to the collision possibility determined by the collision determination section 21a; an environment recognition section 22 that recognizes a surrounding environment of the vehicle; a state recognition section 23 that recognizes a detection state of an obstacle around the vehicle; and a control adjustment section 24 that changes a type of the target obstacle in the automatic brake control and a lower limit value of vehicle speed for starting the automatic brake control on the basis of the surrounding environment of the vehicle recognized by the environment recognition section 22 and the detection state recognized by the state recognition section 23.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle control system. [Background technology]

[0002] Systems that support safety when a collision between a vehicle and an obstacle ahead is predicted are being put into practical use. Known safety support systems include a collision mitigation braking system that automatically activates the brakes and / or an alarm, and a so-called pedestrian airbag system that protects a person in a collision with a vehicle. Patent Document 1 discloses a protection control device that activates a protection device to protect a collided object when the output of a collision sensor corresponding to the impact applied during a collision between the object and the vehicle exceeds a collision detection threshold. In the device of Patent Document 1, the object is a specific object, including a bicycle and a bicycle rider, and the collision detection threshold is set to a low threshold when an obstructing environment, such as rain or fog, occurs that obstructs recognition of the object before the collision. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-081428 Summary of the Invention [Problem to be solved by the invention]

[0004] The protection control device described in the aforementioned Patent Document 1 changes the collision determination threshold based on whether the object is a specific object and whether an obstructing environment, such as rain or fog, is occurring. Even in a system that performs collision mitigation braking control when a collision between a vehicle and an obstacle is predicted, it is desirable to perform control taking into account the environment around the vehicle. For example, in an environment where multiple types of obstacles, including four-wheeled vehicles, motorcycles, and pedestrians, are present around the vehicle, performing automatic braking control targeting the obstacle ahead may cause the vehicle to slow down, potentially resulting in a rear-end collision with a following vehicle. In this case, the reliability and safety of the system are reduced. On the other hand, in an environment where there are few obstacles around the vehicle, it is desirable to reliably perform automatic braking control when there is a possibility of a collision with an obstacle. In other words, it is desirable to improve the safety and reliability of the system and perform appropriate automatic braking control according to the environment around the vehicle.

[0005] The present invention has been made in consideration of the above-described circumstances, and its purpose is to provide a vehicle control system that can execute appropriate automatic brake control in accordance with the surrounding environment of the vehicle. [Means for solving the problem]

[0006] According to one aspect of the present invention, a vehicle control system includes a collision determination unit that determines the possibility of a collision with a target obstacle present in front of the vehicle, a brake control unit that controls the braking force to perform automatic brake control in accordance with the possibility of collision determined by the collision determination unit, an environment recognition unit that recognizes the surrounding environment of the vehicle, a situation recognition unit that recognizes the detection status of obstacles around the vehicle, and a control adjustment unit that changes the type of target obstacle in the automatic brake control and the lower vehicle speed limit value for starting the automatic brake control based on the surrounding environment of the vehicle recognized by the environment recognition unit and the detection status recognized by the situation recognition unit. [Effects of the Invention]

[0007] The vehicle control system according to the present invention can execute appropriate automatic brake control in accordance with the surrounding environment of the vehicle. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a vehicle control system according to an embodiment of the present invention. [Figure 2] FIG. 2 shows a specific example of a control pattern for automatic brake control in one embodiment. [Figure 3] FIG. 3 shows a specific example of a control pattern for automatic brake control in one embodiment. [Figure 4] FIG. 4 is a flowchart showing a procedure for selecting a control pattern for automatic brake control in one embodiment. [Figure 5] FIG. 5 is a flowchart showing a procedure for selecting a control pattern for automatic brake control based on the detection status of an obstacle. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle control system according to an embodiment of the present invention will now be described in detail with reference to the drawings. Figure 1 is a block diagram showing a schematic configuration of the vehicle control system according to this embodiment.

[0010] 1, the vehicle control system 1 includes, for example, an imaging device 10 that captures images of the area surrounding the vehicle, an obstacle detection device 11 that detects obstacles around the vehicle, a vehicle speed sensor 12 that detects the vehicle speed, a positioning device 13 that acquires vehicle position information, a map information database 14, a control device 20 that performs control related to collision damage mitigation brake control for the vehicle, and a brake device 30. The vehicle control system 1 according to this embodiment is configured to be mounted on a vehicle and to perform control related to collision damage mitigation brake control for the vehicle. Optionally, the vehicle control system 1 may further include an operation input device 15, an alarm device 40, and a display device 50.

[0011] The image capturing device 10 has a digital camera with an image capturing element such as a CCD or CMOS, and is configured to output information about the area around the vehicle, particularly the area ahead including obstacles around the vehicle, as still images and / or video. The image data of the area captured by the image capturing device 10 is input to the control device 20.

[0012] The obstacle detection device 11 is configured to detect obstacles around the vehicle and measure the relative position and relative distance (inter-vehicle distance) between the vehicle and the obstacle. For example, a millimeter-wave radar, a camera, a sonar sensor, or a LiDAR (Light Detection and Ranging) can be used as the obstacle detection device 11. The above-mentioned imaging device 10 can also be used as the obstacle detection device 11. Detection of obstacles by the obstacle detection device 11 is dynamically performed at a predetermined measurement period. Information about obstacles detected by the obstacle detection device 11 and the vehicle speed detected by the vehicle speed sensor 12 are input to the control device 20.

[0013] The positioning device 13 is configured to acquire vehicle position information based on information from, for example, a Global Navigation Satellite System (GNSS), etc. The vehicle position information acquired by the positioning device 13 and the map information in the map information database 14 are input to the control device 20.

[0014] The operation input device 15 is configured to accept various operation inputs to the vehicle by a user, for example, the driver. The operation input device 15 includes a switch operated by the driver to turn on or off the collision damage mitigation brake function, a function changeover switch operated by the driver to enable or disable a function for adjusting the control content of the collision damage mitigation brake control described below, and the like. The operation input device 15 may be configured as, for example, a touch panel integrated with the display of the alarm device 40 or the display device 50 described below.

[0015] The control device 20 is configured by a computer including, for example, a ROM that stores programs and data, a CPU that performs arithmetic processing, a RAM that stores dynamic data and arithmetic processing results, an input / output interface, etc. The control device 20 is configured to execute functions of an AEB control unit 21, an environment recognition unit 22, a situation recognition unit 23, a control adjustment unit 24, etc., and to control the entire vehicle control system 1. Note that the vehicle control system 1 may also implement the AEB control unit 21 as a controller separate from the control device 20.

[0016] The AEB control unit 21 is configured to perform so-called autonomous emergency braking (AEB) control, which applies automatic braking to the driver depending on the possibility of a collision between the vehicle and an obstacle. The collision mitigation braking control performed by the AEB control unit 21 is automatic braking control that causes the brake device 30 to generate a strong braking force when it is determined that there is a high possibility of a collision with an obstacle. The AEB control unit 21 includes, for example, a collision determination unit 21a and a brake control unit 21b. Although a detailed description will be omitted, the AEB control unit 21 can also be configured to perform warning control, as the collision mitigation braking control, in which, when it is determined that there is a risk of a collision with an obstacle, the warning device 40 issues a warning to prompt the driver to apply the brakes.

[0017] The collision determination unit 21a is configured to determine the possibility of a collision between the vehicle and an obstacle based on image data of the area ahead of the vehicle and the relative distance to the obstacle ahead of the vehicle, which are input from the imaging device 10 and the obstacle detection device 11. The collision determination unit 21a can calculate, for example, a time-to-collision (TTC) required for the vehicle to approach and come into contact with the obstacle as the possibility of collision. Specifically, the collision determination unit 21a calculates the relative speed between the vehicle and the obstacle, which represents the change in relative distance per unit time, from the relative distance to the obstacle, and calculates the predicted time-to-collision (TTC) as a value obtained by dividing the relative distance by the relative speed.

[0018] The collision determination unit 21a can also calculate the predicted time to collision TTC between the vehicle and an obstacle crossing in front of the vehicle. In this case, the collision determination unit 21a calculates the relative speed between the vehicle and the obstacle by using, for example, the longitudinal speed component of the obstacle as the speed of the obstacle in the longitudinal direction of the vehicle. That is, the collision determination unit 21a can calculate the predicted time to collision TTC with the obstacle crossing in front of the vehicle by dividing the relative distance between the vehicle and the obstacle by the relative speed that takes into account the vehicle speed of the vehicle and the longitudinal speed component of the obstacle.

[0019] The brake control unit 21b is configured to control the brake device 30 so as to generate a braking force equivalent to the maximum deceleration of the system, for example, when the collision prediction time TTC calculated by the collision judgment unit 21a is equal to or less than a preset threshold value.

[0020] The braking device 30 includes a brake (e.g., a disc brake, a drum brake, etc.) provided on the wheel, a brake actuator connected to the brake via hydraulic piping, and a brake controller, and is configured to control the hydraulic pressure in accordance with a deceleration command from the control device 20 and control the braking force of the brake.

[0021] The notification device 40 is configured to issue an alarm in response to a command from the control device 20. The notification device 40 can issue an alarm, for example, when there is a risk of collision with an obstacle and / or when there is a high possibility of collision with an obstacle. The notification device 40 has, for example, a display, indicator lights, a speaker, etc. arranged on an instrument panel at the front of the vehicle, and can issue a warning to the driver visually and / or audibly. The notification device 40 can also be configured to issue a warning through the sense of touch, for example. The display device 50 is, for example, composed of a liquid crystal display installed on the instrument panel, and is configured to display an image on the display screen in response to a command from the control device 20.

[0022] As described above, the vehicle control system 1 according to this embodiment is configured to perform automatic brake control using the AEB control unit 21 in response to the possibility of a collision between the vehicle and an obstacle ahead of the vehicle. Here, obstacles around the vehicle include various types of objects, such as four-wheeled vehicles, motorcycles, bicycles, and pedestrians. The surrounding environment of the vehicle, such as the types and amounts of obstacles around the vehicle, may vary depending on, for example, the region or country in which the vehicle is traveling. Furthermore, driver characteristics, such as the distance the driver maintains between the vehicle and a preceding vehicle during normal driving, may also vary depending on the region or country.

[0023] In some regions or countries, drivers tend to drive slowly and closely to the vehicle in front in crowded urban areas where there are many vehicles, motorcycles, bicycles, and pedestrians, or to stop only after approaching the vehicle in front. In such environments, automatic braking may be excessively performed if collision mitigation braking control is performed for all types of obstacles using the same activation conditions as in other regions or countries. In some situations, automatic braking control may slow the vehicle down, potentially inducing a collision between the vehicle and a following vehicle. This may result in a loss of system safety and reliability. On the other hand, even in regions or countries with driver characteristics such as those described above, automatic braking is expected to be reliably performed when there is a high possibility of a collision with an obstacle in front of the vehicle in environments where there are few obstacles around the vehicle and the possibility of a rear-end collision from a following vehicle is low.

[0024] Therefore, in this embodiment, the control is adjusted to execute appropriate collision mitigation braking control according to the vehicle's surrounding environment and the obstacle detection status. Here, the adjustment of control includes changing the type of obstacle that is the target of the automatic braking control of the collision mitigation braking system and changing the activation start conditions of the automatic braking control. For example, the control device 20 changes the type of obstacle that is the target of the automatic braking control and changes the activation start conditions of the automatic braking control depending on whether the vehicle's surrounding environment is a predetermined area within a specific region. Furthermore, taking into account the detection status of obstacles present around the vehicle, the control device 20 changes the type of obstacle that is the target of the automatic braking control and changes the activation start conditions of the automatic braking control. The adjustment of the automatic braking control will be described in detail below.

[0025] In order to adjust the automatic brake control, the control device 20 has an environment recognition unit 22, a situation recognition unit 23, and a control adjustment unit 24. The environment recognition unit 22 is configured to recognize whether the environment around the vehicle is a predetermined area within a specific region for adjusting the automatic brake control, based on information input from the imaging device 10, the obstacle detection device 11, the positioning device 13, etc.

[0026] In this embodiment, the term "specific region" refers to a country or region with a high population density, where drivers tend to drive slowly in crowded urban areas, etc., where there are many vehicles, motorcycles, bicycles, and pedestrians, and to approach the vehicle in front at a low speed and close to it, or to stop only after getting as close as possible to the vehicle in front. A specific region may be, for example, India, while a region that does not fall under the specific region may be, for example, Japan. The specific region is not limited to a single country, and may be a part of a country, or a region consisting of multiple countries, such as the Association of Southeast Asian Nations (ASEAN).

[0027] In this embodiment, the "predetermined area" refers to a location within the specific region described above, such as a suburban or rural area, where multiple types of obstacles are not densely located. For example, in an area where vehicles tend to drive closely with the vehicle in front, such as an urban or busy area where multiple types of obstacles are intertwined, the automatic brake control may be activated excessively or unnecessarily. Furthermore, executing the automatic brake control to target all types of obstacles around the vehicle may actually induce a collision between the vehicle and the obstacle. On the other hand, in an environment such as a suburban or rural area where multiple types of obstacles are not densely located, the automatic brake control is expected to be able to fully function by targeting the obstacles present there.

[0028] Therefore, in this embodiment, an area where multiple types of obstacles are not densely located, such as a suburban area or a rural area, can be specified as the predetermined area. By adjusting the control content of the automatic brake control between an environment where multiple types of obstacles are densely located, such as an urban area or a busy street, and an environment where multiple types of obstacles are not densely located, such as a suburban area or a rural area, the automatic brake control can be performed appropriately according to the surrounding environment of the vehicle.

[0029] The environment recognition unit 22 can, for example, register in advance in the map information base 13 as a specific region a country or region where drivers have the characteristic of driving close to the vehicle in front or stopping as close as possible to the vehicle in front, and recognize that the environment around the vehicle is within the specific region when the current position of the vehicle is within the specific region.

[0030] The environment recognition unit 22 can also recognize whether the vehicle's surrounding environment is within a predetermined area, for example, based on the density of obstacles within a predetermined range around the vehicle. The environment recognition unit 22 identifies the type of obstacle using a technique such as pattern matching based on obstacle information input from the imaging device 10 and the obstacle detection device 11, and calculates the density of specific obstacles within the predetermined area. Here, the specific obstacle may be, for example, a pedestrian. If the density of obstacles within the predetermined area is low, the environment recognition unit 22 recognizes that the area is a predetermined area such as a suburban or rural area where obstacles are not densely concentrated.

[0031] Alternatively, the environment recognition unit 22 may register in advance in the map information database 13 a predetermined area such as a suburb or a countryside where obstacles are not densely concentrated, and recognize that the surrounding environment of the vehicle is in the predetermined area when the current position of the vehicle is within the registered predetermined area. In this case, the predetermined area may be set as a geographical area other than an area classified as an urban area or a busy street, that is, an area where multiple types of obstacles (for example, pedestrians, bicycles, and vehicles) are expected to exist in large numbers.

[0032] Alternatively, the environment recognition unit 22 may determine whether the vehicle is traveling in an area classified as an urban area or a busy street, based on image data of the area in front of the vehicle input from the imaging device 10 and the vehicle speed acquired from the vehicle speed sensor 12. For example, when a plurality of buildings are lined up along the road in front of the vehicle and the vehicle is traveling at a low speed, the environment recognition unit 22 can determine that the vehicle is traveling in an area classified as an urban area or a busy street and that the vehicle is outside a predetermined area.

[0033] The situation recognition unit 23 recognizes the detection status of obstacles around the vehicle based on information input from the imaging device 10, the obstacle detection device 11, the vehicle speed sensor 12, the positioning device 13, etc. In this embodiment, the detection status of an obstacle refers to the status of the detected obstacle, such as the type of obstacle detected by the imaging device 10 and the obstacle detection device 11, the relative position of the obstacle with respect to the vehicle, and the direction and speed of movement of the obstacle with respect to the vehicle.

[0034] Specifically, the situation recognition unit 23 is configured to recognize, as obstacle detection situations, the predicted collision position between the vehicle and the obstacle, the presence or absence of an obstacle crossing in front of the vehicle, and the predicted collision time TTCr between the vehicle and a following vehicle. As the predicted collision position between the vehicle and the obstacle, the situation recognition unit 23 preferably calculates, in particular, the predicted collision position between the vehicle and an obstacle other than a four-wheeled vehicle. Similarly, when recognizing the presence or absence of an obstacle crossing in front of the vehicle, it is preferable to determine whether an obstacle other than a four-wheeled vehicle is crossing in front of the vehicle. Obstacles other than four-wheeled vehicles include, for example, pedestrians, bicycles, and motorcycles.

[0035] The predicted collision position between the vehicle and an obstacle refers to the position where the vehicle and the obstacle are predicted to collide if they proceed at their current speed and direction of travel. For example, if the obstacle is a pedestrian crossing in front of the vehicle, the predicted collision position represents the position where the pedestrian will be located in the width direction of the vehicle when the vehicle reaches the position where the pedestrian is located in the fore-and-aft direction of the vehicle. The predicted collision position can be defined as being in the direction of travel of the vehicle if it is within the range between the right and left ends of the vehicle in the width direction of the vehicle. The situation recognition unit 23 can calculate the predicted collision position between the vehicle and the pedestrian based on information such as the fore-and-aft distance from the vehicle to the pedestrian input from the imaging device 10 and the obstacle detection device 11, the pedestrian's moving direction and moving speed, and the vehicle speed input from the vehicle speed sensor 12.

[0036] For example, in a traffic segment where traffic keeps to the left, if the predicted collision position is in the left region in the vehicle width direction, the vehicle can easily avoid the pedestrian by steering to the right, but if the predicted collision position is in the right region in the vehicle width direction, the vehicle cannot easily avoid the pedestrian by steering to the right. In other words, by recognizing the predicted collision position with an obstacle, it is possible to recognize whether the obstacle can be easily avoided by the driver's driving operation, i.e., the certainty of the possibility of a collision with the obstacle. Note that the situation recognition unit 23 can also calculate the predicted collision position between the vehicle and the obstacle when the obstacle is a bicycle or motorcycle other than a pedestrian.

[0037] The predicted time to collision TTCr between the vehicle and the following vehicle is a value obtained by dividing the relative speed between the vehicle and the following vehicle by the relative distance. If the predicted time to collision TTCr between the vehicle and the following vehicle is short, the vehicle is more likely to be rear-ended by the following vehicle when the vehicle executes automatic brake control. On the other hand, if the predicted time to collision TTCr between the vehicle and the following vehicle is long, the vehicle's automatic brake control can be safely executed in relation to the following vehicle. The situation recognition unit 23 can calculate the predicted time to collision TTCr between the vehicle and the following vehicle based on the relative speed and relative distance between the vehicle and the following vehicle input from, for example, the imaging device 10 and the obstacle detection device 11.

[0038] It is preferable that the situation recognition unit 23 calculates the change in the relative distance and relative speed between the vehicle and the following vehicle based on the deceleration of the vehicle for executing automatic brake control, and calculates the predicted collision time TTCr between the vehicle and the following vehicle when automatic brake control is executed.

[0039] The situation recognition unit 23 is also configured to recognize what obstacles there are based on image data input from the imaging device 10. The situation recognition unit 23 can recognize obstacles such as four-wheeled vehicles, motorcycles, bicycles, pedestrians, and animals by using image recognition technology based on deep learning, for example.

[0040] The control adjustment unit 24 adjusts the automatic brake control based on the recognition results of the environment recognition unit 22 and the situation recognition unit 23, changes the type of obstacle subject to the automatic brake control, and changes the activation start condition for the automatic brake control. Here, the activation start condition for the automatic brake control is, for example, the lower limit value of the vehicle speed when activation of the automatic brake control is initiated. The AEB control unit 21 initiates activation of the automatic brake control when the predicted collision time TTC between the vehicle and the obstacle is equal to or less than a predetermined threshold and the vehicle speed is equal to or greater than the lower limit value of the vehicle speed. In other words, even if the predicted collision time TTC between the vehicle and the obstacle is equal to or less than the predetermined threshold, the AEB control unit 21 does not initiate activation of the automatic brake control when the vehicle speed is below the lower limit value of the vehicle speed.

[0041] In addition, the control adjustment unit 24 may be configured to notify the driver that the adjustment function for the control content of the collision damage mitigation brake control has been enabled, and by displaying the adjusted control content of the automatic brake control, for example, on the display device 50.

[0042] Specific examples of control patterns for automatic brake control that are adjusted according to the vehicle's surrounding environment and the detection status of obstacles are shown below with reference to Figures 2 and 3. The reference pattern shown in Figure 2 is an unadjusted control pattern, and control patterns 1 to 6 shown in Figures 2 and 3 are adjusted control patterns.

[0043] A: Reference pattern The reference pattern shown in FIG. 2 is a default pattern for automatic brake control. In the reference pattern, target obstacles and a lower limit vehicle speed for initiating automatic brake control differ depending on whether the surrounding environment of the vehicle is a specific region (e.g., India) or outside the specific region (a general region, e.g., Japan). Specifically, target obstacles outside the specific region are four-wheeled vehicles and pedestrians, while target obstacles in the specific region are only four-wheeled vehicles. The lower limit vehicle speed (e.g., approximately 10 km / h) when a pedestrian is detected outside the specific region is set to a value higher than the lower limit vehicle speed (e.g., approximately 2 km / h) when a four-wheeled vehicle is detected. Furthermore, the lower limit vehicle speed (e.g., approximately 10 km / h) when a four-wheeled vehicle is detected in the specific region is the same regardless of whether the vehicle is within a predetermined region or not, but is set to a value higher than the lower limit vehicle speed (e.g., approximately 2 km / h) when a four-wheeled vehicle is detected outside the specific region.

[0044] In certain areas, where drivers tend to drive close to the vehicle in front in situations where obstacles are congested, or to stop only after approaching the vehicle in front as close as possible, if automatic braking control is performed with pedestrians as the target obstacle, the automatic braking control may be activated excessively or unnecessarily. Therefore, pedestrians are not set as target obstacles in certain areas. Also, if automatic braking control is allowed to start operating at low speeds (e.g., approximately 2 km / h), the automatic braking control may be activated excessively if the driver intentionally approaches the vehicle in front at a low speed. Therefore, by setting the minimum vehicle speed limit in certain areas to a value higher than the minimum vehicle speed limit outside the certain area, excessive activation of the automatic braking control is suppressed.

[0045] B: Control pattern 1 In control pattern 1 shown in Fig. 2, the target obstacles and the vehicle speed lower limit for initiating automatic brake control differ depending on whether the vehicle is in a predetermined area within a specific region. Specifically, the target obstacles in a specific region are only four-wheeled vehicles outside the predetermined area (e.g., urban areas), but in a predetermined area (e.g., suburban areas), the target obstacles include pedestrians in addition to four-wheeled vehicles. The vehicle speed lower limit (e.g., approximately 2 km / h) when a four-wheeled vehicle is detected within a predetermined area within the specific region is set to a value smaller than the vehicle speed lower limit (e.g., approximately 10 km / h) when a four-wheeled vehicle is detected outside the predetermined area within the specific region. Furthermore, the vehicle speed lower limit (e.g., approximately 10 km / h) when a pedestrian is detected within a predetermined area within the specific region is set to a value larger than the vehicle speed lower limit (e.g., approximately 2 km / h) when a four-wheeled vehicle is detected and is the same as the vehicle speed lower limit (e.g., approximately 10 km / h) when a pedestrian is detected outside the specific region.

[0046] In specific regions, the presence of many vehicles and pedestrians in urban areas outside the specified area can lead to excessive or unnecessary activation of automatic braking control. On the other hand, in suburban areas, which are specified areas, vehicles and pedestrians are not densely packed. Therefore, even if pedestrians are designated as target obstacles, damage mitigation braking control can be implemented while suppressing excessive or unnecessary activation. Furthermore, since the likelihood of other vehicles cutting in while traveling at low speeds in the specified area is considered low, automatic braking control can be implemented even at low speeds by setting the minimum vehicle speed limit for automatic braking control to a value lower than the minimum vehicle speed limit outside the specified area and the same as the minimum vehicle speed limit outside the specified area. Furthermore, when automatic braking control of a leading vehicle is implemented in the specified area to target a pedestrian, the leading vehicle's speed decreases. However, by setting the minimum vehicle speed limit for four-wheeled vehicles to a low speed (approximately 2 km / h), automatic braking control of the vehicle can be implemented even when the leading vehicle's speed decreases.

[0047] C: Control pattern 2 Control pattern 2 shown in Fig. 2 is an alternative pattern to the above-mentioned control pattern 1, and differs from control pattern 1 only in the lower limit vehicle speed (e.g., about 5 km / h) when a four-wheeled vehicle is detected within a predetermined area in a specific region. The lower limit vehicle speed (e.g., about 5 km / h) when a four-wheeled vehicle is detected within a predetermined area in a specific region in control pattern 2 is set to a value greater than the lower limit vehicle speed (e.g., about 2 km / h) when a four-wheeled vehicle is detected outside the specific region in the reference pattern.

[0048] The lower limit vehicle speed in a specified area of ​​a specific region is set to be higher than the lower limit vehicle speed outside the specific region, but lower than the lower limit vehicle speed outside the specified area of ​​the specific region, thereby precisely setting the lower limit vehicle speed at which automatic brake control is initiated in the specific region.

[0049] D: Control pattern 3 Control pattern 3 shown in Fig. 2 is an alternative to control pattern 1 described above, and is selected taking into consideration the predicted collision position between the vehicle and a pedestrian. In control pattern 3, for example, if the predicted collision position between the vehicle and a pedestrian is in the vehicle's traveling direction within a predetermined area within a specific region, the pedestrian is added as a target obstacle. The lower limit vehicle speed (e.g., approximately 30 km / h) when a pedestrian is detected within the predetermined area within the specific region is set to a value greater than the lower limit vehicle speed (e.g., approximately 10 km / h) when a pedestrian is detected outside the specific region.

[0050] If the predicted collision location between a vehicle and a pedestrian is in the vehicle's direction of travel within a specified area within a specific region and there is a high possibility of a collision, it is assumed that the driver is not intentionally approaching the pedestrian at a low speed, but rather that the driver is overlooking the pedestrian. Therefore, by setting the lower limit of the vehicle speed at which automatic brake control begins to be applied to a relatively large value, unnecessary application can be suppressed and automatic brake control can be applied safely.

[0051] E: Control pattern 4 Control pattern 4 shown in Fig. 3 is a control pattern when a bicycle is included as a target obstacle. In control pattern 4, for example, when a bicycle is detected crossing in front of a vehicle within a predetermined area in a specific region, a bicycle is added as a target obstacle. The lower vehicle speed limit (e.g., approximately 30 km / h) when a bicycle crossing in front of a vehicle is detected within a predetermined area in a specific region is set to a value greater than the lower vehicle speed limit (e.g., approximately 10 km / h) when a bicycle is detected outside the specific region.

[0052] Bicycles may slip through vehicles or suddenly run into the roadway and then off the roadway, resulting in an unfixed path, which may result in false detection by the imaging device 10 and obstacle detection device 11 and unnecessary activation of the automatic brake control. Therefore, by limiting the high-risk situation of a bicycle crossing in front of a vehicle to a specified area in a specific region and setting the lower limit vehicle speed for initiating automatic brake control to a relatively large value, unnecessary activation can be suppressed and the automatic brake control can be activated safely.

[0053] F: Control pattern 5 Control pattern 5 shown in Fig. 3 is a control pattern when a motorcycle is included as a target obstacle. In control pattern 5, for example, when a motorcycle is present crossing in front of a vehicle within a predetermined area within a specific region and the predicted position of a collision between the vehicle and the motorcycle is in the vehicle's traveling direction, the motorcycle is added as a target obstacle. The lower limit vehicle speed (e.g., approximately 30 km / h) when a motorcycle is detected crossing in front of a vehicle within a predetermined area within the specific region is set to a value greater than the lower limit vehicle speed (e.g., approximately 10 km / h) when a motorcycle is detected outside the specific region.

[0054] In control pattern 5, the threshold value of the collision prediction time TTC when automatic brake control is performed on a motorcycle within a predetermined area in a specific region is further changed. Specifically, the threshold value of the collision prediction time TTC between a vehicle and a motorcycle for determining the possibility of a collision within a predetermined area in a specific region is set to be smaller than the threshold value of the collision prediction time TTC between a vehicle and a motorcycle for determining the possibility of a collision outside the specific region. In other words, the timing to start automatic brake control on a motorcycle within a predetermined area in a specific region is delayed.

[0055] Motorcycles are faster than bicycles and often make sudden lane changes, such as passing through other vehicles, so there is a high possibility of false detection by the imaging device 10 and the obstacle detection device 11, and of unnecessary activation of the automatic brake control. Therefore, by limiting the situation to high-risk situations in which the predicted collision position between a vehicle and a motorcycle is in the vehicle's direction of travel in a predetermined area of ​​a specific region, and by setting the lower limit of the vehicle speed at which the automatic brake control starts to a relatively large value, and by changing the threshold for the collision prediction time to a small value, unnecessary activation can be suppressed and the automatic brake control can be safely activated.

[0056] G: Control pattern 6 Control pattern 6 shown in Fig. 3 is a control pattern when an animal is included as a target obstacle. In control pattern 6, for example, when the predicted time TTCr to a collision between the vehicle and a following vehicle is equal to or longer than a predetermined time Thr within a predetermined area within a specific region, an animal present in front of the vehicle is added as a target obstacle. The lower limit vehicle speed (e.g., approximately 10 km / h) when an animal is detected in front of the vehicle within a predetermined area within the specific region is set to the same value (e.g., approximately 10 km / h) as the lower limit vehicle speed when an animal is detected in front of the vehicle outside the specific region.

[0057] Although animals are difficult to detect using the imaging device 10 and the obstacle detection device 11, when the predicted time to collision with a following vehicle TTCr is long and the possibility of a collision with a following vehicle is low, even if automatic braking control is performed for an animal, secondary damage such as a collision with a following vehicle will not occur. Furthermore, by setting the lower limit vehicle speed for animals to a relatively small value, automatic braking control can be performed safely. Here, the predetermined time Thr for the predicted time to collision with a following vehicle TTCr is set to a time that can be considered to be able to reliably avoid a collision with a following vehicle even if the automatic braking control of the vehicle is activated and the vehicle decelerates.

[0058] Control patterns 4 to 6 may be used as alternative patterns to the above-mentioned reference pattern and control patterns 1 to 3, or may be used in combination with any of the reference pattern and control patterns 1 to 3. Note that the vehicle speed lower limit values ​​shown for the above-mentioned reference pattern and control patterns 1 to 3 are merely examples, and are not limited to these values.

[0059] The procedure for selecting a control pattern for automatic brake control in this embodiment will be described in detail below with reference to the flowchart in Fig. 4. The selection of the control pattern shown in Fig. 4 is performed when the driver operates the operation input device 15 to enable the adjustment function for the control content of the collision damage mitigation brake.

[0060] In step S101, the environment recognition unit 22 recognizes the environment around the vehicle based on information input from the imaging device 10, the obstacle detection device 11, the positioning device 13, etc., and the situation recognition unit 23 recognizes the detection status of obstacles around the vehicle based on information input from the imaging device 10, the obstacle detection device 11, the vehicle speed sensor 12, the positioning device 13, etc. The environment recognition unit 22 recognizes, for example, whether the current position of the vehicle is within a specific area or a predetermined region. The situation recognition unit 23 recognizes, for example, as the obstacle detection status, the predicted collision position between the vehicle and the obstacle, the presence or absence of an obstacle crossing in front of the vehicle, and the predicted collision time TTCr between the vehicle and a following vehicle.

[0061] In step S102, the environment recognition unit 22 determines whether the environment around the vehicle corresponds to the specific area described above. If the environment around the vehicle corresponds to the specific area, the process proceeds to step S103. In step S103, the environment recognition unit 22 determines whether the environment around the vehicle corresponds to a predetermined area in the specific area described above. If the environment around the vehicle corresponds to a predetermined area in the specific area, the process proceeds to step S104, where the control adjustment unit 24 selects a control pattern based on the detection status of an obstacle.

[0062] On the other hand, if step S102 or S103 is judged negative, meaning the vehicle's surroundings do not fall within the specific area or the predetermined region of the specific area, the process proceeds to step S105. In step S105, the control adjustment unit 24 selects the above-mentioned reference pattern as the control pattern for automatic brake control. As a result, automatic brake control is executed in accordance with the target obstacles and vehicle speed lower limit defined in the reference pattern.

[0063] The procedure for selecting a control pattern based on the obstacle detection status in step S104 will be described using the flowchart in Fig. 5. The flowchart in Fig. 5 is an example of the procedure for selecting a control pattern when the surrounding environment of the vehicle corresponds to a predetermined area in a specific region.

[0064] In step S141, it is determined whether the predicted collision position between the vehicle and the obstacle is in the vehicle's traveling direction based on the detection status of the obstacle recognized in step S101. In other words, it is determined whether there is an obstacle other than a four-wheeled vehicle whose predicted collision position is in the vehicle's traveling direction. If there is no obstacle whose predicted collision position is in the vehicle's traveling direction, the process proceeds to step S142, and if such an obstacle is present, the process proceeds to step S143.

[0065] In step S142, it is determined whether or not there is an obstacle crossing in front of the vehicle. If there is no obstacle other than a four-wheeled vehicle crossing in front of the vehicle, the process proceeds to step S151, where the control adjustment unit 24 selects the above-mentioned control pattern 1 as the control pattern for automatic braking control. The control adjustment unit 24 may select control pattern 2 as an alternative to control pattern 1. In this case, automatic braking control is executed by further treating pedestrians as target obstacles.

[0066] If it is determined in step S142 that there is an obstacle other than a four-wheeled vehicle crossing in front of the vehicle, the process proceeds to step S152, where the control adjustment unit 24 selects the above-mentioned control pattern 4 as the control pattern for the automatic brake control. In this case, the automatic brake control is executed with a bicycle crossing in front of the vehicle as the target obstacle.

[0067] In step S143, it is determined whether an obstacle whose predicted collision position is in the vehicle's traveling direction is crossing in front of the vehicle. If an obstacle is crossing in front of the vehicle, the process proceeds to step 153, where the control adjustment unit 24 selects the above-mentioned control pattern 5 as the control pattern for automatic brake control. In this case, automatic brake control is also executed for a motorcycle crossing in front of the vehicle. In control pattern 5, the threshold value of the predicted collision time TTC between the vehicle and the motorcycle used to determine the possibility of a collision is set to be smaller than the threshold value of the predicted collision time TTC between the vehicle and the motorcycle used to determine the possibility of a collision outside the specific area.

[0068] If it is determined in step S143 that an obstacle is not crossing in front of the vehicle, the process proceeds to step S144, where it is determined whether the predicted time to collision with the following vehicle TTCr is equal to or greater than the predetermined time Thr. If the predicted time to collision with the following vehicle TTCr is less than the predetermined time Thr, the process proceeds to step S154, where the control adjustment unit 24 selects the above-mentioned control pattern 3 as the control pattern for the automatic brake control. In this case, the automatic brake control is executed, further treating the pedestrian as the target obstacle.

[0069] If, in step S144, the predicted time to collision with the following vehicle TTCr is equal to or greater than the predetermined time Thr and there is substantially no possibility of a rear-end collision with the following vehicle, the process proceeds to step S155, where the control adjustment unit 24 selects the above-mentioned control pattern 6 as the control pattern for the automatic brake control. In this case, the automatic brake control is executed by further treating an animal as the target obstacle.

[0070] The vehicle control system 1 according to the present embodiment described above can achieve the following advantageous effects.

[0071] (1) The vehicle control system 1 includes a collision determination unit 21a that determines the possibility of a collision with a target obstacle present in front of the vehicle, a brake control unit 21b that controls the braking force to perform automatic brake control in accordance with the possibility of collision determined by the collision determination unit 21a, an environment recognition unit 22 that recognizes the environment around the vehicle, a situation recognition unit 23 that recognizes the detection status of obstacles around the vehicle, and a control adjustment unit 24 that changes the type of target obstacle in automatic brake control and the lower vehicle speed limit value for starting automatic brake control based on the environment around the vehicle recognized by the environment recognition unit 22 and the detection status recognized by the situation recognition unit 23.

[0072] The effectiveness and impact of implementing collision mitigation braking control may differ between an environment where multiple types of obstacles, such as four-wheeled vehicles, motorcycles, and pedestrians, are present around the vehicle and an environment where there are fewer obstacles around the vehicle. For example, in an environment where multiple types of obstacles are present, collision mitigation braking control may be implemented excessively, or implementing automatic braking control may result in the vehicle being rear-ended by a following vehicle. Furthermore, the effectiveness and impact of automatic braking control may differ depending on the conditions of the detected obstacles, such as the type of obstacle present around the vehicle, the relative position of the obstacle to the vehicle, and the direction and speed of movement of the obstacle relative to the vehicle. Therefore, by changing the type of obstacle targeted by automatic braking control and changing the vehicle speed lower limit for initiating automatic braking control depending on the vehicle's surrounding environment and the obstacle detection conditions, it is possible to implement appropriate automatic braking control according to the surrounding environment and the detection conditions.

[0073] (2) The control adjustment unit 24 sets a four-wheeled vehicle (a first type of obstacle) as a target obstacle in the specific area. The environment recognition unit 22 recognizes whether the environment around the vehicle is a predetermined area within the specific area. If the environment around the vehicle is a predetermined area within the specific area, the control adjustment unit 24 sets an obstacle other than a four-wheeled vehicle (a second type of obstacle) as a target obstacle in addition to the four-wheeled vehicle, and changes the vehicle speed lower limit. Here, the second type of obstacle includes, for example, at least one of a pedestrian, a bicycle, a motorcycle, and an animal. By changing the type of target obstacle depending on whether the environment around the vehicle is a predetermined area within the specific area, appropriate automatic brake control can be executed according to the surrounding environment.

[0074] (3) The environment recognition unit recognizes a predetermined area as being a predetermined area when the density of obstacles within a predetermined range around the vehicle is low. The first type of obstacle is a four-wheeled vehicle. The control adjustment unit 24 sets the vehicle speed lower limit for initiating automatic braking control for four-wheeled vehicles in a predetermined area within the specific area (e.g., suburban areas) to be lower than the vehicle speed lower limit for initiating automatic braking control for four-wheeled vehicles in areas other than the predetermined area within the specific area (e.g., urban areas) (control pattern 1). In specific areas where drivers tend to drive close to the vehicle in front or stop only after getting as close as possible to the vehicle in front in situations crowded with pedestrians, such as urban areas, if automatic braking control is performed with pedestrians as the target obstacle, the automatic braking control may be activated excessively or unnecessarily. Therefore, pedestrians are not included in the target obstacles outside the predetermined area, such as urban areas. On the other hand, in predetermined areas with few pedestrians and vehicles, such as suburban areas, including pedestrians as the target obstacles allows the collision damage mitigation brake to be activated while suppressing unnecessary activation of the automatic braking control. Incidentally, by including pedestrians as target obstacles in the predetermined area, it is expected that the vehicle in front will execute automatic braking control targeting the pedestrian, causing the vehicle speed of the vehicle in front to decrease. Therefore, by setting the vehicle speed lower limit for four-wheeled vehicles within the predetermined area lower than the vehicle speed lower limit outside the predetermined area, it is possible to start automatic braking control even at low speeds, which is expected to reduce the damage caused by a collision with a decelerating vehicle in front.

[0075] (4) The control adjustment unit 24 may set the vehicle speed lower limit for initiating automatic brake control for four-wheeled vehicles in a predetermined area (e.g., suburban areas) within the specific region to be higher than the vehicle speed lower limit for initiating automatic brake control for four-wheeled vehicles outside the specific region (control pattern 2). This makes it possible to prevent the automatic brake control from being activated excessively when the vehicle is traveling at low speed with a short distance to the vehicle ahead.

[0076] (5) The environment recognition unit 22 recognizes a predetermined area (e.g., suburban area) when the density of obstacles within a predetermined range around the vehicle is low. The situation recognition unit 23 recognizes at least one of the following as the obstacle detection status: the predicted collision position between the vehicle and the obstacle, the presence or absence of an obstacle crossing in front of the vehicle, and the predicted collision time TTCr between the vehicle and a following vehicle. The control adjustment unit 24 determines the type of obstacle to be targeted in automatic braking control and the lower vehicle speed limit value based on the obstacle detection status in a predetermined area within the specific region (control patterns 3 to 6). This makes it possible to reliably execute automatic braking control in situations where there is a high risk of collision with an obstacle while suppressing unnecessary operation of automatic braking control according to the obstacle detection status.

[0077] (6) The situation recognition unit 23 calculates the predicted collision position between the vehicle and a pedestrian as the obstacle detection situation. When the predicted collision position with a pedestrian is in the vehicle's direction of travel in a predetermined area within the specific region, the control adjustment unit 24 sets the pedestrian as a second type of obstacle different from a four-wheeled vehicle. The control adjustment unit 24 sets the vehicle speed lower limit (e.g., approximately 30 km / h) for initiating automatic braking control for a pedestrian in a predetermined area within the specific region higher than the vehicle speed lower limit (e.g., approximately 10 km / h) for initiating automatic braking control for a pedestrian outside the specific region (control pattern 3). In predetermined areas with few pedestrians and vehicles, such as suburban areas, high-risk collision situations where the predicted collision position between the vehicle and a pedestrian is in the vehicle's direction of travel are unlikely to occur. In such situations, it is assumed that the driver is not intentionally approaching the pedestrian at a low speed, but rather is driving at a relatively high speed while overlooking the pedestrian. Therefore, by setting the lower limit of the vehicle speed at which the automatic brake control is initiated to a relatively large value, unnecessary operation can be suppressed and the automatic brake control can be operated safely.

[0078] (7) The situation recognition unit 23 recognizes the presence or absence of a bicycle crossing in front of the vehicle as an obstacle detection situation. When a bicycle crosses in front of the vehicle in a predetermined area within the specific region, the control adjustment unit 24 sets the bicycle as a second type of obstacle different from a four-wheeled vehicle. The control adjustment unit 24 sets the lower vehicle speed limit (e.g., approximately 30 km / h) for initiating automatic braking control for a bicycle in a predetermined area within the specific region higher than the lower vehicle speed limit (e.g., approximately 10 km / h) for initiating automatic braking control for a bicycle outside the specific region (control pattern 4). Bicycles may slip through vehicles or suddenly enter and exit the roadway, resulting in an unfixed path, increasing the possibility of false detection and unnecessary activation of the automatic braking control. Therefore, bicycles are included as target obstacles only in high-risk situations where a bicycle crosses in front of the vehicle in a predetermined area within the specific region, and the lower vehicle speed limit for initiating automatic braking control is set to a relatively high value. This prevents unnecessary activation and enables safe activation of the automatic braking control.

[0079] (8) The situation recognition unit 23 recognizes the presence or absence of a motorcycle crossing in front of the vehicle as an obstacle detection situation, and if a motorcycle is present, further calculates a predicted collision position between the vehicle and the motorcycle. When the predicted collision position with the motorcycle is in the vehicle's direction of travel in a predetermined area within the specific region, the control adjustment unit 24 sets the motorcycle as a second type of obstacle different from four-wheeled vehicles. The control adjustment unit 24 sets a vehicle speed lower limit (e.g., approximately 30 km / h) for initiating automatic brake control for the motorcycle in a predetermined area within the specific region higher than a vehicle speed lower limit (e.g., approximately 10 km / h) for initiating automatic brake control for the motorcycle outside the specific region. The control adjustment unit 24 also sets a threshold for the predicted time to collision (TTC) between the vehicle and the motorcycle for determining the possibility of a collision in a predetermined area within the specific region lower than a threshold for the predicted time to collision (TTC) between the vehicle and the motorcycle for determining the possibility of a collision outside the specific region (control pattern 5). Motorcycles are faster than bicycles and often make sudden lane changes, such as passing through other vehicles, which increases the possibility of false detection and unnecessary activation of the automatic brake control. Therefore, motorcycles are included as target obstacles only in high-risk situations where the predicted collision position between a vehicle and a motorcycle is in the vehicle's direction of travel within a specified area of ​​a specific region, and the lower limit of the vehicle speed at which automatic brake control begins is set to a relatively large value. Furthermore, by changing the collision prediction time threshold to a small value and delaying the start timing of automatic brake control, unnecessary activation can be suppressed when targeting motorcycles, allowing automatic brake control to be operated safely.

[0080] (9) The situation recognition unit 23 calculates the predicted time to collision (TTCr) between the vehicle and a following vehicle as the obstacle detection status. When an animal is present ahead of the vehicle in a predetermined area within a specific region and the predicted time to collision (TTCr) with the following vehicle is equal to or greater than a predetermined time, the control adjustment unit 24 sets the animal as a second type of obstacle different from four-wheeled vehicles (control pattern 6). Animals include small, agile animals such as dogs and cats, as well as large, slow-moving animals such as cows and elephants. As such, animals vary in appearance and speed depending on the type, making them difficult to detect by the imaging device 10 and the obstacle detection device 11. However, if the predicted time to collision (TTCr) with the following vehicle is long and the possibility of a collision with the following vehicle is low, executing automatic braking control for the animal is unlikely to result in secondary damage such as a collision with the following vehicle. Therefore, executing automatic braking control for the animal can be expected to reduce collision damage. Furthermore, setting the lower vehicle speed limit for animals to a relatively small value allows automatic braking control to be executed safely.

[0081] -Variations- (1) In the above-described embodiment, the procedure for selecting a control pattern based on the obstacle detection status was described using the flowchart in FIG. 5. However, the procedure for selecting a control pattern is not limited to this, and various modifications are possible. For example, after determining whether or not there is an obstacle crossing in front of the vehicle in steps S142 and S143, it may be further configured to determine whether or not the predicted time TTCr for a collision with a following vehicle is equal to or longer than a predetermined time Thr. An example of selecting a control pattern taking into account the predicted time TTCr for a collision with a following vehicle will be described below.

[0082] For example, if it is determined in step S142 that there is no obstacle other than a four-wheeled vehicle crossing in front of the vehicle, the control pattern 1 or the control pattern 2 can be selected depending on whether the predicted time TTCr for a collision with a following vehicle is equal to or greater than a predetermined time Thr. Alternatively, the control pattern 1 or the control pattern 2 can be selected when the predicted time TTCr for a collision with a following vehicle is less than the predetermined time Thr, and a control pattern different from the control patterns 1 and 2 can be selected when the predicted time TTCr for a collision is equal to or greater than the predetermined time Thr. In this case, for example, the reference pattern can be selected.

[0083] After it is determined in step S142 that there is an obstacle other than a four-wheeled vehicle crossing in front of the vehicle, control pattern 4 may be selected if the predicted time to collision with the following vehicle TTCr is equal to or greater than a predetermined time Thr, and a control pattern other than control pattern 4 may be selected if the predicted time to collision TTCr is less than the predetermined time Thr. By selecting control pattern 4, which treats a bicycle as the target obstacle, when there is virtually no possibility of a rear-end collision with a following vehicle, it is possible to safely activate automatic brake control while suppressing unnecessary activation. If the predicted time to collision TTCr is less than the predetermined time Thr, for example, the reference pattern may be selected.

[0084] After it is determined in step S143 that there is an obstacle other than a four-wheeled vehicle crossing in front of the vehicle, control pattern 5 may be selected if the collision prediction time TTCr with the following vehicle is equal to or greater than a predetermined time Thr, and a control pattern other than control pattern 5 may be selected if the collision prediction time TTCr is less than the predetermined time Thr. By selecting control pattern 5, which treats a motorcycle as the target obstacle, when there is virtually no possibility of a rear-end collision with a following vehicle, it is possible to safely operate automatic brake control while suppressing unnecessary operation. If the collision prediction time TTCr is less than the predetermined time Thr, for example, the reference pattern may be selected.

[0085] (2) In addition, in step S142, the type of obstacle crossing in front of the vehicle may also be determined, and if there is a bicycle crossing in front of the vehicle, the process may proceed to step S152. Similarly, in step S143, the type of obstacle crossing in front of the vehicle may also be determined, and if there is a motorcycle crossing in front of the vehicle, the process may proceed to step S153.

[0086] (3) In the above-described embodiment, the predicted collision position between the vehicle and an obstacle is taken into consideration when selecting control pattern 3 and when selecting control pattern 5. However, this is not limiting, and the predicted collision position between the vehicle and an obstacle may also be taken into consideration when selecting control pattern 4 and control pattern 6. For example, when the predicted collision position between the vehicle and a bicycle is in the vehicle's traveling direction, control pattern 4 can be selected. For example, when the predicted collision position between the vehicle and an animal is in the vehicle's traveling direction, control pattern 6 can be selected.

[0087] (4) The situation recognition unit 23 may be configured to detect the status of the obstacle detection system as the obstacle detection status. For example, the obstacle detection status may be detected as a malfunction of the imaging device 10 and the obstacle detection device 11 for detecting obstacles. For example, in a situation where the imaging device 10 cannot detect an obstacle due to a malfunction, automatic braking control may be performed based on information about the obstacle detected only by the obstacle detection device 11. The obstacle detection device 11, for example, a millimeter-wave radar, is configured to receive reflected waves from obstacles. However, because pedestrians do not receive the same reflection intensity as vehicles, the accuracy of pedestrian detection by the millimeter-wave radar decreases. Therefore, in such a case, appropriate automatic braking control according to the obstacle detection status can be performed by adjusting the content of the automatic braking control so that the target obstacles are limited to four-wheeled vehicles, for example.

[0088] (5) The vehicle may further include a surrounding environment acquisition device that acquires environmental information about the vehicle's surroundings, and the environment recognition unit 22 may recognize whether the vehicle's surroundings are a predetermined area within a specific region based on the information input from the surrounding environment acquisition device. For example, the surrounding environment acquisition device may include a detection means for detecting the weather, temperature, brightness, and / or time around the vehicle. The surrounding environment acquisition device may further include a detection means for detecting information about the road surface on which the vehicle is traveling. The environment recognition unit 22 may estimate whether the area around the vehicle is crowded with pedestrians or the like based on the environmental information about the vehicle's surroundings input from the surrounding environment acquisition device, and determine whether the vehicle's surroundings are a predetermined area within a specific region, based on the viewpoints that there are more people and traffic during the day than at night, more people and traffic on sunny days than on rainy days, more people and traffic in warm seasons than on cold seasons, and more people and traffic on clear roads than on icy roads.

[0089] The environment recognition unit 22 may be configured to determine whether the vehicle's surroundings are a predetermined area within a specific area by combining the environmental information about the vehicle's surroundings input from the surrounding environment acquisition device with the above-described method for determining a predetermined area within a specific area. For example, even if a geographical area is classified as a suburb, if a large event is scheduled to be held in that area at a certain time of year (season), it is estimated that the area will be crowded with pedestrians, etc., and therefore, if the vehicle is in that area at that time, it may be determined that the vehicle's surroundings are not a predetermined area. Furthermore, the environment recognition unit 22 may determine that the vehicle's surroundings are a predetermined area even in an urban area, from the viewpoint that drivers are expected to drive more carefully at night than during the day, or when the road surface is icy than when it is not icy.

[0090] (6) In the above-described embodiment, the situation recognition unit 23 is configured to recognize the predicted collision position between the vehicle and the obstacle, the presence or absence of an obstacle crossing in front of the vehicle, and the predicted collision time TTCr between the vehicle and a following vehicle as the obstacle detection situation. However, without being limited to this, the situation recognition unit 23 may be configured to recognize detailed obstacle movement situations, such as whether the obstacle is stationary, whether the obstacle is moving toward the vehicle, or whether the obstacle jumps out or cuts in, as the obstacle detection situation, and select a control pattern based on the recognition results.

[0091] (7) In the above-described embodiment, the adjustment function of the control content of the collision mitigation braking control is switched between enabled and disabled by operating the operation input device 15. However, this is not limited to this, and the adjustment function of the control content of the collision mitigation braking control may be configured to be enabled regardless of operating the operation input device 15. In this case, for example, it is possible to determine at a predetermined period whether the current position of the vehicle is within a predetermined area in a specific region, and when it is determined that the current position of the vehicle is within the predetermined area in the specific region, the adjustment function of the control content of the collision mitigation braking control can be automatically enabled.

[0092] Although several embodiments of the present invention have been described above, it should be noted that the present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the present invention. [Explanation of symbols]

[0093] 1 Vehicle control system 10. Imaging device 11 Obstacle detection device 12 Vehicle speed sensor 13 Positioning equipment 14 Map Information Database 20 Control device 21 AEB control unit, 21a collision determination unit, 21b brake control unit 22 Environmental Awareness Department 23 Situational Awareness Department 24 Control adjustment section 30 Brake device

Claims

1. a collision determination unit that determines the possibility of a collision with a target obstacle present in front of the vehicle; a brake control unit that controls a braking force so as to perform automatic brake control in accordance with the possibility of a collision determined by the collision determination unit; an environment recognition unit that recognizes the surrounding environment of the vehicle; a situation recognition unit that recognizes a detection situation of an obstacle around the vehicle; a control adjustment unit that changes the type of the target obstacle in the automatic brake control and a vehicle speed lower limit value for starting the automatic brake control based on the surrounding environment of the vehicle recognized by the environment recognition unit and the detection situation recognized by the situation recognition unit; and A vehicle control system comprising:

2. the control adjustment unit sets a first type of obstacle as the target obstacle in the specific area; the environment recognition unit recognizes whether the surrounding environment of the vehicle is a predetermined area within the specific region; 2. The vehicle control system according to claim 1, wherein when the surrounding environment of the vehicle is the predetermined area within the specific region, the control adjustment unit sets, in addition to the first type of obstacle, a second type of obstacle different from the first type of obstacle as the target obstacle, and changes the vehicle speed lower limit value.

3. the environment recognition unit recognizes the predetermined area as being the predetermined region when a density of obstacles within a predetermined range around the vehicle is low; the first type of obstacle is a four-wheeled vehicle; 3. The vehicle control system according to claim 2, wherein the control adjustment unit sets the vehicle speed lower limit value for initiating the automatic brake control for the four-wheeled vehicle in the predetermined area within the specific region to be smaller than the vehicle speed lower limit value for initiating the automatic brake control for the four-wheeled vehicle in a region other than the predetermined area within the specific region.

4. 4. The vehicle control system according to claim 3, wherein the control adjustment unit sets the vehicle speed lower limit value for initiating the automatic brake control for the four-wheeled vehicle in the predetermined area within the specific region to be greater than the vehicle speed lower limit value for initiating the automatic brake control for the four-wheeled vehicle outside the specific region.

5. the environment recognition unit recognizes the predetermined area as being the predetermined region when a density of obstacles within a predetermined range around the vehicle is low; the situation recognition unit recognizes, as the obstacle detection situation, at least one of a predicted collision position between the vehicle and the obstacle, whether or not there is an obstacle crossing in front of the vehicle, and a predicted collision time between the vehicle and a following vehicle; 3. The vehicle control system according to claim 2, wherein the control adjustment unit determines the type of the target obstacle and the lower vehicle speed limit value for the automatic brake control based on the detection status of the obstacle in the predetermined area within the specific region.

6. the environment recognition unit recognizes the predetermined area as being the predetermined region when a density of obstacles within a predetermined range around the vehicle is low; the first type of obstacle is a four-wheeled vehicle; the situation recognition unit calculates a predicted collision position between the vehicle and the pedestrian as the obstacle detection situation; the control adjustment unit sets the pedestrian as the second type of obstacle when a predicted collision position with the pedestrian is in a traveling direction of the vehicle in the predetermined area within the specific region; 3. The vehicle control system according to claim 2, wherein the control adjustment unit sets the vehicle speed lower limit value for initiating the automatic brake control for the pedestrian in the predetermined area within the specific region to be greater than the vehicle speed lower limit value for initiating the automatic brake control for the pedestrian outside the specific region.

7. the environment recognition unit recognizes the predetermined area as being the predetermined region when a density of obstacles within a predetermined range around the vehicle is low; the first type of obstacle is a four-wheeled vehicle; the situation recognition unit recognizes the presence or absence of a bicycle crossing in front of the vehicle as the obstacle detection situation, the control adjustment unit, when a bicycle crossing in front of the vehicle is present in the predetermined area within the specific region, sets the bicycle as the second type of obstacle; 3. The vehicle control system of claim 2, wherein the control adjustment unit sets the vehicle speed lower limit value for initiating the automatic brake control for the bicycle in the specified area within the specific region to be greater than the vehicle speed lower limit value for initiating the automatic brake control for the bicycle outside the specific region.

8. the environment recognition unit recognizes the predetermined area as being the predetermined region when a density of obstacles within a predetermined range around the vehicle is low; the first type of obstacle is a four-wheeled vehicle; the situation recognition unit recognizes the presence or absence of a motorcycle crossing in front of the vehicle as the obstacle detection situation, and if the motorcycle is present, further calculates a predicted collision position between the vehicle and the motorcycle; the control adjustment unit sets the motorcycle as the second type of obstacle when a predicted position of collision with the motorcycle is in a traveling direction of the vehicle in the predetermined area within the specific region; the control adjustment unit sets the vehicle speed lower limit value for initiating the automatic brake control for the motorcycle in the predetermined area within the specific region to be larger than the vehicle speed lower limit value for initiating the automatic brake control for the motorcycle outside the specific region; 3. The vehicle control system according to claim 2, wherein the control adjustment unit sets a threshold value of a collision prediction time between the vehicle and the motorcycle for determining the possibility of a collision in the predetermined area within the specific region to be smaller than a threshold value of a collision prediction time between the vehicle and the motorcycle for determining the possibility of a collision outside the specific region.

9. the environment recognition unit recognizes the predetermined area as being the predetermined region when a density of obstacles within a predetermined range around the vehicle is low; the first type of obstacle is a four-wheeled vehicle; 9. The vehicle control system according to claim 5, wherein the control adjustment unit sets the vehicle speed lower limit value for initiating the automatic brake control for the four-wheeled vehicle in the predetermined area within the specific region to be smaller than the vehicle speed lower limit value for initiating the automatic brake control for the four-wheeled vehicle in a region other than the predetermined area within the specific region.

10. the environment recognition unit recognizes the predetermined area as being the predetermined region when a density of obstacles within a predetermined range around the vehicle is low; the first type of obstacle is a four-wheeled vehicle; the situation recognition unit calculates a predicted time of collision between the vehicle and a following vehicle as the obstacle detection situation, 3. The vehicle control system of claim 2, wherein the control adjustment unit sets the animal as the second type of obstacle when an animal is present in front of the vehicle in the specified area within the specific region and the predicted time of collision with the following vehicle is equal to or longer than a specified time.

Images