JP2005138623A - Vehicle travel support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving support device for a vehicle, and to provide driving support for a driver in a timely manner according to an actual road condition.
A steering avoidance distance Xb capable of avoiding a collision of an own vehicle with an obstacle by steering and a braking avoidance distance Xa capable of avoiding a collision of the own vehicle with an obstacle by braking are calculated. When the actual distance Lf from the host vehicle to the obstacle is shorter than the steering avoidance distance Xb and shorter than the braking avoidance distance Xa, driving assistance to the driver by automatic braking or warning of the vehicle is performed. In calculating the steering avoidance distance Xb, road boundary information such as guardrail stored in the map database is taken into consideration. For example, when a vehicle travels on a road with a guardrail or the like installed on one side, the steering avoidance distance Xb by steering to the opposite side is calculated as the steering avoidance distance Xb of the vehicle on the assumption that steering to the guardrail side is impossible To do.
[Selection] Figure 3

Description

  The present invention relates to a vehicle travel support device, and in particular, a vehicle that calculates a distance to an obstacle that can avoid a collision of an own vehicle with an obstacle by steering and performs driving support for a driver based on the calculation result. The present invention relates to a travel support device.

2. Description of the Related Art Conventionally, there has been known a device that operates an automatic brake on a host vehicle when the distance between the host vehicle and an obstacle is equal to or less than a predetermined distance (see, for example, Patent Document 1). This device first calculates a first collision avoidable distance by which a collision of an own vehicle with an obstacle can be avoided by braking, and calculates a second collision avoidable distance by which the collision can be avoided by steering. Then, the automatic brake is activated when the actual distance between the host vehicle and the obstacle is equal to or less than the first collision avoidable distance and the second collision avoidable distance calculated as described above. Therefore, according to the above-described device, the automatic brake is activated when the collision cannot be avoided by either steering or braking. Therefore, while respecting the driver's intention to drive, It is possible to effectively reduce the impact.
JP-A-6-298022

  By the way, in the above-described conventional apparatus, the calculation of the second collision avoidance distance by steering is performed based on the motion performance of the vehicle such as the speed of the host vehicle and the relative speed with the obstacle. That is, the distance is calculated by calculating the conditions of the road on which the vehicle is traveling, specifically, the presence of guard races, median strips, side grooves, oncoming vehicles, and following vehicles, and the presence of cliffs and side walls. Is not considered. For this reason, for example, even when a vehicle travels on a road on which a guardrail is installed on the left side of the road, the second collision avoidance distance by left steering calculated from the motion performance of the vehicle is used as a control threshold, and automatic braking is performed. Will be involved in the operation. That is, for example, even in a situation where vehicle collision avoidance cannot actually be realized by left steering, the actual distance between the host vehicle and the obstacle is determined by left steering. The automatic brake will not operate unless the distance is equal to or shorter than the second collision avoidance distance. In this regard, in the above-described conventional apparatus, it has been difficult to say that driving assistance to the driver is performed in a timely manner in accordance with road conditions.

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide a vehicle travel support device that can perform driving support for a driver in a timely manner in accordance with actual road conditions.

  The object is to provide a steering avoidance distance calculating means for calculating a first collision avoidance distance to an obstacle capable of avoiding a collision of the own vehicle with an obstacle by steering, and the steering avoidance as described in claim 1 A vehicle driving support device comprising a warning means for the driver or a control means for automatically controlling the vehicle based on the calculation result of the distance calculation means, wherein the steering avoidance distance calculation means is a condition of a road on which the host vehicle is running This is achieved by the vehicle travel support device that calculates the first collision avoidance distance in consideration of the above.

  In the present invention, the first collision avoidance distance to an obstacle capable of avoiding a collision with an obstacle of the own vehicle by steering is used for alarming the driver or automatic control of the vehicle. It is calculated in consideration of the road conditions. In such a configuration, if it is difficult to avoid collision by steering, control such as warning is executed based on the collision avoidance distance calculated in consideration of the situation. It will be performed in a timely manner according to the situation.

  In this case, as described in claim 2, in the vehicle travel support device according to claim 1, the information indicating the road condition includes a region where the vehicle that can affect steering avoidance of the vehicle and a region where the vehicle cannot travel And the information of the road boundary that divides

  According to a third aspect of the present invention, in the vehicle travel support device according to the first aspect, the information indicating the road condition may be obtained from a road map database storing map information.

  Furthermore, as described in claim 4, in the vehicle travel support device according to claim 1, the information indicating the road condition may be obtained from a beacon embedded in the road.

  According to a fifth aspect of the present invention, in the vehicle travel support device according to the first aspect, the steering avoidance distance calculating means can avoid a collision by left steering in consideration of the situation on the left side of the road on which the host vehicle is traveling. Left steering calculation means for calculating the left steering collision avoidance distance to the obstacle, and right steering collision avoidance to the obstacle that can be avoided by right steering in consideration of the situation on the right side of the road on which the host vehicle is traveling A right-steering calculation means for calculating a distance. When at least one of collision avoidance by left steering and collision avoidance by right steering is in a difficult situation, the calculation is performed in consideration of the situation. Since control such as an alarm is executed based on the collision avoidance distance, driving assistance to the driver is performed with good timing according to road conditions.

  According to a sixth aspect of the present invention, in the vehicle travel support device according to the first aspect, the road condition includes a road width, and the steering avoidance distance calculating means is configured to prevent the vehicle from colliding with an obstacle while If the first collision avoidance distance is calculated within a range that falls within the width, the driving assistance to the driver is performed with good timing in accordance with the road width that the vehicle can avoid the collision.

  Furthermore, as described in claim 7, in the vehicle travel support device according to claim 1, braking avoidance distance calculation for calculating a second distance to the obstacle capable of avoiding a collision of the host vehicle with the obstacle by braking. If the control means performs warning for the driver or automatic vehicle control based on the calculation result of the steering avoidance distance calculation means and the calculation result of the braking avoidance distance calculation means, In a situation where collision avoidance is impossible, control such as a warning is executed based on the distance at which collision can be avoided by braking, so that driving assistance to the driver is performed in a timely manner in accordance with road conditions.

  In this case, as described in claim 8, in the vehicle travel support device according to claim 7, the control unit is configured such that the actual distance from the host vehicle to the obstacle is calculated by the steering avoidance distance calculation unit. If the vehicle is automatically braked when it is shorter than the second distance and shorter than the second distance calculated by the braking avoidance distance calculating means, the driving assistance to the driver It is done in a timely manner according to the road conditions while respecting.

  According to the first to fifth aspects of the present invention, driving support to the driver by control such as an alarm can be started with good timing according to the road condition.

  According to the sixth aspect of the present invention, driving assistance to the driver by control such as an alarm can be started with good timing in accordance with the width of the road where the vehicle can avoid a collision.

  According to the seventh aspect of the present invention, in the situation where collision avoidance by steering is impossible, control such as warning is executed based on the distance where collision can be avoided by braking. You can start in a timely manner according to the situation.

  According to the eighth aspect of the present invention, driving support to the driver by control such as an alarm can be started in a timely manner in accordance with road conditions while respecting the driver's intention to drive.

  FIG. 1 is a configuration diagram of a system according to an embodiment of the present invention. The system of the present embodiment includes a vehicle travel support apparatus 10 that is mounted on a vehicle and supports vehicle travel. The vehicle travel support device 10 includes an electronic control unit (hereinafter referred to as a main ECU) 12 constituted by a microcomputer or the like, and is controlled by the main ECU 12.

  The vehicle travel support device 10 includes a camera 14 and a vehicle state sensor 16. The camera 14 is disposed, for example, in a vehicle front bumper or a vehicle interior room mirror stay, and captures a predetermined area extending in front of the vehicle from the disposed portion. The vehicle state sensor 16 outputs a signal corresponding to the vehicle state such as the speed and acceleration of the vehicle. Both the image captured by the camera 14 and the output signal of the vehicle state sensor 16 are supplied to the image processing ECU 18. The image processing ECU 18 processes the image supplied from the camera 14, thereby recognizing an object such as a pedestrian or a car projected on the image, a white line or a guardrail that demarcates a travel lane in which the vehicle travels. And the position with respect to vehicles, such as the recognized object and a white line, and the width | variety of a driving | running lane or a road are detected.

  The image processing ECU 18 is connected to the main ECU 12 described above. Information detected by the image processing ECU 18 is supplied to the main ECU 12. Based on the information supplied from the image processing ECU 18, the main ECU 12 detects the position of an object, a white line, or the like existing in front of the vehicle, and also detects the travel lane and the width of the road.

  The main ECU 12 is connected to the vehicle state sensor 16 described above, and is also connected to a radar 20 disposed on a bumper or the like at the front of the vehicle body. The radar 20 has a function of receiving a reflected wave reflected on a front obstacle such as a pedestrian, a car, or a motorcycle by radiating a radio wave having, for example, a millimeter wave toward a predetermined range in front of the vehicle. A signal corresponding to the presence / absence of the front obstacle, the distance Lf to the front obstacle and the relative velocity is generated from the reflected wave. The main ECU 12 detects the vehicle state such as speed and acceleration based on the output signal of the vehicle state sensor 16. Further, the main ECU 12 detects a distance Lf and a relative speed with respect to a front obstacle existing in front of the vehicle based on a signal supplied from the radar 20.

  A navigation device 22 is also connected to the main ECU 12. The navigation device 22 has a map database 24 composed of DVD, CD, hard disk or the like. In this map database 24, map information of the position (latitude, longitude, etc.) of each point on the road on which the vehicle travels is stored, and further, boundary information on the road on which the vehicle travels, specifically, Road width information, and the road boundaries such as guardrails, median strips, gutters, cliffs, and sidewalls that divide the areas where vehicles can travel and areas that cannot travel on the left and right sides of the road are within the specified distance from the driving lane. Road boundary presence / absence information indicating whether or not it exists is stored together with absolute position information of the boundary. The map database 24 need not be mounted on the vehicle, but may be mounted on a center capable of wireless communication with the vehicle and provide the vehicle with map information stored therein at a predetermined timing.

  The navigation device 22 includes a GPS receiver that receives a signal (GPS data) from a GPS (Global Positioning System) satellite, and a signal (INS (Inertial Navigation Sensor) data corresponding to the traveling direction of the yaw, roll, pitch, etc.) of the vehicle. ) To output a gyro sensor. The navigation device 22 measures the current position (specifically, latitude, longitude, altitude) of the host vehicle based on the GPS data received by the GPS receiver, and based on the INS data output from the gyro sensor. The traveling direction is detected, and the detected current position data and the traveling direction data are merged to detect an accurate current position of the host vehicle. Then, the detected current position of the vehicle is displayed in accordance with a designated scale, if necessary, in the surrounding road map read from the map database 24 in the navigation mode of the display monitor provided in the passenger compartment. When displaying on the monitor, it is displayed superimposed on the road map on the image.

  The road boundary presence / absence information stored in the map database 24 described above may be provided every several meters or several tens of meters on the road, for example, but ends at the start point where the road boundary starts to exist at the intersection unit. It may be provided only at the end point, and is different for each traveling direction of the vehicle even on the same road. Information stored in the map database 24 is read by a command from the navigation device 22. As will be described in detail later, the main ECU 12 requests the navigation device 22 to read road boundary presence / absence information from the map database 24 and output the information in a predetermined case. The main ECU 12 receives the information read and output from the map database 24, and executes a process for supporting the running of the vehicle as described later according to the received information.

  Further, a braking force control device 30 and an alarm device 32 are connected to the main ECU 12. The braking force control device 30 has a brake actuator that brakes the vehicle. The alarm device 32 is provided in the vehicle interior and has a speaker and a display that provide predetermined information audibly or visually to the vehicle driver or call out predetermined attention. The main ECU 12 supplies a command for braking the vehicle to the braking force control device 30 according to a method described later, or supplies a command for prompting the vehicle driver to perform a braking operation or steering operation to the vehicle driver. . The braking force control device 30 generates a braking force for automatically braking the vehicle using a brake actuator in accordance with a command supplied from the main ECU 12. Further, the warning device 32 issues a warning that prompts the vehicle driver to perform a braking operation or a steering operation using a speaker or a display in accordance with a command supplied from the main ECU 12.

  Next, operation | movement of the vehicle travel assistance apparatus 10 of a present Example is demonstrated.

  FIG. 2 shows that there is a stationary obstacle in front of the vehicle, and the minimum distance to the obstacle (hereinafter referred to as a braking avoidance distance) Xa at which the vehicle can avoid a collision with the obstacle by braking, The figure showing the relationship with the minimum distance (henceforth a steering avoidance distance) Xb to the obstacle which can avoid the collision with an obstacle by steering is shown. In FIG. 2, the horizontal axis represents the vehicle speed, and the vertical axis represents the distance from the braking start position or the steering start position.

  As shown in FIG. 2, the above-described braking avoidance distance Xa increases in a substantially quadratic curve as the vehicle speed increases from the vehicle performance, and the steering avoidance distance Xb increases between the geometry of the vehicle and the obstacle. From the general relationship, it increases almost linearly as the vehicle speed increases. At this time, in a region where the vehicle speed is smaller than the predetermined value (region on the left side of the dotted line in FIG. 2), the steering avoidance distance Xb is longer than the braking avoidance distance Xa, while the vehicle speed is larger than the predetermined value (FIG. 2). In the region on the right side of the dotted line in FIG. 2), the steering avoidance distance Xb is shorter than the braking avoidance distance Xa.

  In this regard, whenever the actual distance Lf between the host vehicle and the obstacle falls below the steering avoidance distance Xb in an area where the vehicle speed is relatively low, automatic braking by the braking force control device 30 and warning by the warning device 32 are executed. If the actual distance Lf is not less than the braking avoidance distance Xa, that is, even if the collision can be avoided by the driver's braking operation, the automatic brake is activated or a warning is issued. Can occur. Similarly, when the actual distance Lf between the host vehicle and the obstacle falls below the braking avoidance distance Xa in a relatively high vehicle speed region, an automatic brake by the braking force control device 30 and an alarm by the warning device 32 are executed. If the actual distance Lf is not less than the steering avoidance distance Xb, that is, even if the collision can be avoided by the driver's steering operation, the automatic brake is activated or a warning is issued. Can occur. For this reason, in such a control method, an automatic brake and a warning are activated at a timing unexpected by the driver, the driver's intention to drive is obstructed, and driving feeling is deteriorated.

  Therefore, in the vehicle travel support device 10 of the present embodiment, first, the above-described braking avoidance distance Xa due to vehicle braking is calculated based on the detected own vehicle speed and acceleration and the relative speed with the front obstacle, The above-described steering avoidance distance Xb by vehicle steering is calculated. Note that the calculation of the steering avoidance distance Xb is performed in consideration of the relative positional relationship between the host vehicle and the obstacle, and is performed for each of the left steering and the right steering. The smaller one of the steering avoidance distance Xb by the left steering and the steering avoidance distance Xb by the right steering is used for driving assistance control by automatic braking and warning as described below.

  Next, it is determined whether or not the detected actual distance Lf to the front obstacle is shorter than the braking avoidance distance Xa calculated as described above and shorter than the steering avoidance distance Xb calculated as described above. The When the actual distance Lf is equal to or greater than the braking avoidance distance Xa or the steering avoidance distance Xb, automatic braking or warning is not performed. On the other hand, when the actual distance Lf is shorter than the braking avoidance distance Xa and shorter than the steering avoidance distance Xb, an automatic brake by the braking force control device 30 and an alarm by the alarm device 32 are executed.

  Therefore, according to the vehicle travel support device 10 of the present embodiment, in a situation where a collision with an obstacle can be avoided by a driver's braking operation or steering operation, an automatic brake or an alarm does not operate, and driving Since the automatic brake and alarm are activated only when the driver can not avoid a collision with an obstacle by either the braking operation or the steering operation, the driver feels to respect the driver's driving intention as much as possible. It is possible to effectively relieve the impact caused by the collision between the host vehicle and the obstacle while maintaining the above.

  FIG. 3 is a diagram for explaining the timing for starting driving support to the driver by automatic braking or warning in the vehicle travel support device 10 of the present embodiment. 3A shows a case where driving assistance according to the method of this embodiment is not performed, and FIGS. 3B and 3C show a case where driving assistance according to the method of this embodiment is performed. , Respectively.

  By the way, on the actual road on which the vehicle travels, due to the presence of guardrails, median strips, gutters, cliffs, side walls, oncoming vehicles, subsequent vehicles, etc. A region where traveling is physically impossible is formed. In such a road situation, when the vehicle speed is relatively small, the steering avoidance distance Xb is larger than the braking avoidance distance Xa. Therefore, the road situation hardly affects the driving support control by the automatic brake or warning described above. Since the steering avoidance distance Xb is smaller than the braking avoidance distance Xa when the vehicle speed is relatively high, the road condition greatly affects the driving support control.

  That is, for example, when a guardrail is installed on the left side of the road as shown in FIG. 3 and the vehicle cannot realize collision avoidance with an obstacle by left steering, Assuming that the left steering functions effectively, as shown in FIG. 3 (A), the automatic brake or alarm does not operate until the actual distance Lf from the vehicle to the obstacle is equal to or less than the steering avoidance distance Xb by the left steering. Then, appropriate driving assistance is not performed, and an unexpected situation may occur.

  Therefore, in the vehicle travel support device 10 of the present embodiment, when calculating the steering avoidance distance Xb in order to perform driving support by automatic braking or warning due to the presence of an obstacle at an appropriate timing, a guardrail, an oncoming vehicle, etc. It is characterized in that the actual road conditions on which the vehicle travels are taken into consideration. Hereinafter, the characteristic part of a present Example is demonstrated.

  Specifically, in this embodiment, first, whether or not a road boundary such as a guardrail exists on a road between a predetermined distance from the current position of the host vehicle detected by using the navigation device 22 to the vehicle traveling direction side. Is determined based on the road boundary presence / absence information stored in the map database 24. If there is no road boundary, it is possible to run even if the vehicle is steered, and no unexpected situation will occur, but if there is a road boundary, it will become impossible to run when the vehicle steers, An unexpected situation will occur.

  Therefore, when it is determined that there is no road boundary, the steering avoidance distance Xb by vehicle steering is calculated for each of left steering and right steering as usual. The smaller one of the steering avoidance distance by left steering and the steering avoidance distance by right steering is used as a control threshold value for driving assistance control by automatic braking or warning. On the other hand, when it is determined that a road boundary exists, calculation of the steering avoidance distance Xb by vehicle steering is performed assuming that steering to the side where the road boundary exists is impossible. For example, when a road boundary such as a guardrail exists only on the left side of the road, it is assumed that left steering avoidance is impossible, and only the steering avoidance distance Xb by right steering is calculated, and the steering avoidance distance Xb by left steering is calculated. Is used as a control threshold value for driving support control. For example, when there are road boundaries such as guard rails on both sides of the road, it is assumed that both left and right steering are impossible, that is, the calculation result of the steering avoidance distance Xb is infinite. Support control is executed.

  In such a configuration, in a situation where the vehicle travels at a relatively high speed, for example, when a guardrail or the like exists only on the left side of the road, the actual distance Lf from the host vehicle to the obstacle is determined by right steering as shown in FIG. If it is less than the steering avoidance distance Xb, driving assistance by automatic braking or warning is realized. Further, in a situation where the vehicle travels at a relatively high speed, for example, when guardrails or the like are present on both sides of the road, as shown in FIG. 3C, the actual distance Lf from the host vehicle to the obstacle is the braking avoidance distance Xa due to braking. If it falls below, driving assistance by automatic braking and warning is realized.

  That is, in the vehicle travel support device 10 of the present embodiment, when there is a boundary such as a guardrail that makes it impossible for the vehicle to travel on the left side or the right side of the road during high speed travel, the actual distance to the obstacle is the road condition. Even if it does not fall below the steering avoidance distance Xb calculated as usual, which is not considered, automatic braking and warning are started before that. In this case, an action for avoiding a collision with an obstacle early is realized in response to a situation where steering avoidance is impossible, and the collision avoidance action is prevented from being too late. Therefore, according to the vehicle travel support device 10 of the present embodiment, the road situation by the road boundary that divides the road travelable area and the road unusable area in the driving assistance by the automatic brake or warning caused by the presence of the obstacle. It is possible to start and execute with good timing.

  FIG. 4 shows a flowchart of an example of a control routine executed by the main ECU 12 in the vehicle travel support apparatus 10 of the present embodiment in order to realize the above function. The routine shown in FIG. 4 is a routine that is repeatedly activated every predetermined time. When the routine shown in FIG. 4 is started, first, the process of step 100 is executed.

  In step 100, a process of reading the current position of the host vehicle and road boundary presence / absence information from the navigation device 22 and reading the image processing result of the image captured by the camera 14 from the image processing ECU 18 is executed. In step 102, a process of measuring a front obstacle existing in front of the host vehicle based on a signal from the radar 20, specifically, a longitudinal distance Lf from the host vehicle to the front obstacle and a relative position in the vehicle width direction. And the process which detects the relative speed of the own vehicle and a front obstacle is performed. In step 104, the vehicle state such as the speed and acceleration of the host vehicle is detected based on the output signal of the vehicle state sensor 16.

  In step 106, based on the own vehicle speed or acceleration detected in steps 102 and 104 and the relative speed with the front obstacle, the braking avoidance to the front obstacle that can avoid the collision of the own vehicle with the front obstacle by the braking. A distance Xa is calculated. In step 108, based on the vehicle speed or acceleration detected in steps 102 and 104, the relative speed with the front obstacle, and the vehicle width direction positional relationship between the host vehicle and the front obstacle, the front obstacle of the own vehicle is determined. A steering avoidance distance Xb to a front obstacle that can avoid a collision with an object by steering is calculated.

  In step 108, when calculating the steering avoidance distance Xb, the road boundary presence / absence information of the road on which the vehicle travels, which is read in step 100, is considered. Specifically, when a road boundary such as a guard rail does not exist within a predetermined distance in the vehicle width direction from the travel lane on the road in the vehicle traveling direction, the steering avoidance distance Xb by left steering and the steering avoidance distance Xb by right steering Both are calculated by geometric calculation based on the state of the vehicle, the relative speed to the obstacle and the position in the vehicle width direction. On the other hand, when a road boundary exists, steering to the road boundary side is impossible. As an example, the steering avoidance distance Xb in that direction is set to infinity, and the steering avoidance distance Xb by steering to the opposite side is geometric based on the state of the host vehicle, the relative speed with respect to the obstacle, and the position in the vehicle width direction. Calculated by calculation. When there are boundaries on both sides of the road, the steering avoidance distance Xb by left steering and the steering avoidance distance Xb by right steering are both set to infinity.

  In step 110, the actual distance Lf to the front obstacle detected in step 102 is shorter than the braking avoidance distance Xa calculated in step 106, and from the steering avoidance distance Xb calculated in step 108. Because of this short time, it is determined whether or not the collision between the host vehicle and the front obstacle cannot be avoided by both braking and steering. As a result, if a negative determination is made, it can be determined that the collision can be avoided by at least one of the braking operation and the steering operation of the vehicle driver, so the processing of step 112 is executed next. On the other hand, if an affirmative determination is made, it can be determined that the collision cannot be avoided while waiting for the braking operation and steering operation of the vehicle driver, so the process of step 114 is executed next.

  In step 112, processing for canceling driving assistance by automatic braking or warning, or processing for not performing such driving assistance is executed. Further, in step 114, a process for performing driving support by automatic braking or warning is executed. According to the above processing, the automatic brake and alarm can be activated only when the collision with the obstacle cannot be avoided by any of the driver's braking operation and steering operation. For this reason, it is possible to effectively mitigate the impact caused by the collision between the host vehicle and the obstacle while maintaining the driving feeling while respecting the driving intention of the driver as much as possible. When the process of step 112 or 114 is finished, the current routine is finished.

  According to the routine shown in FIG. 4, in a situation where collision avoidance by at least one of left steering and right steering becomes impossible during high speed traveling, the steering avoidance distance by the steering is substantially excluded, Driving assistance control by automatic braking or warning can be executed using the steering avoidance distance by steering to the opposite side or the braking avoidance distance by braking as a control threshold value. For this reason, driving assistance to the driver can be started with good timing according to the road boundary as the road condition. Therefore, according to the vehicle travel support device 10 of the present embodiment, the driving support to the driver by the automatic brake or warning due to the presence of the obstacle is timed according to the road condition while respecting the driver's driving intention. It is possible to start and execute well.

  In the above embodiment, the steering avoidance distance Xb is the “first collision avoidance distance” described in the claims, and the braking avoidance distance Xa is the “second collision avoidance distance” described in the claims. ”And the main ECU 12 executes the processing of step 108 in the routine shown in FIG. 4 to thereby execute“ steering avoidance distance calculating means ”and“ left steering calculation ”described in the claims. The “braking avoidance distance calculating means” described in the claims is executed when the “means” and the “right steering calculating means” execute the process of step 106, and the claims are executed when the steps 112 and 114 are executed. The “control means” described in the above is realized.

  By the way, in the above-described embodiment, the presence / absence information of the road boundary that divides the area where the vehicle can travel and the area where the vehicle cannot travel is read from the map database 24, but the present invention is limited to this. Instead, it is possible to recognize a guardrail, a median strip, a gutter, and the like from an image captured by the camera 14 that captures the front of the vehicle, and obtain road boundary presence / absence information based on the recognition result. Similarly, for example, a beacon or a magnetic marker indicating that the road boundary exists and the road boundary ends is embedded in a road at a predetermined distance in front of the road boundary, and the beacon is detected by detecting the beacon when the vehicle passes. It is good also as obtaining the information on the presence or absence of a road boundary from the above.

  Further, in the above embodiment, the steering avoidance distance Xb is calculated in consideration of the road boundary due to guardrails, median strips, side grooves, cliffs, side walls, etc. stored as information in the map database 24. The present invention is not limited to this, and instead of the road boundary presence / absence information or together with the road boundary presence / absence information, the vehicle travels in the same direction as the own vehicle to the traveling lane adjacent to the traveling lane on which the own vehicle is traveling. The steering avoidance distance Xb may be calculated in consideration of whether there is an overtaking vehicle or an oncoming vehicle that travels in the opposite direction to the host vehicle. That is, when an overtaking vehicle, an oncoming vehicle, or the like actually exists in the adjacent lane, the steering avoidance distance Xb is calculated on the assumption that steering avoidance in that direction is impossible, and driving support control by automatic braking or warning is executed. Is done. Even in such a configuration, the actual avoidance of the road is calculated in consideration of the actual road condition. Therefore, an action to avoid a collision with an obstacle early in response to a situation in which the steering avoidance is impossible. Realized and driving assistance by automatic braking and warning due to the presence of obstacles will be started in a timely manner according to the actual road conditions.

  In this case, the presence / absence of an overtaking vehicle or an oncoming vehicle in an adjacent lane may be determined based on a captured image of a vehicle-mounted camera, a radar output, or a communication result by inter-vehicle communication. Further, at this time, the main ECU 12 calculates the steering avoidance distance Xb in consideration of the presence or absence of the following vehicle or the oncoming vehicle in the adjacent traveling lane, whereby the “steering avoidance distance calculating means” and the “left steering” are described. "Calculating means" and "Right steering calculating means" are realized.

  In the above embodiment, automatic braking is performed as automatic vehicle control when the actual distance between the host vehicle and the obstacle is less than the braking avoidance distance Xa and less than the steering avoidance distance Xb. The invention is not limited to this, and automatic steering may be performed during high-speed traveling. However, when it is determined that steering to the left side or the right side of the road is impossible according to the road boundary presence / absence information by a guardrail or a vehicle, it is appropriate not to perform automatic steering in that direction.

  Furthermore, in the above embodiment, when there is a boundary such as a guardrail that makes it impossible for the vehicle to travel on the left or right side of the road during high speed traveling, it is assumed that steering in that direction cannot be avoided, that is, The vehicle steering avoidance distance Xb is calculated assuming that the steering avoidance distance in the direction is infinite, but the present invention is not limited to this, and the road width in the vehicle width direction in which the vehicle can travel ( That is, the distance between the boundary on the left side of the road and the boundary on the right side of the road may be considered.

  FIG. 5 is a diagram for explaining the timing for starting driving assistance to the driver in consideration of the road width in the modification of the present invention. In other words, considering the situation where the host vehicle travels at a relatively high speed on a wide road such as two lanes on one side, the host vehicle changes the lane from the driving lane to the overtaking lane or from the overtaking lane to the driving lane. It is possible to avoid collision with an obstacle by steering. Therefore, even if it is determined that a road boundary exists based on the information stored in the map database 24, if a gap for one vehicle is formed between the road boundary and the obstacle, the vehicle and the obstacle This collision can be avoided by steering.

  Therefore, when it is determined that a road boundary exists, the steering avoidance is not impossible uniformly, that is, the steering avoidance distance Xb in that direction is not set to infinity, Considering the width of the road stored as information in the map database 24 and the gap between the road boundary and the obstacle detected using the camera 14 or the radar 20, the steering avoidance distance Xb in that direction is Calculated. At this time, as shown in FIG. 5 (B), the steering avoidance distance Xb is within a range where the own vehicle stops and reaches the boundary on the right side of the road by a combination of steering and braking, or by changing the lane by steering. Calculated within the range of the road width.

  Even in such a configuration, since the steering avoidance distance Xb is calculated in consideration of the road width as an actual road condition, the obstacle is detected early in response to the situation where the steering is limited to some extent by the position of the road boundary. The action of avoiding the collision is realized, and the driving support by the automatic brake and the warning due to the presence of the obstacle is started in a timely manner according to the actual road condition. In this case, the main ECU 12 calculates the steering avoidance distance Xb in consideration of the actual road width of the road detected by using the camera 14 and the radar 20, and the “steering avoidance” described in the claims is applied. "Distance calculation means" is realized. At this time, the road width may be calculated using an image captured by the camera 14 instead of the information stored in the map database 24.

It is a block diagram of the system which is one Example of this invention. It is a figure showing the relationship between the braking avoidance distance and the steering avoidance distance with the vehicle speed as a parameter. It is a figure for demonstrating the timing which starts the driving assistance to a driver | operator in the vehicle travel assistance apparatus of a present Example. It is a flowchart of the control routine performed in a present Example. It is a figure for demonstrating the timing which starts the driving assistance to a driver in consideration of a road width in the modification of this invention.

Explanation of symbols

10 Vehicle Driving Support Device 12 Electronic Control Unit (Main ECU)
14 Camera 16 Vehicle state sensor 20 Radar 22 Navigation device 24 Map database 30 Braking force control device 32 Alarm device Xa Braking avoidance distance Xb Steering avoidance distance Lf Actual distance between own vehicle and obstacle

Claims (8)

Steering avoidance distance calculation means for calculating a first collision avoidance distance to an obstacle capable of avoiding a collision with an obstacle of the host vehicle by steering, and an alarm to the driver based on the calculation result of the steering avoidance distance calculation means Or a vehicle travel support device comprising control means for performing automatic control of the vehicle,
The steering avoidance distance calculating means calculates the first collision avoidance distance in consideration of a road condition on which the host vehicle travels.   2. The vehicle travel according to claim 1, wherein the information representing the road condition is information on a road boundary that divides an area where a vehicle that affects steering avoidance of the vehicle can travel and an area where the vehicle cannot travel. Support device.   The vehicle travel support apparatus according to claim 1, wherein the information representing the road condition is obtained from a road map database storing map information.   The vehicle travel support apparatus according to claim 1, wherein the information representing the road condition is obtained from a beacon embedded in the road.   The steering avoidance distance calculation means includes a left steering calculation means for calculating a left steering collision avoidance distance to an obstacle that can be avoided by left steering in consideration of the situation on the left side of the road on which the host vehicle is traveling. 2. A right steering calculation means for calculating a right steering collision avoidance distance to an obstacle capable of avoiding a collision by right steering in consideration of a situation on a right side of a road on which the vehicle travels. The vehicle travel support apparatus described. The road condition includes a road width;
2. The vehicle travel support apparatus according to claim 1, wherein the steering avoidance distance calculating means calculates the first collision avoidance distance within a range that fits within a road width while avoiding a collision with an obstacle. . A braking avoidance distance calculating means for calculating a second collision avoidance distance to an obstacle capable of avoiding a collision of the own vehicle with an obstacle by braking;
2. The vehicle according to claim 1, wherein the control unit performs a warning for the driver or automatic control of the vehicle based on a calculation result of the steering avoidance distance calculation unit and a calculation result of the braking avoidance distance calculation unit. Driving support device. The control means is configured such that an actual distance from the host vehicle to the obstacle is shorter than the first collision avoidance distance calculated by the steering avoidance distance calculation means and the second distance calculated by the braking avoidance distance calculation means. 8. The vehicle travel support apparatus according to claim 7, wherein the vehicle is automatically braked when shorter than the collision avoidance distance.

Images