JP2006142904A - Brake control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid the danger that own vehicle is hit by another vehicle when an automatic brake is operated. <P>SOLUTION: A brake release timing by a brake control means 12 after a brake means 3 is operated accompanying with collision precognition by a collision precognition means 11 is made quicker at a dangerous position detected by a detection means 14 than a non-dangerous position. Thereby, it can quickly escape from the dangerous position. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a vehicle brake control device.

Based on the distance and relative speed between the host vehicle and the obstacle in front, it is determined whether or not the host vehicle may collide with the obstacle. When there is a collision possibility, that is, a collision is predicted. Automatic braking devices that automatically activate the braking means of the host vehicle are sometimes known. For example, Patent Literature 1 describes that in such an automatic brake device, the operation start timing of the brake means is changed based on a margin until the host vehicle collides with a front obstacle. Patent Document 2 describes that after the automatic brake is activated, the automatic brake is released when the distance between the host vehicle and the front obstacle becomes a predetermined value or more.
Japanese Patent Laid-Open No. 2004-210148 JP-A-5-24524

    However, if the automatic brake is applied at an intersection, a highway tunnel, a road with poor visibility, a road with a lot of traffic, or a road with a high traveling speed of other vehicles, Even if a collision with an obstacle is avoided, another vehicle easily collides with the host vehicle that has been decelerated or stopped.

    Therefore, an object of the present invention is to prevent the own vehicle from colliding with other vehicles (including automobiles, streetcars, and other railway vehicles) by the operation of the automatic brake.

    According to the present invention, in order to solve such a problem, the timing for releasing the automatic brake is differentiated between a dangerous place where the vehicle is likely to collide with another vehicle and a place where there is no or little such danger.

That is, the invention according to claim 1 is an obstacle detection means for detecting an obstacle ahead of the host vehicle;
A collision prediction means for determining whether or not the own vehicle may collide with the obstacle detected by the obstacle detection means;
A brake control device for a vehicle, comprising: brake control means for operating the brake means of the host vehicle when a collision is predicted by the collision prediction means;
Detecting means for detecting a dangerous point on the traveling path of the host vehicle that is likely to collide with another vehicle when the host vehicle decelerates or stops;
Brake release timing changing means for making the brake release timing by the brake control means after operating the brake means in accordance with the collision prediction differ between a dangerous place detected by the detection means and a non-dangerous place. It is characterized by.

    Therefore, when the host vehicle decelerates or stops due to the operation of the brake means associated with the above-mentioned collision prediction, the dangerous part can be quickly escaped by advancing the brake release timing to avoid a collision from another vehicle, or By delaying the release timing, it becomes possible to escape from a dangerous place while avoiding a collision from another vehicle.

The invention according to claim 2 is the invention according to claim 1,
The brake release timing changing means is characterized in that the brake release timing at the dangerous place is made earlier than the brake release timing at the non-dangerous place.

    That is, since there is a possibility of collision from another vehicle with respect to the host vehicle decelerated or stopped, it is not preferable that the brake release timing is delayed when it is necessary to quickly escape from the dangerous place. On the other hand, even if the brake release timing is advanced, the driver can hold the host vehicle in a decelerated or stopped state by operating the accelerator pedal or the brake pedal so as to avoid a collision from another vehicle. In view of this, the present invention is such that the brake release timing at the dangerous place is made earlier than the brake release timing at the non-dangerous place.

The invention according to claim 3 is the invention according to claim 2,
A calculation means for obtaining a stop position of the host vehicle when the brake means is operated in accordance with the prediction of the collision;
The detection means detects the dangerous point that exists between a point where the brake means is operated in accordance with the collision prediction and a stop position obtained by the stop position calculation means.

    Therefore, since the stop point when the brake is operated is obtained in advance and the presence of the dangerous point is detected within a limited range from the point where the brake is operated to the stop point, the dangerous point is detected on the traveling path of the host vehicle. The brake release timing is not changed only by the fact that there is, that is, the brake release timing is not unnecessarily advanced, which is advantageous in avoiding a collision between the host vehicle and an obstacle ahead of the host vehicle. On the other hand, when the brake means is operated, it is accurately detected that the host vehicle decelerates or stops at the dangerous place, so that the dangerous place is quickly escaped by accelerating the brake release timing. You can avoid being hit from.

The invention according to claim 4 is the invention according to claim 3,
The detection means further detects a risk level of the dangerous place,
The brake release timing changing means is characterized in that the brake release timing is advanced as the danger level of the dangerous part increases.

    That is, when the brake means is operated, the possibility that the own vehicle will collide with another vehicle depends on how difficult it is for the other vehicle to find the own vehicle or the vehicle speed of the other vehicle at the time when the own vehicle is found. Or whether the other vehicle has a road form in which it is difficult to avoid a collision with the host vehicle (for example, whether the road is narrow or a tunnel). In other words, even if it is a dangerous place, the degree of danger of being collided with another vehicle is different.

    Therefore, the risk level of the dangerous part is obtained, and the brake release timing is advanced as the risk level increases. Therefore, it is advantageous in quickly escaping the own vehicle from such a dangerous place, and the possibility of being collided with another vehicle is reduced.

The invention according to claim 5 is any one of claims 1 to 4,
The detection means performs the detection based on map information of vehicle-mounted navigation means for guiding the host vehicle to a travel destination.

    That is, it is dangerous if the host vehicle suddenly decelerates or stops at the intersection of roads, road corners, or tunnels, and whether the risk of such a dangerous point is high is determined by the road curvature, road Depending on the gradient and the visibility distance of the traveling path in relation to the structure around the road, that is, whether or not the other vehicle can easily find the vehicle, and further depending on the difference between the highway and the urban road, that is, other It depends on the vehicle speed. Thus, such road characteristics and topographical conditions related to the road can be grasped by a map. In view of this, the present invention is configured to detect the dangerous point and further detect the risk based on the map information of the navigation means for guiding the host vehicle to the travel destination.

The invention according to claim 6 is any one of claims 1 to 4,
The detection means performs the detection based on road traffic information acquired by road-to-vehicle communication.

    That is, the current location information of the host vehicle, static information about the road such as the above-described road characteristics and topographical information related to the road, and dynamic information such as the vehicle speed of other vehicles can be acquired by road-to-vehicle communication. Therefore, in the present invention, detection of the above-mentioned dangerous place and further detection of the degree of danger are performed based on such road traffic information provided from the outside.

    As described above, according to the present invention, the vehicle is provided with detection means for detecting a dangerous point that is likely to collide with another vehicle when the host vehicle decelerates or stops on the traveling path of the host vehicle, and predicts a collision with a front obstacle. Since the brake release timing after operating the brake means is made different between the dangerous place detected by the detection means and the non-hazardous place, the danger place can be increased by increasing the brake release timing at the dangerous place. It is possible to avoid the collision from the other vehicle and escape from the dangerous place by avoiding the collision from the other vehicle by escaping quickly and avoiding the collision from the other vehicle or delaying the release timing.

    Further, when the brake means is operated in accordance with the collision prediction, the stop position of the own vehicle is obtained, and when there is a dangerous place that is likely to be collided from another vehicle from the point where the brake means is operated to the stop position, According to the brake release timing being advanced, it is possible to accurately determine whether or not the host vehicle will decelerate or stop at the dangerous location, and reliably prevent collision with other vehicles. In addition, the presence of a dangerous point is determined within a limited range, so that the brake release timing is not unnecessarily advanced, and the collision of the vehicle with the obstacle predicted for the collision is avoided. Will be advantageous.

    Moreover, according to what advanced the said brake release timing, so that the danger level of a danger location becomes high, it becomes further advantageous in preventing that the own vehicle collides with another vehicle.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Overall configuration>
In the brake control device of the vehicle 1 shown in FIG. 1, 2 is a vehicle in front of the host vehicle, obstacle detection means for detecting other obstacles, 3 is brake means for operating the brakes of each wheel of the vehicle 1, and 4 is obstacles. A controller using a microcomputer that operates the brake means 3 when the host vehicle 1 may collide with an obstacle detected by the object detection means 2, that is, when a collision is predicted; A signal from the operation detection unit 10 that detects the operation of the brake unit 3 is input to the controller 4. Further, a three-point seat belt 6 is provided on the seat 5 on which an occupant is seated. The retractor 7 winds up the seat belt 6 with an electric motor at the time of the collision prediction, while the collision detection means 8 uses the vehicle for obstacles. A pretensioner mechanism 9 is provided that explodes explosives and irreversibly winds up the seat belt 6 when a collision is detected. The operation of the pretensioner mechanism 9 is controlled by the controller 4.

    As shown in FIG. 2, the controller 4 includes a collision prediction unit 11 that determines the possibility of collision of the host vehicle 1 against an obstacle detected by the obstacle detection unit 2, and the brake unit 3 based on the collision prediction. Brake control means 12 for controlling the operation of the vehicle, and in order to change the brake release timing given to the brake means 3 by the brake control means 12, the stop position of the host vehicle when the brake means 3 is operated is determined. A stop position calculation means 13 to be obtained, a dangerous point detection means 14, and a brake release timing change means 15 are provided.

    The collision prediction means 11 calculates the relative speed and relative acceleration between the host vehicle and the obstacle ahead of the host vehicle based on the output of the obstacle detection unit 2, and obtains the safe inter-vehicle distance of the host vehicle. A collision is predicted when the distance to the obstacle is less than the safe inter-vehicle distance. That is, the obstacle detection means 2 is constituted by a millimeter wave radar, and the distance between the own vehicle and the obstacle is obtained by the time until the radar wave emitted from the own vehicle is reflected by the obstacle and returns. It is done. Further, the relative speed and the relative acceleration are obtained based on the time change of the distance, and a preset safe inter-vehicle distance corresponding to the relative speed and the relative acceleration is given.

    Thus, when the collision is predicted by the collision prediction means 11, the brake control means 12 controls the brake means 3 based on the vehicle speed of the host vehicle, the relative speed, the relative acceleration, the inter-vehicle distance, and the like. (Brake start timing Ts, brake strength (target deceleration G), and brake release timing) are set. The brake release timing is set, for example, when the vehicle speed becomes 0 km / h.

The stop position calculation means 13 calculates the braking time Te until the brake end when the brake means 3 is operated at the timing Ts from the current vehicle speed V of the host vehicle and the deceleration G due to the operation of the brake means 3. When the vehicle speed Ve = 0 at the end of braking and the deceleration G = 0.5 × 9.8 m / s ² ,
Ve = V−G × Te
0 = V−0.5 × 9.8 × Te
Te = V / (0.5 × 9.8) [sec]
It becomes.

And the stop position calculation means 13 calculates | requires the moving distance S of the own vehicle in the said brake time Te,
S = V × Te−1 / 2 × G × Te ²
The brake end point moved S [m] from the brake start point at which the brake means 3 is operated at the timing Ts is calculated from the map information of the navigation means described later.

    Based on the data acquired from the road traffic data supply means 16, the dangerous point detection means 14 is likely to collide with other vehicles when the host vehicle 1 decelerates or stops in the brake section from the brake start point to the brake end point. Whether or not there is a dangerous spot and the degree of danger are detected.

    The data supply means 16 obtains the information from the navigation means provided in the own vehicle 1 for guiding the own vehicle 1 to the travel destination, and the beacon receiving antenna from the communication network providing road traffic information such as VICS. And an information receiver.

   That is, the navigation means receives a transmission radio wave from a GPS artificial satellite, and based on this, detects a change in the traveling direction of the host vehicle and a GPS antenna / receiver for calculating the current location and traveling direction of the host vehicle. A gyro compass for the vehicle, a vehicle speed sensor for the own vehicle, an input means for the occupant to input various commands such as input of the travel destination of the host vehicle, designation of a travel route from the current location to the destination, and map information A player for reading out the map information from a stored storage medium (DVD or CD-ROM), a display for displaying a road map and the current location, and information from each of these means are incorporated to mainly store the vehicle. Navigation control to display the current location, direction of travel, destination, travel route, etc. on the display to guide the driver of the vehicle to the driver And a knit.

    In the storage medium, as map information, road maps, railway maps, river water map, etc., road width, lane width, road type (highway, suburban roads and urban roads), one-way Other road attributes, the altitude of each point on the road, the position of the traffic light, etc. are stored.

    The road traffic information receiver obtains the current location information, branch point information, road guidance information, accident information, traffic jam information, and other dynamic information about the flow of vehicles from the communication network that provides the road traffic information. To do.

    In the case of this embodiment, the map information of the navigation means and the information on the road and traffic obtained by the road traffic information receiver are used as data for the detection by the dangerous point detection means 14.

    The dangerous point detection means 14 detects the presence of a dangerous point in the brake section and the degree of danger from the following viewpoints 1-4. That is, based on a plurality of pieces of information related to the risk of being easily collided with other vehicles in the brake section, the risk level is evaluated as a risk location.

  1. Is there a place in the brake section where the other vehicle discovers the vehicle (the driver of the other vehicle discovers, the same applies hereinafter) that is likely to be delayed. As this timing is delayed, the driving operation for avoiding the collision of the other vehicle with the host vehicle is delayed, and the risk of collision increases.

    Specifically, information A regarding the road gradient (the stronger the uphill, the more difficult it is to see from the uphill position where the road has moved from the uphill to the flat road or downhill, so the timing of the discovery is delayed and the risk is high) , Information B regarding road curvature (the greater the road curvature, the more difficult it is to find a vehicle in which the curved portion and the portion following the curved portion cannot be seen in front of the curved portion, so the timing of the discovery is delayed and the risk is high) In addition, information C regarding the road visibility distance in relation to roadside trees, buildings, etc. is obtained from the map information of the navigation means (the shorter the visibility distance C, the later the timing of the above discovery and the higher the risk). The information is evaluated numerically (for example, 10-level evaluation).

  2. Is there a place in the brake section where the vehicle speed of the other vehicle is predicted to be high when the other vehicle is found by the other vehicle? The higher the vehicle speed of the other vehicle, the higher the degree of danger because it is likely to collide with the host vehicle even if the avoidance driving operation is performed.

    Specifically, information D regarding the flow of the vehicle obtained by the road traffic information receiver (has a higher degree of danger as the flow of the vehicle becomes higher), information E regarding the type of road obtained from the map information (other vehicles on highways) The vehicle speed is high and the danger level is high), and the road width information F (the wider the road width, the higher the vehicle speed of other vehicles and the higher the danger level) is evaluated numerically.

  3. Is there a location in the brake section where other vehicles cannot avoid a collision? The longer the distance that cannot be avoided, the higher the risk.

    Specifically, information G regarding the distance at which the brake section and the tunnel without a retreat road overlap (the longer the overlap distance, the more the other vehicle cannot avoid the collision and the higher the risk), and the right turn intersection overlaps Information H about distance (the longer the overlapping distance is, the more vehicles cannot avoid collision and the higher the risk) is obtained from the map information, and the information is evaluated numerically (for example, 10-step evaluation).

  4). Is there a location where an accident occurred before in the above brake section? The risk increases as the number of accidents at the location increases.

    Specifically, when the road traffic information provider provides past accident information, the accident information I obtained by the road traffic information receiver (the accident history at each point is stored in the storage medium of the vehicle-mounted navigation means). If it is stored, the accident information) is evaluated numerically.

Next, the dangerous part detection means 14 gives a coefficient (weighting) according to the influence of the information A to I on the risk of the information, and obtains the evaluation level Z of the risk level. That is,
Z = A × a + B × b + C × c +... + I × i
In this case, uppercase letters such as A, B, and C are evaluation values, and lowercase letters such as a, b, and c are corresponding coefficients. The dangerous spot detection means 14 sets a case where the evaluation level Z is equal to or higher than a predetermined value as a dangerous spot where the brake release timing described later should be advanced.

    Then, the brake release timing changing means 15 advances the brake release timing by the brake control means 12 when the dangerous place detecting means 14 detects that a dangerous place exists in the brake section. In this case, the brake release timing changing means 15 advances the release timing as the risk evaluation level Z is higher.

    In the case of the present embodiment, the dangerous point detection means 14 is based on the evaluation level Z, the risk level is small (Z <first predetermined value), the risk level is medium (first predetermined value ≦ Z <second predetermined value), and the risk level. The degree of danger is judged in three stages of large (Z ≧ second predetermined value), and the places where the degree of danger is high and the degree of danger are high are designated as dangerous places where the brake release timing should be changed. The brake release timing changing means 15 greatly increases the release timing when the degree of danger is greater than when the degree of danger is medium.

    FIG. 3 shows a flow of brake release timing change control by the controller 4. In step S1 after the start, the possibility of collision by the collision predicting means 11 is determined. When it is determined that there is a possibility of collision, the process proceeds to step S2, the brake control condition is set by the brake control means 12, and the brake control is started. The

    In the next step S3, it is detected by the dangerous part detecting means 14 whether or not there is a dangerous part in the brake section obtained by the stop position calculating means 13, and if there is a dangerous part, the process proceeds to step S4 and the degree of danger is determined. It is determined whether or not it is small. When there is no danger point or when the danger level is low, the process proceeds to step S5, and the brake control is continued without changing the brake release timing.

    When it is determined in step S4 that the degree of risk is not low, the process proceeds to step S6, and it is determined whether or not the degree of risk is medium. When it is determined that the degree of danger is medium, the process proceeds to step S7, where the brake release timing is advanced by the brake release timing changing means 15 (changed to the vehicle speed of 5 km / h) and the brake control is continued. If it is determined in step S6 that the degree of danger is not in danger (when the degree of danger is high), the process proceeds to step S8, where the brake release timing changing means 15 further advances the brake release timing (changed to a vehicle speed of 10 km / h). ) Brake control continues.

    Therefore, the brake control of the present invention will be described based on a specific example. As shown in FIG. 4, for example, when the host vehicle 1 approaches an intersection of a road, a front obstacle (in this case, a forward traveling vehicle) 21 It may be predicted that there is a possibility of collision. In that case, if the brake means 3 is operated so that the vehicle speed of the host vehicle 1 becomes zero as planned, the vehicle stops at the intersection, and travels in the opposite lane and comes from the other vehicle 22 approaching the intersection. There is a possibility of a collision.

    On the other hand, according to the present invention, the brake section L when the brake means is operated is obtained, and when there is an intersection in the brake section L, it is determined that there is a dangerous place, and the vehicle speed of the host vehicle becomes zero. Before, the operation of the brake means 3 is released.

    Therefore, the own vehicle 1 can escape from the intersection without stopping in the intersection, and a collision with the other vehicle 22 is avoided. In this case, the host vehicle 1 may approach the forward traveling vehicle 21 that is an obstacle, but the driver can avoid a collision with the forward traveling vehicle 21 by his / her accelerator operation or brake operation.

    In the above embodiment, in addition to static information such as road characteristics, road-related topographical conditions, and past accident histories, vehicle speed information of other vehicles obtained from VICS, brake sections, and tunnels and right-turn intersections overlap. The dynamic information obtained during travel of the vehicle, such as the distance, was used to determine the dangerous location and its risk level. Based on the static information, the road risk location and the risk level are determined in advance and recorded on the recording medium. In addition, based on the information recorded on the recording medium, it may be determined whether or not there is a dangerous point in the brake section, and further, the degree of danger may be obtained. You may make it correct | amend based on.

    In the above embodiment, the brake release timing is set when the vehicle speed becomes zero at the non-hazardous location (including a low risk level), but when the vehicle speed becomes lower than the predetermined vehicle speed, the release threshold is set at the predetermined vehicle speed at the dangerous location. You may make it set to the higher vehicle speed side.

    In addition, the brake release threshold is set not by the vehicle speed as described above, but by the amount of decrease in the vehicle speed, and the amount of decrease is made smaller in the dangerous part than in the non-dangerous part (for example, the non-dangerous part has a reduction amount of 30 km / h or more The brake release timing may be advanced by setting the amount to a reduction amount of 20 km / h or more.

    Furthermore, when the brake release threshold value is set by the distance between the host vehicle and the front obstacle, the release timing may be advanced by making the distance shorter in the dangerous part than in the non-dangerous part.

    In short, the present invention does not ask how to set the brake release timing.

It is a block diagram which shows the brake control apparatus of a vehicle. It is a control block diagram of the control device. It is a control flowchart of the same control apparatus. It is explanatory drawing which shows the example which advances brake releasing timing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Own vehicle 2 Obstacle detection means 3 Brake means 4 Controller 11 Collision prediction means 12 Brake control means 13 Stop position calculation means 14 Hazardous location detection means 15 Brake release timing change means 21 Obstacle 22 Other vehicle

Claims (6)

Obstacle detection means for detecting an obstacle ahead of the host vehicle;
A collision prediction means for determining whether or not the own vehicle may collide with the obstacle detected by the obstacle detection means;
A brake control device for a vehicle, comprising: brake control means for operating the brake means of the host vehicle when a collision is predicted by the collision prediction means;
Detecting means for detecting a dangerous point on the traveling path of the host vehicle that is likely to collide with another vehicle when the host vehicle decelerates or stops;
Brake release timing changing means for making the brake release timing by the brake control means after operating the brake means in accordance with the collision prediction differ between a dangerous place detected by the detection means and a non-dangerous place. A brake control device for a vehicle. In claim 1,
The brake control device for a vehicle according to claim 1, wherein the brake release timing changing means advances the brake release timing at the dangerous place earlier than the brake release timing at the non-dangerous place. In claim 2,
A calculation means for obtaining a stop position of the host vehicle when the brake means is operated in accordance with the prediction of the collision;
The vehicle brake according to claim 1, wherein the detection means detects the dangerous point existing between a point where the brake means is operated in accordance with the collision prediction and a stop position obtained by the stop position calculation means. Control device. In claim 3,
The detection means further detects a risk level of the dangerous place,
The vehicle brake control device according to claim 1, wherein the brake release timing changing means advances the brake release timing as the risk level of the dangerous part increases. In any one of Claims 1 thru | or 4,
The vehicle brake control device according to claim 1, wherein the detection means performs the detection based on map information of an in-vehicle navigation means for guiding the host vehicle to a travel destination. In any one of Claims 1 thru | or 4,
The vehicle brake control apparatus, wherein the detection means performs the detection based on road traffic information acquired by road-to-vehicle communication.

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