JP4873186B2 - Collision mitigation device - Google Patents

Description

  The present invention relates to a collision mitigation device mounted on a vehicle, and more particularly to a collision mitigation device that reduces or avoids a collision by estimating a collision state between the host vehicle and another vehicle and performing brake control.

Patent Document 1 discloses an occupant protection device that reduces or avoids a collision by estimating a collision state between the host vehicle and another vehicle and performing brake control. This occupant protection device performs a deceleration control (brake control) corresponding to a collision site in order to estimate a collision site between the host vehicle and another vehicle and reduce or avoid the collision. Patent Document 1 describes that, instead of the collision part, a collision angle between the host vehicle and another vehicle is estimated and deceleration control is performed according to the collision angle.
JP 2007-210563 A

  In Patent Document 1, since only one of the collision part and the collision angle is considered, it is difficult to accurately determine the degree of influence on the host vehicle due to the collision (degree of injury; hereinafter referred to as the degree of injury). is there. This is because even if the collision site is the same, the degree of injury is not always the same, and even if the collision angle is the same, the degree of injury is not necessarily the same. In Patent Document 1, since the degree of injury cannot be accurately determined, there is a case where optimal brake control cannot be performed in order to reduce or avoid the collision (from the viewpoint of the degree of injury). .

  SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a collision mitigation device capable of performing more accurate brake control in order to reduce or avoid collision.

  In order to solve the above problems, the present invention employs the following configuration. That is, the first invention is a collision mitigation device that reduces or avoids a collision by performing brake control when it is estimated that the host vehicle collides with another vehicle. The collision mitigation device includes a collision site estimation unit, a collision angle estimation unit, a punching site estimation unit, and a control unit. The collision site estimation unit estimates a collision site that is the position of the host vehicle where another vehicle is expected to collide. The collision angle estimation unit estimates a collision angle at which another vehicle collides with the host vehicle. The punching site estimation unit estimates a punching site when another vehicle has passed through the host vehicle from the collision site and the collision angle. A control part determines the content of brake control based on a collision site | part and a penetration site | part.

  In the second invention, the punching site estimation unit may estimate a position where a straight line extending from the collision site in a direction determined by the collision angle penetrates the host vehicle as the punching site.

  In the third invention, the control unit may determine the content of the brake control using at least the distance from the collision site to the punching site.

  In 4th invention, a control part may determine the timing which starts brake control so that it becomes early, so that distance is long.

  In the fifth invention, the control unit may determine the content of the brake control using at least a combination of the collision site and the punching site.

  In a sixth aspect of the invention, when the collision site and the protruding site are at the position of the cabin of the own vehicle, the control unit sets the timing for starting the brake control so that at least one of the collision site and the protruding site is higher than the cabin of the own vehicle. You may determine so that it may become earlier than the case where it is a previous position.

  In a seventh aspect of the invention, the control unit performs control so as not to perform brake control before the collision, at least on the condition that at least one of the collision site and the protruding site is a position behind the cabin of the host vehicle. May be.

  In the eighth invention, the control unit determines the timing so as to perform the brake control after the collision when the condition is satisfied.

  In the ninth invention, the control unit may use as a further condition that the distance from the collision site to the punch-out site is shorter than a predetermined distance.

  In a tenth aspect of the invention, the collision mitigation device further includes an injury degree calculation unit that calculates an injury degree that is the degree of injury of the host vehicle when the vehicle collides with another vehicle based on the collision site and the punching site. Also good. At this time, a control part determines the timing which starts brake control based on an injury degree.

  In the eleventh aspect, the control unit may determine the timing for starting the brake control based on the collision site and the punching site. In the twelfth aspect, the control unit may calculate a threshold value related to a collision time until the host vehicle and another vehicle collide based on the collision site and the punching site. At this time, the collision mitigation apparatus further includes a collision time calculation unit that repeatedly calculates the collision time at predetermined time intervals, and a control execution unit that starts brake control when the collision time becomes smaller than the threshold.

  In a thirteenth aspect, the control unit may determine whether to perform brake control based on the collision site and the punching site. In the fourteenth invention, the control unit may determine the deceleration rate by the brake control based on the collision site and the punching site.

  According to the first invention, the collision mitigation apparatus estimates a protruding part from the collision part and the collision angle, and determines the content of the brake control based on the collision part and the protruding part. That is, according to the first invention, the content of the brake control is determined in consideration of the protruding portion in addition to the collision portion, so that the degree of injury of the host vehicle can be determined with higher accuracy to determine the content of the brake control. Can do. Thereby, the content of the brake control can be determined more appropriately.

  According to the second aspect of the invention, the collision mitigation device can accurately calculate the punching site from the collision site and the collision angle.

  According to the third invention, the content of the brake control is determined using the distance from the collision site to the punching site (punching distance). Further, according to the fourth invention, as the content of the brake control, the brake timing is determined to be faster as the punching distance is longer. Here, the punch-out distance is an important index for evaluating the degree of injury when the host vehicle collides with another vehicle. Specifically, the longer the punch-out distance, the greater the degree of injury. Therefore, according to the third and fourth aspects, by determining the content of the brake control (brake timing) based on the punching distance, it is possible to determine the degree of injury with high accuracy and determine the content of the brake control. .

  According to the fifth aspect, the content of the brake control is determined using the combination of the collision site and the punching site. Here, the combination is an important index for evaluating the degree of injury when the host vehicle collides with another vehicle, and the degree of injury is considered to change depending on where the collision site and the punching site are located. Therefore, according to the fifth aspect, by determining the content of the brake control based on the above combination, it is possible to accurately determine the degree of injury and determine the content of the brake control.

  Further, according to the sixth invention, when the collision site and the punching site are the positions of the cabin of the own vehicle, at least one of the collision site and the punching site is a position before the cabin of the own vehicle. Since the brake timing is determined to be earlier, the degree of injury can be determined with high accuracy and the brake timing can be determined.

  According to the seventh aspect of the invention, when at least one of the collision site and the protruding site is behind the cabin, the brake control is not performed until the collision between the host vehicle and the other vehicle. Here, if the brake control is performed in the above case, the collision site and the projecting site are changed to the cabin position of the host vehicle, and as a result, the degree of injury may be increased. That is, according to the seventh aspect, it is possible to prevent the degree of injury from being increased by performing the brake control. Furthermore, according to the eighth invention, secondary damage after the collision can be prevented by performing the brake control after the collision in the above case.

  Further, according to the ninth aspect, since the brake timing is determined in consideration of the above-mentioned punching distance in addition to the combination of the collision part and the punching part, the brake timing is determined by determining the degree of injury more accurately. Can do.

  According to the tenth aspect of the present invention, the degree of injury is actually calculated based on the collision part and the punching part, and the brake timing is determined based on the calculated degree of injury, so that the brake timing considering the degree of injury can be easily performed. Can be determined.

  According to the eleventh aspect, since the brake timing changes based on the collision site and the punching site, the brake control can be started at an appropriate timing.

  According to the twelfth aspect, the threshold value related to the collision time is determined based on the collision site and the punching site. According to this, even when it is determined whether or not to perform brake control using the collision time, the brake timing can be determined in consideration of the collision site and the punching site.

  According to the thirteenth aspect, whether or not the brake control is performed changes based on the collision part and the punching part, so that it is possible to appropriately determine whether or not the brake control is necessary.

  According to the fourteenth aspect, since the deceleration rate by the brake control changes based on the collision site and the punching site, the brake control can be performed with an appropriate deceleration rate.

  Hereinafter, a collision mitigation device according to an embodiment of the present invention will be described. FIG. 1 is a block diagram showing the configuration of the collision mitigation apparatus according to this embodiment. As shown in FIG. 1, the collision mitigation apparatus includes a radar 1, a radar ECU (Electronic Control Unit) 2, a steering angle sensor 3, a yaw rate sensor 4, a wheel speed sensor 5, a control ECU 6, and a brake ECU 7. The collision mitigation apparatus shown in FIG. 1 is mounted on a vehicle, estimates whether or not the own vehicle collides with an obstacle (another vehicle), and reduces the collision by performing brake control when it is estimated that the vehicle collides. It is something to avoid.

(Configuration of each part of collision mitigation device)
Hereinafter, each part which comprises a collision mitigation apparatus is demonstrated. The radar 1 is typically a millimeter wave radar and detects an obstacle existing around the host vehicle. That is, the radar 1 transmits (radiates) electromagnetic waves (millimeter waves) and receives the reflected waves reflected by the obstacle. The radar 1 outputs a signal (radar signal) indicating the reception result to the radar ECU 2. In addition, it is preferable that the radar 1 is attached to the diagonal direction of the front end or rear end of the own vehicle, or the side surface of the own vehicle so that the other vehicle approaching from the side of the own vehicle can be detected. In the present embodiment, the radar 1 is attached to six locations, ie, the center, left end, and right end of the front end of the host vehicle, and the center, left end, and right end of the rear end. In other embodiments, the radar 1 may be attached in any number, and the attachment position may be any position.

  The radar ECU 2 is an information processing device including a CPU, a memory, and the like, and detects other vehicles based on the radar signal. Specifically, the radar ECU 2 determines the presence or absence of another vehicle around the host vehicle based on the radar signal, and calculates the position and speed of the other vehicle when the other vehicle exists around the host vehicle. The position of the other vehicle is calculated based on the time from transmission to reception of the electromagnetic wave, the distance from the own vehicle to the other vehicle, and the direction of the other vehicle calculated based on the angle of the received electromagnetic wave. It can be calculated from The speed of the other vehicle can be calculated from the frequency change between the transmission wave and the reception wave. The other vehicle information (position and speed of the other vehicle) calculated by the radar ECU 2 is output to the control ECU 6. The radar ECU 2 repeatedly performs radar signal reception and other vehicle information calculation and output operations at predetermined time intervals.

  The steering angle sensor 3, the yaw rate sensor 4, and the wheel speed sensor 5 are sensors for detecting information about the host vehicle that is used to determine whether or not the host vehicle and another vehicle collide. The steering angle sensor 3 detects the steering angle of the steering wheel. Information on the detected steering angle is output to the control ECU 6. The yaw rate sensor 4 detects the yaw rate acting on the host vehicle. Information on the detected yaw rate is output to the control ECU 6. The wheel speed sensor 5 detects the wheel speed of each wheel. Information on the detected wheel speed (specifically, a wheel pulse signal) is output to the control ECU 6.

  The control ECU 6 is an information processing device including a CPU, a memory, and the like, and controls the brake of the vehicle based on various pieces of information (information on other vehicle information, steering angle, yaw rate, and wheel speed). Specifically, the control ECU 6 predicts whether or not the host vehicle collides with another vehicle using the above-mentioned various information, and performs brake control when it is predicted that the host vehicle will collide. In addition, when it is predicted that a collision will occur, the control ECU 6 determines the degree of injury (of the own vehicle) due to the collision (referred to as the degree of injury) based on the above-mentioned various information, and performs the brake control timing (referred to as brake timing). ) Is changed according to the degree of injury. Details of the process for determining the degree of injury and the process for determining the brake timing will be described later.

  In addition to the brake control, the control ECU 6 controls the operation of the airbag provided in the host vehicle, warns the driver, and controls the steering when a collision is predicted. Processing may be performed.

  The brake ECU 7 is an information processing device including a CPU, a memory, and the like, and controls the braking force of each wheel according to a control signal from the control ECU 6. For example, when the control signal indicating the target braking force is input from the control ECU 6, the brake ECU 7 performs control to adjust the hydraulic pressure of the wheel cylinder of each wheel so that the target braking force is obtained.

(Overview of collision mitigation device operation)
Next, with reference to FIG. 2, the outline | summary of operation | movement of the collision mitigation apparatus shown in FIG. 1 is demonstrated. In the present embodiment, the collision mitigation apparatus calculates the collision site and the punching site of the host vehicle based on the various pieces of information in order to determine the degree of injury. The collision site is the position of the host vehicle where another vehicle is expected to collide (see point P shown in FIG. 2). The punch-out site is a punch-through position when another vehicle that has collided has passed through the host vehicle (see point Q shown in FIG. 2).

  FIG. 2 is a diagram showing a relationship between examples of three collision states with different degrees of injury and brake timing in each of the collision states. In FIG. 2, the state (a) is a state in which the collision part and the protruding part are at the front side of the cabin of the host vehicle 11, and the state (b) is a state in which the collision part and the protruding part are in the cabin of the host vehicle 11. It is a state in the position, and state (c) is a state in which the collision part and the punching part are on the rear side of the cabin of the host vehicle 11.

  In the state (b), since the collision part and the punching part are both in the cabin position of the own vehicle 11, the collision is such that the other vehicle 12 directly hits the cabin of the own vehicle 11. can do. On the other hand, in the state (a), since the collision site and the protruding site are both in front of the cabin of the host vehicle 11, the other vehicle 12 does not directly collide with the cabin of the host vehicle 11. Therefore, it can be determined that the degree of injury in the state (a) is relatively small compared to the state (b). On the other hand, in the state (c), since the collision part and the punching part are both located behind the cabin of the own vehicle 11, the other vehicle 12 does not directly collide with the cabin of the own vehicle 11. Therefore, similarly to the state (a), it can be determined that the degree of injury in the state (c) is relatively small compared to the state (b). In the state (c), since the distance from the collision site to the punching site (referred to as the punching distance) is shorter than that in the state (a), the degree of injury in the state (c) is relatively small compared to the state (a). It can be determined that it is small. From the above, the degree of injury in each state (a)-(c) is the highest in the state (b), the degree of injury in the state (a) is medium, and the degree of injury in the state (c) is the highest. It can be determined that it is small. In this way, it is possible to determine the degree of injury of the host vehicle when it collides with another vehicle using the collision part and the punching part.

  In this embodiment, the collision mitigation device changes the brake timing according to the degree of injury. That is, as shown in FIG. 2, in the state (b) where the degree of injury is judged to be relatively large, the brake timing is set relatively early and the state where the degree of injury is judged to be relatively small (c). ), The brake timing is set relatively late, and in the state (a) where the degree of injury is determined to be medium, the brake timing is set to medium. Thus, this collision mitigation device makes it possible to perform more accurate brake control by considering the degree of injury.

  In the present embodiment, the collision mitigation apparatus sets the brake timing to the time after the collision in the state (c) shown in FIG. The reason why the brake control is not performed before the collision is that if the brake control is performed before the collision in the state (c), the degree of injury is larger, for example, when the other vehicle 12 collides with the cabin of the own vehicle 11. This is because there is a possibility of becoming. The reason why the brake control is performed after the collision is to prevent secondary damage in which the own vehicle 11 colliding with the other vehicle 12 collides with another vehicle. In another embodiment, in the state (c), the brake control may not be performed simply (even after the collision).

(Operation details of collision mitigation device)
Next, the details of the operation of the collision mitigation apparatus shown in FIG. 1 will be described with reference to FIGS. FIG. 3 is a flowchart showing a flow of processing of the collision mitigation apparatus shown in FIG. The process in the flowchart shown in FIG. 3 is executed, for example, when the ignition switch is on or when the host vehicle is traveling.

  In FIG. 3, first in step S1, the control ECU 6 executes a brake timing determination process. The brake timing determination process is a process for determining a timing (brake timing) at which brake control is started in order to avoid a collision between the host vehicle and another vehicle. Here, in the present embodiment, the control ECU 6 uses a collision time (TTC (Time To Collation)) to determine whether or not the own vehicle collides with another vehicle (highly likely). The collision time is a parameter that represents the time from the present time until the host vehicle collides with another vehicle. The control ECU 6 calculates the collision time (step S2 to be described later), and determines whether or not the own vehicle collides with another vehicle based on whether or not the collision time has exceeded a threshold value (step S3 to be described later). And when it determines with the own vehicle colliding with another vehicle, brake control is performed (step S4 mentioned later). Therefore, when the threshold value is large, it is determined that the host vehicle and the other vehicle collide at a relatively early timing, and the brake control is started at a relatively early timing. On the other hand, when the threshold value is small, it is determined that the host vehicle and the other vehicle collide at a relatively late timing, and the brake control is started at a relatively late timing. As described above, when the collision is determined using the collision time, it is possible to change the brake timing by changing the threshold value. In the present embodiment, the control ECU 6 determines the brake timing by determining the threshold value in the brake timing determination process. Details of the brake timing determination process will be described below.

  FIG. 4 is a flowchart showing a detailed process flow of the brake timing determination process (step S1) shown in FIG. In FIG. 4, first, in step S <b> 11, the control ECU 6 acquires the other vehicle information described above from the radar ECU 2. In subsequent step S <b> 12, the control ECU 6 acquires information on the steering angle from the steering angle sensor 3. In subsequent step S <b> 13, the control ECU 6 acquires yaw rate information from the yaw rate sensor 4.

  In step S14 following step S13, the control ECU 6 calculates the curve radius of the host vehicle. The curve radius is a radius of the track of the host vehicle when the host vehicle is curved, and is calculated based on the steering angle and the yaw rate acquired in steps S12 and S13. Following step S14, the process of step S15 is executed.

  In step S <b> 15, the control ECU 6 acquires wheel speed information from the wheel speed sensor 5. In subsequent step S16, the control ECU 6 calculates the speed of the host vehicle based on the wheel speed acquired in step S15.

  In step S <b> 17 subsequent to step S <b> 16, the control ECU 6 calculates a track predicted to be passed by another vehicle. The predicted trajectory of the other vehicle is calculated based on the other vehicle information acquired in step S11. In subsequent step S18, the control ECU 6 calculates a track predicted to be passed by the host vehicle. The predicted track of the host vehicle is calculated based on the curve radius calculated in step S14. Based on the track of the host vehicle and the other vehicle estimated in the above steps S17 and S18, an angle (collision angle) at which the other vehicle collides with the host vehicle can be calculated. That is, in step S19, the control ECU 6 estimates the collision angle based on the track of the host vehicle and the other vehicle. In this embodiment, control ECU6 which performs step S19 is equivalent to the collision angle estimation part as described in a claim. Following step S19, the process of step S20 is executed.

  In addition, the own vehicle and the other vehicle collide with each other using the track of the own vehicle and the other vehicle, or the track of the own vehicle and the other vehicle, the own vehicle speed, and the other vehicle speed (there is a possibility of collision). It is possible to determine whether or not. Therefore, in other embodiments, the control ECU 6 determines whether or not the own vehicle and the other vehicle collide before step S19, and only when the collision is determined to occur, the process of steps S19 to S23 is performed. May be executed. Moreover, you may make it perform the process of step S2-S4 mentioned later only when it determines with colliding.

  In step S20, the control ECU 6 estimates the collision site. The collision site is estimated based on the trajectories of the host vehicle and the other vehicle, the host vehicle speed calculated in step S16, and the other vehicle information (specifically, information on the other vehicle speed) acquired in step S11. be able to. In this embodiment, control ECU6 which performs step S20 is equivalent to the collision site | part estimation part as described in a claim. Following step S20, the process of step S21 is executed.

  In step S21, the control ECU 6 estimates a protruding portion. The punch-out site can be estimated based on the collision angle obtained in step S19, the collision site obtained in step S20, and the host vehicle speed and the other vehicle speed described above. In the present embodiment, the control ECU 6 that executes step S21 corresponds to a punch-out site estimation unit described in claims. Hereinafter, an example of a method for calculating the protruding portion will be described with reference to FIGS. 5 and 6.

  FIG. 5 and FIG. 6 are diagrams for explaining a method of calculating the protruding portion. In the present embodiment, the xy coordinate system shown in FIGS. 5 and 6 is used to represent the position of each part of the host vehicle 11 (position on the horizontal plane). In the xy coordinate system, the vehicle width direction (left-right direction) of the host vehicle 11 is the x axis, and the straight direction (front-rear direction) of the host vehicle 11 is the y axis. Here, the right direction of the host vehicle 11 is the x-axis positive direction, and the front direction of the host vehicle 11 is the y-axis positive direction. The origin of the xy coordinate system is the center position of the front end of the host vehicle 11. Since the size of the host vehicle 11 is known, the x coordinate value DL of the left end of the host vehicle 11, the x coordinate value DR of the right end of the host vehicle 11, and the y coordinate value L of the rear end of the host vehicle 11 are It is a known value.

  In the present embodiment, the protruding portion Q is calculated as a position where a straight line extending from the collision portion P in a direction determined by the collision angle ε penetrates the host vehicle. Hereinafter, as illustrated in FIG. 5A, a method for calculating the punching site will be described using a case where the collision site P is on the left side as an example. FIG. 5A is a diagram showing a collision site and a punch-out site in the host vehicle 11. FIG.5 (b) is a figure which shows the vector showing the own vehicle speed and other vehicle speed. In FIG. 5B, the collision angle ε is determined by a vector V0 representing the host vehicle speed and a vector V1 representing the other vehicle speed, and specifically, an angle formed by −V0 and V1.

In FIG. 5, a line segment connecting the collision site P and the punching site Q is assumed to be a hypotenuse, and a right triangle is considered in which the remaining two sides are parallel to the x-axis and the y-axis, respectively. Since this right triangle is similar to the right triangle ABC shown in FIG. 5B, if the collision site P = (CPx, CPy), the punching site Q = (CQx, CQy) is expressed by the following equation (1): Can be expressed as
(CQx−CPx): (CQy−CPy) = V1sinε: V0 + V1cosε (1)
Furthermore, since the x-coordinate value CQx of the punching site is known (= DR), the unknown CQy can be calculated from the following equation (2) obtained by modifying the above equation (1).
CQy = CPy − {(CQx−CPx) · (V0 + V1cosε) / V1sinε} (2)
In the above equation (2), since the variables CPy, CQx, CPx, V0, V1, and ε on the left side are known, the y coordinate value CQy of the protruding portion can be calculated by the above equation (2).

  As shown in FIG. 6, when the collision site P1 is located on the front surface of the host vehicle 11 and the punching site Q1 is located on the side surface of the host vehicle 11, only the coordinates of the collision site are changed compared to FIG. As a result, the protruding portion can be calculated using the above equation (2).

  As shown in FIG. 6, when the collision site P2 is located on the side surface of the host vehicle and the projecting site Q2 is located on the rear surface of the host vehicle, the coordinate value calculated by the above equation (2) is This indicates the position of the position Q2 ′, not Q2. Therefore, in this case (specifically, when CQy calculated by the above equation (2) is smaller than the y-coordinate value L of the rear end of the host vehicle 11), the collision site Q2 can be calculated by the following method. Good. That is, since the y-coordinate value of the projecting site Q2 is known (= L), it is higher than the difference obtained by subtracting the y-coordinate value of the projecting site Q2 from the y-coordinate value of the crash site P2, and the y-coordinate value of the projecting site Q2. A ratio with the difference obtained by subtracting the y coordinate value of the position Q2 ′ calculated by the equation (2) is known. This ratio is equal to the ratio of the difference obtained by subtracting the x coordinate value of the punching site Q2 from the x coordinate value of the collision site P2 and the difference obtained by subtracting the x coordinate value of the position Q2 ′ from the x coordinate value of the punching site Q2. Thus, the x coordinate value of the punch-out site Q2 may be calculated. Note that FIG. 6 illustrates the case where the collision site is located on the side surface of the host vehicle and the projecting site is located on the rear surface of the host vehicle. Even when the part is located (since the coordinates of the collision part are changed as compared with the case of the collision part P2 and the protrusion part Q2 shown in FIG. 6), the protrusion part can be calculated in the same manner as described above.

  In the above description, the case where the collision site is located on the left side of the host vehicle 11 and the projecting site is located on the right side of the host vehicle 11 has been described. However, the collision site is located on the right side of the host vehicle 11. When the protruding part is located on the left side, the collision part can be calculated in the same manner as described above.

  Returning to the description of FIG. 4, after the protruding portion is calculated in step S <b> 21, the process of step S <b> 22 is executed. In step S22, the degree of injury is calculated based on the collision site and the punching site. In this embodiment, control ECU6 which performs step S22 is equivalent to the injury degree calculation part as described in a claim. Here, in the present embodiment, the degree of injury is calculated based on the combination of the collision site and the punching site and the punching distance from the collision site to the punching site. Hereinafter, an example of a method for calculating the degree of injury will be described with reference to FIG.

  FIG. 7 is a diagram illustrating a correspondence relationship between the combination of the collision site and the punching site and the degree of injury. In the present embodiment, as shown in FIG. 7, the host vehicle 11 is divided into three regions A1 to A3. The front area A <b> 1 is an area on the front side of the cabin of the host vehicle 11. The cabin area A2 is an area in the cabin of the host vehicle 11. The rear region A3 is a region on the rear side of the cabin of the host vehicle 11. The control ECU 6 determines the degree of injury depending on the combination of the collision part and the punching part, that is, in which of the areas A1 to A3 the collision part and the punching part are included. In the present embodiment, the control ECU 6 determines that the level of the injury level is “large” when both the collision site and the ejection site are in the cabin area A2 (combination of the collision site P5 and the ejection site Q5 shown in FIG. 7). To do. In addition, when at least one of the collision part and the protrusion part is in the front region A1 (a combination of the collision part P4 and the protrusion part Q4 shown in FIG. 7), the level of injury is determined as “medium”. When at least one of the collision part and the punching part is in the rear region A3, the level of injury is determined as “medium” or “small”. Here, the level of injury is determined so as to increase as the punching distance increases. Specifically, when the punching distance is equal to or greater than the predetermined distance (a combination of the collision site P6 and the punching site Q6 shown in FIG. 7), the level of injury is determined to be “medium”, and the above-described punching distance is determined in advance. If the distance is shorter than the predetermined distance (a combination of the collision site P7 and the projecting site Q7 shown in FIG. 7), the injury level is determined to be “small”. As described above, the degree of injury can be determined by using the combination of the collision part and the punching part and the punching distance from the collision part to the punching part.

  In the present embodiment, the degree of injury was calculated using the combination of the collision site and the punching site and the punching distance from the collision site to the punching site. In other embodiments, the combination and the punching distance are calculated. The degree of injury may be calculated using only one of these. For example, using only the above combination, the degree of injury is set to “large” when the collision site and the ejection site are located in the cabin area A2, and at least one of the collision site and the ejection site is located in the front area A1. The injury degree may be determined to be “medium” when it is present, and the injury degree may be determined to be “small” in other cases. Further, for example, the degree of injury may be increased as the punching distance is increased by using the punching distance. In the present embodiment, the degree of injury is represented by three levels of “large”, “medium”, and “small”. However, in other embodiments, the degree of injury may be represented by a numerical value.

  Returning to the description of FIG. 4, after the injury degree is calculated in step S22, the process of step S23 is executed. In step S23, the control ECU 6 determines the brake timing based on the degree of injury. In this embodiment, control ECU6 which performs step S23 corresponds to the control part as described in a claim. Specifically, the control ECU 6 calculates a threshold value related to the collision time based on the degree of injury. In this embodiment, control ECU6 memorize | stores beforehand the information (table etc.) which linked | related the injury degree and the threshold value, determines the threshold value from the injury degree with reference to the said information. FIG. 8 is a diagram illustrating a correspondence relationship between the degree of injury and the threshold value. In FIG. 8, a threshold value of “0.9” is associated with the degree of injury “large”, a threshold value of “0.6” is associated with the degree of injury “medium”, and Is associated with a threshold value of “−0.1”. The control ECU 6 determines the threshold based on the correspondence shown in FIG. After the end of step S23, the control ECU 6 ends the brake timing determination process shown in FIG.

  Returning to the description of FIG. 3, the process of step S2 is executed after the brake timing determination process of step S1. In step S2, the control ECU 6 calculates the collision time. In this embodiment, control ECU6 which performs step S2 is equivalent to the collision time calculation part as described in a claim. The collision time is calculated from, for example, the distance between the host vehicle and the other vehicle and the relative speed between the host vehicle and the other vehicle. The distance between the host vehicle and the other vehicle can be calculated from the position of the other vehicle included in the other vehicle information. The relative speed can be calculated from the above-described own vehicle speed and other vehicle speed. Following step S2, the process of step S3 is executed.

  In step S3, the control ECU 6 determines whether or not to start brake control. The determination in step S3 is performed using the threshold value determined in step S1 and the collision time calculated in step S2. That is, when the collision time is equal to or less than the threshold, it is determined that the brake control is started, and when the collision time is larger than the threshold, it is determined that the brake control is not started. When the threshold value is determined to be a negative value, it is determined that the brake control is started after the absolute value of the threshold value has elapsed since the collision was detected. If the determination result of step S3 is affirmative, the process of step S4 is executed. On the other hand, when the determination result of step S3 is negative, the process of step S1 is executed again. Note that the processing loop of steps S1 to S3 is repeatedly executed at a rate of once per predetermined time.

  In step S4, the control ECU 6 starts brake control. In this embodiment, control ECU6 which performs step S4 is equivalent to the control execution part as described in a claim. Specifically, the control ECU 6 instructs the brake ECU 7 to perform brake control. This instruction may instruct a target braking force, or may simply instruct to apply a brake. Specifically, when the degree of injury is “large”, the brake control is performed so that the degree of injury is at least smaller so as to avoid collision if possible. In other words, the brake control is performed so that the straight line connecting the collision site and the punch-out site does not reach at least the cabin area A2 of the own vehicle so as not to be applied to the own vehicle if possible. When the degree of injury is “medium”, the brake control is performed so as to avoid a collision with another vehicle, that is, so that a straight line connecting the collision part and the protruding part is not applied to the own vehicle. In the present embodiment, when the injury degree is “low”, the threshold value is determined to be a negative value (−0.1), so that the brake control is not performed before the collision, and the collision is not performed. The brake control is performed later. This is because, when the degree of injury is “small” (when the collision site and the punching site are the rear region A3), the brake distance becomes longer or the collision site and the punching site are located in the cabin. This is because the degree of injury may increase as a result of the region or the front region A1. The reason why the brake control is performed after the collision is to prevent secondary damage in which the own vehicle colliding with another vehicle collides with another vehicle.

  As described above, since the brake control is started by the process of step S4, even when it is determined that the host vehicle collides with another vehicle (possibly), the collision can be reduced or avoided. it can. In addition, secondary damage due to collision can be prevented. In addition, after brake control is started by step S4, the process of step S1 is performed again. At this time, if the determination result in step S3 is negative after the brake control is started in step S4, the control ECU 6 may stop the brake control. In another embodiment, in step S4, not only brake control but also steering control may be performed, or an airbag operation or a warning to the driver may be performed.

  As described above, according to the present embodiment, the collision mitigation apparatus can calculate the degree of injury more accurately by calculating the degree of injury in consideration of not only the collision site but also the punching site. Furthermore, since the brake timing is determined using the degree of injury, the brake timing can be determined at a more appropriate timing.

  Further, the control ECU 6 estimates the collision site and the punch-out site, and calculates the degree of injury based on the estimation result. Then, the brake timing is determined according to the degree of injury. For example, when the collision part and the punching part are the cabin area A2 of the host vehicle, the control ECU 6 estimates the degree of injury as “large” and sets the threshold value to “0.9”. As a result, the brake control is started when the collision time becomes 0.9 [second] or less. When the collision part and the punching part are the front area A1 of the host vehicle, the control ECU 6 estimates the degree of injury as “medium” and sets the threshold value to “0.6”. As a result, the brake control is started when the collision time becomes 0.6 [seconds] or less. As described above, according to the present embodiment, the brake timing can be determined so as to be earlier as the degree of injury is larger, so the brake timing can be appropriately determined according to the degree of injury. Furthermore, in this embodiment, when the collision part and the punching part are the rear region A3 of the host vehicle and the punching distance is shorter than the predetermined distance, the control ECU 6 estimates the degree of injury as “small” and sets the threshold value. Set to “−0.1”. As a result, the brake control is started at a point 0.1 seconds after the collision. As a result, the degree of injury can be prevented from increasing due to brake control, and secondary damage due to a collision can be prevented.

  In the above embodiment, the degree of injury is calculated from the collision site and the punching site, and the brake timing (the threshold value) is determined from the degree of injury. However, in other embodiments, braking is performed from the collision site and the punching site. The timing may be determined directly.

  Further, in the above embodiment, the injury degree is calculated based on the combination of the collision site and the punching site and the punching distance. However, if the injury level is calculated from the collision site and the punching site, the above embodiment is used. It is not limited. For example, in another embodiment, when another vehicle collides with the own vehicle, the area where the other vehicle intersects with the own vehicle is estimated from the collision site and the punching site, and the degree of injury is determined according to the area. You may make it do.

  Further, in the above embodiment, the brake timing is determined from the collision site and the punching site (degree of injury). However, in the present invention, the control content related to the brake control is determined based on the collision site and the punching site. do it. For example, in another embodiment, the control ECU 6 may determine whether to perform brake control based on the collision part and the protrusion part. Specifically, for example, when the injury level in the above embodiment is “low”, the brake control is not performed, and when the injury level is “high” or “medium”, the brake control is performed. It may be. Further, for example, the control ECU 6 may determine the deceleration rate (brake strength) by the brake control based on the collision site and the punching site. Specifically, for example, the brake strength may be changed when the injury level is “large”, “medium”, and “small” in the above-described embodiment. Thus, the deceleration of the vehicle can be changed according to the collision site and the punching site.

  As described above, the present invention can be used as, for example, a collision reducing device mounted on a vehicle for the purpose of performing more accurate brake control in order to reduce or avoid a collision.

The block diagram which shows the structure of the collision reduction apparatus which concerns on this embodiment. The figure which shows the relationship between the example of three collision states from which an injury degree differs, and the brake timing in the case of each collision state The flowchart which shows the flow of a process of the collision mitigation apparatus shown in FIG. The flowchart which shows the flow of the detailed process of the brake timing determination process (step S1) shown in FIG. The figure for explaining the calculation method of the penetration part The figure for explaining the calculation method of the penetration part The figure which shows the correspondence between the combination of the collision part and the punching part, and the degree of injury The figure which shows the correspondence of injury degree and threshold

Explanation of symbols

1 Radar 2 Radar ECU
3 Steering angle sensor 4 Yaw rate sensor 5 Wheel speed sensor 6 Control ECU
7 Brake ECU

Claims (14)

A collision mitigation device that reduces or avoids collision by performing brake control when it is estimated that the host vehicle collides with another vehicle,
A collision site estimation unit that estimates a collision site that is the position of the host vehicle where the other vehicle is expected to collide,
A collision angle estimator for estimating a collision angle at which the other vehicle collides with the host vehicle;
A projecting site estimation unit that estimates a projecting site when the other vehicle penetrates the host vehicle from the collision site and the collision angle;
A collision mitigation device comprising: a controller that determines the content of brake control based on the collision site and the punching site.   2. The collision mitigation device according to claim 1, wherein the punching site estimation unit estimates a position where a straight line extending from the collision site in a direction determined by the collision angle passes through the host vehicle as the punching site.   The collision reduction device according to claim 1, wherein the control unit determines the content of the brake control by using at least a distance from the collision site to the punching site.   The collision mitigation apparatus according to claim 3, wherein the control unit determines the timing for starting the brake control so that the longer the distance, the faster the timing.   The collision reduction device according to any one of claims 1 to 3, wherein the control unit determines the content of brake control using at least a combination of the collision site and the punching site.   When the collision part and the projecting part are at the cabin position of the own vehicle, the control unit determines the timing to start the brake control, so that at least one of the collision part and the projecting part is ahead of the cabin of the own vehicle. The collision mitigation device according to claim 5, wherein the collision mitigation device is determined to be earlier than the case of the position.   The said control part controls not to perform brake control by a collision on the condition that at least one of the said collision site | part and the said protrusion site | part is a position behind the cabin of the own vehicle at least. The collision mitigation device described in 1.   The collision mitigation apparatus according to claim 7, wherein when the condition is satisfied, the control unit determines timing so as to perform brake control after the collision.   8. The collision mitigation device according to claim 7, wherein the control unit uses as a further condition that a distance from the collision site to the punching site is shorter than a predetermined distance. An injury degree calculation unit that calculates an injury degree that is a degree of injury of the host vehicle when the vehicle collides with the other vehicle based on the collision site and the punching site;
The collision mitigation device according to claim 1, wherein the control unit determines a timing of starting brake control based on the degree of injury.   The collision according to any one of claims 1, 2, 3, and 5, wherein the control unit determines a timing for starting brake control based on the collision site and the punching site. Mitigation device. The control unit calculates a threshold related to a collision time until the own vehicle and the other vehicle collide based on the collision part and the protruding part,
A collision time calculation unit that repeatedly calculates the collision time at predetermined time intervals;
The collision mitigation device according to claim 11, further comprising: a control execution unit that starts brake control when the collision time becomes shorter than the threshold value.   The said control part determines whether brake control is performed based on the said collision site | part and the said punch-out site | part of any one of Claim 1, Claim 2, Claim 3, and Claim 5. Collision mitigation device.   The collision mitigation according to any one of claims 1, 2, 3, and 5, wherein the control unit determines a deceleration rate by brake control based on the collision site and the projecting site. apparatus.

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