JP2017182768A - Collision prevention apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an automatic brake from unnecessarily operating by inhibiting the operation of the brake in the case of a crossing pedestrian ahead of the vehicle itself having no risk of colliding with the vehicle.SOLUTION: A collision prevention apparatus 1 performs: determining, in the state of recognizing a pedestrian crossing ahead of a vehicle itself from an image taken with a camera 2, that a current point in time is operation timing for an automatic brake to be operated on the basis of a vehicular speed detected by a vehicular speed sensor 3 and a vertical distance between the vehicle itself and the pedestrian, and deriving collision prediction time until the vehicle itself collides with the pedestrian from the vehicular speed detected by the vehicular speed sensor 3 and a derived moving speed of the pedestrian in a crossing direction of the pedestrian; and determining that the vehicle itself is predicted to collide with the pedestrian within a first operation-permissible range of a given width that is smaller than an estimated travel route of the vehicle itself from a center thereof on the basis of the derived collision prediction time, and executing control to cause the automatic brake to operate, in the case of determining that a current position of the pedestrian is within a second operation-permissible range of a given distance on left and right sides relative to a center of the estimated travel route of the vehicle itself.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a collision avoidance device that detects a pedestrian in front of the host vehicle and prevents a collision with the detected pedestrian.

  Conventionally, a device has been developed that detects a pedestrian in front of the host vehicle, predicts the pedestrian's movement, and may collide with the host vehicle. There has been proposed one that can accurately determine whether or not a crossing pedestrian in front of the host vehicle may collide with the host vehicle so that the collision can be prevented in advance (see Patent Document 1).

Japanese Patent Laying-Open No. 2015-32154 (see paragraphs 0010 to 0018 and FIGS. 1 to 3)

  By the way, in conventional collision prevention measures with a crossing pedestrian, it is generally performed to determine the possibility of a collision with a crossing pedestrian based on the speed of the crossing pedestrian and the vehicle speed of the own vehicle. When the distance between the vehicle and the host vehicle is large, the pedestrian may move in a different direction that is not a crossing direction, or a crossing that should avoid a collision by misidentifying an obstacle that is not a crossing pedestrian as a pedestrian. In spite of not being a pedestrian, there is a problem that the automatic brake, which is a collision avoidance device, operates unnecessarily and gives the driver a sense of incongruity.

  The present invention accurately detects pedestrians that may collide with the host vehicle among crossing pedestrians in front of the host vehicle, and does not activate the automatic brake when there is no risk of collision, and does not require an automatic brake. The purpose is to prevent the operation in advance.

  In order to achieve the above-described object, a collision avoidance device according to the present invention detects a pedestrian in front of the host vehicle and prevents a collision with the detected pedestrian. Based on the recognition means for recognizing whether the obstacle present ahead is a pedestrian by the image recognition processing, the vehicle speed detection means for detecting the vehicle speed of the host vehicle, the vehicle speed detected by the vehicle speed detection means and the camera image Derivation means for deriving a relative distance between the host vehicle and the pedestrian and a moving speed of the pedestrian in the transverse direction, and automatic braking when reaching an operation timing at which a collision with the obstacle should be avoided. From the braking means to be operated and at least the relative distance by the deriving means, it is determined that the current time point is the operation timing, and the vehicle speed detected by the vehicle speed detecting means and the guide speed are determined. It is determined that a collision between the own vehicle and the pedestrian is predicted within a predetermined width smaller than the vehicle width from the center of the own vehicle based on the moving speed of the vehicle, and the current position of the pedestrian is the own vehicle of the own vehicle And control means for executing control for operating the braking means when it is determined that the position is within a predetermined distance with respect to the estimated course center.

  Further, the vehicle further comprises own lane detecting means for detecting an area of the own lane that is a lane in which the own vehicle is traveling based on the camera image, and the control means is configured to detect at least a current distance from the relative distance by the deriving means. It is determined that the time is the operation timing, and the vehicle and the vehicle are within a predetermined width smaller than the estimated vehicle speed from the center of the vehicle based on the vehicle speed detected by the vehicle speed detection unit and the moving speed by the derivation unit. It is determined that a collision with a pedestrian is predicted, the current position of the pedestrian is determined to be within a predetermined distance with respect to the estimated course center of the own vehicle, and the pedestrian is When it is determined that the vehicle is located within the lane region, control for operating the braking means may be executed (claim 2).

  According to the first aspect of the present invention, it is determined that the current time point is the operation timing of the braking means from at least the relative distance by the deriving means, and the own vehicle is determined from the vehicle speed detected by the vehicle speed detecting means and the moving speed of the pedestrian by the deriving means. If it is determined that a collision between the host vehicle and the pedestrian is predicted within a predetermined range smaller than the vehicle width from the center of the vehicle, and the current position of the pedestrian is located within a predetermined distance with respect to the estimated course center of the host vehicle By recognizing a crossing pedestrian based on the three judgment conditions of judging, when all of these three judgment conditions are satisfied, the pedestrian clearly judges to cross the front of the host vehicle instead of an obstacle. Therefore, it can be determined that a collision with the own vehicle is predicted. Therefore, if the above three determination conditions are satisfied, there is a risk of a collision with a crossing pedestrian, so that a collision with a pedestrian crossing the front of the host vehicle can be prevented by operating the braking means. If one of the three judgment conditions is not satisfied, the braking means can be prevented from being operated unnecessarily, assuming that there is no possibility of a collision with a pedestrian.

  According to the second aspect of the present invention, it is possible to prevent malfunction of the braking means in a situation where the operation of the braking means that a crossing pedestrian is expected to stop at a red signal outside the own lane is unnecessary. . Moreover, the quality of the collision avoidance device can be further improved by preventing such a malfunction.

1 is a block diagram of a first embodiment of a collision avoidance device according to the present invention. It is operation | movement explanatory drawing of 1st Embodiment. It is a flowchart for operation | movement description of 1st Embodiment. It is operation | movement explanatory drawing of 2nd Embodiment of the collision avoidance apparatus which concerns on this invention. It is a flowchart for operation | movement description of 2nd Embodiment.

<First Embodiment>
A first embodiment of a collision avoidance device according to the present invention will be described in detail with reference to FIGS. 1 to 3. Note that front and rear and left and right in the present embodiment mean front and rear and left and right as viewed in a seated state on the seat.

  As shown in FIG. 1, the collision avoidance device 1 includes a camera 2 that captures the front of the host vehicle, a vehicle speed sensor 3 that is a vehicle speed detection unit that detects the vehicle speed of the host vehicle, and an ECU (Electronic Control Unit) having a microcomputer configuration. 4, a brake actuator 5 that applies automatic braking under the control of the ECU 4, and a steering angle sensor 6 that detects the steering angle of the steering.

  The ECU 4 captures a camera image from the camera 2 and performs image recognition processing by so-called pattern recognition by collating image images for collation such as pedestrians, various vehicles and road structures stored in the built-in memory with camera images. , It has a function as a recognition means for recognizing whether an obstacle existing in front of the host vehicle is a pedestrian.

  When the ECU 4 recognizes that the obstacle existing in front of the host vehicle is a pedestrian, the ECU 4 determines the relative distance in the traveling direction between the host vehicle and the pedestrian based on the detected vehicle speed by the vehicle speed sensor 3 and the camera image by the camera 2. (Hereinafter also referred to as a longitudinal distance) and a function as a derivation means for deriving the moving speed of the pedestrian in the transverse direction.

  The operation timing at which the vertical distance between the host vehicle and an obstacle such as a pedestrian is the limit at which the host vehicle can be avoided when the host vehicle is braked (brake) at a predetermined deceleration. The brake actuator 5 is controlled to enable automatic braking, and the function of the ECU 4 and the brake actuator 5 constitute the braking means in the present invention.

  By the way, the ECU 4 performs the following control in order not to activate an unnecessary automatic brake. That is, as shown in FIG. 2, in the state where the pedestrian P crossing the front of the host vehicle C is recognized from the camera image of the camera 2, (1) the vehicle speed detected by the vehicle speed sensor 3, the host vehicle C and the pedestrian P In addition to the vertical distance, the current acceleration / deceleration of the own vehicle C calculated from the detected vehicle speed and the relative speed between the own vehicle C and the pedestrian P are determined to be the operation timing at which the automatic brake should be activated. And (2) a predicted collision time (TTC) until the own vehicle C collides with the pedestrian P from the vertical distance between the own vehicle C and the pedestrian P, the relative speed between the own vehicle C and the pedestrian P, and the like. Based on the derived predicted collision time (TTC), the own vehicle C and the pedestrian P within the first operation permission range W that is a predetermined width smaller than the vehicle width from the center of the own vehicle C shown in FIG. And that the collision is predicted, and ( ) When it is determined that the current position of the pedestrian P is located outside the estimated course L of the host vehicle C of the host vehicle C shown in FIG. In addition, it is assumed that a pedestrian P crossing the front of the host vehicle C may collide with the host vehicle C at a predicted collision position indicated by an X in FIG. 2 derived from the current position, TTC, lateral speed, and the like. Control for operating the brake is executed.

  As described above, when all of the above three determination conditions (1) to (3) that should execute the control for operating the automatic brake are satisfied, the ECU 4 clearly crosses the front of the host vehicle instead of the obstacle. It can be determined that a collision with the own vehicle is predicted, and if the three determination conditions are satisfied, the brake actuator 5 is controlled so that there is a possibility of a collision with a crossing pedestrian. The automatic brake is activated to prevent a collision with a pedestrian crossing the front of the vehicle, while if any one of the three judgment conditions is not established, there is no possibility of a collision with the pedestrian. The brake actuator 5 is controlled to be inactive so that the automatic brake is not operated unnecessarily.

  At this time, the second operation permission range D to be set to the left and right with respect to the estimated course center CL of the own vehicle as a reference when judging whether or not the judgment condition (3) described above is satisfied is the own vehicle It is desirable to vary according to the vertical distance between C and the pedestrian P and the lateral movement speed of the pedestrian P crossing. For example, when the lateral movement speed of the pedestrian P is fast, or when the vertical distance between the host vehicle C and the pedestrian P is long, the pedestrian P may reach the predicted collision position in front of the center of the host vehicle C early. Therefore, the second operation permission range D is widened in order to widen the detection area of the pedestrian P that is a collision avoidance target. On the other hand, when the lateral movement speed of the pedestrian P is slow, or when the vertical distance between the host vehicle C and the pedestrian P is short, the pedestrian P is slow to reach the predicted collision position in front of the center of the host vehicle C. Therefore, it is not necessary to expand the detection area of the pedestrian P that is a collision avoidance target. In addition, it is verified experimentally beforehand how to set the second operation permission range D with respect to the moving speed and the vertical distance of the pedestrian P, and the moving speed and the vertical length of the pedestrian P are verified. The relationship between the distance and the operation permission range D is mapped and stored in the built-in memory of the ECU 4, etc., and the optimum operation permission range D with respect to the current moving speed and vertical distance of the pedestrian P is read and described above (3) It may be used as a reference for comparison of the determination conditions.

  Next, the control operation of the ECU 4 will be described with reference to the flowchart of FIG. Now, as shown in FIG. 3, the ECU 4 determines whether or not the obstacle present in front of the host vehicle is a pedestrian by the image recognition process based on the camera image as described above (step S1). If this determination result is YES, it is determined whether or not the current time point regarding the determination condition (1) described above is the operation timing at which the automatic brake should be operated (step S2).

  If the determination result in step S2 is YES, the process proceeds to the next step S3 on the assumption that the above-described determination condition (1) is satisfied, and the above-described determination (2) is made from the derived collision prediction time (TTC). It is determined whether or not a collision between the host vehicle and a pedestrian is predicted within a first operation permission range W (see FIG. 2) that is a predetermined width smaller than the vehicle width from the center of the host vehicle regarding the conditions. (Step S3).

  If the determination result in step S3 is YES, it is determined that the above-described determination condition (2) is also established, and the process proceeds to the next step S4. It is determined whether or not the pedestrian is located within the permitted operation range D (see FIG. 2) (step S4). If the determination result is YES, the determination condition of (3) described above is satisfied, If all three judgment conditions (1) to (3) are satisfied and it is judged that there is a possibility that the host vehicle and the crossing pedestrian may collide at the collision predicted position indicated by the cross in FIG. Migrate to

  And if the determination result of step S4 is YES, it will be judged in step S5 that it is an automatic brake actuating object (step S5), and if the determination result of step S4 is NO, the determination result of step S1, S2, S3 will be. Together with the case of NO, it is determined that the vehicle is not subject to automatic brake operation (step S6). Thereafter, various switch information such as the vehicle speed by the vehicle speed sensor 3, the direction indicator, the shift range, the steering angle by the steering angle sensor 6, the other system The vehicle side conditions such as the operating state are confirmed to determine whether or not the vehicle side operating conditions are satisfied (step S7). If this determination result is YES, the automatic brake is operated (step S8), and the determination result is If NO, the automatic brake is deactivated (step S9), and then the operation ends.

  Therefore, according to the first embodiment described above, if the three determination conditions (1) to (3) described above are satisfied, it is assumed that there is a risk of a collision with a crossing pedestrian, and by operating the automatic brake, A collision with a pedestrian crossing the front of the host vehicle can be prevented in advance.

  Furthermore, if any one of the three judgment conditions is not satisfied, the braking means can be prevented from being operated unnecessarily because there is no risk of a collision with the pedestrian. When the vehicle is outside the operation permission range D, it is possible to prevent the driver from feeling uncomfortable due to the automatic brake being operated unnecessarily even though there is no risk of collision with the pedestrian.

  In addition, the second operation permission range D of a predetermined distance set to the left and right with respect to the estimated course center CL of the own vehicle, which is the criterion of the determination condition of (3) described above, is defined as the own vehicle C and the pedestrian P. Because it can be changed according to the vertical distance and the moving speed of the pedestrian P crossing, it is possible to narrow down the automatic brake operating conditions for crossing walking cars with different moving speeds and vertical distances, and to improve the accuracy of collision avoidance Can be improved.

Second Embodiment
In the first embodiment described above, the ECU 4 uses the determination conditions (1) to (3) in order to avoid unnecessary automatic brake operation. Good.

  Even when the ECU 4 recognizes a pedestrian forward from the camera image and satisfies all the determination conditions (1) to (3), the automatic brake operation may not be necessary. For example, even if a crossing pedestrian is detected in front of the host vehicle, if the pedestrian's traveling direction signal is a red signal, the lane (own lane) in which the host vehicle travels must be crossed. Without stopping, there is a high probability of stopping. It is highly likely that operating the automatic brake in this situation will be a nuisance.

  Therefore, as shown in FIG. 4, the positional relationship between the area (range) of the lane (own lane) in which the host vehicle is traveling and the crossing pedestrian is added to the determination condition. In the detection of the range of the own lane, the ECU 4 captures the camera image from the camera 2 and detects the white line 7 drawn in the direction parallel to the traveling direction of the host vehicle on both the left and right sides of the traveling direction of the host vehicle. As a method for detecting the white line 7 by the ECU 4, for example, the detected camera image is binarized and then detected by performing edge detection processing. At this time, if the white lines 7 can be detected on both the left and right sides in the traveling direction, if the distance between the white lines 7 (the width LW of the own lane) is a certain width wider than the vehicle width of the own vehicle, the ECU 4 The both white lines 7 are white lines 7 defining the own lane, and an area sandwiched between the two white lines 7 is detected as an area of the own lane. Thus, the function in which the ECU 4 detects the area of the own lane based on the camera image corresponds to the own lane detecting means of the present invention.

  When the ECU 4 satisfies all of the determination conditions (1) to (3), (4) when it is determined that the crossing pedestrian is in the area of the own lane, the ECU 4 performs control for operating the automatic brake. If it is executed and the vehicle is outside the area of the own lane, the control for operating the automatic brake is not executed (undesignated travel mode described later). Note that if the vehicle lane cannot be recognized, the ECU 4 executes control for operating the automatic brake if all of the determination conditions (1) to (3) are satisfied. The detection method of the white line 7 for defining the own lane can be changed as appropriate.

  In the case of left-handed driving, a crossing pedestrian that satisfies all of the determination conditions (1) to (3) stops at a red light on the left side in the traveling direction of the own vehicle. The success or failure of the determination condition (4) may be determined by comparing the positional relationship between the pedestrian positioned on the left side of the lane and the white line 7 on the left side. On the other hand, in the case of right-side traveling, the success or failure of the determination condition (4) may be determined by comparing the positional relationship between the pedestrian located on the right side of the own lane and the white line 7 on the right side. Further, three types of the left traveling mode, the right traveling mode, and the non-designated traveling mode may be provided so that the determination method of success / failure of the determination condition of (4) can be switched.

  Next, the control operation of the ECU 4 of this example will be described with reference to the flowchart of FIG. In addition, about the process of step S1-S4, since it is the same as the process (refer step S1-step S4 of FIG. 3) of above-described 1st Embodiment, description is abbreviate | omitted.

  If the determination result in step S4 is YES, it is determined whether or not a certain lane has been detected (step S10). If this determination is YES, the current position of the pedestrian is within the area of the own lane. Is determined (step S11). If the determination result is YES, it is determined that the vehicle is subject to automatic braking operation (step S5), along with the case where the own lane having a certain width is not detected in step S10 (NO in step S10). On the other hand, if the determination result of step S11 is NO, it is determined that the determination result of steps S1, S2, S3, and S4 is NO and the automatic brake operation non-target object (step S6). After that, vehicle condition such as vehicle speed, direction indicator, shift range and other switch information by vehicle speed sensor 3, steering angle by steering angle sensor 6, operating state of other system, etc. is confirmed and vehicle-side operating condition is satisfied If the determination result is YES, the automatic brake is activated (step S8). If the determination result is NO, the automatic brake is deactivated (step S9), and then the operation ends. To do.

  Therefore, according to the second embodiment described above, it is possible to prevent the automatic brake from malfunctioning in a situation where the operation of the automatic brake is unnecessary, in which the crossing pedestrian is expected to stop at the red signal outside the own lane. Can do. Moreover, the quality of the collision avoidance device 1 can be further improved by preventing such a malfunction.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention.

  For example, the recognition as to whether or not the person is a pedestrian in the above-described embodiment is not limited to the above-described image recognition processing by pattern recognition.

  Further, based on the vehicle speed detected by the vehicle speed sensor 3 and the camera image by the camera 2, the relative distance (vertical distance) in the traveling direction between the host vehicle and the pedestrian and the moving speed of the pedestrian in the transverse direction are derived. The method for deriving the relative distance (vertical distance) and the moving speed of the pedestrian in the transverse direction is not limited to this.

  In the above-described embodiment, the second operation permission range D shown in FIG. 2 is made variable according to the vertical distance between the own vehicle and the pedestrian and the moving speed of the crossing pedestrian. The second operation permission range D may be varied in accordance with the steering operation state based on the steering angle detected by the steering angle sensor. For example, when the steering operation is performed in the left direction, the left side of the host vehicle When the steering operation is performed in the right direction, the operation permission range D on the right side of the host vehicle may be expanded. If it carries out like this, the operating condition of the automatic brake with respect to a crosswalk can be narrowed down according to the operation state of the steering of the own vehicle, and it becomes possible to aim at the improvement of the precision of collision avoidance.

1 ... Collision avoidance device 2 ... Camera (recognition means)
3 ... Vehicle speed sensor (vehicle speed detection means)
4 ... ECU (recognition means, derivation means, braking means, control means, own lane detection means)
5 ... Brake actuator

Claims (2)

In a collision avoidance device that detects a pedestrian in front of the host vehicle and prevents a collision with the detected pedestrian,
Recognizing means for recognizing whether an obstacle existing ahead is a pedestrian by image recognition processing of a camera image in front of the host vehicle;
Vehicle speed detection means for detecting the vehicle speed of the host vehicle;
Deriving means for deriving a relative distance between the host vehicle and the pedestrian and a moving speed in the transverse direction of the pedestrian based on the vehicle speed detected by the vehicle speed detecting means and the camera image;
Braking means for activating an automatic brake when an operation timing to avoid a collision with the obstacle is reached;
At least from the relative distance by the deriving means, it is determined that the current time point is the operation timing, and from the center of the own vehicle from the vehicle speed detected by the vehicle speed detecting means and the moving speed by the deriving means from the estimated course of the own vehicle When it is determined that a collision between the host vehicle and the pedestrian is predicted within a small predetermined width, and the current position of the pedestrian is determined to be within a predetermined distance with respect to the estimated course center of the host vehicle. And a control means for executing control for operating the braking means. Further comprising own lane detection means for detecting an area of the own lane that is the lane in which the own vehicle is traveling based on the camera image;
The control means determines that the current time point is the operation timing from at least the relative distance by the deriving means, and determines from the center of the own vehicle from the vehicle speed detected by the vehicle speed detecting means and the moving speed by the deriving means. It is determined that a collision between the host vehicle and the pedestrian is predicted within a range of a predetermined width smaller than the estimated course of the vehicle, and the current position of the pedestrian is located within a predetermined distance with respect to the estimated course center of the host vehicle. 2. The collision according to claim 1, wherein when the pedestrian determines that the pedestrian is positioned within the area of the own lane by the own lane detecting means, the control for operating the braking means is executed. Avoidance device.

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