JP2009146029A - Traveling safety device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To issue a warning at an appropriate timing, even at an intersection with poor view. <P>SOLUTION: A traveling safety device 1 of a vehicle is provided with an external sensor 11 for detecting an object in the periphery of own vehicle at prescribed time intervals; a relative relation calculating part 21 for calculating the relative relation between own vehicle and the object based on the detection result of the external sensor 11; own vehicle sensor 12 for detecting the traveling state of own vehicle; a TTC calculation part 22 for calculating the time until the object and own vehicle collide, based on the relative relation calculated by the relative relation calculation part 21; and a warning generating device 13 for issuing warning to crews, when the collision time calculated by the TTC calculating part 22 is smaller than the warning decision threshold. This traveling safety device 1 is provided with a visibility estimating part 23 for, when the oncoming vehicle and the preceding vehicle are detected by the external sensor 11, estimating the visibility, when viewing the oncoming vehicle from the driver's position of own vehicle. The warning timing determining part 24 increases the warning decision threshold, according to the decrease in the visibility estimated by the visibility estimation part 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle travel safety device for avoiding a collision between a host vehicle and another vehicle.

  At intersections where there are many blind spots with respect to the driver of the host vehicle, the position and movement of obstacles around the host vehicle are detected. Based on the detected value, the driver's attention to the obstacle is determined. An anti-collision device is known that warns the driver of the host vehicle when estimating and starting the host vehicle with a low degree of attention (estimated by detecting the brake pedal switch OFF). (For example, refer to Patent Document 1).

In addition, when the visibility from the own vehicle is poor, information on the location that is the blind spot of the own vehicle obtained by using the rear camera of the preceding vehicle is acquired via inter-vehicle communication with the preceding vehicle, Accident prevention devices that are used to prevent accidents of the host vehicle are also known (see, for example, Patent Document 2).
JP 2005-173703 A JP 2006-318093 A

  However, in the collision prevention apparatus described in Patent Document 1, even if an alarm is issued, if the driver of the host vehicle does not recognize the object to be alarmed, the operation until the avoidance action is taken after receiving the alarm. There is a possibility that the required time will increase and the avoidance action will be delayed, making collision avoidance difficult. In order to cope with this, if the alarm timing is simply advanced, alarms are frequently issued, and the troublesomeness increases.

  On the other hand, since the accident prevention device described in Patent Document 2 is premised on inter-vehicle communication, it requires enormous costs to introduce communication equipment and infrastructure facilities, and is not used when communication is interrupted. There is a problem of becoming possible. Moreover, since it is assumed that the system is mounted not only on the own vehicle but also on the preceding vehicle, there is a problem that the effect cannot be obtained only by installing this system on the own vehicle.

  Accordingly, the present invention provides a vehicle travel safety device that can complete a system only with its own vehicle and can issue an alarm at an accurate timing even at an intersection with poor visibility.

The vehicle travel safety device according to the present invention employs the following means in order to solve the above problems.
The invention according to claim 1 is based on an object detection means (for example, an external sensor 11 in an embodiment described later) for detecting an object around the own vehicle at a predetermined time interval, and the detection result of the object detection means. A relative relationship calculating means for calculating a relative relationship between the vehicle and the object (for example, a relative relationship calculating unit 21 in the embodiment described later) and a traveling state detecting means for detecting the traveling state of the host vehicle (for example, in an embodiment described later). Collision time calculation means (for example, TTC calculation in an embodiment to be described later) for calculating the time until the object and the own vehicle collide based on the relative relationship calculated by the own vehicle sensor 12) and the relative relationship calculation means. Unit 22) and alarm means (for example, alarming an occupant when the collision time calculated by the collision time calculation means is smaller than a predetermined value (alarm determination threshold)) In a travel safety device for a vehicle (for example, a travel safety device 1 in an embodiment to be described later) including an alarm generation device 13 and an alarm timing determination unit 24) in the embodiment to be described, the oncoming vehicle and the preceding vehicle are detected by the object detection means. When a vehicle is detected, the vehicle is provided with visibility estimating means for estimating the visibility when the oncoming vehicle is viewed from the driver position of the host vehicle (for example, the visibility estimation unit 23 in an embodiment described later), The alarm means increases the predetermined value (alarm determination threshold) in accordance with a decrease in visibility estimated by the visibility estimation means.
By comprising in this way, the timing which performs an alarm according to the fall of visibility can be advanced.

The invention according to claim 2 is the invention according to claim 1, wherein a line segment connecting each of the left and right end points in the vehicle width direction of the oncoming vehicle and the viewpoint position of the driver of the vehicle is a first line segment and A line segment calculating means (for example, a line segment calculating unit 25 in an embodiment to be described later) that calculates a line segment connecting the left and right end points of the preceding vehicle as a third line segment, An intersection calculation means (for example, an intersection calculation unit 26 in an embodiment described later) that calculates the intersection of each of the first and second line segments and the third line segment as the first intersection and the second intersection; The visibility estimation means includes a distance between the first intersection and a host vehicle side end point among left and right end points of the preceding vehicle, and a host vehicle side end point between the second intersection point and the left and right end points of the preceding vehicle. To estimate visibility based on the distance of And butterflies.
By comprising in this way, visibility can be estimated exactly based on the positional relationship of the own vehicle, an oncoming vehicle, and a preceding vehicle.

  According to the invention which concerns on Claim 1, the timing which performs a warning according to the fall of visibility can be advanced. Therefore, since it is easy to be warned according to the decrease in visibility, the delay of avoidance action for the warning that occurs when the driver is not aware of the oncoming vehicle is compensated, and the warning is generated at a timing that is useful and not bothersome. be able to.

  According to the invention which concerns on Claim 2, visibility can be estimated exactly based on the positional relationship of the own vehicle, an oncoming vehicle, and a preceding vehicle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a vehicle travel safety device according to the present invention will be described below with reference to the drawings of FIGS.
As shown in FIG. 1, a vehicle travel safety device 1 in this embodiment includes an external sensor (object detection means) 11, a host vehicle sensor (travel state detection means) 12, an alarm generation device (alarm means) 13, and electronic control. Device 20.

  The external sensor 11 is configured by a millimeter wave band radar device, a laser radar device using a wavelength band near the infrared light band, an image recognition device using one or more camera devices, or a combination thereof. The object information (position, speed, traveling direction, size, etc.) around the host vehicle is detected at a predetermined time interval (for example, 100 msec). Further, the external sensor 11 recognizes an object moving in the direction approaching the host vehicle as an oncoming vehicle based on the object information around the host vehicle, and causes an obstacle when the driver of the host vehicle visually recognizes the oncoming vehicle. Recognize the preceding vehicle. The external sensor 11 outputs the detection result to the electronic control unit 20.

  The own vehicle sensor 12 includes sensors for detecting information on the own vehicle such as the vehicle speed, the steering amount, the accelerator opening degree, the brake pedal switch ON / OFF, the blinker switch ON / OFF, and the like. Is output to the electronic control unit 20. It is possible to estimate the yaw rate that will occur in the host vehicle in the future based on the steering amount, and it is possible to estimate the acceleration / deceleration that will occur in the host vehicle in the future based on the accelerator opening and the ON / OFF state of the brake pedal switch. In addition, the information on the host vehicle may be detected directly from each sensor, or may be acquired via various ECUs or in-vehicle LANs mounted on the host vehicle.

  The alarm generation device 13 is a device that issues an alarm to an occupant (especially a driver) of the host vehicle. For example, a buzzer that emits an alarm sound or a synthesized sound in response to a control signal output from the electronic control device 20 or It can be configured from a speaker, a display device for displaying an alarm, or the like. The alarm generator 13 prompts the driver of the host vehicle to avoid contact by generating an alarm.

  Based on various information on the oncoming vehicle and the preceding vehicle input from the external sensor 11 and various information on the own vehicle input from the own vehicle sensor 12, the electronic control unit 20 makes contact with the own vehicle and the oncoming vehicle. Whether or not the driver of the host vehicle needs to be able to estimate the visibility of the oncoming vehicle, determine the timing for warning based on these, and whether or not the driver of the host vehicle needs to be warned Is output, an alarm command is output to the alarm generation device 13.

The electronic control unit 20 includes a relative relationship calculation unit (relative relationship calculation unit) 21, a TTC calculation unit (collision time calculation unit) 22, a visibility estimation unit (visibility estimation unit) 23, and an alarm timing determination unit (alarm). Means) 24.
The relative relationship calculation unit 21 is based on the oncoming vehicle information (position, speed, traveling direction, size) input from the external sensor 11 and the own vehicle information (position, speed, traveling direction) input from the own vehicle sensor 12. Thus, the courses of the host vehicle and the oncoming vehicle are predicted, and the relative distance and the relative speed between the host vehicle and the oncoming vehicle are calculated and output to the TTC calculation unit 22.

  The TTC calculation unit 22 determines whether or not there is a possibility that the host vehicle and the oncoming vehicle are in contact based on the predicted course, the relative distance, and the relative speed of the host vehicle and the oncoming vehicle input from the relative relationship calculation unit 21. When there is a possibility of the contact, the time until contact (that is, the collision time TTC) is calculated and output to the alarm timing determination unit 24.

  The visibility estimation unit 23 includes a line segment calculation unit (line segment calculation unit) 25 and an intersection point calculation unit (intersection point calculation unit) 26, and information (position and size) of the oncoming vehicle and the preceding vehicle input from the external sensor 11. ) To estimate the visibility of the oncoming vehicle as viewed from the driver of the host vehicle, and output the estimation result to the alarm timing determination unit 24.

  More specifically, the line segment calculation unit 25 uses, as the first line segment and the second line segment, line segments connecting the left and right end points in the vehicle width direction of the oncoming vehicle and the viewpoint position of the driver of the host vehicle. While calculating, the line segment which connects the left and right end points of a preceding vehicle is calculated as a 3rd line segment. The intersection calculation unit 26 calculates intersections between the first line segment and the second line segment, respectively, and the third line segment as the first intersection point and the second intersection point. The visibility estimating unit 23 then determines the distance between the first intersection and the own vehicle side end point of the left and right end points of the preceding vehicle, and the own vehicle side end point of the second intersection point and the left and right end points of the preceding vehicle. Visibility is estimated on the basis of the distance. The visibility estimation process will be described in detail later.

  The warning timing determination unit 24 performs a warning based on the visibility input from the visibility estimation unit 23, the collision time TTC input from the TTC calculation unit 22, and the vehicle speed of the host vehicle input from the host vehicle sensor 12. Is output to the alarm generation device 13.

Next, the visibility calculation process for visibility estimation executed by the visibility estimation unit 23 will be described according to the flowchart of FIG. 2 with reference to the model diagram of FIG.
The visibility calculation processing routine shown in the flowchart of FIG. 2 is repeatedly executed at regular intervals by the electronic control device 20.

  First, in step S01, end points pb_max and pb_min in the vehicle width direction of the oncoming vehicle B are detected. In addition, when only one end point of the oncoming vehicle B can be detected by the external sensor 11, the vehicle type (truck, ordinary passenger car, small car, etc.) is estimated from the characteristic part of the oncoming vehicle B detected by the external sensor 11, A position spaced from the detected one end point by the vehicle width dimension of the vehicle type is estimated as the other end point of the oncoming vehicle B.

Next, in step S02, the viewpoint of the driver of the host vehicle A is set to pd.
Next, in step S03, the driver of the own vehicle A sets the oncoming vehicle B as an object that overlaps with the triangles having the vertexes pb_max and pb_min of the oncoming vehicle B and the viewpoint pd of the driver of the own vehicle A as vertices. As the preceding vehicle C that becomes an obstacle when visually recognizing, the end points pc_max and pc_min in the vehicle width direction of the preceding vehicle C are detected.

  Next, in step S04, a straight line (third line segment) L3 that connects the end points pc_max and pc_min of the preceding vehicle C, and a straight line that connects the viewpoint pd of the driver of the host vehicle A and one end point pb_max of the oncoming vehicle B. (First line segment) L1, intersection points of a straight line (second line segment) L2 connecting the viewpoint pd of the driver of the host vehicle A and the other end point pb_min of the oncoming vehicle B are a first intersection point pv_max and a second intersection point, respectively. pv_min is detected.

Next, in step S05, the length of the line segment connecting the end point pc_min on the side close to the host vehicle A among the end points of the preceding vehicle C and the second intersection point pv_min (that is, the linear distance between pc_min and pv_min) dc, The length of the line segment connecting the first intersection point pv_max and the second intersection point pv_min (that is, the linear distance between pv_max and pv_min) dv is calculated.
Next, in step S06, the ratio dc / dv of the lengths of the two line segments is calculated and output as the visibility degree, and the execution of this routine is temporarily terminated.
That is, the smaller the value of the visibility frequency dc / dv (closer to 0), the lower the visibility for the oncoming vehicle B, and the larger the value of the visibility frequency dc / dv, the higher the visibility for the oncoming vehicle B. It becomes.
When the visibility frequency is calculated in this way, the visibility can be accurately estimated based on the positional relationship between the host vehicle, the oncoming vehicle, and the preceding vehicle.

Next, alarm control in this embodiment will be described with reference to the flowchart of FIG.
First, in step S101, own vehicle information (vehicle speed, steering amount, accelerator opening, brake pedal switch ON / OFF, blinker switch ON / OFF, etc.) is acquired from the own vehicle sensor 12.
Next, the process proceeds to step S102, and preceding vehicle information (position, speed, traveling direction, size, etc.) and oncoming vehicle information (position, speed, traveling direction, size, etc.) are acquired from the external sensor 11.
Next, the process proceeds to step S103, where the course (trajectory) of the host vehicle is predicted based on the host vehicle information acquired in step S101, and the path (trajectory) of the oncoming vehicle is determined based on the oncoming vehicle information acquired in step S102. Predict.

Next, the process proceeds to step S104, where it is determined whether there is a possibility that the own vehicle and the oncoming vehicle are in contact with each other based on the predicted course and relative speed of the own vehicle and the oncoming vehicle, that is, whether the collision time TTC can be calculated. To do.
If the determination result in step S104 is “NO” (TTC calculation is impossible), there is no possibility that the host vehicle and the oncoming vehicle will come into contact with each other, so the execution of this routine is temporarily terminated.
If the determination result in step S104 is “YES” (TTC can be calculated), the process proceeds to step S105, and the time until the host vehicle and the oncoming vehicle come into contact (collision time TTC) is calculated.
Next, proceeding to step S106, the visibility calculation process described above is executed to calculate the visibility frequency.

  Next, it progresses to step S107 and it is determined whether the visibility frequency calculated by step S106 is smaller than the preset threshold value Vis. Here, the threshold Vis is a threshold for determining whether or not the driver of the host vehicle has good visibility with respect to the oncoming vehicle. When the visibility frequency is smaller than the threshold Vis, the visibility is low and the visibility is low. When the frequency is equal to or higher than the threshold Vis, it is determined that the visibility is high.

If the determination result in step S107 is “NO” (visibility level ≧ Vis), the process proceeds to step S108, and the collision time TTC calculated in step S105 is smaller than the preset first alarm determination threshold value TTC1. It is determined whether or not. Here, the first warning determination threshold value TTC1 is a threshold value for determining whether or not to warn the passenger of the own vehicle of the possibility of contact with the oncoming vehicle in a situation where the visibility is relatively high. is there. The first warning determination threshold value TTC1 is set to a time (for example, 5 seconds) at which the driver will not feel troublesome even if an alarm is generated.
If the determination result in step S108 is "YES", the collision time TTC is shorter than the first alarm determination threshold value TTC1, so the process proceeds to step S109, an alarm is issued, and the execution of this routine is temporarily terminated.

  On the other hand, if the determination result in step S107 is “YES” (visibility level <Vis), the process proceeds to step S110, and the second alarm determination threshold value TTC2 in which the collision time TTC calculated in step S105 is preset. Or less. Here, the second alarm determination threshold value TTC2 is a threshold value for determining whether or not to warn the passenger of the own vehicle of the possibility of contact with the oncoming vehicle under a low visibility situation. The second alarm determination threshold value TTC2 is set to a value (for example, 10 seconds) that is larger than the first alarm determination threshold value TTC1 and smaller than the time during which it is possible to determine that the possibility of a collision is extremely low at the present time. (TTC2> TTC1). In other words, in a situation where visibility is low, it is highly likely that the driver of the own vehicle has overlooked the oncoming vehicle. In this case, by selecting the second warning determination threshold value TTC2 having a long time, It is possible to issue an alarm early.

  If the determination result in step S110 is “YES” (TTC <TTC2), the collision time TTC is shorter than the second alarm determination threshold value TTC2, so the process proceeds to step S109 to issue an alarm and execute this routine. Exit once. In this way, an alarm is issued earlier than usual (than the first alarm determination threshold value TTC1), so that even if the driver of the own vehicle overlooks the oncoming vehicle, the driver of the own vehicle has a margin. It is possible to take evasive action with.

  On the other hand, if the determination result in step S108 is “NO” (TTC ≧ TTC1), or if the determination result in step S110 is “NO” (TTC ≧ TTC2), the vehicle is in contact with the oncoming vehicle. It is determined that there is sufficient time until this is done and it is not necessary to issue an alarm, and the execution of this routine is temporarily terminated.

Next, referring to FIG. 5, in the situation where the oncoming vehicle goes straight toward the intersection and is approaching, the traveling safety device according to the present invention is exemplified by a case where the own vehicle turns right at the intersection following the preceding vehicle. And a conventional travel safety device will be described in comparison.
In the state shown in FIG. 5A, the external sensor 11 of the host vehicle A-1 detects the oncoming vehicle B-1, but the driver of the host vehicle A is in the blind spot of the preceding vehicle C-1. Therefore, the oncoming vehicle B-1 cannot be visually recognized.

Conventionally, at the time point shown in FIG. 5A, since the collision time TTC until the host vehicle A-1 comes into contact with the oncoming vehicle B-1 is longer than the warning determination threshold, no warning is given.
Therefore, when the driver determines that there is no danger and turns the host vehicle A-2 right after the preceding vehicle C-2, as shown in FIG. Approaches the host vehicle A-2, and the collision time TTC is less than or equal to the alarm determination threshold value, and an alarm is issued. However, at the time shown in FIG. 5B, the visibility of the oncoming vehicle B-2 is low from the driver of the own vehicle A-2, and the driver of the own vehicle A-2 is aware of the oncoming vehicle B-2. If the braking of the host vehicle A-2 is started immediately after receiving the warning, the braking cannot be started immediately even if the warning is received, even though it is a timing at which contact with the oncoming vehicle B-2 can be avoided. Can be considered.
Therefore, conventionally, as shown by a broken line in FIG. 5C, there is a possibility that the host vehicle A-4 and the oncoming vehicle B-3 come into contact with each other.

  In this way, conventionally, when the visibility from the host vehicle to the oncoming vehicle is low, it takes a long time from the generation of the alarm to the transition to the contact avoidance action. The effect of promoting behavior was impaired.

  On the other hand, in the travel safety device of the present invention, when the visibility frequency is smaller than the threshold value Vis at the time shown in FIG. 5A, the host vehicle A-1 contacts the oncoming vehicle B-1. Even if the collision time TTC until this is not smaller than the first warning determination threshold value TTC1, if it is smaller than the second warning determination threshold value TTC2, a warning is issued to the driver of the host vehicle A-1. Therefore, even if the driver of the own vehicle A-1 is not aware of the oncoming vehicle B-1 at the time shown in FIG. 5 (A), be careful of the driver of the own vehicle by issuing an alarm earlier than before. Even when the own vehicle A-2 makes a right turn following the preceding vehicle C-2 as shown in FIG. 5 (B), at the time shown in FIG. The driver of the vehicle A-2 can take a contact avoidance action by stepping on the brake pedal. As a result, as shown in FIG. 5 (C), the host vehicle A-3 can stop before contacting the oncoming vehicle B-3, and contact can be avoided.

  It should be noted that whether or not an alarm is possible is determined using the second warning determination threshold value TTC2 as a threshold value only when the visibility frequency is lower than the threshold value Vis and the visibility frequency is equal to or higher than the threshold value Vis. Is high, the first alarm determination threshold value TTC1 smaller than the second alarm determination threshold value TTC2 is used as a threshold value to determine whether or not an alarm is possible. The alarm does not feel annoying.

  As described above, according to the traveling safety device for a vehicle of this embodiment, an alarm is easily performed according to a decrease in visibility. Therefore, avoidance of an alarm generated when the driver is not aware of the oncoming vehicle. Action delays can be compensated, and an alarm can be generated at a useful and non-intrusive timing.

[Other Examples]
The present invention is not limited to the embodiment described above.
For example, in the above-described embodiment, the visibility is divided into two levels, the first alarm determination threshold value TTC1 is selected when the visibility is high, and the second alarm determination threshold value TTC2 is selected when the visibility is low. However, it is also possible to divide the visibility into, for example, three stages of high, medium, and low, or more than that, and select a warning determination threshold value that gradually increases as the visibility decreases.

It is a block diagram in the Example of the traveling safety device of the vehicle which concerns on this invention. It is a flowchart which shows the visibility calculation process in an Example. It is a model figure explaining the said visibility calculation. It is a flowchart which shows the alarm control in an Example. It is a figure explaining the alarm timing in case the own vehicle turns right at the intersection.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle travel safety device 11 External sensor (object detection means)
12 Own vehicle sensor (running state detection means)
13 Alarm generator (alarm means)
21 Relative relationship calculation unit (relative relationship calculation means)
22 TTC calculation unit (collision time calculation means)
23 Visibility estimation part (visibility estimation means)
24 Alarm timing determination unit (alarm means)
25 Line segment calculation unit (line segment calculation means)
26 Intersection calculator (intersection calculator)

Claims (2)

Object detection means for detecting an object around the host vehicle at a predetermined time interval;
A relative relationship calculating means for calculating a relative relationship between the vehicle and the object based on a detection result of the object detecting means;
Traveling state detection means for detecting the traveling state of the host vehicle;
A collision time calculating means for calculating a time until the object and the host vehicle collide based on the relative relation calculated by the relative relation calculating means;
Warning means for warning a passenger when the collision time calculated by the collision time calculation means is smaller than a predetermined value;
In a vehicle travel safety device comprising:
When an oncoming vehicle and a preceding vehicle are detected by the object detecting means, the vehicle includes a visibility estimating means for estimating the visibility when the oncoming vehicle is viewed from the driver position of the own vehicle,
The vehicle safety device according to claim 1, wherein the warning means increases the predetermined value in accordance with a decrease in visibility estimated by the visibility estimation means. A line segment connecting each of the left and right end points in the vehicle width direction of the oncoming vehicle and the viewpoint position of the driver of the own vehicle is calculated as a first line segment and a second line segment, and the left and right end points of the preceding vehicle are calculated. A line segment calculating means for calculating a connecting line segment as a third line segment;
Intersection calculating means for calculating an intersection of each of the first line segment and the second line segment and the third line segment as a first intersection point and a second intersection point;
The visibility estimation means includes a distance between the first intersection and a host vehicle side end point among left and right end points of the preceding vehicle, and a host vehicle side end point between the second intersection point and the left and right end points of the preceding vehicle. The travel safety device for a vehicle according to claim 1, wherein the visibility is estimated based on the distance.

Images