JP2012168811A - Following vehicle collision warning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a following vehicle collision warning device which can notify a driver of another vehicle of a risk of collision at appropriate timing.SOLUTION: A following vehicle collision warning device comprises: detection means for detecting another vehicle following the own vehicle to output information indicating that the another vehicle has been detected; notification means for notifying at least the another vehicle that the another vehicle is approaching the own vehicle; and control means for controlling a state of notification performed by the notification means by controlling the notification means. Also, based on information which is output from the detection means to indicate detection of the another vehicle, the control means determines a degree of proximity between the own vehicle and the another vehicle and also estimates collision avoidance performance of the another vehicle, to control the notification means according to the degree of proximity and the collision avoidance performance.

Description

  The present invention relates to a rear vehicle collision warning device, and more particularly to a rear vehicle collision warning device mounted on a vehicle.

  Conventionally, it is installed in the host vehicle that can detect other vehicles approaching from the rear of the host vehicle and can warn the driver of other vehicles when the other vehicle is in danger of colliding with the host vehicle. A rear vehicle collision warning device is known.

  Specifically, the rear vehicle collision warning device detects other vehicles behind the host vehicle by using a rear radar or a rear camera mounted on the host vehicle. The rear vehicle collision warning device is, for example, when the risk of collision between the detected other vehicle and the host vehicle is high, that is, when the risk of the rear other vehicle colliding with the host vehicle is high. The tail lamp and the hazard lamp of the own vehicle are turned on and blinked to warn the driver of the other vehicle. In addition, there exists a technique currently disclosed by patent document 1, for example as an example of such a back vehicle collision warning apparatus.

German Patent Application Publication No. 102004062497A1

  By the way, the conventional rear vehicle collision warning device including the technique disclosed in Patent Document 1 has the following problems.

  For example, a case is assumed where another vehicle behind the host vehicle is likely to collide with the host vehicle. In this case, the rear vehicle collision warning device provided in the host vehicle lights and blinks the tail lamp of the host vehicle and notifies the other vehicle behind the host vehicle of the risk of collision. Then, the driver of the other vehicle behind the subject vehicle who senses the danger of the collision avoids the collision by stepping on the brake or operating the steering wheel.

  However, if the driver of the rear vehicle who senses the danger of a collision by stepping on or flashing the tail lamp of the vehicle in front (the host vehicle) depresses the braking acceleration depending on the vehicle type, more specifically the vehicle weight. (Sometimes described as deceleration G). In other words, for example, when the driver's braking force is constant, the deceleration acceleration of the vehicle is inversely proportional to the vehicle weight, so a large vehicle (such as a truck) has a small deceleration acceleration, and conversely, a small vehicle (such as a light vehicle) has a deceleration acceleration. Becomes larger.

  Therefore, when the tail lamp of the own vehicle is turned on and flashed to notify the other vehicle behind the own vehicle of the danger of a collision, when the timing of the notification is constant assuming an ordinary passenger car, In the case of large vehicles (such as trucks), notification is delayed. In other words, in the case of a large vehicle, since the deceleration acceleration is small, it must be notified early.

  On the other hand, when the other vehicle behind the host vehicle is a small vehicle (such as a light vehicle), the notification timing is early. In other words, in the case of a small vehicle (such as a light vehicle), since the deceleration acceleration is large, it is not necessary to notify the user too early.

  That is, when it is determined that there is a risk that another vehicle behind the host vehicle collides with the host vehicle, if there is no change in the timing of an alarm (notification) performed on the other vehicle, the other vehicle behind the host vehicle An alarm delay may occur in the case of a large vehicle, and an early warning will occur if the other vehicle behind the host vehicle is a small vehicle.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rear vehicle collision warning device capable of notifying a driver of another vehicle of the danger of a collision at an appropriate timing. is there.

  In order to achieve the above object, the present invention employs the following configuration. That is, the present invention is a rear vehicle collision warning device that is mounted on the host vehicle and notifies the approach of the vehicle. The rear vehicle collision warning device detects other vehicles behind the own vehicle, outputs detection information indicating that the other vehicles are detected, and at least the other vehicle is approaching the own vehicle. Informing means for informing the other vehicle, and control means for controlling the informing means to control the manner of informing performed by the informing means. Further, the control means judges the degree of approach between the host vehicle and the other vehicle based on the information indicating that the other vehicle output from the detecting means has been detected, and estimates the collision avoidance performance of the other vehicle, and determines the degree of approach and the collision avoidance. Control according to performance is performed with respect to an alerting | reporting means.

  The second invention is characterized in that, in the first invention, the control means performs notification by controlling the notification means when the degree of approach exceeds a reference determined according to the collision avoidance performance.

  According to a third invention, in the first or second invention, the collision avoidance performance of the other vehicle estimated by the control means is calculated based on information indicating that the other vehicle output from the detection means is detected. It is estimated by the size or shape of another vehicle.

  According to a fourth invention, in the first or second invention, the control means calculates a relative speed and a relative distance of the other vehicle with respect to the own vehicle based on information indicating that the other vehicle output from the detection means has been detected. The degree of approach is determined based on the relative speed and the relative distance.

  A fifth invention is characterized in that, in the second invention, when the control means determines that the reference is exceeded, the control means controls the notification means and further notifies the passenger of the own vehicle.

  In a sixth aspect based on the first aspect, the detection means is at least one of a radar device and a camera. Further, the notifying means is at least one of a direction indicator and a tail lamp mounted on the host vehicle.

  According to the first aspect of the present invention, it is possible to provide a rear vehicle collision warning device that can notify a driver of another vehicle of the danger of a collision at an appropriate timing. That is, since the notification is controlled according to the collision avoidance performance of the other vehicle, no alarm delay or early warning occurs.

  According to the second aspect of the invention, the control means performs the notification by controlling the notification means when the degree of approach exceeds a reference determined according to the collision avoidance performance. That is, in other words, the reference is determined according to the collision avoidance performance of the other vehicle estimated by the control means, and the reference differs depending on the collision avoidance performance of the other vehicle estimated by the control means. Therefore, for example, in the case of other vehicles having inferior collision avoidance performance compared to ordinary vehicles, the notification timing can be advanced, and in the case of other vehicles having superior collision avoidance performance compared to ordinary vehicles, the notification timing can be delayed. As a result, there will be no alarm delay or early warning.

  According to the third aspect of the invention, for example, the collision avoidance performance can be estimated by a simple method such as calculating the vehicle width of another vehicle based on information from a camera or a radar device.

  According to the fourth aspect, for example, the degree of approach can be determined based on the relative speed and the relative distance based on information from the camera and the radar device.

  According to the fifth aspect of the invention, the driver of the host vehicle can know in advance that the vehicle behind the host vehicle is too close to the host vehicle, and that the possibility of a collision is high. Drivers can prevent dangers by increasing the distance between vehicles behind them.

  According to the sixth aspect, the winker or tail lamp mounted on the vehicle can be used as the notification means. In addition, if a so-called parking assistance system or the like that can smoothly park in the back by detecting an obstacle behind the host vehicle with a camera or a radar device, the camera is installed. A radar device can also be used. That is, it is not necessary to separately install a detection unit and a notification unit in the host vehicle, and thus an increase in cost can be suppressed.

Block diagram showing an example of the configuration of a rear vehicle collision warning device The figure which shows an example of the flow of the process performed in control ECU1 of the back vehicle collision warning apparatus which concerns on one Embodiment. An image behind the host vehicle captured by the camera 2 Diagram showing the difference in vehicle width depending on the vehicle type (A) Risk level table (normal car) (B) Risk level table (large vehicle) (C) Risk level table (small car)

  When the rear vehicle collision warning device according to the present invention notifies the other vehicle behind the vehicle equipped with the rear vehicle collision warning device that the vehicle is approaching the vehicle equipped with the rear vehicle collision warning device. The collision avoidance performance of the other vehicle behind is estimated based on the size of the other vehicle, for example. And the back vehicle collision warning device which concerns on this invention changes the timing to alert | report (alarm) according to the estimated collision avoidance performance of the other vehicle.

  Hereinafter, a rear vehicle collision alarm device according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an example will be described in which the rear vehicle collision warning device is mounted on a vehicle (specifically, a general passenger car is assumed and hereinafter referred to as a host vehicle).

  FIG. 1 is a block diagram illustrating an example of a configuration of a rear vehicle collision warning device.

  In FIG. 1, the rear vehicle collision warning device includes a control ECU (Electrical Control Unit) 1. A camera 2, a radar device 3, a vehicle information acquisition device 4, a safety device 5 and the like are connected to the control ECU 1.

  The control ECU 1 controls the safety device 5 based on information from a camera 2, a radar device 3, a vehicle information acquisition device 4 and the like, which will be described later, and prompts the driver of the host vehicle, particularly the driver behind the vehicle, to call attention.

  More specifically, based on information from the camera 2 and the radar device 3 described later, the control ECU 1 may cause another vehicle behind the host vehicle not too close to the host vehicle or may collide with the host vehicle. The vehicle type of the other vehicle behind the host vehicle is determined, the safety device 5 is controlled, and notification according to the vehicle type is made (details of the operation of the control ECU 1 are described later in a flowchart). Explanation).

  Returning to the description of FIG. 1, the camera 2 is, for example, a CCD camera, a CMOS camera, an infrared camera, or the like, and is installed in the rear part of the host vehicle to capture the rear of the host vehicle. And the camera 2 images the back of the own vehicle at predetermined time intervals, for example, and outputs the captured image to the control ECU 1.

  Specifically, the radar device 3 is, for example, a millimeter wave radar device, a laser radar device, or the like. The radar device 3 is installed at the rear of the host vehicle, irradiates electromagnetic waves toward the rear outer side of the host vehicle, and monitors the surroundings behind the host vehicle. Specifically, the radar apparatus 3 irradiates electromagnetic waves toward the periphery behind the host vehicle, and detects a target (specifically, another vehicle behind the host vehicle) existing within the detection range of the radar apparatus 3. To do. The radar device 3 detects, for example, other vehicles existing behind and behind the host vehicle, and outputs a signal indicating the target to the control ECU 1.

  Although the camera 2 and the radar device 3 are installed at predetermined positions behind the host vehicle as described above, by detecting an obstacle behind the host vehicle with the camera or the radar device, For example, when a so-called parking assist system or the like that can smoothly park in the back is mounted on the host vehicle, the camera and the radar device are used as the camera 2 and the radar device in the rear vehicle collision warning device according to the present embodiment. 3 may be used.

  Returning to the description of FIG. 1, the vehicle information acquisition device 4 acquires information related to traveling of the host vehicle. An example of the vehicle information acquisition device 4 is a vehicle speed detection device that detects the vehicle speed when the host vehicle is traveling.

  The safety device 5 will be described in detail later, but when the own vehicle and another vehicle traveling behind the own vehicle are too close according to an instruction from the control ECU 1, or when the risk of collision is high For example, alerts are given to other vehicles traveling behind the host vehicle, and alerts are also made to the driver of the host vehicle.

  In addition, the safety device 5 is designed to prevent occupant protection and collision conditions in order to reduce damage to the occupant of the own vehicle when a collision between the own vehicle and another vehicle traveling behind the own vehicle cannot be avoided. Various devices for mitigating are also included. Hereinafter, the operations performed by the safety device 5 are collectively referred to as safety measures.

  In the following description, unless otherwise specified, the other vehicle traveling behind the host vehicle is simply referred to as another vehicle.

  Here, an example of a device constituting the safety device 5 will be described.

  As shown in FIG. 1, the safety device 5 of the rear vehicle collision warning device according to the present embodiment includes an outside display device 51 and an inside display device 52 as an example.

  Specifically, the vehicle exterior display device 51 indicates a red-colored marker lamp (a so-called tail lamp) attached to the rear portion of the host vehicle in order to indicate the presence of the host vehicle in another vehicle. The vehicle exterior display device 51 also indicates signal lights (so-called blinkers) mounted on the front and rear surfaces of the host vehicle in order to blink the traveling direction change.

  Further, the winker that is the outside display device 51 in the rear vehicle collision warning device according to the present embodiment refers to a winker that is mounted on the rear of the host vehicle, in particular. Further, the display device for indicating the presence of the host vehicle in the other vehicle is not limited to the above-described tail lamp or winker. It is not a thing.

  Specifically, the in-vehicle display device 52 is, for example, a liquid crystal display, a light-emitting diode (light emitting diode) provided at a position (such as an instrument panel in front of the driver's seat) that is visible to the driver seated in the driver's seat of the host vehicle. LED) and a display medium such as an organic EL display. The in-vehicle display device 52 is provided with a half mirror (reflection glass) on a part of the windshield in front of the driver's seat, and a head-up display that displays a virtual image such as information on the half mirror in a fluorescent manner. Other display devices may be used.

  Note that the safety device 5 of the rear vehicle collision warning device according to the present embodiment includes a warning device 53 as an example. Specifically, the alarm device 53 is, for example, a device that provides various information to the driver of the host vehicle by voice and refers to a speaker or the like provided in the host vehicle.

  Further, the safety device 5 of the rear vehicle collision warning device according to the present embodiment includes a collision damage reducing device 54 and the like. The collision damage reducing device 54 reduces the collision conditions and protects the occupant of the own vehicle when there is a high risk of a collision with another vehicle or when a collision with another vehicle is unavoidable in accordance with an instruction from the control ECU 1. It is a device for performing.

  Specifically, the collision damage reduction device 54 increases the restraint of the occupant of the host vehicle by winding up the seat belt or driving the seat, thereby reducing the collision damage or safing the airbag. It can also be released or the seat position can be changed to a position in preparation for a collision.

  Next, an example of the flow of processing performed in the control ECU 1 of the rear vehicle collision warning device according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a diagram illustrating an example of a flow of processing performed in the control ECU 1 of the rear vehicle collision warning device according to the embodiment of the present invention.

  The flowchart shown in FIG. 2 is performed, for example, when the control ECU 1 executes a predetermined program stored in a storage unit (not shown) provided in the control ECU 1. 2 is started when the power source of the control ECU 1 is turned on (for example, the start / stop switch of the host vehicle on which the rear vehicle collision warning device is mounted is turned on).

  Further, the processing shown in the flowchart is ended when the power source of the control ECU 1 is turned off (for example, the start / stop switch of the host vehicle on which the rear vehicle collision warning device is mounted is turned off). In the following description, the start / stop switch is hereinafter abbreviated as SW.

  First, in step S11 of FIG. 2, the control ECU 1 determines whether or not the SW is ON. If it is determined that the SW is ON (YES), the process proceeds to the next step S12. On the other hand, when the control ECU 1 determines that the SW is not ON, that is, the SW is OFF (NO), the control ECU 1 ends the processing in the flowchart.

  In step S <b> 12, the control ECU 1 acquires vehicle information of the host vehicle from the vehicle information acquisition device 4. Note that the vehicle information acquired by the control ECU 1 from the vehicle information acquisition device 4 in step S12 is, for example, information indicating that a switch for performing the safety measure is pressed by the driver. . And control ECU1 advances a process to the following step S13.

  In step S13, the control ECU 1 determines whether or not to perform the safety measure. If the determination in step S13 is affirmative (YES), the control ECU 1 proceeds to the next step S14. If the determination is negative (NO), the control ECU 1 returns the process to step S12. Note that the case where the determination in step S13 is affirmative means that, specifically, the control ECU 1 turns on a switch for performing a safety measure based on the vehicle information acquired in step S12. This is the case.

  Next, in step S14, the control ECU 1 determines whether a vehicle has been detected behind the host vehicle, that is, whether another vehicle has been detected, based on information obtained from the camera 2 and the radar device 3.

  Note that, for example, the case where the control ECU 1 detects another vehicle from the rear image of the host vehicle obtained from the camera 2 in step S14 will be described below.

  As an example, the control ECU 1 performs a Sobel filter process in a predetermined direction of an image obtained from the camera 2 and extracts an edge point from the Sobel image using a luminance difference in the Sobel image after the process. I do. Then, the control ECU 1 uses the edge point extracted from the Sobel image and uses the difference in luminance in the Sobel image to emphasize an edge image (monochrome white with each point in the image as a luminance value). Edge image). Thereafter, the control ECU 1 performs pattern matching processing on the image from which the edge line is extracted using template images of image patterns of various vehicle types stored in a storage unit (not shown), and whether or not another vehicle exists. That is, it is determined whether or not another vehicle is detected.

  At this time, the control ECU 1 performs pattern matching processing on the image from which the edge line is extracted using template images of image patterns of various vehicle types stored in a storage unit (not shown) and detects other vehicles. At the same time, the detected vehicle type of the other vehicle (such as a large truck, an ordinary car, or a light car) may be specified.

  On the other hand, for example, in step S14, the control ECU 1 acquires a signal obtained from the radar device 3, and determines whether a vehicle behind the host vehicle is detected, that is, whether another vehicle is detected. May be. When the radar device 3 does not detect another vehicle (specifically, when there is no vehicle behind the host vehicle), the radar device 3 has a target of 0 (no other vehicle exists). Is output to the control ECU 1.

  And control ECU1 advances a process to step S15, when the judgment of the said step S14 is affirmed (YES), ie, when another vehicle is detected. On the other hand, if the determination in step S14 is negative (NO), that is, if there is no other vehicle, the process returns to step S14.

  In step S15, the control ECU 1 calculates information related to the other vehicle detected in step S14. Specifically, in step S15, the control ECU 1 calculates the relative speed and relative distance of the other vehicle with respect to the host vehicle.

  Here, for example, the case where the control ECU 1 calculates the relative speed and the relative distance of the other vehicle with respect to the host vehicle based on the image captured by the camera 2 will be described with reference to FIG.

  FIG. 3 is an image behind the host vehicle captured by the camera 2. In addition, it demonstrates supposing that the other vehicle is detected in the said image.

  As shown in FIG. 3, the control ECU 1 specifies the lower end of the other vehicle in the image shown in FIG. 3. In the image shown in FIG. 3, when the coordinate system having the origin at the upper left of the image is shown, the relationship between the value in the y direction in the coordinate system and the distance between the host vehicle and the other vehicle corresponding to the value is shown. Formulas, tables, and the like are stored in the control ECU 1 in advance.

  In this way, as shown in FIG. 3, for example, when the value of y at the lower end of the other vehicle is y1 in the image (coordinate system) shown in FIG. The distance between the vehicle and the other vehicle is calculated to be 10 m, for example.

  Further, the control ECU 1 images the other vehicle at a predetermined time interval, and calculates a relative speed of the other vehicle with respect to the own vehicle from a change in the distance between the own vehicle and the other vehicle.

  When taking into account the pitching of the host vehicle (swaying around the left and right axis of the vehicle body, sometimes referred to as pitching), the y coordinate of the vanishing point (FOE: Focus of Expansion) shown in FIG. 3 is used as a reference. It is preferable to store in advance in the control ECU 1 mathematical formulas, tables, and the like that indicate the relationship between the distance between the subject vehicle and the other vehicle. In this way, even if pitching occurs in the upward direction, the distance between the host vehicle and the other vehicle can be accurately calculated.

  On the other hand, for example, the control ECU 1 may calculate information on the relative distance and relative speed of the other vehicle with respect to the radar device 3 (with respect to the host vehicle) using the signal acquired from the radar device 3. Specifically, the control ECU 1 uses the sum and difference between the electromagnetic wave irradiated by the radar device 3 and the received reflected wave, transmission / reception timing, and the like, relative to the radar device 3 (relative to the host vehicle), the relative distance of other vehicles, Relative speed information is calculated.

  Returning to the description of step S15 in FIG. 2, the control ECU 1 temporarily stores information indicating the relative distance and relative speed calculated in step S15 in a storage unit (not shown), and proceeds to the next step S16.

  In step S16, the control ECU 1 determines the vehicle type of the other vehicle detected in step S14. More specifically, in step S16, the control ECU 1 calculates the lateral width W of the other vehicle detected from the rear image of the host vehicle obtained from the camera 2 in step S14.

  Here, the lateral width of the vehicle behind the host vehicle, that is, the other vehicle will be described with reference to FIG. FIG. 4 is a diagram showing the difference in the vehicle width depending on the vehicle type.

  4A shows an ordinary vehicle, FIG. 4B shows a large vehicle, and FIG. 4C shows a small vehicle. As an example, in this description, a normal vehicle is assumed to be a normal passenger car, a large vehicle is assumed to be a large vehicle such as a truck or a medium-sized vehicle, and a small vehicle is assumed to be a light vehicle. FIG. 4 shows the width of each vehicle type. In general, if the lateral width is large, the weight of the vehicle increases. In this description, on the basis of the lateral width Wa of the ordinary vehicle, the vehicle weight is greater if the lateral width is larger than the lateral width Wa of the ordinary vehicle. If the width is smaller than the width Wa of a normal vehicle, the vehicle weight is assumed to be small. As an example, the width of a large vehicle is Wb, and the width of a small vehicle is Wc.

  Returning to the description of FIG. 2, in step S16, the control ECU 1 determines the vehicle type of the other vehicle detected in step S14.

  Here, assuming a more specific scene, if the control ECU 1 calculates the lateral width W of the other vehicle from the image obtained from the camera 2, for example, if the lateral width W> the lateral width Wa, the control ECU 1 In S16, it is expected that the vehicle type is determined to be a large vehicle (because the vehicle width is larger than the width Wa of a normal vehicle). On the other hand, if the control ECU 1 calculates the lateral width W of the other vehicle from the image obtained from the camera 2, for example, if the lateral width W <the lateral width Wa, the control ECU 1 determines that the vehicle type is It is expected that the vehicle is a small vehicle (because the vehicle width is smaller than the width Wa). And control ECU1 memorize | stores the vehicle model of the other vehicle discriminate | determined in the said step S16 once in the memory | storage part which is not shown in figure, and advances a process to the following step S17.

  In step S <b> 16, the control ECU 1 calculates the lateral width W of the other vehicle from the image obtained from the camera 2. However, as described above, in step S14, the control ECU 1 uses the template images of the image patterns of various vehicle types stored in the storage unit (not shown) to extract an edge line (the edge image). Assume that the vehicle type (large truck, ordinary vehicle, light vehicle, etc.) is specified at the same time when the pattern matching process is performed.

  In this case, the control ECU 1 may temporarily store the vehicle type specified in step S14 in a storage unit (not shown) without calculating the lateral width W, and proceed to the next step S17. In other words, the control ECU 1 may determine the vehicle type from the size and shape of the other vehicle (including the lateral width) in the image in which the other vehicle is captured.

  In the above description, the control ECU 1 calculates the lateral width of the other vehicle from the image obtained from the camera 2, but the radar device 3 may be used. In general, it is known that a laser radar device is excellent in resolution in the left-right direction because a beam can be narrowed down. In particular, the laser radar device is used as the laser radar device. Based on the information obtained from the above, the lateral width of the other vehicle may be calculated using a known technique.

  Regarding the calculation of the lateral width of the other vehicle performed by the control ECU 1, the lateral width may be calculated by combining information obtained from the camera 2 and the radar device 3, or obtained from one of the camera 2 or the radar device 3. The width may be calculated using information.

  In step S17, the control ECU 1 selects a risk level table based on the vehicle type determined in step S16. In addition, the risk degree table for every vehicle type (normal vehicle, large vehicle, small vehicle) was shown in FIGS. In each table of FIGS. 5 to 7, K1 is the safest, K5 is the most dangerous, and the risk is shown as an example in five levels, K1 to K5. Specifically, the control ECU 1 determines each risk level table for large vehicles, ordinary vehicles, and small vehicles based on the information indicating the relative distance and relative speed calculated in step S15 and the vehicle type determined in step S17. (FIG. 5, FIG. 6, FIG. 7), the risk level table corresponding to the vehicle type is selected.

  In subsequent step S18, the control ECU 1 determines the risk level (K1 to K5) in the selected risk level table, proceeds to the next step S19, and in step S19, the determination is made in step S18. Determine whether safety measures are necessary based on the risk level.

  In step S19, the control ECU 1 determines whether a safety measure is necessary based on the degree of risk determined in step S18. In the following description, a safety measure is necessary in step S19. Suppose that it is determined (YES) that the safety measures will be executed in the next step S110.

  Although details will be described later, the mode of the safety measure that the control ECU 1 performs by controlling the safety device 5 differs depending on the degree of risk (K1 to K5). However, for the sake of simplicity, the outside display device 51 will be described below as an example. Then, the control ECU 1 selects a risk level table corresponding to the vehicle type, and in the selected table, the control ECU 1 determines the risk level based on the relative distance and the relative speed temporarily stored in the storage unit (not shown) in step S15. As a result of the determination, as the degree of danger increases with reference to the degree of danger K3 (K4, K5), the timing for turning on (flashing) the outside display device 51 is advanced, and as the degree of danger decreases (K2, K1). A description will be given assuming that the timing of turning on (flashing) the vehicle outside display device 51 is delayed.

  Hereinafter, the processing performed by the control ECU 1 in steps S15 to S19 will be described below assuming a specific scene.

  For example, the control ECU 1 detects another vehicle (the process in step S14), calculates the relative speed and relative distance of the other vehicle with respect to the host vehicle (the process in step S15), and the other vehicle is a normal vehicle. Is compared with the case where the control ECU 1 performs the same processing and determines that the other vehicle is a large vehicle. That is, a comparison is made between the case where the vehicle is an ordinary vehicle behind the host vehicle and the case where the vehicle is a large vehicle.

  Here, it is assumed that the relative speed and relative distance of the ordinary vehicle with respect to the own vehicle and the relative speed and relative distance of the large vehicle with respect to the own vehicle are the same. Specifically, for example, the relative speed of the ordinary vehicle with respect to the own vehicle is 15 km / h and the relative distance is 70 m. Similarly, the relative speed and relative distance of the large vehicle with respect to the own vehicle are also 15 km / h and 70 m, respectively. Suppose that there is.

  In general, the rotor and the frictional force (determined by the force applied to the brake) are F, the vehicle weight is m, the vehicle speed is v, the deceleration acceleration (sometimes referred to as deceleration G) is a, and time Where t is the energy taken by the rotor on the left side and energy taken from the vehicle on the right side is the following equation (1).

  When the equation (1) is solved for F, the following equation (2) is obtained.

  From the above equation (2), assuming that the force applied to the brake is constant, the deceleration acceleration a decreases as the vehicle weight m increases.

  That is, even if the relative speed and relative distance of the other vehicle with respect to the host vehicle are the same, if the vehicle type is different, more specifically, if the vehicle weight of the other vehicle is different, the driver of the other vehicle applies the brake. The time from stop to stop (time required for deceleration) varies depending on the vehicle weight. In other words, the greater the vehicle weight, the longer it takes to decelerate after the driver steps on the brake.

  In other words, the collision avoidance performance varies depending on the size and shape of the other vehicle. In other words, ordinary vehicles and trucks are different in size and shape, and large vehicles are inferior in collision avoidance performance (for example, the time from stepping on the brake to stopping) as estimated from the size and shape. .

  Returning to the description of FIG. 5 to FIG. 7, first, when the relative speed and the relative distance (15 km / h, 70 m) are applied in the (a) risk level table (ordinary vehicle) shown in FIG. It is determined that it is K2. On the other hand, when the relative speed and the relative distance (15 km / h, 70 m) are applied in the (b) risk level table (large vehicle) shown in FIG. 6, the risk level is determined to be K3.

  As a result, according to the rear vehicle collision warning device according to the present embodiment, when the vehicle behind the host vehicle is a large vehicle, the vehicle outside display is compared to the case where the vehicle behind the host vehicle is a normal vehicle. The timing for turning on (flashing) the device 51 is advanced.

  In other words, according to the rear vehicle collision warning device according to the present embodiment, for example, a driver of a large vehicle that takes time from depressing the brake to decelerating is notified early of the danger of a collision with the own vehicle. And the danger of collision can be notified at an appropriate timing. As a result, when a driver of a large vehicle notified by the vehicle outside display device 51 performs a brake operation, the timing for turning on (flashing) the vehicle outside display device 51 is earlier than in the case of a normal vehicle. It is expected that the brake will be operated with a margin.

  Next, for example, a case where the control ECU 1 determines that the other vehicle is a normal vehicle and a case where the other vehicle is determined to be a small vehicle are compared.

  It is assumed that the relative speed and relative distance of the ordinary vehicle with respect to the own vehicle and the relative speed and relative distance of the small vehicle with respect to the own vehicle are the same. Specifically, for example, the relative speed of the ordinary vehicle with respect to the own vehicle is 15 km / h and the relative distance is 70 m. Similarly, the relative speed and relative distance of the small vehicle with respect to the own vehicle are also 15 km / h and 70 m, respectively. Suppose that.

  First, when the relative speed and the relative distance (15 km / h, 70 m) are applied in the (a) risk level table (ordinary vehicle) shown in FIG. 5, the risk level is determined to be K2. On the other hand, when the relative speed and the relative distance (15 km / h, 70 m) are applied in the (c) risk level table (small car) shown in FIG. 5, the risk level is determined to be K2.

  In other words, when the relative speed and the relative distance of the ordinary car and the small car are 15 km / h and 70 m, respectively, the risk is the same. However, for example, even if the relative speeds of the normal vehicle and the small vehicle are the same (each 15 km / h), if the vehicle is closer to the host vehicle, the small vehicle is compared to the normal vehicle. However, the timing of turning on (flashing) the vehicle exterior display device 51 is delayed (for example, the risk levels enclosed in a thick frame in the risk level tables shown in FIGS. 5 and 7 are compared).

  As described above, when the vehicle behind the host vehicle is a small vehicle, the time from stepping on the brake to decelerating is shorter than when the vehicle behind the host vehicle is a normal vehicle. Faster than In other words, in the case of small cars compared to ordinary cars and large cars, it takes less time to step on the brakes and then decelerate. The driver of a small car that travels has a sense of incongruity, which is a so-called early warning.

  However, according to the rear vehicle collision warning device according to the present embodiment, when the vehicle behind the host vehicle is a small vehicle, the timing for turning on (flashing) the outside display device 51 is compared with the case of a normal vehicle or a large vehicle. Because it can be delayed, there is no early warning.

  In addition, although how to apply the risk levels (K1 to K5) in each risk level table of FIGS. 5 to 7 is an example, as described above, for example, in the case of a large vehicle, until the vehicle decelerates after stepping on the brake. It takes time, and if a large car collides from behind, the damage is greater than that of an ordinary car or a small car. For this reason, as indicated by the shading of each risk level table in FIGS. 5 to 7, more risk K5 points are set than in the case of ordinary cars and small cars.

  That is, when setting the risk level in the risk level table, it may be determined in consideration of the time from when the brake is depressed until the vehicle decelerates, the magnitude of damage in the event of a collision.

  In the above description, it is assumed that a safety measure is necessary in step S19, and the timing for turning on (flashing) the vehicle exterior display device 51 is made earlier or later depending on the degree of danger. However, the present invention is not limited to this. That is, in various devices included in the safety device 5 including the display device 51 outside the vehicle, the safety measures performed by the safety device 5 may be changed according to the degree of risk.

  For example, as an example, the control ECU 1 turns on (flashes) the vehicle outside display device 51 when the danger level is K3 or higher, and displays the vehicle outside display as the risk levels K4 and K5 are based on the risk level K3. The timing for turning on (flashing) the device 51 may be advanced.

  The control ECU 1 controls the in-vehicle display device 52 and the alarm device 53 in addition to lighting (flashing) the in-vehicle display device 51 when the degree of risk is K3 or higher. Not only the driver but also the driver of the host vehicle may be informed of the vehicle type behind the host vehicle, and a warning or display that indicates the degree of danger.

  On the other hand, the control ECU 1 controls the in-vehicle display device 52 and the alarm device 53 without lighting (flashing) the outside display device 51 when the degree of risk is less than K3, and controls the own vehicle driver. The rear vehicle type may be notified, or a warning or display indicating the degree of danger may be given.

  Furthermore, in the case of the highest risk level K5, the timing of turning on (flashing) the outside display device 51 is advanced to notify other vehicles, or the vehicle type behind the host vehicle is specified to the driver of the host vehicle. In addition to notifying and displaying warnings and indications indicating the degree of danger, the control ECU 1 controls the collision damage reducing device 54 to wind up the seat belt, drive the seat, It may be possible to increase the restraint of the seat or change the seat position to a position prepared for a collision.

  In the above-described example, the control ECU 1 temporarily assumes that a safety measure is necessary in step S19 (YES), and executes the safety measure in the next step S110. However, for example, in the case of the risk levels K2 and K1, the control ECU 1 may determine that the risk level is low and deny (NO) the determination in step S110 so as not to perform the safety measure.

  Returning to FIG. 2, in step S111, the control ECU 1 determines whether or not the SW of the host vehicle is turned off. If the control ECU 1 determines that the SW is OFF (YES), the process in the flowchart ends. On the other hand, if the control ECU 1 determines that the SW of the host vehicle is not turned off (NO), the process returns to step S12.

  As mentioned above, according to the back vehicle collision warning device concerning one embodiment of the present invention, the back vehicle collision warning device which can notify the danger of a collision to the driver of other vehicles at an appropriate timing can be provided.

  In the above description of the embodiment, for example, the vehicle outside display 51 is used as means for notifying the driver of the vehicle behind the host vehicle. For example, the vehicle and the vehicle behind the host vehicle may be referred to as a so-called vehicle. When a device capable of performing inter-vehicle communication is provided, the driver of the vehicle behind the host vehicle is too close to the host vehicle via the vehicle-to-vehicle communication, and the possibility of collision is high. Information may be provided.

  As mentioned above, although one Embodiment of this invention was described in detail, the aspect demonstrated by the said embodiment shows a specific example, and does not limit the technical scope of this invention at all. Therefore, any configuration can be adopted within a range where the effect of the present application is achieved.

  The rear vehicle collision warning device according to the present invention is capable of notifying the driver of the other vehicle of the risk of collision at an appropriate timing by determining the vehicle type of the other vehicle behind the host vehicle. It is useful as a vehicle collision warning device.

1 ... Control ECU
DESCRIPTION OF SYMBOLS 2 ... Camera 3 ... Radar apparatus 4 ... Vehicle information acquisition apparatus 5 ... Safety apparatus 51 ... Outside display apparatus 52 ... In-vehicle display apparatus 53 ... Alarm apparatus 54 ... Collision damage reduction apparatus

Claims (6)

A rear vehicle collision warning device that is mounted on the host vehicle and notifies the approach of the vehicle,
Detecting means for detecting another vehicle behind the host vehicle and outputting information indicating that the other vehicle has been detected;
Informing means for informing at least the other vehicle that the other vehicle is approaching the host vehicle;
Control means for controlling the notification means and controlling the mode of notification performed by the notification means,
The control means determines the degree of approach between the host vehicle and the other vehicle based on information indicating that the other vehicle output from the detection means is detected, and estimates the collision avoidance performance of the other vehicle, A rear vehicle collision warning device, wherein control according to the degree of approach and the collision avoidance performance is performed on the notification means.   2. The rear vehicle collision according to claim 1, wherein the control unit performs the notification by controlling the notification unit when the degree of approach exceeds a reference determined according to the collision avoidance performance. Alarm device.   The collision avoidance performance of the other vehicle estimated by the control means is estimated from the size or shape of the other vehicle calculated based on information indicating that the other vehicle output from the detection means is detected. The rear vehicle collision warning device according to claim 1, wherein the rear vehicle collision warning device is provided.   The control means calculates a relative speed and a relative distance of the other vehicle with respect to the own vehicle based on information indicating that the other vehicle output from the detection means is detected, and based on the relative speed and the relative distance, The rear vehicle collision warning device according to claim 1 or 2, wherein an approach degree is determined.   3. The rear vehicle collision warning device according to claim 2, wherein when the control unit determines that the reference is exceeded, the control unit controls the notification unit and further notifies a passenger of the host vehicle. 4. . The detection means is at least one of a radar device and a camera,
2. The rear vehicle collision warning device according to claim 1, wherein the notification means is at least one of a direction indicator and a tail lamp mounted on the host vehicle.

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