JP2018144600A - Rear warning device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce unnecessary warning operations.SOLUTION: In the case where the following vehicle is detected (S22: Yes), a rear warning ECU 10 determines that the following vehicle is in a passing operation of the own vehicle when following three conditions are satisfied: acceleration G1 in a longitudinal direction of the following vehicle is equal to or greater than a passing determination threshold G1ref (S24: Yes); acceleration G2 in a transverse direction of the following vehicle is equal to or greater than a passing determination threshold G2ref (S25: Yes); and an offset D being a distance where the following vehicle is deviated in a vehicle width direction of the own vehicle, is equal to or greater than a passing determination threshold Dref (S26: Yes). In the case where a determination is made that the following vehicle is in the passing operation of the own vehicle, the rear warning ECU 10 does not issue warning even when the following vehicle approaches the own vehicle.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a vehicle rear warning device that issues a warning to a subsequent vehicle that may collide with the host vehicle from behind.

  2. Description of the Related Art Conventionally, a vehicular rear warning device that issues a warning to a subsequent vehicle that may collide with the host vehicle from behind is known. The vehicle rear warning device detects, for example, a succeeding vehicle approaching from behind the host vehicle, calculates a predicted collision time that is required for the succeeding vehicle to collide with the host vehicle, and the predicted collision time is a threshold value. When the following occurs, a hazard lamp blinks to alert the following vehicle.

  Further, the vehicle rear warning device proposed in Patent Document 1 estimates the degree of difficulty with which the subsequent vehicle avoids a collision with the host vehicle by a steering operation, and based on the estimated degree of avoidance, It is configured to vary the timing of the alarm to be performed.

JP 2014-854 A

  The vehicle rear warning device proposed in Patent Document 1 determines the degree of difficulty of avoidance based on the lateral movement distance required for the following vehicle to avoid a collision. Specifically, when the lateral movement distance required to avoid a collision is greater than or equal to a predetermined distance (a value that is smaller than the vehicle width of the host vehicle and greater than half the vehicle width of the host vehicle), avoidance is performed. It is determined that the degree of difficulty is high. In this case, the vehicular rear warning device advances the warning timing for the following vehicle.

  However, the above-described device merely determines the degree of difficulty of avoidance based on the lateral position of the subsequent vehicle relative to the host vehicle, and does not determine whether the subsequent vehicle is performing a collision avoidance operation. For this reason, an alarm may be issued even though the collision avoidance operation is actually performed. That is, an unnecessary alarm may be issued.

  The present invention has been made to solve the above-described problems, and an object thereof is to reduce unnecessary alarm operations.

In order to achieve the above object, the feature of the vehicle rear warning device of the present invention is:
In a vehicle rear warning device that warns a subsequent vehicle that may collide with the host vehicle from behind,
Motion state acquisition means (10, S24, S25, S26) for acquiring information representing the motion state of the following vehicle;
An overtaking operation determining means (10, S24 to S26) for determining whether or not the following vehicle is in an overtaking operation for overtaking the host vehicle based on the motion state of the following vehicle;
Alarm limiting means (10, S27, S15: No, S19) for limiting an alarm to be given to the subsequent vehicle when the overtaking operation determining means determines that the subsequent vehicle is in an overtaking operation; Be prepared.

  The vehicle rear warning device of the present invention issues a warning to a subsequent vehicle that may collide with the host vehicle from behind. For example, the vehicular rear warning device issues a warning to the subsequent vehicle when the predicted collision time, which is the predicted time required for the subsequent vehicle to collide with the host vehicle, is equal to or less than a threshold value.

  When the driver of the following vehicle is overtaking to avoid a collision, it is not necessary to issue a warning. Therefore, the present invention includes an exercise state acquisition unit, an overtaking operation determination unit, and an alarm limitation unit. The motion state acquisition means acquires information representing the motion state (behavior) of the following vehicle. The overtaking operation determination means determines whether or not the subsequent vehicle is in an overtaking operation for overtaking the host vehicle based on the motion state of the subsequent vehicle.

  For example, the motion state acquisition means may use the following vehicle as the motion state of the following vehicle: forward acceleration of the following vehicle in the own vehicle, lateral acceleration of the following vehicle in the own vehicle, and amount of displacement of the subsequent vehicle in the lateral direction relative to the own vehicle. Get information representing. The overtaking motion determination means is such that the forward acceleration of the following vehicle in the host vehicle is greater than or equal to a threshold value (forward acceleration threshold value), and the lateral acceleration of the subsequent vehicle in the host vehicle is greater than or equal to the threshold value (lateral acceleration threshold value). When the amount of displacement of the lateral position of the subsequent vehicle relative to the own vehicle is equal to or greater than a threshold value (lateral distance threshold value), it may be determined that the subsequent vehicle is in an overtaking operation.

  The warning limiting unit limits a warning to be given to the following vehicle when the overtaking operation determining unit determines that the following vehicle is in the overtaking operation. For example, the warning limiting unit prohibits warning for the following vehicle. Alternatively, the warning limiting unit changes the warning execution condition for warning the following vehicle so that the warning is difficult to be given. For example, in a configuration in which an alarm is performed based on the predicted collision time, the threshold value for the predicted collision time is changed to a short value.

  As a result, according to the present invention, since the warning is limited for the following vehicle that is performing the overtaking operation, it is possible to reduce unnecessary warning operations.

  In the above description, in order to assist the understanding of the invention, the reference numerals used in the embodiments are attached to the constituent elements of the invention corresponding to the embodiments in parentheses. It is not limited to the embodiment defined by.

1 is a schematic system configuration diagram of a vehicle rear warning device according to an embodiment. It is a top view showing the detection angle of a rear side radar. It is a flowchart showing a rear warning control routine. It is a top view explaining the appropriate action | operation of a warning, and malfunction. It is a top view explaining the feature of overtaking operation of a succeeding vehicle. It is a flowchart showing a flag setting routine. It is a flowchart showing the back warning control routine as a modification.

  Hereinafter, a vehicle rear warning device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic system configuration of a vehicle rear warning device according to an embodiment of the present invention. The vehicle rear warning device is mounted on a vehicle (hereinafter, sometimes referred to as “own vehicle” in order to be distinguished from other vehicles). The vehicle rear alarm device includes a rear alarm ECU 10 and a meter ECU 20.

  Each of the ECUs 10 and 20 is an electric control unit (Electric Control Unit) having a microcomputer as a main part, and is connected to be able to transmit and receive information to and from each other via a CAN (Controller Area Network) 50. In this specification, the microcomputer includes a CPU, a ROM, a RAM, a nonvolatile memory, an interface I / F, and the like. The CPU implements various functions by executing instructions (programs, routines) stored in the ROM.

  The CAN 50 is connected to a plurality of types of vehicle state sensors 30 that detect the state of the host vehicle and a plurality of types of driving operation state sensors 40 that detect the driving operation state of the driver. The vehicle state sensor 30 includes, for example, a vehicle speed sensor that detects a traveling speed of the host vehicle, a wheel speed sensor that detects a wheel speed, a front-rear G sensor that detects a longitudinal acceleration of the host vehicle, and a lateral acceleration of the host vehicle. A lateral G sensor to detect, a yaw rate sensor to detect the yaw rate of the host vehicle, and the like.

  The driving operation state sensor 40 detects an accelerator operation amount sensor that detects an operation amount of an accelerator pedal, a brake operation amount sensor that detects an operation amount of a brake pedal, a brake switch that detects whether or not the brake pedal is operated, and a steering angle. A steering angle sensor, a steering torque sensor that detects steering torque, and the like.

  The CAN 50 is connected to ECUs for performing various vehicle controls such as an engine ECU, a brake ECU, and a steering ECU (not shown), but these are not directly related to the vehicle rear alarm device in the present embodiment. Is omitted.

  Information (referred to as sensor information) detected by the vehicle state sensor 30 and the driving operation state sensor 40 is transmitted to the CAN 50. In each ECU, the sensor information transmitted to the CAN 50 can be used as appropriate. The sensor information is information on a sensor connected to a specific ECU, and may be transmitted from the specific ECU to the CAN 50.

  The rear warning ECU 10 is a control device that is the core of the rear warning control system. As shown in FIG. 2, the rear warning ECU 10 is connected to a left rear side radar 11L and a right rear side radar 11R provided at the left and right corners of the rear bumper. The left rear side radar 11L and the right rear side radar 11R have the same configuration except for the detection area. Hereinafter, when it is not necessary to distinguish the left rear side radar 11L and the right rear side radar 11R, both are referred to as the rear side radar 11.

  The rear side radar 11 includes a radar transmission / reception unit and a signal processing unit (not shown), and the radar transmission / reception unit radiates a millimeter-wave band radio wave (hereinafter referred to as “millimeter wave”). , A millimeter wave (that is, a reflected wave) reflected by a three-dimensional object (for example, another vehicle, a pedestrian, a bicycle, or a building) existing within the radiation range is received. The signal processing unit detects a three-dimensional object based on the phase difference between the transmitted millimeter wave and the received reflected wave, the attenuation level of the reflected wave, and the time from when the millimeter wave is transmitted until the reflected wave is received. .

  As shown in FIG. 2, the right rear side radar 11 </ b> R uses a range of a predetermined right and left angle with respect to the central axis directed obliquely rearward to the right from the right rear corner of the vehicle body as a three-dimensional object detection region. The left rear side radar 11L has a three-dimensional object detection area in a range of a predetermined left and right angle with respect to the central axis directed diagonally left rearward from the vehicle body left rear corner. The detection area of the right rear side radar 11R and the detection area of the left rear side radar 11L overlap on the vehicle rear side. Accordingly, the three-dimensional object behind the vehicle can be detected by the left and right rear side radars 11. FIG. 2 shows the detection angle range of the rear side radar 11, and the detection distance of the rear side radar 11 is several tens of meters, for example.

  The rear side radar 11 is information related to the detected three-dimensional object, for example, information indicating the distance between the host vehicle and the three-dimensional object, the relative speed between the host vehicle and the three-dimensional object, the relative position of the three-dimensional object with respect to the host vehicle (hereinafter referred to as the three-dimensional object). , Referred to as rear peripheral information) is supplied to the rear warning ECU 10 at a predetermined short cycle.

  The rear warning ECU 10 is intended to prevent the following vehicle traveling behind the own vehicle from colliding with the own vehicle. Therefore, the three-dimensional object detected by the rear side radar 11 is hereinafter referred to as the following vehicle or Called another vehicle.

  For example, the rear warning ECU 10 detects the target vehicle based on the rear periphery information supplied from the rear side radar 11 with the subsequent vehicle approaching the host vehicle from the rear on the traveling locus of the host vehicle as the target vehicle, and When it is determined that the target vehicle may collide with the host vehicle, a rear warning command is transmitted to the meter ECU 20 via the CAN 50.

  The rear alarm ECU 10 of the present embodiment is unitized as a unit with the left rear side radar 11L or the right rear side radar 11R, and is provided at one of the left and right rear corners of the vehicle body. Note that the rear warning ECU 10 does not necessarily need to be unitized with the rear side radar 11, and can be arranged at an arbitrary position separately from the rear side radar 11.

  The meter ECU 20 is connected to the left and right hazard lamps 21 and the display 22. The meter ECU 20 includes a lamp drive circuit (not shown), and when the rear alarm command is received via the CAN 50, the left and right hazard lamps 21 blink simultaneously. Moreover, meter ECU20 displays the display screen showing the back alarm having been performed on the indicator 22, when back alarm instruction | command is received.

  Next, rear warning control performed by the rear warning ECU 10 will be described. FIG. 3 shows a rear warning control routine executed by the rear warning ECU 10. The rear warning control routine is repeatedly executed at a predetermined short calculation cycle while the ignition switch is on.

  When the rear warning control routine is activated, the rear warning ECU 10 acquires the rear peripheral information transmitted from the left and right rear side radars 11 in step S11, and in step S12, based on the rear peripheral information, It is determined whether or not the following vehicle is detected. The rear warning ECU 10 once ends this routine when the following vehicle is not detected, and proceeds to step S13 when the following vehicle is detected.

  In step S13, the rear warning ECU 10 is the estimated time required for the subsequent vehicle to collide with the own vehicle from the present time based on the relative speed Vr of the subsequent vehicle with respect to the own vehicle and the distance Dr between the own vehicle and the subsequent vehicle. A certain collision prediction time (TTC: Time To Collision) is calculated. For example, the collision prediction time TTC is calculated by (Dr / Vr). The predicted collision time TTC may be calculated in consideration of, for example, the acceleration / deceleration at which the target vehicle approaches the host vehicle. The predicted collision time TTC is an index of the possibility that the following vehicle will collide with the own vehicle, and it can be estimated that the smaller the value, the higher the possibility that the following vehicle will collide with the own vehicle.

  Subsequently, in step S14, the rear warning ECU 10 determines whether or not the predicted collision time TTC is equal to or shorter than the rear warning threshold value TTCref. When the predicted collision time TTC exceeds the rear warning threshold value TTCref (S14: No), the rear warning ECU 10 once ends this routine.

  The rear warning ECU 10 reads the overtaking flag F in step S15 when the predicted collision time TTC becomes equal to or shorter than the rear warning threshold value TTCref while repeating such processing (S14: Yes), and the overtaking flag F is “0”. Is determined. The overtaking flag F is set to “0” or “1” by a flag setting routine described later. The overtaking flag F is set to “1” when it is estimated that the following vehicle is performing the overtaking operation, and is set to “0” otherwise.

  When the overtaking flag F is “0”, the rear warning ECU 10 transmits a rear warning command to the meter ECU 20 in step S16. Thereby, meter ECU20 blinks hazard lamp 21, and issues a warning to the following vehicle.

  On the other hand, when the overtaking flag F is “1”, the rear warning ECU 10 skips the process of step S16 and temporarily ends this routine. Therefore, no warning is given to the following vehicle.

  In this rear warning control routine, even if the predicted collision time TTC is equal to or shorter than the rear warning threshold value TTCref, if it is determined that the succeeding vehicle is performing the overtaking operation, the warning for the following vehicle is prohibited. The The reason will be described.

  For example, as shown in FIG. 4A, a state is considered in which the following vehicle C2 approaches the warning area A (region where the predicted collision time TTC is equal to or less than the rear warning threshold value TTCref) from the rear of the host vehicle C1. From this state, when the following vehicle C2 enters the warning area A, two scenes can be considered. As shown in FIG. 4B, one is a scene where the following vehicle C2 enters the warning area A as it is (referred to as scene 1), and the other is as shown in FIG. 4C. Furthermore, this is a scene (referred to as scene 2) in which the following vehicle C2 enters the warning area A while performing an overtaking operation for overtaking the host vehicle C1.

  In scene 1, there is a possibility that the following vehicle C2 may collide with the own vehicle C1, so that the warning system is activated and a warning should be issued to the following vehicle C2. Therefore, this alarm is a proper operation.

  On the other hand, in the scene 2, since it can be estimated that the driver is aware of the host vehicle ahead, it is considered that the following vehicle C2 does not collide with the host vehicle C1. Therefore, it can be said that it is an erroneous operation to recognize that the succeeding vehicle C2 collides with the own vehicle C1 and issue a warning just because the following vehicle C2 enters the warning area A.

  In the conventional vehicle rear warning device, such scene 1 and scene 2 cannot be separated, and a warning (unnecessary warning) is also given in scene 2.

  Therefore, in this embodiment, it is determined whether or not the succeeding vehicle is performing an overtaking operation based on the motion state (behavior) of the subsequent vehicle. The system is designed to stop the alarm operation.

For example, when the following vehicle starts an overtaking operation, the following characteristic motion states are detected as shown in FIG.
(1) Forward acceleration is generated in the following vehicle.
(2) Lateral acceleration is generated in the following vehicle.
(3) The position of the following vehicle is offset laterally with respect to the host vehicle.
(4) The traveling direction of the following vehicle is inclined with respect to the own vehicle.
(5) The lateral movement of the following vehicle continues.

(1) represents a behavior in which the following vehicle C2 overtakes the host vehicle C1. (2) to (5) represent behaviors in which the following vehicle C2 avoids the host vehicle C1. The rear warning ECU 10 pays attention to the movement state of the following vehicle and determines whether or not the following vehicle is overtaking as follows.

  FIG. 6 shows a flag setting routine executed by the rear warning ECU 10. The flag setting routine is repeatedly executed at a predetermined calculation period in parallel with the rear warning control routine while the rear warning control routine described above is being executed.

  When the flag setting routine is activated, the rear warning ECU 10 acquires the rear peripheral information transmitted from the left and right rear side radars 11 in step S21, and in step S22, based on the rear peripheral information, It is determined whether or not a subsequent vehicle is detected. If no following vehicle is detected, the rear warning ECU 10 sets the overtaking flag F to “0” in step S23.

When a subsequent vehicle is detected behind the host vehicle (S22: Yes), the rear warning ECU 10 calculates the acceleration G1 in the front-rear direction of the subsequent vehicle in step S24, and the acceleration G1 is a preset overtaking determination threshold. It is determined whether or not it is greater than or equal to G1ref. This acceleration G1 is the acceleration of the following vehicle ahead in the front-rear direction (front-rear axis direction) of the host vehicle. For example, the rear alarm ECU 10 subtracts the longitudinal acceleration (detected value of the longitudinal G sensor) of the own vehicle from the temporal change (relative acceleration) of the relative speed in the longitudinal direction of the succeeding vehicle with respect to the own vehicle. An acceleration G1 of the vehicle is calculated. The acceleration G1 is one element for determining that the following vehicle is performing an operation of overtaking the host vehicle. The overtaking determination threshold G1ref is, for example, 1 m / s ² .

  When the acceleration G1 is less than the overtaking determination threshold G1ref set in advance, the rear warning ECU 10 determines that the following vehicle is not performing the overtaking operation, and advances the process to step S23. On the other hand, when the acceleration G1 is equal to or more than the preset overtaking determination threshold G1ref, the rear alarm ECU 10 advances the process to step S25.

In step S25, the rear warning ECU 10 calculates the lateral acceleration G2 of the following vehicle, and determines whether or not the acceleration G2 is equal to or greater than a preset overtaking determination threshold G2ref. This acceleration G2 is the acceleration of the succeeding vehicle in the lateral direction (vehicle width direction) of the host vehicle. For example, the rear alarm ECU 10 subtracts the lateral acceleration (detected value of the lateral G sensor) of the own vehicle from the temporal change (relative acceleration) of the lateral relative speed of the succeeding vehicle with respect to the own vehicle. The acceleration G2 of the vehicle is calculated. The acceleration G2 is one element for determining that the following vehicle is performing an operation of overtaking the host vehicle. The overtaking determination threshold G2ref is, for example, 0.1 m / s ² . In this case, the acceleration G2 represents an absolute value that does not distinguish the left-right direction.

  When the acceleration G2 is less than the preset overtaking determination threshold G2ref, the rear alarm ECU 10 determines that the following vehicle is not performing the overtaking operation, and advances the process to step S23. On the other hand, when the acceleration G2 is equal to or more than the preset overtaking determination threshold G2ref, the rear warning ECU 10 advances the process to step S26.

  In step S26, the rear warning ECU 10 calculates a distance D (referred to as an offset D) in which the subsequent vehicle is displaced in the vehicle width direction of the own vehicle in the relationship between the traveling position of the own vehicle and the traveling position of the subsequent vehicle. It is determined whether or not the offset D is greater than or equal to a preset overtaking determination threshold Dref. This offset D is one element for determining that the following vehicle is performing an operation of overtaking the host vehicle. The overtaking determination threshold Dref is, for example, 0.5 m. This offset D is a distance (in the left-right direction that is not distinguished between the center position of the host vehicle) and the center position of the following vehicle detected by the rear side radar. (Absolute value).

  When the offset D is less than the preset overtaking determination threshold Dref, the rear warning ECU 10 determines that the following vehicle is not performing the overtaking operation, and advances the process to step S23. On the other hand, when the offset D is equal to or greater than the preset overtaking determination threshold Dref, the rear warning ECU 10 determines that the following vehicle is in the overtaking operation of overtaking the host vehicle, proceeds with the process to step S27, and is overtaking. The flag F is set to “1”.

  When the rear warning ECU 10 sets the overtaking flag F in step S23 or step S27, the flag setting routine is once ended. Then, the flag setting routine is repeated at a predetermined calculation cycle. Therefore, the overtaking flag F set in the flag setting routine is information representing in real time the determination result of whether or not the following vehicle is performing the overtaking operation.

  As described above, when the overtaking flag F is “1” in the rear warning control routine, even if the predicted collision time TTC with the following vehicle is equal to or less than the warning threshold value TTCref, the rear warning ECU 10 The warning for is not carried out. That is, the warning operation is not performed for the following vehicle that is estimated to be overtaking the host vehicle.

  According to the vehicle rear warning device of the present embodiment described above, the longitudinal acceleration G1 of the following vehicle is not less than the overtaking determination threshold G1ref (S24: Yes), and the lateral acceleration G2 of the following vehicle is overtaking determination threshold. G3ref or more (S25: Yes), and when the three conditions that the offset D, which is the distance that the following vehicle is displaced in the vehicle width direction of the own vehicle, are more than the overtaking determination threshold Dref (S26: Yes) are satisfied. It is determined that the following vehicle is in the overtaking operation of overtaking the host vehicle. When it is determined that the following vehicle is in the overtaking operation, the warning for the following vehicle is prohibited. As a result, unnecessary alarm operation can be reduced.

<Modification of rear warning control routine>
For example, in the present embodiment, when the overtaking flag F is set to “1”, the alarm operation is prohibited. However, it is not always necessary to prohibit the alarm operation, and the alarm is performed so that the alarm is difficult to be performed. The structure which changes conditions may be sufficient. For example, when the overtaking flag F is set to “1”, the rear warning threshold value TTCref is changed to a smaller value than when the overtaking flag F is set to “0”. Also good.

  In this case, for example, a rear warning control routine shown in FIG. 7 may be executed instead of the rear warning control routine of FIG. In the rear warning control routine of this modification, steps S17, S18, and S19 are incorporated between steps S13 and S14 in the rear warning control routine (FIG. 3) of the embodiment, and step S15 is deleted. . Hereinafter, although the rear warning control routine of a modification is demonstrated, about the same process as the rear warning control routine of embodiment, a common step code | symbol is attached | subjected to drawing and description is abbreviate | omitted.

  After calculating the predicted collision time TTC in step S13, the rear warning ECU 10 reads the overtaking flag F in step S17, and determines whether or not the overtaking flag F is “0”.

  When the overtaking flag F is “0”, the rear warning ECU 10 sets the value of the rear warning threshold value TTCref to the normal threshold value TTCref1 (TTCref ← TTCref1) in step S18. On the other hand, when the overtaking flag F is “1”, the rear warning ECU 10 sets the value of the rear warning threshold TTCref to the overtaking threshold TTCref2 in step S19 (TTCref ← TTCref2). This overtaking threshold value TTCref2 is set to a value smaller than the normal threshold value TTCref1 (TTCref2 <TTCref1).

  When the rear alarm ECU 10 sets the value of the rear alarm threshold value TTCref in step S18 or step S19, the process proceeds to step S14 to determine whether or not the predicted collision time TTC is equal to or less than the rear alarm threshold value TTCref. To do. The rear warning ECU 10 transmits a rear warning command to the meter ECU 20 in step S16 when the collision predicted time TTC is equal to or shorter than the rear warning threshold TTCref, and when the collision predicted time TTC is larger than the rear warning threshold TTCref, The process of step S16 is skipped.

  Therefore, when the succeeding vehicle is in the overtaking operation, the alarm threshold value TTCref is changed to a small value, so that the alarm is limited (it becomes difficult to perform the alarm), and unnecessary alarm operations can be reduced.

  The vehicular rear warning device according to the present embodiment has been described above, but the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  For example, in the present embodiment, a radar sensor is used as a sensor for detecting the periphery of the host vehicle, but other peripheral sensors such as a camera sensor and a laser sensor may be used instead. Further, the mounting position and the number of mounting of the peripheral sensors can be arbitrarily set.

  Further, the determination as to whether or not the following vehicle is performing an overtaking operation can be performed in combination with other motion state elements. For example, in step S24, instead of the forward acceleration of the following vehicle, the forward relative acceleration G1 ′ of the following vehicle with respect to the host vehicle is used for comparison with the overtaking determination threshold G1′ref (G1 ′ ≧ G1′ref). ). Further, for example, in step S25, instead of the lateral acceleration of the following vehicle, the lateral relative acceleration G2 ′ of the succeeding vehicle is compared with the overtaking determination threshold G2′ref (G2 ′ ≧ G2). 'ref) may be configured.

  DESCRIPTION OF SYMBOLS 10 ... Back warning ECU, 11 ... Rear side radar, 20 ... Meter ECU, 21 ... Hazard lamp, 30 ... Vehicle state sensor, 40 ... Driving operation state sensor, C1 ... Own vehicle, C2 ... Subsequent vehicle, F ... Overtaking flag.

Claims (1)

In a vehicle rear warning device that warns a subsequent vehicle that may collide with the host vehicle from behind,
Motion state acquisition means for acquiring information representing the motion state of the subsequent vehicle;
An overtaking operation determination means for determining whether or not the subsequent vehicle is in an overtaking operation for overtaking the own vehicle based on a motion state of the subsequent vehicle;
A vehicle rear alarm device, comprising: an alarm limiting unit that limits an alarm to be given to the subsequent vehicle when the overtaking operation determination unit determines that the subsequent vehicle is in an overtaking operation.

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