Driving assistance device

Abstract

To provide a driving support device capable of easily specifying which side of an object to be avoided a driver should pay attention to when the object to be avoided is present on the same side as a side where a rear object is present and on the opposite side, and increasing the possibility that the driver notices the object to be avoided.SOLUTION: When a warning condition including a condition that a rear object is present on the right side or the left side behind the vehicle is satisfied, the driving support device issues a rear warning about the rear object. When the warning condition is satisfied and a front condition including a condition that the avoidance target object is present on a side opposite to a side where the rear object is present is satisfied, the driving support device issues a warning using a sound for the avoidance target object present on the opposite side and issues a rear warning in a mode other than a sound, and even when the avoidance target object is present on the same side as the side where the rear object is present, the driving support device does not issue a warning using a sound for the avoidance target object present on the same side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device that issues a rear warning about a rear object when warning conditions including at least a condition that a rear object is present on at least one of the right and left sides behind the vehicle are met. [Background technology]

[0002] Conventionally, there have been known driving assistance devices that issue a rearward warning for a rearward object that exists on at least one of the right and left sides behind the vehicle. For example, the driving assistance device described in Patent Document 1 (hereinafter referred to as the "conventional device") issues a rearward warning using sound and video when a rearward object exists. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-071198 Summary of the Invention

[0004] A driving assistance device is being considered that issues a warning for an object to be avoided that is present in front of the vehicle while also issuing a rear warning. The object to be avoided is an object that is present in front of the vehicle and that causes the vehicle to change its direction of travel to avoid contact. This warning increases the likelihood that the driver will notice the object to be avoided, so this driving assistance device can reduce the likelihood of the vehicle coming into contact with the object to be avoided.

[0005] When there is a rear object and an object to be avoided, the driver is likely to look at the side mirror to see the rear object. Therefore, even if a visual warning is issued to the driver regarding the object to be avoided, the driver may not notice the warning. Therefore, it is desirable to issue a warning regarding the object to be avoided using sound.

[0006] In some cases, there are objects to be avoided on both the same side as the rear object and on the opposite side. In this case, if an audible warning is issued for the objects to be avoided on both sides, the driver is likely to be unable to determine which side they should pay attention to.

[0007] The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a driving assistance device that makes it easier for the driver to identify which object to avoid that the driver should pay attention to when there are objects to avoid on both the same side and the opposite side of the side where a rear object is present, and that increases the likelihood that the driver will notice the object to avoid.

[0008] The driving assistance device of the present invention (hereinafter referred to as the "device of the present invention") issues a rear warning for a rear object (step 340) when an alarm condition is met that includes at least the condition that a rear object (RO) is present on either the right or left side behind the vehicle (VA) (step 310 "Yes"). The driving assistance device When the warning condition is satisfied (step 310 "Yes"), and further when a forward condition is satisfied that includes at least a condition that an object to be avoided that exists in front of the vehicle and that causes the vehicle to change its traveling direction to avoid contact exists on the opposite side to the side where the rear object that caused the warning condition to be satisfied exists (step 325 "Yes"), A sound warning is issued for the object to be avoided that exists on the opposite side (step 335), and the rear warning is issued in a manner other than sound (step 340). even if an object to be avoided that is different from the object to be avoided that is present on the opposite side is present on the same side as the side on which the rear object that satisfied the warning condition is present, no warning is issued using sound for the object to be avoided that is present on the same side. It is structured as follows.

[0009] When the warning condition is met, the driver is likely to check the rear object by looking at the side mirror on the side where the rear object that triggered the warning condition is located. As a result, the driver's attention to the side opposite the side where the rear object that triggered the warning condition is located decreases. If an object to be avoided is located on the opposite side, the driver may not notice this object to be avoided.

[0010] Therefore, when the rear condition is satisfied and an object to be avoided exists on the opposite side to the side where the rear object for which the warning condition is satisfied exists, the device of the present invention issues a warning using sound for the object to be avoided on the opposite side, thereby increasing the possibility that the driver will be made aware of an object to be avoided that the driver has not noticed.

[0011] Furthermore, when there are objects to be avoided on both the same side and the opposite side of the rear object that has satisfied the warning condition, the driver is more likely to notice the "object to be avoided on the same side" than the "object to be avoided on the opposite side." This is because the driver looks at the side mirror on the side where the rear object is located. Therefore, when the rear condition is satisfied and there are objects to be avoided on both the same side and the opposite side of the rear object, the device of the present invention issues an alarm using sound for the object to be avoided on the opposite side of the rear object, but does not issue an alarm using sound for the object to be avoided on the same side as the rear object. This reduces the possibility that the driver will be unable to determine which side to pay attention to and further enables the driver to focus their attention on the object to be avoided on the side where the driver's attention is reduced. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic system configuration diagram of a driving assistance device according to an embodiment of the present invention; [Figure 2] 1 is an explanatory diagram illustrating an outline of an operation of a driving assistance device according to an embodiment of the present invention; [Figure 3] 2 is a flowchart of a warning routine executed by a CPU of the ECU shown in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] As shown in FIG. 1, a driving assistance device 10 according to this embodiment (hereinafter referred to as "the device 10") is applied to a vehicle VA.

[0014] The device 10 includes the components shown in FIG. 1. In this specification, "ECU 20" refers to an electronic control device that includes a microcomputer as its main component. The ECU 20 is also referred to as a control unit, a controller, and a computer. The microcomputer includes a CPU (processor), a ROM, a RAM, an interface, and the like. The functions realized by the ECU 20 may be realized by multiple ECUs.

[0015] The front camera 22 captures a front image by capturing an image of the scenery in front of the vehicle VA. The rear camera 24 captures a rear image by capturing an image of the scenery behind the vehicle VA. The ECU 20 captures a front image and a rear image from the front camera 22 and the rear camera 24, respectively. The ECU 20 detects an object present in front of the vehicle VA based on the front image, and detects an object present behind the vehicle VA based on the rear image.

[0016] The vehicle speed sensor 26 measures the vehicle speed Vs, which indicates the speed of the vehicle VA. The steering angle sensor 28 measures the steering angle θ of the steering wheel of the vehicle VA. The ECU 20 acquires the measured values ​​of the vehicle speed sensor 26 and the steering angle sensor 28.

[0017] The left speaker 30 is disposed on the left side of the interior of the vehicle VA and emits a predetermined warning sound. The right speaker 32 is disposed on the right side of the interior of the vehicle VA and emits a predetermined warning sound. The left indicator 34 is disposed on the left side mirror LSM in a position visible to the driver seated in the driver's seat of the vehicle VA and is an indicator for visually notifying the driver that there is a rear object to the left rear of the vehicle VA. The right indicator 36 is disposed on the right side mirror RSM in a position visible to the driver seated in the driver's seat of the vehicle VA and is an indicator for visually notifying the driver that there is a rear object to the right rear of the vehicle VA.

[0018] As an example, the left indicator 34 and the right indicator 36 are disposed on the ends of the left side mirror LSM and the right side mirror RSM, respectively.

[0019] (Overview of operation) The device 10 issues a rearward warning for a rearward object when a warning condition is met that includes at least a condition that a rearward object RO is present in either the right rearward side area RSA or the left rearward side area LSA behind the vehicle VA. When a warning condition is met for a rearward object RO present in the right rearward side area RSA, the device 10 issues a rearward warning by activating (illuminating) the right indicator 36. When a warning condition is met for a rearward object RO present in the left rearward side area LSA, the device 10 issues a rearward warning by activating (illuminating) the left indicator 34.

[0020] When the warning condition is met, the device 10 determines whether a forward condition is met, that is, the object to be avoided EO is present on the opposite side to the side where the rearward object RO, which has met the warning condition, is present. When the warning condition and the forward condition are met, the device 10 issues a warning using sound for the object to be avoided EO, which has met the forward condition, and also issues a rearward warning. In detail, the device 10 issues a warning sound from the speaker of the left speaker 30 and the right speaker 32, which is on the side where the object to be avoided EO, which has met the forward condition, is present (i.e., the side opposite to the side where the rearward object RO, which has met the warning condition, is present).

[0021] When the warning condition and the forward condition are satisfied, the device 10 does not issue an audible warning for the object to be avoided EO, even if the object to be avoided EO is on the same side as the rear object RO that satisfied the warning condition. As a result, an audible warning is issued only for the object to be avoided that is on the side where the driver's attention is reduced. This reduces the possibility that the driver will be unable to identify which side to pay attention to, and further enables the driver to focus their attention on the object to be avoided that is on the side where the driver's attention is reduced.

[0022] Here, the object to be avoided EO is an object that exists in front of the vehicle VA and that causes the vehicle VA to change its traveling direction in order to avoid contact.

[0023] The present device 10 recognizes, as objects to be avoided EO, objects that exist in the predicted travel area PA of the vehicle VA, and objects that do not exist in the predicted travel area PA but will enter the predicted travel area PA before the vehicle VA passes through. The predicted travel area PA is an area that the vehicle VA is predicted to pass through. The present device 10 determines a predicted path PP based on the vehicle speed Vs and the steering angle θ, and determines the predicted travel area PA based on the predicted path PP. It is desirable that the width of the predicted travel area PA be set to approximately the width of the vehicle VA. The area to the left of the predicted path PP as seen from the vehicle VA is referred to as the "left predicted travel area LPA," and the area to the right of the predicted path PP as seen from the vehicle VA is referred to as the "right predicted travel area RPA."

[0024] In the example shown in Figure 2, the rear object RO, which satisfies the rear condition, is present in the right rear side area RSA, and the object to be avoided EO1 is present in the left predicted travel area LPA. Therefore, the warning condition and the front condition are satisfied. The device 10 issues an audible warning from the left speaker 30 and activates the right indicator 36. In the example shown in Figure 2, the object to be avoided EO2 is present in the right predicted travel area RPA, but the device 10 does not issue an audible warning from the right speaker 32.

[0025] (Specific operation) The CPU of the ECU 20 of the present device 10 executes the routine shown in the flowchart of FIG. 3 every time a predetermined time period elapses.

[0026] <Alarm Routine> When an appropriate time arrives, the CPU starts the process from step 300 in Fig. 3, and the process proceeds to step 305. In step 305, the CPU determines whether the vehicle speed Vs is equal to or greater than a threshold vehicle speed Vsth.

[0027] If the vehicle speed Vs is equal to or greater than the threshold vehicle speed Vsth, the CPU determines "Yes" in step 305, and the process proceeds to step 310. In step 310, the CPU determines whether a rearward object RO is present in either the right rearward side area RSA or the left rearward side area LSA, based on the rearward image.

[0028] If a rearward object RO is present in either the right rear-side area RSA or the left rear-side area LSA, the CPU determines "Yes" in step 310, and the process proceeds to step 315. In step 315, the CPU determines whether the TTC (Time To Collision) of the rearward object RO is equal to or less than a threshold time Tth. The CPU obtains the relative speed Vr of the rearward object RO with respect to the vehicle VA based on multiple rear images. The CPU obtains the TTC by dividing the distance between the rearward object RO identified based on the rear images and the vehicle VA by the relative speed Vr.

[0029] If the TTC of the rear object RO is equal to or less than the threshold time Tth, the warning condition is met. In this case, the CPU determines "Yes" in step 315, and the process proceeds to step 320.

[0030] In step 320, the CPU determines whether or not there is an object to be avoided EO based on the forward image. Examples of objects to be avoided EO include fallen objects, pedestrians, bicycles, vehicles, motorcycles, utility poles, trees, signs, and steps.

[0031] If an object to be avoided EO exists, the CPU determines "Yes" in step 320, and the process proceeds to step 325. In step 325, the CPU determines whether or not an object to be avoided EO exists in an area (hereinafter referred to as "opposite area") on the opposite side of the left predicted travel area LPA and the right predicted travel area RPA from the side where the rear object RO that has satisfied the warning condition exists.

[0032] If an object to be avoided EO exists in the opposite area, the CPU determines “Yes” in step 325 and the process proceeds to step 330 .

[0033] In step 330, the CPU determines whether the object to be avoided EO in the opposite region is moving based on the multiple rear images. If the object to be avoided EO in the opposite region is moving, the forward condition is met. In this case, the CPU determines "Yes" in step 330 and executes steps 335 and 340.

[0034] Step 335: The CPU issues a warning using sound for the avoidance target object EO for which the forward condition is satisfied (i.e., the avoidance target object EO present in the opposite area). In detail, the CPU causes the speaker on the side where the avoidance target object EO for which the forward condition is satisfied is present, out of the left speaker 30 and the right speaker 32, to emit a warning sound. Step 340: The CPU activates one of the left indicator 34 and the right indicator 36, whichever indicator is on the side where the rear object RO for which the warning condition is met is present. Thereafter, the process proceeds to step 395, where the CPU temporarily ends this routine.

[0035] When the warning condition and the forward condition are met, even if an object to be avoided EO is present in the area of ​​the left predicted traveling area LPA or the right predicted traveling area RPA on the same side as the side where the rear object that caused the warning condition to be met is present (hereinafter referred to as the "same side area"), no warning is issued using sound for the object to be avoided EO.

[0036] When the process proceeds to step 330 , if the “object to be avoided EO existing in the opposite region” has not moved, the CPU determines “No” in step 330 and the process proceeds to step 345 .

[0037] In step 345, the CPU determines whether the number N1 of objects to be avoided EO present in the opposite area (hereinafter referred to as the "first object number N1") is equal to or greater than the threshold number Nth.

[0038] If the first object number N1 is equal to or greater than the threshold number Nth, the forward condition is met. In this case, the CPU determines "Yes" in step 345, and the process proceeds to step 335.

[0039] If the first object number N is less than the threshold number Nth, the forward condition is not met. In this case, the CPU determines "No" in step 345, and the process proceeds to step 350. In step 350, the CPU determines whether or not an avoidance target object EO exists in the same side region.

[0040] If an object to be avoided EO exists in the same side region, the CPU determines "Yes" in step 350, and the process proceeds to step 355. In step 355, the CPU determines whether the object to be avoided EO existing in the same side region is moving.

[0041] If the object to be avoided EO present in the same side region is moving, the CPU determines "Yes" in step 355, and the process proceeds to step 360. In step 360, the CPU issues a warning using sound for the object to be avoided EO present in the same side region. Specifically, the CPU causes the speaker corresponding to the same side region, out of the left speaker 30 and the right speaker 32, to emit a warning sound. Thereafter, the process proceeds to step 340.

[0042] If the object to be avoided EO present in the same side region has not moved when the process proceeds to step 355, the CPU determines "No" in step 355, and the process proceeds to step 365. In step 365, the CPU determines whether the number N2 of objects to be avoided EO present in the same side region (hereinafter referred to as the "second object number N2") is equal to or greater than the threshold number Nth.

[0043] If the second object number N2 is equal to or greater than the threshold number Nth, the CPU determines "Yes" in step 365 and issues a sound warning to the avoidance target object EO that exists in the same side area in step 360. Thereafter, the process proceeds to step 340.

[0044] If the second object number N2 is less than the threshold number Nth, the CPU determines "No" in step 365 and proceeds to step 340 without issuing an alarm using sound.

[0045] The forward condition is not met if no object to be avoided EO exists in the opposite area when the process proceeds to step 325. In this case, the CPU determines “No” in step 325 and the process proceeds to step 350.

[0046] When the process proceeds to step 350 , if there is no object to be avoided EO in the same side area, the CPU determines “No” in step 350 and the process proceeds to step 340 .

[0047] If no object to be avoided EO exists when the process proceeds to step 320 , the CPU determines “No” in step 320 and the process proceeds to step 340 .

[0048] If the vehicle speed Vs is less than the threshold vehicle speed Vsth ("No" in step 305), if the rearward object RO does not exist ("No" in step 310), or if the TTC of the rearward object RO is longer than the threshold time Tth ("No" in step 315), the process proceeds to step 395, where the CPU temporarily ends this routine. As a result, no rearward warning is issued.

[0049] According to this embodiment, when the warning condition and the forward condition are both satisfied, a warning using sound is issued for an object to be avoided EO that exists in the opposite area, and a rear warning is also issued in a manner other than sound, but even if an object to be avoided EO exists in the same side area, a warning using sound is not issued for that object to be avoided EO. This reduces the possibility that the driver will be unable to identify which side to pay attention to due to warning sounds being issued from two directions, and further enables the driver to pay attention to the object to be avoided on the side where the driver's attention is declining.

[0050] Furthermore, when the warning condition is met but the forward condition is not met, a sound warning is issued for the object to be avoided EO that exists in the same side area, thereby increasing the possibility that the driver will notice the object to be avoided EO that exists in the same side area.

[0051] When an object to be avoided EO is moving, the driver needs to pay a higher level of attention to the object to be avoided EO than when the object to be avoided EO is stationary. When an object to be avoided EO is moving toward the vehicle VA, the time it takes to come into contact with the vehicle VA is shorter than when an object to be avoided EO is stationary, so the driver needs to pay a higher level of attention. Furthermore, a moving object to be avoided EO may suddenly change its direction of movement, so the driver needs to pay a higher level of attention. Furthermore, the greater the number of objects to be avoided present in the opposite area, the greater the level of attention the driver needs to pay. Therefore, in this embodiment, the forward condition is satisfied when an object to be avoided EO in the opposite area is moving or when the number N1 of objects to be avoided EO in the opposite area is equal to or greater than the threshold number Nth. This reduces the possibility that an audible warning will be issued when the driver does not need to pay much attention, thereby reducing the possibility that the driver will find the audible warning annoying.

[0052] (First Modification) In the above embodiment, the alarm condition is met when both the first condition that a rear object RO is present in either the left rear lateral area LSA or the right rear lateral area RSA, and the second condition that the TTC of the rear object RO is equal to or less than the threshold time Tth, are met, but this is not limited to this.

[0053] The warning condition does not have to include the second condition. The first condition only needs to be a condition that a rear object RO is present in at least one of the left rear lateral area LSA and the right rear lateral area RSA. In other words, the warning condition only needs to include a condition that a rear object RO is present in at least one of the left rear lateral area LSA and the right rear lateral area RSA.

[0054] When the first condition is that a rear object RO is present in at least one of the left rear lateral area LSA and the right rear lateral area RSA, the warning condition is also satisfied when a rear object RO is present in each of the left rear lateral area LSA and the right rear lateral area RSA. In this case, the rear object RO with the smallest TTC is identified as the "rear object RO that has satisfied the warning condition." That is, the CPU identifies the area opposite to the side where the rear object RO with the shorter TTC is present, of the left predicted traveling area LPA and the right predicted traveling area RPA, as the opposite area, and determines whether the forward condition is satisfied.

[0055] (Second Modification) The forward condition may include at least a condition that an object to be avoided EO is present in the opposite region. Furthermore, the condition for issuing a sound warning for an object to be avoided EO present in the same side region when the warning condition is met but the forward condition is not met may also include at least a condition that an object to be avoided EO is present in the same side region.

[0056] (Third Modification) In the above embodiment, the CPU detects an object based on the forward image and the rearward image, but this is not limiting. For example, the device 10 may include at least one of millimeter-wave radar, lidar, and sonar, and the CPU may detect an object based on the detection results of at least one of the millimeter-wave radar, lidar, and sonar.

[0057] (Fourth Modification) In the rear warning, either the left indicator 34 or the right indicator 36 is activated, but the rear warning is not limited to this. In the rear warning, a display element that draws the driver's attention to the rear object RO that has satisfied the rear condition may be displayed on a display device disposed in the passenger compartment of the vehicle VA and / or a head-up display of the vehicle VA.

[0058] The device 10 can be applied to vehicles such as internal combustion engine vehicles, hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, and electric vehicles. Furthermore, the device 10 can also be applied to autonomous vehicles. [Explanation of symbols]

[0059] 10...driving assistance device, 22...front camera, 24...rear camera, 30...left speaker, 32...right speaker, 34...left indicator, 36...right indicator.

Claims

1. 1. A driving assistance device that issues a rear warning regarding a rear object when a warning condition including at least a condition that a rear object is present on at least one of the right and left sides of a vehicle is satisfied, comprising: The driving assistance device When the warning condition is satisfied and a forward condition is also satisfied, the forward condition including at least a condition that an avoidance target object that exists in front of the vehicle and that causes the vehicle to change its traveling direction to avoid contact with the vehicle exists on the opposite side to the side where the rear object that caused the warning condition to be satisfied exists, a warning using sound is given for the object to be avoided that exists on the opposite side, and the rear warning is given in a manner other than sound; even if an object to be avoided that is different from the object to be avoided that is present on the opposite side is present on the same side as the side on which the rear object that satisfied the warning condition is present, no warning is issued using sound for the object to be avoided that is present on the same side. A driving assistance device configured as follows.

2. The driving assistance device according to claim 1, The driving assistance device When the warning condition is satisfied but the forward condition is not satisfied, if the object to be avoided is present on the same side as the rear object that caused the warning condition to be satisfied, a warning is given using sound for the object to be avoided that is present on the same side. A driving assistance device configured as follows.

3. The driving assistance device according to claim 2, Speakers are provided on the right and left sides of the vehicle interior, When issuing a warning using sound for the object to be avoided, the driving assistance device is configured to emit the sound from a speaker on a side where the object to be avoided is present. Driving assistance device.

4. The driving assistance device according to claim 1, The driving assistance device is configured to determine that the forward condition is met when an object to be avoided on the opposite side is moving, or when the number of objects to be avoided on the opposite side is equal to or greater than a threshold number.

5. The driving assistance device according to claim 1, the driving assistance device is configured to issue the rear warning by activating one of a right indicator provided on a right side mirror of the vehicle and a left indicator provided on a left side mirror of the vehicle, the indicator being on a side where the rear object for which the warning condition is satisfied is present. Driving assistance device.

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