Driving support device

Abstract

To provide a driving support device that issues an alarm when a three-dimensional object is present in an oblique rear of the own vehicle and that is capable of suppressing an unnecessary alarm.SOLUTION: A driving support device comprises: an on-vehicle sensor for acquiring information about a target around the own vehicle; and a processor that controls a notifying device to issue an alarm when a three-dimensional object exists within an alarm object area in an oblique rear of the own vehicle. When the own vehicle is traveling on a center portion of a first lane, the processor sets a lateral distance between a first long side and the own vehicle to a first predetermined value and sets a lateral distance between a second long side and the own vehicle to a second predetermined value. When the own vehicle moves from a center portion in a width direction of the first lane to a side of a second lane adjacent to the first lane, the processor sets a lateral distance between the first long side and the own vehicle to the first predetermined value and sets a lateral distance between the second long side and the own vehicle to a value smaller than the second predetermined value.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a driving assistance device that issues a warning to a driver of a vehicle when a three-dimensional object is present within a predetermined area diagonally rearward of the vehicle. [Background technology]

[0002] A driving support device has been proposed that issues a warning to the driver of the vehicle when a three-dimensional object is present within a predetermined area diagonally rearward of the vehicle (see, for example, Patent Document 1 below). This driving support device (hereinafter referred to as the "conventional device") emits radio waves to the rear of the vehicle (diagonally rear right and diagonally rear left). When a three-dimensional object is present diagonally rearward of the vehicle, the radio waves emitted from the conventional device are reflected by the three-dimensional object, and the radio waves (reflected waves) travel toward the vehicle. The conventional device receives the reflected waves. The conventional device calculates physical quantities related to the three-dimensional object (such as the position of the three-dimensional object relative to the vehicle and the speed of the three-dimensional object relative to the vehicle) based on physical quantities related to the emitted radio waves and the received reflected waves. When the conventional device determines that a three-dimensional object is approaching the vehicle based on the calculation results, it issues a predetermined warning to the driver. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-258426 Summary of the Invention

[0004] As described above, the conventional device emits radio waves to the rear of the vehicle to detect three-dimensional objects. In the conventional device, the reachable area of ​​the emitted radio waves (the radius of the sector-shaped area extending diagonally rearward of the vehicle (the reachable distance of the radio waves)) corresponds to the area for which the above-mentioned warning is issued (hereinafter referred to as the warning target area). In general, the reachable distance of the radio waves is greater than the width of a standard driving lane (3.5 meters). For example, the reachable distance of the radio waves is approximately 10 meters.

[0005] For example, when the vehicle is traveling in the first lane of a road consisting of a first lane (left lane), a second lane (center lane), and a third lane (right lane), the radio waves emitted from the vehicle to the right rear reach at least the vicinity of the boundary between the second lane and the third lane. In other words, in a plan view, the warning target area overlaps with the second lane.

[0006] For example, when a driver attempts to move his / her vehicle from the first lane to the second lane (change lanes) in order to overtake a preceding vehicle, a situation may arise in which another vehicle is present in an area of ​​the warning target area that overlaps with the second lane. In this situation, the conventional device detects the other vehicle and issues a warning. This allows the driver to cancel (or postpone) the lane change in order to avoid contact between the other vehicle and his / her vehicle.

[0007] On the other hand, if there is no other vehicle in the second lane, no alarm is issued. Therefore, when the driver starts to move the vehicle toward the second lane, the alarm target area also moves in parallel to the right lateral direction along with the movement (lateral displacement) of the vehicle. In the process, the edge of the alarm target area may overlap the third lane. A scene is assumed in which another vehicle is present within the edge of the alarm target area (within the area overlapping the third lane). In this scene, the conventional device detects the other vehicle and issues an alarm. In this scene, the other vehicle is unlikely to interfere with the movement (lane change) of the vehicle from the first lane to the second lane. Despite this, the conventional device issues an alarm. Therefore, the driver of the vehicle may find the alarm annoying.

[0008] An object of the present invention is to provide a driving assistance device that issues an alarm when a three-dimensional object is present diagonally rearward of the vehicle, and that is capable of suppressing issuance of an alarm that is actually unnecessary.

[0009] In order to solve the above problems, a driving assistance device (1) according to the present invention comprises: An on-board sensor (20) for acquiring information regarding targets present around a host vehicle (V); a processor (10) for controlling an alarm device (30) to issue an alarm when a three-dimensional object is present in a belt-shaped alarm target area (Aa, Ab) extending in the front-rear direction obliquely behind the vehicle; Equipped with. The processor, When the host vehicle is traveling in the center in the width direction of the first lane (L1), a lateral distance (D3a, D3b) between the host vehicle and a first long side (E3a, E3b) which is a long side of the warning target area and is located on the host vehicle side is set to a first predetermined value (Δd3), and a lateral distance (D4a, D4b) between the host vehicle and a second long side (E4a, E4b) which is a long side of the warning target area and is located on the opposite side of the host vehicle is set to a second predetermined value (Δd4[0]); When the host vehicle is displaced from the center of the first lane in the width direction to a second lane (L2a, L2b) adjacent to the first lane, the lateral distance between the first long side and the host vehicle is set to the first predetermined value, and the lateral distance between the second long side and the host vehicle is set to a value (Δd4[ΔYa], Δd4[ΔYb]) smaller than the second predetermined value. It is configured as follows.

[0010] Further, the driving assistance method according to the present invention comprises: an information acquisition step of acquiring information about targets existing around the host vehicle; a warning step of controlling the warning device to issue a warning when a three-dimensional object is present in a belt-shaped warning target area extending in a front-rear direction obliquely behind the vehicle; Includes. The notification step includes: a step of setting a lateral distance between the host vehicle and a first long side of the warning target area located on the host vehicle side to a first predetermined value when the host vehicle is traveling in a center portion in a width direction of a first lane, and setting a lateral distance between the host vehicle and a second long side of the warning target area located on the opposite side to the host vehicle to a second predetermined value; when the host vehicle is displaced from a center portion in a width direction of the first lane to a second lane adjacent to the first lane, setting a lateral distance between the first long side and the host vehicle to the first predetermined value, and setting a lateral distance between the second long side and the host vehicle to a value smaller than the second predetermined value; The present invention is configured to include:

[0011] In addition, the driving assistance program according to the present invention is The vehicle's computer an information acquisition step of acquiring information about targets existing around the host vehicle; a warning step of controlling the warning device to issue a warning when a three-dimensional object is present in a belt-shaped warning target area extending in a front-rear direction obliquely behind the vehicle; Execute the command. The notification step includes: a step of setting a lateral distance between the host vehicle and a first long side of the warning target area located on the host vehicle side to a first predetermined value when the host vehicle is traveling in a center portion in a width direction of a first lane, and setting a lateral distance between the host vehicle and a second long side of the warning target area located on the opposite side to the host vehicle to a second predetermined value; when the host vehicle is displaced from a center portion in a width direction of the first lane to a second lane adjacent to the first lane, setting a lateral distance between the first long side and the host vehicle to the first predetermined value, and setting a lateral distance between the second long side and the host vehicle to a value smaller than the second predetermined value; The present invention is configured to include:

[0012] When a vehicle to which a conventional device is applied is displaced laterally, the warning area is displaced laterally (translated) in the same manner as the displacement of the vehicle without changing the size of the warning area. Therefore, a part of the warning area may protrude into the third lane (the lane opposite the first lane) adjacent to the second lane, and as the amount of lateral displacement of the vehicle increases, the amount of protrusion of the warning area into the third lane (the width of the part overlapping the third lane) increases.

[0013] In contrast, in the driving assistance device according to the present invention, when the host vehicle is displaced laterally from the center in the width direction (lateral direction) of the first lane (hereinafter referred to as the "neutral position"), the lateral distance between the host vehicle and the first long side is maintained constant, but the lateral distance between the host vehicle and the second long side is shortened. In other words, the width (lateral size) of the warning target area is reduced. Therefore, when the host vehicle is displaced laterally from the neutral position, the warning target area is prevented from protruding into the third lane (or the amount of protrusion is increased). This prevents an unnecessary warning from being issued.

[0014] In one aspect of the present invention, a driving assistance device includes: The processor obtains the amount of lateral displacement when the vehicle displaces from the center in the width direction of the first lane toward the second lane, and sets the lateral distance between the second long side and the vehicle to a value obtained by subtracting the amount of lateral displacement from the second predetermined value.

[0015] According to this, even if the host vehicle is displaced laterally from the neutral position, the position of the second long side with respect to the road surface remains unchanged.

[0016] In addition, in a driving assistance device according to another aspect of the present invention, The processor is configured to set the second predetermined value based on a width of the first lane.

[0017] In this embodiment, the processor assumes that the width of the second lane is the same as the width of the first lane, and sets the second predetermined value based on the width of the first lane. For example, the second predetermined value is set to be equal to the width of the first lane or a value slightly larger than the width of the first lane (a value to which a predetermined margin is added). This increases the possibility that the alarm target area is set so that the second long side is located within the second lane. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a block diagram of a driving assistance device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing the detectable range. [Diagram 3] FIG. 3 is a plan view for explaining an alarm target area when the host vehicle is displaced rightward from the neutral position. [Figure 4] FIG. 4 is a plan view for explaining an alarm target area when the host vehicle is displaced leftward from the neutral position. [Diagram 5] FIG. 5 is a flowchart of a program executed by the CPU to realize the function of setting an alarm target area based on the amount of lateral displacement of the vehicle. [Figure 6] FIG. 6 is a plan view for explaining the difference between the maximum value of the width of the warning target region in the driving assistance device according to the first embodiment of the present invention and the maximum value of the width of the warning target region in the driving assistance device according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] First Embodiment (Summary) As shown in Fig. 1, a driving support device 1 according to a first embodiment of the present invention is applied to a vehicle V (hereinafter referred to as "own vehicle") equipped with an automatic driving function. The driving support device 1 has a function (alarm function) of issuing a predetermined alarm when it detects the presence of a three-dimensional object (another vehicle) diagonally behind the own vehicle in a state where the automatic driving function is disabled (a state where the driver is actively performing driving operations).

[0020] (Specific configuration) As shown in FIG. 1, the driving assistance device 1 includes an ECU 10, an in-vehicle sensor 20, and a notification device 30.

[0021] The ECU 10 is equipped with a microcomputer including a CPU 10a, a ROM 10b (rewritable non-volatile memory), a RAM 10c, a timer 10d, etc. The CPU realizes various functions by executing programs (instructions) stored in the ROM. The ECU 10 is connected to other ECUs via a CAN (Controller Area Network).

[0022] The on-board sensor 20 includes a millimeter wave radar 21, a sonar 22, and a camera 23.

[0023] The millimeter wave radar 21 includes a transmission / reception unit and a signal processing unit. The transmission / reception unit emits millimeter wave band radio waves (hereinafter referred to as "millimeter waves") diagonally to the right rear and left rear of the vehicle, and receives millimeter waves (reflected waves) reflected by three-dimensional objects (other vehicles, pedestrians, etc.) located within the emission range. The signal processing unit recognizes the distance between the vehicle and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle, etc. based on the time from when the transmission / reception unit emits the millimeter waves to when it receives the reflected waves, the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation of the reflected waves, etc., and provides the recognition result to the ECU 10.

[0024] The sonar 22 intermittently emits ultrasonic waves diagonally to the right rear and left rear of the vehicle and receives ultrasonic waves (reflected waves) reflected by a three-dimensional object. The sonar 22 recognizes the distance between the vehicle and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle, etc. based on the time from when the ultrasonic waves are transmitted to when the reflected waves are received, and provides the recognition result to the ECU 10.

[0025] The camera 23 includes an imaging device and an image analysis device. The imaging device has, for example, a built-in CCD. The imaging device is installed at the front of the vehicle and faces the front of the vehicle. The imaging device captures images of the front view of the vehicle at a predetermined frame rate to obtain image data. The image analysis device analyzes the image data obtained from the imaging device and recognizes objects existing around the vehicle from the images. The image analysis device recognizes, for example, lane marks (division lines, curbs, medians, etc. that divide the driving lanes) and provides the recognition results to the ECU 10.

[0026] As shown in Figs. 2A and 2B, the areas Ma and Mb (ranges that the millimeter waves can reach) from which the millimeter waves of the millimeter wave radar 21 are radiated are substantially sector-shaped in plan view. The areas Ma and Mb overlap not only the driving lanes L2a and L2b adjacent to the driving lane L1 in which the vehicle is traveling, but also the driving lanes L3a and L3b adjacent to the driving lanes L2a and L2b. Meanwhile, the areas Sa and Sb (ranges that the ultrasonic waves can reach) from which the sonar 22 radiates ultrasonic waves also have a substantially sector-shaped shape in plan view. The areas Sa and Sb overlap the areas Ma and Mb. The areas Sa and Sb are narrower than the areas Ma and Mb. The sonar 22 is used to improve the detection accuracy of a three-dimensional object relatively close to the vehicle.

[0027] The notification device 30 includes an image display device and an audio device. The image display device displays an image based on an image display command received from the ECU 10. The audio device reproduces a sound based on a sound reproduction command received from the ECU 10.

[0028] (Alarm function) The ECU 10 can detect the presence of a three-dimensional object diagonally behind the vehicle based on the fused information obtained from the on-board sensor 20. The area (maximum range) in which the ECU 10 can detect a three-dimensional object is called the "detectable area DTa, DTb". As shown in FIG. 2, the detectable areas DTa, DTb approximately coincide with the areas Ma, Mb. The ECU 10 sets warning target areas Aa, Ab, which will be described later, in the detectable areas DTa, DTb, respectively, and controls the notification device 30 so that a predetermined warning is issued when a three-dimensional object (another vehicle or a pedestrian) exists in the warning target areas Aa, Ab. Specifically, the ECU 10 causes the notification device 30 to display a predetermined image and play a predetermined sound.

[0029] The warning target areas Aa and Ab are rectangular (belt-shaped) extending in the front-rear direction (longitudinal direction) at the right rear and left rear of the vehicle in a plan view. That is, the warning target area Aa corresponds to the area surrounded by the front side E1a, the rear side E2a, the left side E3a, and the right side E4a. The warning target area Ab corresponds to the area surrounded by the front side E1b, the rear side E2b, the right side E3b, and the left side E4b.

[0030] As shown in FIG. 3A, the ECU 10 sets the vertical distance D1a and distance D2a between the rear end of the vehicle and the front edge E1a and rear edge E2a to a predetermined value Δd1 and a predetermined value Δd2, respectively. The ECU 10 also sets the horizontal distance D3a between the right end (right side surface) of the vehicle and the left edge E3a to a predetermined value Δd3. The predetermined values ​​Δd1, Δd2, Δd3 are stored in the ROM 10b. That is, these values ​​are fixed values. In contrast, the value assigned to the horizontal distance D4a between the right end (right side surface) of the vehicle and the right edge E4a is a variable value. The ECU 10 sets the distance D4a as follows:

[0031] Specifically, the ECU 10 acquires (calculates) the amount of displacement ΔYa of the position of the center of gravity of the vehicle, which is the amount of displacement from the center in the width direction of the travel lane L1 (hereinafter referred to as the "neutral position") to the right, based on information acquired from the camera 23 (the positions (coordinates) of the lane marks in an image acquired by photographing the view in front of the vehicle). Next, the ECU 10 acquires a calculated value Δd4[ΔYa] based on the following calculation formula (1), and sets the distance D4a to the calculated value Δd4[Ya]. Δd4[ΔYa]=Δd3+W―ΔYa ···(1) Here, the predetermined width W (fixed value) is, for example, "4 meters" (a value slightly larger than the width of a standard driving lane (3.5 meters)).

[0032] In addition, in a situation where the center of gravity of the vehicle is displaced leftward from the neutral position, the ECU 10 regards the displacement amount ΔYa as "0". Therefore, when the center of gravity of the vehicle is in the neutral position (and the area to the left of it) (ΔYa=0), the width ΔWAa (=D4a-D3a) of the warning target area Aa is maximum (see FIG. 4(B)). When the center of gravity of the vehicle is in the neutral position, the right side E4a of the warning target area Aa is located, for example, slightly to the left (within the driving lane L2a) of the right end of the driving lane L2a adjacent to the right side of the driving lane L1 (see FIG. 3(A)). As shown in FIG. 3(B), when the center of gravity of the vehicle is displaced rightward from the neutral position, the warning target area Aa is reduced in its width direction. The difference between the width of the warning target area Aa before reduction (when the center of gravity is in the neutral position) and the width of the warning target area Aa after reduction is the same as the displacement amount ΔYa. Therefore, even if the host vehicle is displaced rightward from the neutral position, the lateral position of the right side E4a of the warning area Aa relative to the road surface remains unchanged.

[0033] Furthermore, the ECU 10 sets the warning target area Ab in the same procedure as the procedure for setting the warning target area Aa described above. That is, the ECU 10 sets the distances D1b and D2b to the predetermined values ​​Δd1 and Δd2, respectively, as shown in FIG. 3B (see FIG. 4A). The ECU 10 sets the distance D3b to the predetermined value Δd3. The ECU 10 also obtains a calculated value Δd4[ΔYb] based on the following calculation formula (2) defined using the amount of leftward displacement ΔYb of the center of gravity of the vehicle from the neutral position, and sets the distance D4b to the calculated value Δd4[ΔYb]. Δd4[ΔYb]=Δd3+W―ΔYb (2)

[0034] In addition, in a situation where the center of gravity of the vehicle is displaced from the neutral position to the right, the ECU 10 regards the displacement amount ΔYb as "0". Therefore, when the center of gravity of the vehicle is in the neutral position (and the area to the right of it) (ΔYb=0), the width ΔWAb (=D4b-D3b) of the warning target area Ab is maximum (see FIG. 3(B)). When the center of gravity of the vehicle is in the neutral position, the left side E4b of the warning target area Ab is located, for example, slightly to the right (within the driving lane L2b) of the left end of the driving lane L2b adjacent to the left side of the driving lane L1 (see FIG. 4(A)). As shown in FIG. 4(B), when the center of gravity of the vehicle is displaced from the neutral position to the left, the warning target area Ab is reduced in its width direction. The difference between the width of the warning target area Ab before reduction (when the center of gravity is in the neutral position) and the width of the warning target area Ab after reduction is the same as the displacement amount ΔYb. Therefore, even if the host vehicle is displaced leftward from the neutral position, the lateral position of the left side E4b of the warning target area Ab relative to the road surface remains unchanged.

[0035] Next, with reference to FIG. 5, a program PR1 executed by the CPU 10a (hereinafter simply referred to as "CPU") of the ECU 10 to realize the function of setting the warning target areas Aa, Ab based on the above-mentioned displacement amounts ΔYa, ΔYb will be described.

[0036] When the alarm function is enabled, the CPU starts the execution of the program PR1. The CPU starts the execution of the program PR1 from step 100 and proceeds to step 101.

[0037] The CPU executes an initialization process in step 101. Specifically, the CPU sets the distances D1a and D1b to a predetermined value Δd1. The CPU also sets the distances D2a and D2b to a predetermined value Δd2. The CPU also sets the distances D3a and D3b to a predetermined value Δd3. Next, the CPU proceeds to step 102.

[0038] In step 102, the CPU determines whether or not the host vehicle (the center of gravity of the host vehicle) has been displaced to the right from the neutral position based on information acquired from the camera 23. If the CPU determines that the host vehicle has been displaced to the right from the neutral position (102: Yes), the CPU proceeds to step 103. On the other hand, if the CPU does not determine that the host vehicle has been displaced to the right from the neutral position (102: No), the CPU proceeds to step 106.

[0039] The CPU acquires the displacement amount ΔYa in step 103. Next, the CPU advances the process to step 104.

[0040] In step 104, the CPU acquires a calculation value Δd4[ΔYa] (=Δd3+W−ΔYa) based on the arithmetic expression (1) and sets the distance D4a to the calculation value Δd4[Ya]. Next, the CPU proceeds to step 105.

[0041] In step 105, the CPU sets the distance D4b to the maximum value. That is, the CPU regards the displacement amount ΔYb in the arithmetic expression (2) as "0", obtains the calculated value Δd4[0] (=Δd3+W), and sets the distance D4b to the calculated value Δd4[0]. Then, the CPU returns the process to step 102.

[0042] In step 106, the CPU determines whether or not the host vehicle has been displaced leftward from the neutral position based on the information acquired from the camera 23. If the CPU determines that the host vehicle has been displaced leftward from the neutral position (106: Yes), the CPU proceeds to step 107. On the other hand, if the CPU does not determine that the host vehicle has been displaced leftward from the neutral position (106: No), the CPU proceeds to step 110.

[0043] The CPU acquires the displacement amount ΔYb in step 107. Next, the CPU advances the process to step .

[0044] In step 108, the CPU sets the distance D4a to the maximum value. That is, the CPU regards the displacement amount ΔYa in the calculation formula (1) as "0", obtains the calculated value Δd4[0] (=Δd3+W), and sets the distance D4a to the calculated value Δd4[0]. Next, the CPU proceeds to step 109.

[0045] In step 109, the CPU obtains a calculation value Δd4[ΔYb] (=Δd3+W−ΔYb) based on the arithmetic expression (2) and sets the distance D4b to the calculation value Δd4[Yb]. Then, the CPU returns the process to step 102.

[0046] In step 110, the CPU sets the distance D4a to the maximum value. That is, the CPU regards the displacement amount ΔYa in the arithmetic expression (1) as "0", obtains the calculated value Δd4[0] (=Δd3+W), and sets the distance D4a to the calculated value Δd4[0]. Next, the CPU proceeds to step 111.

[0047] In step 111, the CPU sets the distance D4b to the maximum value. That is, the CPU regards the displacement amount ΔYb in the arithmetic expression (2) as "0", obtains the calculated value Δd4[0] (=Δd3+W), and sets the distance D4b to the calculated value Δd4[0]. Then, the CPU returns the process to step 102.

[0048] (effect) In the driving support device 1, when the center of gravity of the vehicle is displaced to the right (left) from the neutral position of the driving lane L1, the lateral distance D3a (D3b) between the right side (left side) of the vehicle and the left side E3a (right side E3b) is kept constant, but the distance D4a (D4b) between the right side (left side) of the vehicle and the right side E4a (left side E4b) is shortened. That is, the width ΔWAa (ΔWAb) of the warning target area Aa (Ab) is reduced. Therefore, when the vehicle is displaced to the right (left) from the neutral position, the warning target area Aa (Ab) is prevented from protruding (or the protruding amount is increased) to the driving lane L3a (L3b). This prevents an unnecessary warning from being issued.

[0049] Second Embodiment (composition) Next, a driving support device 2 according to a second embodiment of the present invention will be described. The configuration of the driving support device 2 is the same as that of the driving support device 1.

[0050] (Alarm function) In the driving assistance device 1, the ECU 10 adopts the value obtained by subtracting the displacement amount ΔYa from the value obtained by adding the predetermined width W to the predetermined value Δd3 as the distance D4a (D4b) regardless of the width of the travel lane. As shown in FIG. 6A, when the width WL of the travel lane is relatively narrower than the predetermined value W, the warning target area Aa (Ab) may protrude into the travel lane L3a (L3b). On the other hand, when the width WL of the travel lane is relatively larger than the predetermined value W (the maximum width of the warning target area Aa, Ab), there is a possibility that a gap (an area where a warning is not issued even if a vehicle or pedestrian exists) may be formed between the right side E4a (E4b) of the warning target area Aa (Ab) and the travel lane L2a (L2b) and the right end (left end) of the travel lane L2a (L2b).

[0051] Therefore, in the driving assistance device 2, the ECU 10 adopts a calculated value W[WL, WV] obtained based on the width WL of the driving lane and the vehicle width WV of the vehicle instead of the predetermined value W as the maximum value of the width of the warning target area Aa, Ab (the width of the warning target area Aa, Ab when the center of gravity of the vehicle is in the neutral position). Specifically, the ECU 10 acquires the width WL of the driving lane L1 based on information acquired from the camera 23. Here, the ECU 10 often cannot acquire the width of the driving lanes L2a, L2b with high accuracy based on the information acquired from the camera 23. Therefore, the ECU 10 adopts the width WL of the driving lane L1 as the width of the driving lanes L2a, L2b. Next, the ECU 10 acquires the calculated value W[WL, WV] (= WAa, WAb) based on the following calculation formula (3). The vehicle width WV is pre-stored in the ROM 10b. W[WL,WV]=WL / 2−WV / 2−Δd3+WL (3)

[0052] Next, the ECU 10 obtains the calculated values ​​Δd4[ΔYa] and Δd4[ΔYb] by applying the calculated values ​​W[WL,WV] (the value obtained by the calculation formula (3)) to the following calculation formulas (4) and (5) which are similar to the calculation formulas (1) and (2) of the first embodiment. Then, the ECU 10 sets the distances D4a and D4b to the calculated values ​​Δd4[ΔYa] and Δd4[ΔYb], respectively. Δd4[ΔYa]=Δd3+W[WL,WV]−ΔYa (4) Δd4[ΔYb]=Δd3+W[WL,WV]−ΔYb (5)

[0053] The distances D1a, D1b, D2a, D2b, D3a, and D3b are set in the same manner as in the first embodiment.

[0054] (effect) According to this embodiment, as shown in FIG. 6B, the right end (left end) of the warning target area Aa (Ab) can be always aligned with the right end (left end) of the driving lane L2a (L2b). That is, the warning target areas Aa, Ab can be prevented from protruding into the driving lanes L3a, L3b. Therefore, unnecessary warnings can be prevented from being issued.

[0055] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention, as described below.

[0056] <Variation 1> In the above embodiment, a three-dimensional object located diagonally behind the vehicle is detected using the millimeter wave radar 21 and the sonar 22. Instead of or in addition to this, a three-dimensional object located diagonally behind the vehicle may be detected using a camera, a LiDAR sensor, or the like that is directed toward the rear of the vehicle.

[0057] <Variation 2> In the above embodiment, the warning target areas Aa and Ab are rectangular and extend in the front-rear direction. When the vehicle is turning (driving on a curved road), the warning target areas Aa and Ab may be curved to follow the road. [Explanation of symbols]

[0058] 1... driving support device, 10... ECU, 20... vehicle-mounted sensor, 30... notification device

Claims

1. An on-board sensor that acquires information about targets present around the vehicle; a processor that controls the alarm device to issue an alarm when a three-dimensional object is present in a belt-shaped alarm target area extending in a front-rear direction obliquely behind the vehicle; A driving assistance device comprising: The processor, When the host vehicle is traveling in a center portion in a width direction of a first lane, a lateral distance between the host vehicle and a first long side of the warning target area located on the host vehicle side is set to a first predetermined value, and a lateral distance between the host vehicle and a second long side of the warning target area located on the opposite side to the host vehicle is set to a second predetermined value, When the host vehicle is displaced from a center portion in a width direction of the first lane to a second lane side adjacent to the first lane, the lateral distance between the first long side and the host vehicle is set to the first predetermined value, and the lateral distance between the second long side and the host vehicle is set to a value smaller than the second predetermined value. A driving assistance device configured as above.

2. The driving assistance device according to claim 1, The processor is configured to obtain the amount of lateral displacement when the vehicle is displaced from the center in the width direction of the first lane toward the second lane, and to set the lateral distance between the second long side and the vehicle to a value obtained by subtracting the amount of lateral displacement from the second predetermined value.

3. The driving support device according to claim 1 or 2, The processor is configured to set the second predetermined value based on a width of the first lane.

4. an information acquisition step of acquiring information about targets existing around the host vehicle; a warning step of controlling the warning device to issue a warning when a three-dimensional object is present in a belt-shaped warning target area extending in a front-rear direction obliquely behind the vehicle; A driving assistance method comprising: The notification step includes: a step of setting a lateral distance between the host vehicle and a first long side of the warning target area located on the host vehicle side to a first predetermined value when the host vehicle is traveling in a center portion in a width direction of a first lane, and setting a lateral distance between the host vehicle and a second long side of the warning target area located on the opposite side to the host vehicle to a second predetermined value; when the host vehicle is displaced from a center portion in a width direction of the first lane to a second lane adjacent to the first lane, setting a lateral distance between the first long side and the host vehicle to the first predetermined value, and setting a lateral distance between the second long side and the host vehicle to a value smaller than the second predetermined value; A driving assistance method comprising:

5. The vehicle's computer an information acquisition step of acquiring information about targets existing around the host vehicle; a warning step of controlling the warning device to issue a warning when a three-dimensional object is present in a belt-shaped warning target area extending in a front-rear direction obliquely behind the vehicle; A driving assistance program for executing The notification step includes: a step of setting a lateral distance between the host vehicle and a first long side of the warning target area located on the host vehicle side to a first predetermined value when the host vehicle is traveling in a center portion in a width direction of a first lane, and setting a lateral distance between the host vehicle and a second long side of the warning target area located on the opposite side to the host vehicle to a second predetermined value; when the host vehicle is displaced from a center portion in a width direction of the first lane to a second lane adjacent to the first lane, setting a lateral distance between the first long side and the host vehicle to the first predetermined value, and setting a lateral distance between the second long side and the host vehicle to a value smaller than the second predetermined value; A driving assistance program configured to include:

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