Driving assistance device, driving assistance method, and program

Abstract

This driving assistance device is mounted on a host vehicle, and comprises: a two-wheeled vehicle detection means for detecting a two-wheeled vehicle traveling on a host vehicle lane that is a lane on which the host vehicle is traveling; an oncoming vehicle detection means for detecting an oncoming vehicle that enters or tries to enter the host vehicle lane from an opposite lane; a collision determination means for determining whether or not the oncoming vehicle may collide with the two-wheeled vehicle; and a warning means for warning a driver of the oncoming vehicle when the oncoming vehicle may collide with the two-wheeled vehicle.

Description

Driving assistance device, driving assistance method, and program

[0001] The present invention relates to a driving assistance device, a driving assistance method, and a program.

[0002] Patent Document 1 discloses a vehicle warning device that prevents a collision between an oncoming right-turning vehicle and a following straight-moving vehicle by notifying the driver of the oncoming right-turning vehicle that there is a following straight-moving vehicle in the blind spot of the vehicle.

[0003] JP 2011-164760 A

[0004] However, the above-mentioned Patent Document 1 is specific to the case where the following straight-moving vehicle is a four-wheeled vehicle, and does not mention the case where the following straight-moving vehicle is a two-wheeled vehicle.

[0005] An object of the present disclosure is to provide a technique for preventing a collision between a motorcycle and another vehicle.

[0006] Provided is a driving assistance device mounted on a host vehicle, the driving assistance device including: two-wheeled vehicle detection means for detecting two-wheeled vehicles traveling in the host vehicle lane, which is the lane in which the host vehicle is traveling; oncoming vehicle detection means for detecting an oncoming vehicle entering or attempting to enter the host vehicle lane from an oncoming lane; collision determination means for determining whether or not the oncoming vehicle is likely to collide with the two-wheeled vehicle; and attention alert means for alerting the driver of the oncoming vehicle when there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle.

[0007] A driving assistance method is provided in which a driving assistance device mounted on a host vehicle detects a two-wheeled vehicle traveling in the host vehicle lane in which the host vehicle is traveling, detects an oncoming vehicle entering or attempting to enter the host vehicle lane from an oncoming lane, determines whether or not the oncoming vehicle is likely to collide with the two-wheeled vehicle, and, if there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle, issues a warning to the driver of the oncoming vehicle.

[0008] A program is provided that causes a driving assistance device mounted on a host vehicle to function as: two-wheeled vehicle detection means that detects two-wheeled vehicles traveling in the host vehicle lane, which is the lane in which the host vehicle is traveling; oncoming vehicle detection means that detects oncoming vehicles that have entered or are attempting to enter the host vehicle lane from an oncoming lane; collision determination means that determines whether or not the oncoming vehicle is likely to collide with the two-wheeled vehicle; and attention warning means that warns the driver of the oncoming vehicle when there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle.

[0009] According to the present disclosure, it is possible to prevent a collision between a two-wheeled vehicle and another vehicle.

[0010] It is a block diagram of a driving support device. It is a control flow of the driving support device. It is a plan view of an intersection. It is a block diagram of a four-wheeled vehicle. It is a control flow of the driving support device.

[0011] The present invention will be described below through embodiments of the invention, but the invention according to the claims is not limited to the following embodiments. Furthermore, not all of the configurations described in the embodiments are necessarily essential means for solving the problems. For clarity of explanation, the following description and drawings have been omitted and simplified as appropriate. In each drawing, the same elements are given the same reference numerals, and repeated explanations are omitted as necessary.

[0012] 1 is mounted on a vehicle. The driving assistance device 100 includes a two-wheeled vehicle detection unit 101, an oncoming vehicle detection unit 102, a collision determination unit 103, and an attention-calling unit 104.

[0013] The two-wheeled vehicle detection means 101 detects two-wheeled vehicles traveling in the host vehicle lane, which is the lane in which the host vehicle is traveling.

[0014] The oncoming vehicle detection means 102 detects an oncoming vehicle that has entered or is attempting to enter the host vehicle's lane from an oncoming lane.

[0015] The collision determination means 103 determines whether or not there is a possibility that an oncoming vehicle will collide with the two-wheeled vehicle.

[0016] The warning means 104 warns the driver of an oncoming vehicle to be careful when there is a possibility that the oncoming vehicle will collide with the motorcycle.

[0017] Figure 2 shows the operation flow of the driving assistance device 100. As shown in Figure 2, the motorcycle detection means 101 detects a motorcycle traveling in the host vehicle lane, which is the lane in which the host vehicle is traveling (S1000). Next, the oncoming vehicle detection means 102 detects an oncoming vehicle that has entered or is attempting to enter the host vehicle lane from the oncoming lane (S1001). Next, the collision determination means 103 determines whether or not there is a possibility that the oncoming vehicle will collide with the motorcycle (S1002). Next, the attention alert means 104 alerts the driver of the oncoming vehicle if there is a possibility that the oncoming vehicle will collide with the motorcycle (S1003).

[0018] According to the above configuration, it is possible to prevent a collision between the two-wheeled vehicle and another vehicle.

[0019] First Embodiment Next, a first embodiment of the present disclosure will be described.

[0020] Fig. 3 shows a plan view of intersection 1. As shown in Fig. 3, at intersection 1, for example, road 2 extending north-south and road 3 extending east-west intersect. For example, roads 2 and 3 are roads with one lane in each direction. However, instead of this, roads 2 and 3 may be roads with two lanes in each direction, or roads with three or more lanes in each direction.

[0021] Road 2 is made up of a southern lane 2s, which is defined as a southbound lane, and a northern lane 2n, which is defined as a northbound lane. Road 3 is made up of an eastern lane 3e, which is defined as an eastbound lane, and a western lane 3w, which is defined as a westbound lane.

[0022] For ease of explanation, it is assumed that four-wheeled vehicles 4a and 4b are traveling in the southbound lane 2s. The four-wheeled vehicles 4a and 4b are traveling south toward intersection 1. Furthermore, it is assumed that two-wheeled vehicles 5a, 5b, and 5c are traveling in the southbound lane 2s. The two-wheeled vehicles 5a and 5b are traveling south toward intersection 1. The two-wheeled vehicle 5c is traveling north toward intersection 1. In other words, the two-wheeled vehicle 5c is traveling in the wrong direction in the southbound lane 2s. As an example, the two-wheeled vehicles 5a and 5b are motorized two-wheeled vehicles, and the two-wheeled vehicle 5c is a bicycle without a motorized vehicle. However, this is not a limitation, and the two-wheeled vehicles 5a, 5b, and 5c may all be motorized two-wheeled vehicles, or the two-wheeled vehicles 5a, 5b, and 5c may all be bicycles without a motorized vehicle. Also, assume that four-wheeled vehicle 4c, which has been traveling in the northern lane 2n, is stopped within intersection 1 in order to make a right turn at intersection 1. That is, it can be said that four-wheeled vehicle 4c is attempting to enter from the northern lane 2n to the southern lane 2s at intersection 1. The purpose of attempting to enter from the northern lane 2n to the southern lane 2s is not limited to the purpose of four-wheeled vehicle 4c making a right turn at intersection 1 as illustrated, but may also be, for example, four-wheeled vehicle 4c turning around at intersection 1 and traveling south on the southern lane 2s, or four-wheeled vehicle 4c crossing the southern lane 2s at a location other than intersection 1 to enter a facility along the southern lane 2s.

[0023] The southern lane 2s is a specific example of the host vehicle's lane. The northern lane 2n is a specific example of an oncoming lane. The four-wheeled vehicles 4a and 4b are specific examples of the host vehicle. The four-wheeled vehicle 4c is a specific example of an oncoming vehicle.

[0024] The four-wheeled vehicle 4a is closer to the intersection 1 than the four-wheeled vehicle 4b. Therefore, the four-wheeled vehicle 4a corresponds to a preceding vehicle from the perspective of the four-wheeled vehicle 4b. As an example, the two-wheeled vehicle 5a is traveling beside the four-wheeled vehicle 4a in the same direction as the traveling direction of the four-wheeled vehicle 4a. In other words, the two-wheeled vehicle 5a is traveling parallel to the four-wheeled vehicle 4a. The two-wheeled vehicle 5a is traveling in front of the four-wheeled vehicle 4b. The two-wheeled vehicle 5b is traveling behind the four-wheeled vehicle 4a in the same direction as the traveling direction of the four-wheeled vehicle 4a. The two-wheeled vehicle 5b is traveling behind the four-wheeled vehicle 4b. The two-wheeled vehicle 5c is traveling behind the four-wheeled vehicle 4c. The two-wheeled vehicle 5c is traveling so that the distance between the two-wheeled vehicle 5c and the four-wheeled vehicle 4a is shortened. In short, the two-wheeled vehicle 5c is traveling towards the four-wheeled vehicle 4a. At intersection 1, pedestrian 8 is about to cross road 3 heading north.

[0025] The driving assistance devices 6 mounted on the four-wheeled vehicles 4a and 4b alert the driver of the four-wheeled vehicle 4c to avoid a collision between the four-wheeled vehicle 4c and the two-wheeled vehicle 5a, 5b, or 5c, as will be described later. A driving assistance device 6 having the same configuration is also mounted on the four-wheeled vehicle 4c. Hereinafter, the four-wheeled vehicles 4a, 4b, and 4c will also be simply referred to as four-wheeled vehicles 4. Similarly, the two-wheeled vehicles 5a, 5b, and 5c will also be simply referred to as two-wheeled vehicles 5.

[0026] FIG. 4 shows a block diagram of the four-wheeled vehicle 4. As shown in FIG. 4, the four-wheeled vehicle 4 includes a driving assistance device 6, a front camera 7a, a side camera 7b, and a rear camera 7c. The front camera 7a captures images of the area in front of the four-wheeled vehicle 4 at predetermined intervals and outputs the captured images to the driving assistance device 6. The side camera 7b captures images of the area to the sides of the four-wheeled vehicle 4 at predetermined intervals and outputs the captured images to the driving assistance device 6. The rear camera 7c captures images of the area behind the four-wheeled vehicle 4 at predetermined intervals and outputs the captured images to the driving assistance device 6. Instead of including the front camera 7a, the side camera 7b, and the rear camera 7c, the four-wheeled vehicle 4 may be provided with an omnidirectional camera capable of capturing images in all directions. In this case, the omnidirectional camera captures images in all directions at predetermined intervals and outputs the captured images to the driving assistance device 6. A vehicle speed signal is input to the driving assistance device 6 from an ECU (Electronic Control Unit) (not shown) of the four-wheeled vehicle 4.

[0027] The driving assistance device 6 includes a processor 6a, a memory 6b, and a communication interface 6c. The processor 6a communicates with the driving assistance devices 6 of other four-wheeled vehicles 4 via the communication interface 6c. Communication between four-wheeled vehicles 4 using the communication interface 6c may be achieved via a wide area network (WAN) such as the Internet, or may be achieved without a WAN such as the Internet. When a WAN is not used, communication between four-wheeled vehicles 4 using the communication interface 6c may typically be achieved by vehicle-to-vehicle communication such as C-V2X (Cellular-Vehicle to Everything) or short-range wireless communication such as Wi-Fi. The memory 6b is realized by a read-only memory (ROM), a random access memory (RAM), a hard disk drive (HDD), or a solid state drive (SSD). The processor 6a reads and executes programs stored in the memory 6b. As a result, the programs cause hardware such as the processor 6a to function as a motorcycle detection unit 10, an oncoming vehicle detection unit 11, a collision determination unit 12, and an attention alert unit 13.

[0028] The driving assistance device 6 mounted on the four-wheeled vehicle 4a, the driving assistance device 6 mounted on the four-wheeled vehicle 4b, and the driving assistance device 6 mounted on the four-wheeled vehicle 4c all have the same configuration. When describing the driving assistance device 6 below, for the sake of convenience, the description will sometimes be given by specifying which four-wheeled vehicle 4 the driving assistance device 6 is mounted on, and sometimes without specifying which four-wheeled vehicle 4 the driving assistance device 6 is mounted on. The four-wheeled vehicle 4 may also be referred to as the host vehicle 4.

[0029] The motorcycle detection unit 10 detects motorcycles 5 traveling around the host vehicle 4 based on captured images output from the front camera 7a, the side camera 7b, and the rear camera 7c. Specifically, the motorcycle detection unit 10 detects motorcycles 5 traveling around the host vehicle 4 by inputting the captured images into an object detector such as R-CNN, YOLO (You Only Look Once), or SSD (Single Shot MultiBox Detector).

[0030] As an example, the motorcycle detection unit 10 of the four-wheeled vehicle 4a detects the motorcycle 5c using the captured image output from the front camera 7a, detects the motorcycle 5a using the captured image output from the side camera 7b, and detects the motorcycle 5b using the captured image output from the rear camera 7c. The motorcycle detection unit 10 of the four-wheeled vehicle 4b detects the motorcycle 5a using the captured image output from the front camera 7a, and detects the motorcycle 5b using the captured image output from the rear camera 7c.

[0031] The motorcycle detection unit 10 detects the relative position, traveling speed, and traveling direction of the motorcycle 5 with respect to the host vehicle 4 based on the captured images output from the front camera 7a, etc. The motorcycle detection unit 10 may use a known algorithm when detecting the relative position, traveling speed, and traveling direction of the motorcycle 5 with respect to the host vehicle 4 based on the captured images output from the front camera 7a, etc. For example, the motorcycle detection unit 10 may detect the relative position of the motorcycle 5 with respect to the host vehicle 4 based on the detected position of the motorcycle 5 in the captured images. Furthermore, for example, the motorcycle detection unit 10 may detect the traveling direction and traveling speed of the motorcycle 5 based on the detected position of the motorcycle 5 in each of multiple captured images output from the same camera and a vehicle speed signal of the host vehicle 4. Note that the four-wheeled vehicle 4 may be equipped with a RADAR (Radio detection and ranging) or a LiDAR (Light detection and ranging) instead of the front camera 7a, etc. In this case, the motorcycle detection unit 10 can reconstruct a three-dimensional space from the point cloud output from the RADAR or LiDAR using SLAM (Simultaneous Localization and Mapping) technology, and detect the motorcycle 5 traveling around the host vehicle 4 based on the three-dimensional space. The motorcycle detection unit 10 may also detect the motorcycle 5 based on the difference between multiple captured images.

[0032] The oncoming vehicle detection unit 11 detects a four-wheeled vehicle 4c as an oncoming vehicle around the host vehicle 4 based on the captured image output from the front camera 7a. Specifically, the oncoming vehicle detection unit 11 of the four-wheeled vehicle 4a detects the four-wheeled vehicle 4c by inputting the captured image to the object detector described above. The oncoming vehicle detection unit 11 also detects the relative position of the four-wheeled vehicle 4c with respect to the host vehicle 4, as well as the traveling speed and traveling direction. The oncoming vehicle detection unit 11 also detects the blinking behavior of the turn signal of the four-wheeled vehicle 4c based on the captured image output from the front camera 7a. Note that the four-wheeled vehicle 4 may be equipped with a RADAR or LiDAR instead of the front camera 7a, etc., and may reconstruct a three-dimensional space using SLAM technology from the point cloud output from the RADAR or LiDAR, and detect the four-wheeled vehicle 4c as an oncoming vehicle around the host vehicle 4 based on the three-dimensional space. The oncoming vehicle detection unit 11 may acquire blinking information indicating the blinking operation of the direction indicator of the four-wheeled vehicle 4c from the four-wheeled vehicle 4c via the communication interface 6c.

[0033] The collision determination unit 12 determines whether or not there is a possibility that the four-wheeled vehicle 4 c will collide with the two-wheeled vehicle 5 based on the detection results from the two-wheeled vehicle detection unit 10 and the oncoming vehicle detection unit 11 .

[0034] For example, if the oncoming vehicle detection unit 11 detects the four-wheeled vehicle 4c and the two-wheeled vehicle detection unit 10 detects at least one of the two-wheeled vehicles 5a, 5b, and 5c, the collision judgment unit 12 of the four-wheeled vehicle 4a determines that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5 that has already been detected.

[0035] Specifically, when the collision determination unit 12 of the four-wheeled vehicle 4a detects the four-wheeled vehicle 4c and the two-wheeled vehicle 5a, it may determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5a. In this case, the collision determination unit 12 of the four-wheeled vehicle 4a may detect the four-wheeled vehicle 4c and the two-wheeled vehicle 5a and determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5a when the difference between the traveling speed of the four-wheeled vehicle 4a and the traveling speed of the two-wheeled vehicle 5a is greater than a predetermined value. Specifically, when the traveling speed of the four-wheeled vehicle 4a is higher than the traveling speed of the two-wheeled vehicle 5a by at least the predetermined value, there is a possibility that the two-wheeled vehicle 5a will still be traveling within the intersection 1 when the four-wheeled vehicle 4a passes through the intersection 1. Therefore, if the four-wheeled vehicle 4c makes a right turn at the intersection 1 immediately after the four-wheeled vehicle 4a passes through the intersection 1, there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5a.

[0036] Furthermore, when the collision determination unit 12 of the four-wheeled vehicle 4a detects the four-wheeled vehicle 4c and the two-wheeled vehicle 5b, it may determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5b. In this case, there is a possibility that the two-wheeled vehicle 5b will still be traveling within the intersection 1 when the four-wheeled vehicle 4a passes through the intersection 1. Therefore, if the four-wheeled vehicle 4c turns right at the intersection 1 immediately after the four-wheeled vehicle 4a passes through the intersection 1, there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5b.

[0037] Furthermore, when the collision determination unit 12 of the four-wheeled vehicle 4a detects the four-wheeled vehicle 4c and the two-wheeled vehicle 5c, it may determine that the four-wheeled vehicle 4c is likely to collide with the two-wheeled vehicle 5c. In this case, the collision determination unit 12 of the four-wheeled vehicle 4a may determine that the four-wheeled vehicle 4c is likely to collide with the two-wheeled vehicle 5c if the distance between the four-wheeled vehicle 4c and the two-wheeled vehicle 5c is decreasing. Specifically, the driver of the four-wheeled vehicle 4c is particularly gazing northward, waiting for a break in the convoy consisting of the four-wheeled vehicles 4a and 4b. Furthermore, it is difficult for the driver of the four-wheeled vehicle 4c to predict the presence of the two-wheeled vehicle 5c traveling the wrong way in the southbound lane 2s. For this reason, the driver of the four-wheeled vehicle 4c may overlook the presence of the two-wheeled vehicle 5c traveling behind the four-wheeled vehicle 4c. Therefore, if four-wheeled vehicle 4c turns right at intersection 1, whether before or after four-wheeled vehicle 4a has passed through intersection 1, there is a possibility that four-wheeled vehicle 4c will collide with two-wheeled vehicle 5c.

[0038] Furthermore, when the collision determination unit 12 of the four-wheeled vehicle 4b detects the four-wheeled vehicle 4c and the two-wheeled vehicle 5b, it may determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5b. In this case, there is a possibility that the two-wheeled vehicle 5b will still be traveling within the intersection 1 when the four-wheeled vehicle 4b passes through the intersection 1. Therefore, if the four-wheeled vehicle 4c makes a right turn at the intersection 1 immediately after the four-wheeled vehicle 4b passes through the intersection 1, there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5b.

[0039] Furthermore, when the collision determination unit 12 of the four-wheeled vehicle 4b detects the four-wheeled vehicle 4c and the two-wheeled vehicle 5b and the traveling speed of the two-wheeled vehicle 5b is higher than the traveling speed of the four-wheeled vehicle 4b, the collision determination unit 12 of the four-wheeled vehicle 4b may determine that the four-wheeled vehicle 4c may collide with the two-wheeled vehicle 5b. In this case, it is possible that the two-wheeled vehicle 5b will overtake the four-wheeled vehicle 4b from the left side of the four-wheeled vehicle 4b. Therefore, if the four-wheeled vehicle 4c turns right at the intersection 1 immediately after the four-wheeled vehicle 4a passes the intersection 1, there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5b.

[0040] The warning unit 13 warns the driver of the four-wheeled vehicle 4c when there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5. Specifically, when traffic at the intersection 1 is controlled by a traffic light 20, the warning unit 13 determines the light color of the traffic light 20 and changes the intensity of the warning based on the determination result.

[0041] 3 , if the traffic lights 20 controlling traffic at the intersection 1 include a traffic light 20n controlling traffic of four-wheeled vehicles 4 and two-wheeled vehicles 5 that reach the intersection 1 by traveling in the northbound lane 2n, and a traffic light 20s controlling traffic of four-wheeled vehicles 4 and two-wheeled vehicles 5 that reach the intersection 1 by traveling in the southbound lane 2s, the attention warning unit 13 determines the light color of the traffic light 20n that controls traffic of the four-wheeled vehicle 4c at the intersection 1. The attention warning unit 13 of the four-wheeled vehicle 4a may estimate the light color of the traffic light 20n by determining the light color of the traffic light 20s based on the captured image output from the front camera 7a, assuming that the light colors of the traffic lights 20s and the traffic lights 20n are linked. Alternatively, the attention warning unit 13 of the four-wheeled vehicle 4a may receive light color information indicating the light color of the traffic light 20n from the four-wheeled vehicle 4c via the communication interface 6c and determine the light color of the traffic light 20n based on the light color information.Alternatively, the attention warning unit 13 of the four-wheeled vehicle 4a may receive light color information indicating the light color of the traffic light 20n from the traffic light 20n via the communication interface 6c and determine the light color of the traffic light 20n based on the light color information.

[0042] The attention warning unit 13 issues a low-level (first attention warning level) attention warning to the driver of the four-wheeled vehicle 4c when the light color of the traffic light 20n controlling traffic at the intersection 1 for the four-wheeled vehicle 4c is green. On the other hand, the attention warning unit 13 issues a high-level (second attention warning level) attention warning to the driver of the four-wheeled vehicle 4c when the light color of the traffic light 20n controlling traffic at the intersection 1 for the four-wheeled vehicle 4c is red or yellow. Here, the low-level attention warning is weaker than the high-level attention warning.

[0043] Various methods may be employed for the attention alert unit 13 to alert the driver of the four-wheeled vehicle 4c. For example, the attention alert unit 13 may alert the driver of the four-wheeled vehicle 4c by flashing the hazard lights of the host vehicle 4 in a predetermined flashing pattern. In this case, a low-level attention alert typically involves flashing the hazard lights five times per second, and a high-level attention alert typically involves flashing the hazard lights twice per second. Furthermore, for example, the attention alert unit 13 may transmit an attention alert signal to the four-wheeled vehicle 4c via the communication interface 6c. In this case, the driving assistance device 6 of the four-wheeled vehicle 4c alerts the driver of the four-wheeled vehicle 4c, typically by audio, based on the attention alert signal received from the host vehicle 4. Furthermore, for example, the attention alert unit 13 may alert the driver of the four-wheeled vehicle 4c by causing a warning sound to be output from a horn of the host vehicle 4. In this case, a low level of warning typically means that the sound pressure of the warning sound is 90 decibels, and a high level of warning typically means that the sound pressure of the warning sound is 110 decibels.

[0044] In this way, by changing the intensity of the warning depending on the light color of the traffic light 20n, it is possible to warn the driver of the four-wheeled vehicle 4c at an appropriate intensity. For example, when the light color of the traffic light 20n is green, the driver of the four-wheeled vehicle 4c is relaxed and can visually check whether a two-wheeled vehicle 5 is traveling in the southbound lane 2s. Therefore, in this case, a high level of warning is unnecessary and a low level of warning is sufficient. However, when the light color of the traffic light 20n is red or yellow, the driver of the four-wheeled vehicle 4c is relaxed and may neglect to visually check whether a two-wheeled vehicle 5 is traveling in the southbound lane 2s, and a high level of warning is therefore necessary.

[0045] Next, the operation of the driving support device 6 will be described with reference to FIG.

[0046] First, the driving assistance device 6 acquires an image captured by the front camera 7a or the like (S100). Next, the driving assistance device 6 acquires a vehicle speed signal from the ECU of the four-wheeled vehicle 4a (S110). Next, the motorcycle detection unit 10 of the driving assistance device 6 detects the motorcycle 5 traveling in the southbound lane 2s in which the host vehicle 4 is traveling (S120). Next, the oncoming vehicle detection unit 11 of the driving assistance device 6 detects the four-wheeled vehicle 4c attempting to enter the southbound lane 2s from the northbound lane 2n (S130). Next, the collision determination unit 12 of the driving assistance device 6 determines whether or not the four-wheeled vehicle 4c is likely to collide with the motorcycle 5 based on the detection results of the motorcycle detection unit 10 and the oncoming vehicle detection unit 11 (S140). If it is determined that the four-wheeled vehicle 4c is likely to collide with the motorcycle 5 (S150: YES), the collision determination unit 12 proceeds to step S160. On the other hand, when it is determined that there is no possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5 (S150: NO), the collision determination unit 12 returns the processing to step S100.

[0047] In step S160, the attention warning unit 13 determines the light color of the traffic light 20n that controls traffic at the intersection 1 for the four-wheeled vehicle 4c (S160). If the light color of the traffic light 20n is green (S170: green), the attention warning unit 13 issues a low-level attention warning to the driver of the four-wheeled vehicle 4c (S190) and returns the process to step S100. On the other hand, if the light color of the traffic light 20n is red or yellow (S170: red / yellow), the attention warning unit 13 issues a high-level attention warning to the driver of the four-wheeled vehicle 4c (S180) and returns the process to step S100.

[0048] The first embodiment of the present disclosure has been described above, and the above embodiment has the following features.

[0049] That is, the driving assistance device 6 is mounted on the host vehicle 4. The driving assistance device 6 includes a motorcycle detection unit 10 (motorcycle detection means) that detects a motorcycle 5 traveling in the southbound lane 2s (host vehicle lane), which is the lane in which the host vehicle 4 is traveling. The driving assistance device 6 includes an oncoming vehicle detection unit 11 (oncoming vehicle detection means) that detects a four-wheeled vehicle 4c (oncoming vehicle) attempting to enter the southbound lane 2s from the northbound lane 2n (oncoming lane). The driving assistance device 6 includes a collision determination unit 12 (collision determination means) that determines whether or not there is a possibility that the four-wheeled vehicle 4c will collide with the motorcycle 5. The driving assistance device 6 also includes an attention alert unit 13 (attention alert means) that alerts the driver of the four-wheeled vehicle 4c when there is a possibility that the four-wheeled vehicle 4c will collide with the motorcycle 5. The above configuration makes it possible to prevent a collision between a motorcycle and another vehicle. Specifically, it is possible to avoid a collision between the two-wheeled vehicle 5 and the four-wheeled vehicle 4c traveling in the southbound lane 2s in which the host vehicle 4 is traveling.

[0050] Furthermore, when the two-wheeled vehicle 5 is traveling in the same direction as the host vehicle 4, the collision determination unit 12 may determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5 when the two-wheeled vehicle 5 is traveling parallel to the host vehicle 4 or when the two-wheeled vehicle 5 is traveling behind the host vehicle 4. In Fig. 3, the two-wheeled vehicle 5a is traveling parallel to the four-wheeled vehicle 4a, the two-wheeled vehicle 5b is traveling behind the four-wheeled vehicle 4a, and the two-wheeled vehicle 5b is traveling behind the four-wheeled vehicle 4b.

[0051] Furthermore, if the difference between the traveling speed of the two-wheeled vehicle 5 and the traveling speed of the host vehicle 4 is greater than a predetermined value, the collision determination unit 12 may determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5. This is because, if there is a speed difference between the two-wheeled vehicle 5 and the host vehicle 4, there is a possibility that the two-wheeled vehicle 5 will overtake the host vehicle 4 or that the two-wheeled vehicle 5 will still be left behind at the intersection 1 when the host vehicle 4 passes through the intersection 1.

[0052] Furthermore, when the two-wheeled vehicle 5c is traveling in the wrong direction on the southbound lane 2s, the collision determination unit 12 may determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5c. This is because it is generally difficult to anticipate the presence of a vehicle traveling in the wrong direction, and therefore it is difficult for the driver of the four-wheeled vehicle 4c to recognize the presence of the two-wheeled vehicle 5c.

[0053] Furthermore, the collision determination unit 12 may determine that there is a possibility that the four-wheeled vehicle 4c will collide with the two-wheeled vehicle 5c when the two-wheeled vehicle 5c is traveling in the wrong direction in the southern lane 2s and the distance between the two-wheeled vehicle 5c and the host vehicle 4 is shortening. That is, when the distance between the two-wheeled vehicle 5c and the host vehicle 4 is shortening, the two-wheeled vehicle 5c will soon enter or leave a blind spot of the host vehicle 4 as viewed from the four-wheeled vehicle 4c, making it difficult for the driver of the four-wheeled vehicle 4c to recognize the presence of the two-wheeled vehicle 5c.

[0054] Furthermore, when the four-wheeled vehicle 4c is attempting to enter the southward lane 2s from the northward lane 2n at the intersection 1 and traffic at the intersection 1 for the four-wheeled vehicle 4c is controlled by the traffic light 20n, the attention alert unit 13 may alert the driver of the four-wheeled vehicle 4c in accordance with the light color of the traffic light 20n. This allows for the attention alert to be given in accordance with the light color of the traffic light 20n.

[0055] Furthermore, the attention warning unit 13 issues a low level (first attention warning level) to the driver of the four-wheeled vehicle 4c when the light color of the traffic light 20n is blue, and issues a high level (second attention warning level) to the driver of the four-wheeled vehicle 4c when the light color of the traffic light 20n is red or yellow. In this way, by changing the intensity of the attention warning depending on the light color of the traffic light 20n, it is possible to prevent the driver of the four-wheeled vehicle 4c from being excessively or insufficiently warned.

[0056] Furthermore, the southern lane 2s (the vehicle's lane) and the northern lane 2n (the oncoming lane) form a one-lane road. With the above configuration, the two-wheeled vehicle 5 traveling in the southern lane 2s is particularly difficult for the four-wheeled vehicle 4c to recognize, so the warning issued by the warning unit 13 is particularly useful.

[0057] Furthermore, the two-wheeled vehicle detection unit 10 detects the relative position and traveling speed of the two-wheeled vehicle 5 with respect to the host vehicle 4. With the above configuration, the accuracy of the determination by the collision determination unit 12 can be improved.

[0058] In the above example, the program can be stored and supplied to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Non-transitory computer-readable media include, for example, magnetic recording media, magneto-optical recording media, CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, and semiconductor memories. Semiconductor memories include, for example, mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs (Random Access Memory). The program may also be supplied to a computer by various types of transient computer-readable media. Examples of transient computer-readable media include electrical signals, optical signals, and electromagnetic waves. The transient computer-readable media can be supplied to a computer via wired communication paths such as electrical wires and optical fibers, or wireless communication paths.

[0059] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure.

[0060] For example, if a pedestrian signal is provided at the intersection 1, the attention alert unit 13 may not alert the driver of the four-wheeled vehicle 4c if the pedestrian signal located in front of the driver of the two-wheeled vehicle 5c has a red light. This is because if the pedestrian signal located in front of the driver of the two-wheeled vehicle 5c has a red light, the two-wheeled vehicle 5c is likely to stop without entering the intersection 1.

[0061] The collision determination unit 12 may also determine whether or not there is a possibility that the four-wheeled vehicle 4 c will collide with the pedestrian 8. In this case, the collision determination unit 12 of the driving assistance device 6 can detect the pedestrian 8, as well as the position, walking direction, and walking speed of the pedestrian 8, by inputting a plurality of captured images output from the front camera 7 a to an object detector.

[0062] In the above embodiment, the oncoming vehicle detection unit 11 detects a four-wheeled vehicle 4c (oncoming vehicle) attempting to enter the southern lane 2s from the northern lane 2n (oncoming lane). However, in addition to this, the oncoming vehicle detection unit 11 may also detect a four-wheeled vehicle 4c (oncoming vehicle) that has entered the southern lane 2s from the northern lane 2n (oncoming lane). That is, the oncoming vehicle detection unit 11 may detect a four-wheeled vehicle 4c (oncoming vehicle) that has entered or is attempting to enter the southern lane 2s from the northern lane 2n (oncoming lane).

[0063] Each drawing is merely an example for describing one or more embodiments. Each drawing may not relate to only one particular embodiment, but may also relate to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0064] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes.

[0065] (Supplementary Note 1) A driving assistance device mounted on a host vehicle, comprising: two-wheeled vehicle detection means for detecting a two-wheeled vehicle traveling in a host vehicle lane that is the lane in which the host vehicle is traveling; oncoming vehicle detection means for detecting an oncoming vehicle entering or attempting to enter the host vehicle lane from an oncoming lane; collision determination means for determining whether the oncoming vehicle is likely to collide with the two-wheeled vehicle; and attention calling means for calling the driver of the oncoming vehicle's attention if there is a possibility of the oncoming vehicle colliding with the two-wheeled vehicle. (Supplementary Note 2) The driving assistance device according to Supplementary Note 1, wherein, when the two-wheeled vehicle is traveling in the same direction as the host vehicle, the collision determination means determines that there is a possibility of the oncoming vehicle colliding with the two-wheeled vehicle if the two-wheeled vehicle is traveling parallel to the host vehicle or traveling behind the host vehicle. (Supplementary Note 3) The driving assistance device according to Supplementary Note 2, wherein the collision determination means determines that there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle when a difference between the traveling speed of the two-wheeled vehicle and the traveling speed of the host vehicle is greater than a predetermined value. (Supplementary Note 4) The driving assistance device according to Supplementary Note 1, wherein the collision determination means determines that there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle when the two-wheeled vehicle is traveling in the wrong direction in the host vehicle's lane. (Supplementary Note 5) The driving assistance device according to Supplementary Note 4, wherein the collision determination means determines that there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle when the two-wheeled vehicle is traveling in the wrong direction in the host vehicle's lane and the distance between the two-wheeled vehicle and the host vehicle is decreasing. (Supplementary Note 6) The driving assistance device according to Supplementary Note 1, wherein when the oncoming vehicle is entering or attempting to enter the host vehicle lane from the oncoming lane at an intersection and traffic at the intersection for the oncoming vehicle is controlled by a traffic light, the attention warning means warns the driver of the oncoming vehicle in accordance with a light color of the traffic light.(Supplementary Note 7) The driving assistance device according to Supplementary Note 6, wherein the attention warning means warns the driver of the oncoming vehicle at a first attention warning level when the traffic light is blue, and warns the driver of the oncoming vehicle at a second attention warning level higher than the first attention warning level when the traffic light is red or yellow. (Supplementary Note 8) The driving assistance device according to Supplementary Note 1, wherein the host vehicle lane and the oncoming vehicle lane form a one-lane road. (Supplementary Note 9) The driving assistance device according to Supplementary Note 1, wherein the two-wheeled vehicle detection means detects the position and traveling speed of the two-wheeled vehicle relative to the host vehicle. (Supplementary Note 10) A driving assistance method in which a driving assistance device mounted on a host vehicle detects a two-wheeled vehicle traveling in a host vehicle lane in which the host vehicle is traveling, detects an oncoming vehicle that enters or attempts to enter the host vehicle lane from an oncoming lane, determines whether or not there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle, and if there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle, issues a warning to the driver of the oncoming vehicle. (Supplementary Note 11) A program that causes a driving assistance device mounted on a host vehicle to function as: two-wheeled vehicle detection means that detects a two-wheeled vehicle traveling in the host vehicle lane in which the host vehicle is traveling, oncoming vehicle detection means that detects an oncoming vehicle that enters or attempts to enter the host vehicle lane from an oncoming lane, collision determination means that determine whether or not there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle, and attention alert means that issues a warning to the driver of the oncoming vehicle if there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle.

[0066] Some or all of the elements (e.g., configurations and functions) described in Supplementary Notes 2 to 9 that are dependent on Supplementary Notes 1 may also be dependent on Supplementary Notes 10 to 11 in the same dependency relationship as Supplementary Notes 2 to 9. Some or all of the elements described in any Supplementary Note may be applied to various hardware, software, recording means for recording software, systems, and methods.

[0067] The present disclosure is applicable to technology for preventing collisions between motorcycles and other vehicles.

[0068] REFERENCE SIGNS LIST 1 Intersection 2 Road 2s Southbound lane 2n Northbound lane 3 Road 3e Eastbound lane 3w Westbound lane 4 Four-wheeled vehicle 4 Vehicle 4a Four-wheeled vehicle 4b Four-wheeled vehicle 4c Four-wheeled vehicle 5 Two-wheeled vehicle 5a Two-wheeled vehicle 5b Two-wheeled vehicle 5c Two-wheeled vehicle 6 Driving assistance device 6a Processor 6b Memory 6c Communication interface 7a Front camera 7b Side camera 7c Rear camera 8 Pedestrian 10 Two-wheeled vehicle detection unit 11 Oncoming vehicle detection unit 12 Collision determination unit 13 Attention warning unit 20 Traffic light 20n Traffic light 20s Traffic light

Claims

1. A driving assistance device mounted on a host vehicle, comprising: two-wheeled vehicle detection means for detecting a two-wheeled vehicle traveling in the host vehicle lane in which the host vehicle is traveling; oncoming vehicle detection means for detecting an oncoming vehicle that has entered or is attempting to enter the host vehicle lane from an oncoming lane; collision determination means for determining whether or not the oncoming vehicle is likely to collide with the two-wheeled vehicle; and attention alert means for alerting the driver of the oncoming vehicle when there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle.

2. A driving assistance device as described in claim 1, wherein, when the two-wheeled vehicle is traveling in the same direction as the host vehicle, the collision determination means determines that there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle when the two-wheeled vehicle is traveling parallel to the host vehicle or when the two-wheeled vehicle is traveling behind the host vehicle.

3. A driving assistance device according to claim 2, wherein the collision determination means determines that there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle when the difference between the traveling speed of the two-wheeled vehicle and the traveling speed of the host vehicle is greater than a predetermined value.

4. A driving assistance device according to claim 1, wherein, when the two-wheeled vehicle is traveling in the wrong direction in the vehicle's own lane, the collision determination means determines that there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle.

5. A driving assistance device as described in claim 4, wherein the collision determination means determines that there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle when the two-wheeled vehicle is traveling in the wrong direction in the vehicle's lane and the distance between the two-wheeled vehicle and the vehicle is decreasing.

6. A driving assistance device as claimed in claim 1, wherein, when the oncoming vehicle is entering or attempting to enter the vehicle's lane from the oncoming lane at an intersection and traffic at the intersection for the oncoming vehicle is controlled by a traffic signal, the attention warning means warns the driver of the oncoming vehicle in accordance with the color of the traffic signal.

7. A driving assistance device as described in claim 6, wherein the attention warning means warns the driver of the oncoming vehicle at a first attention warning level when the traffic light is blue, and warns the driver of the oncoming vehicle at a second attention warning level higher than the first attention warning level when the traffic light is red or yellow.

8. A driving assistance device according to claim 1, wherein the vehicle lane and the oncoming lane form a one-lane road.

9. A driving assistance device according to claim 1, wherein the two-wheeled vehicle detection means detects the relative position and traveling speed of the two-wheeled vehicle with respect to the host vehicle.

10. A driving assistance method in which a driving assistance device mounted on a host vehicle detects a two-wheeled vehicle traveling in the host vehicle's lane, which is the lane in which the host vehicle is traveling, detects an oncoming vehicle entering or attempting to enter the host vehicle's lane from an oncoming lane, determines whether or not the oncoming vehicle is likely to collide with the two-wheeled vehicle, and if there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle, issues a warning to the driver of the oncoming vehicle.

11. A program that causes a driving assistance device mounted on a host vehicle to function as: two-wheeled vehicle detection means that detects two-wheeled vehicles traveling in the host vehicle's lane, which is the lane in which the host vehicle is traveling; oncoming vehicle detection means that detects oncoming vehicles that have entered or are attempting to enter the host vehicle's lane from an oncoming lane; collision determination means that determines whether the oncoming vehicle is likely to collide with the two-wheeled vehicle; and warning means that warns the driver of the oncoming vehicle if there is a possibility that the oncoming vehicle will collide with the two-wheeled vehicle.

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