Vehicle detection device, vehicle detection method, and vehicle detection program

Abstract

To provide a technique for improving safety in changing a lane after passing.SOLUTION: An exemplary vehicle detection device performs: detecting another vehicle present on an adjacent lane in front of a self vehicle; determining whether the other vehicle is a passing object vehicle based on at least one of a relative position and a relative speed between the self vehicle and the other vehicle; identifying the passing object vehicle based on vehicle information acquired from an outside-vehicle sensor; and tracking the passing object vehicle until an inter-vehicle distance between the identified passing object vehicle and the self vehicle exceeds a threshold.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a vehicle detection device, a vehicle detection method, and a vehicle detection program. [Background technology]

[0002] When a vehicle changes lanes ahead of another vehicle, it is important to maintain a sufficient distance from the other vehicle in order to prevent accidents. For example, there is a known method of informing the driver that a predetermined distance has been maintained between the vehicles (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-341698 Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, devices have become known that use sensors to detect objects around a vehicle and alert the driver. However, depending on the sensor's detection range, the detection of other vehicles after overtaking may be insufficient. Even if the distance between the vehicles is sufficient for the vehicle to change lanes after overtaking, if the distance between the vehicles is relatively small, the driver of the other vehicle may perceive the other vehicle as suddenly cutting in. In particular, vehicle movements involving lane changes after overtaking could lead to near misses and other vehicle tailgating. On the other hand, if the detection range of a sensor that detects objects around a vehicle is always expanded to a sufficient distance between the vehicles that allows for lane changes, there is a problem that unnecessary vehicles and obstacles may be detected, resulting in unnecessary warnings.

[0005] In view of the above circumstances, an object of the present invention is to provide a technique that can improve safety when changing lanes after overtaking. [Means for solving the problem]

[0006] An exemplary vehicle detection device of the present invention detects other vehicles in an adjacent lane ahead of the vehicle, determines whether the other vehicle is a vehicle to be overtaken based on at least one of the relative position and relative speed between the vehicle and the other vehicle, identifies the vehicle to be overtaken based on vehicle information obtained from an external sensor, and tracks the vehicle to be overtaken until the inter-vehicle distance between the identified vehicle to be overtaken and the vehicle exceeds a threshold value. [Effects of the Invention]

[0007] According to the exemplary embodiment of the present invention, after the host vehicle has overtaken the target vehicle, the host vehicle tracks the target vehicle until the inter-vehicle distance between the host vehicle and the target vehicle exceeds a threshold value, so that the host vehicle can track the target vehicle until a sufficient inter-vehicle distance (inter-vehicle distance exceeding the threshold value) is secured. This tracking can improve safety when changing lanes after overtaking. [Brief explanation of the drawings]

[0008] [Figure 1] Diagram showing adjacent areas of a lane change decision support system [Figure 2] Diagram showing the rear area of ​​the lane change decision support system [Figure 3] FIG. 1 is a diagram illustrating an example of a schematic configuration of a vehicle according to an exemplary embodiment of the present invention. [Figure 4] Diagram showing an example of the configuration of a vehicle detection ECU [Figure 5] FIG. 1 shows an example of a handover area. [Figure 6] 1 is a flowchart showing a first example of a vehicle detection process executed by a vehicle detection ECU; [Figure 7A] A bird's-eye view showing the relative positions of your vehicle and other vehicles [Figure 7B] A bird's-eye view showing the relative positions of your vehicle and other vehicles [Figure 7C] A bird's-eye view showing the relative positions of your vehicle and other vehicles [Figure 7D] A bird's-eye view showing the relative positions of your vehicle and other vehicles [Figure 7E]A bird's-eye view showing the relative positions of your vehicle and other vehicles [Figure 7F] A bird's-eye view showing the relative positions of your vehicle and other vehicles [Figure 8] 10 is a flowchart showing a second example of a vehicle detection process executed by the vehicle detection ECU. [Figure 9] 10 is a flowchart showing a third example of a vehicle detection process executed by a vehicle detection ECU. [Figure 10] 10 is a flowchart showing a fourth example of a vehicle detection process executed by a vehicle detection ECU. [Figure 11] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. [Figure 12] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. [Figure 13] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. [Figure 14] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. [Figure 15] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. [Figure 16] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. [Figure 17] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. [Figure 18] FIG. 10 is a diagram showing an example of a display screen displayed on a display device. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Comparative Example> First, before describing the exemplary embodiment of the present invention, first to third comparative examples will be described in order. In comparison with the first to third comparative examples, the advantageous effects of the exemplary embodiment of the present invention will become clear.

[0010] The vehicle detection device of the first comparative example is a device that complies with Lane Change Decision Aid Systems (LCDAS) defined in ISO 17387, and monitors a left adjacent area 102 and a right adjacent area 103 shown in Fig. 1. The vehicle detection device of the first comparative example detects other vehicles that are present in the left adjacent area 102 and the right adjacent area 103, which are blind spots for the driver of a host vehicle 101 traveling in a traveling direction D1.

[0011] The vehicle detection device of the second comparative example is a device that conforms to the lane change decision support system defined in ISO 17387, and monitors the left rear area 104 and the right rear area 105 shown in Fig. 2. The vehicle detection device of the second comparative example detects other vehicles that are present in the left rear area 104 and the right rear area 105 and approaching the host vehicle 101 (traveling at a faster speed than the host vehicle 101).

[0012] The vehicle detection device of the third comparative example is a device that conforms to the lane change decision support system defined in ISO 17387, and monitors the left adjacent area 102 and right adjacent area 103 shown in Fig. 1, and the left rear area 104 and right rear area 105 shown in Fig. 2. The vehicle detection device of the third comparative example detects other vehicles that are present in the left adjacent area 102 and right adjacent area 103, which are blind spots for the driver of the host vehicle 101 traveling in the traveling direction D1, and other vehicles that are present in the left rear area 104 and right rear area 105 and are approaching the host vehicle 101 (traveling faster than the host vehicle 101).

[0013] In the vehicle detection device of the first comparative example, when changing lanes after overtaking, depending on the detection range of the sensor, there are cases where it is not possible to detect other vehicles that are at a dangerous distance when changing lanes after overtaking. Also, even if the distance between the vehicles is sufficient for lane changing, if the distance between the vehicles when changing lanes is relatively small, the driver of the other vehicle may feel that the other vehicle is suddenly cutting in, which may result in near misses or problems such as tailgating by other vehicles.

[0014] Furthermore, with the vehicle detection device of the second comparative example, when changing lanes after overtaking, it may not be possible to detect other vehicles in the blind spot, and if the area for detecting other vehicles is expanded as with the vehicle detection device of the third comparative example, there is a problem in that vehicles and obstacles that do not need to be detected may also be detected, resulting in unnecessary warnings.

[0015] To address these issues, the exemplary vehicle detection device of the present invention is configured to determine whether a vehicle in an adjacent lane ahead of the vehicle is a target vehicle to be overtaken, and if it is determined that the vehicle is a target vehicle to be overtaken, to track the target vehicle until the inter-vehicle distance from the target vehicle exceeds a threshold. The exemplary vehicle detection device of the present invention can improve safety when changing lanes after overtaking while suppressing unnecessary warnings.

[0016] Exemplary embodiments of the present invention will now be described in detail.

[0017] <Vehicle configuration> 3 is a diagram showing a schematic configuration example of a vehicle V1 (hereinafter referred to as host vehicle V1) according to an exemplary embodiment of the present invention. Note that in FIG. 3, components necessary for explaining the features of this embodiment are shown, and descriptions of general components are omitted.

[0018] The host vehicle V1 includes an outside sensor 1, an inside sensor 2, a vehicle detection ECU (Electronic Control Unit) 3, and a notification device 4.

[0019] The external sensor 1 is a sensor for detecting other vehicles present around the host vehicle V1. The other vehicles are not limited to four-wheeled vehicles but also include two-wheeled vehicles, etc. The external sensor 1 is, for example, a millimeter-wave radar, an ultrasonic sensor, a LiDAR (Light Detection and Ranging), a camera that captures images of the surroundings of the host vehicle V1, etc. The external sensor 1 may be composed of one type of sensor or multiple types of sensors.

[0020] The interior sensor 2 is a sensor for detecting the state of the driver of the host vehicle V1. The state of the driver of the host vehicle V1 to be detected may be, for example, the line of sight direction of the driver of the host vehicle V1, the gestures of the driver of the host vehicle V1, the emotions of the driver of the host vehicle V1, etc. The interior sensor 2 may be, for example, a camera that captures an image of the driver of the host vehicle V1, a microphone that acquires voice data of the driver of the host vehicle V1, a biosensor that measures biosignals of the driver of the host vehicle V1, etc. The interior sensor 2 may be composed of one type of sensor or multiple types of sensors.

[0021] The vehicle detection ECU3 is a computer and is a vehicle detection device that tracks an overtaking target vehicle. The vehicle detection ECU3 may detect other vehicles present in each of the left adjacent area and the right adjacent area, similar to the vehicle detection device of the first comparative example described above. The vehicle detection ECU3 may also detect other vehicles present in each of the left adjacent area and the right adjacent area and approaching the host vehicle V1 (traveling faster than the host vehicle V1), similar to the vehicle detection device of the second comparative example described above. The vehicle detection ECU3 may also detect other vehicles present in each of the left adjacent area and the right adjacent area, and other vehicles present in each of the left adjacent area and the right adjacent area and approaching the host vehicle V1 (traveling faster than the host vehicle V1), similar to the vehicle detection device of the third comparative example described above.

[0022] The notification device 4 is an output device for issuing a notification regarding an overtaking target vehicle. The notification device 4 is, for example, a speaker, a vibration device, a display device, etc. The speakers are, for example, arranged in the right front door and the left front door of the host vehicle V1. The vibration device is, for example, built into the seat where the driver of the host vehicle V1 sits, the steering wheel, etc. The display device may be arranged in a position visible to the driver of the host vehicle V1, for example, on the dashboard or meter panel. The position of the notification device 4 is not limited to the above, and may be arranged in a position where it can notify the driver of the host vehicle V1. Furthermore, the notification device 4 may be used in combination with an existing in-vehicle device. Note that notification may be made by, for example, light, in addition to sound and vibration.

[0023] <Vehicle detection ECU configuration> Fig. 4 is a diagram showing an example of the configuration of the vehicle detection ECU 3. Note that Fig. 4 shows components necessary for explaining the features of this embodiment, and omits descriptions of general components.

[0024] The vehicle detection ECU 3 of the configuration example shown in FIG. 4 includes a communication unit 31, a storage unit 32, and a controller 33.

[0025] The communication unit 31 is an interface for communicating data with the vehicle exterior sensor 1, the vehicle interior sensor 2, and the notification device 4 shown in FIG. 3 via the vehicle interior network.

[0026] The storage unit 32 includes a volatile memory and a non-volatile memory. The volatile memory may include, for example, a random access memory (RAM). The non-volatile memory may include, for example, a read-only memory (ROM), a flash memory, or a hard disk drive. The non-volatile memory stores computer-readable programs and data.

[0027] The storage unit 32 stores a vehicle detection program 321, detection conditions 322 for detecting another vehicle in an adjacent lane ahead of the host vehicle V1, determination conditions 323 for determining whether the other vehicle in the adjacent lane ahead of the host vehicle V1 is a vehicle to be overtaken, and a threshold value 324 for determining a safe inter-vehicle distance for changing lanes after overtaking. For example, the threshold value 324 is a value indicating the boundary between a dangerous distance for changing lanes after overtaking and a safe inter-vehicle distance for changing lanes.

[0028] Furthermore, the threshold value 324 may be a value indicating the boundary between the danger distance for lane changes after overtaking and the safe following distance, plus a predetermined distance. In this case, lane changes can be made with a larger margin of safety in lane changes after overtaking, further improving safety in lane changes after overtaking. The threshold value 324 may be a fixed value, but is desirably variable depending on variable conditions such as the traveling speed of the host vehicle V1 and the relative speed between the host vehicle V1 and the vehicle to be overtaken. When the threshold value 324 is a variable value, the storage unit 32 stores a relational expression, a data table, or the like indicating the relationship between the threshold value 324 and the variable conditions.

[0029] The controller 33 includes a processor that performs arithmetic processing and the like. The processor may include, for example, a CPU (Central Processing Unit). The controller 33 may be configured with one processor or multiple processors. When configured with multiple processors, the processors may be connected to each other so that they can communicate with each other.

[0030] The controller 33 includes, as its functions, an acquisition unit 331, a vehicle detection unit 332, an overtaking target vehicle determination unit 333, an overtaking target vehicle monitoring unit 334, and an overtaking target vehicle notification unit 335. In this embodiment, the functions of the controller 33 are realized by the processor executing arithmetic processing in accordance with a vehicle detection program 321 stored in the memory unit 32.

[0031] The acquisition unit 331 acquires the output signal of the vehicle exterior sensor 1 and the output signal of the vehicle interior sensor 2 via the communication unit 31 .

[0032] The other vehicle detection unit 332 detects other vehicles in an adjacent lane ahead of the host vehicle V1 in accordance with the detection conditions 322 stored in the storage unit 32. The detection conditions 322 include the setting of a handover area, which is a certain range from the driver of the host vehicle V1. The handover area will be described with reference to FIG. 5. FIG. 5 is a diagram showing an example of a handover area 106 set for the host vehicle V1 traveling along the traveling direction D1. In the example shown in FIG. 5, each handover area 106 has an arc shape. However, for example, it may be a rectangular area of ​​an adjacent lane slightly ahead of the driver of the host vehicle V1, or an area in which the arc shape shown in FIG. 5 overlaps with a rectangular area of ​​an adjacent lane slightly ahead of the driver of the host vehicle V1. The controller 33 can recognize the adjacent lane, for example, by detecting white lines using an image captured by an exterior camera, which is an output signal of the exterior sensor 1. For example, as shown in FIG. 5, the handover area 106 is set so as to be adjacent to a blind spot area 107, which is a blind spot for the driver of the host vehicle V1.

[0033] The overtaking target vehicle determination unit 333 determines whether or not the other vehicle detected by the other vehicle detection unit 332 is a vehicle to be overtaken, in accordance with the determination conditions 323 stored in the storage unit 32.

[0034] The determination condition 323 includes at least one of the relative position and relative speed between the host vehicle and the other vehicle as a condition parameter. The condition based on the relative position between the host vehicle and the other vehicle is met when the change in the relative position between the host vehicle and the other vehicle over time satisfies a specific relationship. For example, the determination condition 323 includes a basic condition that the other vehicle that was located ahead of the host vehicle becomes located behind the host vehicle over time. The condition based on the relative speed between the host vehicle and the other vehicle is met when the relative speed between the host vehicle and the other vehicle over time satisfies a specific relationship. For example, the basic condition may be that the traveling speed of the host vehicle is faster than that of the other vehicle. Alternatively, the basic condition may be that the other vehicle that was located ahead of the host vehicle becomes located behind the host vehicle over time, and the traveling speed of the host vehicle is faster than that of the other vehicle.

[0035] For example, the overtaking target vehicle determination unit 333 may determine that another vehicle is a vehicle to be overtaken when the basic conditions are satisfied, and may determine that another vehicle is not a vehicle to be overtaken when the basic conditions are not satisfied.

[0036] The determination condition 323 may further include the state of the driver of the host vehicle V1 as a condition parameter. Since the state of the driver of the host vehicle V1 is considered to differ depending on whether the other vehicle detected by the other vehicle detection unit 332 is an overtaking target vehicle or not, the accuracy of the determination can be improved by having the overtaking target vehicle determination unit 333 make a determination based on the state of the driver of the host vehicle V1. For example, the determination condition 323 may include a first additional condition that the driver of the host vehicle V1 gazes at the other vehicle detected by the other vehicle detection unit 332 for a certain period of time. For example, the determination condition 323 may include a second additional condition that the driver of the host vehicle V1 designates the other vehicle detected by the other vehicle detection unit 332 by a gesture. For example, the determination condition 323 may include a third additional condition that the driver of the host vehicle V1 experiences an emotional change, such as becoming anxious.

[0037] It should be noted that which of the first, second, and third additional conditions is to be used may be set in advance by the driver.

[0038] For example, the overtaking target vehicle determination unit 333 may check the basic condition and at least one of the first to third additional conditions, and determine that the other vehicle is a vehicle to be overtaken when all of the checked conditions are met. Also, the overtaking target vehicle determination unit 333 may check the basic condition and a preset additional condition used for determination, and determine that the other vehicle is a vehicle to be overtaken when all of the checked conditions are met. In other words, the overtaking target vehicle determination unit 333 can determine whether the other vehicle is a vehicle to be overtaken, taking into account the state of the driver of the host vehicle V1.

[0039] The overtaking target vehicle monitoring unit 334 continues to monitor the overtaking target vehicle until the inter-vehicle distance between the host vehicle and the overtaking target vehicle exceeds the threshold value 324 stored in the memory unit 32. In other words, the overtaking target vehicle monitoring unit 334 tracks the overtaking target vehicle until the inter-vehicle distance between the host vehicle and the overtaking target vehicle exceeds the threshold value 324 stored in the memory unit 32. For example, the overtaking target vehicle monitoring unit 334 identifies the overtaking target vehicle based on vehicle information acquired from an external sensor and tracks the overtaking target vehicle until the inter-vehicle distance between the identified overtaking target vehicle and the host vehicle exceeds the threshold value. The vehicle information includes the vehicle number, shape, color, model, feature values ​​extracted from the image, etc. Specifically, the overtaking target vehicle monitoring unit 334 reads the vehicle number printed on the license plate of the overtaking target vehicle from an image captured by a camera to identify the overtaking target vehicle. The overtaking target vehicle monitoring unit 334 may also identify the overtaking target vehicle based on the color or shape of the overtaking target vehicle. The overtaking target vehicle monitoring unit 334 may extract feature amounts of the overtaking target vehicle from an image including the overtaking target vehicle captured by a camera, and identify the overtaking target vehicle. This allows the overtaking target vehicle monitoring unit 334 to identify the overtaking target vehicle and track it until it exceeds the threshold 324.

[0040] The overtaking target vehicle notification unit 335 notifies the driver of the host vehicle V1 about the overtaking target vehicle using the notification device 4. The overtaking target vehicle notification unit 335 continues to notify the driver of the host vehicle V1 until the inter-vehicle distance between the identified overtaking target vehicle and the host vehicle exceeds the threshold value 324. This can improve safety when changing lanes after overtaking.

[0041] Furthermore, the overtaking target vehicle notification unit 335 can issue a notification regarding the overtaking target vehicle in a situation where the driver of the host vehicle V1 is likely to change lanes after overtaking, that is, in a situation where at least one of the first additional condition, the second additional condition, and the third additional condition is satisfied in addition to the basic condition. Therefore, it is possible to issue a notification when it is likely that the driver will change lanes after overtaking, while suppressing unnecessary notifications when the driver will not change lanes after overtaking. This can further improve safety when changing lanes after overtaking.

[0042] <First example of vehicle detection processing> 6 is a flowchart showing a first example of vehicle detection processing executed by the controller 33 of the vehicle detection ECU 3 of FIG. 4. This flowchart shows the technical content of a computer program that causes a computer device to perform information processing. The computer program may be stored in various readable non-volatile recording media and provided (sold, distributed, etc.), or may be provided (sold, distributed, etc.) via a communication network. The computer program may consist of only one program, or may consist of multiple programs that work together.

[0043] The vehicle detection process shown in FIG. 6 is started when the host vehicle V1 starts and becomes capable of traveling.

[0044] In step S10, the controller 33 attempts to detect another vehicle in the adjacent lane ahead of the host vehicle V1. Specifically, the acquisition unit 331 of the controller 33 acquires an output signal from the vehicle exterior sensor 1. The other vehicle detection unit 332 of the controller 33 then checks whether or not another vehicle is present in the handover region 106 using the output signal from the vehicle exterior sensor 1. If the other vehicle is present in the handover region 106, the other vehicle detection unit 332 of the controller 33 detects the other vehicle in the adjacent lane ahead of the host vehicle V1. If the other vehicle is not present in the handover region 106, the other vehicle detection unit 332 of the controller 33 does not detect the other vehicle in the adjacent lane ahead of the host vehicle V1. Therefore, in the positional relationship shown in FIG. 7A, the other vehicle detection unit 332 of the controller 33 does not detect the other vehicle V2 in the adjacent lane LN1, but later, when the positional relationship shown in FIG. 7B is established, the other vehicle detection unit 332 detects the other vehicle V2 in the adjacent lane LN1.

[0045] If no other vehicle in the adjacent lane ahead of the host vehicle V1 is detected (NO in step S10), the process of step S10 is repeated.

[0046] On the other hand, if another vehicle in the adjacent lane ahead of the host vehicle V1 is detected (YES in step S10), the process proceeds to step S20. At this time, there may be a vehicle traveling ahead of the detected other vehicle in the same lane as the detected other vehicle, or a vehicle traveling ahead of the host vehicle V1 in the adjacent lane LN1 on the opposite side of the detected other vehicle. In this case, the detection of another vehicle in FIG. 6 (step S10) may be newly started. In other words, the vehicle detection process shown in FIG. 6 may be performed multiple times depending on the number of other vehicles.

[0047] In step S20, the controller 33 detects the state of the driver of the host vehicle V1. Specifically, the acquisition unit 331 of the controller 33 acquires the output signal of the interior sensor 2. Then, the overtaking target vehicle determination unit 333 of the controller 33 detects the state of the driver of the host vehicle V1 using the output signal of the interior sensor 2. When the processing of step S20 ends, the processing proceeds to step S30.

[0048] If the determination condition 323 does not include a condition based on the state of the driver of the host vehicle V1, step S20 may be omitted.

[0049] In step S30, the overtaking target vehicle determination unit 333 of the controller 33 uses the output signal of the outside vehicle sensor 1 and the output signal of the inside vehicle sensor 2 to determine whether the other vehicle V2 detected by the other vehicle detection unit 332 is a vehicle to be overtaken.

[0050] If it is not determined that the vehicle is a target vehicle to be overtaken (NO in step S30), the process returns to step S10.

[0051] On the other hand, if it is determined that the vehicle is a target vehicle to be overtaken (YES in step S30), the process proceeds to step S40.

[0052] In step S40, the overtaking target vehicle monitoring unit 334 of the controller 33 tracks the overtaking target vehicle and determines whether the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle is equal to or less than the threshold value 324. Here, the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle may be the distance L1 between the host vehicle V1 and the overtaking target vehicle shown in Figure 7C, or may be the distance L2 between the host vehicle V1 and the overtaking target vehicle in the traveling direction D1 shown in Figure 7C.

[0053] By executing the processing of step S40, after the host vehicle V1 has overtaken the target vehicle, the host vehicle V1 tracks the target vehicle until the inter-vehicle distance between the host vehicle V1 and the target vehicle exceeds the threshold 324, so the target vehicle can be tracked until a sufficient inter-vehicle distance (inter-vehicle distance exceeding the threshold 324) is secured. Furthermore, because the target vehicle is the tracking target (the target of continuous monitoring), it is possible to prevent monitoring of unnecessary vehicles and obstacles even if the threshold 324 is set broadly.

[0054] If the inter-vehicle distance between the host vehicle V1 and the vehicle to be overtaken is equal to or less than the threshold value 324 (YES in step S40), a sufficient inter-vehicle distance (inter-vehicle distance exceeding the threshold value 324) is not secured, and therefore the overtaking target vehicle notification unit 335 of the controller 33 uses the notification device 4 to notify that the inter-vehicle distance between the host vehicle V1 and the vehicle to be overtaken does not exceed the threshold value 324 (step S50). This allows the driver of the host vehicle V1 to understand that safety is not secured when changing lanes after overtaking.

[0055] If the notification device 4 includes a speaker, the speaker outputs a sound that imitates the exhaust sound of a vehicle to notify the driver that the inter-vehicle distance between the vehicle V1 and the vehicle to be overtaken does not exceed the threshold 324.

[0056] It is desirable that the overtaking target vehicle notification unit 335 of the controller 33 notify the driver with notification content according to the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle. For example, the shorter the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle, the louder the sound output from the speaker may be. Also, the longer the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle, the quieter the sound output from the speaker may be. This allows the driver of the host vehicle V1 to intuitively grasp the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle.

[0057] It is desirable that the overtaking target vehicle notification unit 335 of the controller 33 notify the driver with notification content according to the direction of the overtaking target vehicle relative to the host vehicle V1. For example, if the overtaking target vehicle is traveling in the adjacent lane on the right, sound may be output from a speaker arranged in the right front door of the host vehicle V1, and if the overtaking target vehicle is traveling in the adjacent lane on the left, sound may be output from a speaker arranged in the left front door of the host vehicle V1. This allows the driver of the host vehicle V1 to intuitively grasp the direction of the overtaking target vehicle relative to the host vehicle V1.

[0058] The overtaking target vehicle notification unit 335 of the controller 33 may provide a notification that combines notification content according to the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle and the direction of the overtaking target vehicle relative to the host vehicle V1. This allows the driver of the host vehicle V1 to intuitively grasp the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle and the direction of the overtaking target vehicle relative to the host vehicle V1.

[0059] If the notification device 4 includes a vibration device, the vibration device, for example, operates to notify the driver that the inter-vehicle distance between the vehicle V1 and the vehicle to be overtaken does not exceed the threshold value 324.

[0060] It is desirable that the overtaking target vehicle notification unit 335 of the controller 33 notify the driver with notification content according to the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle. For example, the shorter the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle, the greater the vibration of the vibration device. Also, the longer the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle, the smaller the vibration of the vibration device. This allows the driver of the host vehicle V1 to intuitively grasp the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle.

[0061] It is desirable that the overtaking target vehicle notification unit 335 of the controller 33 notify with notification content according to the direction of the overtaking target vehicle relative to the host vehicle V1. For example, if the overtaking target vehicle is traveling in the adjacent lane on the right, the vibration device located on the right of the pair of left and right vibration devices may be activated, and if the overtaking target vehicle is traveling in the adjacent lane on the left, the vibration device located on the right of the pair of left and right vibration devices may be activated. This allows the driver of the host vehicle V1 to intuitively grasp the direction of the overtaking target vehicle relative to the host vehicle V1.

[0062] The overtaking target vehicle notification unit 335 of the controller 33 may provide a notification that combines notification content according to the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle and the direction of the overtaking target vehicle relative to the host vehicle V1. This allows the driver of the host vehicle V1 to intuitively grasp the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle and the direction of the overtaking target vehicle relative to the host vehicle V1.

[0063] Moreover, the overtaking target vehicle notification unit 335 of the controller 33 may combine notification by sound and notification by vibration.

[0064] On the other hand, if the inter-vehicle distance between the vehicle V1 and the vehicle to be overtaken exceeds the threshold 324 (NO in step S40), a sufficient inter-vehicle distance (inter-vehicle distance exceeding the threshold 324) is secured, so the overtaking target vehicle monitoring unit 334 of the controller 33 ends tracking of the vehicle to be overtaken and erases the setting of the vehicle to be overtaken (step S60).

[0065] <Second example of vehicle detection processing> Fig. 8 is a flowchart showing a second example of the vehicle detection process executed by the controller 33 of the vehicle detection ECU 3 in Fig. 4. Differences between the flowchart in Fig. 8 and the flowchart in Fig. 6 will be described.

[0066] In the flowchart of FIG. 8, step S41 is provided between step S40 and step S50. The vehicle detection ECU 3 receives a signal indicating the state of the turn indicator from the turn indicator. In step S41, the overtaking target vehicle notification unit 335 of the controller 33 determines whether the turn indicator is flashing or not based on the information indicating the flashing state of the turn indicator acquired from the acquisition unit 331. If the turn indicator is flashing (YES in step S41), the process proceeds to step S50. As a result, the start of notification by the overtaking target vehicle notification unit 335 of the controller 33 is linked to the start of flashing of the turn indicator. On the other hand, if the turn indicator is not flashing (NO in step S41), the process returns to step S40.

[0067] <Third example of vehicle detection processing> Fig. 9 is a flowchart showing a third example of the vehicle detection process executed by the controller 33 of the vehicle detection ECU 3 in Fig. 4. Differences between the flowchart in Fig. 9 and the flowchart in Fig. 6 will be described.

[0068] In the flowchart of Fig. 9, step S42 is provided between step S40 and step S50. In step S41, the overtaking target vehicle monitoring unit 334 of the controller 33 determines whether or not the overtaking target vehicle is present in the adjacent lane. If the overtaking target vehicle is present in the adjacent lane (YES in step S42), the process proceeds to step S50. On the other hand, if the overtaking target vehicle has changed lanes from the adjacent lane to another lane (NO in step S42), for example, as shown in Fig. 7D or 7E, the process returns to step S40. This makes it possible to prevent a notification regarding the overtaking target vehicle that has moved away from the adjacent lane.

[0069] <Fourth example of vehicle detection processing> Fig. 10 is a flowchart showing a fourth example of the vehicle detection process executed by the controller 33 of the vehicle detection ECU 3 shown in Fig. 4. Differences between the flowchart in Fig. 10 and the flowchart in Fig. 6 will be described.

[0070] 10, step S51 is provided between step S40 and step S60. In step S51, the overtaking target vehicle monitoring unit 334 of the controller 33 determines whether the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle has exceeded the threshold value 324 for a certain period of time.

[0071] If it is determined that the predetermined time has continued (YES in step S51), the process proceeds to step S60. On the other hand, if it is not determined that the predetermined time has continued (NO in step S51), the process proceeds to step S50 because the overtaking target vehicle is closing the inter-vehicle distance. As a result, even if the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle temporarily exceeds the threshold, the overtaking target vehicle notification unit 335 will issue a notification when the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle again becomes equal to or less than the threshold. According to the vehicle detection method of the fourth example, even if the inter-vehicle distance between the host vehicle V1 and the overtaking target vehicle temporarily increases and then the inter-vehicle distance decreases again as the overtaking target vehicle increases its speed, the driver of the host vehicle V1 can be notified, thereby further improving the safety of lane changes.

[0072] <Notes> Various technical features disclosed in the description of the present invention may be modified in various ways without departing from the spirit of the technical creation. Furthermore, multiple embodiments and modifications disclosed in the description of the present invention may be combined to the extent possible.

[0073] For example, the notification device 4 may include a display device, and the vehicle detection ECU 3 may cause the display device to display a schematic representation of the positional relationship between the host vehicle V1 and another vehicle traveling in an adjacent lane, as shown in Figures 7A to 7C. The overtaking target vehicle notification unit 335 of the controller 33 may combine the notification by the display device with the notification by the above-mentioned sound or vibration.

[0074] When the display device schematically displays the positional relationship between the host vehicle V1 and another vehicle traveling in an adjacent lane, the display device may also display the inter-vehicle distance between the host vehicle V1 and the other vehicle traveling in the adjacent lane. When the display device schematically displays Fig. 7A, a display 202 relating to the inter-vehicle distance is included on the display screen 201 of the display device as shown in Fig. 11. The same applies when the display device schematically displays Fig. 7B and when the display device schematically displays Fig. 7C.

[0075] When the display device schematically displays the positional relationship between the host vehicle V1 and another vehicle traveling in an adjacent lane, the display device may display the vehicle speed of the host vehicle V1 and the vehicle speed of the other vehicle traveling in the adjacent lane. When the display device schematically displays Fig. 7A, the display screen 201 of the display device includes a display 203 relating to the vehicle speed of the host vehicle V1 and a display 204 relating to the vehicle speed of the other vehicle traveling in the adjacent lane, as shown in Fig. 12. The same applies when the display device schematically displays Fig. 7B or when the display device schematically displays Fig. 7C.

[0076] When the display device schematically displays the positional relationship between the host vehicle V1 and another vehicle traveling in an adjacent lane, the display device may also display a safety level. The safety level can be represented, for example, by a color or a mark. For example, when the safety level is represented by a color, the following display may be used. When the display device schematically displays FIG. 7A, the other vehicle traveling in the adjacent lane is displayed in a default color (e.g., white) CLR1 as shown in FIG. 13. When the display device schematically displays FIG. 7B, the other vehicle traveling in the adjacent lane is displayed in, for example, red CLR2 as shown in FIG. 14. When the display device schematically displays FIG. 7C, if the inter-vehicle distance between the host vehicle V1 and the other vehicle traveling in the adjacent lane is equal to or less than a threshold, the other vehicle traveling in the adjacent lane is displayed in, for example, red CLR2 as shown in FIG. 15. If the inter-vehicle distance between the host vehicle V1 and the other vehicle traveling in the adjacent lane exceeds the threshold, the other vehicle traveling in the adjacent lane is displayed in, for example, blue CLR3 as shown in FIG. 16. Instead of or in addition to displaying in different colors, a different mark may be displayed near the other vehicle V2 or superimposed on the other vehicle V2.

[0077] Furthermore, when the display device schematically displays the positional relationship between the host vehicle V1 and another vehicle traveling in an adjacent lane, the display device may display the lane in which the vehicle to be overtaken is traveling in a color different from the default color (e.g., gray). When the display device schematically displays Fig. 7B, the lane LN2 in which the vehicle to be overtaken is traveling is displayed in a color CLR4 different from the default color (e.g., gray), as shown in Fig. 17. The same applies when the display device schematically displays Fig. 7C.

[0078] Furthermore, when the display device schematically displays the positional relationship between the host vehicle V1 and another vehicle traveling in an adjacent lane, the display device may display the lane in which the host vehicle V1 is traveling in a color different from the other lanes. When the display device schematically displays Fig. 7A, the lane LN3 in which the host vehicle V1 is traveling is displayed in a color CLR5 different from the other lanes, as shown in Fig. 18. The same applies when the display device schematically displays Fig. 7B or when the display device schematically displays Fig. 7C.

[0079] The displays shown in Figures 11 to 18 may be implemented in combination as appropriate. For example, Figures 11 and 12 may be implemented in combination, and the display device may display the inter-vehicle distance between the host vehicle V1 and another vehicle traveling in an adjacent lane, the vehicle speed of the host vehicle V1, and the vehicle speed of the other vehicle traveling in the adjacent lane.

[0080] In the above-described embodiment, the overtaking target vehicle notification unit 335 of the controller 33 notifies the driver that the inter-vehicle distance between the host vehicle V1 and the vehicle to be overtaken does not exceed the threshold 324. However, conversely, the overtaking target vehicle notification unit 335 of the controller 33 may notify the driver that the inter-vehicle distance between the host vehicle V1 and the vehicle to be overtaken exceeds the threshold 324. This allows the driver of the host vehicle V1 to know that safety is ensured when changing lanes after overtaking when notified. The notification that the threshold 324 has been exceeded may be, for example, a voice message indicating that a lane change is possible, or a message displayed on a display device. Note that the overtaking target vehicle notification unit 335 of the controller 33 may notify the driver that the threshold 324 has not been exceeded and may notify the driver that the threshold 324 has been exceeded.

[0081] For example, when multiple other vehicles V2 exist in the same adjacent lane as shown in Fig. 7F, there may be multiple vehicles to be overtaken. In this case, the vehicle detection process flowchart may be executed for each of the multiple vehicles to be overtaken, or the vehicle detection process flowchart may be executed only for the vehicle to be overtaken ahead, and the setting of the vehicle to be overtaken behind may be deleted. [Explanation of symbols]

[0082] 1. Outside vehicle sensor 2. Vehicle interior sensors 3 Vehicle detection ECU 4. Alarm device 101 Vehicle 102 Left adjacent region 103 Right adjacent region 104 Left posterior area 105 Right posterior area 106 Handover Area 107 Blind spot area D1 Travel direction LN1 adjacent lane V1 Vehicle V2 Other vehicles

Claims

1. Detects other vehicles in adjacent lanes ahead of the vehicle, determining whether the other vehicle is a target vehicle to be overtaken based on at least one of a relative position and a relative speed between the host vehicle and the other vehicle; Identifying the target vehicle to be overtaken based on vehicle information acquired from an external sensor; tracking the identified overtaking target vehicle until the inter-vehicle distance between the identified overtaking target vehicle and the host vehicle exceeds a threshold value; Vehicle detection device.

2. The vehicle detection device according to claim 1 , wherein the notification is continued until the inter-vehicle distance exceeds the threshold value.

3. The vehicle detection device according to claim 2 , wherein the notification content is determined according to the inter-vehicle distance.

4. 4. The vehicle detection device according to claim 2, wherein the notification content is determined according to the direction of the target vehicle relative to the host vehicle.

5. The vehicle detection device according to claim 1 , wherein the vehicle detection device notifies the driver that the inter-vehicle distance has exceeded the threshold value.

6. The vehicle detection device according to claim 1 , wherein the vehicle detection device determines whether the other vehicle is the target vehicle to be overtaken based on at least one of the relative position and the relative speed and a state of the driver of the host vehicle.

7. Detects other vehicles in adjacent lanes ahead of the vehicle, determining whether the other vehicle is a target vehicle to be overtaken based on at least one of a relative position and a relative speed between the host vehicle and the other vehicle; Identifying the target vehicle to be overtaken based on vehicle information acquired from an external sensor; tracking the identified overtaking target vehicle until the inter-vehicle distance between the identified overtaking target vehicle and the host vehicle exceeds a threshold value; A vehicle detection method performed by a vehicle detection device.

8. Detecting another vehicle in an adjacent lane ahead of the vehicle; determining whether the other vehicle is a target vehicle to be overtaken based on at least one of a relative position and a relative speed between the host vehicle and the other vehicle; Identifying the target vehicle to be overtaken based on vehicle information acquired from an external sensor; tracking the identified target vehicle until the inter-vehicle distance between the target vehicle and the host vehicle exceeds a threshold; A vehicle detection program that causes a computer to execute the above.

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