Driving Support Devices

Abstract

To provide a driving support device which gives attention relating to a traffic light, which is detected based on a camera image acquired by a camera device imaging a front side of a vehicle, to a driver of the vehicle.SOLUTION: A driving support device gives attention while any one of a first condition and a second condition is established in a case where no preceding vehicle exists, and prohibits the giving of attention in a case where a preceding vehicle exists. The first condition is a condition that a main lamp of a traffic light indicates a stop signal instructing stop of vehicles and that no arrow lamp is detected below the main lamp. The second condition is a condition that the main lamp indicates the stop signal, an arrow lamp is detected and a permitted direction in which the arrow lamp permits travel of vehicles is not coincident with a future travel direction which is a direction of travel of vehicles in future.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a driving assistance device that alerts a driver of a vehicle to a traffic light. [Background technology]

[0002] A driving support device that issues the above-mentioned warning is known. Such a driving support device detects a traffic light in front of the vehicle based on a camera image acquired by a camera device capturing an image of the area in front of the vehicle.

[0003] For example, the driving assistance device described in Patent Document 1 (hereinafter, "the conventional device") issues a warning if the traffic light's arrow indicator is not detected and the traffic light's main indicator is displaying a stop signal (yellow or red) instructing the vehicle to stop. If the conventional device detects an arrow indicator, it issues a warning if the main indicator indicates a stop signal and the permitted direction does not match the future traveling direction.

[0004] The permitted direction is the direction in which the arrow light permits the vehicle to travel, and is the direction indicated by the arrow signal displayed by the arrow light. The future heading is the future direction of travel of the vehicle and is determined, for example, based on the direction of directional road markings on the lane the vehicle is traveling in. The directional road markings indicate the direction in which the lane allows the vehicle to travel. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-047565 Summary of the Invention

[0006] When there is a preceding vehicle ahead of the vehicle, the camera device is blocked by the preceding vehicle and cannot capture the traffic light of the traffic light, so the conventional device may not be able to detect the traffic light even if the traffic light is equipped with the traffic light. In this case, the conventional device issues a warning if the main light displays a stop signal. For this reason, even if the permitted direction and the future traveling direction match (even if a warning should not be issued), the conventional device may issue a warning. A warning issued erroneously may be annoying to the driver.

[0007] The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is to provide a driving assistance device that can reduce the possibility that a driver feels annoyed by a warning issued by mistake, by reducing the possibility that the warning is issued by mistake.

[0008] The driving assistance device of the present invention (hereinafter also referred to as the "device of the present invention") alerts the driver of a vehicle (VA) to a detected traffic light (TL) based on a camera image acquired by a camera device (21) that photographs the area in front of the vehicle (VA). The device of the present invention comprises: When there is no preceding vehicle (VB) located ahead of the vehicle (step 430 “No”, step 465 “No”), A first condition is that the main light of the traffic signal is displaying a stop signal instructing the vehicle to stop (step 425 "Yes"), and an arrow light is not detected below the main light (step 435 "No"); and A second condition is that the main light unit is displaying the stop signal (step 425 "Yes"), the arrow light unit is detected (step 435 "Yes"), and the permitted direction in which the arrow light unit permits the vehicle to travel does not match the future travel direction in which the vehicle is estimated to travel in the future (step 455 "No"); If any of the above is true, the warning is issued (step 440, step 515), If the preceding vehicle is present (step 430 “Yes”, step 465 “Yes”), the warning is prohibited. It is structured as follows.

[0009] According to the present invention, the device prohibits warnings when there is a preceding vehicle. This prevents a traffic light equipped with a traffic light from being erroneously issued due to the traffic light being blocked by a preceding vehicle and not being detected. This reduces the possibility that the driver will find the warnings annoying.

[0010] In one embodiment of the device of the present invention, If the vehicle distance (Dv) between the vehicle and another vehicle located ahead of the vehicle is longer than a predetermined threshold distance (Dvth) (step 465 "No"), it is determined that the preceding vehicle does not exist, If the vehicle distance is equal to or less than the threshold distance (step 465 "Yes"), it is determined that the preceding vehicle is present. It is structured as follows.

[0011] If the distance between the vehicles is longer than the threshold distance, the camera device can capture the arrow light without being blocked by the preceding vehicle, and the arrow light is likely to be detected. According to this aspect, even if there is another vehicle in front of the vehicle, if the distance between the vehicles is longer than the threshold distance, the other vehicle is not detected as a preceding vehicle, and a warning is issued if either the first condition or the second condition is satisfied. This increases the likelihood that a warning will be issued in a situation where a warning should be issued, even if there is another vehicle.

[0012] In one embodiment of the device of the present invention, When the preceding vehicle is present (step 430 “Yes” shown in FIG. 7, step 465 “Yes” shown in FIG. 7) and the length (H) between the upper end (UE) of the preceding vehicle and the lower end (BE) of the main light unit is equal to or longer than a predetermined threshold length (Hth) (step 720 “No”), if either the first condition or the second condition is satisfied, the warning is issued, If the preceding vehicle exists (step 430 “Yes” shown in FIG. 7, step 465 “Yes” shown in FIG. 7) and the length is less than the threshold length (step 720 “Yes”), prohibit the warning. It is structured as follows.

[0013] When the length between the top of the preceding vehicle and the bottom of the main light is equal to or greater than the threshold length, if the traffic light is equipped with an arrow light, the arrow light is likely to be detected. According to this aspect, even if a preceding vehicle exists, if the length is equal to or greater than the threshold length, a warning is issued when either the first condition or the second condition is satisfied, and if the length is less than the threshold length, warning is prohibited. This increases the likelihood that a warning will be issued in a situation where a warning should be issued, even if a preceding vehicle exists.

[0014] In one embodiment of the device of the present invention, The vehicle is configured to determine the future direction of travel based on the direction in which the lane in which the vehicle is currently traveling allows the vehicle to travel and the indication direction of the turn signals (33L, 33R) of the vehicle.

[0015] According to this aspect, the future traveling direction can be accurately determined, thereby reducing the possibility of an erroneous warning being issued.

[0016] In the above description, in order to facilitate understanding of the invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses with respect to the configuration of the invention corresponding to the embodiments. However, each component of the invention is not limited to the embodiments defined by the names and / or symbols. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic system configuration diagram of a driving assistance device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of a road near the intersection. [Diagram 3]FIG. 3 is a diagram illustrating an outline of an embodiment of the present invention. [Figure 4] FIG. 4 is a flowchart showing an attention-call start determination routine executed by the CPU of the driving assistance ECU shown in FIG. [Diagram 5] FIG. 5 is a flowchart showing an attention calling routine executed by the CPU of the driving assistance ECU shown in FIG. [Figure 6] FIG. 6 is a schematic explanatory diagram of a first modified example of the embodiment of the present invention. [Figure 7] FIG. 7 is a flowchart showing a part of an attention-call start determination routine executed by the CPU of the driving assistance ECU in the first modified example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] <Configuration> As shown in FIG. 1, a driving assistance device (hereinafter, referred to as "this assistance device") 10 according to an embodiment of the present invention is mounted on a vehicle VA.

[0019] The assistance device 10 includes a driving assistance ECU 20 (hereinafter, referred to as "DSECU 20").

[0020] An ECU is a control unit (Electronic Control Unit) that includes a microcomputer as its main component, and is sometimes called a "controller." The microcomputer includes a CPU, ROM, RAM, and an interface (I / F), etc. These ECUs are connected to each other via a Controller Area Network (CAN) so that they can exchange data with each other. The CPU realizes various functions by executing instructions (programs, routines) stored in the ROM. The functions of this ECU may be distributed among multiple ECUs.

[0021] The assistance device 10 includes a wheel speed sensor 21, a camera device 22, a millimeter wave radar device 23, a brake operation amount sensor 24, a yaw rate sensor 25, a turn signal lever 26, a speaker 31, a display 32, a left turn signal 33L, and a right turn signal 33R. These are connected to the DSECU 20 so as to be able to exchange data.

[0022] The wheel speed sensor 21 is provided for each wheel of the vehicle VA. Each wheel speed sensor 21 generates one wheel pulse signal each time the corresponding wheel rotates a predetermined angle. The DSECU 20 counts the number of pulses per unit time of the wheel pulse signal received from each wheel speed sensor 21, and obtains the rotation speed of each wheel based on the number of pulses. Then, the DSECU 20 obtains a vehicle speed Vs indicating the speed of the vehicle VA based on the wheel speed of each wheel. As an example, the DSECU 20 obtains the average value of the wheel speeds of the four wheels as the vehicle speed Vs.

[0023] The camera device 22 is disposed at the center upper part of the windshield inside the vehicle VA. The camera device 22 acquires an image (hereinafter also referred to as a “camera image”) of a predetermined area in front of the vehicle VA every time a predetermined time elapses, and transmits the camera image to the driving assistance ECU 20.

[0024] The millimeter-wave radar device 23 transmits millimeter waves ahead of the vehicle VA. The millimeter-wave radar device 23 is a well-known sensor that detects an object by receiving millimeter waves (reflected waves) reflected by the object. Based on the received reflected waves, the millimeter-wave radar device 23 acquires the distance to the object (object distance), the relative speed (object relative speed) Vr of the object with respect to the vehicle VA, and the direction of the object. Then, the millimeter-wave radar device 23 transmits "radar object information including the object distance, object relative speed Vr, and object direction" to the DSECU 20 every time a predetermined time elapses.

[0025] The brake operation amount sensor 24 detects the operation amount of a brake pedal (not shown) of the vehicle VA (i.e., the brake pedal operation amount BP) and generates a detection signal representing the brake pedal operation amount BP. Note that, instead of the brake operation amount sensor 24, the assistance device 10 may be provided with a brake switch that detects whether or not the brake pedal is being operated.

[0026] The yaw rate sensor 25 detects the yaw rate of the vehicle VA and generates a detection signal indicative of the yaw rate. The sign of the yaw rate determines whether the yaw rate is in the left or right direction.

[0027] The turn signal lever 26 is disposed near a steering wheel (not shown). When the driver operates the turn signal lever 26 in a left blinking direction (e.g., upward), the left turn signal 33L blinks. When the driver operates the turn signal lever 26 in a right blinking direction (e.g., downward), the right turn signal 33R blinks.

[0028] The speaker 31 is disposed in the passenger compartment of the vehicle VA, and emits a buzzer sound in response to an attention-calling command from the driving assistance ECU 20. The display 32 is disposed in a position inside the vehicle VA that is "visible to the driver seated in the driver's seat."

[0029] The detection process based on the camera image performed by the driving assistance ECU 20 will be described with reference to Fig. 2. In the detection process, the DSECU 20 detects traffic lights TL, white lines WL, and other vehicles.

[0030] <Detection of traffic light TL> The DSECU 20 detects a traffic light TL present ahead of the vehicle VA based on the camera image. More specifically, the DSECU 20 detects a main light unit ML of the traffic light TL that is disposed opposite the vehicle VA at the intersection CP into which the vehicle VA is about to enter.

[0031] Based on the camera image, the DSECU20 identifies (detects) whether the main light unit ML of the traffic light TL is displaying a green light B, a yellow light Y, or a red light R. If the main light unit ML is displaying either a yellow light Y or a red light R, the main light unit ML is instructing the vehicle VA to stop. The yellow light Y and the red light R may be referred to as "stop signals." The green light B may be referred to as "permission signal."

[0032] When the DSECU 20 detects the arrow light AL of the traffic light TL based on the camera image, the DSECU 20 detects the direction of the arrow signal displayed by the arrow light AL (left arrow signal LL, straight arrow signal SL, right arrow signal RL). The direction of the arrow signal is the direction in which the vehicle VA is permitted to travel.

[0033] Furthermore, the DSECU 20 detects the relative position (direction and distance) of the traffic light TL with respect to the vehicle VA based on the camera image.

[0034] <White line recognition> The DSECU 20 detects white lines WL (lane dividing lines) on the road based on the camera image, and identifies the relative position of the white lines WL with respect to the vehicle VA. Based on the relative positions of the white lines WL, the DSECU 20 identifies the white line WL located on the left side of the vehicle VA and closest to the vehicle VA as the left white line LWL. Similarly, based on the relative positions of the white lines WL, the DSECU 20 identifies the white line WL located on the right side of the vehicle VA and closest to the vehicle VA as the right white line RWL. Then, the DSECU 20 identifies the lane divided by the left white line LWL and the right white line RWR as the driving lane LA in which the vehicle VA is currently traveling.

[0035] Furthermore, the DSECU 20 detects road markings D based on the camera image. The road markings D include a stop line SD provided just before the intersection CP, and a directional road marking AD that indicates with an arrow the direction in which the vehicle VA can proceed (the direction in which the vehicle VA is permitted to proceed). Note that the arrow indicated by the directional road marking AD may indicate not only one direction but also two directions.

[0036] Furthermore, the DSECU 20 determines the distance from the vehicle VA to the stop line SD of the driving lane LA. Furthermore, the DSECU 20 determines the direction permitted by the driving lane LA based on the directional road marking AD of the driving lane LA. Since the vehicle VA is highly likely to travel in the direction of the directional road marking AD, the direction of the directional road marking AD is also expressed as "the future travel direction, which is the future travel direction of the vehicle VA."

[0037] In addition, the DSECU 20 detects other vehicles based on the camera image and identifies the relative positions of the other vehicles with respect to the vehicle VA (the distance to the other vehicles and the direction of the other vehicles). Then, the DSECU 20 determines the relative positions of the other vehicles with respect to the vehicle VA based on the identified relative positions and the radar object information.

[0038] <Caution> When either the first or second condition below is satisfied, the DSECU 20 determines that the start condition is satisfied and issues a warning. In detail, the DSECU 20 transmits an warning command to the speaker 31 to cause the speaker 31 to emit a buzzer sound.

[0039] First condition: The main light unit ML displays a stop signal and the DSECU20 does not detect the arrow light unit AL. Second condition: The main light unit ML displays a stop signal, the DSECU20 detects the arrow light unit AL, and the direction of the arrow signal displayed on the arrow light unit AL (permitted direction) does not match the direction of the directional road marking AD (future travel direction).

[0040] When the arrow light AL displays multiple arrow signals, if the future travel direction does not match any of the directions of these arrow signals (permitted directions), the DSECU 20 determines that the permitted direction does not match the future travel direction. When the directional road marking AD displays multiple arrows, if the permitted direction does not match any of the directions of these arrows (future travel direction), the DSECU 20 determines that the permitted direction does not match the future travel direction.

[0041] In the example shown in Fig. 2, the main light ML displays a red signal R, and the DSECU20 detects the arrow light AL. Furthermore, the arrow light AL displays a left arrow signal LL (i.e., the permitted direction is the left direction), and the directional road marking AD of the travel lane LA is a straight-ahead direction (the future travel direction is a straight-ahead direction), so the permitted direction and the future travel direction do not match. Therefore, the second condition is satisfied, and the DSECU20 issues a warning.

[0042] <Overview of operation> An overview of the operation of the DSECU 20 of the device 10 of the present invention will now be described with reference to FIG. When a preceding vehicle VB is present ahead of the vehicle VA, the camera device 22 may not be able to capture an image of the arrow light AL disposed below the main light ML because the image of the arrow light AL is blocked by the preceding vehicle VB. In this case, the camera image does not include an image of the arrow light AL, so the DSECU 20 cannot detect the arrow light AL. Therefore, if the main light ML displays a stop signal, the first condition is met and the DSECU 20 issues a warning.

[0043] Even if the direction of the arrow signal displayed by an arrow light AL that is not detected by DSECU20 (i.e., the permitted direction) coincides with the future traveling direction, DSECU20 may erroneously issue a warning.

[0044] Therefore, in the present embodiment, when a preceding vehicle VB is present ahead of the vehicle VA, the DSECU 20 prohibits the warning from being issued erroneously. This can reduce the possibility of the warning being issued erroneously even in a situation where the presence of the preceding vehicle VB makes it easier for the warning to be issued erroneously.

[0045] (Specific operation) <Caution start determination routine> The CPU of the DSECU 20 (hereinafter, when written as "CPU", it refers to the CPU of the DSECU 20 unless otherwise specified) executes an attention start determination routine shown by the flowchart in FIG. 4 every time a predetermined time has elapsed.

[0046] Therefore, at a predetermined timing, the CPU starts the process from step 400 in Fig. 4, and proceeds to step 405. In step 405, the CPU determines whether or not the value of the execution flag Xexe is "0".

[0047] The value of the execution flag Xexe is set to "1" when either the first condition or the second condition is satisfied (i.e., when the start condition is satisfied), and is set to "0" when the end condition described below is satisfied. The value of the execution flag Xexe is also set to "0" in the initial routine. The initial routine is a routine executed by the CPU when the ignition key switch (not shown) of the vehicle VA is changed from the off position to the on position.

[0048] If the value of the execution flag Xexe is "0", the CPU determines "Yes" in step 405 and executes steps 410 to 420 in order. Step 410 : The CPU acquires a camera image from the camera device 22 . Step 415: The CPU acquires radar object information from the millimeter wave radar device 23. Step 420: The CPU determines whether or not a traffic light TL exists based on the camera image. If no traffic light TL is present, the CPU makes a "No" determination in step 420, proceeds to step 495, and temporarily ends this routine.

[0049] On the other hand, if a traffic light TL is present when the CPU proceeds to step 420, the CPU determines "Yes" in step 420 and proceeds to step 425. In step 425, the CPU determines whether the main light unit ML of the traffic light TL is displaying a stop signal. If the main light unit ML is not displaying a stop signal, the CPU judges "No" in step 425, proceeds to step 495, and temporarily ends this routine.

[0050] On the other hand, if the main light unit ML is displaying a stop signal when the CPU proceeds to step 425, the CPU determines "Yes" in step 425 and proceeds to step 430. In step 430, the CPU determines whether or not another vehicle is present ahead of the vehicle VA.

[0051] If there is no vehicle ahead of the vehicle VA, the CPU determines "No" in step 430 and proceeds to step 435. In step 435, the CPU determines whether or not the arrow light AL is detected below the main light ML in the camera image.

[0052] If the arrow lamp AL has not been detected, the CPU determines "No" in step 435, and proceeds to step 440. In step 440, the CPU determines whether the brake pedal operation amount BP is equal to or less than a predetermined threshold operation amount BPth.

[0053] If the brake pedal operation amount BP is equal to or less than the threshold operation amount BPth, the CPU determines that the driver has not depressed the brake pedal to stop the vehicle VA in front of the traffic light TL. In other words, the CPU determines that the driver has no intention of decelerating to stop the vehicle VA in front of the traffic light TL. In this case, the CPU determines that the first condition is satisfied. Then, the CPU determines "Yes" in step 440 and proceeds to step 445, where it sets the value of the execution flag Xexe to "1". After that, the CPU proceeds to step 495 and temporarily ends this routine. In this routine, each of the first and second conditions further includes a condition that the brake pedal operation amount BP is equal to or less than a threshold operation amount BPth.

[0054] On the other hand, if the brake pedal operation amount BP is greater than the threshold operation amount BPth, the CPU determines that the driver intends to decelerate. In this case, the CPU determines "No" in step 440, proceeds to step 495, and ends this routine.

[0055] On the other hand, if the arrow light AL is detected when the CPU proceeds to step 435, the CPU determines "Yes" in step 435 and executes steps 450 to 460 in order. Step 450: The CPU identifies the permitted direction based on the arrow signal displayed by the arrow light AL. Step 455: The CPU determines the future traveling direction based on the directional road marking AD. Step 460: The CPU determines whether or not the permitted direction and the future traveling direction match.

[0056] If the permitted direction and the future traveling direction do not match, the CPU determines "No" in step 460 and proceeds to step 440. If the brake pedal operation amount BP is equal to or less than the threshold operation amount BPth, the CPU determines that the second condition is satisfied. Then, the CPU determines "Yes" in step 440 and sets the value of the execution flag Xexe to "1" in step 445. After that, the CPU proceeds to step 495 and temporarily ends this routine.

[0057] If the permitted direction and the future traveling direction match when the CPU proceeds to step 460, the CPU determines "Yes" in step 460, proceeds to step 495, and temporarily ends this routine.

[0058] If there is another vehicle ahead of the vehicle VA when the CPU proceeds to step 430, the CPU determines "Yes" in step 430 and proceeds to step 465. In step 435, the CPU identifies the inter-vehicle distance Dv between the vehicle VA and the other vehicle, and determines whether the inter-vehicle distance Dv is equal to or less than a predetermined threshold distance Dvth.

[0059] If the inter-vehicle distance Dv is longer than the threshold distance Dvth, the CPU does not detect another vehicle in front of the vehicle VA as a preceding vehicle VB (i.e., it determines that a preceding vehicle VB does not exist). In this case, the CPU determines "No" in step 465 and executes the processing from step 435 onwards. Therefore, if either the first condition or the second condition is satisfied, the value of the execution flag Xexe is set to "1".

[0060] On the other hand, if the inter-vehicle distance Dv is equal to or less than the threshold distance Dvth, the CPU detects another vehicle in front of the vehicle VA as the preceding vehicle VB (i.e., determines that the preceding vehicle VB exists). In this case, the CPU determines "Yes" in step 465, proceeds to step 495, and temporarily ends this routine. Therefore, when the preceding vehicle VB is detected, the value of the execution flag Xexe is not set to "1", so the CPU does not issue a warning (i.e., prohibits issuing a warning) even if either the first condition or the second condition is met.

[0061] If the value of the execution flag Xexe is "1" when the CPU proceeds to step 405, the CPU determines "No" in step 405, proceeds to step 495, and temporarily ends this routine.

[0062] <Attention routine> The CPU executes a warning routine shown in the flowchart of FIG. 5 every time a predetermined time period elapses.

[0063] 5, and proceeds to step 505. In step 505, the CPU determines whether the value of the execution flag Xexe is "1".

[0064] If the value of the execution flag Xexe is "0", the CPU makes a "No" determination in step 505, proceeds to step 595, and temporarily ends this routine.

[0065] If the value of the execution flag Xexe is “1”, the CPU determines “Yes” in step 505 and proceeds to step 510. In step 510, the CPU determines whether or not a predetermined end condition is met by satisfying at least one of the following conditions 1 to 5.

[0066] Condition 1: The CPU no longer detects the traffic light TL that it had detected when either the first condition or the second condition was satisfied. Condition 2: The distance traveled by the vehicle VA from the time the warning was initiated has exceeded a specified distance. Condition 3: Vehicle VA has made a right turn or a left turn (hereinafter referred to as a "right / left turn"). Condition 4: The vehicle VA has stopped. Condition 5: The main light ML starts displaying the green signal B.

[0067] ·Condition 1 The CPU acquires a new camera image, and if the camera image does not include an image of the traffic light TL, determines that condition 1 is satisfied. ·Condition 2 The CPU determines the distance traveled by the vehicle VA based on the number of wheel pulse signals generated by the wheel speed sensor 21 from the time when the warning is started, and determines whether the distance traveled is equal to or greater than a predetermined distance. ·Condition 3 The CPU determines the yaw rate based on the detection signal from the yaw rate sensor 25, and if the magnitude of the yaw rate is equal to or greater than a predetermined value, determines that the vehicle VA has made a right or left turn.

[0068] ·Condition 4 The CPU determines, based on the vehicle speed Vs determined based on the wheel pulse signal from the wheel speed sensor 21, whether the vehicle VA has stopped. ·Condition 5 The CPU determines whether or not the main light unit ML should display the green signal B based on the newly acquired camera image.

[0069] If none of the above conditions 1 to 5 is met (i.e., the termination condition is not met), the CPU determines "No" in step 510 and proceeds to step 515. In step 515, the CPU transmits an attention command to the speaker 31, proceeds to step 595, and ends this routine. When the speaker 31 receives the attention command, it emits a buzzer sound.

[0070] On the other hand, if at least one of the above conditions 1 to 5 is satisfied (i.e., if the termination condition is satisfied), the CPU determines "Yes" in step 510 and proceeds to step 520. In step 520, the CPU sets the value of the execution flag Xexe to "0", proceeds to step 595, and temporarily ends this routine.

[0071] As described above, the device of the present invention does not set the value of the execution flag Xexe to "1" (i.e., prohibits warning) when the preceding vehicle VB is present. Even if the traffic light TL is equipped with an arrow light AL and the permitted direction and the future traveling direction match, the arrow light AL is blocked by the preceding vehicle VB and cannot be detected, so that the possibility of erroneous warning being issued can be reduced.

[0072] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention.

[0073] (First Modification) An outline of the operation of the DSECU 20 of the vehicle control device 10 according to the first modified example will be described with reference to FIG. Even when the preceding vehicle VB is detected, if the vertical length H between the upper end UE of the preceding vehicle VB and the lower end BE of the main light unit ML is equal to or greater than a predetermined threshold length Hth, and if either the first condition or the second condition is satisfied, the DSECU 20 issues a warning. Note that if the length H is less than the threshold length Hth, the DSECU 20 prohibits the warning.

[0074] The DSECU20 obtains the threshold length Hth by adding the "main light unit length Hml representing the vertical length between the upper end UE' and the lower end BE of the main light unit ML" to the predetermined length Hd. Note that the length used in this modification may be any length in the camera image.

[0075] When the length H is equal to or greater than the threshold length Hth, the camera device 22 can capture an image of the arrow light AL provided on the traffic light TL without being blocked by the preceding vehicle VB. Therefore, when the traffic light TL is provided with the arrow light AL, the DSECU 20 can reliably detect the arrow light AL. According to the first modification, even if the preceding vehicle VB is detected, if the length H is equal to or greater than the threshold length Hth and either the first condition or the second condition is satisfied, a warning is issued. This increases the likelihood that a warning will be issued in a situation where a warning should be issued, while reducing the likelihood that a warning will be issued erroneously.

[0076] The CPU of the DSECU 20 of the first modification executes the routine shown in Fig. 7 every time a predetermined time elapses instead of the attention call start determination routine shown in Fig. 4, and executes the routine shown in Fig. 5 every time a predetermined time elapses. The CPU executes the routines shown in Fig. 8 to Fig. 10 every time a predetermined time elapses. In FIG. 7, steps that perform the same processes as the steps shown in FIG. 4 are given the same reference numerals as those used in FIG. 7, and descriptions thereof will be omitted.

[0077] <Caution start determination routine> At a predetermined timing, the CPU starts the process from step 700, and if the value of the execution flag Xexe is "0", it judges "Yes" in step 405 shown in Fig. 7. After that, the CPU executes steps 410 to 420 shown in Fig. 7.

[0078] When the traffic light TL is detected and the traffic light TL is displaying a stop signal, the CPU makes a "Yes" determination in each of step 420 and step 425 shown in FIG. 7, and proceeds to step 430 shown in FIG.

[0079] When there is another vehicle ahead of the vehicle VA and the inter-vehicle distance Dv is equal to or less than the threshold distance Dvth, the CPU judges "Yes" in each of steps 430 and 465 shown in FIG.

[0080] Step 705: The CPU identifies the upper end UE' and the lower end BE of the main light unit ML based on the camera image, and identifies the main light unit length Hml in the vertical direction between the upper end UE' and the lower end BE. Step 710: The CPU obtains the threshold length Hth by adding the main lamp length Hml and the predetermined length Hd. Step 715: The CPU identifies the length H based on the camera image. Step 720: The CPU determines whether the length H is less than the threshold length Hth.

[0081] If the length H is greater than or equal to the threshold length Hth, the CPU judges "No" in step 720 and proceeds to processing from step 435 onwards shown in Figure 7, and sets the value of the execution flag Xexe to "1" if either the first condition or the second condition is met.

[0082] On the other hand, if the length H is less than the threshold length Hth, the CPU determines "Yes" in step 720, proceeds to step 795, and ends this routine. Therefore, if the length H is less than the threshold length Hth, the CPU does not set the value of the execution flag Xexe to "1" (i.e., prohibits issuing a warning) even if either the first condition or the second condition is satisfied.

[0083] (Second Modification) In the above embodiment, the DSECU 20 determines the future traveling direction based on the directional road marking AD. In the second modified example, the DSECU 20 determines the future traveling direction based on the indication directions of the blinkers 33L and 33R.

[0084] When the turn signal lever 26 is operated in a left blinking direction (e.g., upward), the left turn signal 33L blinks. In this case, since the driver is likely to move the vehicle VA to the left, the DSECU 20 determines that the future traveling direction will be the left direction. When the turn signal lever 26 is operated in a right blinking direction (e.g., downward), if the right turn signal switch 26R detects the driver's operation, the right turn signal 33R blinks. In this case, since the driver is highly likely to move the vehicle VA to the right, the DSECU 20 determines that the future traveling direction will be to the right. If the blinker lever 26 is not operated, the driver is likely to drive the vehicle VA straight, and therefore the DSECU 20 determines that the future traveling direction will be a straight direction.

[0085] DSECU 20 may determine the future direction of travel based on road signs indicating the direction in which lanes permit travel of vehicle VA.

[0086] (Third Modification) The first condition and the second condition may further include a condition that the distance Dt from the vehicle VA to the traffic light TL is a predetermined threshold distance Dtth. The DSECU 20 may obtain the threshold distance Dtth based on the current vehicle speed Vs as follows. The DSECU 20 calculates a required stopping distance Dn that the vehicle VA needs to travel before stopping at a position a predetermined distance Dd before the traffic light TL, based on the current vehicle speed Vs, on the assumption that the vehicle VA has decelerated at a predetermined deceleration. Then, the DSECU 20 obtains a value obtained by adding the required stopping distance Dn and the predetermined distance Dd as a threshold distance Dtth.

[0087] (Fourth Modification) In the above embodiment, the CPU issues a buzzer sound from the speaker 31 as a warning. In the third modified example, the CPU issues a flashing display of a "traffic light icon representing the traffic light TL" on the display 32 as a warning. The CPU may also flash the traffic light icon on the display 32 while issuing a buzzer sound from the speaker 31.

[0088] (Fifth Modification) The millimeter wave radar device 23 may be a remote sensing device that can detect an object by transmitting a wireless medium instead of a millimeter wave and receiving the reflected wireless medium. Furthermore, the vehicle control device 10 does not have to include the millimeter wave radar device 23.

[0089] (Sixth Modification) This support device 10 is applicable not only to the above-mentioned engine vehicles, but also to hybrid vehicles (HEVs: Hybrid Electric Vehicles), plug-in hybrid electric vehicles (PHEVs: Plug-in Hybrid Electric Vehicles), fuel cell electric vehicles (FCEVs: Fuel Cell Electric Vehicles), and battery electric vehicles (BEVs: Battery Electric Vehicles). [Explanation of symbols]

[0090] 10...driving assistance device, 20...driving assistance ECU, 22...camera device, 31...speaker, 32...display, TL...traffic light, ML...main light unit, AL...arrow light unit, AD...directional road marking, VB...preceding vehicle.

Claims

1. A driving assistance device that alerts a driver of a vehicle to a detected traffic signal based on a camera image acquired by a camera device that captures an image of a scene ahead of the vehicle, When there is no preceding vehicle in front of the vehicle, A first condition is that a main light of the traffic signal is displaying a stop signal instructing the vehicle to stop, and an arrow light is not detected below the main light; and A second condition that the main light unit is displaying the stop signal, the arrow light unit is detected, and the permitted direction in which the arrow light unit permits the vehicle to travel does not match a future travel direction that is a future travel direction of the vehicle; When any of the above is true, the above-mentioned warning is issued, prohibiting the warning when the preceding vehicle is present; It was configured as follows: Driving assistance device.

2. The driving assistance device according to claim 1, If the distance between the vehicle and another vehicle located ahead of the vehicle is longer than a predetermined threshold distance, it is determined that the preceding vehicle does not exist; If the vehicle-to-vehicle distance is equal to or less than the threshold distance, it is determined that the preceding vehicle is present. It was configured as follows: Driving assistance device.

3. In the driving assistance device according to any one of claims 1 and 2, determining the future direction of travel based on a direction in which the lane in which the vehicle is currently traveling permits the vehicle to travel and a direction in which a turn signal of the vehicle is indicated; Driving assistance device.

Images