Preceding vehicle departure notification device and method

Abstract

To provide a preceding vehicle departure notification device and method capable of making a necessary notification when there is a preceding vehicle stopped ahead of a preceding vehicle. [Solution] A preceding vehicle departure notification device includes a forward situation detection device that detects the situation ahead of the vehicle, and a driving assistance ECU that controls the notification device to notify the driver of the vehicle that the preceding vehicle has started when the vehicle does not start even though the preceding vehicle has started. When there is a preceding vehicle ahead of the stopped vehicle and there is a stopped further preceding vehicle ahead of the preceding vehicle, the driving assistance ECU sets a judgment reference line at a predetermined distance from the further preceding vehicle to the vehicle, and when it determines, based on the situation ahead of the vehicle detected by the forward situation detection device, that the preceding vehicle has moved forward but the vehicle cannot move forward beyond the judgment reference line, the driving assistance ECU reduces the appeal of the notification.

Description

[Technical Field]

[0001] The present invention relates to a preceding vehicle departure notification device and method for a vehicle such as an automobile. [Background technology]

[0002] As one of the driving assistance devices for vehicles such as automobiles, there is known a preceding vehicle departure notification device that notifies the driver of the host vehicle that the preceding vehicle has started moving when the host vehicle and the preceding vehicle are stopped and the host vehicle does not start moving even though the preceding vehicle has started moving.

[0003] For example, Patent Document 1 listed below describes a vehicle control device that starts its own vehicle when it determines that the preceding vehicle and adjacent vehicles have started moving, but does not start its own vehicle when it determines that the preceding vehicle has started moving but does not determine that the adjacent vehicle has started moving.

[0004] This type of control device can prevent the vehicle from starting and the notification that the preceding vehicle has started, unless an adjacent vehicle starts, in cases where the preceding vehicle makes an erroneous start or moves to a side road, store, etc. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-86958 Summary of the Invention

[0006] [Problem to be solved by the invention] Even if the preceding vehicle starts moving, or even if the preceding vehicle and adjacent vehicles start moving, the distance that the host vehicle can move forward after starting may be limited. In such cases, it is necessary not to notify the driver of the host vehicle that the preceding vehicle has started moving. In particular, if there is a preceding vehicle that is stopped in front of the preceding vehicle, even if the preceding vehicle starts moving, the preceding vehicle and the host vehicle will be prevented from moving forward by the preceding vehicle. Therefore, if a notification is made even though the distance that the host vehicle can move forward is limited, it is inevitable that the driver will feel annoyed.

[0007] The present invention provides a preceding vehicle departure notification device and method that, when there is a stopped preceding vehicle ahead of the preceding vehicle, can provide necessary notifications while reducing the risk of the driver feeling annoyed by changing the appeal of the notification based on the distance that the vehicle can advance relative to the preceding vehicle.

[0008] [Means for solving the problems and effects of the invention] According to the present invention, there is provided a preceding vehicle departure notification device (100) including a forward situation detection device (target information acquisition device 18) that detects the situation ahead of the host vehicle (102), and a control unit (driving assistance ECU 10) that controls a notification device (56) to notify the driver of the host vehicle that the preceding vehicle has started moving when the host vehicle does not start moving even though the preceding vehicle (110) has started moving.

[0009] When a preceding vehicle (110) is in front of the stopped host vehicle and a further preceding vehicle (112) is stopped in front of the preceding vehicle, the control unit (driving assistance ECU10) sets a judgment reference line (114) at a predetermined distance (L) from the further preceding vehicle toward the host vehicle, and when it determines that the preceding vehicle has moved forward based on the situation ahead of the host vehicle detected by the forward situation detection device, but that the host vehicle cannot move forward beyond the judgment reference line, the control unit is configured to reduce the appeal of the notification (S80, S100, S160, S180).

[0010] Furthermore, according to the present invention, there is provided a preceding vehicle departure notification method for notifying the driver of the own vehicle (102) that the preceding vehicle (110) has started moving when the own vehicle (102) does not start moving even though the preceding vehicle (110) has started moving.

[0011] The method for notifying the departure of a preceding vehicle includes a step (S40) of setting a judgment reference line (114) at a position a predetermined distance (L) from the preceding vehicle toward the host vehicle when a preceding vehicle (110) is present ahead of the host vehicle (102) that is stopped and a further preceding vehicle (112) that is stopped ahead of the preceding vehicle, and steps (S80, S100, S160, S180) of reducing the appeal of the notification when it is determined that the preceding vehicle has moved forward but the host vehicle cannot move forward beyond the judgment reference line.

[0012] According to the preceding vehicle departure notification device and method, when there is a preceding vehicle ahead of the stopped host vehicle and there is a preceding vehicle ahead of the preceding vehicle that is also stopped ahead of the preceding vehicle, a determination reference line is set at a position a predetermined distance from the preceding vehicle towards the host vehicle. Furthermore, even if it is determined that the preceding vehicle has moved forward, if it is determined that the host vehicle cannot move forward beyond the determination reference line, the appeal of the notification is reduced.

[0013] Therefore, when the vehicle cannot move forward beyond the determination reference line, the notification level is reduced, thereby reducing the risk of the driver feeling annoyed. Also, when the vehicle can move forward beyond the determination reference line, the notification level is not reduced, so the necessary notification can be made.

[0014] In addition, when a notification is made by a visual notification and an auditory notification, the appeal of the notification may be reduced by not making one of the notifications. The appeal of the visual notification may also be reduced by, for example, making the text smaller. Similarly, the appeal of the auditory notification may also be reduced by, for example, making the volume lower.

[0015] [Mode of the Invention] In one aspect of the present invention, the control unit (driving assistance ECU 10) is configured to determine (S80) that, when the leading vehicle (110) moves forward to reduce the distance between itself and the preceding vehicle (112), the host vehicle (102) cannot move forward beyond the determination reference line (114) even if it is determined that the leading vehicle has moved forward.

[0016] According to the above aspect, when a leading vehicle moves forward to reduce the distance between itself and the preceding vehicle, even if it is determined that the leading vehicle has moved forward, it is determined that the vehicle cannot move forward beyond the judgment reference line, so the appeal of the notification can be reduced.

[0017] In another aspect of the present invention, when the control unit (driving assistance ECU 10) determines that the preceding vehicle (110) has moved forward so as to deviate from the current lane, it determines (S80) that the host vehicle (102) cannot move forward beyond the determination reference line (114) even if it determines that the preceding vehicle has moved forward.

[0018] According to the above aspect, when the preceding vehicle moves forward so as to deviate from the current lane, even if it is determined that the preceding vehicle has moved forward, it is determined that the vehicle cannot move forward beyond the judgment reference line, so the appeal of the notification can be reduced.

[0019] Furthermore, in another aspect of the present invention, the control unit (driving assistance ECU 10) is configured to, when another vehicle moves between the host vehicle (102) and the preceding vehicle (112) and recognizes the other vehicle as a preceding vehicle, and when the preceding vehicle moves forward, determine (S80) that the host vehicle (102) cannot move forward beyond the determination reference line (114) even if it is determined that the preceding vehicle has moved forward.

[0020] According to the above aspect, even if another vehicle moves between the vehicle itself and the preceding vehicle and is recognized as the preceding vehicle, and the preceding vehicle is determined to have moved forward as a result of the other vehicle moving forward, it is determined that the vehicle itself cannot move forward beyond the judgment reference line, thereby reducing the appeal of the notification.

[0021] In the above description, to facilitate understanding of the present invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses for the configurations of the invention corresponding to those embodiments. However, each component of the present invention is not limited to the components of the embodiments corresponding to the names and / or symbols enclosed in parentheses. Other objects, features, and attendant advantages of the present invention will be easily understood from the following description of the embodiments of the present invention, which will be given with reference to the drawings. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram illustrating an embodiment of a preceding vehicle departure notification device according to the present invention; [Figure 2] 4 is a flowchart showing the first half of a preceding vehicle departure notification control routine in the embodiment. [Figure 3] 10 is a flowchart showing the second half of a preceding vehicle departure notification control routine in the embodiment. [Figure 4] FIG. 1A shows a situation in which the vehicle, the preceding vehicle, and the preceding vehicle are stopped, and FIG. 1B shows a situation in which the preceding vehicle moves forward to close the distance between itself and the preceding vehicle. [Figure 5] FIG. 1A shows a situation in which a leading vehicle deviates from its current lane, and FIG. 1B shows a situation in which another vehicle moves in between the vehicle and the leading vehicle from an adjacent lane or from outside the road, becoming the leading vehicle. [Figure 6] FIG. 1A shows a situation in which another vehicle cuts in between the vehicle and the preceding vehicle from an adjacent lane or from outside the road and becomes the preceding vehicle for a while, but does not stay between the vehicle and the preceding vehicle, but moves to the adjacent lane or an area outside the road from which it was before cutting in; and FIG. 1B shows a situation in which another vehicle cuts in between the vehicle and the preceding vehicle from an adjacent lane or from outside the road and becomes the preceding vehicle for a while, but does not stay between the vehicle and the preceding vehicle, but moves to the adjacent lane on the opposite side or an area outside the road. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preceding vehicle departure notification device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0024] As shown in Fig. 1, a preceding vehicle departure notification device 100 according to an embodiment of the present invention is applied to a vehicle 102 and includes a driving assistance ECU 10. The vehicle 102 is an autonomously driven vehicle and includes a drive ECU 20, a brake ECU 30, and a meter ECU 50. The ECU stands for an electronic control unit that includes a microcomputer as its main component. The vehicle 102 will be referred to as the host vehicle 102 as necessary to distinguish it from other vehicles.

[0025] The microcomputer of each ECU includes a CPU, ROM, RAM, read / write non-volatile memory (N / M), and an interface (I / F). The CPU performs various functions by executing instructions (programs, routines) stored in the ROM. Furthermore, these ECUs are interconnected via a Controller Area Network (CAN) 104 to enable data exchange (communication). Therefore, the detected values ​​of sensors (including switches) connected to a specific ECU are transmitted to other ECUs.

[0026] The driving assistance ECU 10 is a central control device that performs driving assistance control such as leading vehicle departure notification control, lane keeping control, etc. In the embodiment, the driving assistance ECU 10 executes leading vehicle departure notification control in cooperation with other ECUs, as will be described in detail later.

[0027] The driving assistance ECU 10 is connected to a camera sensor 12, a radar sensor 14, and a setting operation device 16. The camera sensor 12 and the radar sensor 14 each include a plurality of camera devices and a plurality of radar devices. The camera sensor 12 and the radar sensor 14 function as a target information acquisition device 18 that acquires target information around the vehicle 102, and the target information acquisition device 18 functions as a forward situation detection device that detects the situation ahead of the vehicle.

[0028] Although not shown in the figure, each camera device of the camera sensor 12 includes a camera unit that captures images of the surroundings of the vehicle 102 and a recognition unit that analyzes image data captured by the camera unit to recognize targets such as white lines on the road and other vehicles. The recognition unit supplies information about the recognized targets to the driving assistance ECU 10 at predetermined time intervals.

[0029] Each radar device of the radar sensor 14 includes a radar transmitting / receiving unit and a signal processing unit (not shown). The radar transmitting / receiving unit emits millimeter-wave radio waves (hereinafter referred to as "millimeter waves") and receives millimeter waves reflected by a three-dimensional object (e.g., another vehicle, a bicycle, etc.) within the emission range (i.e., reflected waves). The signal processing unit supplies information indicating the distance between the vehicle and the three-dimensional object, the relative speed between the vehicle and the three-dimensional object, and the relative position (direction) of the three-dimensional object with respect to the vehicle to the driving assistance ECU 10 at predetermined time intervals, based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, and the time from transmitting the millimeter waves to receiving the reflected waves. Note that a LiDAR (Light Detection and Ranging) may be used instead of or in addition to the radar sensor 14.

[0030] The setting operation device 16 is provided in a position that can be operated by the driver, like a steering wheel (not shown in Fig. 1), and is designed to be operated by the driver. Although not shown in Fig. 1, the setting operation device 16 includes a driving assistance switch. As will be described in detail later, when the driving assistance switch is on, the driving assistance ECU 10 activates the preceding vehicle departure warning control. Execute the control.

[0031] The drive ECU 20 is connected to a drive device 22 that accelerates the vehicle 102 by applying a driving force to drive wheels 24. The drive ECU 20 normally controls the drive device 22 so that the driving force generated by the drive device 22 changes in response to the driving operation by the driver, and when it receives a command signal from the driving assistance ECU 10, it controls the drive device 22 based on the command signal.

[0032] The braking ECU 30 is connected to a braking device 32 that applies braking force to wheels 34 to decelerate the vehicle 102. The braking ECU 30 normally controls the braking device so that the braking force generated by the braking device 32 changes in response to the braking operation by the driver, and when it receives a command signal from the driving assistance ECU 10, it controls the braking device 32 based on the command signal to perform automatic braking.

[0033] Therefore, the brake ECU 30 and the brake device 32 work together to function as an automatic braking device 36. When braking force is applied to the wheels by cruise control or the like, a brake lamp (not shown in FIG. 1) is turned on.

[0034] The meter ECU 50 is connected to a touch panel display 52 that displays the status of the leading vehicle departure notification control by the driving assistance ECU 10, a text notification of the leading vehicle departure, and the like, and a speaker 54 that issues an audio warning to notify the leading vehicle departure. The display 52 may be, for example, a multi-information display that displays meters and various information, or may be a display of a navigation device 80 described below. As described below, the display 52 and the speaker 54 issue a visual notification and an audio notification, respectively, of the leading vehicle departure upon receiving a signal from the driving assistance ECU 10. Thus, the display 52 and the speaker 54 function as an alarm device 56 that notifies the driver of the host vehicle that the leading vehicle has started moving.

[0035] The driving operation sensors 60 and the vehicle condition sensors 70 are also connected to the CAN 104. Information detected by the driving operation sensors 60 and the vehicle condition sensors 70 (referred to as sensor information) is transmitted to the CAN 104. The sensor information transmitted to the CAN 104 can be used appropriately in each ECU. Note that the sensor information may be information from a sensor connected to a specific ECU and transmitted to the CAN 104 from that specific ECU.

[0036] The driving operation sensor 60 includes a driving operation amount sensor that detects the amount of accelerator pedal operation, a braking operation amount sensor that detects the master cylinder pressure or the force applied to the brake pedal, a brake switch that detects whether the brake pedal is operated, a steering angle sensor that detects the steering angle, a steering torque sensor that detects the steering torque, etc.

[0037] The vehicle state sensor 70 includes a vehicle speed sensor that detects the vehicle speed V of the vehicle 102, a longitudinal acceleration sensor that detects the longitudinal acceleration of the vehicle, a lateral acceleration sensor that detects the lateral acceleration of the vehicle, and a yaw rate sensor that detects the yaw rate of the vehicle.

[0038] Furthermore, the navigation device 80 is also connected to the CAN 104. The navigation device 80 includes a GPS receiver that detects the position of the vehicle 102, a storage device that stores map information and road information, and a communication device that acquires the latest map information and road information from an external device. In particular, the road information may include information on locations where the vehicle may temporarily stop, such as intersections and pedestrian crossings.

[0039] In this embodiment, the ROM of the driving assistance ECU 10 stores a preceding vehicle departure notification control program corresponding to the flowcharts shown in FIGS.

[0040] <Preceding vehicle departure notification control> Next, the preceding vehicle departure notification control in the embodiment will be described with reference to the flowcharts shown in Figures 2 and 3. The preceding vehicle departure notification control according to the flowcharts shown in Figures 2 and 3 is repeatedly executed at predetermined time intervals by the CPU of the driving assistance ECU 10 when the driving assistance switch is on. The preceding vehicle departure notification method in the embodiment is implemented by executing the preceding vehicle departure notification control according to the flowcharts shown in Figures 2 and 3.

[0041] At the start of the preceding vehicle departure notification control, flag F is initialized to 0. When flag F is 0, it indicates that the appeal of the preceding vehicle departure notification does not need to be reduced, and when flag F is 1, it indicates that the appeal of the preceding vehicle departure notification needs to be reduced.

[0042] First, in step S10, the CPU determines whether the host vehicle 102 and the preceding vehicle 110 are stopped, as shown in FIG. 4(A), based on the information acquired by the target object information acquisition device 18. When a negative determination is made, step S10 is repeatedly executed, and when a positive determination is made, the control proceeds to step S20. Note that the host vehicle may be determined to be stopped when it is determined that the host vehicle is not moving based on the vehicle speed V or the information acquired by the target object information acquisition device 18. Also, when it is determined that the preceding vehicle is not moving based on the information acquired by the target object information acquisition device 18, it may be determined that the preceding vehicle is stopped.

[0043] In step S20, it is determined whether or not there is a stopped preceding vehicle 112, as shown in Figures 4 to 6, based on the information acquired by the target object information acquisition device 18. If a positive determination is made, the control proceeds to step S40, and if a negative determination is made, the control proceeds to step S30. Note that even if there is another vehicle ahead of the preceding vehicle, if the other vehicle is located ahead of the intersection, the other vehicle is not considered to be a preceding vehicle.

[0044] In step S30, control of the preceding vehicle departure notification when there is no preceding vehicle is performed. This control of the preceding vehicle departure notification may be performed in a manner known in the art, and therefore a description thereof will be omitted.

[0045] In step S40, the CPU sets a determination reference line 114 at a position a predetermined distance L from the leading vehicle 112 toward the host vehicle 102, as shown in Figures 4 to 6. The predetermined distance L may be between 0 m and αm (α is a positive constant of, for example, about 2 m).

[0046] In step S50, the CPU determines whether the blinkers (not shown) of the host vehicle 102 and the preceding vehicle 110 are in the same left or right turn direction. This determination is made to confirm whether the preceding vehicle will stop temporarily when turning left or right even after starting to move, and whether the host vehicle will also stop accordingly. If a positive determination is made, the control proceeds to step S100, and if a negative determination is made, the control proceeds to step S60.

[0047] In step S60, the CPU determines whether the traffic light 116 ahead is red or yellow. This determination is made to confirm whether the situation is such that the preceding vehicle will immediately stop even if it starts moving. If a positive determination is made, the control proceeds to step S100, and if a negative determination is made, the control proceeds to step S70.

[0048] In step S70, the CPU determines whether the vehicle speed of the leading vehicle 112 is equal to or less than a reference vehicle speed (a positive constant) based on information acquired by the target information acquisition device 18. This determination is made to confirm whether the leading vehicle is stopped or has just started to move. If a negative determination is made, the control proceeds to step S90, and if a positive determination is made, the control proceeds to step S80.

[0049] In step S80, the CPU determines whether or not the host vehicle 102 can move forward beyond the determination reference line 114, based on the information acquired by the target information acquisition device 18. If a positive determination is made, in step S90, flag F is set to or maintained at 0, and if a negative determination is made, in step S100, flag F is set to or maintained at 1.

[0050] For example, a positive determination is made in step S80 when the host vehicle 102 and the like are in the situations shown in Figures 4 to 6. In the situations shown in Figures 4 to 6, the host vehicle 102 and the leading vehicle 112 are stopped just before intersection C, but the leading vehicle may be in a situation where it has just started to move.

[0051] In FIG. 4(A), the host vehicle 102, the preceding vehicle 110, and the preceding vehicle 112 are stopped.

[0052] In FIG. 4(B), leading vehicle 110 moves forward to close the distance between itself and leading vehicle 112.

[0053] In Figure 5(A), a leading vehicle 110 deviates from the current lane. For example, the leading vehicle moves to a store 118 on the left side of the current lane or to an adjacent lane (not shown) on the left side. Also, a right turn allowed signal 120 is displayed, and the leading vehicle moves to an adjacent lane on the right side of the current lane.

[0054] In FIG. 5(B), another vehicle 122 comes between the vehicle 102 and the preceding vehicle 112 from an adjacent lane or from outside the road, and becomes the preceding vehicle.

[0055] In FIG. 6(A), another vehicle 122 cuts in between the vehicle 102 and the preceding vehicle 112 from an adjacent lane or from outside the road and becomes the preceding vehicle for a time, but does not remain between the vehicle 102 and the preceding vehicle, but moves back to the adjacent lane or area outside the road where it was before cutting in.

[0056] In FIG. 6(B), another vehicle 122 cuts in between the vehicle 102 and the leading vehicle 112 from an adjacent lane or from outside the road and becomes the leading vehicle for a time, but does not remain between the vehicle 102 and the leading vehicle, but moves to the adjacent lane on the opposite side or to an area outside the road.

[0057] In step S110, the CPU determines whether the leading vehicle 110 has moved forward based on the information acquired by the target information acquisition device 18. If a negative determination is made, the control returns to step S50, and if a positive determination is made, the control proceeds to step S120.

[0058] In step S120, the CPU determines whether the host vehicle has moved forward based on the information acquired by the target information acquisition device 18 or the vehicle speed of the host vehicle 102. If a negative determination is made, the control proceeds to step S140, and if a positive determination is made, the control proceeds to step S130.

[0059] In step S130, if the CPU has not notified the driver of the departure of the preceding vehicle, it terminates this control. If the CPU has not notified the driver of the departure of the preceding vehicle, it terminates this control after the notification has been completed.

[0060] In step S140, the CPU determines whether the forward distance of the preceding vehicle 110 is equal to or greater than a reference distance (positive constant) based on the information acquired by the target information acquisition device 18. If a positive determination is made, the control proceeds to step S160, and if a negative determination is made, the control proceeds to step S150.

[0061] In step S150, the CPU determines whether or not a reference time (positive constant) or more has elapsed since it was determined in step S110 that the preceding vehicle 110 started moving forward. If a negative determination is made, the control returns to step S120, and if a positive determination is made, the control proceeds to step S160.

[0062] In step S160, the CPU determines whether flag F is 1, and therefore whether the appeal level of the notification of the departure of the preceding vehicle needs to be reduced. If a negative determination is made, in step S170, a command signal is output to the meter ECU 40, thereby causing notification of the departure of the preceding vehicle to be made by the display 52 and the speaker 54. In contrast, if a positive determination is made, in step S180, a command signal is output to the meter ECU 40, thereby causing notification of the departure of the preceding vehicle to be made by only the display 52.

[0063] As can be seen from the above explanation, when the host vehicle 102 and the preceding vehicle 110 are stopped (S10) and there is a stopped preceding vehicle 112 (S20), the judgment reference line 114 is set at a position a predetermined distance L from the preceding vehicle 112 towards the host vehicle 102 (S40).

[0064] It is determined whether the host vehicle 102 can move forward beyond the determination reference line 114 (S40). If a positive determination is made, the flag F is set to or maintained at 0 (S90), and if a negative determination is made, the flag F is set to or maintained at 1 (S100).

[0065] If it is determined that a notification that the preceding vehicle has started moving is required (S110 to S150), it is determined whether flag F is 1, and therefore whether the appeal level of the notification of the preceding vehicle's departure needs to be reduced (S160). If it is determined that flag F is not 1, the notification of the preceding vehicle's departure is performed by display 52 and speaker 54 (S170). On the other hand, if it is determined that flag F is 1, the notification of the preceding vehicle's departure is performed only by display 52 (S180).

[0066] According to the device and method of the present invention, when there is a leading vehicle 110 ahead of a stopped host vehicle 102 and there is a further leading vehicle 112 stopped ahead of the leading vehicle, a determination reference line 114 is set at a position a predetermined distance L towards the host vehicle from the further leading vehicle. Furthermore, when it is determined that the leading vehicle 110 has moved forward but it is determined that the host vehicle 102 cannot move forward beyond the determination reference line 114, no audio notification is made, thereby reducing the appeal of the notification (S80, S100, S160, S180).

[0067] Therefore, when the vehicle cannot move forward beyond the determination reference line, the notification level is reduced, thereby reducing the risk of the driver feeling annoyed. Also, when the vehicle can move forward beyond the determination reference line, the notification level is not reduced, so the necessary notification can be made.

[0068] Furthermore, according to the device and method of the present invention, when the leading vehicle 110 moves forward to reduce the inter-vehicle distance with the preceding vehicle 112, even if it is determined that the leading vehicle has moved forward, it is determined that the host vehicle 102 cannot move forward beyond the determination reference line 114 (S80). Therefore, the appeal of the notification can be reduced (S180).

[0069] Furthermore, according to the device and method of the present invention, when the preceding vehicle 110 moves forward so as to deviate from the current lane, even if it is determined that the preceding vehicle has moved forward, it is determined that the host vehicle 102 cannot move forward beyond the determination reference line 114 (S80). Therefore, the appeal of the notification can be reduced (S180).

[0070] Furthermore, according to the device and method of the present invention, even if the other vehicle 110 moves between the host vehicle 102 and the preceding vehicle 112 and is recognized as a preceding vehicle, and the preceding vehicle moves forward, it is determined that the preceding vehicle has moved forward, but it is determined that the host vehicle 102 cannot move forward beyond the determination reference line 114 (S80). Therefore, the appeal of the notification can be reduced (S180).

[0071] Although the present invention has been described in detail above with reference to specific embodiments, it will be apparent to those skilled in the art that the present invention is not limited to the above-described embodiments, and that various other embodiments are possible within the scope of the present invention.

[0072] For example, in the above embodiment, in step S50, it is determined whether the turn signals of the host vehicle 102 and the preceding vehicle 110 are in the same left-turn or right-turn direction. In step S60, it is determined whether the traffic light 116 ahead is red or yellow. Furthermore, in step S70, it is determined whether the vehicle speed of the preceding vehicle 112 is equal to or lower than the reference vehicle speed. However, at least one of steps S50 to S70 may be omitted.

[0073] In the above embodiment, the notification device 56 is the display 52 and the speaker 54, but the notification device is not limited to these. For example, other notification means such as a flashing lamp or a buzzer may be used as supplementary notification means.

[0074] In the above embodiment, in step S40, a determination reference line 114 is set at a position a predetermined distance L from the leading vehicle 112 toward the host vehicle 102, and in step S80, it is determined whether the host vehicle 102 can move forward beyond the determination reference line 114. However, a determination area may be set in an area from the leading vehicle 112 toward the host vehicle 102, and it may be determined whether the host vehicle 102 can move forward beyond the determination area.

[0075] Furthermore, in the above-described embodiment, in step S170, the display 52 and the speaker 54 notify the driver that the preceding vehicle has started moving, and in step S180, the display 52 only notifies the driver that the preceding vehicle has started moving. That is, the level of appeal of the notification is reduced by one stage. However, the level of appeal of the notification may be reduced by two or more stages depending on, for example, the possibility that the vehicle 102 may not be able to move forward. [Explanation of symbols]

[0076] 10... driving assistance ECU, 12... camera sensor, 14... radar sensor, 18... target information acquisition device, 22... drive device, 32... braking device, 56... alarm device, 100... preceding vehicle departure alarm device, 102... host vehicle, 110... preceding vehicle, 112... preceding vehicle, 114... judgment reference line

Claims

1. A preceding vehicle departure notification device includes a forward situation detection device that detects a situation ahead of a host vehicle, and a control unit that controls a notification device to notify a driver of the host vehicle that the preceding vehicle has started moving when the host vehicle does not start moving even though the preceding vehicle has started moving, The control unit is configured to, when there is a preceding vehicle ahead of the stopped vehicle and there is an even-more preceding vehicle ahead of the preceding vehicle that is also stopped, set a judgment reference line at a position a predetermined distance from the even-more preceding vehicle towards the vehicle itself, and when it determines that the preceding vehicle has moved forward based on the situation ahead of the vehicle detected by the forward situation detection device, but that the vehicle itself cannot move forward beyond the judgment reference line, reduce the appeal of the notification.

2. 2. The preceding vehicle departure notification device according to claim 1, wherein the control unit is configured to determine that the preceding vehicle cannot move forward beyond the determination reference line even if it determines that the preceding vehicle has started moving when the preceding vehicle moves forward to reduce the inter-vehicle distance between the preceding vehicle and the preceding vehicle.

3. 2. The preceding vehicle departure notification device according to claim 1, wherein the control unit is configured to determine that the preceding vehicle cannot move forward beyond the determination reference line even if it determines that the preceding vehicle has started moving forward when the preceding vehicle moves forward so as to deviate from the current lane.

4. 2. The preceding vehicle departure notification device according to claim 1, wherein the control unit is configured to, when another vehicle moves between the subject vehicle and the preceding vehicle and recognizes the other vehicle as the preceding vehicle, and when the preceding vehicle moves forward, determine that the subject vehicle cannot move forward beyond the determination reference line even if it determines that the preceding vehicle has started.

5. A preceding vehicle departure notification method for notifying a driver of a host vehicle that a preceding vehicle has started moving when the host vehicle does not start moving even after the preceding vehicle has started moving, A method for notifying a driver of a preceding vehicle's departure, comprising the steps of: when there is a preceding vehicle ahead of a stopped driver's vehicle and there is an even further preceding vehicle ahead of the preceding vehicle that is also stopped; setting a judgment reference line at a position a predetermined distance from the even further preceding vehicle towards the driver's vehicle; and when it is determined that the preceding vehicle has moved forward but the driver's vehicle cannot move forward beyond the judgment reference line, reducing the appeal of the notification.

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