Driving support device

Abstract

To provide a driving support device improved to allow an own vehicle to perform a lane change to move to a branch road more smoothly than before.SOLUTION: When it is determined that another vehicle traveling in the same direction of an own vehicle exists within a determination area of an adjacent lane set in a rear side part of the own vehicle (S50), a driving support device executes the issue of an alarm to a lane change to the adjacent lane (S60) or automatic steering resisting against the lane change to the adjacent lane (S70, S80) even when a winker on the side of the adjacent lane is being operated (S10, S20). When it is determined that a branch road exists in front of the own vehicle, a winker on the side of the branch road is being operated, and also the adjacent lane on the side of the branch road is congested, a length of the determination area in a lane direction is reduced (S40).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a driving support device that executes control to improve safety during lane changes.

Background Art

[0002] As one of the driving support devices for vehicles such as automobiles, a driving support device that executes control to improve safety during lane changes is known. For example, in Patent Document 1 below, when another vehicle traveling in an adjacent lane in the same direction as the host vehicle is located behind and to the side of the host vehicle, regardless of whether the turn signal is activated, a driving support device configured to issue a lane departure prevention warning or perform automatic steering is described.

[0003] According to this type of driving support device, safety when attempting to change lanes to an adjacent lane can be improved by issuing a warning or performing automatic steering. That is, the driver is made aware that it is dangerous for the host vehicle to change lanes to an adjacent lane, or the host vehicle's lane change to an adjacent lane is suppressed, thereby reducing the risk of collision with another vehicle traveling in the adjacent lane.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] 〔Problems to be Solved by the Invention〕 In a situation where the host vehicle is traveling on a road in another lane, when there is a branch road in front of the host vehicle and the host vehicle attempts to move to the branch road, it may first be necessary to move to an adjacent lane. In such a case, even if the adjacent lane is congested and another vehicle traveling in the adjacent lane is located behind and to the side of the host vehicle, the host vehicle must change lanes to the adjacent lane.

[0006] However, in a conventional driving support device such as the driving support device described in Patent Document 1, since an alarm for preventing lane departure or automatic steering is issued, it is inevitable that the driver feels annoyed by the alarm or the lane change is hindered by the automatic steering.

[0007] A main object of the present invention is to provide a driving support device that executes control for improving safety during lane changes, and is improved so that a lane change for the host vehicle to move to a branch road can be performed more smoothly than in the prior art.

[0008] 〔Means for Solving the Problems and Effects of the Invention〕 According to the present invention, there is provided a driving support device (100) including a surrounding information acquisition device (16) that acquires information around the host vehicle (102), and based on the information around the host vehicle acquired by the surrounding information acquisition device, when it is determined that there is another vehicle (116) traveling in the same direction as the host vehicle within a determination region (112) of an adjacent lane (114) set on the rear side of the host vehicle (S50), even if the turn signal on the side of the adjacent lane is activated (S10, S20), at least one of an alarm for a lane change to the adjacent lane (S60) and automatic steering against a lane change to the adjacent lane (S70, S80) is executed.

[0009] When there is a branch road in front of the host vehicle (S110), the turn signal on the side of the branch road is activated (S130), and it is determined that the adjacent lane on the side of the branch road is congested based on a preset determination criterion (S120, S150), the control device (driving support ECU 10) is configured to reduce the lane direction length (Ld) of the determination region (112) (S170, S40).

[0010] According to the above configuration, when it is determined that there is another vehicle traveling in the same direction as the host vehicle within the determination area, even if the turn signal on the side of the adjacent lane is activated, at least one of the issuance of an alarm against a lane change to the adjacent lane and the automatic steering that resists the lane change to the adjacent lane is executed. Therefore, the driver is made to recognize that it is dangerous for the host vehicle to change lanes to the adjacent lane, or the host vehicle is suppressed from changing lanes to the adjacent lane, thereby reducing the risk of the host vehicle colliding with another vehicle traveling in the adjacent lane. Accordingly, when there is a branch road in front of the host vehicle and the host vehicle attempts to move to the branch road, the safety when the host vehicle attempts to change lanes to the adjacent lane in a situation where it must move to the adjacent lane can be improved.

[0011] Also, when there is a branch road in front of the host vehicle, the turn signal on the side of the branch road is activated, and it is determined that the adjacent lane on the side of the branch road is congested based on a preset determination criterion, the length of the determination area in the lane direction is reduced. Therefore, it becomes difficult to determine that there is another vehicle traveling in the same direction as the host vehicle within the determination area, so it becomes difficult to issue an alarm or execute automatic steering that resists a lane change to the adjacent lane. Accordingly, the risk that the driver feels annoyed by the alarm or the lane change is inhibited by the automatic steering is reduced, so that the lane change for the host vehicle to move to the branch road can be performed more smoothly than in the conventional case.

[0012] In the above description, in order to assist the understanding of the present invention, the names and / or reference signs used in the embodiments are added in parentheses to the configuration of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the components of the embodiments corresponding to the names and / or reference signs added in parentheses. Other objects, other features, and attendant advantages of the present invention will be easily understood from the description of the embodiments of the present invention described with reference to the following drawings.

Brief Description of the Drawings

[0013]

Figure 1

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Mode for Carrying Out the Invention

[0014] The driving support device according to an embodiment of the present invention will be described in detail with reference to the attached drawings below.

[0015] <Configuration> As shown in FIG. 1, the driving support device 100 according to an embodiment of the present invention is applied to a vehicle 102 and includes a driving support ECU 10. The vehicle 102 includes an electric power steering ECU 20, a meter ECU 30, and a steering ECU 40. ECU means an electronic control unit (Electronic Control Unit) having a microcomputer as a main part. In the following description, the vehicle 102 is referred to as the host vehicle 102 as necessary to distinguish it from other vehicles, and the electric power steering is referred to as EPS.

[0016] The microcomputers of each ECU include a CPU, a ROM, a RAM, a rewritable non-volatile memory (N / M), and an interface (I / F), etc. The CPU realizes various functions by executing the instructions (programs, routines) stored in the ROM. Furthermore, these ECUs are connected to each other via a CAN (Controller Area Network) 104 so that data can be exchanged (communication is possible). Therefore, the detection values of the sensors (including switches) connected to a specific ECU are also transmitted to other ECUs.

[0017] The driving support ECU 10 is a central control device that performs driving support controls such as lane departure prevention control and following distance control. In the embodiment, as will be described in detail later, the driving support ECU 10 cooperates with other ECUs to execute safety improvement control during lane change as part of the lane departure prevention control.

[0018] A camera sensor 12 and a radar sensor 14 are connected to the driving support ECU 10. The camera sensor 12 includes four camera sensors that photograph the front, rear, right side, and left side, but is not limited to four. The radar sensor 14 includes five radar sensors that acquire target information of solid objects existing in the front area, the right front area, the left front area, the right rear area, and the left rear area, but is not limited to five. The camera sensor 12 and the radar sensor 14 function as a surrounding information acquisition device 16 that acquires information around the host vehicle 102.

[0019] Each camera sensor of the camera sensor 12, although not shown in the figure, includes a camera unit that photographs the surroundings of the vehicle 102, and a recognition unit that analyzes the image data obtained by the camera unit to recognize targets such as the white line of the road and other vehicles. The recognition unit supplies information about the recognized targets to the driving support ECU 10 every time a predetermined time elapses. Note that LiDAR (Light Detection And Ranging) may be used instead of the camera sensor 12.

[0020] Each radar sensor of the radar sensor 14 includes a radar transceiver and a signal processing unit (not shown). The radar transceiver emits radio waves in the millimeter wave band (hereinafter referred to as "millimeter waves"), and receives the millimeter waves (i.e., reflected waves) reflected by a three-dimensional object (e.g., another vehicle, a bicycle, a guardrail, etc.) existing within the radiation range. The signal processing unit acquires information representing the distance between the host vehicle and the three-dimensional object, the relative speed between the host vehicle and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the host vehicle, etc. based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, the time from transmitting the millimeter waves to receiving the reflected waves, etc., and supplies the information to the driving support ECU 10 every time a predetermined time elapses.

[0021] Furthermore, a setting operator 18 is connected to the driving support ECU 10, and the setting operator 18 is provided at a position operated by the driver. Although not shown in FIG. 1, the setting operator 18 includes a lane departure prevention control switch, and the driving support ECU 10 executes lane departure prevention control when the lane departure prevention control switch is on.

[0022] An EPS device 22 is connected to the EPS·ECU 20. The EPS·ECU 20 controls the EPS device 22 in a known manner in the art based on the steering torque Ts and the vehicle speed V detected by a driving operation sensor 50 and a vehicle state sensor 60 described later, thereby controlling the steering assist torque and reducing the driver's steering burden. In addition, the EPS·ECU 20 can steer the steered wheels as needed by controlling the EPS device 22. Therefore, the EPS·ECU 20 and the EPS device 22 function as a steering device that automatically steers the steered wheels as needed.

[0023] The meter ECU 30 is connected to a display 32, blind spot monitors (BSMs) 34R and 34L, turn signal lamps 36R and 36L, and a buzzer 38 that emits an alarm sound. The display 32 may be, for example, a head-up display or a multi-information display on which meters and various types of information are displayed, or may be the display of the navigation device 70 described later. The blind spot monitors 34R and 34L are provided on the right and left door mirrors, respectively, so as to be visible from the driver's seat. When a following vehicle approaches rapidly, the meter ECU 30 displays that the following vehicle is approaching on the corresponding side's blind spot monitor and activates the buzzer 38 to issue an alarm.

[0024] The steering ECU 40 is connected to a turn signal lever 42 provided on a steering column (not shown). When the turn signal lever 42 tilts in the vertical direction corresponding to the right turn direction and the left turn direction, a signal indicating this is supplied to the meter ECU 30, and thereby the right and left turn signal lamps 36R and 36L blink.

[0025] The driving operation sensor 50 and the vehicle state sensor 60 are connected to the CAN 104. Information (referred to as sensor information) detected by the driving operation sensor 50 and the vehicle state sensor 60 is transmitted to the CAN 104. The sensor information transmitted to the CAN 104 can be appropriately used in each ECU. Note that the sensor information may be information of a sensor connected to a specific ECU and transmitted from the specific ECU to the CAN 104.

[0026] The driving operation sensor 50 includes a drive operation amount sensor that detects the operation amount of the accelerator pedal, a braking operation amount sensor that detects the master cylinder pressure or the stepping force on the brake pedal, and a brake switch that detects the presence or absence of the operation of the brake pedal. Further, the driving operation sensor 50 includes a steering angle sensor that detects the steering angle θ, a steering torque sensor that detects the steering torque Ts, and a shift position sensor that detects the shift position of the transmission.

[0027] The vehicle state sensor 60 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.

[0028] The navigation device 70 is also connected to the CAN 104. The navigation device 70 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 information of the map information and road information from the outside. The road information includes information such as branch points and intersections of general roads, and information such as interchanges, junctions, service areas, and parking areas of motor vehicle-only roads such as highways. The navigation device 80 outputs road information to the driving support ECU 10 in addition to information such as the position and traveling direction of the vehicle on the map.

[0029] When the lane departure prevention switch is set to on by the operation of the setting operation device 18 by the driver, the driving support ECU 10 executes lane departure prevention control based on the information around the vehicle 102 detected by the surrounding information acquisition device 16. In particular, in the embodiment, as part of the lane departure prevention control, safety improvement control during lane change is executed according to the flowchart shown in FIG. 2, and control of the correction coefficient is executed according to the flowchart shown in FIG. 3.

[0030] <Safety improvement control routine during lane change in the embodiment> Next, the safety improvement control routine during lane change in the embodiment will be described with reference to the flowchart shown in FIG. 2. The safety improvement control during lane change according to the flowchart shown in FIG. 2 is executed by the CPU of the driving support ECU 10 when the lane departure prevention switch (not shown in FIG. 1) of the setting operation device 18 is on.

[0031] First, in step S10, the CPU determines whether the turn signal is activated when attempting to change lanes, that is, determines whether the turn signal lamp 36R or 36L is flashing due to the tilting of the turn signal lever 42. When the CPU makes a negative determination, it terminates this control once. When it makes an affirmative determination, it advances this control to step S20.

[0032] In step S20, the CPU determines whether there is an adjacent lane for the host vehicle 102 to travel in the same direction as the side where the turn signal is activated. When the CPU makes a negative determination, that is, when it determines that there is no adjacent lane on the side where the turn signal is activated or the adjacent lane is on the side opposite to the side where the turn signal is activated, it terminates this control once. When it makes an affirmative determination, it advances this control to step S30.

[0033] In step S30, the CPU calculates the length Ld of the determination area set at the rear side of the host vehicle 102 for the adjacent lane whose existence was confirmed in step S20. FIG. 4 shows the determination area 112 in a situation where the left turn signal lamp 36L of the host vehicle 102 traveling in the lane 110 is flashing. The determination area 112 is set in the adjacent lane 114 on the left side of the host vehicle 102. The front end 112F of the determination area 112 is, for example, the position of the axle of the rear wheel (not shown) of the host vehicle 102, and the length Ld is the length along the adjacent lane 114 from the front end 112F to the rear end 112R.

[0034] The length Ld is calculated so as to increase as the distance in the direction perpendicular to the lane between the host vehicle 102 and another vehicle 116 traveling in the adjacent lane 114 becomes smaller. Also, with the relative speed of the other vehicle 116 with respect to the host vehicle 102 being Vr and the distance in the direction along the lane between the host vehicle 102 and the other vehicle 116 being Dr, it is calculated so as to increase as the relative speed Vr is positive and Dr / Vr is smaller. Note that the width of the determination area 112 is the width of the adjacent lane 114.

[0035] In step S40, the CPU corrects the length Ld of the determination area 112 by multiplying it by a correction coefficient Ka controlled according to the flowchart shown in FIG. 3 and the length Ld of the determination area 112 calculated in step S30.

[0036] In step S50, the CPU determines whether there is another vehicle approaching the host vehicle in the determination area 112 based on the information around the host vehicle 102 acquired by the surrounding information acquisition device 16. When the CPU makes a negative determination, it temporarily ends this control. When the CPU makes an affirmative determination, it advances this control to step S60.

[0037] In step S60, the CPU outputs a command signal to the meter ECU 30, causing the display 32 and the blind spot monitor 34R or 34L to display a visual warning indicating that an approaching other vehicle is at the rear side and that a lane change is dangerous. Also, the CPU sounds the buzzer 38 to issue an auditory warning.

[0038] In step S70, the CPU determines whether a steering operation is performed by the driver to move the host vehicle 102 toward the adjacent lane 114. When the CPU makes a negative determination, it temporarily ends this control. When the CPU makes an affirmative determination, it advances this control to step S80.

[0039] In step S80, the CPU outputs a command signal to the EPS·ECU 20 so that automatic steering in the direction opposite to the steering operation direction by the driver is performed, thereby executing automatic steering against the lane change of the host vehicle 102.

[0040] According to the above safety improvement control routine during lane change, when the turn signal is activated (S10), there is an adjacent lane on the side where the turn signal is activated (S20), and it is determined that there is another vehicle approaching the host vehicle in the determination area 112 (S20), an alarm is issued (S60) and automatic steering against the lane change (S80) is performed.

[0041] Therefore, the driver is made to recognize that it is dangerous for the host vehicle 102 to change lanes to an adjacent lane, and the host vehicle is suppressed from changing lanes to the adjacent lane, thereby reducing the risk of the host vehicle colliding with other vehicles traveling in the adjacent lane. Accordingly, as will be described later, when there is a branch road ahead of the host vehicle and the host vehicle attempts to move to the branch road, the safety when the host vehicle attempts to change lanes to the adjacent lane can be improved in a situation where it must move to the adjacent lane.

[0042] <Control Routine for Correction Coefficient in Embodiment> Next, the control routine for the correction coefficient in the embodiment will be described with reference to the flowchart shown in FIG. 3. The control of the correction coefficient according to the flowchart shown in FIG. 3 is executed by the CPU of the driving support ECU 10 when a lane departure prevention switch (not shown in FIG. 1) of the setting operation device 18 is on.

[0043] First, in step S110, the CPU determines whether there is a branch road ahead of the host vehicle 102 based on the information of the road sign photographed and recognized by the camera sensor 12 and / or the information from the navigation device 70. When the CPU makes a negative determination, this control proceeds to step S160, and when the CPU makes an affirmative determination, this control proceeds to step S120.

[0044] In step S120, the CPU determines whether there is an adjacent lane on the same side as the side where the branch road is located with respect to the lane in which the host vehicle 102 is traveling. When the CPU makes a negative determination, this control proceeds to step S160, and when the CPU makes an affirmative determination, this control proceeds to step S130.

[0045] FIG. 5 shows a situation where there is a branch road 120 ahead of the host vehicle 102 traveling on a two-lane exclusive road for automobiles. In particular, (A) shows the case where the host vehicle 102 is traveling in the right lane 122, and (B) shows the case where the host vehicle 102 is traveling in the left lane 124. The determination in step S120 is an affirmative determination in the case of (A), but a negative determination in the case of (B).

[0046] FIG. 6 shows a situation where there is a branch road 120 in front of the right side of the host vehicle 102 traveling on a two-lane exclusive motorway. In particular, (C) is the case where the host vehicle 102 travels in the right lane 122, and (D) is the case where the host vehicle 102 travels in the left lane 124. The determination in step S120 is a negative determination in the case of (C), but a positive determination in the case of (D).

[0047] In step S130, the CPU determines whether or not the turn signal on the same side as the side where the branch road is present is operating. When the CPU makes a negative determination, it advances this control to step S160, and when it makes a positive determination, it advances this control to step S140.

[0048] In step S140, the CPU calculates the average inter-vehicle time Thwa for other vehicles traveling in a preset range of the adjacent lane determined to exist in step S120.

[0049] For example, FIG. 7 shows a situation where there are four other vehicles 134 to 140 in the range from a position Lf ahead of the host vehicle 102 to a position Lr behind the host vehicle among other vehicles traveling in the adjacent lane 132 on the left side of the lane 130 in which the host vehicle 102 travels. The average value Thw13 of the inter-vehicle times Thw1 to Thw3 between the vehicles adjacent to the front and rear of the other vehicles 134 to 140 is calculated, and further, for example, the average value of the average value Thw13 in the past one second is calculated as the average inter-vehicle time Thwa. Note that the calculation of the average inter-vehicle time Thwa is not limited to the above-described method, and may be performed by any method known in the art.

[0050] In step S150, the CPU determines whether or not the adjacent lane is congested by determining whether or not the average inter-vehicle time Thwa is less than or equal to the reference value Thwac. When the CPU makes a negative determination, it sets the correction coefficient Ka to 1 in step S160, and when it makes a positive determination, it sets the correction coefficient Ka to the reduced correction coefficient Kac in step S170.

[0051] Note that the reference value Thwac may be a positive constant, may be the average vehicle speed of other vehicles traveling in the adjacent lane, or may be variably set according to the speed limit of the road on which the host vehicle 102 travels, the width of the lane, etc. Further, the reduced correction coefficient Kac may be a positive constant greater than 0 and less than 1, for example 0.5, and may be variably set according to the average inter-vehicle time Thwa so that it becomes smaller as the average inter-vehicle time Thwa becomes smaller.

[0052] According to the control routine of the above correction coefficient, when there is a branch road in front of the host vehicle 102 (S110), there is an adjacent lane on the same side as the side where the branch road is located (S120), the turn signal on the same side as the side where the branch road is located is activated (S130), and it is determined that the adjacent lane is congested (S150), the correction coefficient Ka is set to the reduced correction coefficient Kac (S170).

[0053] Therefore, by reducing the length Ld of the determination area 112 (S40), it becomes difficult to determine that there is another vehicle traveling in the same direction as the host vehicle within the determination area, so it becomes difficult to issue an alarm and execute automatic steering against lane change to the adjacent lane. Accordingly, the possibility that the driver feels annoyed by the alarm or the lane change is inhibited by the automatic steering is reduced, so that the lane change for the host vehicle to move to the branch road can be performed more smoothly than in the conventional case.

[0054] Although the present invention has been described in detail with respect to specific embodiments above, it is obvious to those skilled in the art that the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention.

[0055] For example, in the above-described embodiment, in step S30, the length Ld of the determination region is calculated such that it becomes larger as the distance in the direction perpendicular to the lane between the host vehicle 102 and the other vehicle 116 traveling in the adjacent lane 114 becomes smaller. Also, with the relative speed of the other vehicle 116 with respect to the host vehicle 102 being Vr and the distance in the direction along the lane between the host vehicle 102 and the other vehicle 116 being Dr, it is calculated such that it becomes larger as the relative speed Vr is positive and Dr / Vr is smaller. However, at least one of the former and the latter variable settings may be omitted.

[0056] Also, in the above-described embodiment, the reduced correction coefficient Kac set in step S170 is a positive constant greater than 0 and less than 1. However, the reduced correction coefficient Kac may be 0. In that case, since the size of the determination region 112 becomes 0, the determination in step S50 becomes a negative determination. Therefore, the issuance of an alarm and the automatic steering against a lane change to the adjacent lane are not executed. Thus, it is possible to prevent the driver from being bothered by the alarm or the lane change being inhibited by the automatic steering.

[0057] Also, in the above-described embodiment, when the turn signal is activated (S10), there is an adjacent lane on the side where the turn signal is activated (S20), and it is determined that there is an other vehicle approaching the host vehicle in the determination region 112 (S20), an alarm is issued (S60) and automatic steering against a lane change (S80) is performed. However, either the issuance of the alarm or the automatic steering against a lane change may be omitted.

Explanation of Signs

[0058] 10… Driving support ECU, 12… Camera sensor, 14… Radar sensor, 16… Surrounding information acquisition device, 20… EPS·ECU, 22… EPS device, 30… Meter ECU, 32… Display, 34R, 34L… Blind spot monitor, 36R, 36L… Turn signal lamp, 42… Turn signal lever, 50…… Driving operation sensor, 60… Vehicle state sensor, 102… Host vehicle, 112… Determination region, 114… Adjacent lane, 116… Other vehicle

Claims

【Claim 1】 A driving support device including: a surrounding information acquisition device that acquires information around the host vehicle; and a control device configured to, when it is determined that there is another vehicle traveling in the same direction as the host vehicle within a determination area of an adjacent lane set on the rear side of the host vehicle based on the information around the host vehicle acquired by the surrounding information acquisition device, execute at least one of issuing an alarm against a lane change to the adjacent lane and automatic steering against the lane change to the adjacent lane even if a turn signal on the side of the adjacent lane is activated. The driving support device, wherein the control device is configured to reduce the length in the lane direction of the determination area when there is a branch road in front of the host vehicle, a turn signal on the side of the branch road is activated, and it is determined that the adjacent lane on the side of the branch road is congested based on a preset determination criterion.

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