Lane deviation prevention device, lane deviation prevention method, and program for the same

Abstract

To provide a lane deviation prevention device, a lane deviation prevention method, and a program for the same which can prevent obstruction of progress of a rear approaching vehicle.SOLUTION: A lane deviation prevention device comprises a control unit (10) configured to execute a lane deviation preventing action that automatically applies a force in a direction to avoid deviation from an own lane to an own vehicle when the own vehicle (HV) has a possibility of the lane departure from the own lane, and cancel the execution of the lane deviation preventing action when a turn signal of the own vehicle blinks. The control unit allows the execution of the lane deviation preventing action without cancellation, when detecting a rear approaching vehicle positioned in the own lane and approaching the own vehicle from behind the own vehicle, even when the turn signal of the own vehicle blinks.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lane departure prevention device, a lane departure prevention method, and a program thereof that execute lane departure prevention control for preventing (restraining) a host vehicle from deviating from its own lane, which is the lane in which the host vehicle is traveling.

Background Art

[0002] Conventional lane departure prevention devices issue an alarm for notifying a driver to that effect when the possibility of lane departure is detected. On the other hand, when the turn signal (direction indicator) of the host vehicle is blinking, even when the possibility of lane departure is detected, the alarm is not issued. However, the above conventional device issues the alarm when the front vehicle is about to overtake another vehicle even when the turn signal of the host vehicle is blinking (see Patent Document 1). Thereby, it is possible to prevent the occurrence of a situation in which the host vehicle starts an overtaking operation when the front vehicle is about to overtake yet another vehicle (i.e., double overtaking). Further, conventionally, in order to prevent lane departure, there is also known a device that executes a lane departure prevention operation of changing the steering angle of a vehicle in a direction to prevent lane departure when the possibility of lane departure is detected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] However, the conventional device does not consider at all how to perform lane departure prevention control for a vehicle (hereinafter also referred to as a "rear approaching vehicle") that is located within the lane in which the host vehicle is traveling (hereinafter also referred to as the "host lane") and approaches the host vehicle from behind the host vehicle. For this reason, as shown in (B) of FIG. 2, even when the rear approaching vehicle RV is about to change lanes to a lane adjacent to the host lane (hereinafter referred to as the "adjacent lane") to overtake the host vehicle HV, when the driver of the host vehicle tries to change lanes of the host vehicle to the same adjacent lane while blinking the turn signal of the host vehicle, the conventional device does not execute a deviation suppression support operation (an alarm generation operation and a lane departure prevention operation by steering) for preventing the host vehicle from deviating from the host lane. As a result, there is a problem that the host vehicle HV may approach the rear approaching vehicle RV excessively and hinder the progress of the rear approaching vehicle RV.

[0005] The present invention has been made to solve such problems. That is, one of the objects of the present invention is to provide a lane departure prevention device, a lane departure prevention method, and a program thereof that can prevent the progress of a rear approaching vehicle as described above from being hindered.

[0006] One aspect of the lane departure prevention device according to the present invention includes a control unit configured to execute at least one of an alarm generation operation for generating an alarm to the driver of the host vehicle and a lane departure prevention operation for automatically applying a force in a direction to avoid deviation of the host vehicle from the host lane as a deviation suppression support operation when there is a possibility that the host vehicle deviates from the host lane (S335, S385, S735, S745, S750), and cancel the execution of the lane departure prevention operation when the turn signal of the host vehicle is in a blinking state (S320 to S330, S405, S420, S370 to S380, S435, S450, S920, S720, S725).

[0007] Furthermore, the control unit When there is a rear approaching vehicle that is located within the own lane and approaches the own vehicle from behind the own vehicle (when detected) (S425, S455, S950), even when the turn signal of the own vehicle is in a blinking state, the execution of the deviation suppression support operation is allowed without being canceled (S410, S440, S960).

[0008] According to this aspect, when there is a rear approaching vehicle, the execution of the deviation suppression support operation is not canceled. Therefore, when the rear approaching vehicle attempts to change lanes and overtake the own vehicle, the own vehicle is more likely to be maintained within the own lane. Thus, the possibility of preventing the own vehicle and the rear approaching vehicle from approaching excessively can be increased.

[0009] In one aspect of the lane departure prevention device according to the present invention, the control unit, is configured to execute the lane departure prevention operation as the deviation suppression support operation, and determines whether the rear approaching vehicle is about to change lanes to the right adjacent lane adjacent to the right side of the own lane (S430). When it is determined that the rear approaching vehicle is about to change lanes to the right adjacent lane, even when the turn signal of the own vehicle is in a blinking state, at least the execution of the lane departure prevention operation for avoiding the deviation of the own vehicle to the right adjacent lane side is allowed without being canceled (S410).

[0010] According to this, in a situation where the rear approaching vehicle attempts to chase the own vehicle after changing lanes to the right adjacent lane, when the own vehicle attempts to change lanes to the right adjacent lane, the execution of the "lane departure prevention operation for avoiding the deviation of the own vehicle to the right adjacent lane side" is not canceled. Thus, the possibility of preventing the own vehicle and the rear approaching vehicle from approaching excessively in the right adjacent lane can be increased.

[0011] In one aspect of the lane departure prevention device according to the present invention, The control unit is configured to execute the lane departure prevention operation as the deviation suppression support operation, and determine whether the approaching vehicle behind is about to change lanes to the left adjacent lane adjacent to the left side of the own lane (S460). When it is determined that the approaching vehicle behind is about to change lanes to the left adjacent lane, even when the turn signal of the own vehicle is blinking, at least the execution of the lane departure prevention operation for avoiding the deviation of the own vehicle to the left adjacent lane side is allowed without canceling (S440).

[0012] According to this, in a situation where the approaching vehicle behind tries to chase the own vehicle after changing lanes to the left adjacent lane, when the own vehicle tries to change lanes to the left adjacent lane, the execution of the "lane departure prevention operation for avoiding the deviation of the own vehicle to the left adjacent lane side" is not canceled. Therefore, it is possible to increase the possibility of preventing the own vehicle and the approaching vehicle behind from approaching too closely in the left adjacent lane.

[0013] In one aspect of the lane departure prevention device according to the present invention, the control unit is configured to execute the lane departure prevention operation as the deviation suppression support operation, and when the approaching vehicle behind exists (is detected), even when the turn signal of the own vehicle is blinking, at least the execution of the lane departure prevention operation for the deviation to the overtaking lane side with respect to the own lane is allowed without canceling.

[0014] The approaching vehicle behind often changes lanes from the own lane to the overtaking lane and then overtakes the own vehicle. According to the above aspect, in a situation where the turn signal of the own vehicle is blinking, at least the own vehicle can be prevented from deviating to the overtaking lane side. Therefore, it is possible to increase the possibility of preventing the own vehicle and the approaching vehicle behind from approaching too closely in the overtaking lane.

[0015] In one aspect of the lane departure prevention device according to the present invention, the control unit is configured to: execute the lane departure prevention operation as the departure suppression support operation (S335, S385), and when the right turn signal of the host vehicle is blinking, cancel the execution of the right departure prevention operation among the lane departure prevention operations for suppressing the host vehicle from departing to the right from the host lane (S405, S420), determine whether the approaching vehicle behind is about to change lanes to the right adjacent lane adjacent to the right side of the host lane (S430), and when it is determined that the approaching vehicle behind is about to change lanes to the right adjacent lane, even when the right turn signal of the host vehicle is blinking, at least the execution of the right departure prevention operation is configured not to be canceled and to be allowed (S410), when the left turn signal of the host vehicle is blinking, cancel the execution of the left departure prevention operation among the lane departure prevention operations for suppressing the host vehicle from departing to the left from the host lane (S435, S450), determine whether the approaching vehicle behind is about to change lanes to the left adjacent lane adjacent to the left side of the host lane (S460), and when it is determined that the approaching vehicle behind is about to change lanes to the left adjacent lane, even when the left turn signal of the host vehicle is blinking, at least the execution of the left departure prevention operation is configured not to be canceled and to be allowed (S440).

[0016] According to this, when the host vehicle and the approaching vehicle behind are both about to change lanes to the adjacent lane on the same side, the execution of the lane departure prevention operation for avoiding the host vehicle from departing from the host lane to the lane side where the lane change is about to be made is not canceled. Therefore, the possibility of preventing the host vehicle and the approaching vehicle behind from approaching each other excessively in the adjacent lane can be increased.

[0017] In one aspect of the lane departure prevention device according to the present invention, the control unit, when the right turn signal of the host vehicle is in a blinking state (S405), and only when there is a right adjacent lane which is a lane adjacent to the host lane in which the host vehicle can change lanes to the right (S415), it is configured to cancel the execution of the right departure prevention operation (S420), when the left turn signal of the host vehicle is in a blinking state (S435), and only when there is a left adjacent lane which is a lane adjacent to the host lane in which the host vehicle can change lanes to the left (S445), it is configured to cancel the execution of the left departure prevention operation (S450).

[0018] According to this, it is possible to avoid the host vehicle from departing in a direction where there is no lane in which the host vehicle can change lanes from the host lane.

[0019] In the above description, for the purpose of assisting the understanding of the present invention, the names and / or symbols used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the embodiments defined by the above names and / or symbols. The present invention also extends to a lane departure prevention method and its program.

Brief Description of the Drawings

[0020]

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Mode for Carrying Out the Invention

[0021] The "lane departure prevention (suppression) device DS (hereinafter referred to as the 'device DS')" according to the embodiment of the present invention includes the components shown in FIG. 1 and is applied (mounted) to the host vehicle HV. The host vehicle HV may be any of a vehicle having an internal combustion engine as a power source, a vehicle having an electric motor as a power source (i.e., an electric vehicle), and a hybrid vehicle.

[0022] In this specification, "ECU" is an electronic control device (control unit) including a microcomputer including a CPU (processor), ROM, RAM, a writable non-volatile memory for data, and an interface. The ECU is also referred to as a controller or a computer. A plurality of ECUs shown in FIG. 1 are connected to be able to exchange information with each other through a CAN (Controller Area Network). Some or all of these plurality of ECUs may be integrated into one ECU.

[0023] The driving support (lane departure prevention) ECU 10 uses the components described in FIG. 1 to execute the lane departure prevention control described later. Note that the functions of the driving support ECU 10 may be realized by a plurality of ECUs. The driving support ECU 10 is connected to the following components (camera, sensor, switch, and device, etc.) and transmits and receives information or signals with them.

[0024] The front camera 20 captures the scene in front of the host vehicle HV every time a predetermined time elapses, and acquires front image data. The driving support ECU 10 recognizes the boundary lines of the lanes on the road on which the host vehicle HV is traveling based on the front image data. The boundary lines include lane dividing lines (lane markers, for example, white lines) and objects that define the lanes (for example, guardrails, walls, curbs, etc.). Further, the driving support ECU 10 can acquire the position in the lane width direction of the host vehicle HV with respect to the boundary line (the distance from the boundary line to the host vehicle HV), the speed in the lane width direction of the host vehicle HV, and the angle formed by the boundary line and the traveling direction of the host vehicle HV, etc. based on the front image data.

[0025] The rear camera 21 captures the scene behind the host vehicle HV every time a predetermined time elapses, and acquires rear image data. The driving support ECU 10 can acquire the "distance from the host vehicle HV and the position in the lane width direction in the host lane" of a vehicle (i.e., a rear approaching vehicle) that is located within the lane in which the host vehicle HV is traveling (i.e., the host lane) and approaches the host vehicle HV from behind the host vehicle HV based on the rear image data. Therefore, the driving support ECU 10 can acquire the "speed and acceleration" in the lane width direction of the rear approaching vehicle based on the temporal change of the position in the lane width direction of the rear approaching vehicle.

[0026] The right rear radar 22 acquires target information (the distance from the host vehicle HV to the target, the relative speed of the target with respect to the host vehicle, and the azimuth of the target) about targets located at the right rear and rear of the host vehicle HV using radio waves in the millimeter wave band. The left rear radar 23 acquires target information about targets located at the left rear and rear of the host vehicle HV using radio waves in the millimeter wave band. The driving support ECU 10 can acquire the "distance, relative speed, azimuth, etc. from the host vehicle HV" of a vehicle located within the host lane and behind the host vehicle based on the information from the right rear radar 22 and the left rear radar 23 (hereinafter referred to as "rear radar information"). Note that the rear approaching vehicle is another vehicle that is located within the host lane and behind the host vehicle and has a relative speed approaching the host vehicle HV that is equal to or higher than the threshold speed.

[0027] The driving support ECU 10 generates fusion target information by integrating the information obtained based on the rear image data and the rear radar information.

[0028] The vehicle speed sensor 24 outputs a signal indicating the speed of the host vehicle HV (i.e., the host vehicle speed) Vh. The yaw rate sensor 25 outputs a signal indicating the yaw rate Yr of the host vehicle HV. The steering angle sensor 26 outputs a signal indicating the steering angle Sa of the host vehicle HV. The steering torque sensor 27 outputs a signal indicating the steering torque Tq of the host vehicle HV. The acceleration sensor 28 outputs a signal indicating the longitudinal acceleration and the lateral acceleration of the host vehicle HV.

[0029] The turn signal switch 30 outputs a signal to the turn signal control device 31 to set the right turn signal 32R to the on state (flashing state) when the direction indicator lever operated by the driver of the host vehicle HV is in the first position, and outputs a signal to the turn signal control device 31 to set the left turn signal 32L to the on state (flashing state) when the direction indicator lever is in the second position. The turn signal control device 31 blinks either the right turn signal 32R or the left turn signal 32L based on the signal from the turn signal switch 30.

[0030] The steering motor 40 drives the steering mechanism 41 of the host vehicle HV in response to an instruction from the driving support ECU 10 to change the steering angle of the host vehicle HV. Therefore, when there is a possibility that the host vehicle HV may deviate from its own lane, the driving support ECU 10 can apply a force to the host vehicle HV in the direction of the center (center line) of its own lane by changing the steering angle. Note that the driving support ECU 10 may apply a force to the host vehicle HV in the direction of the center (center line) of its own lane by applying a difference in the driving force between the left driving wheel and the right driving wheel or by applying a difference in the braking force between the left wheel and the right wheel.

[0031] The display device 51 displays a warning mark indicating that the host vehicle HV may deviate from its own lane or has deviated from its own lane to the driver of the host vehicle HV in accordance with an instruction from the driving support ECU 10.

[0032] The speaker 52 generates a warning sound indicating that the host vehicle HV may deviate from its own lane or has deviated from its own lane to the driver of the host vehicle HV in accordance with an instruction from the driving support ECU 10.

[0033] The vehicle exterior communication device 60 communicates (for example, road-vehicle communication and vehicle-vehicle communication) with devices external to the host vehicle HV (for example, roadside units and communication devices of other vehicles) and acquires various information from the external devices.

[0034] The navigation ECU 70 is connected to a GPS receiver 71, a map database 72, and a display touch panel 73 that displays touch buttons. The navigation ECU 70 estimates the current position of the host vehicle HV based on the GPS signal received by the GPS receiver 71, and from the current position of the host vehicle HV and the map information stored in the map database 72, it can acquire information about the lanes of the road on which the host vehicle HV is traveling at the current time (how many lanes there are on one side) and information about which lane the host vehicle HV is traveling in.

[0035] (Outline of operation) (Lane departure prevention (suppression) control) As shown in Fig. 2(A), the driving support ECU 10 recognizes the "left boundary line LLM and right boundary line RLM" that demarcate the own lane HL based on the forward camera information. Next, the driving support ECU 10 sets a left outer reference line LOT obtained by shifting the center line LC of the left boundary line LLM by a distance D1L to the left side (outer side) in the lane width direction, and a left inner reference line LIN obtained by shifting the center line LC by a distance D2L to the right side (inner side) in the lane width direction. Similarly, the driving support ECU 10 sets a right outer reference line ROT obtained by shifting the center line RC of the right boundary line RLM by a distance D1R to the right side (outer side) in the lane width direction, and a right inner reference line RIN obtained by shifting the center line RC by a distance D2R to the left side (inner side) in the lane width direction.

[0036] When any of the following conditions CL1 and CL2 is satisfied, the driving support ECU 10 determines that the left departure prevention operation start condition is satisfied, and automatically steers the steering angle to the right so that the host vehicle HV does not deviate from the left boundary line LLM to the outside of the own lane HL (so that the host vehicle HV returns to the center in the lane width direction of the own lane HL). This automatic steering is an operation of "automatically applying a force in a direction to avoid deviation from the own lane" to the host vehicle, and is referred to as a lane departure prevention operation. Further, when executing the lane departure prevention operation, the driving support ECU 10 executes an alarm generation operation for generating an alarm to the driver of the host vehicle. The lane departure prevention operation and the alarm generation operation are also referred to as a deviation suppression support operation.

[0037] <<Left Departure Prevention Operation Start Condition>> (Condition CL1) It is estimated that the left front end of the host vehicle HV reaches the left outer reference line LOT after a certain time T. The driving support ECU 10 predicts the position of the host vehicle HV in the lane width direction after a certain time T based on the distance DL from the center line LC of the left boundary line LLM in the lane width direction of the host vehicle HV at the current time, the leftward speed (left lateral speed) of the host vehicle HV in the lane width direction, and the leftward acceleration (left lateral acceleration) of the host vehicle HV in the lane width direction, and determines whether Condition CL1 is satisfied based on that position. (Condition CL2) At the current time, the left front end of the host vehicle HV has reached the left inner reference line LIN.

[0038] When either of the following conditions CR1 and CR2 is satisfied, the driving support ECU 10 determines that the right deviation prevention operation start condition is satisfied, and automatically steers the steering angle to the left so that the host vehicle HV does not deviate outside the own lane HL from the right boundary line RLM (so that the host vehicle HV returns to the center in the lane width direction of the own lane HL).

[0039] <<Right deviation prevention operation start condition>> (Condition CR1) It is estimated that the right front end of the host vehicle HV reaches the right outer reference line ROT after a certain time T. The driving support ECU 10 determines whether condition CR1 is satisfied in the same manner as when determining whether condition CL1 is satisfied. That is, the driving support ECU 10 predicts the position of the host vehicle HV in the lane width direction after a certain time T based on the distance DR from the center line RC of the right boundary line RLM in the lane width direction of the host vehicle HV at the current time, the rightward speed (right lateral speed) of the host vehicle HV in the lane width direction, and the rightward acceleration (right lateral acceleration) of the host vehicle HV in the lane width direction, and determines whether condition CR1 is satisfied based on that position. (Condition CR2) At the current time, the right front end of the host vehicle HV has reached the right inner reference line RIN.

[0040] <Rear approaching vehicle corresponding control> By the way, as shown in FIG. 2(B), when the host vehicle HV blinks the turn signal, it is determined that the driver of the host vehicle HV intends to change lanes of the host vehicle HV, so the deviation suppression support operation including the lane departure prevention operation (left deviation prevention operation and / or right deviation prevention operation) is temporarily canceled (stopped, restricted). At this time, when "a rear approaching vehicle RV approaching the host vehicle HV from behind within the own lane HL" is about to change lanes from the own lane HL to an adjacent lane (RL or LL) to overtake the host vehicle HV, the possibility that the host vehicle HV and the rear vehicle RV approach excessively in the adjacent lane becomes high.

[0041] Therefore, when there is a vehicle RV approaching from behind, the present device DS prohibits the deviation suppression support operation from being temporarily canceled even if the host vehicle HV blinks the turn signal. That is, in this case, even if the host vehicle HV blinks the turn signal, either the left deviation prevention operation or the right deviation prevention operation is executed as necessary.

[0042] (Specific operation) The CPU of the driving support ECU 10 (hereinafter simply referred to as "CPU") executes the routine shown by the flowchart in FIGS. 3 and 4 every time a predetermined time (operation cycle) dt elapses. In the following, "step" is denoted as "S". The values of each flag described below are set to "0" in an initialization routine (not shown) executed by the CPU when the host vehicle HV is started.

[0043] <Lane departure prevention (suppression) control> At a predetermined timing, the CPU starts processing from S300 in FIG. 3 and proceeds to S305, and determines whether the value of the right deviation prevention operation execution flag XRex is "0". The right deviation prevention operation execution flag XRex indicates that the right deviation prevention operation is being executed when its value is "1", and indicates that the right deviation prevention operation is not being executed when its value is "0".

[0044] When the value of the right deviation prevention operation execution flag XRex is "0", the CPU proceeds from S305 to S310 and determines whether the right deviation prevention operation start condition (either one of the above-described conditions CR1 and CR2) is satisfied. When the right deviation prevention operation start condition is satisfied, the CPU proceeds from S310 to S315, sets the value of the right deviation prevention operation execution flag XRex to "1", and proceeds to S320. When the right deviation prevention operation start condition is not satisfied, the CPU proceeds directly from S310 to S320.

[0045] The CPU determines whether the value of the right OR (override) permission flag XRor is "1" at S320. When the value of the right OR permission flag XRor is "1", the right deviation prevention operation is canceled (stopped, prohibited), allowing the host vehicle HV to deviate to the right from the right boundary line RLM. That is, when the right OR permission flag XRor is set to "1", the driving operation (right override) for the driver of the host vehicle HV to change lanes to the adjacent right lane is permitted. When the value of the right OR permission flag XRor is "0", the right override is prohibited and the right deviation prevention operation is permitted.

[0046] When the value of the right OR permission flag XRor is "1", the CPU proceeds from S320 to S325, sets the value of the right deviation prevention operation execution flag XRex to "0", and proceeds to S330. When the value of the right OR permission flag XRor is "0", the CPU proceeds directly from S320 to S330. Therefore, the right override is permitted by the processing of S320 and S325.

[0047] The CPU determines whether the value of the right deviation prevention operation execution flag XRex is "1" at S335. When the value of the right deviation prevention operation execution flag XRex is "1", the CPU proceeds from S330 to S335 and automatically steers the host vehicle HV to the left so that the host vehicle HV does not deviate from the right boundary line RLM to the outside (right side) of its own lane HL. That is, the CPU executes the right deviation prevention operation as a lane departure prevention operation.

[0048] At the same time, the CPU executes an alarm generation operation to generate an alarm for the driver of the host vehicle at S330. That is, the CPU causes the display device 51 to display the alarm mark and causes the alarm sound to be generated from the speaker 52. In this case, the alarm mark displayed at S335 may simply be "a mark indicating that the host vehicle may deviate from its own lane", or may be "a mark indicating that the host vehicle may deviate to the right from its own lane". Similarly, the alarm sound generated at S335 may simply be "a sound (warning sound) indicating that the host vehicle may deviate from its own lane", or may be "a message voice indicating that the host vehicle may deviate to the right from its own lane". Thereafter, the CPU proceeds to S355.

[0049] On the other hand, when the value of the right deviation prevention operation execution flag XRex is not "1", the CPU proceeds directly from S330 to S355.

[0050] On the other hand, when the CPU proceeds to S305 and the value of the right deviation prevention operation execution flag XRex is "1", the CPU proceeds from S305 to S340 and determines whether the end condition of the right deviation prevention operation is satisfied. The end condition of the right deviation prevention operation is satisfied, for example, when the right deviation prevention operation is continuously executed for a certain period of time or more, and when the entire host vehicle HV is located on the center side of the own lane HL with respect to the right inner reference line RIN.

[0051] When the end condition of the right deviation prevention operation is satisfied, the CPU proceeds from S340 to S345, sets the value of the right deviation prevention operation execution flag XRex to "0", and sets the value of the right OR permission flag XRоr to "0" at S350. Thereafter, the CPU proceeds to S320. When the end condition of the right deviation prevention operation is not satisfied, the CPU proceeds directly from S340 to S320.

[0052] When the CPU proceeds to S355, it determines whether the value of the left deviation prevention operation execution flag XLex is "0". The left deviation prevention operation execution flag XLex indicates that the left deviation prevention operation is in progress when its value is "1", and indicates that the left deviation prevention operation is not in progress when its value is "0".

[0053] If the value of the left deviation prevention operation execution flag XLex is "0", the CPU proceeds from S355 to S360 and determines whether the left deviation prevention operation start condition (either one of the above-mentioned conditions CL1 and CL2) is satisfied. If the left deviation prevention operation start condition is satisfied, the CPU proceeds from S360 to S365, sets the value of the left deviation prevention operation execution flag XLex to "1", and proceeds to S370. If the left deviation prevention operation start condition is not satisfied, the CPU proceeds directly from S360 to S370.

[0054] At S370, the CPU determines whether the value of the left OR (override) permission flag XLоr is "1". The left OR permission flag XLоr allows the host vehicle HV to deviate to the left from the left boundary line RLM by canceling (stopping, prohibiting) the left deviation prevention operation when its value is "1". That is, when the left OR permission flag XLоr is set to "1", the driving operation (left override) for the driver of the host vehicle HV to change lanes to the left adjacent lane is permitted. The left OR permission flag XLоr prohibits the left override and allows the left deviation prevention operation when its value is "0".

[0055] If the value of the left OR permission flag XLоr is "1", the CPU proceeds from S370 to S375, sets the value of the left deviation prevention operation execution flag XLex to "0", and proceeds to S380. If the value of the left OR permission flag XLоr is "0", the CPU proceeds directly from S370 to S380. Therefore, the left override is permitted by the processing at S370 and S375.

[0056] The CPU determines whether the value of the left deviation prevention operation execution flag XLex is "1" at S380. When the value of the left deviation prevention operation execution flag XLex is "1", the CPU proceeds from S380 to S385 and automatically steers the host vehicle HV to the right so that the host vehicle HV does not deviate from the left boundary line LLM to the outside (left side) of the host lane HL. That is, the CPU executes the left deviation prevention operation as a lane departure prevention operation.

[0057] At the same time, the CPU executes an alarm generation operation to generate an alarm for the driver of the host vehicle at S385. That is, the CPU causes the display device 51 to display the alarm mark and causes the speaker 52 to generate the alarm sound. In this case, the alarm mark displayed at S385 may simply be "a mark indicating that the host vehicle may deviate from the host lane" or "a mark indicating that the host vehicle may deviate from the host lane to the left side". Similarly, the alarm sound generated at S385 may simply be "a sound (warning sound) indicating that the host vehicle may deviate from the host lane" or "a message voice indicating that the host vehicle may deviate from the host lane to the left side". Thereafter, the CPU proceeds to S395 and temporarily ends this routine.

[0058] On the other hand, when the value of the left deviation prevention operation execution flag XLex is not "1", the CPU proceeds directly from S380 to S395.

[0059] On the other hand, when the CPU proceeds to S355, if the value of the left deviation prevention operation execution flag XLex is "1", the CPU proceeds from S355 to S390 and determines whether the end condition of the left deviation prevention operation is satisfied. The end condition of the left deviation prevention operation is satisfied, for example, when the left deviation prevention operation is continuously executed for a certain period of time or when the entire host vehicle HV is located on the center side of the host lane HL with respect to the left inner reference line LIN.

[0060] When the termination condition of the left deviation prevention operation is satisfied, the CPU proceeds from S390 to S392, sets the value of the left deviation prevention operation execution flag XLex to "0", and sets the value of the left OR permission flag XLоr to "0" at S394. Then, the CPU proceeds to S370. When the termination condition of the left deviation prevention operation is not satisfied, the CPU proceeds directly from S390 to S370.

[0061] <Override Permission / Prohibition Judgment> At a predetermined timing, the CPU starts processing from S400 in FIG. 4 and proceeds to S405, and determines whether the right turn signal 32R of the host vehicle HV is in an on state (flashing state) based on the signal from the turn signal switch 30.

[0062] When the right turn signal 32R is not in the flashing state, the CPU proceeds directly from S405 to S410 and sets the value of the right OR permission flag XRоr to "0". Then, the CPU proceeds to S435.

[0063] When the right turn signal 32R is in the flashing state, the CPU proceeds from S405 to S415 and determines whether there is a "right adjacent lane where the host vehicle HV can change lanes" on the right side of the host lane based on the front camera image (or information obtained from the navigation ECU 70). For example, in the examples shown in FIGS. 5(A), 5(B), and 5(C), there is a right adjacent lane where the host vehicle HV can change lanes. When there is no right adjacent lane, the CPU proceeds from S415 to S410.

[0064] When there is a right adjacent lane, the CPU proceeds from S415 to S425 and determines whether there is a vehicle (i.e., a rear approaching vehicle) RV that is located within the host lane HL and approaches the host vehicle HV from behind the host vehicle HV based on the rear image data (or information obtained by vehicle-to-vehicle communication with the rear approaching vehicle). When there is no rear approaching vehicle RV, the CPU proceeds from S425 to S420 and sets the value of the right OR permission flag XRоr to "1". Then, the CPU proceeds to S435.

[0065] As shown in (D) of FIG. 5, when there is a rear approaching vehicle RV, the CPU proceeds from S425 to S430 and determines whether the intention to change lanes to the right adjacent lane of the rear approaching vehicle RV can be confirmed. For example, when the CPU can confirm any of the following cases, it determines that the intention to change lanes to the right adjacent lane of the rear approaching vehicle RV can be confirmed.

[0066] (Case R1) As shown in FIG. 6(A), when the CPU can confirm that the right turn signal RT of the rear adjacent vehicle RV is in a blinking state based on the rear image data. (Case R2) As shown in FIG. 6(B), when the CPU can confirm that the "rightward moving speed VL and / or rightward moving acceleration dVL / dt" in the lane width direction of the rear approaching vehicle RV is greater than their respective threshold values based on the rear image data and / or rear radar information. (Case R3) As shown in FIG. 6(C), through vehicle-to-vehicle communication (wireless communication between the host vehicle HV and the rear adjacent vehicle RV), when the CPU obtains information that the right turn signal RT of the rear adjacent vehicle RV is in a blinking state and / or the driver of the rear adjacent vehicle RV has steered the steering wheel to the right by a predetermined angle or more.

[0067] When the CPU does not determine that the intention to change lanes to the right adjacent lane of the rear approaching vehicle RV can be confirmed, it proceeds from S430 to S420 and sets the value of the right OR permission flag XRоr to "1". Then, the CPU proceeds to S435.

[0068] When the CPU determines that the intention to change lanes to the right adjacent lane of the rear approaching vehicle RV can be confirmed, it proceeds from S430 to S410 and sets the value of the right OR permission flag XRоr to "0". Then, the CPU proceeds to S435.

[0069] At S435, the CPU determines whether the left turn signal 32L of the host vehicle HV is in an on state (blinking state) based on the signal from the turn signal switch 30.

[0070] When the left turn signal 32L is not in a blinking state, the CPU directly proceeds from S435 to S440 and sets the value of the left OR permission flag XLоr to "0". Then, the CPU proceeds to S495 and temporarily ends this routine.

[0071] When the left turn signal 32L is in a blinking state, the CPU proceeds from S435 to S445 and determines whether there is a "left adjacent lane where the host vehicle HV can change lanes" on the left side of the host lane based on the front camera image (or information obtained from the navigation ECU 70). If there is no left adjacent lane, the CPU proceeds from S445 to S440.

[0072] If there is a left adjacent lane, the CPU proceeds from S445 to S455 and determines whether there is a rear approaching vehicle RV based on the rear image data (or information obtained through vehicle-to-vehicle communication with the rear approaching vehicle). If there is no rear approaching vehicle RV, the CPU proceeds from S455 to S450 and sets the value of the left OR permission flag XLоr to "1". Then, the CPU proceeds to S495.

[0073] As shown in (D) of FIG. 5, when there is a rear approaching vehicle RV, the CPU proceeds from S455 to S460 and determines whether the intention of the rear approaching vehicle RV to change lanes to the left adjacent lane can be confirmed. For example, the CPU determines that the intention of the rear approaching vehicle RV to change lanes to the left adjacent lane can be confirmed when any of the following cases can be confirmed.

[0074] (Case L1) When the CPU can confirm based on the rear image data that the left turn signal LT of the rear adjacent vehicle RV is in a blinking state. (Case L2) When the CPU can confirm based on the rear image data and / or the rear radar information that the "leftward movement speed VR and / or leftward movement acceleration dVR / dt" in the lane width direction of the rear approaching vehicle RV are each greater than their respective threshold values. (Case L3) When the CPU acquires information that the left turn signal LT of the adjacent vehicle RV behind has started flashing and / or the driver of the adjacent vehicle RV behind has steered the steering wheel to the left by a predetermined angle or more through vehicle-to-vehicle communication.

[0075] If the CPU does not determine that the intention of the adjacent vehicle RV behind to change lanes to the left adjacent lane can be confirmed, it proceeds from S460 to S450 and sets the value of the left OR permission flag XLоr to "1". Then, the CPU proceeds to S495.

[0076] If the CPU determines that the intention of the adjacent vehicle RV behind to change lanes to the left adjacent lane can be confirmed, it proceeds from S460 to S440 and sets the value of the left OR permission flag XLоr to "0". Then, the CPU proceeds to S495.

[0077] As described above, when a rear approaching vehicle that is located within the own lane and approaches the own vehicle from behind is detected, the device DS does not cancel the execution of the lane departure prevention operation even when the turn signal of the own vehicle starts flashing. That is, the device DS permits the execution of the lane departure prevention operation in such a case. Therefore, since the own vehicle does not deviate from the own lane, it is possible to prevent the occurrence of a situation in which the own vehicle obstructs the progress of a rear vehicle that attempts to overtake the own vehicle by changing lanes.

[0078] (Modification example) Next, a modification example of the device DS will be described. The device DS according to this modification example differs from the device DS according to the above-described embodiment only in that the CPU of the driving support ECU10 executes each of the routines shown by the flowcharts in FIGS. 7 to 9 instead of FIGS. 3 and 4 every time a predetermined time dt elapses. In particular, the device DS according to this modification example differs from the device DS according to the above-described embodiment in that it uses a "departure prevention operation execution flag Xex and OR permission flag Xоr" common to the left departure prevention operation and the right departure prevention operation, and does not confirm the intention of the rear approaching vehicle to change lanes.

[0079] <Lane departure prevention (suppression) control> When the specified timing arrives, the CPU starts processing from S700 in FIG. 7 and proceeds to S705, and determines whether the value of the deviation prevention operation execution flag Xex is "0". This flag Xex indicates that either the right deviation prevention operation or the left deviation prevention operation is being executed when its value is "1", and indicates that neither the right deviation prevention operation nor the left deviation prevention operation is being executed when its value is "0".

[0080] If the value of the deviation prevention operation execution flag Xex is "0", the CPU proceeds from S705 to S710 and determines whether either one of the above-mentioned "right deviation prevention operation start condition and left deviation prevention operation start condition" is satisfied.

[0081] If either one of the "right deviation prevention operation start condition and left deviation prevention operation start condition" is satisfied, the CPU proceeds from S710 to S715, sets the value of the deviation prevention operation execution flag Xex to "1", and then the CPU proceeds to S720.

[0082] On the other hand, if the CPU determines "No" at S705, it proceeds directly from S705 to S720. Further, if the CPU determines "No" at S710, it proceeds directly from S710 to S720.

[0083] The CPU determines whether the value of the OR (override) permission flag Xor is "1" at S720. The OR permission flag Xor allows the host vehicle HV to deviate from its own lane by canceling (stopping, prohibiting) both the right deviation prevention operation and the left deviation prevention operation when its value is "1". That is, when the OR permission flag Xor is set to "1", the driving operation (override) for lane change to the left adjacent lane and the right adjacent lane by the driver of the host vehicle HV is permitted. The OR permission flag Xor prohibits override and allows the execution of the deviation prevention operation (right deviation prevention operation and left deviation prevention operation) when its value is "0".

[0084] When the value of the OR permission flag Xor is "1", the CPU proceeds from S720 to S725, sets the value of the deviation prevention operation execution flag Xex to "0", and proceeds to S730. When the value of the OR permission flag Xor is "0", the CPU proceeds directly from S720 to S730. Therefore, the deviation prevention operation is canceled (prohibited) and overriding is allowed by the processing of S720 and S725.

[0085] The CPU determines at S730 whether the value of the deviation prevention operation execution flag Xex is "1". When the value of the deviation prevention operation execution flag Xex is "1", the CPU proceeds from S730 to S735 and executes an alarm generation operation to generate an alarm for the driver of the host vehicle. That is, the CPU causes the display device 51 to display the alarm mark and causes the speaker 52 to generate the alarm sound. The alarm mark displayed at S735 may simply be "a mark indicating that the host vehicle may deviate from its own lane" or "a mark indicating the side from which the host vehicle is deviating". Similarly, the alarm sound generated at S735 may simply be "a sound (warning sound) indicating that the host vehicle may deviate from its own lane" or "a message voice indicating that the host vehicle may deviate from its own lane and which side (left or right) the host vehicle is deviating towards". Thereafter, the CPU proceeds to S740.

[0086] The CPU determines at S740 whether the host vehicle is deviating to the right from its own lane. When the host vehicle is deviating to the right, the CPU proceeds from S740 to S745 and automatically steers the host vehicle HV to the left so that the host vehicle HV does not deviate outside (to the right) of the own lane HL from the right boundary line RLM.

[0087] On the other hand, when the host vehicle is deviating to the left, the CPU proceeds from S740 to S750 and automatically steers the host vehicle HV to the right so that the host vehicle HV does not deviate outside (to the left) of the own lane HL from the left boundary line LLM.

[0088] <End of lane departure prevention (suppression) control> When the specified timing arrives, the CPU starts processing from S800 in FIG. 8 and proceeds to S810, and determines whether or not the end condition of the right deviation prevention operation described above is satisfied during the execution of the right deviation prevention operation. If the end condition of the right deviation prevention operation is satisfied during the execution of the right deviation prevention operation, the CPU proceeds from S810 to S830.

[0089] On the other hand, if the end condition of the right deviation prevention operation is not satisfied during the execution of the right deviation prevention operation, the CPU proceeds from S810 to S820, and determines whether or not the end condition of the left deviation prevention operation described above is satisfied during the execution of the left deviation prevention operation. If the end condition of the left deviation prevention operation is not satisfied during the execution of the left deviation prevention operation, the CPU proceeds directly from S820 to S895 and temporarily ends this routine. If the end condition of the left deviation prevention operation is satisfied during the execution of the left deviation prevention operation, the CPU proceeds from S820 to S830.

[0090] At S830, the CPU sets the value of the deviation prevention operation execution flag Xex to "0". Next, at S840, the CPU sets the value of the OR permission flag Xor to "0". Then, the CPU proceeds to S895 and temporarily ends this routine.

[0091] (Override Permission / Prohibition Judgment) When the specified timing arrives, the CPU starts processing from S900 in FIG. 9 and proceeds to S910, and determines whether or not either one of the "right turn signal 32R and left turn signal 32L" of the host vehicle is in a blinking state.

[0092] If either one of the "right turn signal 32R and left turn signal 32L" of the host vehicle is in a blinking state, the CPU proceeds from S910 to S920 and sets the value of the OR permission flag Xor to "1". Then, the CPU proceeds to S940.

[0093] On the other hand, if neither of the "right turn signal 32R and left turn signal 32L" of the host vehicle is in a blinking state, the CPU proceeds from S910 to S930 and sets the value of the OR permission flag Xor to "0". Then, the CPU proceeds to S940.

[0094] The CPU determines at S940 whether the value of the OR permission flag Xor is "1". If the value of the OR permission flag Xor is "1", the CPU proceeds from S940 to S950 and determines based on the rear image data whether there is a vehicle approaching from behind within its own lane.

[0095] If there is a vehicle approaching from behind, the CPU proceeds from S950 to S960 and sets the value of the OR permission flag Xor to "0". As a result, the execution of the deviation prevention operation is allowed without being canceled. Then, the CPU proceeds to S995 and temporarily ends this routine.

[0096] Note that if the value of the OR permission flag Xor is not "1", the CPU proceeds directly from S940 to S995 and temporarily ends this routine. Further, if there is no vehicle approaching from behind within its own lane, the CPU proceeds directly from S950 to S995 and temporarily ends this routine.

[0097] The above is the specific operation of the device DS according to the modified example. Thus, when either one of the "right turn signal 32R and left turn signal 32L" of the host vehicle is in a blinking state, the device DS according to the modified example prohibits (cancels) both the right deviation prevention operation and the left deviation prevention operation. In that case, when a vehicle approaching from behind is detected, the device DS according to the modified example permits both the right deviation prevention operation and the left deviation prevention operation.

[0098] The present invention is not limited to the above-described embodiments and modified examples, and various modified examples can be adopted within the scope of the present invention. For example, even if the CPU does not determine at S430 in FIG. 4 that the intention to change lanes to the right adjacent lane of the vehicle RV approaching from behind has been confirmed, the CPU may proceed from S430 to S410 and set the value of the right OR permission flag XRor to "0". That is, when the right turn signal 32R of the host vehicle HV is in a blinking state and there is a vehicle approaching from behind, the CPU may allow the execution of the right deviation prevention operation without canceling it and prohibit the right override regardless of whether the intention to change lanes of the vehicle approaching from behind has been confirmed.

[0099] Similarly, even when the CPU determines at S460 that it cannot confirm the intention of the vehicle in the rear approaching vehicle RV to change lanes to the left adjacent lane, the CPU may proceed from S460 to S440 and set the value of the left OR permission flag XLOR to "0". That is, when the left turn signal 32L of the host vehicle HV is blinking and there is a vehicle approaching from the rear, the CPU may allow, without canceling the execution of the left deviation prevention operation, the left override to be prohibited regardless of whether the intention of the vehicle approaching from the rear to change lanes can be confirmed.

[0100] Furthermore, as in the modified example, when one of the left turn signal 32L and the right turn signal 32R of the host vehicle HV is blinking, the CPU may prohibit (cancel) both the left deviation prevention operation and the right deviation prevention operation and allow both the left override and the right override. In this case, when there is a vehicle approaching from the rear, regardless of whether the intention of the vehicle approaching from the rear to change lanes can be confirmed, the CPU may allow, without canceling the lane departure prevention operation to the overtaking lane side (the "higher speed lane side" adjacent to the host lane HL) with respect to the host lane HL, and only prohibit the override to the overtaking lane side. Note that, for example, in a region having regulations that vehicles travel on the left side of the road like in Japan, the overtaking lane side of the host lane HL means the right adjacent lane side (right) of the host lane HL. In a region having regulations that vehicles travel on the right side of the road like in the United States, the overtaking lane side of the host lane HL means the left adjacent lane side (left) of the host lane HL.

[0101] In addition, as in the modified example, when the CPU is configured to prohibit (cancel) both the left deviation prevention operation and the right deviation prevention operation and allow both the left override and the right override when one of the left turn signal 32L and the right turn signal 32R of the host vehicle HV is blinking, (1) When a vehicle approaching from the rear is detected and the intention of the vehicle approaching from the rear to change lanes to the right adjacent lane can be confirmed, at least the right override may be prohibited (the execution of the right deviation prevention operation may be allowed). (2) When a vehicle approaching from behind is detected and an intention to change lanes to the left adjacent lane of the vehicle approaching from behind can be confirmed, it may be possible to prohibit at least the left override (allow the execution of the left departure prevention operation).

[0102] Further, for example, the present invention is applicable to a host vehicle in a state where the driving mode has transitioned from automatic driving to driving by a driver in an autonomous vehicle.

Explanation of Signs

[0103] 10... Driving support ECU (control unit), 20... Front camera, 21... Rear camera, 22... Right rear radar, 23... Left rear radar, 32L... Left turn signal, 32R... Right turn signal, 40... Steering motor.

Claims

1. When there is a possibility that the host vehicle may deviate from the host lane, at least one of an alarm generation operation for generating an alarm to the driver of the host vehicle and a lane departure prevention operation for automatically applying a force in a direction to avoid deviation from the host lane to the host vehicle is executed as a deviation suppression support operation, and when the turn signal of the host vehicle is in a blinking state, a control unit configured to cancel the execution of the deviation suppression support operation is provided in a lane departure prevention device, wherein the control unit is configured to allow execution of the deviation suppression support operation without canceling it even when the turn signal of the host vehicle is in a blinking state when there is a rear approaching vehicle that is located within the host lane and approaches the host vehicle from behind the host vehicle, a lane departure prevention device.

2. In the lane departure prevention device according to Claim 1, the control unit is configured to execute the lane departure prevention operation as the deviation suppression support operation, and determines whether the rear approaching vehicle is about to change lanes to a right adjacent lane adjacent to the right side of the host lane, and when it is determined that the rear approaching vehicle is about to change lanes to the right adjacent lane, even when the turn signal of the host vehicle is in a blinking state, at least the execution of the lane departure prevention operation for avoiding deviation of the host vehicle to the right adjacent lane side is configured to be allowed without canceling it, a lane departure prevention device.

3. In the lane departure prevention device according to Claim 1, the control unit is configured to execute the lane departure prevention operation as the deviation suppression support operation, and determines whether the rear approaching vehicle is about to change lanes to a left adjacent lane adjacent to the left side of the host lane, and when it is determined that the rear approaching vehicle is about to change lanes to the left adjacent lane, even when the turn signal of the host vehicle is in a blinking state, at least the execution of the lane departure prevention operation for avoiding deviation of the host vehicle to the left adjacent lane side is configured to be allowed without canceling it, a lane departure prevention device.

4. In the lane departure prevention device according to Claim 1, the control unit is configured to execute the lane departure prevention operation as the deviation suppression support operation, and When there is a vehicle approaching from behind, even when the turn signal of the host vehicle is blinking, it is configured to allow execution of the lane departure prevention operation against deviation to the overtaking lane side with respect to at least the host lane without canceling it. Lane departure prevention device.

5. In the lane departure prevention device according to claim 1, The control unit is configured to execute the lane departure prevention operation as the deviation suppression support operation, and when the right turn signal among the turn signals of the host vehicle is blinking, it is configured to cancel the execution of the right deviation prevention operation among the lane departure prevention operations for suppressing the host vehicle from deviating to the right from the host lane. It determines whether the vehicle approaching from behind is about to change lanes to a right adjacent lane adjacent to the right side of the host lane. When it is determined that the vehicle approaching from behind is about to change lanes to the right adjacent lane, even when the right turn signal of the host vehicle is blinking, it is configured to allow execution of at least the right deviation prevention operation without canceling it. when the left turn signal among the turn signals of the host vehicle is blinking, it is configured to cancel the execution of the left deviation prevention operation among the lane departure prevention operations for suppressing the host vehicle from deviating to the left from the host lane. It determines whether the vehicle approaching from behind is about to change lanes to a left adjacent lane adjacent to the left side of the host lane. When it is determined that the vehicle approaching from behind is about to change lanes to the left adjacent lane, even when the left turn signal of the host vehicle is blinking, it is configured to allow execution of at least the left deviation prevention operation without canceling it. Lane departure prevention device.

6. In the lane departure prevention device according to claim 5, The control unit is configured to allow cancellation of the execution of the right deviation prevention operation only when there is a right adjacent lane, which is a lane adjacent to the host lane where the host vehicle can change lanes to the right, when the right turn signal of the host vehicle is blinking. When the left turn signal of the host vehicle is in a blinking state, cancellation of the execution of the left deviation prevention operation is permitted only when there is a left adjacent lane, which is a lane adjacent to the host lane in which the host vehicle can change lanes to the left. Lane departure prevention device. **Claim 7** When there is a possibility that the host vehicle may deviate from the host lane, at least one of an alarm generation operation for generating an alarm to the driver of the host vehicle and a lane departure prevention operation for automatically applying a force in a direction to avoid deviation of the host vehicle from the host lane is executed as a deviation suppression support operation; When the turn signal of the host vehicle is in a blinking state, canceling the execution of the deviation suppression support operation; When there is a rear approaching vehicle that is located within the host lane and approaches the host vehicle from behind the host vehicle, even when the turn signal of the host vehicle is in a blinking state, permitting the execution of the deviation suppression support operation without canceling it; A lane departure prevention method including the above. **Claim 8** A program to be executed by a computer mounted on a host vehicle, The program causes the computer to When there is a possibility that the host vehicle may deviate from the host lane, at least one of an alarm generation operation for generating an alarm to the driver of the host vehicle and a lane departure prevention operation for automatically applying a force in a direction to avoid deviation of the host vehicle from the host lane is executed as a deviation suppression support operation; When the turn signal of the host vehicle is in a blinking state, canceling the execution of the deviation suppression support operation; When there is a rear approaching vehicle that is located within the host lane and approaches the host vehicle from behind the host vehicle, even when the turn signal of the host vehicle is in a blinking state, permitting the execution of the deviation suppression support operation without canceling it; A program for causing the above to be executed.

Images