Lane departure prevention device, lane departure prevention method, and lane departure prevention program

Abstract

To provide a lane departure prevention device that can provide driving assistance that meets the driver's expectations around the zebra zone (by performing lane departure prevention control at the appropriate position). [Solution] The processor determines that a predetermined condition is met if there is a second lane L2_R connected to one end of the first lane L1 to the side of the forward area FR of the vehicle in the first lane L1, the vehicle cannot enter the second lane L2_R until it reaches the forward area FR, it is possible to enter the second lane L2_R in the forward area FR, a zebra zone ZR extends to the forward area FR, and the distance DFR between the vehicle and the forward area FR is less than or equal to the threshold DFRth, or the time ΔtR that is predicted to take for the vehicle to reach the forward area is less than or equal to the threshold Δtth.

Description

Technical Field

[0001] The present invention relates to a lane departure suppression device, a lane departure suppression method, and a lane departure suppression program that control a predetermined device of a host vehicle so as to suppress the host vehicle from deviating from the lane (travel lane) in which it is traveling.

Background Art

[0002] A lane departure suppression device that controls a predetermined device of a host vehicle so as to suppress the host vehicle from deviating from the lane in which it is traveling has been proposed (see, for example, Patent Document 1 below). This lane departure suppression device (hereinafter referred to as the "conventional device") has a导流带 (zebra zone) extending in the longitudinal direction along the lateral end of the lane in which the host vehicle is traveling, and when there are other vehicles or pedestrians in the zebra zone, lane departure suppression control (driving support) is executed to control a predetermined device of the host vehicle so as to suppress entry from the area outside the zebra zone in the lane into the zebra zone. Further, when there are no other vehicles or the like in the zebra zone and there is a lane mark (a white line, pole, guardrail, etc. that demarcates the lane in which the host vehicle is traveling from other lanes) in the zebra zone, the conventional device executes lane departure suppression control so as to suppress the host vehicle from approaching the lane mark excessively.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] Conventional systems do not perform lane departure prevention control when the vehicle approaches the zebra zone from outside, provided there are no other vehicles within the zebra zone. However, even when there are no other vehicles within the zebra zone, drivers who prefer to avoid entering the zebra zone are likely to expect that lane departure prevention control will be performed when their vehicle approaches the zebra zone to a certain extent. However, for example, in a scenario where a zebra zone is provided before a right-turn lane or a left-turn lane, and the driver intentionally enters the zebra zone to enter the right-turn or left-turn lane, the driver is likely to expect that lane departure prevention control will not be performed when their vehicle approaches the zebra zone.

[0005] One of the objectives of the present invention is to provide a lane departure prevention device that can provide driving assistance that meets the driver's expectations around a zebra zone (i.e., can perform lane departure prevention control at an appropriate position).

[0006] To achieve the above objective, the lane departure prevention device (1) of the present invention is: An on-board sensor (20) acquires information about a target located in front of the vehicle (V0), A processor configured to perform lane departure suppression processing to control predetermined devices (30, 40) of the vehicle so as to suppress the vehicle from deviating outside the predetermined reference lines (BR, BL) extending in the direction of extension of the first lane (L1) in which the vehicle is traveling, when the lateral distance (DR, DL) between the vehicle and the vehicle is less than or equal to a threshold (DRth, DLth), wherein the processor is configured to select the lateral end (L1R, L1L) of the first lane as the reference line when a zebra zone (ZR, ZL) extending longitudinally along one end of the first lane in the lateral direction exists within the first lane and predetermined conditions (XR, XL) are met, and when the zebra zone exists within the first lane and the predetermined conditions are not met, select the lateral end (ZRL, ZLR) of the zebra zone that is opposite to the lateral end of the first lane as the reference line. It is equipped with. The aforementioned processor, To the side of the area in front of the vehicle in the first lane, there is a second lane connected to one end of the first lane (XR1, XL1), The vehicle is unable to enter the second lane until it reaches the forward area, and is able to enter the second lane within the forward area (XR2, XL2), The zebra zone extends to the forward region (XR3, XL3), and, The system is configured to determine that the predetermined conditions are met when the distance between the vehicle and the forward area is below a threshold, or when the time it is estimated that the vehicle will need to reach the forward area is below a threshold (XR4, XL4).

[0007] Furthermore, in order to achieve the above objectives, the lane departure suppression method of the present invention is An information acquisition step to acquire information about a target located in front of the vehicle, A control step for executing a lane departure prevention process to control a predetermined device of a vehicle so as to prevent the vehicle from deviating outside the predetermined reference line when the lateral distance between the vehicle and a predetermined reference line extending in the direction of extension of the first lane in which the vehicle is traveling is below a threshold, wherein the control step is configured to select the lateral end of the first lane as the reference line when a zebra zone extending longitudinally along one lateral end of the first lane exists within the first lane and predetermined conditions are met, and to select the lateral end of the zebra zone opposite to the lateral end of the first lane as the reference line when the zebra zone exists within the first lane and the predetermined conditions are not met, Includes. The control step described above is: To the side of the area in front of the vehicle in the first lane, there exists a second lane connected to one end of the first lane, The vehicle is unable to enter the second lane until it reaches the area ahead, and is able to enter the second lane within the area ahead. The zebra zone extends to the forward region, and The system is configured to include a step of determining that the predetermined conditions are met if the distance between the vehicle and the forward area is less than or equal to a threshold, or if the time it is estimated that the vehicle will need to reach the forward area is less than or equal to a threshold.

[0008] Furthermore, in order to achieve the above objectives, the lane departure prevention program of the present invention is The computer installed in the vehicle, An information acquisition step to acquire information about a target located in front of the vehicle, A control step for executing a lane departure prevention process to control a predetermined device of a vehicle so as to prevent the vehicle from deviating outside the predetermined reference line when the lateral distance between the vehicle and a predetermined reference line extending in the direction of extension of the first lane in which the vehicle is traveling is below a threshold, wherein the control step is configured to select the lateral end of the first lane as the reference line when a zebra zone extending longitudinally along one lateral end of the first lane exists within the first lane and predetermined conditions are met, and to select the lateral end of the zebra zone opposite to the lateral end of the first lane as the reference line when the zebra zone exists within the first lane and the predetermined conditions are not met, Make it run. The control step described above is: To the side of the area in front of the vehicle in the first lane, there exists a second lane connected to one end of the first lane, The vehicle is unable to enter the second lane until it reaches the area ahead, and is able to enter the second lane within the area ahead. The zebra zone extends to the forward region, and The process includes a step of determining that the predetermined conditions are met if the distance between the vehicle and the forward area is less than or equal to a threshold, or if the time it is estimated that the vehicle will need to reach the forward area is less than or equal to a threshold.

[0009] In the lane departure prevention device (lane departure prevention method, lane departure prevention program) according to the present invention, the processor selects either one of the ends of the first lane or the end of the zebra zone as the reference line depending on whether predetermined conditions are met. Here, if the above four conditions (conditions XR1 to XR4 (conditions XL1 to XL4)) are met, there is a high probability that the driver of the vehicle will intentionally enter the zebra zone. Therefore, when these conditions are met (when predetermined conditions are met), the processor selects the end of the first lane as the reference line. On the other hand, if the predetermined conditions are not met, the processor selects the end of the zebra zone as the reference line. That is, when there is a low probability that the driver will intentionally enter the zebra zone, the processor executes lane departure prevention control when the vehicle approaches the zebra zone to a certain extent (when the lateral distance between the zebra zone and the vehicle falls below a threshold). On the other hand, if the processor is likely to intentionally drive its vehicle into a zebra zone, it will not execute lane departure prevention control even when the vehicle is relatively close to the zebra zone. Instead, it will execute lane departure prevention control when the vehicle has entered the zebra zone and is relatively close to the edge of the first lane. In this way, the lane departure prevention device according to the present invention can provide driving assistance that meets the driver's expectations around the zebra zone (it can execute lane departure prevention control at an appropriate position).

[0010] In a lane departure prevention device according to one aspect of the present invention, The aforementioned second lane is either a right-turn lane or a left-turn lane. The front end of the zebra zone is connected to the right-turn lane or the left-turn lane.

[0011] According to the lane departure prevention device of this embodiment, driving assistance that meets the driver's expectations is provided around the zebra zone provided before the right-turn lane or left-turn lane.

[0012] In another aspect of the present invention, a lane loss prevention device, The first lane is an acceleration lane, and the second lane is a main lane.

[0013] According to the lane departure suppression device according to this aspect, driving support along the driver's expectation is provided in the vicinity of the zebra zone provided in front of the merging area of the acceleration lane and the main lane.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 is a block diagram of a lane departure suppression device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing a scene where the host vehicle enters the right-turn lane. [Figure 3] FIG. 3 is a plan view showing a scene where the host vehicle enters from the acceleration lane to the main lane. [Figure 4] FIG. 4 is a plan view showing a scene where the host vehicle advances without entering the zebra zone. [Figure 5] FIG. 5 is a flowchart of a program executed by the CPU to realize the lane departure suppression function.

Mode for Carrying Out the Invention

[0015] (Schematic) As shown in FIG. 1, a lane departure suppression device 1 according to an embodiment of the present invention is applied to a vehicle V0 having an automatic driving function (hereinafter referred to as the "host vehicle"). When the lateral distance between the reference line BL extending in the extending direction of the lane (first lane L1) in which the host vehicle is traveling and the host vehicle is less than or equal to a threshold value in a state where the automatic driving function is disabled, the lane departure suppression device 1 has a function of executing lane departure suppression control for controlling the host vehicle so that the host vehicle is suppressed from deviating outside the reference line BL. Note that this control may be executed as one function of the automatic driving function.

[0016] (Specific Configuration) As shown in FIG. 1, the lane departure suppression device 1 includes an ECU 10, an in-vehicle sensor 20, a notification device 30, and a steering device 40.

[0017] The ECU10 includes a microcomputer equipped with a CPU10a, ROM10b, RAM10c, timer10d, etc. The ECU10 is connected to other ECUs in the vehicle via CAN (Controller Area Network).

[0018] The on-board sensor 20 includes a forward sensor that acquires information about a target located in front of the vehicle. Specifically, the on-board sensor 20 includes a millimeter-wave radar 21 and a camera 22 as forward sensors.

[0019] The millimeter-wave radar 21 includes a transmitting / receiving unit and a signal processing unit (not shown). The transmitting / receiving unit emits millimeter-wave radio waves (hereinafter referred to as "millimeter waves") in front of the vehicle and receives millimeter waves (reflected waves) reflected by three-dimensional objects (guardrails, poles, etc.) located within its radiation range. The signal processing unit calculates the distance and direction (angle α between the straight line connecting the transmitting / receiving unit and the three-dimensional object and the central axis of the area where the millimeter waves are emitted) between the vehicle and the three-dimensional object, based on the time taken from when the transmitting / receiving unit emitted the millimeter waves until the reflected waves were received, the phase difference between the transmitted millimeter waves and the received reflected waves, and the attenuation level of the reflected waves. The signal processing unit provides these calculation results to the ECU 10.

[0020] Camera 22 is equipped with an imaging device and an image analysis device. The imaging device incorporates a lens and an image sensor such as a CCD (charge coupled device) or CIS (CMOS image sensor). The imaging device is mounted on the upper part of the front windshield glass. Camera 22 is oriented forward. The imaging device captures the foreground of the vehicle at a predetermined frame rate and acquires image data. The imaging device transmits the image data to the image analysis device. The image analysis device analyzes the acquired image data and obtains information about targets located in front of the vehicle from the image. For example, the image analysis device identifies (recognizes) the type of target located in front of the vehicle (e.g., lane marks, zebra zones, etc.) and obtains (calculates) the position of each target image in the acquired image (coordinates such as representative positions (e.g., the top, bottom, left, and right edges of the target image)). The image analysis device provides the calculation results to the ECU 10.

[0021] In addition, the on-board sensor 20 includes a vehicle sensor that acquires information regarding the behavior (speed) of the vehicle itself. Specifically, the on-board sensor 20 includes a speed sensor 23 as a vehicle sensor.

[0022] The speed sensor 23 detects the rotational speed (wheel speed) of each wheel and calculates the vehicle's speed sp0 (measured value) based on the wheel speed. The speed sensor 23 provides the calculation result to the ECU 10.

[0023] The notification device 30 includes an image display device and an audio device. The image display device receives an image display command from the ECU 10 and displays a predetermined image in accordance with the command. The audio device also receives an audio playback command from the ECU 10 and plays a predetermined sound in accordance with the command.

[0024] The steering device 40 adjusts the steering angle θ of the vehicle's steering wheels. The steering device 40 includes a steering mechanism, an electric actuator, a steering ECU, etc. The steering mechanism includes a mechanism that converts the rotational motion of the steering wheel into lateral linear motion to rotate the knuckle arm around an axis. The electric actuator includes an electric motor that drives the steering mechanism. The steering ECU obtains a target value θt for the steering angle θ from another ECU. The steering ECU drives the electric actuator to match the steering angle θ to the target value θt.

[0025] (Lane departure prevention control) As described below, the ECU 10 sets a pair of left and right reference lines BL and BR, and controls predetermined devices of the vehicle to prevent the vehicle from deviating from the area between reference line BL and reference line BR. Specifically, when the vehicle approaches reference line BR or reference line BL to a certain extent, the ECU 10 controls the notification device 30 to provide predetermined information to the driver, and controls the steering device 40 to move the vehicle toward the lateral center of the first lane L1. In the following description, this control will be referred to as "lane departure prevention control".

[0026] Incidentally, consider a scenario where, within the first lane L1 in which your vehicle is traveling, there is a zebra zone ZR extending longitudinally (in the front-to-back direction) along its right edge, and / or a zebra zone ZL extending longitudinally along its left edge. Drivers who prefer to drive in a way that avoids entering zebra zones ZR and ZL are likely to expect that lane departure prevention control will be activated when their vehicle approaches zebra zones ZR and ZL to a certain extent.

[0027] However, it is conceivable that the driver may intentionally enter the zebra zones ZR and ZL (hereinafter referred to as the "specific scene"). For example, as shown in Figure 2, if a right-turn lane (second lane L2_R) is provided to the right of the area FR in front of the vehicle in the first lane L1, and a zebra zone ZR is provided before that right-turn lane, then the specific scene would be when the driver intentionally enters the zebra zone ZR when entering the right-turn lane from the first lane L1. Furthermore, as shown in Figure 3, for example, there is a main lane (second lane L2_L) extending parallel to the first lane L1, which serves as an acceleration lane, to the left of the first lane L1. A zebra zone ZL is provided before the area FL where it is possible to enter the second lane L2_L from the first lane L1. A specific scenario is when the driver intentionally enters the zebra zone ZR when entering the main lane from the first lane L1. Note that in Figure 3, the portion of the leftmost line L1L shown in practice is a white line or guardrail (row of poles) that the vehicle is prohibited from crossing. In these specific scenarios, if the ECU 10 executes lane departure prevention control when the vehicle approaches the zebra zones ZR and ZL to a certain extent, the driver may find this control bothersome.

[0028] Therefore, as described below, the ECU 10 selects either the rightmost line L1R (lane marking) of the first lane L1 shown in Figure 2 or the leftmost line ZRL of the zebra zone ZR as the reference line BR, depending on whether a predetermined condition XR is met or not. Also, the ECU 10 selects either the leftmost line L1L of the first lane L1 shown in Figure 3 or the rightmost line ZLR of the zebra zone ZL as the reference line BL, depending on whether a predetermined condition XL is met or not. Below, the process of selecting the rightmost reference line (i.e., reference line BR) among the processes executed by the ECU 10 will be described in detail. Note that in this explanation, the code of the component corresponding to the code of the various components (ZR, BR, XR, etc.) (ZL, BL, XL, etc.) will be enclosed in parentheses, and the explanation of the process of determining the leftmost reference line will be omitted.

[0029] The ECU 10 sequentially determines the presence or absence of zebra zones ZR(ZL) based on information acquired from the on-board sensor 20 (camera 22). If the ECU 10 determines that zebra zones ZR(ZL) exist, it determines whether condition XR(XL), which is used to determine that there is a high probability that the driver will intentionally enter the zebra zone ZR(ZL), is met. The ECU 10 determines that condition XR(XL) is met if conditions XR1(XL1) through XR4(XL4) are also met. [XR1(XL1)]...There exists a second lane L2_R(L2_L) that is located to the right (left) of the area in front of the vehicle (FR) in the first lane L1 and is connected to the right edge (left edge) of the first lane L1. [XR2(XL2)]... The vehicle is unable to enter the second lane L2_R(L2_L) until it reaches the area FR(FL) ahead, but can enter the second lane L2_R(L2_L) within area FR(FL). [XR3(XL3)]... The zebra zone ZR(ZL) extends to region FR(FL). [XR4(XL4)]...The predicted time ΔtR(ΔtL) required for the front end of the vehicle to reach area FR(FL) is less than or equal to the threshold ΔtRth(ΔtLth). The ECU 10 can determine the existence of the second lane L2_R(L2_L) based on the information acquired from the camera 22. Alternatively, road information (map information) may be acquired from a navigation system (not shown), and the existence of the second lane L2_R(L2_L) may be determined based on that information. The ECU 10 also acquires the time ΔtR(ΔtL) by dividing the distance DFR(DFL) from the vehicle's current location to area FR(FL) by the vehicle's speed sp0.

[0030] If ECU10 determines that there is no zebra zone ZR (ZL), it selects the rightmost line L1R (leftmost line L1L) as the reference line BR (reference line BL).

[0031] Furthermore, if a zebra zone ZR(ZL) exists and condition XR(XL) is not met, ECU10 selects the leftmost line ZRL (rightmost line ZLR) of the zebra zone ZR(ZL) as the reference line BR(BL).

[0032] On the other hand, if a zebra zone ZR(ZL) exists and condition XR(XL) is met, ECU10 selects the rightmost line L1R (leftmost line L1L) of the first lane L1 as the reference line BR(BL), rather than the leftmost line ZRL (rightmost line ZLR) of the zebra zone ZR(ZL).

[0033] The ECU10 then executes lane departure prevention control when the distance DR(DL) between the selected reference line BR(BL) and the right side (left side d) of the vehicle is less than or equal to the threshold Dth. In other words, when there is no zebra zone ZR(ZL), the ECU10 executes lane departure prevention control when the vehicle approaches the right edge (left edge) of the first lane L1 to a certain extent. Also, when there is a zebra zone ZR(ZL) and condition XR(XL) is not met (see Figure 4), the ECU10 executes lane departure prevention control when the vehicle approaches the zebra zone ZR(ZL) to a certain extent. On the other hand, when there is a zebra zone ZR(ZL) and condition XR(XL) is met, the ECU10 executes lane departure prevention control when the vehicle approaches the right edge line L1R (left edge line L1L) to a certain extent. In other words, in this case, lane departure prevention control is not performed during the process of the vehicle entering the zebra zone ZR (ZL).

[0034] Next, referring to Figure 5, we will explain the program PR1 executed by the CPU 10a (hereinafter simply referred to as "CPU") to realize the vehicle departure prevention function of the lane departure prevention device 1.

[0035] The CPU executes program PR1 at predetermined intervals when the vehicle's ignition switch is turned ON.

[0036] (Program PR1) The CPU starts executing program PR1 from step 100 and proceeds to step 101.

[0037] In step 101, the CPU determines whether or not the zebra zone ZR exists. If the CPU determines that the zebra zone ZR exists (101: Yes), it proceeds to step 102. On the other hand, if the XPU does not determine that the zebra zone ZR exists (101: No), it proceeds to step 103.

[0038] In step 102, the CPU determines whether condition XR is true or false. If the CPU determines that condition XR is true (102: Yes), it proceeds to step 103. On the other hand, if the CPU does not determine that condition XR is true (102: No), it proceeds to step 104.

[0039] In step 103, the CPU selects the rightmost line L1R of the first lane L1 as the reference line BR. Next, the CPU proceeds to step 105.

[0040] In step 104, the CPU selects the leftmost line ZRL of the zebra zone ZR as the reference line BR. The CPU then proceeds to step 105.

[0041] In step 105, the CPU determines whether or not the zebra zone ZL exists. If the CPU determines that the zebra zone ZL exists (105: Yes), it proceeds to step 106. On the other hand, if the XPU does not determine that the zebra zone ZL exists (105: No), it proceeds to step 107.

[0042] In step 106, the CPU determines whether condition XL is true or false. If the CPU determines that condition XL is true (106: Yes), it proceeds to step 107. On the other hand, if the CPU does not determine that condition XL is true (106: No), it proceeds to step 108.

[0043] In step 107, the CPU selects the leftmost line L1L of the first lane L1 as the reference line BL. Next, the CPU proceeds to step 109.

[0044] In step 108, the CPU selects the rightmost line ZLR of the zebra zone ZL as the reference line BL. Then, the CPU proceeds to step 109.

[0045] In step 109, the CPU determines whether either the distance DR between the right side of the vehicle and the reference line BR, or the distance DL between the left side of the vehicle and the reference line BL, is less than or equal to the threshold Dth. If the CPU determines that at least one of the distances DR and DL is less than or equal to the threshold Dth (109: Yes), it proceeds to step 110. On the other hand, if the CPU does not determine that at least one of the distances DR and DL is less than or equal to the threshold Dth (109: No), it proceeds to step 111.

[0046] In step 110, the CPU performs lane departure prevention control. The CPU then proceeds to step 111.

[0047] The CPU terminates the execution of program PR1 in step 111.

[0048] (effect) In the lane departure prevention device 1, the ECU 10 selects either the rightmost line L1R (leftmost line L1L) of the first lane L1 or the leftmost line ZRL (rightmost line ZLR) of the zebra zone ZR (ZL) as the reference line BR (BL), depending on whether condition X is met. Here, if conditions XR1 to XR4 (conditions XL1 to XL4) are met, there is a high probability that the driver of the vehicle will intentionally enter the zebra zone ZR (ZL). Therefore, if these conditions are met (if condition X is met), the ECU 10 selects the rightmost line L1R (leftmost line L1L) of the first lane L1 as the reference line BR (BL). On the other hand, if condition X is not met, the ECU 10 selects the leftmost line ZRL (rightmost line ZLR) of the zebra zone ZR (ZL) as the reference line BR (BL). In other words, the ECU 10 executes lane departure prevention control when the vehicle approaches the zebra zone ZR(ZL) to a certain extent (when the distance DR(DL) falls below the threshold DRth(DLth)) if the likelihood of the driver intentionally entering the zebra zone ZR(ZL) is low. On the other hand, if the ECU 10 is likely to intentionally enter the zebra zone ZR(ZL), it does not execute lane departure prevention control even when the vehicle approaches the zebra zone ZR(ZL) to a certain extent, but only when the vehicle enters the zebra zone ZR(ZL) and then approaches the right edge line L1R(L1L) of the first lane L1 to a certain extent. In this way, the lane departure prevention device 1 can provide driving assistance that meets the driver's expectations around the zebra zone ZR(ZL) (it can execute lane departure prevention control at an appropriate position).

[0049] (modified version) In the above embodiment, the lane departure prevention device 1 is configured such that condition XR4(XL4) is satisfied when the predicted time ΔtR(ΔtL) required for the front end of the vehicle to reach region FR(FL) is less than or equal to the threshold ΔtRth(ΔtLth). Alternatively, the lane departure prevention device 1 may be configured such that condition XR4(XL4) is satisfied when the distance DFR(DFL) is less than or equal to the threshold DFth. [Explanation of Symbols]

[0050] 1…Driving assistance system, 10…ECU, 20…On-board sensor, 30…Notification system, 40…Steering system

Claims

1. An on-board sensor that acquires information about an object located in front of the vehicle, A processor configured to perform lane departure suppression processing to control a predetermined device of a vehicle so as to prevent the vehicle from deviating outside the predetermined reference line when the lateral distance between the vehicle and a predetermined reference line extending in the direction of extension of the first lane in which the vehicle is traveling is below a threshold, wherein the processor is configured to select the lateral end of the first lane as the reference line when a zebra zone extending longitudinally along one lateral end of the first lane exists within the first lane and predetermined conditions are met, and when the zebra zone exists within the first lane and the predetermined conditions are not met, the processor is configured to select the lateral end of the zebra zone opposite to the lateral end of the first lane as the reference line. A lane departure prevention device equipped with, The aforementioned processor, To the side of the area in front of the vehicle in the first lane, there exists a second lane connected to one end of the first lane, The vehicle is unable to enter the second lane until it reaches the area ahead, and is able to enter the second lane within the area ahead. The zebra zone extends to the forward region, and A lane departure prevention device configured to determine that the predetermined conditions are met when the distance between the vehicle and the forward area is less than or equal to a threshold, or when the time it is predicted that the vehicle will need to reach the forward area is less than or equal to a threshold.

2. In the lane departure prevention device according to claim 1, The aforementioned second lane is either a right-turn lane or a left-turn lane. A lane departure prevention device in which the front end of the zebra zone is connected to the right-turn lane or the left-turn lane.

3. In the lane departure prevention device according to claim 1, A lane departure prevention device in which the first lane is an acceleration lane and the second lane is a main lane.

4. An information acquisition step to acquire information about a target located in front of the vehicle, A control step for executing a lane departure prevention process to control a predetermined device of a vehicle so as to prevent the vehicle from deviating outside the predetermined reference line when the lateral distance between the vehicle and a predetermined reference line extending in the direction of extension of the first lane in which the vehicle is traveling is less than or equal to a threshold, wherein the control step is configured to select the lateral end of the first lane as the reference line when a zebra zone extending longitudinally along one end of the first lane in the lateral direction exists within the first lane and predetermined conditions are met, and to select the lateral end of the zebra zone opposite to the lateral end of the first lane as the reference line when the zebra zone exists within the first lane and the predetermined conditions are not met, A method for preventing lane departure, including, The control step described above is: To the side of the area in front of the vehicle in the first lane, there exists a second lane connected to one end of the first lane, The vehicle is unable to enter the second lane until it reaches the area ahead, and is able to enter the second lane within the area ahead. The zebra zone extends to the forward region, and A lane departure prevention method configured to include the step of determining that the predetermined conditions are met when the distance between the vehicle and the forward area is less than or equal to a threshold, or when the time it is predicted that the vehicle will need to reach the forward area is less than or equal to a threshold.

5. The computer installed in the vehicle, An information acquisition step to acquire information about a target located in front of the vehicle, A control step for executing a lane departure prevention process to control a predetermined device of a vehicle so as to prevent the vehicle from deviating outside the predetermined reference line when the lateral distance between the vehicle and a predetermined reference line extending in the direction of extension of the first lane in which the vehicle is traveling is less than or equal to a threshold, wherein the control step is configured to select the lateral end of the first lane as the reference line when a zebra zone extending longitudinally along one end of the first lane in the lateral direction exists within the first lane and predetermined conditions are met, and to select the lateral end of the zebra zone opposite to the lateral end of the first lane as the reference line when the zebra zone exists within the first lane and the predetermined conditions are not met, A lane departure prevention program that performs the following actions: The control step described above is: To the side of the area in front of the vehicle in the first lane, there exists a second lane connected to one end of the first lane, The vehicle is unable to enter the second lane until it reaches the area ahead, and is able to enter the second lane within the area ahead. The zebra zone extends to the forward region, and A lane departure prevention program configured to include a step of determining that the predetermined conditions are met when the distance between the vehicle and the forward area is less than or equal to a threshold, or when the time it is predicted that the vehicle will need to reach the forward area is less than or equal to a threshold.

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