Traveling assistance device

Abstract

The present invention is to perform steering control according to the situation of the adjacent lane. The travel assist device of the present invention has at least one sensor (140) that acquires vehicle surrounding information, and at least one processor configured to perform determination processing that determines whether the current situation is a first situation or a second situation based on the vehicle surrounding information, and perform steering control that causes the host vehicle to travel along a target trajectory (TL) based on the result of the determination processing. The first situation is a situation in which the host vehicle overtakes a first other vehicle traveling in a first adjacent lane. The second situation is a situation in which the host vehicle is overtaken by the first other vehicle traveling in the first adjacent lane.

Description

Technical Field

[0001] This disclosure relates to a driving assistance device. Background Technology

[0002] Previously, driving assistance devices configured to perform steering control based on the vehicle's surrounding conditions have been proposed (for example, see Patent Document 1). Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2010-006271 Summary of the Invention The problem that the invention aims to solve

[0004] From now on, vehicles equipped with the aforementioned driving assistance devices will be referred to as "this vehicle," and vehicles existing around this vehicle will be referred to as "other vehicles." In addition, the lane in which this vehicle travels will be referred to as "this lane," and the lane adjacent to this lane will be referred to as "adjacent lane."

[0005] For example, there might be a situation where another vehicle is traveling in an adjacent lane, and this vehicle overtakes that other vehicle. In this situation, the distance between this vehicle and other vehicles decreases, which could make the driver of this vehicle feel uneasy. However, the driving assistance device in Patent Document 1 does not address the handling of this situation. Furthermore, the aforementioned problems may also occur when this vehicle is overtaken by another vehicle.

[0006] This disclosure provides a driving assistance device capable of performing steering control according to the aforementioned conditions. Methods for solving problems

[0007] In one or more embodiments, a driving assistance device is provided. The driving assistance device includes: at least one sensor that acquires vehicle perimeter information related to the surrounding area of ​​the vehicle; and at least one processor configured to, based on the vehicle perimeter information, perform a determination process to determine whether the current situation is a first situation or a second situation, and based on the result of the determination process, perform steering control to cause the vehicle to travel along a target trajectory. The first situation is when the vehicle overtakes a first other vehicle traveling in a first adjacent lane adjacent to the lane in which the vehicle is traveling. The second situation is when the vehicle is overtaken by the first other vehicle. Invention Effects

[0008] According to the above structure, the driving assistance device can perform steering control depending on whether the current situation is a first situation or a second situation. Other issues, structures, and effects beyond the above will become clear through the following description of embodiments. Attached Figure Description

[0009] Figure 1 This is a diagram showing the structure of a driving assistance device. Figure 2 This is a diagram showing the structure of the driving assistance ECU. Figure 3 This is a diagram used to illustrate lane keeping control as an example of steering control. Figure 4 This diagram represents the situation where the vehicle overtakes the first adjacent vehicle traveling in the first adjacent lane (the first situation). Figure 5 This is an example of a mapping used to determine the correction value dc for the lateral position of the vehicle. Figure 6 This diagram illustrates a situation where the vehicle is overtaken by a vehicle traveling in the first adjacent lane (the second situation). Figure 7 This is a flowchart executed by the driving assistance ECU in Example 1. Figure 8 This is a flowchart executed by the driving assistance ECU in Example 1. Figure 9 This diagram illustrates an example where, under the first condition, there is no second adjacent vehicle in the second adjacent lane. Figure 10 This diagram illustrates an example where a second adjacent vehicle exists in the second adjacent lane under the first condition. Figure 11 This diagram illustrates an example where a second adjacent vehicle exists in the second adjacent lane under the first condition. Figure 12 This diagram illustrates an example where a second adjacent vehicle exists in the second adjacent lane under the first condition. Figure 13 This is an example of a mapping diagram used in Example 2 to determine the correction value dc for the lateral position of the vehicle. Figure 14 This is a flowchart executed by the driving assistance ECU in Example 2. Figure 15 This is an example of a mapping used to find the correction rate Rc multiplied by the correction value dc. Figure 16 This is a flowchart executed by the driving assistance ECU in Example 4. Figure 17 This diagram illustrates an example where, in the first situation, there are other vehicles in front of the first adjacent vehicle. Figure 18 This is a flowchart executed by the driving assistance ECU in Example 6. Figure 19It is a diagram used to illustrate the distance Dy between the first adjacent vehicle and the dividing line representing the boundary between the current lane and the first adjacent lane. Figure 20 It is a table used to calculate reliability DR, and it is a table that shows the relationship between distance Dy and the addition / subtraction values. Figure 21 It is a table used to calculate reliability DR, and it is a table that shows the relationship between the distance Dx between the current vehicle and the first adjacent vehicle in the front-rear direction and the addition / subtraction operation value. Figure 22 This is a diagram representing the first region used to determine the first condition. Figure 23 This is a diagram representing a second area used to determine, under a first condition, whether a second adjacent vehicle exists in the second adjacent lane. Detailed Implementation

[0010] Several embodiments of the driving assistance device will be described with reference to the accompanying drawings. The drawings illustrate specific structures but are not intended to limit the scope of this disclosure.

[0011] The following explanation uses lane keeping control as an example of steering control. From now on, lane keeping control will be referred to as "LK control".

[0012] <Example 1> (Structure of driving assistance device) Figure 1 This is a diagram showing the structure of the driving assistance device. The driving assistance device is mounted on the vehicle (this vehicle) VA. The driving assistance device includes a driving assistance ECU 110, a steering ECU 120, a steering actuator 130, vehicle peripheral sensors 140, and a vehicle speed sensor 150.

[0013] Figure 2 This diagram illustrates the structure of the driving assistance ECU 110. ECU is short for Electronic Control Unit, which is an electronic control circuit with a microcomputer as a component. The driving assistance ECU 110 includes a CPU 210, a memory 220, a non-volatile memory 230, and an interface 240, etc.

[0014] CPU 210 includes at least one processor and / or circuitry. Memory 220 includes, for example, RAM. Non-volatile memory 230 includes, for example, flash memory and ROM. CPU 210 uses memory 220 as its working memory to execute program code (instructions) stored in non-volatile memory 230. Thus, CPU 210 is able to perform the processes described later. Furthermore, steering ECU 120 also has the same structure.

[0015] Steering actuator 130 is assembled into the steering mechanism of vehicle VA. For example, steering actuator 130 includes an electric motor for steering the steering wheels (left front wheel and right front wheel) of vehicle VA. Steering actuator 130 is configured to control the steering wheels according to instructions from steering ECU 120.

[0016] Furthermore, the driving assistance ECU 110 and the steering ECU 120 can be integrated into a single ECU. Moreover, more than one ECU can be added to perform the processing described below.

[0017] The vehicle perimeter sensor 140 acquires vehicle perimeter information related to the area surrounding the vehicle VA. The area surrounding the vehicle VA includes the area in front of the vehicle VA, the area to the right, the area to the left, and the area behind the vehicle VA.

[0018] Vehicle perimeter information includes object information related to objects existing in the area surrounding the vehicle (VA), and boundary line information related to the dividing lines (white lines) existing in the area surrounding the vehicle (VA). Objects include moving objects such as vehicles and pedestrians, as well as stationary objects such as guardrails and fences. Object information includes, for example, the distance between the vehicle (VA) and the object, the object's direction of movement relative to the vehicle (VA), the object's orientation relative to the vehicle (VA), the object's relative speed relative to the vehicle (VA), and the type of object (e.g., whether the object is moving or stationary). Boundary line information includes the positions of multiple dividing lines defining lanes (channels), and parameters related to the dividing lines. Parameters related to the dividing lines include the curvature of the dividing lines, the lateral position of the vehicle (VA) relative to the dividing lines (position in the road width direction), and the yaw angle of the vehicle (VA) relative to the dividing lines.

[0019] For example, the vehicle perimeter sensor 140 can be one or a combination of radar sensors, camera sensors, LiDAR, etc. The vehicle perimeter sensor 140 can also be other sensors, as long as it can acquire the aforementioned object information and boundary line information.

[0020] The vehicle speed sensor 150 acquires information related to the vehicle's speed Va.

[0021] (LK control) Figure 3This diagram illustrates LK control as an example of steering control. The driving assistance ECU 110 detects the left dividing line LL and the right dividing line RL based on vehicle perimeter information (road marking information). The driving assistance ECU 110 identifies the area between the left dividing line LL and the right dividing line RL as the area where the vehicle VA should travel (i.e., the lane). The driving assistance ECU 110 sets the line connecting the center position of the road width direction between the left dividing line LL and the right dividing line RL as the center line Lc. Then, the driving assistance ECU 110 sets the center line Lc as the target trajectory TL for LK control. The driving assistance ECU 110 calculates a steering control quantity (e.g., steering torque) to make the vehicle VA travel along the target trajectory TL. The driving assistance ECU 110 outputs the steering control quantity to the steering ECU 120. The steering ECU 120 controls the steering actuator 130 based on the steering control quantity.

[0022] Next, several situations that may arise during the execution of LK control will be explained. Furthermore, the vehicle VA equipped with the driving assistance device will be referred to as "this vehicle VA" below. The lane in which this vehicle VA travels will be referred to as "this lane Ln0", the lane adjacent to the left of this lane Ln0 will be referred to as "first adjacent lane Ln1", and the lane adjacent to the right of this lane Ln0 will be referred to as "second adjacent lane Ln2". Other vehicles traveling in the first adjacent lane Ln1 or the second adjacent lane Ln2 will be referred to as "adjacent vehicles".

[0023] (Steering control in the first situation) Figure 4 This diagram illustrates a situation where the first adjacent vehicle OV1 is traveling in the first adjacent lane Ln1, and the present vehicle VA overtakes the first adjacent vehicle OV1. Hereinafter, this situation will be referred to as the "first situation".

[0024] In the first scenario, vehicle VA gradually approaches the first adjacent vehicle OV1. Since the driver of vehicle VA has identified the first adjacent vehicle OV1, the driver feels uneasy as vehicle VA passes beside the first adjacent vehicle OV1. Considering this, the driving assistance ECU 110 modifies the elements of LK control (hereinafter referred to as "control elements"). Here, control elements refer to the various processes used to perform LK control, and the parameters used in these processes. Specifically, control elements include the target trajectory TL, which serves as the reference for LK control, and the control gain used for the steering control quantity of LK control, etc. In this example, the control element is the target trajectory TL.

[0025] In the first scenario, the driving assistance ECU 110 calculates the line Lofs that is far from the first adjacent lane Ln1. To do this, the driving assistance ECU 110 calculates a correction value dc for the lateral position of the vehicle VA relative to the center line Lc. Here, the lateral position of the vehicle VA refers to its position in the road width direction within lane Ln0. The line Lofs is obtained by offsetting it to the right relative to the center line Lc by the correction value dc.

[0026] Figure 5 This is the mapping MP1 used to calculate the correction value dc. Mapping MP1 defines the relationship between the vehicle VA's longitudinal distance Dx and the first adjacent vehicle OV1 and the correction value dc. A negative distance Dx means the vehicle VA is behind the first adjacent vehicle OV1. A zero distance Dx means the vehicle VA is directly next to the first adjacent vehicle OV1. A positive distance Dx means the vehicle VA is in front of the first adjacent vehicle OV1. A positive correction value dc means the lateral position of the vehicle VA is shifted to the left relative to the centerline Lc. Conversely, a negative correction value dc means the lateral position of the vehicle VA is shifted to the right relative to the centerline Lc. Therefore, mapping MP1 is a mapping that shifts the lateral position of the vehicle VA to the right relative to the centerline Lc.

[0027] The driving assistance ECU 110 calculates a correction value dc based on the mapping map MP1. According to the mapping map MP1, if the vehicle VA approaches the first adjacent vehicle OV1 (the absolute value of the distance Dx decreases), the correction value dc becomes a negative predetermined value dc1 (e.g., -0.4m). That is, the vehicle VA leaves the first adjacent lane Ln1. Subsequently, the vehicle VA overtakes the first adjacent vehicle OV1. Accompanying this, the correction value dc gradually approaches zero, eventually becoming zero. That is, the lateral position of the vehicle VA returns to the center line Lc. Furthermore, the value dc1 can also be appropriately changed to ensure that the vehicle VA does not deviate from its lane Ln0.

[0028] The driving assistance ECU 110 sets the line Lofs as the target trajectory TL. The driving assistance ECU 110 calculates the steering control quantity to make the vehicle VA travel along the target trajectory TL. The driving assistance ECU 110 outputs the steering control quantity to the steering ECU 120. According to this structure, even if a first situation occurs during the execution of LK control, the driving assistance ECU 110 executes the first control, thus allowing the vehicle VA to pass to the right of the first adjacent vehicle OV1 with a larger gap relative to it. This reduces the possibility of driver anxiety. Furthermore, the driving assistance ECU 110 uses the mapping map MP1 to gradually change the correction value dc according to the distance Dx. According to this structure, the lateral position of the vehicle VA can change smoothly according to the distance Dx.

[0029] The steering control performed under the first condition (i.e., the steering control that uses lines Lofs as the target trajectory TL) will then be referred to as the "first control".

[0030] Furthermore, in order to initiate first control, the driving assistance ECU 110 determines a first start condition based on vehicle surrounding information. The first start condition is used to determine whether the current situation is the first situation. Specifically, the first start condition is established when both conditions A1 and A2 are met. In addition, condition A2 can also be changed to a condition related to the inter-vehicle time between the current vehicle VA and the first adjacent vehicle OV1. (Condition A1): The speed Va of this vehicle VA is greater than the speed V1 of the first adjacent vehicle OV1. (Condition A2): Distance Dx ≥ First distance threshold Dxth1 (specified negative value)

[0031] Furthermore, in order to terminate the first control, the driving assistance ECU 110 determines a first termination condition based on vehicle surrounding information. The first termination condition is used to determine whether the vehicle VA has completed overtaking the first adjacent vehicle OV1. Specifically, the first termination condition is established when condition B1 is met. In addition, condition B1 can also be changed to a condition related to the inter-vehicle time between the vehicle VA and the first adjacent vehicle OV1. (Condition B1): Distance Dx ≥ second distance threshold Dxth2 (a specified positive value)

[0032] (Steering control in the second situation) Figure 6 This diagram illustrates a situation where the first adjacent vehicle OV1 is traveling in the first adjacent lane Ln1, and the current vehicle VA is overtaken by the first adjacent vehicle OV1. This situation will henceforth be referred to as the "second situation".

[0033] In the second scenario, the first adjacent vehicle OV1 gradually approaches the vehicle VA. However, since the first adjacent vehicle OV1 is located behind the vehicle VA, in most cases, the driver of the vehicle VA cannot recognize the first adjacent vehicle OV1. In this second scenario, it is assumed that the driving assistance ECU 110 executes the first control. In this situation, the driver will feel that the vehicle VA suddenly moves to the right, which may cause the driver to feel uneasy. Considering this, the driving assistance ECU 110 executes steering control in the second scenario, using the center line Lc as the target trajectory TL. The driving assistance ECU 110 sets the center line Lc as the target trajectory TL. The driving assistance ECU 110 calculates the steering control quantity to make the vehicle VA travel along the target trajectory TL. The driving assistance ECU 110 outputs the steering control quantity to the steering ECU 120. According to this structure, even if the second scenario occurs during the execution of LK control, the driving assistance ECU 110 executes the second control, so the vehicle VA will not move laterally. This reduces the possibility of driver unease.

[0034] The steering control that will be performed in the second situation (i.e., steering control using the centerline Lc as the target trajectory TL) will then be referred to as the "second control".

[0035] Furthermore, in order to initiate the second control, the driving assistance ECU 110 determines a second start condition based on vehicle surrounding information. The second start condition is used to determine whether the current situation is a second situation. Specifically, the second start condition is established when both conditions C1 and C2 are met. In addition, condition C2 can also be changed to a condition related to the inter-vehicle time between the current vehicle VA and the first adjacent vehicle OV1. (Condition C1): The speed Va of this vehicle VA is less than the speed V1 of the first adjacent vehicle OV1. (Condition C2): Distance Dx ≤ third distance threshold Dxth3 (a specified positive value)

[0036] Furthermore, in order to terminate the second control, the driving assistance ECU 110 determines a second termination condition based on vehicle surrounding information. The second termination condition is used to determine whether the first adjacent vehicle OV1 has completed overtaking the current vehicle VA. Specifically, the second termination condition is established when condition D1 is met. In addition, condition D1 can also be changed to a condition related to the inter-vehicle time between the current vehicle VA and the first adjacent vehicle OV1. (Condition D1): Distance Dx ≤ fourth distance threshold Dxth4 (a specified negative value)

[0037] (Steering control under normal conditions) Subsequently, the situation that is neither the first situation nor the second situation is referred to as the "normal situation". Under the normal situation, the driving assistance ECU 110 executes steering control using the centerline Lc as the target trajectory TL. Specifically, the driving assistance ECU 110 sets the centerline Lc as the target trajectory TL. The driving assistance ECU 110 calculates the steering control quantity used to make the vehicle VA travel along the target trajectory TL. The driving assistance ECU 110 outputs the steering control quantity to the steering ECU 120.

[0038] The steering control performed under normal conditions (i.e., control that uses the centerline Lc as the target trajectory TL) is called "normal control".

[0039] (Processing flow) Figure 7 and Figure 8 This is a flowchart illustrating the routine executed by the driving assistance ECU 110 in Embodiment 1. The driving assistance ECU 110 executes repeatedly at a predetermined period dT (e.g., 50ms). Figure 7 and Figure 8 The following are the routines. The processing flow for "normal situation", "first situation" and "second situation" are explained respectively.

[0040] • Normal situation The driving assistance ECU 110 reads the vehicle's surrounding information (step 701). The driving assistance ECU 110 detects adjacent vehicles based on the vehicle's surrounding information (step 702). Furthermore, since the current situation is normal, the driving assistance ECU 110 does not detect adjacent vehicles.

[0041] The driving assistance ECU 110 determines whether the first flag Flg1 is "1" (step 703). If the first flag Flg1 is "1", it means that the current situation is the first situation. If the first flag Flg1 is "0", it means that the current situation is not the first situation. Now, assuming that the first flag Flg1 is "0", the driving assistance ECU 110 determines "no" and proceeds to step 704.

[0042] The driving assistance ECU 110 determines whether the second flag Flg2 is "1" (step 704). If the second flag Flg2 is "1", it means that the current situation is the second situation. If the second flag Flg2 is "0", it means that the current situation is not the second situation. Now, assuming that the second flag Flg2 is "0", the driving assistance ECU 110 determines "no" and proceeds to step 705.

[0043] The driving assistance ECU 110 determines whether there is an adjacent vehicle behind the current vehicle VA (step 705). Under normal circumstances, the driving assistance ECU 110 determines "no" and proceeds to step 711 (from...). Figure 7 B enters Figure 8 (B) The driving assistance ECU 110 determines whether there is an adjacent vehicle in front of the vehicle VA (step 711). If the driving assistance ECU 110 determines "no", proceed to step 717. The driving assistance ECU 110 performs normal control as described above. The driving assistance ECU 110 sets the center line Lc as the target trajectory TL (step 717). Next, the driving assistance ECU 110 performs smoothing processing on the target trajectory TL (step 718). Smoothing processing is a process to make the target trajectory TL a smooth curve without generating steps in the target trajectory TL. Then, the driving assistance ECU 110 performs steering control (step 719). Specifically, the driving assistance ECU 110 calculates the steering control quantity for making the vehicle VA travel along the target trajectory TL. The driving assistance ECU 110 outputs the steering control quantity to the steering ECU 120. The steering ECU 120 controls the steering actuator 130 based on the steering control quantity.

[0044] First situation Suppose the current situation becomes Figure 4 In this situation, vehicle VA attempts to overtake the first adjacent vehicle OV1. In this case, driving assistance ECU 110 executes steps 701, 702, 703 and 704, and then proceeds to step 705.

[0045] In addition, the driving assistance ECU 110 may also, in step 702, treat adjacent vehicles that meet the following conditions E1 or E2 as the target vehicles for processing as described later. (Condition E1): The distance between this vehicle VA and the adjacent vehicle in the road width direction is less than the specified distance. (Condition E2): The distance between the dividing line of this lane Ln0 and the adjacent vehicle in the road width direction shall be less than the specified distance. This is for the following reasons. For example, if the distance between vehicle VA and adjacent vehicles in the road width direction is relatively large, the driver of vehicle VA is less likely to feel uneasy even if vehicle VA passes next to adjacent vehicles.

[0046] In step 705, the driving assistance ECU 110 determines "No" and proceeds to step 711 (from...). Figure 7 B enters Figure 8(B). The driving assistance ECU 110 determines whether there is an adjacent vehicle in front of the vehicle VA (step 711). The driving assistance ECU 110 determines "yes" and proceeds to step 712.

[0047] The driving assistance ECU 110 determines whether the first start condition is met (step 712). If the first start condition is not met, the driving assistance ECU 110 determines "no" and proceeds to step 717 (in... Figure 8 (From D to D). The driving assistance ECU 110 performs normal control as described above.

[0048] exist Figure 4 Under the current conditions, the first starting condition is met. Therefore, the driving assistance ECU 110 determines "yes" and proceeds to step 713. The driving assistance ECU 110 sets the first flag Flg1 to "1" (step 713). Then, the driving assistance ECU 110 performs first control. The driving assistance ECU 110 uses the mapping map MP1 to calculate the lines Lofs as described above. The driving assistance ECU 110 sets the lines Lofs as the target trajectory TL (step 714). Next, the driving assistance ECU 110 performs smoothing processing on the target trajectory TL (step 718). Then, the driving assistance ECU 110 performs steering control (step 719).

[0049] Afterwards, the driving assistance ECU 110 executes steps 701 and 702, and then proceeds to step 703. The driving assistance ECU 110 determines "yes" and proceeds to step 715 (from...). Figure 7 A enters Figure 8 (A).

[0050] The driving assistance ECU 110 determines whether the first termination condition is met (step 715). If the first termination condition is not met, the driving assistance ECU 110 continues the first control. That is, if the driving assistance ECU 110 determines "no", steps 714, 718, and 719 are executed.

[0051] If the first termination condition is met, the driving assistance ECU 110 determines "yes" and proceeds to step 716. The driving assistance ECU 110 sets the first flag Flg1 to "0" (step 716). The driving assistance ECU 110 terminates the first control and executes normal control. The driving assistance ECU 110 sets the center line Lc to the target trajectory TL (step 717). Next, the driving assistance ECU 110 performs smoothing processing on the target trajectory TL (step 718). Then, the driving assistance ECU 110 executes steering control (step 719).

[0052] Second situation Suppose the current situation becomes Figure 6In the situation where the first adjacent vehicle OV1 attempts to overtake vehicle VA, the driving assistance ECU 110 executes steps 701, 702, 703, and 704, and then proceeds to step 705. The driving assistance ECU 110 determines "yes" and proceeds to step 706.

[0053] The driving assistance ECU 110 determines whether the second start condition is met (step 706). If the second start condition is not met, the driving assistance ECU 110 determines "no" and proceeds to step 717 (from...). Figure 7 D enters Figure 8 (D). The driving assistance ECU110 performs normal control as described above.

[0054] exist Figure 6 Under these conditions, the second starting condition is met. Therefore, the driving assistance ECU 110 determines "yes" and proceeds to step 707. The driving assistance ECU 110 sets the second flag Flg2 to "1" (step 707). Then, the driving assistance ECU 110 executes the second control. The driving assistance ECU 110 proceeds to step 710 (from... Figure 7 C enters Figure 8 (C). The driving assistance ECU 110 sets the center line Lc as the target trajectory TL (step 710). The driving assistance ECU 110 performs smoothing processing on the target trajectory TL (step 718). Then, the driving assistance ECU 110 performs steering control (step 719).

[0055] Then, the driving assistance ECU 110 executes steps 701, 702, and 703, and then proceeds to step 704. The driving assistance ECU 110 determines "yes" and proceeds to step 708.

[0056] The driving assistance ECU 110 determines whether the second termination condition is met (step 708). If the second termination condition is not met, the driving assistance ECU 110 continues the second control. That is, if the driving assistance ECU 110 determines "no", it proceeds to step 710 (from...). Figure 7 C enters Figure 8 (C).

[0057] If the second termination condition is met, the driving assistance ECU 110 determines "yes" and proceeds to step 709. The driving assistance ECU 110 sets the second flag Flg2 to "0" (step 709). Therefore, the driving assistance ECU 110 terminates the second control and executes normal control. The driving assistance ECU 110 proceeds to step 717 (from...). Figure 7 D enters Figure 8(D). The driving assistance ECU 110 sets the center line Lc as the target trajectory TL (step 717). Next, the driving assistance ECU 110 performs smoothing processing on the target trajectory TL (step 718). Then, the driving assistance ECU 110 performs steering control (step 719).

[0058] (Effect) Based on the above structure, the driving assistance ECU 110 performs a determination process to classify the current situation as either a first situation or a second situation based on information about the vehicle's surroundings. Based on the result of this determination process, it performs steering control to guide the vehicle VA along the target trajectory TL. The driving assistance ECU 110 sets (or changes) the target trajectory TL according to the determined situation (first situation or second situation), thereby controlling the lateral position of the vehicle VA. This improves the driver's sense of security.

[0059] (Modified Example) The driving assistance ECU 110 can set the control gain of the steering control used in the second situation to be greater than the control gain used in situations other than the second situation. In this configuration, in the second situation, when the driver of the vehicle VA operates the steering wheel, the driving assistance ECU 110 applies a large torque to the steering mechanism to return the lateral position of the vehicle VA to the target trajectory TL. Therefore, the driver experiences a large load on the steering wheel operation. Consequently, the lateral position of the vehicle VA is easily maintained on the target trajectory TL (centerline Lc). This prevents the vehicle VA from approaching the first adjacent vehicle OV1 traveling from behind the vehicle VA.

[0060] <Example 2> use Figures 9-11 The structure of Example 2 is explained. In the first situation, there is a second adjacent vehicle OV2 traveling in the second adjacent lane Ln2. The driving assistance ECU 110 changes the correction value dc according to the following situations a to d.

[0061] exist Figure 9 In the example, vehicle VA attempts to overtake the first adjacent vehicle OV1. That is, the current situation is situation one. On the other hand, there is no adjacent vehicle in the second adjacent lane Ln2. This situation will be referred to as "situation a". In situation a, the driving assistance ECU 110... Figure 13The mapping MP1 shown calculates the correction value dc. The minimum value of the correction value dc in mapping MP1 is "dc1 (e.g., -0.4m)". Therefore, the driving assistance ECU 110 calculates the line Lofs, which is offset to the right by "dc1" relative to the center line Lc. The driving assistance ECU 110 sets the line Lofs as the target trajectory TL. In case a, since sufficient distance is ensured between the vehicle VA and the first adjacent vehicle OV1, the driver's sense of security is improved.

[0062] Figure 10 Similarly, vehicle VA attempts to overtake the first adjacent vehicle OV1. The second adjacent vehicle OV2 is traveling in the second adjacent lane Ln2. Although the second adjacent vehicle OV2 attempts to overtake vehicle VA, the distance between vehicle VA and the second adjacent vehicle OV2 in the longitudinal direction is relatively large (i.e., larger than the prescribed distance). This situation will be referred to as "Situation b". In Situation b, the driving assistance ECU 110... Figure 13 The correction value dc is calculated from the mapping MP2 shown. The minimum value of the correction value dc in the mapping MP2 is "dc2 (e.g., -0.2m)". Here, dc2 > dc1. The driving assistance ECU 110 calculates the line Lofs, which is offset to the right by "dc2" relative to the center line Lc. The driving assistance ECU 110 sets the line Lofs as the target trajectory TL. In case b, considering the second adjacent vehicle OV2 approaching from behind the vehicle VA, the correction value dc is smaller than in case a. Therefore, the driver's sense of security can be improved.

[0063] Figure 11 Similarly, in an example, vehicle VA attempts to overtake the first adjacent vehicle OV1, and the second adjacent vehicle OV2 attempts to overtake vehicle VA. The ratio of the distance between vehicle VA and the second adjacent vehicle OV2 in the longitudinal direction is... Figure 10 The example is small. This situation will be referred to as "Situation C" from now on. In Situation C, the driving assistance ECU 110... Figure 13 The mapping MP3 shown yields the correction value dc. The minimum correction value dc in the mapping MP3 is "dc3 (e.g., -0.1m)". Here, dc3 > dc2. The driving assistance ECU 110 calculates the line Lofs, which is offset to the right by "dc3" relative to the center line Lc. The driving assistance ECU 110 sets the line Lofs as the target trajectory TL. In case c, the correction value dc is smaller than in case b. Therefore, the driver's sense of security can be improved.

[0064] Figure 12Similarly, in another example, vehicle VA attempts to overtake the first adjacent vehicle OV1, and the second adjacent vehicle OV2 attempts to overtake vehicle VA. The distance between vehicle VA and the second adjacent vehicle OV2 in the longitudinal direction is zero. That is, the second adjacent vehicle OV2 attempts to pass next to vehicle VA. This situation will be referred to as "situation d". In situation d, the driving assistance ECU 110... Figure 13 The correction value dc is calculated from the mapping MP4 shown. The minimum value of the correction value dc in the mapping MP4 is "dc4 (e.g., -0.05m)". Here, dc4 > dc3. The driving assistance ECU 110 calculates the line Lofs, which is offset to the right by "dc4" relative to the center line Lc. The driving assistance ECU 110 sets the line Lofs as the target trajectory TL. In case d, the correction value dc is smaller than in case c. Therefore, the driver's sense of security can be improved. Furthermore, in case d, dc4 can also be zero. In this case, the driving assistance ECU 110 sets the center line Lc as the target trajectory TL. The lateral position of the vehicle VA is maintained at the center line Lc, thus further improving the driver's sense of security.

[0065] (Processing flow) Figure 14 This is a flowchart illustrating the routine executed by the driving assistance ECU 110 in Embodiment 2. The driving assistance ECU 110 executes... Figure 14 Replace with routines Figure 8 The routine. Figure 14 routines and Figure 8 The difference in the routine is the addition of steps 1401-1405. Furthermore, for... Figure 8 The same steps are followed, the same symbols are assigned, and their descriptions are omitted.

[0066] When the first starting condition is met, the driving assistance ECU 110 determines "yes" in step 712 and sets the first flag Flg1 to "1" (step 713). Next, the driving assistance ECU 110 determines, based on the vehicle's surrounding information, which of the following conditions (a to d) the current situation falls under (step 1401).

[0067] In case a, the driving assistance ECU 110 selects map MP1 (step 1402). In case b, the driving assistance ECU 110 selects map MP2 (step 1403). In case c, the driving assistance ECU 110 selects map MP3 (step 1404). In case d, the driving assistance ECU 110 selects map MP4 (step 1405).

[0068] Subsequently, the driving assistance ECU 110 uses the selected mapping map to calculate the line Lofs and sets the line Lofs as the target trajectory TL (step 714). The subsequent processing (steps 718 and 719) is similar to... Figure 8 same.

[0069] (Effect) Based on the above structure, the driving assistance ECU 110 determines whether a second adjacent vehicle OV2 exists in the second adjacent lane Ln2. If a second adjacent vehicle OV2 exists, the correction value dc is changed. Specifically, the smaller the absolute value of the distance between the current vehicle VA and the second adjacent vehicle OV2 in the longitudinal direction, the smaller the absolute value of the correction value dc. Therefore, the driver's sense of security can be improved.

[0070] (Modified Example) Furthermore, the driving assistance ECU 110 can also be configured to proceed to step 1401 if the determination in step 715 is "no". In this case, the driving assistance ECU 110 can appropriately select any one of the mapping maps MP1 to MP4 based on the change in the relationship between the current vehicle VA and the second adjacent vehicle OV2.

[0071] In the first control, the driving assistance ECU 110 can set the control gain of the steering control to be greater when a second adjacent vehicle OV2 is present in the second adjacent lane Ln2 (e.g., case b, case c, or case d) than when no second adjacent vehicle OV2 is present in the second adjacent lane Ln2 (case a). In this configuration, for example in case d, when the driver of the vehicle VA operates the steering wheel, the driving assistance ECU 110 applies a large torque to the steering mechanism to return the lateral position of the vehicle VA to the target trajectory TL. Therefore, the driver experiences a large load on the steering wheel operation. Consequently, the lateral position of the vehicle VA is easily maintained on the target trajectory TL. This prevents the vehicle VA from approaching the second adjacent vehicle OV2.

[0072] <Example 3> use Figure 15 The structure of Example 3 is explained. Figure 15 MP5 is a mapping used to calculate the correction rate Rc multiplied by the correction value dc1. In the first case, the driving assistance ECU 110 calculates the final correction value dc (dc = dc1 × Rc) of the lateral position of the vehicle VA by multiplying the correction value dc1 (e.g., -0.4m) by the correction rate Rc.

[0073] Mapping MP5 defines the relationship between the inter-vehicle time Tin and the correction rate Rc between the current vehicle VA and the first adjacent vehicle OV1. The driving assistance ECU 110 calculates the inter-vehicle time Tin based on the relative speed and distance Dx of the first adjacent vehicle OV1 relative to the current vehicle VA. When the inter-vehicle time Tin is 5 seconds, this means that the current vehicle VA is located relatively far behind the first adjacent vehicle OV1. Therefore, the correction rate Rc is 0%. In this case, the driving assistance ECU 110 travels along the centerline Lc. If the inter-vehicle time Tin decreases, the correction rate Rc increases. That is, the closer the current vehicle VA is to the first adjacent vehicle OV1, the larger the final correction value dc (absolute value).

[0074] (Processing flow) The driving assistance ECU 110 in Example 3 executes Figure 7 and Figure 8 The routine is as described in Example 1. However, the processing in step 714 differs from that in Example 1. In step 714, the driving assistance ECU 110 uses the mapping map MP5 to calculate the correction rate Rc. The driving assistance ECU 110 calculates the final correction value dc by multiplying the correction value dc1 by the correction rate Rc. The driving assistance ECU 110 uses the correction value dc to calculate the line Lofs and sets the line Lofs as the target trajectory TL.

[0075] (Effect) According to the above structure, the driving assistance ECU 110 can shift the lateral position of the vehicle VA to the right relative to the centerline Lc based on the inter-vehicle time Tin. The vehicle VA passes to the right of the first adjacent vehicle OV1 with a larger gap relative to OV1. This reduces the possibility of driver anxiety. Furthermore, the driving assistance ECU 110 uses a mapping map MP5 to gradually change the correction value dc according to the inter-vehicle time Tin. This structure allows the lateral position of the vehicle VA to change smoothly with the inter-vehicle time Tin.

[0076] <Example 4> In the second scenario, it is assumed that the relative speed of the first adjacent vehicle OV1 relative to the current vehicle VA is relatively high. In this case, when the first adjacent vehicle OV1 passes by the current vehicle VA, the wind pressure generated by the passing of the first adjacent vehicle OV1 may cause the current vehicle VA to sway laterally. Therefore, the driver of the current vehicle VA may feel uneasy. Therefore, in the second scenario, the driving assistance ECU 110 calculates the relative speed Vrs of the first adjacent vehicle OV1 relative to the current vehicle VA. The relative speed Vrs is the difference between the speed V1 of the first adjacent vehicle OV1 and the speed Va of the current vehicle VA (Vrs = V1 - Va). If the relative speed Vrs is above a predetermined speed threshold Vrth, the driving assistance ECU 110 performs first control. Conversely, if the relative speed Vrs is below the predetermined speed threshold Vrth, the driving assistance ECU 110 performs second control.

[0077] (Processing flow) Figure 16 This is a flowchart illustrating the routine executed by the driving assistance ECU 110 in Embodiment 4. The driving assistance ECU 110 executes... Figure 16 Replace with routines Figure 8 The routine. Figure 16 routines and Figure 8 The difference in the routine is the addition of steps 1601-1602. For the example with... Figure 8 The same steps are followed, the same symbols are assigned, and their descriptions are omitted.

[0078] If in Figure 7 If the second starting condition is met in step 706 of the routine, the driving assistance ECU 110 proceeds to step 1601 via step 707. The driving assistance ECU 110 determines whether the relative speed Vrs is above the specified speed threshold Vrth (step 1601). If the relative speed Vrs is above the specified speed threshold Vrth, the driving assistance ECU 110 determines "yes" and proceeds to step 1602. The driving assistance ECU 110 calculates the line Lofs using the correction value dc and sets the line Lofs as the target trajectory TL (step 1602). The correction value dc can be "dc1 (e.g., -0.4m)". As mentioned above, the correction value dc can be calculated based on the distance Dx or the inter-vehicle time Tin. The subsequent processing (steps 718 and 719) is similar to... Figure 8 same.

[0079] On the other hand, if the relative speed Vrs is not above the specified speed threshold Vrth, the driving assistance ECU 110 determines "no" and executes steps 710, 718 and 719.

[0080] (Effect) Based on the above structure, when the relative speed Vrs is relatively high, the driving assistance ECU 110 performs a first control to set the target trajectory TL away from the first adjacent lane Ln1. The distance between the vehicle VA and the first adjacent vehicle OV1 increases. When the first adjacent vehicle OV1 passes by the vehicle VA, the possibility of the vehicle VA swaying laterally due to the wind pressure generated by the passing of the first adjacent vehicle OV1 can be reduced. Therefore, the possibility of the driver of the vehicle VA feeling uneasy can be reduced.

[0081] <Example 5> use Figure 17 The structure of Embodiment 5 is explained. In the first situation, when the vehicle VA overtakes the first adjacent vehicle OV1, there is an adjacent vehicle OV3 in front of the first adjacent vehicle OV1. In this case, after the lateral position of the vehicle VA temporarily returns to the center line Lc, the lateral position of the vehicle VA moves again to the line Lofs. Because the vehicle VA is swaying laterally, the driver of the vehicle VA may feel uneasy. Considering this, when the vehicle VA overtakes the first adjacent vehicle OV1 and there is an adjacent vehicle OV3 in front of the first adjacent vehicle OV1, the driving assistance ECU 110 continues the first control. The lateral position of the vehicle VA is maintained on the line Lofs. Lateral swaying of the vehicle VA can be prevented.

[0082] (Processing flow) The driving assistance ECU 110 in Example 5 executes... Figure 7 and Figure 8 The routine is as described in Example 1. However, the processing in step 715 differs from that in Example 1. In step 715, the driving assistance ECU 110 determines whether the following first termination condition is met. In this example, the first termination condition is met when both condition B1 and condition B2 are met. (Condition B1): Distance Dx ≥ second distance threshold Dxth2 (a specified positive value) (Condition B2): There are no other adjacent vehicles within a specified distance in front of the first adjacent vehicle OV1.

[0083] (Effect) Based on the above structure, if there is another adjacent vehicle OV3 in front of the first adjacent vehicle OV1, the driving assistance ECU 110 continues the first control. This can prevent the vehicle VA from swaying laterally and reduce the possibility of the driver of the vehicle VA feeling uneasy.

[0084] <Example 6> In the first situation, when the speed Va of vehicle VA is much greater than the speed V1 of the first adjacent vehicle OV1, the time required for vehicle VA to overtake the first adjacent vehicle OV1 is short. If vehicle VA is moved laterally for a short period of time via the first control, the driver of vehicle VA may feel uneasy. Considering this, in the first situation, the driving assistance ECU 110 calculates the time Tov required for vehicle VA to overtake the first adjacent vehicle OV1. If the time Tov is below a predetermined time threshold Toth, the driving assistance ECU 110 maintains the current lateral position of vehicle VA.

[0085] (Processing flow) Figure 18 This is a flowchart illustrating the routine executed by the driving assistance ECU 110 in Embodiment 6. The driving assistance ECU 110 executes... Figure 18 Replace with routines Figure 8 The routine. Figure 18 routines and Figure 8 The difference in the routine is the addition of steps 1801 to 1802. Furthermore, for... Figure 8 The same steps are followed, the same symbols are assigned, and their descriptions are omitted.

[0086] If the first initial condition is met (step 712), the driving assistance ECU 110 executes step 713 and proceeds to step 1801. The driving assistance ECU 110 determines whether the time Tov is below the time threshold Toth (step 1801). If the time Tov is below the time threshold Toth, the driving assistance ECU 110 determines "yes" and proceeds to step 1802. The driving assistance ECU 110 corrects the target trajectory TL to maintain the current lateral position of the vehicle VA. The subsequent processing (steps 718 and 719) is the same as... Figure 8 same.

[0087] On the other hand, if the time Tov is not below the time threshold Toth, the driving assistance ECU 110 determines "No" and proceeds to step 714. The subsequent processing (steps 714, 718, and 719) is the same as... Figure 8 same.

[0088] (Effect) According to the above structure, when the execution time Tov of the first control is below the time threshold Toth, the driving assistance ECU 110 corrects the target trajectory TL to maintain the current lateral position of the vehicle VA. Therefore, the lateral movement of the vehicle VA is suppressed, reducing the likelihood of the driver of the vehicle VA feeling uneasy.

[0089] <Example 7> use Figure 19 The structure of Embodiment 7 is explained. Sometimes the accuracy of the vehicle's peripheral sensors 140 is low. To accurately determine whether the current situation is the first situation, the driving assistance ECU 110 uses a reliability DR defined below. Reliability DR is an indicator of the accuracy of the proximity between the current vehicle VA and the first adjacent vehicle OV1. The driving assistance ECU 110 uses distance Dy to calculate the reliability DR. For example... Figure 19 As shown, distance Dy is the distance between the first adjacent vehicle OV1 and the left dividing line LL, which represents the boundary between lane Ln0 and the first adjacent lane Ln1. Distance Dy is calculated as a positive value.

[0090] The driving assistance ECU 110 operates at a specified cycle dT (e.g., 50ms) according to... Figure 20 The table performs addition, subtraction, or maintenance on the reliability DR. In this example, the upper limit of reliability DR is "20", and the lower limit of reliability DR is "0". Furthermore, in... Figure 20 In this context, Dy1 < Dy2 < Dy3. When the first adjacent vehicle OV1 is detected, the driving assistance ECU110 begins calculating the reliability DR. The reliability DR is initially set to "0".

[0091] When Dy < Dy1, the driving assistance ECU 110 increments the reliability DR by "2.0". When Dy1 ≤ Dy ≤ Dy2, the driving assistance ECU 110 increments the reliability DR by "1.0". When Dy2 ≤ Dy ≤ Dy3, the driving assistance ECU 110 maintains the current reliability DR. When Dy3 < Dy, the driving assistance ECU 110 decrements the reliability DR by "1.0".

[0092] The driving assistance ECU 110 uses the reliability DR to determine the start of the first control. In this example, the first start condition is met when (i) the first adjacent vehicle OV1 is in front of the vehicle VA, (ii) the speed Va of the vehicle VA is greater than the speed V1 of the first adjacent vehicle OV1, and (iii) the reliability DR reaches "20". Similarly, the driving assistance ECU 110 uses the reliability DR to determine the start of the second control. In this example, the second start condition is met when (i) the first adjacent vehicle OV1 is behind the vehicle VA, (ii) the speed V1 of the first adjacent vehicle OV1 is greater than the speed Va of the vehicle VA, and (iii) the reliability DR reaches "20".

[0093] The driving assistance ECU 110 can also use the reliability DR to determine the end of the first control. In this example, after initiating the first control, the driving assistance ECU 110 gradually decreases the reliability DR. The first termination condition is met when the reliability DR reaches a predetermined value (e.g., any value between 0 and 10). Similarly, the driving assistance ECU 110 can also use the reliability DR to determine the end of the second control. In this example, after initiating the second control, the driving assistance ECU 110 gradually decreases the reliability DR. The second termination condition is met when the reliability DR reaches a predetermined value (e.g., any value between 0 and 10).

[0094] (Effect) Based on the above structure, the driving assistance ECU 110 determines whether the current situation is the first or the second situation based on the change in distance Dy. Even when the accuracy of the vehicle peripheral sensors 140 is low, it is not easily affected by noise, etc., and can eliminate the fluctuation of the determination result. This improves the accuracy of determining whether the current situation is the first or the second situation.

[0095] (Modified Example) The reliability DR is not limited to the above examples. It can also be calculated using the relative speed of the first adjacent vehicle OV1 with respect to the current vehicle VA, and / or the distance Dx between the current vehicle VA and the first adjacent vehicle OV1 in the front-rear direction.

[0096] The driving assistance ECU110 can also operate at a specified period dT (e.g., 50ms) according to... Figure 21 The table performs addition, subtraction, or maintenance on the reliability DR. Figure 21 The table is used to determine the first situation, when the distance Dx is negative. Figure 21In the table, Dx1 and Dx2 are both negative, with Dx1 > Dx2. According to this table, the closer the vehicle VA is to the first adjacent vehicle OV1 from behind, the greater the reliability DR. On the other hand, assuming the vehicle VA decelerates while behind the first adjacent vehicle OV1, the vehicle VA gradually moves away from the first adjacent vehicle OV1. In this case, the reliability DR decreases. In this example, the upper limit of reliability DR is "20", and the lower limit of reliability DR is "0". The driving assistance ECU 110 uses the reliability DR to determine the start of the first control. The first start condition is met when the reliability DR reaches "20". Furthermore, the driving assistance ECU 110 uses the reliability DR to determine the end of the first control. After starting the first control, the driving assistance ECU 110 gradually decreases the reliability DR. The first end condition is met when the reliability DR reaches a predetermined value (e.g., any value between 0 and 10). According to this structure, the driving assistance ECU 110 is configured to determine the first situation based on the change in distance Dx. Even when the accuracy of the vehicle's peripheral sensors 140 is low, the accuracy of determining the first situation can be improved. Furthermore, the driving assistance ECU 110 can also use the same method to determine the second situation.

[0097] <Example 8> use Figure 22 The structure of Embodiment 8 is explained below. To determine the first situation, the driving assistance ECU 110 can also define a first region A1 in front of the vehicle VA and within the first adjacent lane Ln1. The first region A1 is used to determine whether there is a first adjacent vehicle OV1 that the vehicle VA will overtake. The driving assistance ECU 110 can also initiate first control when the first adjacent vehicle OV1 enters the first region A1. The driving assistance ECU 110 can also terminate the first control when the first adjacent vehicle OV1 exits the first region A1.

[0098] The driving assistance ECU 110 can also change the longitudinal length Lx1 of the first region A1 according to the speed Va of the vehicle VA. For example, the greater the speed Va, the larger the length Lx1 can be set.

[0099] Furthermore, the driving assistance ECU110 can also change the length Lx1 of the first region A1 in the forward and backward direction according to the driving curvature of the vehicle VA.

[0100] like Figure 23As shown, in another example, suppose vehicle VA attempts to overtake a first adjacent vehicle OV1, and a second adjacent vehicle OV2 attempts to overtake vehicle VA. In this case, the driving assistance ECU 110 can set a second region A2 within the second adjacent lane Ln2. The second region A2 is used to determine situation d. That is, if the first adjacent vehicle OV1 is present in the first region A1 and the second adjacent vehicle OV2 is present in the second region A2, the driving assistance ECU 110 performs processing for situation d. The driving assistance ECU 110 based on... Figure 13 The mapping diagram MP4 shown yields the correction value dc. The driving assistance ECU 110 calculates the line Lofs, which is offset to the right by "dc4" relative to the center line Lc. The driving assistance ECU 110 sets the line Lofs as the target trajectory TL.

[0101] The second region A2 extends from the front of the vehicle VA to the rear of the vehicle VA. The longitudinal length Lx2 of the second region A2 is smaller than the longitudinal length Lx1 of the first region A1; therefore, the second region A2 is smaller than the first region A1. Furthermore, the front end A2_f of the second region A2 is closer to the vehicle VA than the front end A1_f of the first region A1. Based on this structure, the driving assistance ECU 110 can determine condition d with high accuracy.

[0102] The driving assistance ECU110 can also change the length Lx2 of the second area A2 in the forward and backward direction according to the speed Va of the vehicle VA.

[0103] Furthermore, the driving assistance ECU110 can also change the length Lx2 of the second region A2 in the forward and backward direction according to the driving curvature of the vehicle VA.

[0104] Furthermore, the embodiments described above are merely examples, and the scope of the technical concept of this disclosure is not limited to the structures described above. Other methods that can be considered within the scope of the technical concept of this disclosure are also included within the scope of this disclosure.

[0105] The above embodiments and their variations can also be applied to the first situation where the vehicle VA overtakes the second adjacent vehicle OV2 traveling in the second adjacent lane Ln2, and the second situation where the vehicle VA is overtaken by the second adjacent vehicle OV2.

[0106] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described above, and various design changes can be made without departing from the spirit of the present invention as described in the technical solutions. For example, the embodiments described above are embodiments explained in detail for the purpose of easy understanding of the present invention, and are not necessarily limited to having all the structures described. In addition, a part of the structure of some embodiments can be replaced with the structure of other embodiments, and the structure of other embodiments can be added to the structure of some embodiments. Moreover, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced. Symbol Explanation

[0107] 110… Driving assistance ECU, 120… Steering ECU, 130… Steering actuator, 140… Vehicle peripheral sensors, 150… Vehicle speed sensor.

Claims

1. A driving assistance device, characterized in that, have: At least one sensor acquires vehicle perimeter information related to the area surrounding the vehicle; and At least one processor is configured to perform a determination process based on the vehicle's surrounding information to determine whether the current situation is a first situation or a second situation, and based on the result of the determination process, to perform steering control to make the vehicle travel along a target trajectory. The first situation is when the vehicle overtakes another vehicle traveling in a first adjacent lane that is adjacent to the lane in which the vehicle is traveling. The second situation is when the vehicle is overtaken by the first other vehicle. The processor is configured to perform a first control, in the first condition, to set the target trajectory away from the first adjacent lane. The processor is configured to, in the first control, set a line offset by a correction value relative to the center line as the target trajectory, where the center line is a line connecting the center positions of the lanes in the road width direction. The processor is configured to determine whether there is a second other vehicle in a second adjacent lane that is adjacent to the current lane and exists on the opposite side of the first adjacent lane, and if there is a second other vehicle, to change the correction value.

2. The driving assistance device according to claim 1, characterized in that, The processor is configured to continue the first control if a third other vehicle is present in front of the first other vehicle in the first adjacent lane.

3. The driving assistance device according to claim 1, characterized in that, The processor is configured to change the correction value based on the vehicle-to-vehicle distance between the vehicle and the first other vehicle, or the inter-vehicle time between the vehicle and the first other vehicle.

4. The driving assistance device according to claim 1, characterized in that, The processor is configured to determine the first situation using a first area located in front of the vehicle and within the first adjacent lane. The presence of the second other vehicle is determined using a second area set within the second adjacent lane.

5. The driving assistance device according to claim 1, characterized in that, The control gain of the steering control is set to be greater when the second other vehicle is present than when the second other vehicle is not present.

6. The driving assistance device according to claim 1, characterized in that, The processor is configured to correct the target trajectory to maintain the current lateral position of the vehicle if the time required for the vehicle to overtake the first other vehicle during the execution of the first control is below a predetermined time threshold.

7. The driving assistance device according to claim 1, characterized in that, The processor is configured to perform a second control that sets the target trajectory as the center line in the second state.

8. The driving assistance device according to claim 1, characterized in that, The processor is configured to perform a first control that sets the target trajectory away from the first adjacent lane when the relative speed between the vehicle and the first other vehicle is above a predetermined speed threshold in the second situation.

9. The driving assistance device according to claim 1, characterized in that, The processor is configured to determine the first situation or the second situation based on the change in the distance in the road width direction or the distance in the front-rear direction between the vehicle and the first other vehicle.

10. The driving assistance device according to claim 1, characterized in that, The processor is configured to determine the first situation using a first area located in front of the vehicle and within the first adjacent lane.

11. The driving assistance device according to claim 10, characterized in that, The processor is configured to change the length of the first region in the forward and backward direction of the vehicle based on the vehicle's speed or curvature.

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