Vehicle control device and vehicle control method

Abstract

To suppress a non-smooth behavior of a vehicle in simultaneous operation of first steering control and second steering control, and satisfy a requirement to achieve both of the steering controls.SOLUTION: A processor of a vehicle control device executes first steering control and second steering control. In the first steering control, a processor calculates a first target horizontal position to prevent deviation of a vehicle from a traveling traffic lane, and a second target horizontal position positioned closer to a front vehicle side and a central side of the traveling traffic line than the first target horizontal position. In the second steering control, the processor calculates a third target horizontal position so as to secure a horizontal distance to reduce collision risk between a target and the vehicle. The processor controls a steering actuator so as to satisfy the first target horizontal position in simultaneous operation of the first steering control and the second steering control, then satisfy an offset-amount in a traffic lane width direction to the target having a larger absolute value between the second target horizontal position and the third target horizontal position.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device and a vehicle control method.

Background Art

[0002] Patent Document 1 discloses a driving support system applied to a vehicle. The control device of this driving support system executes driving support control (PDA: Proactive Driving Assist) including steering control for reducing the collision risk with a target in front of the vehicle based on surrounding situation information and vehicle state information.

[0003] Also, as a driving support control different from PDA, lane departure suppression control (LDA: Lane Departure Alert with a steering function) is known. In LDA, the steering actuator is controlled to suppress the departure of the vehicle from the traveling lane.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] According to the LDA (First Steering Control) and PDA (Second Steering Control) described above, target lateral positions are calculated individually according to the purpose of each control. When LDA and PDA are operating simultaneously, in order to mediate the target lateral positions, it is conceivable to sequentially select the required steering angle with the larger absolute value between the required steering angle according to the target lateral position of LDA and the required steering angle according to the target lateral position of PDA. However, if such a mediation method is adopted, the required steering angles of both will be realized alternately, resulting in jerky vehicle behavior. Furthermore, if the operation of either LDA or PDA is always prioritized, it becomes impossible to meet the requirements that each LDA and PDA is intended to achieve.

[0006] This disclosure has been made in view of the above-mentioned issues, and its purpose is to suppress jerky vehicle behavior when the first steering control for lane departure prevention and the second steering control for collision risk reduction are operated simultaneously, and to enable the requirements to be achieved by both steering controls to be met. [Means for solving the problem]

[0007] The vehicle control device according to this disclosure comprises a steering actuator, a recognition sensor for recognizing the surrounding conditions of the vehicle, and a processor. The processor performs a first steering control to suppress the vehicle from deviating from the driving lane and a second steering control to reduce the risk of collision with an object in front of the vehicle. In the first steering control, the processor calculates a first target lateral position to prevent the vehicle from deviating from the driving lane and a second target lateral position located further forward than the first target lateral position and closer to the center of the driving lane. In the second steering control, the processor calculates a third target lateral position to secure a lateral distance between the vehicle and the object to reduce the risk of collision. When the first and second steering control are operating simultaneously, the processor controls the steering actuator to satisfy the first target lateral position, and then to satisfy the larger of the absolute values ​​of the offset amount in the lane width direction relative to the object between the second and third target lateral positions.

[0008] The processor's control of the steering actuator during simultaneous operation may include feedback control of the steering actuator so that the vehicle's lateral position approaches the first target lateral position, and feedback control of the steering actuator after the lateral position has reached the first target lateral position so that the lateral position approaches the second target lateral position or the third target lateral position, whichever has the larger absolute value of the offset amount.

[0009] When the steering actuator is being feedback-controlled so that the lateral position approaches the first target lateral position, the upper limit of the time rate of change of the required steering angle of the vehicle may be greater than the upper limit of the time rate of change of the required steering angle when the steering actuator is being feedback-controlled so that the lateral position approaches the third target lateral position, in the case where the third target lateral position corresponds to the larger of the absolute values ​​of the offset amount.

[0010] The vehicle control method according to this disclosure is applied to a vehicle equipped with a steering actuator and a recognition sensor that recognizes the surrounding conditions of the vehicle, and performs a first steering control to suppress the vehicle from deviating from the driving lane and a second steering control to reduce the risk of collision with an object in front of the vehicle. The vehicle control method includes, in the first steering control, calculating a first target lateral position to prevent the vehicle from deviating from the driving lane and a second target lateral position located forward of the vehicle and towards the center of the driving lane; in the second steering control, calculating a third target lateral position to secure a lateral distance between the vehicle and the object to reduce the risk of collision; and, when the first steering control and the second steering control are operating simultaneously, controlling the steering actuator to satisfy the first target lateral position, and then to satisfy the larger of the absolute values ​​of the offset amount in the lane width direction relative to the object between the second target lateral position and the third target lateral position. [Effects of the Invention]

[0011] According to this disclosure, when the first steering control and the second steering control are operated simultaneously, first, the first target lateral position, which prevents the vehicle from deviating from the driving lane, is satisfied. This satisfies the requirement of the first steering control, "lane departure suppression." Subsequently, the larger of the absolute values ​​of the offset amount in the lane width direction relative to the target between the second target lateral position and the third target lateral position is satisfied. This ensures an offset amount equal to or greater than the offset amount of the third lateral position. In other words, the requirement of the second steering control, "collision risk reduction," is also satisfied. With this type of steering actuator control, it is possible to suppress the jerky behavior of the vehicle caused by the integration of target lateral positions, and to satisfy the requirements to be achieved by both steering controls. [Brief explanation of the drawing]

[0012] [Figure 1] This diagram illustrates an example of the configuration of a vehicle equipped with a vehicle control device according to the embodiment, along with an overview of the first steering control (LDA) and the second steering control (PDA). [Figure 2] This diagram illustrates the challenges of simultaneous operation of an LDA and a PDA. [Figure 3] This diagram illustrates the steering control performed in the embodiment when the LDA and PDA are operating simultaneously. [Figure 4] This diagram illustrates steering control according to the integrated target lateral position Y*. [Figure 5] This flowchart shows an example of the processing flow related to steering control according to the embodiment. [Figure 6] This figure shows an image of the time evolution of the required rudder angle with respect to the integrated target lateral position Y*. [Modes for carrying out the invention]

[0013] Hereinafter, a vehicle control device and a vehicle control method according to embodiments of this disclosure will be described with reference to the attached drawings. In each drawing, elements common to all are denoted by the same reference numerals, and redundant explanations are omitted or simplified.

[0014] 1. Example of vehicle configuration Figure 1 is a diagram illustrating an example of the configuration of a vehicle equipped with a vehicle control device according to an embodiment, along with an overview of the first steering control and the second steering control. The vehicle 10 shown in Figure 1 is equipped with an electronic control unit (ECU) 20, a sensor group 30, and a steering actuator 40.

[0015] The ECU 20 is a computer that controls the vehicle 10. The ECU 20 includes one or more processors (hereinafter simply referred to as "processors") 22 and one or more storage devices (hereinafter simply referred to as "storage devices") 24. The processor 22 performs various processes related to steering control of the vehicle 10. The storage devices 24 store various information necessary for processing by the processor 22. Various processes by the processor 22 are realized by the processor 22 executing various computer programs. Various computer programs are stored in the storage devices 24 or recorded on a computer-readable recording medium. Note that the ECU 20 may be composed of multiple ECUs.

[0016] The sensor group 30 includes a recognition sensor 32 that recognizes the surrounding conditions of the vehicle 10. The recognition sensor 32 is electrically connected to the ECU 20. The recognition sensor 32 includes, for example, at least one of a camera, millimeter-wave radar, and LiDAR (Laser Imaging Detection and Ranging). The recognition sensor 32 can, for example, detect lane markings (e.g., outer edge lines 2 of the roadway) or detect objects OB in front of the vehicle 10. The sensor group 30 also includes, for example, a steering angle sensor that detects the steering angle of the vehicle 10.

[0017] The steering actuator 40 generates a force to steer the wheels of the vehicle 10. The steering actuator 40 can assist the driver in steering, and can also steer the wheels independently of the driver's steering.

[0018] In the example of the vehicle 10 having the above-described configuration, the "vehicle control device" according to the present disclosure includes an ECU 20 including a processor 22, a recognition sensor 32, and a steering actuator 40. More specifically, the "vehicle control device" according to the present disclosure corresponds to, for example, a driving support device that supports the driving of the vehicle 10 by a driver. Further, the "vehicle control device" may be a device that performs automatic driving of the vehicle 10. That is, the vehicle 10 may be an autonomous vehicle.

[0019] 2. Steering control The steering control of the vehicle 10 executed by the ECU 20 (processor 22) includes the "first steering control for suppressing lane departure" and the "second steering control for reducing the collision risk with the target OB" described below with reference to FIG. 1.

[0020] 2-1. First steering control (LDA) The first steering control (hereinafter also referred to as "LDA") controls the steering actuator 40 so as to suppress the departure of the vehicle 10 from the travel lane 1. FIG. 1 illustrates a vehicle 10 that is about to deviate from the outside lane line 2 (for example, a white line) which is one of a pair of lane dividing lines that define the travel lane 1.

[0021] The operating condition of LDA is established when it is estimated that the vehicle 10 deviates from the travel lane 1. The operating condition of LDA includes, for example, that the lateral distance (lateral distance) Dy_LDA in the lane width direction between the lane dividing line (for example, the outside lane line 2) and the vehicle 10 is less than a predetermined threshold value. More specifically, the lateral distance Dy_LDA is the distance between the lane dividing line and the vehicle reference line Lv. In FIG. 1, the vehicle reference line Lv, which is a straight line or a curve extending along the extending direction of the travel lane 1, passes through the center Pv of the vehicle 10 as an example.

[0022] When the LDA activation conditions are met, the ECU 20 warns the driver that the vehicle 10 may deviate from the driving lane 1 and calculates the target lateral position Y*_LDA1 (first target lateral position) and target lateral position Y*_LDA2 (second target lateral position). "Lateral position Y" is the position of the vehicle 10 along the lane width direction perpendicular to the extension direction of the driving lane 1 (for example, the position of the center Pv of the vehicle 10). The reference position for "Lateral position Y" is, for example, the center Lc of the driving lane 1.

[0023] The target lateral position Y*_LDA1 is the target lateral position Y* that prevents vehicle 10 from deviating from lane 1. More specifically, the target lateral position Y*_LDA1 is predetermined, for example, by considering the width of vehicle 10 (a known value), such that the edges of vehicle 10 in the width direction do not exceed the lane markings.

[0024] On the other hand, as illustrated in Figure 1, the target lateral position Y*_LDA2 is determined to be located further forward of the vehicle and towards the center of lane 1 than the target lateral position Y*_LDA1. For example, the target lateral position Y*_LDA2 is calculated by adding a predetermined offset amount to the target lateral position Y*_LDA1.

[0025] Furthermore, during LDA, the ECU 20 controls the steering actuator 40 so that the vehicle 10 passes through target lateral positions Y*_LDA1 and Y*_LDA2 in sequence (see, for example, path P1 in Figure 2(B) described later). LDA ends when the lateral position Y of the vehicle 10 reaches the target lateral position Y*_LDA2.

[0026] Specifically, the ECU 20 provides feedback control to the steering actuator 40 so that the (actual) lateral position Y of the vehicle 10 approaches the target lateral positions Y*_LDA1 and Y*_LDA2 in sequence. In this feedback control, a required steering angle θ is set to reduce the deviation ΔY between the lateral position Y and the target lateral position Y*. The required steering angle θ is set to increase as the deviation ΔY increases. That is, as long as a large deviation ΔY exists, the steering actuator 40 is continuously required to steer at a large required steering angle θ. Then, as the deviation ΔY decreases, the required steering angle θ decreases (i.e., the steering angle is returned to its original position). However, there is an upper limit on the rate of change of the required steering angle θ over time (required steering angular velocity).

[0027] According to the LDA described above, the steering actuator 40 is first controlled so that the target lateral position Y*_LDA1 is satisfied. This allows for quick avoidance of lane departure while preventing the amount of change in lateral position Y per unit time from becoming too large, compared to the case where only, for example, target lateral position Y*_LDA2 is used as the target lateral position Y* in the LDA. Then, by controlling the steering actuator 40 so that the target lateral position Y*_LDA2 is satisfied, the vehicle 10 can be moved away from the lane markings (for example, the outer edge line of the roadway 2) that were too close.

[0028] 2-2. Second Steering Control (PDA) The second steering control (hereinafter also referred to as "PDA") controls the steering actuator 40 to reduce the risk of collision with an object OB in front of the vehicle 1 (for example, on the shoulder of the road). The object OB here includes, for example, pedestrians (see Figure 1) and bicycles.

[0029] The PDA (Pedestrian Distance Acceleration) is activated when it is estimated that there is a high risk of collision between the vehicle 10 and a target OB (Obstructed Line), such as a pedestrian. The PDA's activation conditions include, for example, that the lateral distance Dy_PDA between the target OB and the vehicle 10 is less than a predetermined threshold. More specifically, the lateral distance Dy_PDA is the distance between the target OB and the vehicle reference line Lv. The PDA's activation conditions may also include, for example, that the collision margin time TTC (Time Tolerance) is less than a threshold. The collision margin time TTC is calculated using the distance (longitudinal distance) between the vehicle 10 and the target OB in the direction of vehicle travel and the relative speed of the vehicle 10 with respect to the target OB.

[0030] When the PDA operating conditions are met, the ECU20 calculates the target lateral position Y*_PDA (third target lateral position). The target lateral position Y*_PDA is the target lateral position Y* required to secure a lateral distance Dy between the vehicle and the target OB within the driving lane 1 to reduce the risk of collision with the target OB. For example, the target lateral position Y*_PDA is calculated by adding a predetermined offset amount to the lateral distance Dy_PDA mentioned above. This offset amount corresponds to the margin of the lateral position Y required to reduce the risk of collision with the target OB.

[0031] Furthermore, in the PDA, the ECU 20 controls the steering actuator 40 so that the vehicle 10 passes through the target lateral position Y*_PDA (see, for example, path P2 in Figure 2(B) described later).

[0032] Specifically, the ECU 20 provides feedback control to the steering actuator 40 so that the (actual) lateral position Y of the vehicle 10 approaches the target lateral position Y_PDA. Similar to LDA, this feedback control also sets a required steering angle θ to reduce the deviation ΔY between the lateral position Y and the target lateral position Y*. The required steering angle θ is set to increase as the deviation ΔY increases. That is, as long as a large deviation ΔY exists, the steering actuator 40 is continuously required to steer at a large required steering angle θ. Then, as the deviation ΔY decreases, the required steering angle θ decreases (i.e., the steering angle is returned to its original position). However, there is an upper limit on the rate of change of the required steering angle θ over time (required steering angular velocity).

[0033] According to the PDA described above, by controlling the steering actuator 40 so that the target lateral position Y*_PDA is satisfied, the lateral position Y of the vehicle 10 can be controlled so that the risk of collision with the target OB is reduced within the vehicle's driving lane 1.

[0034] (Upper limit of the rate of change over time of the required rudder angle θ) The upper limit of the time rate of change of the required steering angle θ in LDA and PDA is set as follows, for example: The upper limit of the time rate of change of the required steering angle θ in LDA (first steering control) is greater than the upper limit of the time rate of change of the required steering angle θ in PDA (second steering control). Thus, in LDA, where it is necessary to quickly avoid an imminent lane departure, a higher time rate of change of the required steering angle θ is permitted compared to PDA, which is performed proactively.

[0035] 2-3. Mediation and Integration Method for Target Horizontal Position Y* The LDA and PDA mentioned above may operate simultaneously. More specifically, simultaneous operation of the LDA and PDA refers to the time when the target lateral position Y* of the LDA and PDA begin to be output simultaneously. Figures 2(A) and 2(B) illustrate the challenges of simultaneous operation of the LDA and PDA. More specifically, this scenario assumes that the target OB is located ahead of the vehicle at the point where vehicle 10 may deviate from its lane.

[0036] 2-3-1. Assignment Figure 2(A) shows the time waveforms of the required steering angle θ during operation of the LDA and PDA, respectively. When the LDA and PDA are operating simultaneously, as shown by the solid lines in Figure 2(A), it is conceivable that the system would sequentially select the required steering angle θ with the larger absolute value between the required steering angle θ_LDA (dashed line) corresponding to the LDA's target lateral positions Y*_LDA1 and Y*_LDA2 and the required steering angle θ_PDA (dotted line) corresponding to the PDA's target lateral position Y*_PDA. However, if such a arbitration method is adopted, as illustrated in Figure 2(A), both required steering angles θ will be realized alternately, resulting in jerky behavior of the vehicle 10.

[0037] Furthermore, if either LDA or PDA operation is always prioritized, it may become impossible to meet the requirements that each LDA and PDA aims to achieve. Specifically, if LDA is prioritized over PDA, the steering actuator 40 will be controlled to satisfy the target lateral positions Y*_LDA1 and Y*_LDA2 for LDA. As a result, as shown in the example path P1 in Figure 2(B), the target lateral position Y*_LDA2 for PDA may not be sufficient compared to the target lateral position Y*_PDA, and the requirements for PDA will not be met. In other words, the risk of collision will not be sufficiently reduced. On the other hand, if PDA is prioritized over LDA, the steering actuator 40 will be controlled to satisfy the target lateral position Y*_PDA for PDA. As a result, if the upper limit of the time rate of change of the required steering angle θ is set smaller than that of LDA, it may become impossible to meet the requirements for LDA, as shown in the example path P2 in Figure 2(B). In other words, it may become impossible to avoid lane departure.

[0038] 2-3-2. Countermeasures Figure 3 is a diagram illustrating the steering control performed in the embodiment when LDA and PDA are operating simultaneously. In view of the above-mentioned problems, in this embodiment, when LDA and PDA are operating simultaneously, the ECU 20 (processor 22) first unconditionally (in other words, with the highest priority) selects the target lateral position Y*_LDA1. Next, the ECU 20 selects the one with the larger absolute value of the offset amount OS in the lane width direction relative to the target OB from among the target lateral position Y*_LDA2 and the target lateral position Y*_PDA.

[0039] In the example shown in Figure 3, the absolute value of the offset amount OS_PDA of the target lateral position Y*_PDA relative to the target OB is greater than the absolute value of the offset amount OS_LDA of the target lateral position Y*_LDA2 relative to the target OB. Therefore, the target lateral position Y*_PDA is selected. Unlike the example shown in Figure 3, if the absolute value of the offset amount OS_LDA is greater than the absolute value of the offset amount OS_PDA, the target lateral position Y*_LDA2 is selected. Thus, in either example, an offset amount OS equal to or greater than the offset amount OS_PDA of the target lateral position Y*_PDA is secured. Note that the offset amount OS is considered positive when the target lateral position Y* is located to the right of the vehicle's direction of travel relative to the target OB, as in the example shown in Figure 3.

[0040] By selecting two target lateral positions Y* from the three target lateral positions Y* in LDA and PDA as described above, the target lateral positions Y* of the two steering control systems, LDA and PDA, are integrated. Figure 4 is a diagram illustrating steering control according to the integrated target lateral positions Y*. Figure 4 corresponds to an example of target lateral position Y* integration shown in Figure 3. In this example, the ECU 20 controls the steering actuator 40 to first satisfy target lateral position Y*_LDA1 and then target lateral position Y*_PDA from the two integrated target lateral positions Y*. As a result of this control, as shown in Figure 4, the vehicle 10's path P3 becomes such that the vehicle 10 passes through target lateral position Y*_LDA1 and target lateral position Y*_PDA in that order.

[0041] 2-3-3. Processing Flow Next, Figure 5 is a flowchart showing an example of the processing flow related to steering control according to the embodiment.

[0042] In step S100, the ECU20 determines whether simultaneous operation of the LDA and PDA has started. This determination result is basically "Yes" when the operating condition of the other LDA or PDA is met while the operating condition of one of the LDA or PDA is already met. If the determination result is "No", the process proceeds to the end.

[0043] On the other hand, if the result of step S100 is Yes, the ECU20 proceeds sequentially to steps S102 to S106 and calculates each target lateral position Y*. That is, each target lateral position Y* is calculated as simultaneous operation begins. Specifically, following the method described above, target lateral position Y*_LDA1 is calculated in step S102, target lateral position Y*_LDA2 is calculated in step S104, and target lateral position Y*_PDA is calculated in step S106.

[0044] Next, in step S108, the ECU 20 selects the target lateral position Y*_LDA1 as the target lateral position Y* and performs feedback control of the steering actuator 40 to bring the lateral position Y of the vehicle 10 closer to the target lateral position Y*_LDA1. The actual (lateral position Y) of the vehicle 10 can be calculated, for example, based on the output of the recognition sensor 32.

[0045] Next, in step S110, the ECU 20 determines whether the lateral position Y of the vehicle 10 has reached the target lateral position Y*_LDA1. As long as the lateral position Y has not reached the target lateral position Y*_LDA1, feedback control continues with the target lateral position Y*_LDA1 as the target lateral position Y*.

[0046] On the other hand, if the lateral position Y reaches the target lateral position Y*_LDA1 in step S108, the process proceeds to step S112. In step S112, the ECU20 determines whether the absolute value of the offset amount OS_LDA of the target lateral position Y*_LDA2 relative to the target OB is greater than the absolute value of the offset amount OS_PDA of the target lateral position Y*_PDA relative to the target OB.

[0047] If, in step S112, the absolute value of the offset amount OS_LDA is greater than the absolute value of the offset amount OS_PDA, the process proceeds to step S114. In step S114, the ECU 20 selects the target lateral position Y*_LDA2 as the target lateral position Y* and provides feedback control to the steering actuator 40 so that the lateral position Y approaches the target lateral position Y*_LDA2.

[0048] On the other hand, if the absolute value of the offset amount OS_LDA in step S112 is less than or equal to the absolute value of the offset amount OS_PDA, the process proceeds to step S116. In step S116, the ECU 20 selects the target lateral position Y*_PDA as the target lateral position Y* and provides feedback control to the steering actuator 40 so that the lateral position Y approaches the target lateral position Y*_PDA.

[0049] In addition, as already explained, the upper limit of the time rate of change of the required steering angle θ in LDA is greater than the upper limit of the time rate of change of the required steering angle θ in PDA. Therefore, the upper limit UL_LDA1 of the time rate of change of the required steering angle θ when the steering actuator 40 is feedback controlled in step S108 so that the lateral position Y approaches the target lateral position Y*_LDA1 is greater than the upper limit UL_PDA of the time rate of change of the required steering angle θ when the steering actuator 40 is feedback controlled in step S108 so that the lateral position Y approaches the target lateral position Y*_PDA.

[0050] 3. Effects As explained above, according to this embodiment, when LDA and PDA are operating simultaneously, steering control is performed with the highest priority given to satisfying the target lateral position Y*_LDA1. This satisfies the LDA requirement of "lane departure suppression". Subsequently, steering control is performed to satisfy the larger of the absolute values ​​of the offset amount OS in the lane width direction relative to the target OB, between the target lateral position Y*_LDA2 and the target lateral position Y*_PDA. This ensures that an offset amount OS equal to or greater than the offset amount OS_PDA of the target lateral position Y*_PDA is secured. Therefore, the PDA requirement of "reduction of collision risk with targets OB such as pedestrians" is also satisfied.

[0051] More specifically, according to this embodiment, steering control is performed with respect to the integrated target lateral position Y*, as illustrated in Figure 4, thereby satisfying the requirements of LDA and PDA. Figure 6 is a diagram illustrating the time evolution of the required steering angle θ with respect to the integrated target lateral position Y*. According to the arbitration and integration method for the target lateral position Y* in this embodiment, the required steering angle θ with respect to the integrated target lateral position Y* is calculated more smoothly compared to the comparative example shown in Figure 2(A), as shown by the solid line in Figure 6. Therefore, jerky behavior of the vehicle 10 can be suppressed.

[0052] Furthermore, in this embodiment, the upper limit UL_LDA1 of the time rate of change of the required steering angle θ when the steering actuator 40 is feedback controlled so that the lateral position Y approaches the target lateral position Y*_LDA1 is greater than the upper limit UL_PDA when the steering actuator 40 is feedback controlled so that the lateral position Y approaches the target lateral position Y*_PDA. As a result, compared to the example where these upper limits UL_LDA1 and UL_PDA are the same, lane departure of the vehicle 10 can be suppressed more reliably when the steering actuator 40 is feedback controlled so that the lateral position Y approaches the target lateral position Y*_LDA1. [Explanation of Symbols]

[0053] 1 Driving lane, 2 Outer lane line, 10 Vehicle, 20 Electronic control unit (ECU), 22 Processor, 24 Memory device, 30 Sensor group, 32 Recognition sensor, 40 Steering actuator

Claims

1. Steering actuator and A recognition sensor that recognizes the surrounding conditions of the vehicle, A processor that performs a first steering control to suppress the vehicle from deviating from its lane, and a second steering control to reduce the risk of collision with an object in front of the vehicle. Equipped with, In the first steering control, the processor calculates a first target lateral position to prevent the vehicle from deviating from the driving lane, and a second target lateral position located forward of the vehicle and towards the center of the driving lane, In the second steering control, the processor calculates a third target lateral position to secure a lateral distance between itself and the target to reduce the risk of collision. The processor, when the first steering control and the second steering control are operating simultaneously, satisfies the first target lateral position, and then controls the steering actuator to satisfy the larger of the absolute values ​​of the offset amount in the lane width direction relative to the target, between the second target lateral position and the third target lateral position. Vehicle control device.

2. The control of the steering actuator by the processor during the aforementioned simultaneous operation is as follows: The steering actuator is controlled by feedback so that the lateral position of the vehicle approaches the first target lateral position. After the lateral position reaches the first target lateral position, the steering actuator is feedback controlled so that the lateral position approaches the second target lateral position and the third target lateral position, whichever has the larger absolute value of the offset amount. including The vehicle control device according to claim 1.

3. When the steering actuator is being feedback-controlled so that the lateral position approaches the first target lateral position, the upper limit of the time rate of change of the vehicle's required steering angle is greater than the upper limit of the time rate of change of the required steering angle when the steering actuator is being feedback-controlled so that the lateral position approaches the third target lateral position when the third target lateral position corresponds to the larger of the absolute values ​​of the offset amount. The vehicle control device according to claim 2.

4. A vehicle control method applicable to a vehicle equipped with a steering actuator and a recognition sensor for recognizing the surrounding conditions of the vehicle, comprising: a first steering control for suppressing the vehicle's departure from the driving lane; and a second steering control for reducing the risk of collision with an object in front of the vehicle, In the first steering control, a first target lateral position is calculated to prevent the vehicle from deviating from the driving lane, and a second target lateral position is calculated to be located forward of the first target lateral position and towards the center of the driving lane. In the second steering control described above, a third target lateral position is calculated to secure a lateral distance between the target and the object in order to reduce the risk of collision, When the first steering control and the second steering control are operated simultaneously, the steering actuator is controlled to satisfy the first target lateral position, and then to satisfy the larger of the absolute values ​​of the offset amount in the lane width direction relative to the target among the second target lateral position and the third target lateral position. including Vehicle control method.

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