Vehicle control device

Abstract

To provide a vehicle control device which executes backup control for lane-keeping assist control in accordance with the running situation of a vehicle and which can prevent the vehicle from being displaced greatly from the center position of a lane even if an abnormality occurs on an electric power steering device.SOLUTION: A vehicle control device includes: an electric power steering device; and a control unit that executes traffic-lane-keeping control which is control for causing a vehicle to run along an aiming running line. The control unit determines whether a predetermined condition that is satisfied when the vehicle is running on a curved section is satisfied or not, when an abnormality occurs on the electric power steering device in execution of the traffic-lane-keeping control. When the predetermined condition is satisfied, the control unit executes certain control that is control for preventing the vehicle from being displaced from the aiming running line.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] Conventionally known vehicle control devices execute lane keeping control, which is a control for driving a vehicle along a target driving line by changing the steering angle (steering angle) of the steering wheels of the vehicle (see, for example, Patent Document 1). For example, the target driving line is a line connecting the center positions of the lanes in which the vehicle is driving. The above lane keeping control may also be referred to as "lane keeping assist control" or "lane tracing assist control." Hereinafter, lane keeping control will be simply referred to as "LKA." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-162127 A Summary of the Invention

[0004] In vehicles equipped with an electric power steering system (hereinafter simply referred to as "EPS"), some kind of abnormality may occur in the EPS while LKA is being performed. In this case, conventional systems terminate LKA. As a result, the vehicle may deviate significantly from the center position of the lane.

[0005] The present invention has been made to solve the above problems. That is, one of the objects of the present invention is to provide a vehicle control device that can execute backup control of LKA (specific control, which will be described later) according to the driving conditions of the vehicle even if an abnormality occurs in the EPS, thereby preventing the vehicle from deviating significantly from the center position of the lane.

[0006] In one or more embodiments, the vehicle control device includes: an electric power steering device including a steering mechanism (50) and a motor (51), and configured to assist an operation of a steering wheel (SW) by a driver of a vehicle by driving the motor; a control unit (10) that executes lane keeping control, which is a control for driving the motor to change a steering angle of the vehicle so as to make the vehicle travel along a target driving line (TL); Equipped with. The control unit When an abnormality occurs in the electric power steering device while the lane keeping control is being executed, determining whether a predetermined condition that is satisfied when the vehicle is traveling through a curve section is satisfied; When the predetermined condition is satisfied, a specific control is executed to drive the motor so as to prevent the vehicle from deviating from the target driving line. It is structured as follows.

[0007] The vehicle control device having the above configuration executes specific control when the vehicle is traveling on a curved section, thereby making it possible to prevent the vehicle from deviating significantly from a target driving line.

[0008] In the above description, in order to facilitate understanding of the present invention, the names and / or symbols used in the embodiments described below are enclosed in parentheses with respect to the configuration of the invention corresponding to the embodiments. However, each component of the present invention is not limited to the embodiments defined by the names and / or symbols. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a vehicle control device according to an embodiment; [Diagram 2] FIG. 2 is a plan view for explaining lane keeping control (LKA) using a target driving line that is set based on the center line of the lane in which the vehicle is traveling. [Diagram 3] FIG. 2 is a plan view showing a state in which a vehicle is traveling through a curved section. [Figure 4] 4 is a flowchart showing a "steering assist control execution routine" executed by the electric power steering ECU. [Diagram 5] 4 is a flowchart showing an "LKA execution routine" executed by the driving assistance ECU. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] First Embodiment A vehicle control device according to a first embodiment (hereinafter, may be referred to as a "first device") is applied to a vehicle VA.

[0011] As shown in FIG. 1, the vehicle control device includes a driving assistance ECU 10, an engine ECU 20, a brake ECU 30, and an electric power steering ECU (hereinafter referred to as "EPS ECU") 40. These ECUs are electric control units including a microcomputer as a main part, and are connected to each other via a controller area network (CAN) so that they can transmit and receive information. In this specification, the microcomputer includes a CPU, a RAM, a ROM, a non-volatile memory, and an interface (I / F), etc. The CPU realizes various functions by executing instructions (programs, routines) stored in the ROM. For example, the driving assistance ECU 10 includes a microcomputer including a CPU 10a, a RAM 10b, a ROM 10c, a non-volatile memory 10d, and an interface (I / F) 10e, etc.

[0012] The driving assistance ECU 10 is connected to the sensors (including switches) listed below, and receives detection signals or output signals of these sensors.

[0013] The steering angle sensor 11 detects the steering angle θ of the steering wheel SW and outputs a signal representing the steering angle θ. The value of the steering angle θ is zero when the steering wheel SW is in a predetermined reference position (neutral position). The reference position is the position of the steering wheel SW when the vehicle VA travels straight ahead. The value of the steering angle θ is a positive value when the vehicle VA turns left, and a negative value when the vehicle VA turns right. That is, the value of the steering angle θ is a positive value when the steering wheel SW is rotated left from the reference position, and a negative value when the steering wheel SW is rotated right from the reference position.

[0014] The steering torque sensor 12 detects a steering torque Tr acting on the steering shaft US due to an operation (steering operation) of the steering wheel SW by the driver, and outputs a signal indicative of the steering torque Tr. The vehicle speed sensor 13 detects the traveling speed (vehicle speed) SPD of the vehicle VA, and outputs a signal indicative of the vehicle speed SPD. The yaw rate sensor 14 detects the yaw rate Yr of the vehicle VA, and outputs a signal indicative of the yaw rate Yr.

[0015] The steering torque Tr and the yaw rate Yr have positive values ​​when the vehicle VA turns left, and have negative values ​​when the vehicle VA turns right.

[0016] The surrounding sensor 15 is adapted to obtain information about the roads around the vehicle VA (including the driving lanes on which the vehicle is traveling) and about three-dimensional objects existing on the roads. The three-dimensional objects include, for example, moving objects such as pedestrians, four-wheeled vehicles and two-wheeled vehicles, and fixed objects such as guardrails and fences. Hereinafter, these three-dimensional objects are simply referred to as "targets." The surrounding sensor 15 includes a radar sensor 15a and a camera sensor 15b.

[0017] The radar sensor 15a emits, for example, millimeter wave band radio waves (hereinafter referred to as "millimeter waves") to a surrounding area including at least a forward area of ​​the vehicle VA, and receives millimeter waves (i.e., reflected waves) reflected by targets present within the emission range. The radar sensor 15a then determines whether or not there is a target, and calculates information indicating the relative relationship between the vehicle and the target. The information indicating the relative relationship between the vehicle and the target includes the distance between the vehicle and the target, the orientation (or position) of the target relative to the vehicle, and the relative speed of the target relative to the vehicle. The information obtained from the radar sensor 15a (including the information indicating the relative relationship between the vehicle and the target) is referred to as "target information."

[0018] The camera sensor 15b photographs the scenery ahead of the vehicle VA to obtain image data. Based on the image data, the camera sensor 15b recognizes the left and right dividing lines (e.g., the left and right white lines) that define the driving lane, and calculates parameters that indicate the shape of the driving lane (e.g., curvature) and parameters that indicate the positional relationship between the vehicle and the driving lane. The parameter that indicates the positional relationship between the vehicle and the driving lane is, for example, the distance from the left or right white line to the center position of the vehicle in the vehicle width direction. The information obtained by the camera sensor 15b is referred to as "lane information." The camera sensor 15b may be configured to determine the presence or absence of a target based on the image data and calculate the target information.

[0019] The surrounding sensor 15 outputs information on the surrounding conditions of the vehicle, including "target information and lane information", to the driving assistance ECU 10 as "vehicle surrounding information".

[0020] The operation switch 16 is a switch operated by the driver. By operating the operation switch 16, the driver can set the operation state of an adaptive cruise control, which will be described later, to an on state or an off state. The adaptive cruise control is sometimes referred to as "adaptive cruise control." Hereinafter, the adaptive cruise control will be simply referred to as "ACC." Furthermore, the driver can set the operation state of the LKA to an on state or an off state by operating the operation switch 16.

[0021] The engine ECU 20 is connected to the engine actuator 21. The engine actuator 21 includes a throttle valve actuator that changes the opening degree of a throttle valve of the internal combustion engine 22. The engine ECU 20 can change the torque generated by the internal combustion engine 22 by driving the engine actuator 21. The torque generated by the internal combustion engine 22 is transmitted to driving wheels via a transmission (not shown). Therefore, the engine ECU 20 can control the driving force of the vehicle and change the acceleration state (acceleration) by controlling the engine actuator 21. Note that the vehicle may be provided with an electric motor as a vehicle driving source instead of or in addition to the internal combustion engine 22.

[0022] The brake ECU 30 is connected to a brake actuator 31, which is a hydraulic control actuator. The brake actuator 31 includes a hydraulic circuit. The hydraulic circuit includes a master cylinder, a flow path through which braking fluid flows, a plurality of valves, a pump, and a motor for driving the pump. The brake actuator 31 adjusts the hydraulic pressure supplied to a wheel cylinder built into the brake mechanism 32 in response to an instruction from the brake ECU 30. The wheel cylinder generates a frictional braking force on the wheels due to the hydraulic pressure. Therefore, the brake ECU 30 can control the braking force of the vehicle and change the acceleration state (deceleration, i.e., negative acceleration) by controlling the brake actuator 31.

[0023] The EPS·ECU 40 is a device that controls a well-known electric power steering device. The electric power steering device includes at least a steering mechanism 50 and a motor 51. The steering mechanism 50 is a mechanism for steering the steered wheels (front left wheel FWL and front right wheel FWR) by rotating the steering wheel SW. The steering mechanism 50 includes the steering wheel SW, a steering shaft US connected to the steering wheel SW, and a steering gear mechanism. The motor 51 is configured to apply a torque to the steering mechanism 50 for steering the steered wheels of the vehicle VA. For example, the EPS·ECU 40 is configured to assist the driver's operation of the steering wheel SW by driving the motor 51. Such control is well-known and will be referred to as "steering assist control" hereinafter.

[0024] (Steering assist control) An overview of the steering assist control will be described below. The EPS·ECU 40 applies the steering torque Tr and the vehicle speed SPD to a predetermined map to obtain the assist torque Atr. When the assist torque Atr is a positive value, the motor 51 applies to the steering mechanism 50 a torque that assists in the operation of the steering wheel SW in the left direction. When the assist torque Atr is a negative value, the motor 51 applies to the steering mechanism 50 a torque that assists in the operation of the steering wheel SW in the right direction. This type of control will be referred to hereinafter as "normal assist control."

[0025] An abnormality may occur in the EPS. Hereinafter, such an abnormality will be referred to as "EPS abnormality." When an EPS abnormality occurs, the EPS·ECU 40 executes backup control. This type of control will be referred to as "backup assist control." The EPS·ECU 40 calculates the assist torque Atr in the same manner as described above. When the magnitude (absolute value) of the assist torque Atr exceeds a predetermined upper limit value, the EPS·ECU 40 limits the magnitude of the assist torque Atr by this upper limit value. Therefore, in the backup assist control, the degree of assist in response to the operation of the steering wheel SW may be smaller than in the normal assist control.

[0026] (ACC) The driving assistance ECU 10 is configured to execute ACC as one mode of driving assistance control. The ACC itself is well known (see, for example, Japanese Patent Application Laid-Open No. 2014-148293, Japanese Patent Application Laid-Open No. 2006-315491, and Japanese Patent No. 4172434, etc.).

[0027] ACC includes two types of control: constant speed cruise control and preceding vehicle following control. Constant speed cruise control is a control that adjusts the acceleration of the vehicle VA so that the traveling speed of the vehicle VA matches a target speed (set speed) Vset without the need to operate the accelerator pedal or brake pedal. Preceding vehicle following control is a control that makes the vehicle VA follow the preceding vehicle (the vehicle to be followed) while maintaining the inter-vehicle distance Dset between the vehicle VA and the preceding vehicle (the vehicle to be followed) at the target inter-vehicle distance Dset without the need to operate the accelerator pedal or brake pedal. The vehicle to be followed is a vehicle that is traveling in the area ahead of the vehicle VA and immediately before the vehicle VA.

[0028] When the operation state of the ACC is set to the on state by operating the operation switch 16, the driving assistance ECU 10 executes constant speed cruise control when there is no vehicle to be followed, and executes preceding vehicle following control when there is a vehicle to be followed.

[0029] (LKA) The driving assistance ECU 10 is configured to execute the LKA as one mode of driving assistance control. When the ACC is in the ON state, the driving assistance ECU 10 is configured to set the LKA to the ON state in response to the operation of the operation switch 16.

[0030] LKA is a control that applies an automatic steering torque Btr to the steering mechanism 50 to change the steering angle of the steering wheels of the vehicle VA so that the vehicle VA travels along a target driving line TL that is set by utilizing a plurality of lane markings or a driving path of a preceding vehicle (i.e., a preceding vehicle path), or both. LKA itself is well known (see, for example, Japanese Patent Application Laid-Open No. 2008-195402, Japanese Patent Application Laid-Open No. 2009-190464, Japanese Patent Application Laid-Open No. 2010-6279, and Japanese Patent No. 4349210, etc.). Note that the automatic steering torque Btr is different from the above-mentioned assist torque Atr, and is a torque that is applied to the steering mechanism 50 by the drive of the motor 51 regardless of the operation of the steering wheel SW by the driver.

[0031] As shown in Fig. 2, it is assumed that the driving assistance ECU 10 can acquire information about the "left and right demarcation lines LL and RL" of the lane (driving lane) in which the vehicle VA is traveling based on the lane information included in the vehicle surroundings information. In this case, the driving assistance ECU 10 estimates the line connecting the center positions of the left and right demarcation lines LL and RL in the road width direction as the "lane center line LM." The driving assistance ECU 10 sets the center line LM as the target driving line TL.

[0032] The driving assistance ECU 10 may set the target driving line TL based on the trajectory of the preceding vehicle or a combination of the trajectory of the preceding vehicle and the center line LM.

[0033] The driving assistance ECU 10 calculates LKA control parameters required to execute LKA based on the lane information. The LKA control parameters include the curvature CL (= the reciprocal of the curvature radius R of the center line LM) of the target driving line TL, the distance dL, and the yaw angle θL, as shown in FIG. 2. The distance dL is the distance in the y-axis direction (effectively in the road width direction) between the target driving line TL and the center position of the vehicle VA in the vehicle width direction. The yaw angle θL is the angle of the longitudinal axis of the vehicle VA with respect to the target driving line TL. In FIG. 3, the x-axis is an axis extending in the longitudinal direction of the vehicle VA, and the y-axis is an axis perpendicular to the x-axis.

[0034] The driving assistance ECU 10 uses the LKA control parameters (CL, dL, θL) to calculate an automatic steering torque Btr for driving the vehicle VA along the target driving line TL, for example, according to the following formula A. (Formula A) Btr=K1·(SPD 2 CL) + K2 dL + K3 θL K1, K2, and K3 are control gains.

[0035] When the automatic steering torque Btr has a positive value, the motor 51 applies a torque to the steering mechanism 50 that steers the steered wheels to the left. When the automatic steering torque Btr has a negative value, the motor 51 applies a torque to the steering mechanism 50 that steers the steered wheels to the right.

[0036] The driving assistance ECU 10 may obtain the automatic steering torque Btr by applying the LKA control parameters (CL, dL, θL) to a predetermined automatic steering torque map MBtr (CL, dL, θL).

[0037] The driving assistance ECU 10 controls the motor 51 using the steering ECU 40 so that the actual torque generated by the motor 51 coincides with the automatic steering torque Btr.

[0038] (Overview of operation) An EPS abnormality may occur during LKA execution. In such a situation, the conventional system terminates LKA, which may cause the vehicle to deviate from the center position of the lane.

[0039] In response to this, the driving assistance ECU 10 in this embodiment executes backup control of the LKA. Hereinafter, such control is referred to as "specific control." The specific control is a control for suppressing deviation of the vehicle VA from the target driving line TL (center position of the lane). The specific control is preferably executed in a situation where the possibility of deviation of the vehicle VA from the target driving line TL increases. Taking this into consideration, the driving assistance ECU 10 determines whether a predetermined specific control execution condition is satisfied. The specific control execution condition is a condition for determining whether to execute the specific control. The driving assistance ECU 10 executes or does not execute the specific control depending on whether the specific control execution condition is satisfied.

[0040] The specific control execution condition is satisfied when the vehicle VA is traveling on a curved section, as shown in Fig. 3. This is because if an EPS abnormality occurs while the vehicle VA is traveling on a curved section, the vehicle VA is more likely to deviate from the target driving line TL (i.e., the center position of the lane), as shown by the arrow ar1.

[0041] The specific control execution condition is a condition related to the curvature CL. In this example, when the vehicle VA is traveling on a left curve, the curvature CL is a positive value, and when the vehicle VA is traveling on a right curve, the curvature CL is a negative value. The specific control execution condition is met when the magnitude (absolute value) of the curvature CL is greater than a predetermined curvature threshold value CLth.

[0042] The specific control is a control for applying a steering torque of a predetermined magnitude to the steering mechanism 50. When the vehicle VA is traveling around a left curve, the driving assistance ECU 10 controls the motor 51 to apply a predetermined positive steering torque Tra (constant value) for turning the steering wheels to the left to the steering mechanism 50. The magnitude of the steering torque Tra is set to be equal to or less than the magnitude of the automatic steering torque Btr calculated in the same situation.

[0043] When the vehicle VA is traveling on a right curve, the driving assistance ECU 10 controls the motor 51 to apply a predetermined negative steering torque Trb (constant value) to the steering mechanism 50 to steer the steering wheels to the right. The magnitude of the steering torque Trb is set to be equal to or less than the magnitude of the automatic steering torque Btr calculated in the same situation. This configuration can reduce the possibility that the vehicle VA will deviate from the center position of the lane.

[0044] On the other hand, when the vehicle VA is traveling on a straight section, the vehicle VA is unlikely to deviate from the target driving line TL (the center position of the lane). Furthermore, if the above-mentioned specific control is executed, the vehicle VA may sway or deviate from the center position of the lane. Therefore, when the specific control execution condition is not satisfied (the vehicle VA is not traveling on a curved section), the driving assistance ECU 10 does not execute the specific control.

[0045] (Activation) Next, a description will be given of the operation of the CPU (referred to as "CPU1") of the EPS·ECU 40. The CPU executes a "steering assist control execution routine" shown in FIG. 4 every time a predetermined time elapses.

[0046] 4 from step 400 and proceeds to step 401 to determine whether or not an EPS abnormality has occurred. If an EPS abnormality has not occurred, the CPU 1 determines "No" in step 401 and proceeds to step 402 to execute normal assist control. After that, the CPU 1 proceeds directly to step 495 to temporarily end this routine.

[0047] On the other hand, if an EPS abnormality has occurred, the CPU 1 judges "Yes" in step 401 and proceeds to step 403 to execute backup assist control. After that, the CPU 1 proceeds directly to step 495 to temporarily end this routine.

[0048] Next, a description will be given of the operation of the CPU (hereinafter referred to as "CPU 2") of the driving assistance ECU 10. The CPU 2 executes an "LKA execution routine" shown in FIG. 5 every time a predetermined time elapses while the ACC is being executed.

[0049] The CPU 2 executes a routine (not shown) at predetermined intervals to receive detection signals or output signals from the various sensors (11 to 15) and the operation switch 16 and store them in the RAM.

[0050] 5 from step 500 and proceeds to step 501, where it is determined whether or not the value of the LKA execution flag X1 is "0." When the value of the LKA execution flag X1 is "1," it indicates that the LKA is in an ON state, and when the value is "0," it indicates that the LKA is in an OFF state. The LKA execution flag X1 is set to "0" in an initialization routine executed by the CPU 2 when an ignition switch (not shown) is changed from the OFF position to the ON position.

[0051] Now, assuming that the operation state of the LKA is in the OFF state, the value of the LKA execution flag X1 is “0.” In this case, the CPU 2 judges “Yes” in step 501 and proceeds to step 502 to judge whether or not the LKA execution condition is satisfied.

[0052] The LKA execution condition is met when both the following conditions A1 and A2 are met. However, another condition may be added as one of the conditions that must be satisfied in order for the LKA execution condition to be met. The same applies to the other conditions described below. (Condition A1): The operation switch 16 is operated to select the ON state of the LKA. (Condition A2): The left lane marking LL and the right lane marking RL are detected up to a distant position from the vehicle VA.

[0053] If the LKA execution condition is not satisfied, the CPU 2 determines "No" in step 502, proceeds directly to step 595, and ends this routine for the time being.

[0054] On the other hand, if the LKA execution condition is satisfied, the CPU 2 determines "Yes" in step 502 and sequentially executes the processes of "step 503 and step 504" described below. After that, the CPU 2 proceeds to step 595 and temporarily ends this routine. Step 503: The CPU 2 sets the value of the LKA execution flag X1 to "1." Step 504: CPU2 executes LKA as described above.

[0055] 5 again from step 500 after LKA has been started, the CPU 2 determines "No" in step 501 and proceeds to step 505. The CPU 2 determines whether or not an EPS abnormality has occurred in step 505. If it is assumed that an EPS abnormality has not occurred, the CPU 2 determines "No" in step 505 and proceeds to step 506, where it determines whether or not a predetermined LKA termination condition is satisfied.

[0056] The LKA termination condition is met when at least one of the following conditions B1 and B2 is met. (Condition B1): The operation state of LKA was changed to the off state by operating the operation switch 16. (Condition B2): The left lane marking LL and the right lane marking RL are no longer detected up to a position far away from the vehicle VA.

[0057] If the LKA end condition is not satisfied, the CPU 2 determines "No" in step 506 and proceeds to step 504 to continue LKA. After that, the CPU 2 proceeds to step 595 to temporarily end this routine.

[0058] Assume that an EPS abnormality occurs during the execution of LKA. In this case, when the CPU 2 starts the routine of FIG. 5 again from step 500, the CPU 2 judges "No" in step 501, judges "Yes" in step 505, and proceeds to step 508. Then, in step 508, the CPU 2 judges whether the specific control execution condition described above is satisfied. If the specific control execution condition is not satisfied, the CPU 2 judges "No" in step 508, proceeds directly to step 595, and temporarily ends this routine. In this case, neither the LKA nor the specific control is executed. This is because the vehicle VA is traveling in a straight traveling lane, and the vehicle VA is unlikely to deviate from the target traveling line TL (i.e., the center position of the lane).

[0059] On the other hand, when the specific control execution condition is satisfied, the CPU 2 determines "Yes" in step 508, proceeds to step 509, and executes the specific control. Note that the CPU 2 continues the specific control as long as an EPS abnormality occurs and the specific control execution condition is satisfied (Yes in step 505 and Yes in step 508).

[0060] Assume that the EPS abnormality is resolved after the specific control is started. In this case, when the CPU 2 starts the routine of Fig. 5 again from step 500, the CPU 2 judges "No" in step 501, judges "No" in step 505, and proceeds to step 506. After that, the CPU 2 proceeds to step 504 and executes LKA. In this way, when the EPS abnormality is resolved, LKA is resumed.

[0061] Thereafter, it is assumed that the LKA end condition is satisfied when the CPU 2 starts the routine of Fig. 5 again from step 500. In this case, the CPU 2 judges "No" at step 501, judges "No" at step 505, judges "Yes" at step 506, and proceeds to step 507. The CPU 2 sets the value of the LKA execution flag X1 to "0". After that, the CPU 2 proceeds to step 595 and temporarily ends this routine. This ends the LKA.

[0062] The first device having the above configuration executes the specific control when the vehicle VA is traveling in a curved section (i.e., when the specific control execution condition is satisfied), thereby preventing the vehicle VA from deviating significantly from the target driving line TL.

[0063] <Second embodiment> Next, a vehicle control device according to a second embodiment (hereinafter, sometimes referred to as the "second device") will be described. The specific control execution condition of the second device is different from that of the first device. In this example, the specific control execution condition is a condition that is met when at least one of the following conditions C1 to C3 is met. All of these are conditions that make it possible to determine whether the vehicle VA is traveling in a curve section. (Condition C1): The magnitude of the yaw rate Yr is greater than a predetermined yaw rate threshold Yrth. (Condition C2): The magnitude of the steering angle θ is greater than a predetermined steering angle threshold θth. (Condition C3): The magnitude of the “automatic steering torque Btr for LKA” calculated immediately before an EPS abnormality occurs is greater than a predetermined steering torque threshold Bth.

[0064] The second device having the above configuration can determine whether or not to execute specific control by using information other than the curvature CL of the driving lane.

[0065] <Third embodiment> Next, a vehicle control device according to a third embodiment (hereinafter, sometimes referred to as a "third device") will be described. The third device determines whether or not to execute specific control in response to the operation of the steering wheel SW by the driver.

[0066] For example, assume that an EPS abnormality occurs when the vehicle VA is traveling around a left curve. However, assume that the driver turns the steering wheel SW to the right to avoid an obstacle on the driving lane just before the EPS abnormality occurs. In this case, the driver is intentionally operating the steering wheel SW. If a steering torque Tra (constant value) that turns the steered wheels to the left is applied to the steering mechanism 50 by the specific control, it will actually interfere with the operation of the steering wheel SW by the driver.

[0067] Therefore, when the specific control execution condition is satisfied, the driving assistance ECU 10 of the third device determines whether or not a predetermined prohibition condition is satisfied. The prohibition condition is satisfied when the value of the steering torque Tr is greater than "0" and the sign of the value of the steering torque Tr is opposite to the sign of the value of the steering torque for specific control (Tra, Trb). For example, when the steering torque Tr is a positive value and the steering torque for specific control is "Trb (i.e., a negative value)", the prohibition condition is satisfied. Furthermore, when the steering torque Tr is a negative value and the steering torque for specific control is "Tra (i.e., a positive value)", the prohibition condition is satisfied.

[0068] The third device having the above configuration does not execute the specific control when the driver intentionally operates the steering wheel SW in the opposite direction to the curve, and the vehicle VA can be moved in the direction intended by the driver without being hindered from operating the steering wheel SW by the driver.

[0069] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0070] In the above-described first to third devices, LKA is executed only while ACC is being executed, but LKA may be executed even when ACC is not being executed. Furthermore, the present invention is not limited to LKA, and can also be applied to a vehicle control device that executes, as driving assistance control, an automatic driving control that automatically changes the steering angle so that the vehicle travels along a predetermined target driving line. [Explanation of symbols]

[0071] 10...driving assistance ECU, 11...steering angle sensor, 12...steering torque sensor, 13...vehicle speed sensor, 14...yaw rate sensor, 15...surroundings sensor, 16...operation switch, 20...engine ECU, 30...brake ECU, 40...EPS ECU.

Claims

[Claim 1] an electric power steering device including a steering mechanism and a motor, and configured to assist an operation of a steering wheel by a driver of a vehicle by driving the motor; a control unit that executes lane keeping control, which is a control for driving the motor to change a steering angle of the steering wheels of the vehicle so as to make the vehicle travel along a target driving line; Equipped with The control unit When an abnormality occurs in the electric power steering device while the lane keeping control is being executed, determining whether a predetermined specific control execution condition that is satisfied when the vehicle is traveling through a curve section is satisfied; When the predetermined specific control execution condition is satisfied, a specific control is executed to drive the motor so as to prevent the vehicle from deviating from the target driving line. It was configured as follows: In the vehicle control device, The control unit The curvature (CL) of the target driving line, the distance (dL) between the target driving line and the center position of the vehicle in the vehicle width direction, and the yaw angle (θL) which is the angle of the longitudinal axis of the vehicle with respect to the target driving line are acquired as control parameters of the lane keeping control, an automatic steering torque (Btr) is calculated in accordance with the control parameters, and the motor is controlled so that an actual torque generated by the motor coincides with the automatic steering torque (Btr), thereby executing the lane keeping control; execute the specific control by controlling the motor so that the actual torque generated by the motor coincides with a steering torque (Tra, Trb) for specific control, the steering torque being equal to or smaller than the automatic steering torque (Btr) calculated when the control parameters of the lane keeping control are the same as the control parameters of the lane keeping control at the current time, the steering torque being a steering torque for steering the steering wheels to the left when the vehicle is traveling on a left curve and a steering torque for steering the steering wheels to the right when the vehicle is traveling on a right curve; Even if an abnormality occurs in the electric power steering device during execution of the lane keeping control, when the vehicle is not traveling in a curved section and the specific control execution condition is not satisfied, the specific control is not executed, Furthermore, when the driver applies a steering torque to steer the steering wheel to the left and the steering torque for the specific control has a value to steer the steering wheel to the right, and when the driver applies a steering torque to steer the steering wheel to the right and the steering torque for the specific control has a value to steer the steering wheel to the left, the specific control is not executed even if an abnormality occurs in the electric power steering device during execution of the lane keeping control and the specific control execution condition is established. It was configured as follows: Vehicle control device.

Images