Vehicle control device

Abstract

The present application relates to a vehicle control device that makes a steering reaction force larger than a reference reaction force when it is determined that there is no possibility that a driver will perform a predetermined steering operation for moving a host vehicle laterally without a change in a final travel direction. In addition, the vehicle control device makes the steering reaction force smaller than the reference reaction force when it is determined that there is the possibility that the driver will perform the predetermined steering operation, and makes an increase rate of the steering reaction force with respect to an increase in the amount of the steering operation larger after a predetermined time point before which the amount of the steering operation in the predetermined steering operation is made maximum than before the predetermined time point after it is determined that there is the possibility that the driver will perform the predetermined steering operation.

Description

Technical Field

[0001] This invention relates to vehicle control devices. Background Technology

[0002] There exists a range (appropriate range) of the amount of steering wheel operation required by the driver to properly navigate a curve. Therefore, a vehicle control device is known that, when the driver's steering wheel operation increases and enters the appropriate range while the vehicle is navigating a curve, increases the reaction force (steering reaction force) applied to the driver's steering wheel operation, thereby making it easier to keep the steering wheel operation within the appropriate range (see Japanese Patent Application Laid-Open No. 2019-209844). Summary of the Invention

[0003] The aforementioned vehicle control device adjusts the steering wheel operation by regulating the steering reaction force when the driver is driving the vehicle along a curve. Such support is desired not only when driving the vehicle along a curve, but also when driving the vehicle in a straight line and when changing lanes. In these situations, a different adjustment of the steering reaction force is required than when driving the vehicle along a curve. However, the aforementioned vehicle driving support device does not handle steering reaction force adjustment in such situations. Furthermore, the appropriate method of steering reaction force adjustment required differs between driving the vehicle in a straight line and changing lanes.

[0004] The object of the present invention is to provide a vehicle control device capable of controlling appropriate steering reaction force in situations where the vehicle is moving laterally without a final change in the vehicle's direction of travel, such as when the vehicle is traveling in a straight line or changing lanes.

[0005] The vehicle control device of the present invention includes a reaction force device that imparts a steering reaction force to a steering operation performed by a driver on the vehicle, and a control device that performs steering reaction force control to control the intensity of the steering reaction force. The control device is configured such that, when performing the steering reaction force control, it imparts a reaction force to the steering operation as the steering reaction force, which increases with the magnitude of the steering operation.

[0006] Furthermore, the control device is configured to perform the following positive steering reaction force control as steering reaction force control: when it is determined that there is no possibility that the driver will perform a predetermined steering operation to move the vehicle laterally without a final change in the vehicle's direction of travel, the steering reaction force is made larger than a reference reaction force; when it is determined that there is a possibility that the driver will perform the predetermined steering operation, the steering reaction force is made smaller than the reference reaction force; and after it is determined that there is a possibility that the driver will perform the predetermined steering operation, the rate of increase of the steering reaction force relative to the amount of the steering operation during the period after a predetermined time point before the amount of the steering operation in the predetermined steering operation becomes maximum is greater than the rate of increase of the steering reaction force relative to the amount of the steering operation during the period before the predetermined time point.

[0007] According to the present invention, when there is no possibility for the driver to perform a predetermined steering operation, such as a steering operation to change lanes (i.e., a steering operation to move the vehicle laterally without a final change in the vehicle's direction of travel) (for example, when the vehicle is traveling in a straight line), a relatively large steering reaction force is applied to the steering operation. Therefore, it is easier for the driver to perform steering operations to maintain the vehicle's straight-line travel.

[0008] On the other hand, according to the present invention, when there is a possibility that the driver will perform a predetermined steering operation, such as a steering operation to change lanes, only a relatively small steering reaction force is applied to the steering operation. Therefore, it is easy for the driver to perform the predetermined steering operation, such as a steering operation to change lanes.

[0009] Furthermore, according to the present invention, after determining that there is a possibility that the pilot will perform a predetermined steering operation, the rate of increase of the steering reaction force relative to the increase in the amount of steering operation at a predetermined time point before the amount of steering operation becomes maximum is greater than the rate of increase of the steering reaction force relative to the increase in the amount of steering operation before the predetermined time point. Therefore, the pilot can more easily maintain the amount of steering operation at its maximum, and also can more easily reduce the amount of steering operation after the amount of steering operation has become maximum.

[0010] Furthermore, in the vehicle control device of the present invention, the control device is configured, for example, to set a target steering operation amount as an amount greater than the amount of steering operation defined by the time-varying (over time) change pattern of the amount of steering operation to be achieved by the predetermined steering operation when it is determined that there is a possibility that the driver will perform the predetermined steering operation. If the actual amount of steering operation is smaller than the target steering operation amount, the steering reaction force is set as the steering reaction force by reducing the reaction force used as the reference, thereby making the steering reaction force smaller than the reaction force used as the reference. Furthermore, the control device is configured, for example, to set a target steering operation amount that is smaller than the amount of steering operation specified by the change mode after the predetermined time point. When the actual amount of steering operation is larger than the target steering operation amount, the control device sets the reaction force obtained by increasing the reaction force used as the reference as the steering reaction force, so that the rate of increase of the steering reaction force relative to the increase of the amount of steering operation in the period after the predetermined time point is greater than the rate of increase of the steering reaction force relative to the increase of the amount of steering operation in the period before the predetermined time point.

[0011] Therefore, when it is determined that there is a possibility that the pilot will perform a predetermined steering operation, the steering reaction force is reduced before the pilot begins the predetermined steering operation. Then, when the amount of steering operation is close to its maximum, the rate of increase of the steering reaction force relative to the increase in the amount of steering operation is increased. Moreover, such steering reaction force is determined based on the time-varying pattern of the amount of steering operation to be achieved by the predetermined steering operation. Therefore, it is possible to increase the likelihood that the pilot will perform the predetermined steering operation in a manner that makes the amount of steering operation change according to the aforementioned pattern.

[0012] Furthermore, in the vehicle control device of the present invention, the control device may be configured to implement the active steering reaction force control as steering reaction force control when it is determined from the driver's request for the implementation of the active steering reaction force control that there is a possibility that the driver will perform the predetermined steering operation; and to implement normal steering reaction force control as steering reaction force control when the predetermined steering operation is performed without the driver's request for the implementation of the active steering reaction force control, in the following manner: the amount of steering operation specified by the variation mode is set as the target steering operation amount; when the actual amount of the steering operation is smaller than the target steering operation amount, the steering reaction force is made smaller than the reference reaction force; and when the actual amount of the steering operation is larger than the target steering operation amount, the steering reaction force is made larger than the reference reaction force.

[0013] Therefore, it is possible to determine whether or not to implement active steering reaction force control in response to the driver's demands.

[0014] The constituent elements of this invention are not limited to the embodiments of the invention described below with reference to the accompanying drawings. Other objects, features, and incidental advantages of the invention will be readily understood from the description of embodiments thereof. Attached Figure Description

[0015] The features, advantages, and technical and industrial significance of typical embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals denote the same elements, and wherein:

[0016] Figure 1 This is a diagram illustrating a vehicle control device according to an embodiment of the present invention and a vehicle (the present vehicle) equipped with the vehicle control device.

[0017] Figure 2 This is a diagram showing a lookup table that specifies the relationship between the steering angle and the reference steering reaction force in normal steering reaction force control.

[0018] Figure 3 This is a diagram showing the vehicle traveling in a straight line.

[0019] Figure 4 This is a diagram showing the vehicle changing lanes.

[0020] Figure 5A This is a diagram showing a lookup table that specifies the relationship between the steering angle and the reference steering reaction force in active straight-line steering reaction force control.

[0021] Figure 5B This is a diagram showing a lookup table that specifies the relationship between the steering angle and the reference steering reaction force in active lane change steering reaction force control.

[0022] Figure 5C This is a diagram showing a lookup table that specifies the relationship between elapsed time and target steering angle in active lane change steering reaction force control.

[0023] Figure 6 This is a graph showing the change of the target steering angle relative to time in active lane change steering reaction force control.

[0024] Figure 7A This is a diagram showing the relationship between the steering angle and the steering reaction force during the first half of a lane change for this vehicle.

[0025] Figure 7BThis is a diagram showing the relationship between the steering angle and the steering reaction force during the latter half of a lane change for this vehicle.

[0026] Figure 8 This is a flowchart illustrating the routines executed by a vehicle control device according to an embodiment of the present invention.

[0027] Figure 9 This is a flowchart illustrating the routines executed by a vehicle control device according to an embodiment of the present invention.

[0028] Figure 10 This is a flowchart illustrating the routines executed by a vehicle control device according to an embodiment of the present invention. Detailed Implementation

[0029] Hereinafter, a vehicle control device according to an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 As shown, the vehicle control device 10 of the embodiment of the present invention is mounted on the vehicle 100. In the following description, the driver of the vehicle 100 will be referred to simply as "driver".

[0030] ECU

[0031] The vehicle control unit 10 includes an ECU 90. ECU is short for Electronic Control Unit. The ECU 90 has a microcomputer as its main component. The microcomputer includes a CPU, ROM, RAM, non-volatile memory, and an interface. The CPU performs various functions by executing instructions, programs, or routines stored in the ROM.

[0032] Traveling device

[0033] In addition, the vehicle 100 is equipped with a running gear 20. The running gear 20 includes a drive unit 21, a braking unit 22, and a steering unit 23.

[0034] drive unit

[0035] The drive unit 21 is a device that outputs additional driving torque (driving force) to the vehicle 100 to make it move; for example, it is an internal combustion engine or a motor. The drive unit 21 is electrically connected to the ECU 90. The ECU 90 can control the driving torque output from the drive unit 21 by controlling the operation of the drive unit 21.

[0036] Braking device

[0037] Braking device 22 is a device that outputs additional braking torque (braking force) to brake the vehicle 100, for example, a brake system. Braking device 22 is electrically connected to ECU 90. ECU 90 can control the braking torque output from braking device 22 by controlling the operation of braking device 22.

[0038] steering gear

[0039] The steering device 23 is a device that outputs steering torque (steering force) to the vehicle 100 for steering purposes; for example, it is a power steering system. The steering device 23 is electrically connected to the ECU 90. The ECU 90 can control the steering torque output from the steering device 23 and the steering reaction force, which will be described later, by controlling the operation of the steering device 23.

[0040] Sensors, etc.

[0041] Furthermore, the vehicle 100 is equipped with an accelerator pedal 31, an accelerator pedal operation sensor 32, a brake pedal 33, a brake pedal operation sensor 34, a steering wheel 35, a steering shaft 36, a steering angle sensor 37, a steering torque sensor 38, a vehicle speed detection device 41, a turn signal control lever 42, an active steering reaction force support switch 43, a turn signal 50, a surrounding information detection device 60, and a road information detection device 70.

[0042] Accelerator pedal operation sensor

[0043] Accelerator pedal operation amount sensor 32 is a sensor that detects the operation amount of accelerator pedal 31 and is electrically connected to ECU 90. Accelerator pedal operation amount sensor 32 sends the detected operation amount of accelerator pedal 31 to ECU 90. ECU 90 obtains the operation amount of accelerator pedal 31 as accelerator pedal operation amount AP based on this information. ECU 90 obtains the required drive torque (required drive force) based on accelerator pedal operation amount AP and the driving speed of vehicle 100, and controls the operation of drive unit 21 in such a way that a drive torque equivalent to the required drive torque is supplied from drive unit 21 to vehicle 100 (in particular, drive wheels of vehicle 100).

[0044] Brake pedal operation sensor

[0045] The brake pedal operation amount sensor 34 is a sensor that detects the operation amount of the brake pedal 33 and is electrically connected to the ECU 90. The brake pedal operation amount sensor 34 sends information about the detected operation amount of the brake pedal 33 to the ECU 90. Based on this information, the ECU 90 obtains the operation amount of the brake pedal 33 as the brake pedal operation amount BP. Based on the brake pedal operation amount BP, the ECU 90 obtains the required braking torque (required braking force) and controls the operation of the brake device 22 in such a way that a braking torque equivalent to the required braking torque is applied from the brake device 22 to the vehicle 100 (in particular, the wheels of the vehicle 100).

[0046] Steering angle sensor

[0047] The steering angle sensor 37 is a sensor that detects the rotation angle of the steering shaft 36 relative to the neutral position, and is electrically connected to the ECU 90. The steering angle sensor 37 sends the detected rotation angle information of the steering shaft 36 to the ECU 90. The ECU 90 obtains the rotation angle of the steering shaft 36 as the steering angle θ based on this information.

[0048] Steering torque sensor

[0049] The steering torque sensor 38 is a sensor that detects the torque input by the driver to the steering shaft 36 via the steering wheel 35, and is electrically connected to the ECU 90. The steering torque sensor 38 sends the detected torque information to the ECU 90. Based on this information, the ECU 90 obtains the torque input by the driver to the steering shaft 36 via the steering wheel 35 as the driver input torque.

[0050] The ECU 90 obtains the required steering torque based on the steering angle θ, the driver's input torque, and the vehicle 100's speed, and controls the operation of the steering device 23 in such a way that a steering torque equivalent to the required steering torque is applied from the steering device 23 to the vehicle 100 (specifically, the steering wheel of the vehicle 100), and a reaction force equivalent to the target steering reaction force RFtgt set as described later is applied to the steering wheel 35 (driver's steering wheel operation). Therefore, in this example, the steering device 23 includes a reaction force device that applies a steering reaction force to the driver's steering wheel operation (steering operation) of the vehicle 100.

[0051] Vehicle speed detection device

[0052] The vehicle speed detection device 41 is a device for detecting the driving speed of the vehicle 100, such as a wheel speed sensor. The vehicle speed detection device 41 is electrically connected to the ECU 90. The vehicle speed detection device 41 sends the detected driving speed information of the vehicle 100 to the ECU 90. The ECU 90 obtains the driving speed of the vehicle 100 as the vehicle speed V100 based on this information.

[0053] Turn signal lever

[0054] The turn signal control lever 42 is a lever operated by the driver to activate the turn signal 50, and is electrically connected to the ECU 90. When the turn signal control lever 42 is operated from the neutral position to the right turn position, the ECU 90 activates (flashes) the turn signal 50 located at the right front corner and the right rear corner of the vehicle 100. On the other hand, when the turn signal control lever 42 is operated from the neutral position to the left turn position, the ECU 90 activates (flashes) the turn signal 50 located at the left front corner and the left rear corner of the vehicle 100.

[0055] Active steering reaction force support switch

[0056] The active steering reaction force support switch 43 is a switch operated by the driver to request the implementation of active steering reaction force control (described later), and is electrically connected to the ECU 90. When the active steering reaction force support switch 43 is operated and set to the ON position, the ECU 90 determines that the implementation of active steering reaction force control is requested.

[0057] Surrounding Information Detection Device

[0058] The surrounding information detection device 60 is a device for detecting information about the surroundings of the vehicle 100. In this example, it includes an electromagnetic wave sensor 61 and an image sensor 62. The electromagnetic wave sensor 61 is, for example, a radar sensor (millimeter-wave radar, etc.). The image sensor 62 is, for example, a camera. In addition, the surrounding information detection device 60 may also include an ultrasonic sensor (gap sonar) or an optical sensor (LiDAR).

[0059] radio wave sensor

[0060] The radio wave sensor 61 is electrically connected to the ECU 90. The radio wave sensor 61 transmits radio waves and receives radio waves reflected from objects (reflected waves). The radio wave sensor 61 sends information (detection result) related to the transmitted and received radio waves (reflected waves) to the ECU 90. In other words, the radio wave sensor 61 detects objects present in the vicinity of the vehicle 100 and sends information (detection result) related to the detected objects to the ECU 90. The ECU 90 uses this information (radio wave information) to obtain information related to objects present in the vicinity of the vehicle 100 as perimeter detection information IS. Furthermore, in this example, the objects are vehicles, motorized two-wheelers, bicycles, and people, etc.

[0061] Image sensor

[0062] Image sensor 62 is also electrically connected to ECU 90. Image sensor 62 captures images of the surroundings of vehicle 100 and sends information related to the captured images to ECU 90. Based on this information (camera image information), ECU 90 obtains information related to the surroundings of vehicle 100 as surroundings detection information IS.

[0063] Road information detection device

[0064] The road information detection device 70 includes a GPS device 71 and a map information database 72.

[0065] GPS device

[0066] GPS device 71 is a device that receives so-called GPS signals and is electrically connected to ECU 90. ECU 90 obtains GPS signals via GPS device 71. ECU 90 can obtain the current location P100 of its vehicle 100 based on the obtained GPS signals.

[0067] Map Information Database

[0068] Map information database 72 is a database that stores map information, including information related to roads, and is electrically connected to ECU 90. ECU 90 obtains information related to the road on which the vehicle 100 is currently traveling from the current position P100 of the vehicle 100 as road information IR.

[0069] Overview of vehicle control unit operation

[0070] Next, a summary of the operation of the vehicle control device 10 will be given.

[0071] Normal steering reaction force control

[0072] When there is no requirement to implement active steering reaction force control, the vehicle control device 10 implements normal steering reaction force control as a steering reaction force control to control the reaction force (steering reaction force) of the driver's operation of the steering wheel 35 (steering wheel operation, steering operation).

[0073] Typically, steering reaction force control is based on setting a target value (target steering reaction force RFtgt) for the steering reaction force based on the steering angle θ (the amount of steering operation), and then applying a steering reaction force (normal steering reaction force) equivalent to the target steering reaction force RFtgt to the steering wheel operation. More specifically, it applies a steering reaction force (normal steering reaction force) that increases with the steering angle θ to the steering wheel operation.

[0074] Vehicle control unit 10 stores, for example Figure 2 As shown by the solid line L1, a lookup table defining the relationship between the steering angle θ and the target steering reaction force RFtgt is used as the lookup table for setting the target steering reaction force RFtgt in normal steering reaction force control. Furthermore, when performing normal steering reaction force control, the vehicle control unit 10 applies the steering angle θ to this lookup table to obtain the steering reaction force (reference steering reaction force RFb) that should be applied to the steering wheel 35 (steering wheel operation), and sets this reference steering reaction force RFb as the target steering reaction force RFtgt, so that a steering reaction force (normal steering reaction force) equivalent to this target steering reaction force RFtgt is applied from the steering unit 23 to the steering wheel 35 to control the operation of the steering unit 23.

[0075] Furthermore, when the driver applies a force to the steering wheel 35 to rotate it clockwise (right turn), the steering device 23 is controlled to operate in a manner that applies a force to rotate the steering wheel 35 counterclockwise (left turn) as a steering reaction force. Conversely, when the driver applies a force to the steering wheel 35 to rotate it counterclockwise (left turn), the steering device 23 is controlled to operate in a manner that applies a force to rotate the steering wheel 35 clockwise (right turn) as a steering reaction force.

[0076] Alternatively, the vehicle control device 10 can also be configured to replace the use of Figure 2 Instead of using a lookup table to obtain the reference steering reaction force RFb, the vehicle control unit 10 uses a formula that defines the relationship between the steering angle θ and the reference steering reaction force RFb to obtain (calculate) the reference steering reaction force RFb.

[0077] Active steering reaction force control

[0078] On the other hand, when active steering reaction force control is required, the vehicle control device 10 implements active steering reaction force control as steering reaction force control. At this time, if the vehicle control device 10 determines that there is no possibility of the driver changing lanes (lane change implementation possibility), that is, if... Figure 3 As shown, under the presumption that the driver intends to make the vehicle 100 travel along a straight road (straight-line travel), active straight-line travel steering reaction force control is implemented as active steering reaction force control. On the other hand, as... Figure 4 As shown, when the vehicle control device 10 determines that there is a possibility that the driver may change the lane of the vehicle 100 (the possibility of lane change), it implements active lane change steering reaction force control as active steering reaction force control.

[0079] In addition, Figure 3 and Figure 4 In the attached diagram, the lane indicated by reference numeral LN2 is the lane adjacent to the right side of lane LN1, and is a lane where the vehicles in this lane travel in the same direction as the vehicles in lane LN1 (right adjacent parallel lane). Additionally, the lanes indicated by reference numerals LN3 and LN4 are respectively the opposite lanes to lane LN1 and the right adjacent parallel lane LN2.

[0080] Furthermore, the operation of the vehicle control device 10 will be explained below as an example of a scenario where the driver changes lanes by moving the vehicle 100 from lane LN1 (the lane in which the vehicle 100 is currently traveling) to the adjacent lane on the right (a lane whose direction of travel is the same as that of lane LN1 and is adjacent to the right side of lane LN1). In addition, as a scenario where the driver changes lanes by moving the vehicle 100, there are also scenarios where the vehicle 100 changes lanes by moving from lane LN1 to the adjacent lane on the left (a lane whose direction of travel is the same as that of lane LN1 and is adjacent to the left side of lane LN1), where the vehicle 100 enters the main highway from a gentle curve connected to the main highway, and where the vehicle 100 enters the dedicated right turn lane from lane LN1.

[0081] Furthermore, in situations where the vehicle 100 performs the same action as when changing lanes, there are also situations where the vehicle 100 moves closer to the side of the road (next to lane LN1) as an emergency vehicle such as an ambulance approaches. The vehicle control device 10 can also be applied to such situations. Therefore, the vehicle control device 10 can be applied not only to situations where the vehicle 100 turns right or left and moves laterally with a final change in the direction of travel of the vehicle 100 when the vehicle 100 is turned by steering wheel operation, but also to situations where the vehicle 100 moves laterally without a final change in the direction of travel of the vehicle 100 when the vehicle 100 is turned by steering wheel operation.

[0082] Furthermore, in this example, the vehicle control device 10 determines that a lane change is possible when the turn signal 50 is activated and there is an adjacent parallel lane in the direction of rotation of the vehicle 100 indicated by the turn signal 50; otherwise, it determines that a lane change is not possible. Here, an adjacent parallel lane is a lane adjacent to the current lane LN1, and is a lane in which the vehicles traveling in that lane travel in the same direction as the vehicles in the current lane LN1. Figure 4 In the example shown, the turning direction of the vehicle 100 indicated by turn signal 50 is a right turn, therefore the adjacent parallel lane is the right adjacent parallel lane LN2. Furthermore, the existence of an adjacent parallel lane in the turning direction of the vehicle 100 indicated by turn signal 50 is determined based on the surrounding detection information IS and / or road information IR.

[0083] In addition, the vehicle control device 10 may also be configured to determine whether there is a possibility of lane change by means other than those described above.

[0084] For example, the vehicle control device 10 may be configured to determine that a lane change is likely if the number of times the driver checks the exterior and interior rearview mirrors of the vehicle 100 increases, and to determine that a lane change is not likely if this is not the case. In this case, whether the number of times the driver checks the exterior and interior rearview mirrors of the vehicle 100 increases is determined based on images captured by a camera (a so-called driver monitoring camera) positioned to capture at least the driver's upper body.

[0085] Alternatively, the vehicle control device 10 may be configured to determine that a lane change is possible when a preceding vehicle traveling at a speed considerably slower than the current vehicle speed V100 is detected, and to determine that a lane change is not possible when such a vehicle is not detected. In this case, the determination of whether a preceding vehicle traveling at a speed considerably slower than the current vehicle speed V100 has been detected is based on the surrounding detection information IS.

[0086] Active straight-line steering reaction force control

[0087] The active straight-line steering reaction force control, like the normal steering reaction force control, is based on setting a target value (target steering reaction force RFtgt) for the steering reaction force at the steering angle θ, and applying a steering reaction force (active straight-line steering reaction force) equivalent to the target steering reaction force RFtgt to the steering wheel 35 (steering wheel operation). More specifically, it applies a steering reaction force (active straight-line steering reaction force) to the steering wheel 35 that increases with the steering angle θ. However, the steering reaction force (active straight-line steering reaction force) applied through this active straight-line steering reaction force control is greater than the steering reaction force (normal steering reaction force) applied through the normal steering reaction force control when the steering angle θ is the same.

[0088] That is, the vehicle control device 10 is configured to increase the steering reaction force when, although the implementation of active steering reaction force control is required, it is determined that there is no possibility of lane change implementation, compared to the case where the implementation of active steering reaction force control is not required.

[0089] Vehicle control unit 10 stores, for example Figure 5AA lookup table, as shown by the solid line L2, defines the relationship between the steering angle θ and the reference steering reaction force RFb. This table is used to set the target steering reaction force RFtgt when active steering reaction force control is required. Furthermore, when the vehicle control device 10 performs active straight-line steering reaction force control, it applies the steering angle θ to this lookup table to obtain a reference value (reference steering reaction force RFb, the reference reaction force) that should be applied to the steering wheel 35 (steering wheel operation). This reference steering reaction force RFb is set as the target steering reaction force RFtgt, so that a steering reaction force (active straight-line steering reaction force) equivalent to this target reaction force RFtgt is applied from the steering device 23 to the steering wheel 35 to control the operation of the steering device 23. Furthermore, in Figure 5A In the diagram, the dashed line L1 represents the relationship between the steering angle θ and the reference steering reaction force RFb used to set the target steering reaction force RFtgt during normal steering reaction force control (i.e., Figure 2 The line showing the relationship.

[0090] Therefore, compared with the usual steering reaction force control, it is difficult for the driver to increase the amount of steering wheel operation. Thus, it is easy to keep the amount of steering wheel operation near zero and to maintain the rotational position of the steering wheel 35 used to make the vehicle travel in a straight line at 100.

[0091] Furthermore, the vehicle control device 10 can also be configured to replace the use of Figure 5A Instead of using a lookup table to obtain the reference steering reaction force RFb, the vehicle control unit 10 uses a formula that defines the relationship between the steering angle θ and the reference steering reaction force RFb to obtain (calculate) the reference steering reaction force RFb.

[0092] Active lane change steering reaction force control

[0093] In addition, the active lane change steering reaction force control is based on setting a target value (target steering reaction force RFtgt) of steering reaction force based on steering angle θ and steering angle difference Δθ, and applying a steering reaction force (active lane change steering reaction force) equivalent to the target steering reaction force RFtgt to the steering wheel 35 (steering wheel operation). More specifically, it is applying a steering reaction force (active lane change steering reaction force) set to the value as described below to the steering wheel 35.

[0094] That is, the vehicle control device 10 stores, for example, Figure 5BAs shown by the solid line L3, a lookup table defining the relationship between the steering angle θ and the reference steering reaction force RFb is used as the lookup table for setting the target steering reaction force RFtgt in active lane change steering reaction force control. Furthermore, when performing active lane change steering reaction force control, the vehicle control unit 10 applies the steering angle θ to this lookup table to obtain the reference value (reference steering reaction force RFb, the reference reaction force) of the steering wheel 35 (steering wheel operation) that should be applied.

[0095] Furthermore, in this example, the reference steering reaction force RFb is used in active lane change steering reaction force control to obtain the reference steering reaction force. Figure 5B The lookup table shown is used in normal steering reaction force control to obtain the reference steering reaction force RFb. Figure 2 The lookup tables shown are the same, but if the reference steering reaction force RFb relative to the same steering angle θ is from Figure 5A If the reference steering reaction force RFb obtained from the lookup table shown is below, then it can also be compared with... Figure 2 The lookup tables shown are different.

[0096] Moreover, the vehicle control unit 10 stores, for example, Figure 5C As shown by the solid line Lg, a lookup table is defined for the relationship between the elapsed time (elapsed time T) from a predetermined time point (lane change implementation determination time point tLC) and the target steering angle θtgt (target steering operation amount). This lookup table is used to set the target steering reaction force RFtgt in active lane change steering reaction force control. Furthermore, when performing active lane change steering reaction force control, the vehicle control device 10 uses the elapsed time T to obtain the target steering angle θtgt from this lookup table, obtains the difference between the actual steering angle θ at that time point and the target steering angle θtgt as the steering angle difference Δθ, and obtains the steering reaction force corresponding to this steering angle difference Δθ as the steering reaction force adjustment value RFa. In this case, the vehicle control device 10 obtains a steering reaction force whose value increases as the steering angle difference Δθ increases as the steering reaction force adjustment value RFa.

[0097] Here, when the actual steering angle is smaller than the target steering angle θtgt, a positive steering reaction force adjustment value RFa is obtained; when the actual steering angle is larger than the target steering angle θtgt, a negative steering reaction force adjustment value RFa is obtained; and when the actual steering angle is equal to the target steering angle θtgt, the obtained steering reaction force adjustment value RFa is zero.

[0098] In addition, the lane change determination time point tLC is the time point at which the vehicle control device 10 determines that there is a possibility of lane change implementation.

[0099] The vehicle control unit 10 sets the target steering reaction force RFtgt (RFtgt = RFb - RFa) as the value obtained by subtracting the steering reaction force adjustment value RFa from the reference steering reaction force RFb obtained as described above, and outputs a steering reaction force (active lane change steering reaction force) equivalent to this target steering reaction force RFtgt from the steering device 23 to the steering wheel 35. Therefore, regarding the target steering reaction force RFtgt, when the actual steering angle is smaller than the target steering angle θtgt, it is set to a value smaller than the reference steering reaction force RFb, and when the actual steering angle is larger than the target steering angle θtgt, it is set to a value larger than the reference steering reaction force RFb.

[0100] In addition, Figure 5C In the diagram, the dotted line Lb represents the reference steering angle profile Pb. In this example, the guide steering angle profile Pg is set based on the reference steering angle profile Pb.

[0101] The reference steering angle profile Pb is the time-varying pattern of the steering angle θ (the amount of steering wheel operation, the amount of steering operation) that should be achieved when the vehicle changes lanes to a parallel adjacent lane. For example, it is the steering angle change pattern when the driver of the vehicle 100 has changed lanes in the past, or the steering angle change pattern when a driver with high driving skills changes lanes, or the target steering angle change pattern set by the control program for enabling the vehicle control device 10 to autonomously change lanes of the vehicle 100.

[0102] like Figure 5C As shown, the guiding steering angle profile Pg is obtained by shrinking the reference steering angle profile Pb over the same elapsed time T in such a way that the target steering angle θtgt obtained from the guiding steering angle profile Pg is smaller than the steering angle θ obtained from the reference steering angle profile Pb.

[0103] When the vehicle control device 10 determines that there is a possibility of lane change when it requests the implementation of active steering reaction force control, it stops active straight-line driving steering reaction force control and starts active lane change steering reaction force control after a predetermined time (control start time Tstart) has elapsed from that time.

[0104] In this example, the control start time Tstart is set to be a time (control advance time Ta) shorter than the estimated time from the time when the possibility of lane change is determined to the time from when the driver actually begins to perform steering wheel operation (predetermined steering operation) to change lanes in the vehicle 100.

[0105] Therefore, in this example, as Figure 6 As shown, when the target steering angle θtgt is set based on the reference steering angle profile Pb, this setting begins at time t61. However, when the target steering angle θtgt is set based on the guide steering angle profile Pg, this setting begins at time t60, which is earlier than time t61. In other words, the setting of the target steering angle θtgt based on the guide steering angle profile Pg begins at a timing earlier than the setting of the target steering angle θtgt based on the reference steering angle profile Pb. Furthermore, when the target steering angle θtgt is set based on the guide steering angle profile Pg, the timing when the target steering angle θtgt is greater than zero is earlier compared to the case where the target steering angle θtgt is set based on the reference steering angle profile Pb.

[0106] Furthermore, at time t62, which is later than the time t60 when the target steering angle θtgt is set based on the guide steering angle profile Pg and a predetermined time later than the time t61 when the target steering angle θtgt is set based on the reference steering angle profile Pb, the target steering angle θtgt set based on the guide steering angle profile Pg is smaller than the target steering angle θtgt set based on the reference steering angle profile Pb.

[0107] Based on the above, according to the vehicle control device 10, as long as there is no possibility of lane change, that is, as long as the driver makes the vehicle 100 travel in a straight line, a relatively large steering reaction force is applied to the steering wheel 35 (steering wheel operation). Therefore, the driver is more likely to keep the steering wheel 35 in a neutral position in order to make the vehicle 100 travel in a straight line.

[0108] Furthermore, when it is determined that there is a possibility of lane change, before the driver begins to operate the steering wheel to change lanes, a target steering angle θtgt (greater than zero) based on the guide steering angle profile Pg is set. Therefore, as... Figure 7A As shown by line L4 (solid line), when comparing at the same steering angle, the steering reaction force (active lane change steering reaction force) is greater than that obtained by... Figure 7A The line L1, indicated by the dashed midpoint, represents a smaller steering reaction force output by normal steering reaction force control (normal steering reaction force), which is, of course, smaller than that produced by... Figure 7A The line L2, which is marked with the midpoint, indicates a small steering reaction force output for positive straight-line steering reaction force control (positive straight-line steering reaction force). Therefore, the steering reaction force decreases before the driver begins to operate the steering wheel to change lanes, allowing the driver to operate the steering wheel smoothly.

[0109] Furthermore, when the driver changes lanes in the vehicle 100, the steering wheel 35 is operated as follows: The driver gradually increases the amount of steering wheel operation (steering wheel operation amount) while changing lanes in the vehicle 100. When the steering angle θ (the amount of steering operation) reaches its maximum (steering angle θ reaches its maximum steering angle θmax), the driver maintains the steering wheel 35 at that position. When the vehicle 100 finishes entering a parallel adjacent lane, the driver gradually decreases the amount of steering wheel operation until the steering wheel 35 reaches a neutral position and the steering angle θ becomes zero. When the vehicle 100 begins to travel in a straight line, the driver maintains the steering wheel 35 in the neutral position.

[0110] In the event that the driver operates the steering wheel 35 to change lanes for the vehicle 100, according to the vehicle control device 10, from the time the driver begins steering wheel operation until a predetermined time has elapsed, the following will be implemented: Figure 7A The steering reaction force, as shown by the solid line L4, is applied to the steering wheel 35 (steering wheel operation) according to the steering angle θ, but after a predetermined time, it will... Figure 7B The steering reaction force, as shown by the solid line L5, is imparted to the steering wheel 35 (steering wheel operation) according to the steering angle θ.

[0111] Therefore, after the driver begins steering wheel operation, and after a predetermined time has elapsed and the steering angle θ approaches the maximum steering angle θmax, the rate of increase in steering reaction force relative to the increase in steering wheel operation is greater. Thus, the driver can more easily maintain the steering wheel at 35° when the steering angle θ reaches the maximum steering angle θmax. Furthermore, after the vehicle 100 enters a parallel adjacent lane, the driver can more easily maneuver the steering wheel at 35° to a neutral position.

[0112] Furthermore, when it is determined that there is a possibility of lane change, the steering reaction force is reduced before the driver begins to perform steering wheel operation (predetermined steering operation) to change lanes in the vehicle 100. Then, when the steering angle approaches the maximum steering angle θmax, the rate of increase of the steering reaction force (target steering angle θtgt) relative to the increase of the steering angle is increased. Moreover, such steering reaction force (target steering angle θtgt) is determined based on the time-varying pattern of the steering angle that should be achieved in the lane change of the vehicle 100 (reference steering angle profile Pb). Therefore, it is possible to increase the likelihood that the driver will perform steering wheel operation (predetermined steering operation) to change lanes in the vehicle 100 in a manner that changes the steering angle along the aforementioned pattern (reference steering angle profile Pb).

[0113] Furthermore, the vehicle control device 10 can also be configured to replace the use of Figure 5CInstead of using the lookup table shown, the target steering angle θtgt is obtained by using the calculation formulas shown in Equations 1, 2 and 3 below.

[0114]

[0115] A=θmax·K1…(2)

[0116]

[0117] In Equation 1, "MAX" is the MAX function; in Equation 1, "A" is calculated from Equation 2; in Equation 2, "θmax" is the maximum steering angle in the reference steering angle profile Pb; and "K1" is a constant set to a predetermined value smaller than "1". In Equation 1, It is calculated from Equation 3, in which "T" is the estimated time from the lane change implementation determination time point tLC (the time point at which the possibility of lane change implementation is determined) to the time when the driver begins to operate the steering wheel to change the lane of the vehicle 100, and "K2" is a constant set to a predetermined value greater than "0".

[0118] In this case, the vehicle control unit 10 uses the elapsed time T as a variable to obtain (calculate) the target steering angle θtgt from Equations 1 to 3.

[0119] Alternatively, when a lane change is deemed possible during normal steering reaction force control, a target steering angle θtgt is obtained from the reference steering angle profile Pb. The difference between the actual steering angle θ and the target steering angle θtgt at that time point is taken as the steering angle difference Δθ, and the steering reaction force corresponding to this steering angle difference Δθ is taken as the steering reaction force adjustment value RFa. In this case, the vehicle control device 10 takes the steering reaction force with a larger value as the steering angle difference Δθ is as the steering reaction force adjustment value RFa. Furthermore, when the steering reaction force adjustment value RFa is obtained in this way, when calculating the target steering angle θtgt obtained from the reference steering angle profile Pb from Equation 1 above, the constant K1 is set to "1", and the constant K2 is set to "0".

[0120] The specific operation of vehicle control devices

[0121] Next, the specific operation of the vehicle control unit 10 will be explained. The CPU of the ECU 90 of the vehicle control unit 10 executes according to a predetermined calculation cycle. Figure 8 The example shown. Therefore, at the predetermined time, the CPU starts from... Figure 8 The routine shown begins processing at step 800, which leads to step 805, where it is determined whether active steering reaction force control is required.

[0122] If the CPU determines "yes" in step 805, the process proceeds to step 810 and execution begins. Figure 9 The example shown. Therefore, when the CPU causes processing to proceed to step 810, it from... Figure 9 The routine shown begins processing from step 900, leading to step 905, where the value of the lane change determination flag X1 is determined to be "1". The lane change determination flag X1 is a flag indicating whether there is a possibility of lane change. This value is set to "1" when it is determined that there is a possibility of lane change, and is set to "0" after the lane change of vehicle 100 ends following the setting of this value to "1", or after the setting of this value to "1" and the determination that there is no possibility of lane change.

[0123] If the CPU determines "yes" in step 905, the process proceeds to step 910, where it determines whether the elapsed time T has exceeded the control start time Tstart.

[0124] If the CPU determines "yes" in step 910, the process proceeds to step 915, utilizing... Figure 5C The lookup table shown is used to set the target steering angle θtgt. Next, the CPU proceeds to step 920, where the steering reaction force adjustment value RFa is obtained (calculated) based on the target steering angle θtgt set in step 915. Then, the CPU proceeds to step 925, utilizing... Figure 5B The reference steering reaction force RFb is obtained from the lookup table shown. Next, the CPU proceeds to step 930, setting the target steering reaction force RFtgt based on the steering reaction force adjustment value RFa obtained in step 920 and the reference steering reaction force RFb obtained in step 925. Next, the CPU proceeds to step 935, controlling the operation of the steering device 23 such that a steering reaction force equivalent to the target steering reaction force RFtgt set in step 930 is output from the steering device 23 to the steering wheel 35. Next, the CPU proceeds to step 995. Figure 8 Step 895 of the example shown temporarily ends the processing of this example.

[0125] On the other hand, if the CPU determines "no" in step 905 or step 910, the process proceeds to step 940, utilizing... Figure 5AThe reference steering reaction force RFb is obtained from the lookup table shown. Next, the CPU proceeds to step 945, setting the reference steering reaction force RFb obtained in step 940 as the target steering reaction force RFtgt. Then, the CPU proceeds to step 950, controlling the operation of the steering device 23 such that a steering reaction force equivalent to the target steering reaction force RFtgt set in step 945 is output from the steering device 23 to the steering wheel 35. Next, the CPU proceeds to step 995... Figure 8 Step 895 of the example shown temporarily ends the processing of this example.

[0126] In addition, the CPU Figure 8 If step 805 of the example shown is determined to be "no", the process proceeds to step 815 and is executed. Figure 10 The example shown. Therefore, when the CPU causes processing to proceed to step 815, it from... Figure 10 The example shown begins processing from step 1000, causing the process to proceed to step 1005, utilizing... Figure 2 The reference steering reaction force RFb is obtained from the lookup table shown. Next, the CPU causes the process to proceed to step 1010, setting the reference steering reaction force RFb obtained in step 1005 as the target steering reaction force RFtgt. Next, the CPU causes the process to proceed to step 1015, controlling the operation of the steering device 23 such that a steering reaction force equivalent to the target steering reaction force RFtgt set in step 1010 is output from the steering device 23 to the steering wheel 35. Next, the CPU causes the process to proceed via step 995. Figure 8 Step 895 of the example shown temporarily ends the processing of this example.

[0127] The above describes the specific operation of the vehicle control device 10.

[0128] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention.

Claims

1. A vehicle control device provided with a reaction force device that imparts a steering reaction force to a steering operation on a host vehicle performed by a driver, and a control device that executes control of the strength of the steering reaction force, the control device being configured to impart, as the steering reaction force, a reaction force that increases the more the amount of the steering operation is increased, to the steering operation when the steering reaction force control is executed, the vehicle control device being characterized in that the control device is configured to execute, as the steering reaction force control, an aggressive steering reaction force control in which: when it is determined that there is no possibility that the driver will perform a predetermined steering operation for moving the host vehicle in a lateral direction without a final change in the traveling direction of the host vehicle, the steering reaction force is made greater than a reaction force serving as a reference, when it is determined that there is a possibility that the driver will perform the predetermined steering operation, the steering reaction force is made smaller than the reaction force serving as the reference, an increase rate of the steering reaction force with respect to an increase in the amount of the steering operation is made greater in a period after a predetermined time point at which the amount of the steering operation in the predetermined steering operation becomes greatest, than in a period before the predetermined time point, the control device is configured so that when it is determined that there is a possibility that the driver will perform the predetermined steering operation, an amount greater than an amount of the steering operation prescribed by a temporal change pattern of the amount of the steering operation to be achieved by the predetermined steering operation is set as a target steering operation amount, and in a case where an actual amount of the steering operation is smaller than the target steering operation amount, the steering reaction force is made smaller than the reaction force serving as the reference by setting a reaction force obtained by reducing the reaction force serving as the reference as the steering reaction force, after the predetermined time point, an amount smaller than the amount of the steering operation prescribed by the change pattern is set as the target steering operation amount, and in a case where the actual amount of the steering operation is greater than the target steering operation amount, the increase rate of the steering reaction force with respect to the increase in the amount of the steering operation is made greater in the period after the predetermined time point than in the period before the predetermined time point by setting a reaction force obtained by increasing the reaction force serving as the reference as the steering reaction force.

2. The vehicle control device according to claim 1, the control device being configured so that in a case where it is determined that there is a possibility that the driver will perform the predetermined steering operation from when the aggressive steering reaction force control is requested by the driver, the aggressive steering reaction force control is executed as the steering reaction force control, In a case where the predetermined steering operation is performed without the implementation of the active steering reaction force control requested from the driver, the following normal steering reaction force control is implemented as the steering reaction force control, which sets the amount of steering operation prescribed by the change mode as the target steering operation amount, makes the steering reaction force smaller than the reaction force as the reference in a case where the actual amount of steering operation is smaller than the target steering operation amount, and makes the steering reaction force larger than the reaction force as the reference in a case where the actual amount of steering operation is larger than the target steering operation amount.

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