Vehicle driving support control device, vehicle driving support control method, and program

Abstract

The invention provides a vehicle driving assistance control device, a vehicle driving assistance control method, and a program. A driving assistance control device is provided with a controller for executing, as driving assistance control, steering assistance control (lane maintenance control) for automatically changing the steering angle of a vehicle, and acceleration assistance control (follow-up inter-vehicle distance control) for automatically changing the acceleration of the vehicle, on the basis of the traveling situation of the vehicle. The controller learns a steering preference level indicating a degree of preference of the driver with respect to steering, and changes an intensity of steering assist in the steering assist control on the basis of the learned steering preference level. The controller learns an acceleration hobby level indicating the degree of acceleration hobby of the driver, and changes the intensity of the acceleration assist in the acceleration assist control on the basis of the learned acceleration hobby level.

Description

Technical Field

[0001] The present invention relates to a driving assistance control device, a driving assistance control method, and a program thereof for assisting a driver in driving the vehicle. Background Art

[0002] Conventionally, there are known driving assistance control devices that perform various driving assistance controls, including lane keeping control and following distance control. For example, one conventional driving assistance control device changes the target travel line in lane keeping control and the target distance in following distance control based on the driver's preference (see, for example, Japanese Patent Application Laid-Open No. 2020-26154). Summary of the Invention

[0003] However, the conventional devices described above cannot adapt the steering feel (the strength (intensity level) of the steering assist) and / or the acceleration feel (the strength of the acceleration assist) in the driving assist control to the driver's preference.

[0004] The present invention is made to solve the related problems. Specifically, one object of the present invention is to provide a driving assistance control device, a driving assistance control method, and a program thereof that can make the driving experience in driving assistance control as close to the driver's preference as possible.

[0005] One embodiment of a vehicle driving assistance control device according to the present invention comprises a controller (10), wherein the controller (10) executes at least one of a steering assistance control and an acceleration assistance control as driving assistance control, wherein the steering assistance control determines a steering control amount (S440) for automatically changing an actual steering angle of the own vehicle based on at least a driving condition of the own vehicle, and performs steering assistance (S441) for changing the actual steering angle based on the steering control amount. Figure 4 ), the acceleration assist control determines a target acceleration for automatically changing the actual acceleration of the own vehicle based at least on the driving condition, and performs acceleration assist (S570) to make the actual acceleration of the own vehicle consistent with the target acceleration.

[0006] Furthermore, the controller is configured to learn a steering preference level (S635) indicating the degree of the driver's preference for steering based on the steering operation performed by the driver of the own vehicle when the steering assist control is executed, and to determine the steering control amount based on the learned steering preference level, thereby changing the intensity of the steering assist. Figure 3), when configured to perform the acceleration assist control, based on the acceleration and deceleration operations performed by the driver of the own vehicle, an acceleration preference level indicating the degree of the driver's preference for acceleration is learned (S675), and the target acceleration is determined based on the learned acceleration preference level, thereby changing the intensity of the acceleration assist (S560).

[0007] Therefore, the driving assistance control device of the above aspect can automatically change the steering feel and / or acceleration feel in the driving assistance control according to the driver's preference.

[0008] In the above description, to facilitate understanding of the present invention, the names and / or reference numerals used in the embodiments described below are enclosed in parentheses to indicate the components of the invention corresponding to the embodiments described. However, the components of the present invention are not limited to the embodiments specified by these names and / or reference numerals. The present invention also relates to a driving assistance control method and program thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like reference numerals represent like elements, and wherein:

[0010] Figure 1 is a schematic diagram of the configuration of a driving assistance control device according to an embodiment of the present invention;

[0011] Figure 2A is a diagram showing parameters used in lane keeping control;

[0012] Figure 2B is a diagram showing a state of steering assist control in lane keeping control;

[0013] Figure 2C FIG. 1 is a diagram showing a situation of acceleration assist control in following vehicle distance control;

[0014] Figure 3 yes Figure 1 The routine executed by the CPU of the driving assistance ECU shown;

[0015] Figure 4 yes Figure 1 The routine executed by the CPU of the driving assistance ECU shown;

[0016] Figure 5 yes Figure 1 The routine executed by the CPU of the driving assistance ECU shown;

[0017] Figure 6 yes Figure 1 The routine shown is executed by the CPU of the driving assistance ECU. DETAILED DESCRIPTION

[0018] A "vehicle driving assistance control device DS (hereinafter referred to as 'device DS')" according to an embodiment of the present invention includes Figure 1 The components shown are applicable to a self-vehicle HV. The self-vehicle HV may be any of a vehicle using an internal combustion engine as a power source, a battery electric vehicle, and a hybrid electric vehicle.

[0019] In this specification, "ECU" refers to an electronic control unit including a microcomputer including a processor (CPU), ROM, RAM, and a non-volatile memory capable of writing data. ECU is also called a controller or a computer. Figure 1 The plurality of ECUs shown are connected via a Controller Area Network (CAN) so as to be able to exchange information with each other. Some or all of the plurality of ECUs may be integrated into one ECU.

[0020] The driving support ECU 10 (hereinafter referred to as "DSECU") is connected to Figure 1 The components shown above exchange signals with each other to execute lane keeping control (LTA) and following distance control (ACC).

[0021] The camera device 20 includes a camera 21 and an image ECU 22. The camera 21 obtains image data representing the image in front of the own vehicle HV at every predetermined time. The image ECU 22 recognizes the lane in which the own vehicle HV is traveling, i.e., the "left boundary line LL and right boundary line RL" of the own lane based on the image data. The image ECU 22 obtains the target driving line TL, the road curvature CL, the lateral deviation (skew, change) DL, and the yaw angle (heading angle) deviation θL based on the image data (see FIG. Figure 2A ), and generates camera target information. The camera target information includes the "position and type" of the target existing in front of the own vehicle HV.

[0022] The radar device 30 is a well-known device that uses radio waves in the millimeter wave band to obtain information about targets in front of the vehicle HV. It includes a radar 31 and a radar ECU 32. At predetermined intervals, the radar 31 transmits millimeter waves within a predetermined detection range and receives millimeter waves reflected by the target. The radar ECU 32 obtains radar target information based on the information about the millimeter waves transmitted and received by the radar 31. Radar target information includes the distance to the target, the target's direction, and the target's relative speed. In addition, the DSECU generates synthetic (fusion) target information by integrating camera target information and radar target information.

[0023] The powertrain ECU 40 drives the powertrain actuator 41 based on instructions from the DSECU or the driver's operation of the accelerator pedal. This adjusts the driving force generated by the driving device (internal combustion engine, electric motor, etc.) of the host vehicle HV and controls the acceleration of the host vehicle HV.

[0024] The brake ECU 50 drives the brake actuator 51 in response to an instruction from the DSECU or a driver's operation of the brake pedal, thereby adjusting the braking force generated by the brake device of the own vehicle HV and controlling the deceleration (negative acceleration) of the own vehicle HV.

[0025] The steering ECU 60 drives the steering motor 61 according to an instruction from the DSECU or a driver's steering wheel operation (steering operation), thereby controlling the steering device of the vehicle HV and changing the steering assist force and the steering angle (rudder angle) of the vehicle HV.

[0026] DSECU inputs the detection values or output values of the following "sensors and switches".

[0027] ■An accelerator pedal operation amount sensor 81 that detects the accelerator pedal operation amount AP of the own vehicle HV.

[0028] ■A brake pedal operation amount sensor 82 that detects the brake pedal operation amount BP of the own vehicle HV.

[0029] ■A vehicle speed sensor 83 that detects the speed of the own vehicle HV (ie, own vehicle speed Vh).

[0030] ■ A longitudinal acceleration sensor 84 that detects the longitudinal acceleration (fore-and-aft acceleration) Gx of the own vehicle HV.

[0031] ■ A lateral acceleration sensor 85 that detects the acceleration (lateral acceleration) Gy of the own vehicle HV in the vehicle width direction.

[0032] ■ A steering angle sensor 86 that detects a steering angle θ of a steering wheel of the own vehicle HV.

[0033] ■ An ACC switch 87 as an operation switch for turning ACC on and off (ON / OFF).

[0034] ■ LTA switch 88 as an operation switch for turning the LTA on and off.

[0035] Summary of the work

[0036] The device DS executes, as driving assist control, a lane keeping control which is one of the steering assist controls and a following vehicle distance control which is one of the acceleration assist controls.

[0037] The device DS changes the magnitude of the steering control amount during lane keeping control and the acceleration of the host vehicle HV during a specific condition during following distance control, based on the driver's preference. A specific condition refers to a situation where the host vehicle speed Vh has not increased to a predetermined target speed Vtgt after a transition from a state in which a preceding vehicle (following vehicle) to be followed exists and the distance between the host vehicle HV and the preceding vehicle is maintained at a target distance by following distance control to a state in which the preceding vehicle no longer exists. This failure to increase the host vehicle speed Vh to the predetermined target speed Vtgt indicates that a specific acceleration condition has been satisfied.

[0038] More specifically, the device DS learns (acquires) a "steering preference level" indicating the driver's steering preference based on the driver's actual steering operation. The device DS changes the steering control amount in lane keeping control and the intensity of steering assist according to the steering preference level.

[0039] For example, in the case where the learned turning preference level is weak, e.g. Figure 2B As shown in the left figure of FIG, the device DS makes the own vehicle HV slowly approach the target driving line TL during the execution of lane keeping control. Figure 2B As shown in the right figure of , the device DS makes the own vehicle HV quickly approach the target travel line TL during execution of the lane keeping control.

[0040] The device DS also learns an “acceleration preference level” indicating the driver’s acceleration preference based on the driver’s actual acceleration and deceleration operations. The device DS changes the target acceleration during the specific situation and the intensity of the acceleration assistance according to the learned acceleration preference level.

[0041] For example, in the case where the learned acceleration preference level is weak, e.g. Figure 2CAs shown in the left figure of , the device DS accelerates the own vehicle HV relatively slowly during the occurrence of the above-mentioned specific situation. Figure 2C As shown in the right figure of , the device DS accelerates the own vehicle HV relatively rapidly during the occurrence of the above-mentioned specific situation.

[0042] Specific work

[0043] The CPU of the DSECU executes the Figures 3 to 6 In the following, "step" is referred to as "S".

[0044] Gain setting for changing the intensity of steering assist

[0045] At a predetermined timing, the CPU Figure 3 After S300, the process proceeds to S310, where it is determined whether the value of the steering preference learning flag XSG is "1." This flag XSG is set to "1" when learning of the steering preference level is complete (see S640). Furthermore, the values of flag XSG and the acceleration preference learning flag XGG, described later, are set to "0" by an initialization routine (not shown) executed when the vehicle HV's starter switch is turned from the OFF position to the ON position. These flag values are stored in the DSECU's non-volatile memory.

[0046] If the value of the flag XSG is not "1", the CPU proceeds to S360 described later. On the other hand, if the value of the flag XSG is "1", the CPU proceeds from S310 to S320 to determine whether the Figure 6 Whether the steering preference level learned by the routine is "1" (strong).

[0047] When the steering preference level is "1" (strong), the CPU enters S330 from S320. The CPU sets the first gain K1 to "the product of the coefficient α1 and the positive value K1a", sets the second gain K2 to "the product of the coefficient α2 and the positive value K2a", and sets the third gain K3 to "the product of the coefficient α3 and the positive value K3a". The coefficients α1, α2, and α3 are each a constant greater than "1". Next, the CPU enters S340 and stores the values of the first to third gains (K1, K2, K3) used when calculating the target steering angle θtgt in the non-volatile memory of the DSECU. Then, the CPU enters S395 and temporarily ends this routine.

[0048] If the learned steering preference level is not "1" (strong), the CPU proceeds from S320 to S350, where it determines whether the learned steering preference level is "2" (medium). If the learned steering preference level is "2" (medium), the CPU proceeds from S350 to S360, where it sets the first gain K1 to K1a, the second gain K2 to K2a, and the third gain K3 to K3a. The CPU then proceeds to S340 and S395.

[0049] If the learned steering preference level is not "2" (medium), the CPU proceeds from S350 to S370, where it determines whether the learned steering preference level is "3" (weak). If the learned steering preference level is "3" (weak), the CPU proceeds from S370 to S380, where it sets the first gain K1 to the product of coefficient β1 and value K1a. The CPU sets the second gain K2 to the product of coefficient β2 and value K2a, and the third gain K3 to the product of coefficient β3 and value K3a. Coefficients β1, β2, and β3 are each constant values greater than 0 and less than 1. The CPU then proceeds to S340 and S395.

[0050] If the learned steering preference level is not "3" (weak), but "4" (very weak), the CPU proceeds from S370 to S390, where it sets the first gain K1 to the product of coefficient γ1 and value K1a, and the second gain K2 and the third gain K3 to "0." Coefficient γ1 is a constant value greater than "0" and smaller than coefficient β1. The CPU then proceeds to S340 and S395.

[0051] Lane Keeping Control

[0052] At a predetermined timing, the CPU Figure 4 The process of S400 proceeds to S410 to determine whether the execution condition of the lane keeping control is satisfied. For example, the execution condition of the lane keeping control is that the LTA switch 88 is operated to set the lane keeping control to on, and Figure 2A This is true when both the “left boundary line LL and the right boundary line RL” of the vehicle lane are recognized by the camera device 20 .

[0053] If the execution conditions for lane keeping control are not met, the CPU proceeds directly from S410 to S495 and temporarily terminates this routine. On the other hand, if the execution conditions for lane keeping control are met, the CPU executes the processes from S420 to S450 and proceeds to S495.

[0054] S420: The CPU reads the values of the first to third gains (K1, K2, K3) from the nonvolatile memory.

[0055] S430: The CPU obtains the target driving line TL, road curvature CL, lateral deviation DL and yaw angle deviation θL for lane keeping control from the image data (or the image ECU 22). Figure 2A As shown, the target travel line TL is the line connecting the center positions of the left and right boundary lines LL and RL in the lane width direction. The road curvature CL is the curvature of the target travel line TL (the inverse of the radius of the target travel line TL). The lateral deviation DL is the distance between the center position of the vehicle width direction of the host vehicle HV (for example, the center position of the left and right front wheels) and the target travel line TL. The yaw angle deviation θL is the angle between the tangent direction of the target travel line TL and the travel direction of the host vehicle HV.

[0056] S440: The CPU calculates the target steering angle θtgt as the steering control amount by substituting the values of the first to third gains (K1, K2, K3) and the road curvature CL, the lateral deviation DL, and the yaw angle deviation θL into the following equation (1).

[0057] θtgt=K1·CL+K2·DL+K3·θL…(1)

[0058] S450: The CPU instructs the steering ECU 60 to align the actual steering angle θact with the target steering angle θtgt. Based on the actual steering angle θact, the target steering angle θtgt, and the vehicle's own speed Vh, the steering ECU 60 calculates the target steering torque Tqtgt from a lookup table and instructs the steering motor 61 to generate a torque consistent with the target steering torque Tqtgt. As a result, the actual steering angle θact and the target steering angle θtgt are aligned, and the vehicle HV travels along the target travel line TL.

[0059] In this way, the first to third gains (K1, K2, K3) are modified according to the learned steering preference level. As a result, the steering control amount varies according to the learned steering preference level. Thus, the intensity of the steering assist varies according to the learned steering preference level, enabling lane keeping control, as a steering assist control, to be executed in accordance with the driver's preference.

[0060] Following vehicle distance control

[0061] At a predetermined timing, the CPU Figure 5 The process proceeds from S500 to S510 to determine whether the execution conditions for the following vehicle distance control are met. For example, the execution conditions for the following vehicle distance control are met when the own vehicle speed Vh is greater than or equal to the vehicle speed threshold Vth and the ACC switch 87 is operated to set the following vehicle distance control to on.

[0062] If the conditions for executing the following vehicle distance control are not met, the CPU proceeds directly from S510 to S595 and temporarily terminates this routine. In contrast, if the conditions for executing the following vehicle distance control are met, the CPU proceeds from S510 to S520, where it determines whether a preceding vehicle exists based on the synthesized target object information. A preceding vehicle is another vehicle traveling within its own lane, immediately ahead of its own vehicle HV, and within a predetermined distance from the own vehicle HV.

[0063] If there is a preceding vehicle, the CPU proceeds from S520 to S530, where it controls the acceleration of the host vehicle HV so that the inter-vehicle distance between the preceding vehicle and the host vehicle HV matches a predetermined target inter-vehicle distance. For details, see Japanese Patent Application Laid-Open Nos. 2020-26154, 2014-148293, and 4172434. The CPU then proceeds to S595, temporarily terminating this routine.

[0064] On the other hand, when there is no preceding vehicle, the CPU proceeds from S520 to S540 to determine whether the above-mentioned specific situation has occurred at the current time point.

[0065] When a specific situation occurs, the CPU proceeds from S540 to S550 to determine whether the value of the accelerated hobby learning flag XGG is "1". The value of the flag XGG is set to "1" when the learning of the accelerated hobby level is completed (see S680). When the value of the flag XGG is "1", the CPU proceeds from S550 to S560, based on the "passed" Figure 6 The target acceleration Gtgt is determined by the acceleration preference level learned by the routine.

[0066] More specifically, the DSECU stores a lookup table LT in its ROM (see S560). ROM is an example of a storage medium. The CPU determines the target acceleration Gtgt by applying the learned acceleration preference level to the lookup table LT. For example, when the acceleration preference level is "1" (strong), the acceleration Gx1 is obtained as the target acceleration Gtgt. When the learned acceleration preference level is "2" (medium), the acceleration Gx2 is obtained as the target acceleration Gtgt. When the learned acceleration preference level is "3" (weak), the acceleration Gx3 is obtained as the target acceleration Gtgt. When the learned acceleration preference level is "4" (extremely weak), the acceleration Gx4 is obtained as the target acceleration Gtgt. In addition, between these accelerations Gx1 to Gx4, the following formula (2) holds.

[0067] 0 <Gx4<Gx3<Gx2<Gx1…(2)

[0068] Next, the CPU proceeds to S570 and controls the acceleration of the own vehicle HV via the powertrain ECU 40 so that the actual acceleration Gx of the own vehicle HV matches the target acceleration Gtgt until the own vehicle speed Vh increases to the target vehicle speed Vtgt.

[0069] When the CPU enters S550 , if the value of the acceleration preference learning flag XGG is not “1” (is “0”), the CPU proceeds from S550 to S580 to set the target acceleration Gtgt to acceleration Gx2 .

[0070] As the process of S570 continues, the vehicle speed Vh gradually increases and reaches the target speed Vtgt. In this case, the CPU proceeds to S540, makes a "No" determination, and proceeds to S590. In S590, the CPU executes known constant speed control, which controls the acceleration of the vehicle HV so that the vehicle speed Vh matches the target speed Vtgt. The CPU then proceeds to S595.

[0071] In this way, the CPU sets the target acceleration Gtgt during the occurrence of the specific situation based on the learned acceleration preference level. Therefore, the intensity of the acceleration assist in the acceleration assist control included in the following vehicle distance control is changed based on the learned acceleration preference level.

[0072] Shifting to hobby-level learning

[0073] At a predetermined timing, the CPU Figure 6 The process proceeds to S605 after S600 to determine whether the learning condition for the steering preference level is satisfied. The learning condition for the steering preference level is satisfied when lane keeping control is not currently being executed (in the lane keeping control non-execution period) and the value of the steering preference learning flag XSG is "0".

[0074] If the learning conditions for the steering preference level are met, the CPU proceeds from S605 to S610, where it determines whether the conditions for obtaining the actual steering maximum value θactmax are met. The actual steering maximum value θactmax is the maximum value (maximum value) of the actual steering angle θact (|θact|). The conditions for obtaining the actual steering maximum value θactmax are met when a driving situation occurs in which the target steering angle θtgt (|θtgt|) reaches the "reference steering maximum value θtgtmax, which serves as its maximum value." The target steering angle θtgt is calculated based on the aforementioned equation (1), assuming that lane keeping control is being executed, with the first gain K1 set to value K1a, the second gain K2 set to value K2a, and the third gain K3 set to value K3a.

[0075] When the conditions for obtaining the actual steering maximum value θactmax are satisfied, the CPU performs the following “processing of S615 to S625 ” and proceeds to S630 .

[0076] S615: The CPU obtains the actual steering maximum value θactmax and the reference steering maximum value θtgtmax. The actual steering maximum value θactmax is a value between a first time point a predetermined time before the time (maximum time) when the calculated target steering angle θtgt reaches the reference steering maximum value θtgtmax, and a second time point a predetermined time after the maximum time point.

[0077] S620: The CPU updates the score P by adding a value determined based on the actual steering maximum value θactmax, the reference steering maximum value θtgtmax, and the function f (=f(θactmax, θtgtmax)) to the score P at that point in time.

[0078] The function f is as follows: R is a positive predetermined value.

[0079] When θtgtmax+2·R≤θactmax: f(θactmax,θtgtmax)=+2

[0080] When θtgtmax+R≤θactmax<θtgtmax+2·R: f(θactmax,θtgtmax)=+1

[0081] When θtgtmax-R≤θactmax<θtgtmax+R: f(θactmax,θtgtmax)=0

[0082] When θtgtmax-2·R≤θactmax<θtgtmax-R: f(θactmax,θtgtmax)=-1

[0083] When θactmax<θtgtmax-2·R: f(θactmax,θtgtmax)=-2

[0084] S625: The CPU increases the number of steering samples nLTA by “1.” Note that the score P and the number of steering samples nLTA are set to “0” when the vehicle HV is shipped and are stored in the nonvolatile memory of the DSECU.

[0085] Next, the CPU proceeds to S630 to determine whether the number of steering samples nLTA is greater than a predetermined threshold value nth. If the number of steering samples nLTA is greater than the threshold value nth, the CPU proceeds from S630 to S635 to determine the steering preference level based on the average value PAV (=P / nth) of the scores P, for example, as follows.

[0086] 1.5 ≤ Average PAV: Steering preference level = 1 (strong)

[0087] -0.2≤Average PAV<1.5: Steering preference level = 2 (medium)

[0088] -0.8≤Average PAV<-0.2: Steering preference level = 3 (weak)

[0089] When the average PAV is less than -0.8: Steering preference level = 4 (very weak)

[0090] That is, the larger the average value PAV is, the stronger the steering preference level is (closer to "1").

[0091] Next, the CPU proceeds to S640 and sets the value of the preference learning flag XSG to "1." The CPU then proceeds to S645. If the CPU determines "No" in any of S605, S610, and S630, it proceeds directly to S645 from the step in which the determination was "No."

[0092] Accelerated learning at the hobby level

[0093] The CPU determines in S645 whether the acceleration preference level learning condition is satisfied. The acceleration preference level learning condition is satisfied when the following vehicle distance control is not currently being executed (the following vehicle distance control is not being executed) and the value of the acceleration preference learning flag XGG is "0".

[0094] If the learning conditions for the acceleration preference level are met, the CPU proceeds from S645 to S650 to determine whether the conditions for obtaining the actual maximum acceleration value Gxmax are met. The actual maximum acceleration value Gxmax is the maximum value of the actual longitudinal acceleration Gx. The conditions for obtaining the actual maximum acceleration value Gxmax are met when the vehicle's speed Vh is within a predetermined range, the distance between the preceding vehicle immediately preceding the vehicle HV and the preceding vehicle HV is within a predetermined range, and the preceding vehicle no longer exists after the preceding vehicle HV has been present for a period exceeding a first threshold value.

[0095] When the conditions for obtaining the actual acceleration maximum value Gxmax are met, the CPU performs the "processing of S655 to S665" described below and proceeds to S670.

[0096] S655: The CPU obtains the maximum value (the largest value) of the actual acceleration Gx during the period from the time point when the acquisition condition for the previously mentioned maximum actual acceleration Gxmax is satisfied to the time point after a predetermined time as the actual acceleration maximum value Gxmax.

[0097] S660: The CPU updates the score Q by adding the value determined based on the actual acceleration maximum value Gxmax and the function g (=g(Gxmax)) to the score Q at this time point.

[0098] The function g is as follows. G0 is a positive reference acceleration, and T is a positive predetermined value.

[0099] When G0 + 2·T ≤ Gxmax: g(Gxmax) = +2

[0100] When G0 + T ≤ Gxmax < G0 + 2·T: g(Gxmax) = +1

[0101] When G0 - T ≤ Gxmax < G0 + T: g(Gxmax) = 0

[0102] When G0 - 2·T ≤ Gxmax < G0 - T: g(Gxmax) = -1

[0103] When Gxmax < -2·T: g(Gxmax) = -2

[0104] S665: The CPU increases the acceleration sample number nACC by "1".

[0105] Next, the CPU enters S670 and determines whether the acceleration sample number nACC is above the threshold nth. In addition, the score Q and the acceleration sample number nACC are set to "0" at the time of the factory shipment of the host vehicle HV and stored in the non-volatile memory of the DSECU. The non-volatile memory is an example of a storage medium. When the acceleration sample number nACC is above the threshold nth, the CPU enters S675 from S670 and determines the acceleration preference level based on the average value QAV of the score Q (=Q / nth), for example, as follows.

[0106] [[ID=三十一]]When 1.5 ≤ average value QAV: acceleration preference level = 1 (strong) ..

[0107] When -0.2 ≤ average value QAV < 1.5: acceleration preference level = 2 (medium)

[0108] When -0.8 ≤ average value QAV < -0.2: acceleration preference level = 3 (weak)

[0109] When average value QAV < -0.8: acceleration preference level = 4 (extremely weak)

[0110] That is, the larger the average value QAV is, the stronger the acceleration preference level is (closer to "1").

[0111] Next, the CPU proceeds to S680 and sets the value of the accelerated hobby learning flag XGG to "1." The CPU then proceeds to S695 and temporarily terminates this routine. If the CPU determines "No" in any of S645, S650, or S670, it proceeds to S695 from the step where the "No" determination was made.

[0112] As described above, the device DS can automatically change the intensity of the steering assist in the steering assist control according to the learned driver's steering preference level. In addition, the device DS can automatically change the intensity of the acceleration assist in the acceleration assist control according to the learned driver's acceleration preference level.

[0113] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention. For example, the present invention can also be applied to a vehicle in automatic driving or a vehicle in a state where the driving mode has changed from automatic driving to manual driving by the driver.

[0114] Furthermore, the present invention is also applicable to "lane departure prevention control or lane change assist control" as a steering assist control, and to scenarios where acceleration is being performed during normal constant speed driving control as an acceleration assist control. Acceleration during normal constant speed driving control as an acceleration assist control is, for example, performed during the resumption of constant speed driving control after cancellation (i.e., when resuming constant speed driving control). Furthermore, the device DS may be configured to change only one of the "steering assist intensity and acceleration assist intensity" according to each corresponding preference level.

[0115] The steering preference level can also be learned based on the "lane width direction position, movement amount, movement speed, lateral acceleration Gy, and yaw rate of the own vehicle HV" relative to the shape (curvature) of the own lane during periods when lane keeping control is not being executed and the driver is manually driving. Furthermore, the steering preference level can also be learned based on the frequency of driver intervention in steering operations during periods when lane keeping control is being executed.

[0116] The acceleration preference level can also be learned based on information such as the accelerator pedal operation amount, brake pedal operation amount, and the distance to the preceding vehicle during periods when following distance control is not in effect and the driver is manually driving. Furthermore, the acceleration preference level can also be learned based on information such as the frequency of acceleration intervention and the frequency of brake intervention during deceleration during periods when following distance control is in effect.

[0117] Furthermore, the device DS may determine an upper limit (permissible) lateral acceleration Gymax in the steering assist control based on the steering preference level (see the parentheses in S330, S360, S380, and S390), and determine the steering control amount of the steering assist control so that the actual lateral acceleration during the steering assist does not exceed the upper limit lateral acceleration. Furthermore, the device DS may determine an upper limit (permissible) yaw rate in the steering assist control based on the steering preference level, and determine the steering control amount of the steering assist control so that the actual yaw rate during the steering assist does not exceed the upper limit yaw rate.

Claims

1. A driving assistance control device for a vehicle, A controller is provided for executing at least one of a steering assist control and an acceleration assist control as a driving assist control, The steering assist control determines a steering control amount for automatically changing an actual steering angle of the own vehicle based on at least a driving condition of the own vehicle, and performs steering assist for changing the actual steering angle based on the steering control amount. The acceleration assist control determines a target acceleration for automatically changing the actual acceleration of the own vehicle based on at least the driving condition, and performs acceleration assist for controlling the actual acceleration so that the actual acceleration of the own vehicle matches the target acceleration. The controller is configured as follows: In a configuration in which the steering assist control is executed, a steering preference level indicating the degree of the driver's preference regarding steering is learned based on a steering operation performed by the driver of the own vehicle, and the steering control amount is determined based on the learned steering preference level, thereby changing the intensity of the steering assist. When the acceleration assist control is configured to be executed, an acceleration preference level indicating the degree of the driver's preference for acceleration is learned based on acceleration and deceleration operations performed by the driver of the own vehicle, and the target acceleration is determined based on the learned acceleration preference level, thereby changing the intensity of the acceleration assist.

2. The driving assistance control device for a vehicle according to claim 1, The controller is configured to execute lane keeping control as the steering assist control, wherein the lane keeping control changes the steering control amount so that the own vehicle travels along a predetermined target travel line set in a lane in which the own vehicle travels. The controller is further configured to: Obtaining the curvature of the target driving line, namely the road curvature (CL), the distance between the target driving line and the own vehicle in the lane width direction, namely the lateral deviation (DL), and the angle between the tangent direction of the target driving line and the traveling direction of the own vehicle, namely the yaw angle deviation (θL), The steering control amount in the lane keeping control is calculated based on a first term (K1·CL) which is the product of the road curvature (CL) and a first gain (K1), a second term (K2·DL) which is the product of the lateral deviation (DL) and a second gain (K2), and a third term (K3·θL) which is the product of the yaw angle deviation (θL) and a third gain (K3), The intensity of the steering assist is changed by changing the first gain, the second gain, and the third gain according to the steering preference level.

3. The driving assistance control device for a vehicle according to claim 1, The controller is configured to, as the acceleration assist control, cause the own vehicle to follow the leading vehicle traveling immediately in front of the own vehicle in such a manner that a predetermined inter-vehicle distance is maintained between the own vehicle and the leading vehicle, and, when the leading vehicle no longer exists in the state in which the own vehicle is caused to follow the leading vehicle, perform the acceleration assist until the speed of the own vehicle reaches a predetermined target vehicle speed.

4. A driving assistance control method for a vehicle, comprising: executing at least one of steering assistance control and acceleration assistance control as driving assistance control, wherein the steering assistance control determines a steering control amount for automatically changing an actual steering angle of the own vehicle based at least on a driving condition of the own vehicle, and performs steering assistance for changing the actual steering angle based on the steering control amount; and the acceleration assistance control determines a target acceleration for automatically changing an actual acceleration of the own vehicle based at least on the driving condition, and performs acceleration assistance for controlling the actual acceleration so that the actual acceleration of the own vehicle matches the target acceleration. The driving assistance control method comprises the following steps: When the steering assist control is executed, a steering preference level indicating the degree of the driver's preference for steering is learned based on the steering operation performed by the driver of the own vehicle, and the steering control amount is determined based on the learned steering preference level, thereby changing the intensity of the steering assist. When the acceleration assist control is executed, an acceleration preference level indicating the degree of the driver's acceleration preference is learned based on acceleration and deceleration operations performed by the driver of the own vehicle, and the target acceleration is determined based on the learned acceleration preference level, thereby changing the intensity of the acceleration assist.

5. A program that is executed by a computer installed in a vehicle. The program includes a step of causing the computer to execute at least one of steering assist control and acceleration assist control as driving assist control, wherein the steering assist control determines a steering control amount for automatically changing an actual steering angle of the own vehicle based on at least a driving condition of the own vehicle, and performs steering assistance for changing the actual steering angle based on the steering control amount, and the acceleration assist control determines a target acceleration for automatically changing an actual acceleration of the own vehicle based on at least the driving condition, and performs acceleration assistance for controlling the actual acceleration so that the actual acceleration of the own vehicle matches the target acceleration. The program further causes the computer to execute the following steps: When the steering assist control is executed, a steering preference level indicating the degree of the driver's preference for steering is learned based on the steering operation performed by the driver of the own vehicle, and the steering control amount is determined based on the learned steering preference level, thereby changing the intensity of the steering assist. When the acceleration assist control is executed, an acceleration preference level indicating the degree of the driver's acceleration preference is learned based on acceleration and deceleration operations performed by the driver of the own vehicle, and the target acceleration is determined based on the learned acceleration preference level, thereby changing the intensity of the acceleration assist.

Images