Patent Publication Number: US-2023142656-A1

Title: Vehicle control system, vehicle control method, and storage medium

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Priority is claimed on Japanese Patent Application No. 2021-184167, filed Nov. 11, 2021, the content of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a vehicle control system, a vehicle control method, and a storage medium. 
     Description of Related Art 
     In the related art, for example, technology related to a vehicle control system in which a display unit is attached to an operation element such as a steering wheel and a current traveling situation in which the vehicle is traveling is presented to a driver who is an occupant has been disclosed (for example, Japanese Unexamined Patent Application, First Publication No. 2021-046042). In the related art, a vehicle speed meter indicating a traveling speed of a host vehicle is not displayed on a display unit when the vehicle is traveling in a driving mode of automated driving and the vehicle speed meter is displayed on the display unit when the vehicle is traveling in a driving mode of manual driving. 
     However, in the related art, the driver can easily confirm the current traveling speed of the host vehicle when the vehicle is allowed to travel in manual driving, but there is no display process of determining a sense of purpose such as a driver&#39;s desire to actively perform a vehicle driving operation and informing or reminding the driver of the determined sense of purpose. 
     SUMMARY OF THE INVENTION 
     The present invention has been made on the basis of the recognition of the above problems and an objective of the present invention is to provide a vehicle control system, a vehicle control method, and a storage medium capable of determining a driver&#39;s sense of purpose for driving and presenting a determination result to the driver. 
     A vehicle control system, a vehicle control method, and a storage medium according to the present invention adopt the following configurations. 
     (1): According to an aspect of the present invention, there is provided a vehicle control system including: a steering operation element configured to receive a steering operation of a vehicle by a driver; a grip detector configured to detect a gripping state of the steering operation element by the driver of the vehicle; and a display processor configured to cause a display device to display a notification image indicating at least the gripping state, wherein the notification image includes a first graphic deformable based on a circle within an entire image area, and wherein the display processor causes the display device to display the notification image including the first graphic deformed to expand a location corresponding to a part where the driver is gripping the steering operation element. 
     (2): In the above-described aspect (1), the grip detector detects the gripping state for each of a plurality of parts into which the steering operation element is divided and the display processor increases the diameter of the circle in the first graphic as the number of parts in which the steering operation element is detected to be gripped increases 
     (3): In the above-described aspect (2), the grip detector detects the gripping state in each of a first gripping part in an upper region of the steering operation element, a second gripping part in a right region of the steering operation element, a third gripping part in a lower region of the steering operation element, and a fourth gripping part in a left region of the steering operation element and the display processor changes the diameter of the circle in the first graphic based on a gripping position of the steering operation element and the number of grips of the driver. 
     (4): In the above-described aspect (3), if the number of grips is 2, the display processor changes the diameter of the circle in the first graphic to a longest first length when the gripping position corresponds to the second gripping part and the fourth gripping part and changes the diameter of the circle in the first graphic to a second length shorter than the first length when the gripping position corresponds to the first gripping part and/or the third gripping part, if the number of grips is 1, the display processor changes the diameter of the circle in the first graphic to a third length shorter than the second length when the gripping position corresponds to the second gripping part or the fourth gripping part and changes the diameter of the circle in the first graphic to a fourth length shorter than the third length when the gripping position corresponds to the first gripping part or the third gripping part, and if the number of grips is 0, the display processor changes the diameter of the circle in the first graphic to a fifth length shorter than the fourth length. 
     (5): In the above-described aspect (1), the display processor changes colors of the entire image area and/or the first graphic in accordance with the gripping state. 
     (6): In the above-described aspect (1), the vehicle control system further includes a traveling controller configured to perform traveling control related to steering and acceleration or deceleration of the vehicle determined based on the gripping state, wherein the notification image further includes a circular second graphic which is located outside of the first graphic in a radial direction of the circle and in which at least lengths of diameters of inner and outer circles and degrees of definition of the inner and outer circles can be changed, and wherein the display processor causes the display device to display the notification image including the first graphic and the second graphic obtained by changing any one of the length of the diameter of the inner circle, the length of the diameter of the outer circle, and the degrees of definition in accordance with a state of the determined traveling control. 
     (7): In the above-described aspect (6), the second graphic is divided into at least a right area and a left area, the traveling controller causes the steering operation element to generate a reaction force such that a traveling direction of the vehicle becomes a straight direction when the steering operation element has been operated in a direction outside of the straight direction by the driver using the straight direction of the vehicle as a reference, and the display processor highlights one of the right area and the left area corresponding to a direction in which the traveling controller causes the reaction force to be generated. 
     (8): In the above-described aspect (7), the traveling controller causes the reaction force generated by the steering operation element to stop when a driver&#39;s operation on the steering operation element in the direction outside of the straight direction has continued and the display processor causes a color of an image area on a side of the highlighted area within the entire image area of the notification image to be changed to a color different from that of another image area. 
     (9): According to an aspect of the present invention, there is provided a vehicle control method including: receiving, by a computer mounted in a vehicle, a steering operation on a steering operation element of the vehicle by a driver; detecting, by the computer, a gripping state of the steering operation element by the driver of the vehicle; and when a display device is allowed to display a notification image indicating at least the gripping state and including a first graphic deformable based on a circle within an entire image area, causing, by the computer, the display device to display the notification image including the first graphic deformed to expand a location corresponding to a part where the driver is gripping the steering operation element. 
     (10): According to an aspect of the present invention, there is provided a non-transitory computer-readable storage medium storing a program for causing a computer mounted in a vehicle to: receive a steering operation on a steering operation element of the vehicle by a driver; detect a gripping state of the steering operation element by the driver of the vehicle; and when a display device is allowed to display a notification image indicating at least the gripping state and including a first graphic deformable based on a circle within an entire image area, cause the display device to display the notification image including the first graphic deformed to expand a location corresponding to a part where the driver is gripping the steering operation element. 
     According to the above-described aspects (1) to (10), it is possible to determine a driver&#39;s sense of purpose for driving and present a determination result to the driver. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a configuration diagram of a vehicle system using a vehicle control device according to an embodiment. 
         FIG.  2    is a functional configuration diagram of the vehicle control device. 
         FIG.  3    is a diagram showing an example of a notification image. 
         FIG.  4    is a diagram showing an example of corresponding relationships between driving modes, driving assistance, and traveling modes. 
         FIG.  5    is a diagram showing an example of a configuration in which a gripping state of a steering wheel is recognized from a driver. 
         FIG.  6    is a diagram showing an example of determination patterns for determining a driver&#39;s motivation. 
         FIG.  7    is a diagram showing an example of a notification image corresponding to a driver&#39;s motivation. 
         FIG.  8    is a diagram showing an example of degrees of execution of driving assistance and notification images corresponding to driver&#39;s motivations. 
         FIG.  9    is a flowchart showing an example of a flow of a process of determining the driver&#39;s motivation executed by a driving control determiner. 
         FIG.  10    is an example showing an example of a notification image when a notification of a change in a traveling state of a vehicle is provided. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Embodiments of a vehicle control system, a vehicle control method, and a storage medium of the present invention will be described below with reference to the drawings. As used throughout this disclosure, the singular forms “a,” “an,” and “the” include a plurality of references unless the context clearly dictates otherwise. 
     [Overall Configuration] 
       FIG.  1    is a configuration diagram of a vehicle system  1  using the vehicle control system according to an embodiment. A vehicle in which the vehicle system  1  is mounted is, for example, a vehicle such as a two-wheeled vehicle, a three-wheeled vehicle, or a four-wheeled vehicle, and a drive source thereof is an internal combustion engine such as a diesel engine or a gasoline engine, an electric motor, or a combination thereof. The electric motor operates using electric power generated by a power generator connected to the internal combustion engine or electric power when a secondary battery or a fuel cell is discharged. 
     For example, the vehicle system  1  includes a camera  10 , a radar device  12 , a light detection and ranging (LIDAR) sensor  14 , a physical object recognition device  16 , a communication device  20 , a human machine interface (HMI)  30 , a vehicle sensor  40 , a navigation device  50 , a map positioning unit (MPU)  60 , a driver monitor camera  70 , driving operation elements  80 , a vehicle control device  100 , a travel driving force output device  200 , a brake device  210 , and a steering device  220 . Such devices and equipment are connected to each other by a multiplex communication line such as a controller area network (CAN) communication line, a serial communication line, or a wireless communication network. The configuration shown in  FIG.  1    is merely an example and some of the components may be omitted or other components may be further added. 
     For example, the camera  10  is a digital camera using a solid-state imaging element such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS). The camera  10  is attached to any location on the vehicle (hereinafter referred to as a host vehicle M) in which the vehicle system  1  is mounted. When the view in front of the host vehicle M is imaged, the camera  10  is attached to an upper part of a front windshield, a rear surface of a rearview mirror, or the like. For example, the camera  10  periodically and iteratively images the surroundings of the host vehicle M. The camera  10  may be a stereo camera. 
     The radar device  12  radiates radio waves such as millimeter waves around the host vehicle M and detects at least the position (the distance to and the direction) of a physical object by detecting radio waves (reflected waves) reflected by the physical object. The radar device  12  is attached to any location on the host vehicle M. The radar device  12  may detect the position and the speed of the physical object in a frequency modulated continuous wave (FM-CW) scheme. 
     The LIDAR sensor  14  radiates light (or electromagnetic waves having a wavelength close to light) to the vicinity of the host vehicle M and measures scattered light. The LIDAR sensor  14  detects a distance to an object on the basis of time from light emission to light reception. The radiated light is, for example, pulsed laser light. The LIDAR sensor  14  is attached to any location on the host vehicle M. 
     The physical object recognition device  16  performs a sensor fusion process on detection results from some or all of the camera  10 , the radar device  12 , and the LIDAR sensor  14  to recognize the position, a type, the speed, and the like of a physical object. The physical object recognition device  16  outputs recognition results to the vehicle control device  100 . The physical object recognition device  16  may output detection results of the camera  10 , the radar device  12 , and the LIDAR sensor  14  to the vehicle control device  100  as they are. The physical object recognition device  16  may be omitted from the vehicle system  1 . 
     The communication device  20  communicates with another vehicle located in the vicinity of the host vehicle M, or communicates with various types of server devices via a radio base station, using, for example, a cellular network or a Wi-Fi network, Bluetooth (registered trademark), dedicated short range communication (DSRC), or the like. 
     The HMI  30  presents various types of information to an occupant of the host vehicle M and receives an input operation by the occupant. The HMI  30  includes various types of display devices, a speaker, a buzzer, a touch panel, a switch, keys, and the like. In  FIG.  1   , a display device  32  provided in the HMI  30  is shown. The display device  32  is provided, for example, in the central portion of an instrument panel of the host vehicle M, and is a so-called information display that is a display device for displaying various types of information in the host vehicle M such as a speedometer indicating the traveling speed of the host vehicle M or a tachometer indicating the number of revolutions (a rotational speed) of the internal combustion engine provided in the host vehicle M. 
     The vehicle sensor  40  includes a vehicle speed sensor configured to detect the speed of the host vehicle M, an acceleration sensor configured to detect acceleration, a yaw rate sensor configured to detect angular velocity around a vertical axis, a direction sensor configured to detect a direction of the host vehicle M, and the like. 
     For example, the navigation device  50  includes a global navigation satellite system (GNSS) receiver  51 , a navigation HMI  52 , and a route determiner  53 . The navigation device  50  stores first map information  54  in a storage device such as a hard disk drive (HDD) or a flash memory. The GNSS receiver  51  identifies the position of the host vehicle M based on a signal received from a GNSS satellite. The position of the host vehicle M may be identified or corrected by an inertial navigation system (INS) using an output of the vehicle sensor  40 . The navigation HMI  52  includes a display device, a speaker, a touch panel, keys, and the like. The navigation HMI  52  may be partly or wholly shared with the above-described HMI  30 . For example, the route determiner  53  determines on a route (hereinafter referred to as a route on a map) from the position of the host vehicle M identified by the GNSS receiver  51  (or any input position) to a destination input by the occupant using the navigation HMI  52  with reference to the first map information  54 . The first map information  54  is, for example, information in which a road shape is expressed by a link indicating a road and nodes connected by the link. The first map information  54  may include the curvature of a road, point of interest (POI) information, and the like. The route on the map is output to the MPU  60 . The navigation device  50  may perform route guidance using the navigation HMI  52  on the basis of the route on the map. The navigation device  50  may be implemented, for example, according to a function of a terminal device such as a smartphone or a tablet terminal possessed by the occupant. The navigation device  50  may transmit a current position and a destination to a navigation server via the communication device  20  and acquire a route equivalent to the route on the map from the navigation server. 
     For example, the MPU  60  includes a recommended lane determiner  61  and stores second map information  62  in a storage device such as an HDD or a flash memory. The recommended lane determiner  61  divides the route on the map provided from the navigation device  50  into a plurality of blocks (for example, divides the route every 100 [m] in a traveling direction of the vehicle), and determines on a recommended lane for each block with reference to the second map information  62 . The recommended lane determiner  61  determines in what lane numbered from the left the vehicle will travel. The recommended lane determiner  61  determines on the recommended lane such that the host vehicle M can travel along a reasonable route for traveling to a branching destination when there is a branch point in the route on the map. 
     The second map information  62  is map information having higher accuracy than the first map information  54 . For example, the second map information  62  includes information about a center of a lane, information about a boundary of a lane, and the like. The second map information  62  may include road information, traffic regulations information, address information (an address/postal code), facility information, telephone number information, information about a prohibition section where mode A or mode B is prohibited to be described below, and the like. The second map information  62  may be updated at any time when the communication device  20  communicates with another device. 
     The driver monitor camera  70  is, for example, a digital camera that uses a solid-state image sensor such as a CCD or a CMOS. The driver monitor camera  70  is attached to any location on the host vehicle M with respect to the position and a direction where the head of the occupant (hereinafter, the driver) sitting in the driver&#39;s seat of the host vehicle M can be imaged from the front (in a direction in which his/her face is imaged). For example, the driver monitor camera  70  is attached to an upper part of a display device provided on the central portion of the instrument panel of the host vehicle M. The driver monitor camera  70  outputs an image obtained by imaging the cabin including the driver of the host vehicle M captured from the position where the driver monitor camera  70  is disposed to the vehicle control device  100 . 
     For example, the driving operation elements  80  include an accelerator pedal, a brake pedal, a shift lever, and other operation elements in addition to a steering wheel  82 . A sensor configured to detect an amount of operation or the presence or absence of an operation is attached to the driving operation element  80  and a detection result thereof is output to the vehicle control device  100  or some or all of the travel driving force output device  200 , the brake device  210 , and the steering device  220 . The steering wheel  82  does not necessarily have to be annular and may be in the form of a variant steering wheel, a joystick, a button, or the like. A steering grip sensor  84  is attached to the steering wheel  82 . The steering grip sensor  84  is implemented by a capacitance sensor, a voltage sensor, or the like and outputs a signal for detecting whether or not the driver is gripping the steering wheel  82  (indicating that the driver is in contact with the steering wheel  82  in a state in which a force is applied) to the vehicle control device  100 . The steering wheel  82  is an example of a “steering operation element” and the steering grip sensor  84  is an example of a “grip detector.” 
     The vehicle control device  100  includes, for example, an automated driving controller  120 , a driving assistance controller  140 , a traveling mode controller  160 , a driving control determiner  180 , and a display processor  190 . Each of the automated driving controller  120 , the driving assistance controller  140 , the traveling mode controller  160 , the driving control determiner  180 , and the display processor  190  is implemented, for example, by a hardware processor such as a central processing unit (CPU) executing a program (software). Some or all of these components may be implemented by hardware (including a circuit; circuitry) such as a large-scale integration (LSI) circuit, an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a graphics processing unit (GPU) or may be implemented by software and hardware in cooperation. The program may be pre-stored in a storage device (a storage device including a non-transitory storage medium) such as an HDD or a flash memory of the vehicle control device  100  or may be stored in a removable storage medium such as a DVD or a CD-ROM and installed in the HDD or the flash memory of the vehicle control device  100  when the storage medium (the non-transitory storage medium) is mounted in a drive device. 
       FIG.  2    is a functional configuration diagram of the vehicle control device  100 . The automated driving controller  120  includes, for example, a first recognizer  122 , the action plan generator  124 , and an electronic control unit (ECU) controller  126 . The driving assistance controller  140  includes, for example, a second recognizer  142  and a driving assistance executor  144 . The display processor  190  includes, for example, a notification image generator  192 . For example, the automated driving controller  120  and the driving assistance controller  140  implement a function based on artificial intelligence (AI) and a function based on a previously given model in parallel. For example, an “intersection recognition” function in the automated driving controller  120  may be implemented by executing intersection recognition based on deep learning or the like and recognition based on previously given conditions (signals, road markings, or the like, with which pattern matching is possible) in parallel and performing comprehensive evaluation by assigning scores to both recognitions. Thereby, the reliability of automated driving is secured. For example, the function of “recognizing the driver&#39;s motivation and sense of purpose (i.e., the driver&#39;s motivation for driving) to drive the host vehicle M” in the driving control determiner  180  may also be similarly implemented by recognizing the driver&#39;s face (facial expression) through deep learning, pattern matching, or the like. 
     The first recognizer  122  recognizes states of positions, speeds, acceleration, and the like of physical objects near the host vehicle M on the basis of information input from the camera  10 , the radar device  12 , and the LIDAR sensor  14  via the physical object recognition device  16 . For example, the position of the physical object is recognized as the absolute coordinates of a representative point (the center of gravity, the driving shaft center, or the like) of the host vehicle M as the origin and is used for control. The position of the physical object may be represented by a representative point such as the center of gravity or a corner of the physical object or may be represented by a represented area. The “state” of a physical object may include acceleration or jerk of the physical object or an “action state” (for example, whether or not a lane change is being made or intended). 
     For example, the first recognizer  122  recognizes a lane in which the host vehicle M is traveling (a traveling lane). For example, the first recognizer  122  recognizes the traveling lane by comparing a pattern of a road marking (for example, an arrangement of solid lines and broken lines) obtained from the second map information  62  with a pattern of road markings in the vicinity of the host vehicle M recognized from an image captured by the camera  10 . The first recognizer  122  may recognize a traveling lane by recognizing a traveling path boundary (a road boundary) including a road marking, a road shoulder, a curb, a median strip, a guardrail, or the like as well as a road marking. In this recognition, the position of the host vehicle M acquired from the navigation device  50  or a processing result of the INS may be added. Also, the first recognizer  122  recognizes a temporary stop line, an obstacle, a red traffic light, a toll gate, and other road events. 
     When the traveling lane is recognized, the first recognizer  122  recognizes the position or orientation of the host vehicle M with respect to the traveling lane. For example, the first recognizer  122  may recognize a gap of a reference point of the host vehicle M from the center of the lane and an angle formed with respect to a line connected to the center of the lane in the traveling direction of the host vehicle M as a relative position and orientation of the host vehicle M related to the traveling lane. Alternatively, the first recognizer  122  may recognize the position of the reference point of the host vehicle M related to one side end portion (a road marking or a road boundary) of the traveling lane or the like as a relative position of the host vehicle M related to the traveling lane. 
     The action plan generator  124  generates a future target trajectory along which the host vehicle M automatically travels (independently of the driver&#39;s operation) such that the host vehicle M can generally travel in the recommended lane determined on by the recommended lane determiner  61  and further cope with a surrounding situation of the host vehicle M. For example, the target trajectory includes a speed element. For example, the target trajectory is represented by sequentially arranging points (trajectory points) at which the host vehicle M is required to arrive. The trajectory points are points at which the host vehicle M is required to arrive for each prescribed traveling distance (for example, about several meters [m]) along a road. In addition, a target speed and target acceleration for each prescribed sampling time (for example, about several tenths of a second [sec]) are generated as parts of the target trajectory. The trajectory point may be a position at which the host vehicle M is required to arrive at the sampling time for each prescribed sampling time. In this case, information about the target speed or the target acceleration is represented by an interval between the trajectory points. 
     The action plan generator  124  may set an automated driving event when a target trajectory is generated. Automated driving events include a constant-speed traveling event, a low-speed tracking traveling event, a lane change event, a branch point-related movement event, a merging point-related movement event, a takeover event, and the like. The action plan generator  124  generates a target trajectory according to an activated event. 
     The ECU controller  126  controls the travel driving force output device  200 , the brake device  210 , and the steering device  220  such that the host vehicle M passes along the target trajectory generated by the action plan generator  124  at the scheduled times. 
     The ECU controller  126  includes, for example, a speed control function and a steering control function. The ECU controller  126  acquires information about a target trajectory (trajectory points) generated by the action plan generator  124  and causes a memory (not shown) to store the information. The ECU controller  126  controls the travel driving force output device  200  or the brake device  210  on the basis of a speed element associated with the target trajectory stored in the memory. The ECU controller  126  controls the steering device  220  in accordance with the degree of curvature of the target trajectory stored in the memory. A process of controlling a speed control function and a steering control function in the ECU controller  126  is implemented by, for example, a combination of feedforward control and feedback control. As an example, the steering control function is executed in a combination of feedforward control according to the curvature of the road in front of the host vehicle M and feedback control based on deviation from the target trajectory. Control of a steering control function of the ECU controller  126  is an example of “traveling control.” 
     The travel driving force output device  200  outputs a travel driving force (torque) for enabling the vehicle to travel to the driving wheels. For example, the travel driving force output device  200  includes a combination of an internal combustion engine, an electric motor, a transmission, and the like, and an ECU that controls the internal combustion engine, the electric motor, the transmission, and the like. The ECU controls the above-described components in accordance with information input from the ECU controller  126  or information input from the driving operation element  80 . 
     For example, the brake device  210  includes a brake caliper, a cylinder configured to transfer hydraulic pressure to the brake caliper, an electric motor configured to generate hydraulic pressure in the cylinder, and a brake ECU. The brake ECU controls the electric motor in accordance with the information input from the ECU controller  126  or the information input from the driving operation element  80  such that brake torque according to a braking operation is output to each wheel. The brake device  210  may include a mechanism configured to transfer the hydraulic pressure generated by an operation of the brake pedal included in the driving operation elements  80  to the cylinder via a master cylinder as a backup. Also, the brake device  210  is not limited to the above-described configuration and may be an electronically controlled hydraulic brake device configured to control an actuator in accordance with information input from the ECU controller  126  and transfer the hydraulic pressure of the master cylinder to the cylinder. 
     For example, the steering device  220  includes a steering ECU and an electric motor. For example, the electric motor changes the direction of steerable wheels by applying a force to a rack and pinion mechanism. The steering ECU drives the electric motor in accordance with the information input from the ECU controller  126  or the information input from the driving operation element  80  to change the direction of the steerable wheels. 
     The second recognizer  142  recognizes a state in which the driver is gripping the steering wheel  82  (hereinafter referred to as a “gripping state”) on the basis of a signal input from the steering grip sensor  84 . The gripping state includes, for example, information indicating whether or not the driver is gripping the steering wheel  82 , such as information about a position where the driver is gripping the steering wheel  82  (hereinafter referred to as a “gripping position”) and/or information about the number of grips when the driver is gripping the steering wheel  82  (hereinafter referred to as the “number of grips”). Gripping positions include positions in at least upper, right, lower, and left regions of the steering wheel  82 . The number of grips is “0” when the driver is not gripping the steering wheel  82 , “1” when the driver is gripping the steering wheel  82  with one hand, and “2” when the driver is gripping the steering wheel  82  with both hands. The gripping state is used to determine a driver&#39;s motivation for driving and generate a notification image to be described below. 
     The second recognizer  142  may recognize a direction of a visual line (hereinafter referred to as a “visual line direction”) of the driver in the host vehicle M on the basis of the image input from the driver monitor camera  70 . The visual line direction includes, for example, information indicating whether or not the driver&#39;s visual line when driving the host vehicle M is directed to the front. The second recognizer  142  analyzes an image captured by the driver monitor camera  70 , performs a visual line estimation process, and recognizes the visual line direction of the driver. The visual line direction is used in addition to the gripping state in determining the driver&#39;s motivation for driving. The second recognizer  142  may perform a posture estimation process by analyzing the image captured by the driver monitor camera  70  and recognize a posture of the driver. The visual line direction and the driver&#39;s posture are used to determine whether or not the driver&#39;s state is a state corresponding to a driving mode. 
     The driving assistance executor  144  executes driving assistance for assisting the driver in driving the host vehicle M. As the driving assistance function, for example, functions of driving assistance systems for supporting the driving operation performed by the driver when the host vehicle M is allowed to travel, such as advanced driver-assistance systems (ADAS), are executed. ADAS include some or all functions for supporting specific driving operations such as adaptive cruise control (ACC), low speed following (LSF), a lane keeping assist system (LKAS), and road departure mitigation (RDM). These driving assistance functions are not so-called automated driving functions but are executed in the vehicle system  1  such that driving operations are supported. The driving assistance executor  144  controls the travel driving force output device  200 , the brake device  210 , and the steering device  220  in accordance with the degree (a level) of execution of these driving assistance functions. The driving assistance executor  144  is an example of a “traveling controller.” 
     The traveling mode controller  160  controls the traveling mode when the host vehicle M is traveling in a state in which automated driving and/or driving assistance are being executed. The traveling mode is used to implement traveling performance required when the host vehicle M is allowed to travel by controlling (changing) one or more properties among, for example, various properties related to traveling such as rotational properties of an internal combustion engine or an electric motor, output properties of a travel driving force (torque), properties of a gear shift timing of the transmission, properties of a weight of the steering wheel  82  (output properties of a so-called rotation assist force of power steering or the like), and suspension hardness properties (i.e., damper hardness properties). Traveling modes include, for example, a normal traveling mode, a sport traveling mode, a comfort traveling mode, and the like. The normal traveling mode is, for example, a traveling mode in which the host vehicle M is allowed to travel while balancing traveling performance and comfort. In the normal traveling mode, for example, each property is set as a normal (standard, for example, initial value) property such that a general ride comfort can be obtained with normal traveling performance. The sport traveling mode is, for example, a traveling mode in which the host vehicle M is allowed to travel by prioritizing a process of exhibiting higher traveling performance than in the normal traveling mode. In the sport traveling mode, for example, a setting process of setting the rotational speed of the internal combustion engine, the electric motor, or the like as a higher rotational speed, setting the output of the torque as a higher output, setting a gear shift timing of the transmission to a timing for a high rotational speed range in the internal combustion engine or the electric motor, making the steering wheel  82  heavier, or making a damper stiffer is performed such that sporty ride comfort such as the sharpness of a response and feedback for the driver&#39;s driving operation, the sharpness of acceleration of the host vehicle M, and the high stability of high-speed traveling is obtained. The comfort traveling mode is, for example, a traveling mode in which the host vehicle M is allowed to travel by prioritizing a process of obtaining higher comfort (which may include the possibility of higher mileage or longer-distance traveling) than in the normal traveling mode. In the comfort traveling mode, for example, a setting process of making a change in the rotation of the internal combustion engine or the electric motor slow, setting the gear shift timing of the transmission as an earlier timing, making the steering wheel  82  light, and making the damper softer is performed such that the host vehicle M responds gently to the driver&#39;s driving operation, and a comfortable ride and quietness can be obtained in the host vehicle M. The traveling modes are not limited to those described above. In other words, various traveling modes may be implemented by changing and controlling settings of controllable components. The traveling mode may include, for example, the control (change) of activation of an air conditioning system such as an air conditioner. The traveling mode may be switched by the driver selecting one of prescribed traveling performance options or may be changed by the driver appropriately adjusting adjustable (changeable) properties. 
     The driving control determiner  180  determines on the driving mode of the host vehicle M as one of a plurality of driving modes with different tasks imposed on the driver. Further, the driving control determiner  180  determines a driver&#39;s motivation for driving (hereinafter referred to as the “driver&#39;s motivation”) and determines on the presence or absence of execution and/or the degree of execution of the traveling control in the driving assistance in accordance with a level of the determined motivation of the driver. The degree of execution is, for example, an amount of intervention for intervening traveling control for the driving assistance. In other words, the driving control determiner  180  determines on the amount of intervention in which the traveling control for the driving assistance is allowed to intervene in the driving operation of the driver. More specifically, the driving control determiner  180  reduces the degree of execution of traveling control (reduces the amount of intervention) as the driver&#39;s motivation increases. Thereby, when the driver has a high motivation for driving, i.e., has a high sense of purpose in desiring to perform the driving operation of the host vehicle M, the driver can drive the host vehicle M according to his or her own sense of purpose. The degree of execution is not limited to the amount of intervention of traveling control. For example, the degree of execution may be associated with a process of changing a threshold value for executing traveling control to the side where it is easy to execute/difficult to execute the traveling control, a process of changing the strength (gain) of the traveling control, a process of changing the sharpness of a response when the traveling control is performed, and a process of changing a condition for starting the traveling control of the driving assistance such as a process of changing an upper limit value when the execution of the traveling control starts. The driver&#39;s motivation and/or the presence or absence of execution of the traveling control and/or the degree of execution of the traveling control in the driving assistance are used to generate the notification image to be described below. 
     The driving control determiner  180  determines the driver&#39;s motivation according to a combination of the gripping position and the number of grips included in the gripping state. The driving control determiner  180  determines that the driver&#39;s motivation increases as the number of grips increases. When the number of grips is the same, the driving control determiner  180  determines that the driver&#39;s motivation is higher when the gripping position is the right and/or left. The driving control determiner  180  reduces the amount of intervention of driving assistance as the determined motivation of the driver increases. That is, the driving control determiner  180  limits the execution of driving assistance or decreases the degree of execution as the determined motivation of the driver increases. 
     The driving control determiner  180  may further determine the driver&#39;s motivation by combining the gripping position and the number of grips with a driver&#39;s visual line direction. The driving control determiner  180  determines that the driver&#39;s motivation is high when the visual line direction of the driver is the front of the host vehicle M in the traveling direction. In addition to the front of the host vehicle M, visual line directions assumed to be the front of the host vehicle M in the traveling direction of the driver include a plurality of prescribed visual line directions in which it is assumed that the host vehicle M is being driven. More specifically, the visual line directions in front of the host vehicle M in the traveling direction include, for example, a visual line direction when a rearward situation outside of the vehicle is temporarily confirmed with a rearview mirror of the cabin, a side mirror outside of the vehicle, or the like, a visual line direction when a traveling state is temporarily confirmed with a speedometer indicating the traveling speed of the host vehicle M, a tachometer indicating the number of revolutions (a rotational speed) of the internal combustion engine provided in the host vehicle M, or the like in addition to a visual line direction when the front is confirmed through a front windshield such as a front window glass. The driving control determiner  180  may determine that the driver is facing the front when the visual line direction of the driver is any one of the above-described visual line directions. The driving control determiner  180  may reduce the amount of intervention of driving assistance when the visual line direction of the driver is the front. 
     The traveling mode controller  160  may determine on the traveling mode in accordance with the driver&#39;s motivation determined by the driving control determiner  180 . In this case, the traveling mode controller  160  determines on a traveling mode in which the driver can perform a driving operation more suitable for the sense of purpose of the driving operation when the determined motivation of the driver becomes higher. For example, the traveling mode controller  160  determines on the traveling mode as the sport traveling mode when the driver&#39;s motivation is high and determines on the traveling mode as the comfort traveling mode when the driver&#39;s motivation is low. 
     The notification image generator  192  generates a notification image on the basis of the driver&#39;s gripping state of the steering wheel  82  recognized by the second recognizer  142 , the driver&#39;s motivation determined by the driving control determiner  180 , and the presence or absence of execution of the traveling control and/or the degree of execution of the traveling control in the driving assistance determined on by the driving control determiner  180 . The notification image is an image for providing a notification of the gripping state, the driver&#39;s motivation, the degree of execution of driving assistance, and the like in a form in which it is easy for the driver to recognize visually them. The display processor  190  causes the display device  32  provided in the HMI  30  to display the notification image generated by the notification image generator  192 . 
       FIG.  3    is a diagram showing an example of a notification image. In  FIG.  3   , the entire image display area of the display device  32  is assumed to be the entire image area Ia of the notification image IM and an example of the notification image IM in which information which is presented to the driver (or of which the driver is notified) is displayed together with information indicating a current traveling state of the host vehicle M such as a speedometer, a tachometer, shift position display (“D”=drive range in  FIG.  3   ), traveling mode display (“NORMAL”=normal traveling mode in  FIG.  3   ), an ACC icon, inter-vehicle distance setting display, and an LKAS icon is shown. The notification image IM is not limited to the display format shown in  FIG.  3   . For example, the notification image IM may be displayed in an area between the speedometer and the tachometer displayed at prescribed positions on the left and right in the entire image display area of the display device  32 . 
     In the image area Ia, the notification image IM includes, for example, a first graphic F 1  based on a circle and a second graphic F 2  of a circular shape on the outer periphery of the first graphic F 1  (outside of the circle in the radial direction). In  FIG.  3   , the first graphic F 1  of a state in which traveling speed information Isp indicating the current traveling speed of the host vehicle M is displayed is shown and the second graphic F 2  having three notches is shown. That is, the case where three arcs of a second graphic F 2 - 1  on the upper side, a second graphic F 2 - 2  on the right side, and a second graphic F 2 - 3  on the left side form the second graphic F 2  of the circular shape is shown in  FIG.  3   . The second graphic F 2  may have a gradual change in brightness or color tone (a so-called gradation) instead of the notch. The notch (including the gradation) in the second graphic F 2  does not necessarily have to be provided. In other words, the notch need not be provided in the second graphic F 2 . The second graphic F 2 - 2  is an example of the “right area” and the second graphic F 2 - 3  is an example of the “left area.” Unless otherwise specified in the following description, the second graphic F 2 - 1 , the second graphic F 2 - 2 , and the second graphic F 2 - 3  are not distinguished and the overall shape including the notch is assumed to be the circular shape of the second graphic F 2 . 
     The first graphic F 1  indicates the gripping position and the number of grips of the steering wheel  82  associated with the driver and the level of the driver&#39;s motivation according to a shape thereof. The notification image generator  192  notifies the driver of the gripping position and the number of grips recognized by the second recognizer  142  by deforming the first graphic F 1  such that the location of the first graphic F 1  corresponding to a part of the steering wheel  82  gripped by the driver is expanded. The notification image generator  192  indicates a state in which the driver is gripping the left and right sides of the steering wheel  82  with both hands, for example, by expanding the right and left sides of the first graphic F 1 . The notification image generator  192  notifies the driver of the driver&#39;s motivation determined by the driving control determiner  180  by changing the size of the first graphic F 1 , i.e., by changing the length of the diameter of the circle. For example, the notification image generator  192  indicates that the driver&#39;s motivation is high by increasing the diameter and increasing an overall size of the first graphic F 1  and indicates that the driver&#39;s motivation is low by decreasing the diameter and decreasing the overall size of the first graphic F 1 . The notification image generator  192  may notify the driver of the driver&#39;s motivation determined by the driving control determiner  180  by changing the color of the entire image area Ia of the notification image IM and the color of the first graphic F 1 . For example, the notification image generator  192  may indicate that the driver&#39;s motivation is high by setting the color of the image area Ia as a color that is easier for the driver to recognize in the field of view (for example, a color that tends to be red) even if the driver does not directly view the notification image IM and may indicate that the driver&#39;s motivation is low by setting the color of the image area Ia as a color for enabling the driver to relax more easily (for example, a color that tends to be blue). In this way, the notification image generator  192  visually notifies the driver of the gripping state of the steering wheel  82  or the level of the driver&#39;s motivation according to a combination of the shape of the first graphic F 1 , the size of the first graphic F 1 , and the color of the image area Ia or the first graphic F 1  described above. 
     The second graphic F 2  indicates the presence or absence of execution of the traveling control and the degree of execution of the traveling control according to its shape and a condition of separation from the first graphic F 1 . The notification image generator  192  notifies the driver of the degree of execution of the traveling control based on the driving assistance determined on by the driving control determiner  180  by changing a distance between the first graphic F 1  and the circle of the second graphic F 2 , more specifically, a distance from the inner circle of the second graphic F 2 . The notification image generator  192  may notify the driver of the degree of execution of the traveling control based on the driving assistance by changing the thickness of the circle of the second graphic F 2 , more specifically, the difference between the length of the diameter of the inner circle and the length of the diameter of the outer circle. The notification image generator  192  may notify the driver of the degree of execution of the traveling control based on the driving assistance by changing the shade of the display of the circle of the second graphic F 2  to make it easier or harder to view the second graphic F 2 . In other words, the notification image generator  192  may notify the driver of the degree of execution of the traveling control based on the driving assistance by changing the degree of definition of the second graphic F 2 . The notification image generator  192  notifies the driver of the presence or absence of the traveling control based on the driving assistance determined on by the driving control determiner  180  by switching a mode between a display mode and a non-display mode for the second graphic F 2 . The notification image generator  192  may notify the driver of the presence or absence of execution of the traveling control and/or the degree of execution of the traveling control in the driving assistance determined on by the driving control determiner  180  by changing the color of the second graphic F 2  or blinking the second graphic F 2 . For example, the notification image generator  192  may indicate that the degree of execution of the traveling control based on the driving assistance is low by setting the color of the second graphic F 2  as a color that is easier for the driver to recognize in the field of view (for example, a color that tends to be red) even if the driver does not directly view the notification image IM and may indicate that the degree of execution of the traveling control based on the driving assistance is high by setting the color of the second graphic F 2  as a color for enabling the driver to relax more easily (for example, a color that tends to be blue). For example, the notification image generator  192  may indicate that the degree of execution of the traveling control based on the driving assistance is low by blinking the second graphic F 2  and may indicate that the degree of execution of the traveling control based on the driving assistance is high by displaying (lighting up) the second graphic F 2  all the time. In this way, the notification image generator  192  visually notifies the driver of the presence or absence of execution of the traveling control and/or the degree of execution of the traveling control in the driving assistance according to a combination of the shape of the second graphic F 2 , the distance between the first graphic F 1  and the second graphic F 2 , the color of the second graphic F 2 , and the blinking or lighting-up of the second graphic F 2  described above. 
       FIG.  4    is a diagram showing an example of corresponding relationships between driving modes, driving assistance, and traveling modes. In  FIG.  4   , an example of relationships between the driving modes controlled by the vehicle control device  100 , the driver&#39;s motivation, the presence or absence of driving assistance or the degree of execution of the driving assistance, and the traveling modes is shown. 
     First, the driving modes will be described. For example, there are five modes from mode A to mode E as the driving modes of the host vehicle M. The degree of automation of the driving control of the host vehicle M in the driving modes is highest in mode A, lower in the order of mode B, mode C, and mode D, and lowest in mode E. In contrast, a task imposed on the driver is lightest in mode A, heavier in the order of mode B, mode C, and mode D, and heaviest in mode E. Because traveling control related to automated driving and driving assistance is not performed in mode E, the driving control determiner  180  is responsible for shifting the driving mode to driving by the driver (so-called manual driving) in control related to the decision of the driving mode. The content of the driving modes will be exemplified below. 
     In mode A, the state is a state in which a driving control level related to the automated driving is highest (hereinafter referred to as an “automated driving state”) and neither forward monitoring nor gripping of the steering wheel  82  (a steering grip in  FIG.  3   ) is imposed on the driver. However, even in mode A, the driver is required to be in a posture where the fast shift to manual driving is enabled in response to a request from the system centered on the automated driving controller  120  and the driving control determiner  180 . The term “automated driving” as used herein indicates that both steering and acceleration/deceleration are controlled independently of the operation of the driver. The term “forward region or direction” indicates a space in a traveling direction of the host vehicle M that is visually recognized via the front windshield. Mode A is a driving mode in which the host vehicle M travels at a prescribed speed (for example, about 50 [km/h]) or less on a motorway such as an expressway and which can be executed when a condition in which there is a tracking target preceding vehicle or the like is satisfied. Mode A may be referred to as a traffic jam pilot (TJP). When this condition is no longer satisfied, the driving control determiner  180  changes the driving mode of the host vehicle M to mode B. 
     In mode B, a driving control level related to the automated driving is lower than that of mode A and a task of monitoring a forward direction of the host vehicle M (hereinafter referred to as forward monitoring) is imposed on the driver, but a task of gripping the steering wheel  82  is not imposed on the driver. In mode C, a driving control level related to the automated driving is lower than that of mode B and a forward monitoring task and a task of gripping the steering wheel  82  are imposed on the driver. In mode D, a driving control level related to the automated driving is lower than that of mode C and a task in which a certain degree of driving operation is required for at least one of steering and acceleration/deceleration of the host vehicle M is imposed on the driver. In mode E, a driving control level related to the automated driving is lower than that of mode D and manual driving in which a task requiring a driving operation for both steering and acceleration/deceleration is imposed on the driver is performed. In mode E, a task of monitoring a forward direction of the host vehicle M is naturally imposed on the driver. 
     The automated driving controller  120  (more specifically, the ECU controller  126 ) executes an automated lane change corresponding to the driving mode determined on by the driving control determiner  180 . Automated lane changes include an automated lane change (1) due to a system request and an automated lane change (2) due to a driver request. Examples of the automated lane change (1) include an automated lane change for passing and an automated lane change for traveling toward a destination (an automated lane change based on a change in a recommended lane) performed when the speed of the preceding vehicle is less than the speed of the host vehicle by a reference level or higher. In the automated lane change (2), if a condition related to speed, a positional relationship with a nearby vehicle, or the like is satisfied, the host vehicle M is allowed to change the lane in an operation direction when the direction indicator has been operated by the driver. 
     The automated driving controller  120  does not execute either of the automated lane changes (1) and (2) in mode A. The automated driving controller  120  executes both automated lane changes (1) and (2) in modes B and C. The automated driving controller  120  does not execute the automated lane change (1) but executes the automated lane change (2) in mode D. In mode E, neither of the automated lane changes (1) and (2) is executed by the automated driving controller  120 . 
     The driving control determiner  180  changes the driving mode of the host vehicle M to a driving mode in which the task is heavier when the task related to the determined driving mode (hereinafter, the present driving mode) is not executed by the driver. Thus, the driving control determiner  180  monitors the driver&#39;s state for changing the driving mode and determines whether or not the driver&#39;s state is a state corresponding to the task. For example, the driving control determiner  180  determines whether or not the driver is in a posture where he/she cannot shift the driving to manual driving in response to a request from the system on the basis of a posture of the driver recognized by the second recognizer  142 . The driving control determiner  180  determines whether or not the driver is performing forward monitoring on the basis of a visual line direction recognized by the second recognizer  142 . The driving control determiner  180  performs various types of processes for changing the driving mode. For example, the driving control determiner  180  instructs the automated driving controller  120  (more specifically, the action plan generator  124 ) to generate a target trajectory for stopping the vehicle at the road shoulder or instructs the automated driving controller  120  to control the HMI  30  such that the driver is prompted to perform an action. 
     For example, in mode A, when the driver is in a posture where he/she cannot shift the driving to manual driving in response to a request from the system (for example, when he/she continues to look outside an allowable area or when a sign that driving is difficult is detected), the driving control determiner  180  performs a control process of changing the driving mode of the host vehicle M to mode B or lower and instructing the automated driving controller  120  to prompt the driver to shift the driving to manual driving using the HMI  30  and generate a target trajectory for causing the host vehicle M to gradually stop close to the road shoulder when the driver does not respond and stopping the automated driving. After the automated driving is stopped, the driving control determiner  180  changes the driving mode of the host vehicle M to mode D or E. Thereby, the host vehicle M can be started according to the manual driving of the driver. Hereinafter, the same is true for “stopping of automated driving.” When the driver is not performing forward monitoring in mode B, the driving control determiner  180  performs a control process of changing the driving mode of the host vehicle M to mode C or lower and instructing the automated driving controller  120  to prompt the driver to perform the forward monitoring using the HMI  30  and generate a target trajectory for causing the host vehicle M to gradually stop close to the road shoulder when the driver does not respond and stopping the automated driving. When the driver is not performing forward monitoring or is not gripping the steering wheel  82  in mode C, the driving control determiner  180  performs a control process of changing the driving mode of the host vehicle M to mode D or lower and instructing the automated driving controller  120  to prompt the driver to perform the forward monitoring and/or grip the steering wheel  82  using the HMI  30  and generate a target trajectory for causing the host vehicle M to gradually stop close to the road shoulder when the driver does not respond and stopping the automated driving. 
     Next, the driving assistance will be described. The driver is expected to change a gripping position and the number of grips on the steering wheel  82  according to his or her motivation level for driving. In  FIG.  4   , an example of the gripping state of the steering wheel  82  according to the motivation level of the driver is schematically shown. The driver&#39;s motivation is also considered to be associated with the driving mode of the host vehicle M. For example, it is considered that motivation is highest in mode E, lower in the order of mode D, mode C, and mode B, and lowest in mode A. Thus, because the driving control determiner  180  does not perform driving assistance on the assumption that the driver does not desire driving assistance in mode E corresponding to manual driving and the level of driving control associated with automated driving is highest in mode A, driving assistance is not performed by the driving assistance controller  140  on the assumption that the driving control is performed by the automated driving controller  120 . The driving control determiner  180  determines the motivation of the driver in modes B to D and determines on the degree of execution of traveling control based on driving assistance in accordance with a level of the determined motivation of the driver. 
     As described above, the driving control determiner  180  determines the driver&#39;s motivation according to a combination of the gripping position and the number of grips and determines on the degree of execution of traveling control based on driving assistance in accordance with the level of the determined motivation of the driver. The driving assistance includes, for example, longitudinal system assistance and lateral system assistance. The longitudinal system assistance is driving assistance for performing traveling control in the traveling direction of the host vehicle M and the lateral system assistance is driving assistance for performing traveling control in the vehicle width direction of the host vehicle M. The driving control determiner  180  changes (sets) the amount of intervention for each type of driving assistance. In  FIG.  4   , an example of longitudinal system assistance and lateral system assistance that are executed in accordance with the level of the determined motivation of the driver is schematically shown. In  FIG.  4   , an example of an amount of intervention in the lateral system assistance is schematically shown. 
     In the longitudinal system assistance, the driving control determiner  180  changes, for example, the degree of execution of ACC. However, in the longitudinal system assistance, the driving control determiner  180  makes a change in accordance with the level of the motivation of the driver using the inter-vehicle distance from the preceding vehicle as an amount of intervention without allowing a process of following the preceding vehicle traveling in front of the host vehicle M in an ACC process. More specifically, the driving control determiner  180  changes the inter-vehicle distance to a shorter distance because the driver himself/herself can recognize the preceding vehicle when the driver&#39;s motivation is high and changes the inter-vehicle distance to a longer distance because the driver himself/herself is unlikely to recognize the preceding vehicle when the driver&#39;s motivation is low. Thereby, the vehicle control device  100  can control the brake device  210  at an earlier stage especially when the host vehicle M approaches the preceding vehicle in a state in which the driver&#39;s motivation is low. The driving control determiner  180  performs a process of setting ACC (setting the inter-vehicle distance) like a process of setting ACC in mode A when the driver&#39;s motivation is low in the longitudinal system assistance. Thereby, the vehicle control device  100  can eliminate the difference in the behavior of the host vehicle M in switching between mode A and the ACC driving assistance executed in the most recent mode B, i.e., can seamlessly switch the driving mode. 
     In the lateral system assistance, for example, the driving control determiner  180  changes degrees of execution of LKAS and RDM. More specifically, when the driver&#39;s motivation is high, the driving control determiner  180  makes a change for preventing LKAS from being executed (limits the execution of LKAS) and makes a change for executing only RDM such that the driver himself/herself can travel at any position in the vehicle width direction within the traveling lane. On the other hand, when the driver&#39;s motivation is low, the driving control determiner  180  makes a change for executing LKAS and RDM such that the vehicle is allowed to travel in the center of the traveling lane as a reference. At this time, the driving control determiner  180  changes a range (a threshold value) of the distance in the vehicle width direction in LKAS according to the level of the driver&#39;s motivation. In other words, the driving control determiner  180  changes an amount of intervention in which LKAS intervenes in the lateral system assistance according to the level of the driver&#39;s motivation. More specifically, the driving control determiner  180  shortens the distance in the vehicle width direction in which traveling is possible (i.e., narrows the width: threshold value=“small”) such that the vehicle is allowed to travel more centrally in the traveling lane when the driver&#39;s motivation is low and lengthens the distance in the vehicle width direction in which traveling is possible (i.e., widens the width: threshold value=“large”) such that the vehicle is allowed to travel within a certain range from the center of the traveling lane when the driver&#39;s motivation is high. More specifically, the amount of intervention in which LKAS intervenes in the driver&#39;s driving operation increases when the driver&#39;s motivation is low and decreases when the driver&#39;s motivation is high. Thereby, when the driver&#39;s motivation increases to some extent, the driver can drive the vehicle at any position within the range of distance in the vehicle width direction based on the threshold value. The driving control determiner  180  performs a process of setting LKAS and RDM in the case of a low motivation of the driver like a process of setting LKAS and RDM in mode A even in the lateral system assistance. Thereby, the vehicle control device  100  can seamlessly switch between mode A and driving assistance of LKAS and RDM executed in the most recent mode B, even in traveling control of the host vehicle M in the vehicle width direction. 
     The driving assistance controller  140  (more specifically, the driving assistance executor  144 ) executes traveling control corresponding to the driving assistance (i.e., the longitudinal system assistance, the lateral system assistance, and the amount of intervention) determined on by the driving control determiner  180 . When the traveling state of the host vehicle M deviates or is likely to deviate from the range of driving assistance being executed, the driving assistance controller  140  may be configured to control the HMI  30  for prompting the driver to perform a driving operation such that a caution or a warning is given. The driving control determiner  180  may be configured to issue an instruction for giving the caution or the warning to the driver. 
     Next, the traveling mode will be described. The driving control determiner  180  allows the driver to change the traveling mode in mode E, which is manual driving, and determines on the traveling mode as the comfort traveling mode in mode A. In modes B to D, the driving control determiner  180  determines on the traveling mode in accordance with the level of the determined motivation of the driver. 
     As described above, the driving control determiner  180  determines on the traveling mode as the sport traveling mode when the driver&#39;s motivation is high and determines on the traveling mode as the comfort traveling mode when the driver&#39;s motivation is low. In  FIG.  4   , an example of the traveling mode determined on in accordance with the level of the determined motivation of the driver and an example of the behavior (response and feedback) of the steering wheel  82  during driving in the traveling mode are schematically shown. 
     The traveling mode controller  160  executes control for changing various properties related to traveling of the host vehicle M such that the traveling mode determined on by the driving control determiner  180  is achieved. Thereby, the response and feedback of the steering wheel  82  while the host vehicle M is traveling increase in the sport traveling mode and decrease in the comfort traveling mode. Even if the host vehicle M is traveling in the traveling mode determined on and changed by the driving control determiner  180  in accordance with the driver&#39;s motivation, the driver can change the traveling mode. Thereby, the vehicle control device  100  can cause the host vehicle M to travel in a traveling mode that matches the driver&#39;s motivation and the driver&#39;s desires. 
     [Example of Method of Determining Driver&#39;s Motivation] 
       FIG.  5    is a diagram showing an example of a configuration in which the gripping state of the steering wheel  82  by the driver is recognized. In  FIG.  5   , an example of a configuration in which the driver&#39;s gripping position is recognized by dividing the steering wheel  82  into four parts when the steering wheel  82  has an annular shape is shown. The second recognizer  142  detects whether or not the driver is gripping each of a first gripping part GP 1  in an upper region of the steering wheel  82 , a second gripping part GP 2  in a right region thereof, a third gripping part GP 3  in a lower region thereof, and a fourth gripping part GP 4  in a left region thereof on the basis of a signal input from the steering grip sensor  84  attached to the steering wheel  82 . Further, the second recognizer  142  detects whether the number of parts gripped by the driver is one or two. The second recognizer  142  recognizes the gripping position and the number of grips on the basis of a detection result. The second recognizer  142  outputs information about a gripping state including the recognized gripping position and the recognized number of grips to each of the driving control determiner  180  and the display processor  190 . 
       FIG.  6    is a diagram showing an example of determination patterns for determining the driver&#39;s motivation. In  FIG.  6   , an example in which the driving control determiner  180  determines the driver&#39;s motivation as one of seven levels, for example, from level 1 to level 7, is shown. In relation to the level of the driver&#39;s motivation, level 1 is lowest, level 2, level 3, level 4, level 5, and level 6 are higher in that order, and level 7 is highest. In  FIG.  6   , the position (a gripping position) where the driver grips the steering wheel  82  is schematically shown. The driving control determiner  180  determines the motivation of the driver when the execution of the driving assistance in the vehicle control device  100  is effective (the ADAS function is turned “on”) and the driving mode is one of modes B to D. 
     When the driver has turned “off” the ADAS function, the driving control determiner  180  sets the driving mode as mode E that is manual driving and determines that the driver&#39;s motivation is level 7 regardless of the gripping state of the steering wheel  82  associated with the driver or a visual line direction of the driver. Level 7 is a level at which it can be determined that the driver is in a state in which a safety function or driving assistance based on the ADAS function is not desired because the motivation is high. 
     The driving control determiner  180  determines that the motivation of the driver is level 6 when the gripping state recognized by the second recognizer  142  is associated with the presence or absence of gripping=“presence,” the number of grips=“2,” the gripping position=“right and left regions (the second gripping part GP 2  and the fourth gripping part GP 4  shown in  FIG.  5   ),” and the visual line direction=“front.” That is, the driving control determiner  180  determines that the level is level 6 when it is recognized that the driver is facing the front and gripping the left and right regions of the steering wheel  82  with both hands. Level 6 is, for example, a level at which it can be determined that the driver himself/herself is in an optimal posture capable of coping with all situations in traveling of the host vehicle M in a state in which the driver is enjoying driving the host vehicle M, a state in which the driver is seeking a sense of unity with the host vehicle M, or the like. 
     The driving control determiner  180  determines that the motivation of the driver is level 5 when the gripping state recognized by the second recognizer  142  is associated with the presence or absence of gripping=“presence,” the number of grips=“2,” the gripping position=“upper and/or lower regions (the first gripping part GP 1  and/or the third gripping part GP 3  shown in  FIG.  5   ),” and the visual line direction=“front.” That is, the driving control determiner  180  determines that the level is level 5 when it is recognized that the driver is facing the front and gripping the upper and/or lower regions of the steering wheel  82  with both hands of the driver. Level 5 is, for example, a level at which it can be determined that reliable traveling is desired instead of unreasonable driving in a state in which the driver prefers to drive the host vehicle M, but does not desire a sense of unity with the host vehicle M or the like. 
     The driving control determiner  180  determines that the motivation of the driver is level 4 when the gripping state recognized by the second recognizer  142  is associated with the presence or absence of gripping=“presence,” the number of grips=“1,” the gripping position=“right or left region (the second gripping part GP 2  or the fourth gripping part GP 4  shown in  FIG.  5   ),” and the visual line direction=“front.” That is, the driving control determiner  180  determines that the level is level 4 when it is recognized that the driver is facing the front and gripping the right or left region of the steering wheel  82  with one hand. Level 4 is, for example, a level at which it can be determined that the driver is in a posture in which the state can return to a state in which the driving operation can be performed quickly (for example, a state in which it is determined that the level is level 5 or 6) due to a traveling state of the host vehicle M in a state in which the driver is slightly relaxed and one hand not used in gripping is placed on the shift lever or the like. 
     The driving control determiner  180  determines that the motivation of the driver is level 3 when the gripping state recognized by the second recognizer  142  is associated with the presence or absence of gripping=“presence,” the number of grips=“1,” the gripping position=“upper or lower region (the first gripping part GP 1  or the third gripping part GP 3  shown in  FIG.  5   ),” and the visual line direction=“front.” That is, the driving control determiner  180  determines that the level is level 3 when it is recognized that the driver is facing the front and gripping the upper or lower region of the steering wheel  82  with one hand of the driver. Level 3 is, for example, a level at which it can be determined that the driver is enjoying information provided by an entertainment device or the like provided in the host vehicle M along with driving of the host vehicle M in a state in which the driver is relaxed or is continuing simple driving for a long time or the like. 
     The driving control determiner  180  determines that the motivation of the driver is level 2 when the gripping state recognized by the second recognizer  142  is associated with the presence or absence of gripping=“absence,” the number of grips=“0,” the gripping position=“absence,” and the visual line direction=“front.” That is, the driving control determiner  180  determines that the level is level 2 when it is recognized that the driver is facing the front, but is not gripping the steering wheel  82 . Level 2 is, for example, a level at which it can be determined that the driver is not gripping the steering wheel  82 , i.e., is in a so-called hands-off state, and is in a state in which the physical load is released, but the driver is in a posture in which the state can return to a state in which the driving operation can be performed quickly (a state in which it is determined that the level is level 5 or 6) due to a traveling state of the host vehicle M. 
     When the driving mode is mode A, i.e., when the level of driving control related to automated driving is highest, the driving control determiner  180  determines that the driver&#39;s motivation is level 1 regardless of the driver&#39;s gripping state of the steering wheel  82  and the driver&#39;s visual line direction. Level 1 is, for example, a level at which it can be determined that the state is a state in which the driver abandons the task of the driving operation temporarily such as a state in which the driver looks away to operate an entertainment device provided in the host vehicle M or a state in which the driver abandons the task of the driving operation for a long time (here, a posture in which the driving is shifted to manual driving quickly in response to a request from the system) by switching the driving control to the driving control of the automated driving in the host vehicle M. 
     Thus, the driving control determiner  180  determines the driver&#39;s current motivation on the basis of the gripping state of the steering wheel  82  and the visual line direction of the driver recognized by the second recognizer  142 . Although a combination of several gripping parts as gripping parts of the steering wheel  82  for each motivation of the driver is shown in  FIG.  6   , the gripping part of the steering wheel  82  when the driver drives the host vehicle M is not limited to a combination of gripping parts shown in  FIG.  6   . For example, it is also conceived that the driver grips each of the first gripping part GP 1  and the second gripping part GP 2  or grips each of the third gripping part GP 3  and the fourth gripping part GP 4 . In this case, the driving control determiner  180  may determine the motivation of the driver in correspondence with any combination of the gripping parts shown in  FIG.  6   . For example, when the driver is gripping each of the first gripping part GP 1  and the second gripping part GP 2 , the driving control determiner  180  may determine that the driver&#39;s motivation is level 6 because one hand of the driver is gripping the second gripping part GP 2  and may determine that the driver&#39;s motivation is level 5 because one hand of the driver is gripping the first gripping part GP 1 . 
     [Example of Notification Image for Each Driver&#39;s Motivation] 
       FIG.  7    is a diagram showing an example of the notification image IM corresponding to the driver&#39;s motivation. As described above, the display processor  190  (more specifically, the notification image generator  192 ) changes the color of the entire image area Ia of the notification image IM or the first graphic F 1  or deforms the first graphic F 1  such that the driver is notified of the gripping position and the number of grips recognized by the second recognizer  142  and the driver&#39;s motivation determined by the driving control determiner  180 . In  FIG.  7   , an example of the notification image IM generated by the notification image generator  192  for each driver&#39;s motivation determined by the driving control determiner  180  is shown. In  FIG.  7   , only the image area Ia of the notification image IM and the first graphic F 1  included in the image area Ia are shown. 
     When the driver&#39;s motivation is level 7, the notification image generator  192  changes the color of the image area Ia to, for example, “black,” such that a notification of manual driving is provided. The notification image generator  192  does not display the circle of the first graphic F 1  within the image area Ia. In the notification image IM of level 7 shown in  FIG.  7   , a state in which the traveling speed information Isp is displayed at the position where the circle of the first graphic F 1  is displayed is shown. 
     When the driver&#39;s motivation is level 6, the notification image generator  192  changes the color of the image area Ia to, for example, “red” that is easily recognized by the driver during driving, and maximizes the size of the first graphic F 1  such that a notification indicating that the driver&#39;s motivation is highest is provided. In other words, the notification image generator  192  maximizes the diameter of the circle of the first graphic F 1 . As shown in  FIG.  7   , the notification image generator  192  may also change the color of the first graphic F 1  to a color similar to that of the image area Ia. The color of the first graphic F 1  is similar to those of other levels. The notification image generator  192  deforms the first graphic F 1  such that two locations of the right side and the left side corresponding to parts in which the driver is gripping the steering wheel  82  are expanded in the first graphic F 1  to provide a notification indicating that positions where the driver is gripping the steering wheel  82  are “left and right positions (the second gripping part GP 2  and the fourth gripping part GP 4  shown in  FIG.  5   ).” Even in the notification image IM of level 6 shown in  FIG.  7   , a state in which the traveling speed information Isp is displayed within the first graphic F 1  is shown. The display of the traveling speed information Isp within the first graphic F 1  is similar to those of other levels. The length of the diameter of the circle of the first graphic F 1  at level 6 is an example of a “first length.” 
     When the driver&#39;s motivation is level 5, the notification image generator  192  changes the color of the image area Ia to, for example, “light brown” that is easily recognized by the driver during driving, and makes the size of the first graphic F 1  smaller than that of level 6 such that a notification indicating that the driver&#39;s motivation is high is provided. In other words, the notification image generator  192  makes the diameter of the circle of the first graphic F 1  shorter than the diameter of the circle of level 6. The notification image generator  192  deforms the first graphic F 1  such that two locations of the upper side and/or the lower side corresponding to parts in which the driver is gripping the steering wheel  82  are expanded in the first graphic F 1  to provide a notification indicating that positions where the driver is gripping the steering wheel  82  are “upper and lower positions (the first gripping part GP 1  and/or the third gripping part GP 3  shown in  FIG.  5   ).” In the notification image IM of level 5 shown in  FIG.  7   , an example of the first graphic F 1  deformed to expand the upper side is shown. The length of the diameter of the circle of the first graphic F 1  at level 5 is an example of a “second length.” 
     When the driver&#39;s motivation is level 4, the notification image generator  192  changes the color of the image area Ia to, for example, “dark blue,” and makes the size of the first graphic F 1  smaller than that of level 5 such that a notification indicating that the driver&#39;s motivation is normal (neither high nor low) but is slightly high is provided. That is, the diameter of the circle of the first graphic F 1  is made shorter than the diameter of the circle of level 5. The notification image generator  192  deforms the first graphic F 1  such that the location of the right side or the left side corresponding to a part in which the driver is gripping the steering wheel  82  is expanded in the first graphic F 1  to provide a notification indicating that a position where the driver is gripping the steering wheel  82  is a “right or left position (the second gripping part GP 2  or the fourth gripping part GP 4  shown in  FIG.  5   ).” In the notification image IM of level 4 shown in  FIG.  7   , an example of the first graphic F 1  deformed such that the right side is expanded is shown. The length of the diameter of the circle of the first graphic F 1  at level 4 is an example of a “third length.” 
     When the driver&#39;s motivation is level 3, the notification image generator  192  changes the color of the image area Ia to, for example, “blue” for enabling the driver to relax easily, and makes the size of the first graphic F 1  smaller than that of level 4 such that a notification indicating that the driver&#39;s motivation is normal but is slightly low is provided. That is, the diameter of the circle of the first graphic F 1  is made shorter than the diameter of the circle of level 4. The notification image generator  192  deforms the first graphic F 1  such that the location of the upper side or the lower side corresponding to a part in which the driver is gripping the steering wheel  82  is expanded in the first graphic F 1  to provide a notification indicating that a position where the driver is gripping the steering wheel  82  is an “upper or lower position (the first gripping part GP 1  or the third gripping part GP 3  shown in  FIG.  5   ).” In the notification image IM of level 3 shown in  FIG.  7   , an example of the first graphic F 1  deformed to expand the lower side is shown. The length of the diameter of the circle of the first graphic F 1  at level 3 is an example of a “fourth length.” 
     When the driver&#39;s motivation is level 2, the notification image generator  192  changes the color of the image area Ia to, for example, “light blue” for enabling the driver to relax more easily, and makes the size of the first graphic F 1  smaller than that of level 3 such that a notification indicating that the driver&#39;s motivation is low is provided. In other words, the notification image generator  192  makes the diameter of the circle of the first graphic F 1  smaller than the diameter of the circle of level 3. Because the driver is not gripping the steering wheel  82  at level 2, the notification image generator  192  does not deform the circle of the first graphic F 1  for a notification of this fact. In the notification image IM of level 2 shown in  FIG.  7   , an example of the first graphic F 1  which is not deformed and remains as a circle is shown. The length of the diameter of the circle of the first graphic F 1  at level 2 is an example of a “fifth length.” 
     When the driver&#39;s motivation is level 1, the notification image generator  192  changes the color of the image area Ia to, for example, “gray,” such that a notification indicating that driving control for automated driving is being executed in the host vehicle M is provided. As in the case of level 2, the notification image generator  192  does not deform the circle of the first graphic F 1  such that a notification indicating that the driver is not gripping the steering wheel  82  is provided. Even at level 1, the diameter of the circle of the first graphic F 1  is the same as the diameter of the circle at level 2. In the notification image IM of level 1 shown in  FIG.  7   , instead of the traveling speed information Isp displayed within the first graphic F 1  at levels 7 to 2, a state in which text information of “AUTOMATED DRIVE” indicating that driving control for automated driving is being executed is shown. 
     In this way, the notification image generator  192  notifies the driver of the level of the determined motivation of the driver or the recognized gripping state of the steering wheel  82  associated with the driver in a visually recognizable form according to a combination of the color of the image area Ia and the color, the shape, the size, or the like of the first graphic F 1 . More specifically, the notification image generator  192  changes the color of the image area Ia (which may include the first graphic F 1 ) to a color that is more easily recognized by the driver as the driver&#39;s motivation increases. Furthermore, the notification image generator  192  increases the size of the first graphic F 1  as the driver&#39;s motivation increases. The notification image generator  192  indicates the driver&#39;s gripping position of the steering wheel  82  by deforming the shape of the first graphic F 1 . 
     [Method of Determining on Degree of Execution of Driving Assistance and Examples of Notification Images for Each Degree of Execution] 
       FIG.  8    is a diagram showing an example of the degree of execution of driving assistance and a notification image corresponding to the driver&#39;s motivation. In  FIG.  8   , an example in which the driving control determiner  180  changes (sets) the degree of execution of driving assistance (an amount of intervention of traveling control of driving assistance) and the traveling mode for each of the determined motivations of the driver is shown. More specifically, in  FIG.  8   , an example in which amounts of intervention of ACC and LSF as the longitudinal system assistance are set, amounts of intervention of LKAS and RDM as the lateral system assistance are set, and the traveling mode is changed is shown. In  FIG.  8   , an example of a notification image for notifying the driver that ACC and LSF are being executed is shown. The notification image may be displayed together with the notification image IM on the display device  32 , for example, as shown in  FIG.  3   . In  FIG.  8   , an example of a state in which the travelable distance (range) in the vehicle width direction is limited by LKAS and RDM is schematically shown. In  FIG.  8   , an example of a notification image for notifying the driver of the set traveling mode is shown. Furthermore, in  FIG.  8   , an example of the notification image IM according to the degree of execution of the driving assistance (the amount of intervention of the traveling control for the driving assistance) is shown. In  FIG.  8   , an example of the notification image IM in which the first graphic F 1  included within the image area Ia of the notification image IM is assumed not to be deformed (i.e., is assumed to remain as a circle) and attention is paid to a part of the second graphic F 2  included within the image area Ia is shown. 
     When the driving control determiner  180  determines that the driver&#39;s motivation is level 7, the degree of execution of driving assistance is not changed because the ADAS function is turned “off” by the driver. In other words, the amounts of intervention of ACC, LSF, LKAS, and RDM are not set. The driving control determiner  180  enables the traveling mode to be changed by the driver. When the driver&#39;s motivation is level 7, the notification image generator  192  does not display the circle of the second graphic F 2  within the image area Ia such that a notification indicating that the traveling control based on the driving assistance is not executed is provided. 
     When it is determined that the driver&#39;s motivation is level 6, the driving control determiner  180  sets the degree of execution of driving assistance as a lowest degree. More specifically, the driving control determiner  180  sets the inter-vehicle distance from the preceding vehicle as the amounts of intervention of ACC and LSF as a shortest distance (“shortest”). The driving control determiner  180  sets LKAS such that LKAS is not executed (or is stopped) and sets RDM to be executed. In other words, the driving control determiner  180  performs a setting process such that only RDM is executed as the lateral system assistance. The driving control determiner  180  changes the traveling mode to the sport traveling mode. When the driver&#39;s motivation is level 6, the notification image generator  192  increases a distance between the first graphic F 1  and the second graphic F 2  and makes the circle of the second graphic F 2  thin such that a notification indicating that the traveling control based on the driving assistance is executed, but the degree of execution is low (the amount of intervention is small) is provided. That is, the notification image generator  192  increases the difference between the length of the diameter of the circle of the first graphic F 1  and the length of the diameter of the inner circle of the second graphic F 2  and decreases the difference between the length of the diameter of the inner circle of the second graphic F 2  and the length of the diameter of the outer circle. Furthermore, the notification image generator  192  lowers the degree of definition of the second graphic F 2 , i.e., makes the display of the circle of the second graphic F 2  lighter and less visible. 
     When it is determined that the driver&#39;s motivation is level 5, the driving control determiner  180  sets the degree of execution of driving assistance as a higher degree than when the driver&#39;s motivation is level 6. More specifically, the driving control determiner  180  sets the inter-vehicle distance from the preceding vehicle in ACC and LSF as a short distance (“short”). The driving control determiner  180  stops LKAS and sets only RDM to be executed as in the case where the driver&#39;s motivation is level 6. The driving control determiner  180  changes the traveling mode to the normal traveling mode. When the driver&#39;s motivation is level 5, the notification image generator  192  increases a distance between the first graphic F 1  and the second graphic F 2  and makes the circle of the second graphic F 2  thin as in the case where the driver&#39;s motivation is level 6 such that a notification indicating that the degree of execution of traveling control based on driving assistance is low (the amount of intervention is small), but is not as low as (is not as small as) that when the driver&#39;s motivation is level 6 is provided. However, the notification image generator  192  does not lower the degree of definition of the second graphic F 2 . 
     When it is determined that the driver&#39;s motivation is level 4, the driving control determiner  180  makes the degree of execution of driving assistance higher than when the driver&#39;s motivation is level 5. More specifically, the driving control determiner  180  sets the inter-vehicle distance from the preceding vehicle in ACC and LSF as a medium distance (“medium”). The driving control determiner  180  performs a setting process such that LKAS is executed with a reduced amount of intervention (the threshold value=“small”) thereof and sets RDM to be executed. In other words, the driving control determiner  180  performs a setting process such that the amount of intervention is small but both LKAS and RDM are executed as the lateral system assistance. The driving control determiner  180  changes the traveling mode to the normal traveling mode as in the case where the driver&#39;s motivation is level 5. When the driver&#39;s motivation is level 4, the notification image generator  192  makes the distance between the first graphic F 1  and the second graphic F 2  shorter than when the driver&#39;s motivation is level 5 and makes the circle of the second graphic F 2  slightly thick such that a notification indicating that the degree of execution of traveling control based on the driving assistance is higher than when the driver&#39;s motivation is level 5 is provided. In other words, the notification image generator  192  makes the second graphic F 2  close to the first graphic F 1  and increases the difference between the length of the diameter of the inner circle and the length of the diameter of the outer circle of the second graphic F 2  by decreasing the difference between the length of the diameter of the circle of the first graphic F 1  and the length of the diameter of the inner circle of the second graphic F 2  compared with the case where the driver&#39;s motivation is level 5. 
     When it is determined that the driver&#39;s motivation is level 3, the driving control determiner  180  makes the degree of execution of driving assistance higher than when the driver&#39;s motivation is level 4. More specifically, the driving control determiner  180  sets the inter-vehicle distance from the preceding vehicle in ACC and LSF as a long distance (“long”). The driving control determiner  180  sets LKAS such that LKAS is executed with the threshold value=“small” and sets RDM to be executed as in the case where the driver&#39;s motivation is level 4. The driving control determiner  180  changes the traveling mode to the comfort traveling mode. When the driver&#39;s motivation is level 3, the notification image generator  192  makes the distance between the first graphic F 1  and the second graphic F 2  shorter than when the driver&#39;s motivation is level 4 and makes the circle of the second graphic F 2  thicker such that a notification indicating that the degree of execution of traveling control based on the driving assistance is higher than when the driver&#39;s motivation is level 4 is provided. In other words, the notification image generator  192  makes the second graphic F 2  closer to the first graphic F 1  and further increases the difference between the length of the diameter of the inner circle and the length of the diameter of the outer circle of the second graphic F 2  by decreasing the difference between the length of the diameter of the circle of the first graphic F 1  and the length of the diameter of the inner circle of the second graphic F 2  compared with the case where the driver&#39;s motivation is level 4. 
     When it is determined that the driver&#39;s motivation is level 2, the driving control determiner  180  makes the degree of execution of driving assistance higher than when the driver&#39;s motivation is level 3. More specifically, the driving control determiner  180  sets the inter-vehicle distance from the preceding vehicle in ACC and LSF as the inter-vehicle distance=“long” as in the case where the driver&#39;s motivation is level 3. The driving control determiner  180  performs a setting process (the threshold value=“large”) such that LKAS is executed by increasing the amount of intervention of LKAS and sets the RDM to be executed. That is, the driving control determiner  180  performs a setting process such that both LKAS and RDM whose amounts of intervention are large are executed as lateral system assistance. The driving control determiner  180  may cause the degree of execution (the amount of intervention) of driving assistance when it is determined that the driver&#39;s motivation is level 2 to be the same as the degree of execution (the amount of intervention) of driving assistance when it is determined that the driver&#39;s motivation is level 3. The driving control determiner  180  changes the traveling mode to the comfort traveling mode as in the case where the driver&#39;s motivation is level 3. When the driver&#39;s motivation is level 2, the notification image generator  192  makes the distance between the first graphic F 1  and the second graphic F 2  shorter than when the driver&#39;s motivation is level 3 and makes the circle of the second graphic F 2  thicker such that a notification indicating that the degree of execution of traveling control based on the driving assistance is higher than when the driver&#39;s motivation is level 3 is provided. In other words, the notification image generator  192  makes the second graphic F 2  closer to the first graphic F 1  and further increases the difference between the length of the diameter of the inner circle and the length of the diameter of the outer circle of the second graphic F 2  by decreasing the difference between the length of the diameter of the circle of the first graphic F 1  and the length of the diameter of the inner circle of the second graphic F 2  compared with the case where the driver&#39;s motivation is level 3. 
     When it is determined that the driver&#39;s motivation is level 1, the driving control determiner  180  makes the degree of execution of driving assistance higher than when the driver&#39;s motivation is level 2 (or sets the degree of execution of driving assistance as a highest degree). That is, the driving control determiner  180  is in a state in which any driving control for driving assistance is not limited. More specifically, the driving control determiner  180  sets the inter-vehicle distance from the preceding vehicle in ACC and LSF as a longest distance (“longest”). The driving control determiner  180  sets LKAS such that LKAS is executed with the threshold value=“large” and sets RDM to be executed as in the case where the driver&#39;s motivation is level 2. The driving control determiner  180  changes the traveling mode to the comfort traveling mode as in the case where the driver&#39;s motivation is level 3 or the driver&#39;s motivation is level 2. When the driver&#39;s motivation is level 1, the notification image generator  192  makes the distance between the first graphic F 1  and the second graphic F 2  shortest and makes the circle of the second graphic F 2  thickest such that a notification indicating that the degree of execution of traveling control based on the driving assistance is highest is provided. In other words, the notification image generator  192  makes the second graphic F 2  closest to the first graphic F 1  and makes the difference between the length of the diameter of the inner circle and the length of the diameter of the outer circle of the second graphic F 2  largest by decreasing the difference between the length of the diameter of the circle of the first graphic F 1  and the length of the diameter of the inner circle of the second graphic F 2  compared with the case where the driver&#39;s motivation is level 2. 
     In this way, the notification image generator  192  visually notifies the driver of the presence or absence of execution and/or the high degree of execution of the traveling control based on the driving assistance (the large amount of intervention of traveling control of driving assistance) that has been determined on according to a combination of the distance between the first graphic F 1  and the second graphic F 2 , the thickness of the second graphic F 2 , and the like. More specifically, the notification image generator  192  changes the first graphic F 1  and the second graphic F 2  closer to each other as the degree of execution of driving assistance increases. Furthermore, the notification image generator  192  enables the second graphic F 2  to be viewed easily by increasing the thickness of the second graphic F 2  and increasing the degree of definition of the second graphic F 2  (darkening the display of the circle of the second graphic F 2 ) as the degree of execution of driving assistance increases. 
     [Example of Process of Determining Driver&#39;s Motivation] 
       FIG.  9    is a flowchart showing an example of a flow of a process of determining the driver&#39;s motivation executed by the driving control determiner  180 . The process of the present flowchart is iteratively executed, for example, while the vehicle control device  100  is operating. In the following description, it is assumed that the second recognizer  142  recognizes the driver&#39;s gripping state of the steering wheel  82  and the driver&#39;s visual line direction all the time. 
     First, the driving control determiner  180  determines whether or not ADAS have been turned “on” (step S 100 ). When ADAS have not been turned “on” in step S 100 , i.e., when ADAS have been turned “off,” the driving control determiner  180  determines that the driver&#39;s motivation is level 7 (step S 102 ). Subsequently, the driving control determiner  180  moves the process to step S 130 . 
     On the other hand, when ADAS have been turned “on” in step S 100 , the driving control determiner  180  acquires information about the driver&#39;s visual line direction recognized by the second recognizer  142  (step S 104 ). Subsequently, the driving control determiner  180  determines whether or not the visual line direction is the “front” (step S 106 ). When the visual line direction is not the “front” in step S 106 , the driving control determiner  180  determines that the driver&#39;s motivation is level 1 if the driving mode is mode A (step S 108 ). Subsequently, the driving control determiner  180  moves the process to step S 130 . 
     On the other hand, when the visual line direction is the “front” in step S 106 , the driving control determiner  180  acquires information about the driver&#39;s gripping state of the steering wheel  82  recognized by the second recognizer  142  (step S 110 ). Subsequently, the driving control determiner  180  determines whether or not the presence or absence of gripping=“presence” is satisfied in the acquired gripping state (step S 112 ). When the presence or absence of gripping=“presence” is not satisfied in step S 112 , the driving control determiner  180  determines that the driver&#39;s motivation is level 2 (step S 114 ). Subsequently, the driving control determiner  180  moves the process to step S 130 . 
     On the other hand, when the presence or absence of gripping=“presence” is satisfied in step S 112 , the driving control determiner  180  determines whether or not the number of grips=“2” is satisfied in the acquired gripping state (step S 116 ). When the number of grips=“2” is not satisfied in step S 116 , the driving control determiner  180  determines whether or not the gripping position=“right or left” is satisfied in the acquired gripping state (step S 118 ). When the gripping position=“right or left” is not satisfied in step S 118 , the driving control determiner  180  determines that the driver&#39;s motivation is level 3 (step S 120 ). Subsequently, the driving control determiner  180  moves the process to step S 130 . When the gripping position=“right or left” is satisfied in step S 118 , the driving control determiner  180  determines that the driver&#39;s motivation is level 4 (step S 122 ). Subsequently, the driving control determiner  180  moves the process to step S 130 . 
     On the other hand, when the number of grips=“2” is satisfied in step S 116 , the driving control determiner  180  determines whether or not the gripping position=“left/right” is satisfied in the acquired gripping state (step S 124 ). When it is determined that the gripping position=“left/right” is not satisfied in step S 124 , the driving control determiner  180  determines that the driver&#39;s motivation is level 5 (step S 126 ). Subsequently, the driving control determiner  180  moves the process to step S 130 . When the gripping position=“right/left” is satisfied in step S 124 , the driving control determiner  180  determines that the driver&#39;s motivation is level 6 (step S 128 ). Subsequently, the driving control determiner  180  moves the process to step S 130 . 
     Through this process, the driving control determiner  180  determines the driver&#39;s current motivation on the basis of the gripping state of the steering wheel  82  and the visual line direction of the driver recognized by the second recognizer  142 . 
     Subsequently, the driving control determiner  180  determines on the degree of execution of driving assistance (the amount of intervention of traveling control of driving assistance) on the basis of a level of the determined motivation of the driver and determines on each function of driving assistance included in ADAS (ACC and LSF of the longitudinal system assistance and LKAS and RDM of the lateral system assistance in  FIG.  8   ) and the traveling mode. The driving control determiner  180  sets the determined degree of assistance and the determined traveling mode in components for executing the functions. Thereby, the driving assistance executor  144  executes traveling control based on the driving assistance on the basis of the degree of assistance determined on by the driving control determiner  180  (step S 130 ). 
     The notification image generator  192  generates a notification image IM on the basis of the driver&#39;s gripping state of the steering wheel  82  recognized by the second recognizer  142 , the driver&#39;s motivation determined by the driving control determiner  180 , and the presence or absence of traveling control and/or the degree of execution of the traveling control in the driving assistance determined on by the driving control determiner  180  (step S 132 ). In other words, the notification image generator  192  generates the notification image IM indicating the traveling control based on the driving assistance executed by the driving assistance executor  144 . The notification image generator  192  causes the display device  32  to display the generated notification image IM (step S 134 ). Thereby, the driver can visually recognize the content of the traveling control of the driving assistance being executed in the host vehicle M from the notification image IM displayed on the display device  32 . 
     The vehicle control device  100  returns the process to step S 100 . 
     Through this process, the driving control determiner  180  changes the driving assistance and the traveling mode of the host vehicle M to the suitable driving assistance and traveling mode corresponding to the determined current motivation of the driver. Thereby, the vehicle control device  100  can cause the host vehicle M to travel in accordance with the driver&#39;s motivation and appropriately provide driving assistance to the driver. Furthermore, the vehicle system  1  can notify the driver of the gripping state of the steering wheel  82  or the degree of execution of the traveling control based on driving assistance using the notification image IM displayed on the display device  32 . Thereby, the driver can drive the host vehicle M after visually recognizing the current traveling state of the host vehicle M. 
     Meanwhile, it is also conceivable that the driver intentionally drives the host vehicle M while the host vehicle M is performing traveling control based on driving assistance. For example, it is also conceivable that the driving control determiner  180  determines that the driver&#39;s motivation is level 4 and the driver changes the traveling lane in which the host vehicle M is traveling by performing a steering operation on the steering wheel  82  when the host vehicle M is traveling in a state in which the driving assistance executor  144  is executing LKAS (threshold value=“low”) and RDM. The notification image generator  192  can also visually notify the driver of such a change in the traveling state of the host vehicle M. 
       FIG.  10    is a diagram showing an example of a notification image IM when a notification of a change in the traveling state of the host vehicle M is provided. In  FIG.  10   , it is assumed the notification image IM has the configuration shown in  FIG.  3    (here, for example, information of a speedometer, a tachometer, or the like is not displayed within the image area Ia) and an example of a notification image IM (hereinafter referred to as a “notification image IM- 1 ”) when the driver performs the steering operation on the steering wheel  82  and hence is about to change the traveling lane of the host vehicle M to the right if the driver&#39;s motivation is level 4 is shown. 
     When the driver&#39;s motivation is level 4, the driving assistance executor  144  executes traveling control of driving assistance based on LKAS and RDM (see  FIG.  8   ). In other words, the driving assistance executor  144  executes traveling control such that the host vehicle M is allowed to travel in a straight direction using the function of LKAS. At this time, when the driver turns the steering wheel  82  to the right in a steering operation and the host vehicle M deviates from the current traveling lane, the driving assistance executor  144  performs an operation such that the steering wheel  82  performs a steering operation in a direction in which the traveling lane of the host vehicle M is returned to a current traveling lane using the function of RDM. In other words, the driving assistance executor  144  causes the steering wheel  82  to generate a force (a so-called reaction force) that repels the steering operation of the driver. At this time, the notification image generator  192  generates the notification image IM- 1  including the second graphic F 2  indicating that the traveling control of driving assistance is activated with respect to the driver&#39;s steering operation and causes the display device  32  to display the notification image IM- 1 . More specifically, the notification image generator  192  generates the notification image IM- 1  in which the second graphic F 2 - 2  corresponding to a direction in which the driver is performing the steering operation, i.e., a direction in which the reaction force is generated, is highlighted and causes the display device  32  to display the notification image IM- 1 . The method in which the second graphic F 2 - 2  is highlighted may be based on any method such as blinking the arc of the second graphic F 2 - 2 . Thereby, the driver can perform a steering operation on the steering wheel  82  to return the traveling lane of the host vehicle M if the driver is not intentionally trying to change the traveling lane by visually recognizing the second graphic F 2 - 2  highlighted in the notification image IM- 1 . 
     On the other hand, when the driver is intentionally trying to change the traveling lane of the host vehicle M, the driver continues the steering operation on the steering wheel  82 . In this case, the driving assistance executor  144  allows the driver to change the traveling lane by stopping the generation of the reaction force based on the RDM function. At this time, the notification image generator  192  generates the notification image IM- 1  including the second graphic F 2  shown to prompt the driver to pay attention to the steering operation and causes the display device  32  to display the notification image IM- 1 . A method in which the driver is prompted to pay attention to the steering operation through the second graphic F 2  may be based on any method. For example, the notification image generator  192  may indicate that it is necessary for the driver to pay attention to the direction of the second graphic F 2 - 2 , i.e., the right, by changing the color of the arc of the second graphic F 2 - 2  corresponding to the direction in which the driver is performing the steering operation to, for example, “red” that is easily recognized by the driver (and blinking the arc of the second graphic F 2 - 2 ). In  FIG.  10   , an example of a state in which the color of the arc of the second graphic F 2 - 2  is “red” and the second graphic F 2 - 2  is blinking in the notification image IM- 1  is shown. Thereby, the driver can make the intended lane change while paying attention to a situation of a right traveling lane (a traveling state of another vehicle or the like) to which he or she is prompted to pay attention by visually recognizing the second graphic F 2 - 2  within the notification image IM- 1 . 
     As described above, the vehicle system  1  can prompt the driver to pay attention to the lane change of the host vehicle M by the driver through vision (the notification image IM- 1 ) and tactile (the reaction force generated by the steering wheel  82 ). 
     As described above, according to the vehicle control system of the embodiment, the automated driving controller  120  provided in the vehicle control device  100  performs traveling control related to the automated driving in the host vehicle M, the driving assistance controller  140  performs traveling control related to the driving assistance in the host vehicle M, and the traveling mode controller  160  performs traveling control related to the traveling mode in host vehicle M. In the vehicle control system of the embodiment, the driving control determiner  180  provided in the vehicle control device  100  determines on the driving mode of the automated driving, the degree of execution of the driving assistance, and the traveling mode in the host vehicle M in association with each type of traveling control. Thereby, in the vehicle control system of the embodiment, the host vehicle M is allowed to travel in the driving mode or the traveling mode that matches the driver&#39;s motivation for driving the host vehicle M, i.e., the driver&#39;s desire, and driving assistance can be provided for the driver appropriately in accordance with the driving state of the host vehicle M. 
     Furthermore, in the vehicle control system of the embodiment, the display processor  190  provided in the vehicle control device  100  generates a notification image based on the driver&#39;s gripping state of the steering wheel  82 , the determined motivation of the driver, and the presence or absence of execution of traveling control and/or the degree of execution of the traveling control in the determined driving assistance. In the vehicle control system of the embodiment, a notification is visually provided to the driver by causing the display device  32  to display the generated notification image. Thereby, in the vehicle control system of the embodiment, it is possible to easily notify the driver of the driver&#39;s motivation for driving the host vehicle M and the content of the traveling control of driving assistance being executed in the host vehicle M. 
     The embodiment described above can be represented as follows. 
     A vehicle control system including: 
     a hardware processor; and 
     a storage device storing a program, 
     wherein the hardware processor reads and executes the program stored in the storage device to: 
     receive a steering operation on a steering operation element of a vehicle by a driver; 
     detect a gripping state of the steering operation element by the driver of the vehicle; and 
     when a display device is allowed to display a notification image indicating at least the gripping state and including a first graphic deformable on the basis of a circle within an entire image area, cause the display device to display the notification image including the first graphic deformed to expand a location corresponding to a part where the driver is gripping the steering operation element. 
     In the embodiment, the case where driving assistance corresponding to the level of the driver&#39;s motivation is provided to the driver in the host vehicle M equipped with an automated driving function and the driver is visually notified of the content of the traveling control of the driving assistance being executed in the host vehicle M through the notification image IM has been described. However, the function of providing the driver with driving assistance according to the level of the driver&#39;s motivation and the function of visually notifying the driver of the content of the traveling control of driving assistance through the notification image IM can be provided to the driver even in the vehicle in which the automated driving function is not provided. That is, in the vehicle control device  100 , even if the automated driving controller  120  is omitted, the function of providing the driver with driving assistance corresponding to the level of the driver&#39;s motivation and the function of visually notifying the driver of the content of the traveling control of the driving assistance through the notification image IM can be implemented. In relation to the configuration and process of the vehicle control device in this case, the determination of level 1 of the driver&#39;s motivation is omitted only in the driving control determiner  180  of the embodiment and it is only necessary for the other configuration and process to be equivalent to the configuration and process of the vehicle control device  100  of the embodiment. Therefore, even in a vehicle in which the automated driving controller  120  is omitted, the function of notifying the driver of the content of the traveling control of driving assistance is similar to that in the configuration and process in the vehicle control device  100  of the embodiment. 
     In the embodiment, the gripping state of the steering wheel  82 , i.e., the combination of the gripping position and the number of grips, and the driver&#39;s visual line direction are used to determine the driver&#39;s motivation for driving. However, the information used to determine the driver&#39;s motivation is not limited to these items. For example, information about the strength with which the driver grips the steering wheel  82  may be further added as the gripping state of the steering wheel  82 . In this case, the motivation level of the driver may be determined on the basis of the strength with which the driver grips the steering wheel  82  as in the embodiment or the motivation level of the driver may be determined to be divided into more levels. Because it is possible to similarly conceive the configuration and process of the vehicle control device (the configuration and process related to the generation of the notification image IM) in this case on the basis of the configuration and process of the vehicle control device  100  of the embodiment, the description of the determination of the level of the driver&#39;s motivation including the strength of the gripping of the steering wheel  82  is omitted. 
     Although modes for carrying out the present invention have been described using embodiments, the present invention is not limited to the embodiments and various modifications and substitutions can also be made without departing from the scope and spirit of the present invention.