Autonomous driving control device and autonomous driving control method

Abstract

An autonomous driving ECU (50) functions as an autonomous driving control device for controlling the traveling of a host vehicle (Am). The autonomous driving ECU (50) acquires road type information indicating whether a road that is a travel route for the host vehicle (Am) is a high-speed road (KD) or a general road (ID), and changes the automation level of the travel control carried out by an autonomous driving function in accordance with the road type. When a travel route from a high-speed road (KD) to a general road (ID) is set, the autonomous driving ECU (50) allows continuation of travel control at the same automation level as the high-speed road (KD) until the host vehicle (Am) reaches a stop point (PsE) where the vehicle first stops on the general road (ID) even after the host vehicle (Am) has passed through an exit gate (GtE) of the high-speed road (KD).

Description

Automatic driving control device and automatic driving control method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-44319 filed in Japan on March 20, 2024, the contents of which are incorporated by reference in their entirety.

[0002] The disclosure of this specification relates to an automatic driving control technology for controlling the driving of a vehicle.

[0003] Patent Literature 1 discloses an automatic driving control unit that controls a vehicle to travel along a route to a destination. When the vehicle passes through a gate that marks an exit from an expressway to a general road, the automatic driving control unit either continues automatic driving or switches from automatic driving to manual driving before the gate.

[0004] Patent No. 6692935

[0005] Generally, the level of automation of automated driving that can be implemented on expressways is higher than the level of automation that can be implemented on general roads. Therefore, if a vehicle passes through an exit gate on a highway while continuing automated driving without switching to manual driving before the gate, it is necessary to switch to an automation level that is appropriate for general roads. However, Patent Document 1 does not disclose switching the automation level after passing through the exit gate. As a result, there is a risk that driving control at an inappropriate automation level will continue even after passing through the exit gate.

[0006] The present disclosure aims to provide an automatic driving control device and an automatic driving control method that can appropriately continue driving control using the automatic driving function even after passing through an exit gate.

[0007] In order to achieve the above-mentioned object, one disclosed aspect is an automatic driving control device that controls the driving of a vehicle using an automatic driving function, and is equipped with a road information acquisition unit that acquires information on the road type, indicating whether the road that will be the driving route of the vehicle is an expressway or a general road, and a control change unit that changes the automation level of driving control by the automatic driving function according to the road type, and when a driving route from an expressway to a general road is set, the control change unit is an automatic driving control device that allows driving control to continue at the same automation level as on an expressway, even after the vehicle has passed the exit gate of the expressway, until the vehicle reaches the stopping point where it will first stop.

[0008] Another disclosed aspect is an autonomous driving control method for controlling the driving of a vehicle using an autonomous driving function, which includes, in processing performed by at least one processing unit, the steps of: acquiring road type information indicating whether the road along which the vehicle will travel is an expressway or a general road; changing the automation level of driving control by the autonomous driving function according to the road type; and, when a driving route from an expressway to a general road is set, allowing driving control to continue at the same automation level as on the expressway, even after the vehicle has passed through the exit gate of the expressway, until the vehicle reaches the stopping point where it will first stop.

[0009] In these aspects, even after passing through an exit gate on a highway, driving control can be continued at the same automation level as on the highway until the stopping point where the vehicle is forced to temporarily stop. Then, in the section of a general road beyond the stopping point, driving control can be implemented at an automation level corresponding to that of a general road. As a result, driving control by the automated driving function can be continued appropriately even after passing through an exit gate.

[0010] It should be noted that the reference numbers in parentheses in the claims merely indicate an example of the correspondence with the specific configurations in the embodiments described below, and do not limit the technical scope in any way. Furthermore, claims not explicitly stated in the claims may be combined together if no particular problems arise in the combination.

[0011] 1 is a diagram showing an overall view of an in-vehicle system including an autonomous driving ECU according to a first embodiment of the present disclosure; FIG. 2 is a block diagram showing details of the autonomous driving ECU together with related configurations; FIG. 3 is a diagram showing an example of a road on which an exit gate is provided; FIG. 4 is a diagram showing transitions in automation levels in a plurality of cases in which a driving route from an expressway to a general road is set; FIG. 5 is a flowchart showing details of the automation level control process performed by the autonomous driving ECU together with FIG. 6; FIG. 6 is a flowchart showing details of the automation level control process together with FIG. 5; FIG. 7 is a flowchart showing details of the automation level control process of a second embodiment together with FIG. 6; FIG. 8 is a diagram showing transitions in automation levels allowed on a driving route from an expressway to a general road in pattern 1 of a third embodiment; FIG. 9 is a diagram showing transitions in automation levels allowed on a driving route from an expressway to a general road in pattern 2 of the third embodiment;

[0012] Hereinafter, several embodiments will be described with reference to the drawings. Note that corresponding components in each embodiment are given the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment described previously can be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can also be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0013] (First embodiment) The functions of an automatic driving control device according to a first embodiment of the present disclosure are realized by an automatic driving ECU (Electronic Control Unit) 50 shown in Figures 1 and 2. The automatic driving ECU 50 is mounted on a vehicle (hereinafter, host vehicle Am). By mounting the automatic driving ECU 50, the host vehicle Am becomes an automatic driving vehicle or an autonomously traveling vehicle equipped with an automatic driving function, and is able to travel using the automatic driving function.

[0014] The autonomous driving ECU 50 is an in-vehicle ECU that realizes an autonomous driving function that can take over driving operations from the driver. The autonomous driving ECU 50 can perform advanced driving assistance or partial autonomous driving at around level 2, and autonomous driving at level 3 or higher where the system is the main control element. The autonomous driving levels in this disclosure are based on standards defined by the Society of Automotive Engineers.

[0015] Level 2 autonomous driving is eyes-on autonomous driving, which requires the driver to visually monitor the area around the vehicle. Level 2 autonomous driving (driving control) includes hands-on autonomous driving, in which the driver is required to hold the steering wheel (hereinafter referred to as the steering wheel), and hands-off autonomous driving, in which the driver is not required to hold the steering wheel.

[0016] Level 3 autonomous driving (driving control) is eyes-off autonomous driving, which means that there is no need to monitor the surroundings of the vehicle and no obligation to monitor the surroundings. The autonomous driving ECU 50 may be capable of Level 4 fully autonomous driving, in which the system performs all driving tasks under certain conditions, and Level 5 fully autonomous driving, in which the system performs all driving tasks under all conditions. Level 4 autonomous driving is brain-off autonomous driving, in which there is essentially no request for the driver to take over driving. Level 5 autonomous driving is driverless autonomous driving, which does not require a driver on board.

[0017] The autonomous driving ECU 50 switches the control state of the autonomous driving function among a plurality of control states, including at least autonomous driving control with a periphery monitoring obligation of Level 2 or lower, and autonomous driving control without a periphery monitoring obligation of Level 3 or higher. In the following description, autonomous driving control of Level 2 or lower will be referred to as "driving assistance control," and autonomous driving control of Level 3 or higher will be referred to as "autonomous driving control." Furthermore, driving control at autonomous driving Level 0 means that the autonomous driving function is stopped, and is equivalent to manual driving.

[0018] [Configuration of the In-Vehicle System] The autonomous driving ECU 50 is included in an in-vehicle system mounted on the host vehicle Am. The autonomous driving ECU 50 is communicatively connected to a communication bus 99 of an in-vehicle network 1 that constitutes the in-vehicle system. The communication bus 99 is connected to a periphery monitoring sensor 30, a locator 35, a navigation ECU 38, an in-vehicle communication device 39, a cruise control ECU 40, an HMI (Human Machine Interface) control device 100, and the like. These nodes connected to the communication bus 99 can communicate with each other. Certain nodes among these ECUs, etc. may be directly electrically connected to each other and be able to communicate without going through the communication bus 99.

[0019] The perimeter monitoring sensor 30 is an autonomous sensor mounted on the host vehicle Am and monitors the environment surrounding the host vehicle Am. The perimeter monitoring sensor 30 is capable of detecting moving and stationary objects within a detection range around the host vehicle. The perimeter monitoring sensor 30 provides detection information of objects around the host vehicle to the autonomous driving ECU 50, etc. The perimeter monitoring sensor 30 includes a camera unit 31, a millimeter-wave radar 32, a lidar 33, and an exterior acoustic sensor 34. The perimeter monitoring sensor 30 may further include a sonar sensor, etc.

[0020] The camera unit 31 includes a front camera module, a rear camera module, a left side camera module, and a right side camera module. The camera unit 31 includes multiple camera modules, so that it can capture images of the entire surroundings of the vehicle Am. The camera unit 31 provides the autonomous driving ECU 50 with image data captured by each camera module or analysis information of the image data as detection information.

[0021] The millimeter-wave radar 32 emits millimeter waves or quasi-millimeter waves toward the surroundings of the vehicle. The millimeter-wave radar 32 receives reflected waves from moving objects, stationary objects, and the like, and generates detection information, which is then provided to the autonomous driving ECU 50.

[0022] The lidar 33 emits laser light toward the surroundings of the vehicle. The lidar 33 receives the laser light reflected by moving objects and stationary objects within the irradiation range, and generates detection information (point cloud data) that is then provided to the autonomous driving ECU 50.

[0023] The exterior acoustic sensor 34 is mainly composed of a microphone element that converts sound into an electrical signal. The exterior acoustic sensor 34 is held on the exterior structure of the host vehicle Am with the sound collection surface of the microphone element facing the exterior structure. Multiple exterior acoustic sensors 34 are provided on the front, rear, left and right sides, ceiling, etc. of the host vehicle Am. The exterior acoustic sensors 34 are capable of detecting incoming sounds coming from all around the host vehicle Am and collect environmental sounds around the host vehicle Am. The exterior acoustic sensors 34 provide the autonomous driving ECU 50 with sound data of the environmental sounds generated by each microphone element or analysis information of the sound data as detection information.

[0024] The locator 35 includes a GNSS (Global Navigation Satellite System) receiver, an inertial sensor, etc. The locator 35 sequentially determines the position and traveling direction of the host vehicle Am by combining positioning signals received from multiple positioning satellites by the GNSS receiver, measurement results from the inertial sensor, and vehicle speed information output to the communication bus 99. The locator 35 sequentially outputs position information and direction information of the host vehicle Am based on the positioning results to the communication bus 99 as locator information.

[0025] The locator 35 also has a map database that stores map data. The map database is primarily composed of a large-capacity storage medium that stores a large amount of three-dimensional map data and two-dimensional map data. The three-dimensional map data is a so-called high-definition (HD) map and includes road information necessary for autonomous driving. Specifically, the three-dimensional map data includes three-dimensional road shape information and detailed information about each lane. The locator 35 can update the three-dimensional map data and two-dimensional map data to the latest information through external communication via the on-board communication device 39. The locator 35 reads map data about the area around the current location from the map database and provides it to the autonomous driving ECU 50, the HMI control device 100, etc., along with locator information.

[0026] The navigation ECU 38 acquires information about a destination specified by a passenger such as a driver based on operation information acquired from the HMI control device 100. The navigation ECU 38 acquires vehicle position information and direction information from the locator 35, and sets a route from the current position to the destination. The navigation ECU 38 provides route information indicating the set route to the destination to the autonomous driving ECU 50, the HMI control device 100, etc. The navigation ECU 38 works in cooperation with the HMI control device 100 to provide route guidance to the destination by combining screen displays and voice messages, etc., and notifying the driver of the direction of travel of the vehicle Am at intersections, branching points, etc.

[0027] Here, a user terminal such as a smartphone or tablet may be connected to the in-vehicle network 1 or the HMI control device 100. Such a user terminal may provide the autonomous driving ECU 50 with information such as vehicle position information, direction information, and map data, instead of the locator 35. Furthermore, the user terminal may provide the autonomous driving ECU 50 and the HMI control device 100 with information such as route information to a destination, instead of the navigation ECU 38.

[0028] The in-vehicle communication device 39 is an external communication unit mounted on the host vehicle Am. The in-vehicle communication device 39 functions as a V2X (Vehicle to Everything) communication device. The in-vehicle communication device 39 transmits and receives information via wireless communication between roadside devices installed on the side of the road and at toll booths TG (see FIG. 3 ), and other vehicles around the host vehicle. As an example, the in-vehicle communication device 39 receives congestion information and traffic regulation information around the current location of the host vehicle Am and in the direction of travel from the roadside devices. The congestion information and traffic regulation information are, for example, VICS (registered trademark) information. The in-vehicle communication device 39 provides the received congestion information and traffic regulation information to the autonomous driving ECU 50, the HMI control device 100, etc.

[0029] The cruise control ECU 40 is an electronic control device that mainly includes a microcontroller. The cruise control ECU 40 generates vehicle speed information indicating the current traveling speed of the host vehicle Am based on detection signals from wheel speed sensors provided at the hub portions of each wheel, and sequentially outputs the generated vehicle speed information to the communication bus 99. The cruise control ECU 40 has at least the functions of a brake control ECU, a drive control ECU, and a steering control ECU. The cruise control ECU 40 continuously controls the braking force of each wheel, the output of the on-board power source, and the steering angle based on operation commands based on the driver's driving operation or control commands from the automatic driving ECU 50.

[0030] The HMI control device 100, together with a plurality of display devices, an audio device 24, an ambient light 25, an operation device 26, etc., constitutes an HMI system 10. The HMI system 10 has an input interface function that accepts operations by an occupant such as a driver of the host vehicle Am, and an output interface function that presents information to the driver.

[0031] The display devices present information to the driver's vision by displaying images, etc. The display devices include a meter display 21, a center information display (hereinafter referred to as CID) 22, and a head-up display (hereinafter referred to as HUD) 23. The CID 22 has a touch panel function and detects touch operations on the display screen by the driver, etc.

[0032] The audio system 24 has multiple speakers installed in the vehicle cabin surrounding the driver's seat, and reproduces alarm sounds, voice messages, etc. through the speakers. The ambient lights 25 are provided on the instrument panel, steering wheel, etc. The ambient lights 25 present information using the driver's peripheral vision by changing the color of the emitted light.

[0033] The operation device 26 is an input unit that accepts user operations by the driver, etc. User operations related to activation and deactivation of the autonomous driving function, user operations related to setting a destination for route guidance, etc. are input to the operation device 26. The operation device 26 includes a steering switch provided on the spokes of the steering wheel, an operation lever provided on the steering column, and a voice input device that recognizes what the driver is saying.

[0034] The HMI control device 100 is a computer mainly including a processing unit 11, a RAM 12, a storage unit 13, an input / output interface 14, and a control circuit equipped with a bus connecting these units. The processing unit 11 accesses the RAM 12 to execute various processes (instructions) for implementing the presentation control method according to the present disclosure. The storage unit 13 stores various programs (presentation control programs, etc.) executed by the processing unit 11. The HMI control device 100 functions as a presentation control device and comprehensively controls information presentation using multiple display devices, an audio device 24, and ambient light 25.

[0035] The HMI control device 100 presents information related to autonomous driving in cooperation with the autonomous driving ECU 50. The HMI control device 100 acquires control status information indicating the operating status of the autonomous driving function and a request to present information related to the autonomous driving function from the autonomous driving ECU 50. The HMI control device 100 provides content and presents information according to the operating status of the autonomous driving based on the control status information and the implementation request. For example, when the autonomous driving ECU 50 plans to end autonomous driving control, the HMI control device 100 issues a notification requesting the implementation of a driving operation, in other words, a notification requesting a driver change.

[0036] The HMI control device 100 acquires operation information indicating the content of a user operation from the CID 22, the operation device 26, etc. The HMI control device 100 provides operation information of a user operation related to the autonomous driving function to the autonomous driving ECU 50. The HMI control device 100 provides operation information of a user operation for setting a destination of the host vehicle Am to the navigation ECU 38.

[0037] [Configuration of Autonomous Driving ECU] The autonomous driving ECU 50 is a computer that mainly includes a processing unit 51, a RAM 52, a storage unit 53, an input / output interface 54, and a control circuit that includes a bus connecting these elements. The processing unit 51 accesses the RAM 52 to execute various processes (instructions) for implementing the autonomous driving control method according to the present disclosure. The storage unit 53 stores various programs (autonomous driving control programs, etc.) that are executed by the processing unit 51. As the processing unit 51 executes the programs, the autonomous driving ECU 50 is configured with an information linkage unit 61, an environment recognition unit 62, a behavior determination unit 63, a control execution unit 64, etc. as functional units for implementing the autonomous driving function.

[0038] The information linking unit 61 provides information to the HMI control device 100 and acquires information from the HMI control device 100. The information linking unit 61 enables the sharing of acquired information between the autonomous driving ECU 50 and the HMI control device 100. The information linking unit 61 provides the HMI control device 100 with control status information indicating the operating state of the autonomous driving function, and the recognition results of the surroundings of the vehicle by the environment recognition unit 62. The information linking unit 61 outputs a request to execute an alert to the HMI control device 100, thereby enabling the HMI system 10 to issue an alert that is synchronized with the operating state of the autonomous driving function. The information linking unit 61 acquires operation information related to autonomous driving from the HMI control device 100.

[0039] The environment recognition unit 62 recognizes the driving environment of the host vehicle Am by combining the locator information and map data acquired from the locator 35 with the detection information acquired from the perimeter monitoring sensor 30. The environment recognition unit 62 acquires route information from the navigation ECU 38 and provides the acquired route information to the behavior determination unit 63. The environment recognition unit 62 acquires, from the communication bus 99, information indicating the state of the host vehicle Am, such as vehicle speed information indicating the current driving speed. The environment recognition unit 62 has an other vehicle recognition unit 73 and a road recognition unit 74 as sub-functional units for recognizing the driving environment.

[0040] The other vehicle grasping unit 73 grasps the size, type, relative position, relative speed, etc. of dynamic targets around the host vehicle, such as other vehicles traveling around the host vehicle Am. For example, in a scene where the host vehicle Am passes through a toll gate TG (see FIG. 3 ), the other vehicle grasping unit 73 grasps the presence or absence of a vehicle traveling parallel to the host vehicle Am, and the size, type, relative position, relative speed, etc. of the recognized parallel vehicle. The other vehicle grasping unit 73 provides the behavior determination unit 63 with the recognition results related to other vehicles around the host vehicle.

[0041] The road recognition unit 74 acquires road information related to the roads on which the host vehicle Am is traveling and the roads on which the host vehicle Am is scheduled to travel, based on route information acquired from the navigation ECU 38. The road recognition unit 74 acquires road type information indicating whether the roads along the host vehicle Am's travel route are expressways (KD) or general roads (ID). For example, in a scene in which the host vehicle Am passes through a toll gate TG (see FIG. 3 ), the road recognition unit 74 acquires information indicating the road shapes of the sections before and after the toll gate TG before the host vehicle Am arrives at the toll gate TG. Detailed road information around the toll gate TG may be recorded in map data stored in a map database, or may be included in information received by the on-board communication device 39 from a roadside device. The road recognition unit 74 provides the acquired road information to the behavior determination unit 63.

[0042] When the autonomous driving ECU 50 has control of driving operations, the behavior determination unit 63 determines the behavior of the host vehicle Am based on the route information, road information, and recognition results of the driving environment acquired from the environment recognition unit 62. The behavior determination unit 63 generates a planned driving line along which the host vehicle Am will travel as a driving plan that defines the behavior of the host vehicle Am, and outputs the generated planned driving line to the control execution unit 64. The behavior determination unit 63 has a control switching unit 77 as a sub-functional unit.

[0043] The control switching unit 77 cooperates with the cruise control ECU 40 to switch the control state of the host vehicle Am between automatic driving and manual driving. The control switching unit 77 switches the automation level of cruise control (automatic driving control) performed by the automatic driving function. The automation level of cruise control is, in other words, the state of cruise control executed by the automatic driving function. For example, when the information linking unit 61 detects an input of an operation to transition to level 3 or level 4, the control switching unit 77 switches the automation level of cruise control from manual driving or driving assistance control of level 2 or lower to autonomous cruise control of level 3 or higher. When the control switching unit 77 determines to end the autonomous cruise control, it switches the cruise control state from autonomous cruise control to driving assistance control or manual driving.

[0044] When the autonomous driving ECU 50 has control of driving operations, the control execution unit 64 cooperates with the cruise control ECU 40 to execute acceleration / deceleration control, steering control, and the like of the host vehicle Am in accordance with the planned driving line generated by the action determination unit 63. Specifically, the control execution unit 64 generates control commands based on the planned driving line and sequentially outputs the generated control commands to the cruise control ECU 40.

[0045] [Autonomous driving control when heading from an expressway to a general road] In the autonomous driving ECU 50, the automation level of autonomous driving that can be performed on the expressway KD shown in Figures 3 and 4 is different from the automation level of autonomous driving that can be performed on the general road ID. Generally, autonomous driving control of autonomous driving level 3 (eyes-off autonomous driving) or higher is permitted on the expressway KD. In contrast, only driving assistance control of autonomous driving level 2 (eyes-on autonomous driving control and hands-on autonomous driving control) or lower is permitted on the general road ID. As described above, the automation level of autonomous driving that can be performed on the expressway KD is higher than the automation level of autonomous driving that can be performed on the general road ID.

[0046] Expressways (KD) are expressways and motorways that are off-limits to pedestrians, cyclists, and some small vehicles. General roads (ID) are roads other than expressways (KD). Between these expressways (KD) and general roads (ID), there are toll booths (TG) for collecting tolls for the expressways (KD).

[0047] The toll gate TG has multiple gates. Each gate is equipped with a roadside wireless device that communicates wirelessly with an ETC (Electronic Toll Collection, registered trademark) vehicle unit. The multiple gates include at least one entrance gate GtI and one exit gate GtE. The entrance gate GtI is a gate through which a vehicle passes when entering the expressway KD from the general road ID. The exit gate GtE is a gate through which a vehicle passes when exiting the expressway KD to the general road ID.

[0048] The road section immediately before entering the entrance gate GtI is a transition section CS where the road type changes from a general road ID to an expressway KD. Similarly, the road section immediately after passing through the exit gate GtE is a transition section CS where the road type changes from an expressway KD to a general road ID. The transition section CS is generally a single road. In addition, there are generally no pedestrians or other obstacles in the transition section CS. Therefore, it is technically possible to achieve the same level of automated driving control in the transition section CS as on the expressway KD.

[0049] Therefore, the autonomous driving ECU 50 (see FIG. 2) allows continuation of cruise control at the same automation level as on the expressway KD, at least in the transition section CS after passing through the exit gate GtE. Below, details of the control for changing or maintaining the automation level of cruise control in several cases when the vehicle Am's travel route is set on the transition section CS from the expressway KD to the general road ID will be described based on FIGS. 3 and 4, with reference to FIGS. 1 and 2.

[0050] <Details of Functions of Road Recognition Unit and Control Switching Unit> When a driving route from the expressway KD to an ordinary road ID is set by the navigation ECU 38, the road recognition unit 74 acquires road information around the toll gate TG, including the exit gate GtE. The road recognition unit 74 sets a transition section CS based on the acquired road information. The transition section CS is a road section between a gate point PgE where the exit gate GtE is located and a stop point PsE where the host vehicle Am first makes a temporary stop on the ordinary road ID.

[0051] The exit gate GtE may be located on the main roadway of the expressway KD, or on a ramp that branches off from the main roadway. When the exit gate GtE is located on the main roadway (see the center of Figure 3), the main road section HeS from the exit gate GtE to the rampway and the section of the ramp that branches off from this main road section HeS toward the general road ID (hereinafter referred to as the ramp section RkS) form the transition section CS. On the other hand, when the exit gate GtE is located on the rampway (see the lower left of Figure 3), the section of the rampway after the exit gate GtE (hereinafter referred to as the ramp section RiS) forms the transition section CS.

[0052] The stop point PsE is the point where a ramp way branching off from the expressway KD meets an ordinary road ID, and is a point on the near side of an intersection with a stop line. The stop point PsE is the end of the ramp sections RkS, RiS. The intersection where the stop point PsE is located may or may not be equipped with a traffic light. If the stop point PsE is set at an intersection with a traffic light and the traffic light is lit green, allowing progression, the vehicle Am does not have to stop at the stop point PsE. The stop point PsE may also be a temporary stop point where the vehicle waits to enter a merging section where the ramp way merges with an ordinary road ID.

[0053] The road recognition unit 74 recognizes the section length Lc of the transition section CS. The road recognition unit 74 compares the section length Lc with a threshold distance and determines whether the section length Lc exceeds the threshold distance. The threshold distance is set so that the driver has enough time to recognize the request for a driver changeover and to start monitoring the surroundings. As an example, the threshold distance is set to about 500 m. The threshold distance may be set longer as the set vehicle speed of the host vehicle Am when traveling through the transition section CS increases. The threshold distance may be changeable by a user setting such as a driver.

[0054] The control switching unit 77 switches between, as driving controls with different automation levels, eyes-on autonomous driving control, in which the driver of the host vehicle Am is obligated to monitor the surroundings, and eyes-off autonomous driving control, in which the driver is not obligated to monitor the surroundings.Furthermore, the control switching unit 77 switches between, as driving controls with different automation levels, hands-on autonomous driving control, in which the driver of the host vehicle Am is obligated to hold the steering wheel, and hands-off autonomous driving control, in which the driver is not obligated to hold the steering wheel.Hands-on autonomous driving control and hands-off autonomous driving control are driving controls included in eyes-on autonomous driving control.

[0055] The control switching unit 77 changes the automation level of the driving control by the automatic driving function according to the road type. When a driving route from the expressway KD to the general road ID is set, the control switching unit 77 allows the driving control to continue at the same automation level as on the expressway KD even after the vehicle Am has passed through the exit gate GtE, up to the time when the vehicle Am reaches the first stopping point PsE.

[0056] The control switching unit 77 changes whether or not to maintain the automation level after passing through the exit gate GtE between when the host vehicle Am was traveling on the expressway KD with eyes-on autonomous driving control and when the host vehicle Am was traveling on the expressway KD with eyes-off autonomous driving control. In addition, the control switching unit 77 changes whether or not to maintain the automation level after passing through the exit gate GtE between when the host vehicle Am was traveling on the expressway KD with hands-on autonomous driving control and when the host vehicle Am was traveling on the expressway KD with hands-off autonomous driving control.

[0057] <Case 1: Automation level control when the transition section is long> In case 1, the section length Lc of the transition section CS exceeds the threshold distance. The host vehicle Am is traveling on the expressway KD using eyes-off autonomous driving control (autonomous driving level 3) or hands-off autonomous driving control. If the host vehicle Am has been traveling on the expressway KD using eyes-off autonomous driving control, the control switching unit 77 schedules the end of eyes-off autonomous driving control upon exiting the expressway KD. Similarly, if the host vehicle Am has been traveling on the expressway KD using hands-off autonomous driving control, the control switching unit 77 schedules the end of hands-off autonomous driving control upon exiting the expressway KD.

[0058] When the control switching unit 77 plans to end the ongoing cruise control in conjunction with exiting the expressway KD, it changes the timing of requesting the driver to take over driving in accordance with the section length Lc of the transition section CS. When the section length Lc of the transition section CS exceeds the threshold distance as in Case 1, the control switching unit 77 sets a change request section in the transition section CS after passing through the exit gate GtE to request the driver to take over driving.

[0059] When switching the automation level from eyes-off autonomous driving control to hands-on autonomous driving control, the control switching unit 77 cooperates with the information linkage unit 61 and the HMI control device 100 to issue an eyes-on request and a hands-on request as a driving changeover request in the changeover request section. When switching the automation level from hands-off autonomous driving control to hands-on autonomous driving control, the control switching unit 77 cooperates with the information linkage unit 61 and the HMI control device 100 to issue a hands-on request as a driving changeover request in the changeover request section. The eyes-on request is a notification requesting the driver to start monitoring the surroundings. The hands-on request is a notification requesting the driver to hold the steering wheel. The eyes-on request and hands-on request may be presented simultaneously. Alternatively, the presentation of the hands-on request may be started after a predetermined time has elapsed since the presentation of the eyes-on request began.

[0060] After the host vehicle Am moves onto the transition section CS, the control switching unit 77 changes at least one of the set inter-vehicle distance and the set vehicle speed in the cruise control while maintaining the automation level on the expressway KD. The control switching unit 77 makes the set inter-vehicle distance in the transition section CS wider than the set inter-vehicle distance used in the cruise control after passing the stop point PsE. In addition, the control switching unit 77 makes the set vehicle speed in the transition section CS lower than the set vehicle speed used in the cruise control after passing the stop point PsE. After changing the set inter-vehicle distance and the set vehicle speed in the transition section CS, the control switching unit 77 requests the driver to take over driving. After requesting the driver to take over driving, the control switching unit 77 switches the control state of the host vehicle Am from eyes-off autonomous driving control or hands-off autonomous driving control to hands-on autonomous driving control in the transition section CS.

[0061] <Case 2: Automation level control when the transition section is short> In Case 2, the host vehicle Am is traveling on the expressway KD using eyes-off automated driving control or hands-off automated driving control, as in Case 1. In Case 2, the section length Lc of the transition section CS is less than (or equal to) the threshold distance. When the section length Lc of the transition section CS is less than (or equal to) the threshold distance, the control switching unit 77 requests the driver to take over driving while the host vehicle Am is traveling on the main roadway before passing through the exit gate GtE. That is, the control switching unit 77 sets a switch request section on the main roadway before passing through the exit gate GtE. The control switching unit 77 makes an eyes-on request (and hands-on request) in the switch request section on the main roadway, and switches the control state of the host vehicle Am from eyes-off automated driving control or hands-off automated driving control to hands-on automated driving control.

[0062] The control switching unit 77 changes the set inter-vehicle distance and set vehicle speed in the hands-on automated driving control in the transition section CS after the host vehicle Am has passed through the exit gate GtE. As in Case 1, the control switching unit 77 makes the set inter-vehicle distance in the transition section CS wider than the set inter-vehicle distance applied after passing the stopping point PsE. In addition, the control switching unit 77 makes the set vehicle speed in the transition section CS lower than the set vehicle speed applied after passing the stopping point PsE.

[0063] <Case 3: Automation level control during driving using hands-on automated driving control> In case 3, the host vehicle Am is driving on the highway KD using hands-on automated driving control. As described above, hands-on automated driving control corresponds to eyes-on automated driving control, in which the driver is required to monitor the surroundings. The control switching unit 77 continues driving the host vehicle Am using hands-on automated driving control even after passing through the exit gate GtE.

[0064] As in Case 2, the control switching unit 77 changes the set inter-vehicle distance and set vehicle speed in the hands-on autonomous driving control in the transition section CS after the host vehicle Am has passed through the exit gate GtE. The control switching unit 77 changes the settings to increase the set inter-vehicle distance and decrease the set vehicle speed in the transition section CS.

[0065] <Case 4: Automation Level Control When Switching to Manual Driving is Necessary> In Case 4, the host vehicle Am is traveling on the expressway KD using eyes-off autonomous driving control (autonomous driving level 3). The control switching unit 77 plans to end eyes-off autonomous driving control and switch the automation level to manual driving (autonomous driving level 0) upon exiting the expressway KD. In this case, the road recognition unit 74 references road information for the sections before and after the toll gate TG and determines whether there is an evacuation area EA in the transition section CS after the exit gate GtE. The evacuation area EA is an area large enough to allow the host vehicle Am to temporarily stop after leaving the lane in the transition section CS. The road recognition unit 74 sets the evacuation area EA, for example, in a shoulder area close to the edge of the road immediately after the exit gate GtE.

[0066] If there is an evacuation area EA after the exit gate GtE, the control switching unit 77 stops the host vehicle Am in the evacuation area EA after passing through the exit gate GtE. With the host vehicle Am temporarily stopped in the evacuation area EA, the control switching unit 77 cooperates with the information linkage unit 61 and the HMI control device 100 to issue a driving change request to the driver requesting the start of all driving operations. The control switching unit 77 terminates the eyes-off automatic driving control based on the start of driving operations by the driver. The host vehicle Am travels through the transition section CS under the driving operations of the driver and heads toward the stopping point PsE.

[0067] If there is no evacuation area EA in the transition section CS, the control switching unit 77 continues driving under eyes-off automatic driving control until the stopping point PsE. The control switching unit 77 switches driving while the host vehicle Am is stopped at the stopping point PsE and switches to manual driving by the driver. As another example, the control switching unit 77 may switch to manual driving by the driver while continuing driving in the transition section CS.

[0068] [Automation level control process when exiting an expressway] Next, details of the automation level control process for changing or maintaining the automation level of driving control when exiting an expressway KD onto an ordinary road ID will be described based on Figures 5 and 6 and with reference to Figures 1 to 4. The automation level control process is started by the autonomous driving ECU 50 when autonomous driving level 2 or higher driving control is executed on the expressway KD.

[0069] 5 , the road recognition unit 74 acquires route information generated by the navigation ECU 38. In S12, the road recognition unit 74 acquires road information for roads that will be the driving route of the host vehicle Am based on the route information. Based on the acquired road information, the road recognition unit 74 acquires road type information for the roads that will be the driving route, indicating whether they are expressways (KD) or general roads (ID).

[0070] In S13, the road recognition unit 74 determines whether or not an exit from the expressway KD to an ordinary road ID is planned. If the vehicle is scheduled to continue traveling on the expressway KD (S13: NO), the road recognition unit 74 repeats the processes of S11 and S12. On the other hand, if the vehicle is scheduled to exit the expressway KD (S13: YES), the control switching unit 77 determines in S14 whether or not a switch to manual driving is planned.

[0071] If a switch to manual driving is planned (S14: YES), the road recognition unit 74 determines whether the evacuation area EA is located in the transition section CS in S31 shown in FIG. 6. If the evacuation area EA is located in the transition section CS (S31: YES), stop control is implemented in S32 to stop the host vehicle Am in the evacuation area EA. On the other hand, if the evacuation area EA is not located in the transition section CS (S31: NO), stop control is implemented in S33 to stop the host vehicle Am at the stopping point PsE. In S34, the control switching unit 77 requests the driver to take over driving while the host vehicle Am is stopped in the evacuation area EA or the stopping point PsE, and switches the control state of the host vehicle Am to manual driving.

[0072] On the other hand, if switching to a mode other than manual driving (such as hands-on automated driving) is planned (S14: NO), the control switching unit 77 determines the automation level of the driving control currently being executed in S15 shown in Fig. 5. The control switching unit 77 determines whether the host vehicle Am is driving under hands-on automated driving control.

[0073] When the host vehicle Am is traveling on the expressway KD under eyes-off autonomous driving control or hands-off autonomous driving control (S15: NO), the road recognition unit 74 recognizes the section length Lc of the transition section CS in S16. The road recognition unit 74 determines whether the section length Lc is longer than a threshold distance. When the section length Lc of the transition section CS is equal to or shorter than the threshold distance (S16: NO), the control switching unit 77 sets a changeover request section on the main roadway just before the exit gate GtE, requesting a changeover of driving. In S17, the control switching unit 77 determines whether the host vehicle Am has reached the changeover request section. When the host vehicle Am has not reached the changeover request section (S17: NO), the control switching unit 77 waits for the host vehicle Am to arrive at the changeover request section. When the host vehicle Am reaches the changeover request section (S17: YES), the control switching unit 77 executes the eyes-on request or the hands-on request, whichever is necessary for the current driving changeover. As a result, if the section length Lc of the transition section CS is equal to or less than the threshold distance, a driving changeover is requested before passing through the exit gate GtE.

[0074] When the vehicle is traveling on the expressway KD under hands-on automated driving control (S15: YES), or when switching to hands-on automated driving control has been performed, the control switching unit 77 determines in S19 whether the vehicle Am has passed through the exit gate GtE. If the vehicle Am has not yet passed through the exit gate GtE (S19: NO), the control switching unit 77 waits for the vehicle Am to pass through the exit gate GtE. Then, when the vehicle Am passes through the exit gate GtE (S19: YES), the control switching unit 77 adjusts at least one of the set inter-vehicle distance and the set vehicle speed in S20. As described above, when hands-on automated driving control is being performed on the expressway KD, the hands-on automated driving control continues even after the vehicle passes through the exit gate GtE.

[0075] On the other hand, if the section length Lc of the transition section CS exceeds the threshold distance (S16: YES), the control switching unit 77 sets a changeover request section in the transition section CS. In S21, the control switching unit 77 determines whether the host vehicle Am has passed through the exit gate GtE. If the host vehicle Am has not yet passed through the exit gate GtE (S21: NO), the control switching unit 77 waits for the host vehicle Am to pass through the exit gate GtE. Then, when the host vehicle Am has passed through the exit gate GtE (S21: YES), the control switching unit 77 adjusts at least one of the set inter-vehicle distance and the set vehicle speed in S22.

[0076] In S23, the control switching unit 77 determines whether the host vehicle Am has reached the changeover request section set in the transition section CS. If the host vehicle Am has not reached the changeover request section (S23: NO), the control switching unit 77 waits for the host vehicle Am to reach the changeover request section. Then, when the host vehicle Am reaches the changeover request section (S23: YES), the control switching unit 77 implements, in S24, the eyes-on request or the hands-on request that is required for this driving changeover. As described above, if the section length Lc of the transition section CS exceeds the threshold distance, driving control at the same automation level as on the expressway KD continues even after passing through the exit gate GtE, and a driving changeover request is made to the driver before passing through the stop point PsE.

[0077] (Summary of First Embodiment) In the first embodiment described so far, even after passing through the exit gate GtE of the expressway KD, cruise control can be continued at the same automation level as on the expressway KD up to the stopping point PsE where the host vehicle Am temporarily stops. Then, in the section beyond the stopping point PsE on the general road ID, cruise control can be implemented at the automation level corresponding to the general road ID. As a result, cruise control by the automated driving function can be appropriately continued even after passing through the exit gate GtE.

[0078] In addition, in the first embodiment, in the transition section CS from the exit gate GtE to the stopping point PsE, at least one of the set inter-vehicle distance and set vehicle speed in the cruise control is changed while maintaining the automation level on the expressway KD. As a result, even after the host vehicle Am has passed the exit gate GtE while maintaining the automation level, the host vehicle Am can continue to cruise with cruise control appropriate for the road environment of the transition section CS.

[0079] In the first embodiment, the set inter-vehicle distance in the transition section CS is changed to be wider than the set inter-vehicle distance used in cruise control after passing through the stop point PsE. Alternatively, the set vehicle speed in the transition section CS is changed to be lower than the set vehicle speed used in cruise control after passing through the stop point PsE. As a result, even if the host vehicle Am passes through the exit gate GtE while maintaining the automation level, the traveling mode of the host vehicle Am can be pre-adjusted in the transition section CS to a mode suitable for traveling on the general road ID after passing through the stop point PsE.

[0080] Furthermore, in the first embodiment, when cruise control is scheduled to end upon exiting the expressway KD, the timing at which the driver of the host vehicle Am is requested to take over driving is changed depending on the section length Lc of the transition section CS. As a result, even in a configuration in which the automation level is allowed to be maintained even after passing through the exit gate GtE, the driver can be requested to take over driving at an appropriate timing.

[0081] Additionally, in the first embodiment, if the section length Lc is less than the threshold distance, a driver changeover is requested before passing through the exit gate GtE. On the other hand, if the section length Lc exceeds the threshold distance, a driver changeover is requested in the transition section CS after passing through the exit gate GtE. Based on the above, a situation in which a driver changeover request is made to the driver in a state in which there is not enough time to ensure a driver changeover in the transition section CS with a short section length Lc can be avoided. Furthermore, if the section length Lc of the transition section CS is ensured, a driver changeover request to the driver can be made when the vehicle Am is traveling stably.

[0082] In the first embodiment, when cruise control is scheduled to end upon exiting the expressway KD, the road recognition unit 74 determines whether an evacuation area EA where the host vehicle Am can retreat is located within the transition section CS. If the evacuation area EA is located after the exit gate GtE, the host vehicle Am stops in the evacuation area EA. Based on the above, when switching to manual driving is performed upon the end of cruise control, the driver can regain their driving sense by driving manually through the transition section CS. As a result, the driver can smoothly resume driving on the general road ID.

[0083] Furthermore, in the first embodiment, the driver is requested to take over driving when the host vehicle Am is stopped in the evacuation area EA. As a result, the driver can start monitoring the surroundings and performing driving operations while the host vehicle Am is stopped in the evacuation area EA in a stable state. As a result, the driver can calmly acquire control and start driving through the transition section CS.

[0084] In addition, in the first embodiment, whether or not to maintain the automation level after passing through the exit gate GtE is changed depending on whether or not the vehicle is traveling on the expressway KD with eyes-on automated driving control and whether or not the vehicle is traveling on the expressway KD with eyes-off automated driving control. As a result, it is possible to appropriately determine whether or not to continue the same driving control as on the expressway KD depending on the automation level of driving control permitted on the general road ID.

[0085] Furthermore, in the first embodiment, if the host vehicle Am is traveling on the expressway KD under eyes-on autonomous driving control, the eyes-on autonomous driving control continues even after passing through the exit gate GtE. In contrast, if the host vehicle Am is traveling on the expressway KD under eyes-off autonomous driving control, the eyes-off autonomous driving control ends in the transition section CS. As described above, when the implementation of eyes-off autonomous driving control is prohibited on the general road ID but the implementation of eyes-on autonomous driving control is permitted on the general road ID, the automation level of driving control after passing through the exit gate GtE can be appropriately controlled.

[0086] Furthermore, in the first embodiment, if the host vehicle Am is traveling on the expressway KD under hands-on automated driving control, the hands-on automated driving control continues even after passing through the exit gate GtE. In contrast, if the host vehicle Am is traveling on the expressway KD under hands-off automated driving control, a switch to hands-on automated driving control is performed in the transition section CS. Based on the above, when the implementation of hands-off automated driving control is prohibited on the general road ID but the implementation of hands-on automated driving control is permitted on the general road ID, the automation level of driving control after passing through the exit gate GtE can be appropriately controlled.

[0087] In the first embodiment, the automatic driving ECU 50 corresponds to the "automatic driving control device", the road grasping unit 74 corresponds to the "road information acquisition unit", and the control switching unit 77 corresponds to the "control change unit".

[0088] Second Embodiment A second embodiment of the present disclosure is a modified example of the first embodiment. In the second embodiment, as eyes-on autonomous driving control for autonomous driving level 2, only hands-on autonomous driving is implemented out of hands-off autonomous driving control and hands-on autonomous driving control. The autonomous driving ECU 50 does not implement hands-off autonomous driving control in accordance with regulations, for example, laws and regulations. The control switching unit 77 switches between eyes-off autonomous driving control, in which the driver is not required to monitor the surroundings or hold the vehicle, and hands-on autonomous driving control, in which the driver is required to monitor the surroundings and hold the vehicle, as driving control with different automation levels.

[0089] In the automation level control process of the second embodiment shown in Fig. 7, processes of S215 to S217 are performed instead of the processes of S15 and S16 in the automation level control process of the first embodiment (see Fig. 5). The processes performed in S11 to S14 and S17 to S24 in the second embodiment are substantially the same as the processes performed in each step in the first embodiment.

[0090] If a switch to control other than manual driving is scheduled in conjunction with exiting the expressway KD (S14: NO), the control switching unit 77 determines in S215 whether driving control of autonomous driving level 3 or higher (eyes-off autonomous driving control) is being executed. If driving control of autonomous driving level 2 or lower (hands-on autonomous driving control) is being executed (S215: NO), the control switching unit 77 adjusts at least one of the set inter-vehicle distance and the set vehicle speed (S19) and continues hands-on autonomous driving control even after passing through the exit gate GtE.

[0091] On the other hand, if driving control of autonomous driving level 3 or higher is being executed (S215: YES), the road recognition unit 74 determines in S216 whether the section length Lc of the transition section CS is longer than the threshold distance. If the section length Lc of the transition section CS is equal to or shorter than the threshold distance (S216: NO), the control switching unit 77 issues an eyes-on request and a hands-on request to the driver on the main roadway just before the exit gate GtE (S18).

[0092] On the other hand, if the section length Lc of the transition section CS exceeds the threshold distance (S216: YES), the control switching unit 77 determines in S217 whether the pre-gate area FS is a driving environment with a high driving load. The pre-gate area FS is an area located in front of the gate. If the exit gate GtE is on the main roadway of the expressway KD, the main road section in front of the exit gate GtE is the pre-gate area FS (see the center of Figure 3). Also, if the exit gate GtE is located in the middle of a rampway, the rampway section branching off from the main roadway is the pre-gate area FS (see the upper left of Figure 3). The control switching unit 77 determines that the driving environment is high driving load when there are multiple branches near the exit gate GtE or when there are many vehicles in the pre-gate area FS. A driving environment with a high driving load is also a driving environment with a high level of difficulty for autonomous driving.

[0093] If the gate front area FS is not a driving environment with a high driving load (S217: NO), the control switching unit 77 issues an eyes-on request and a hands-on request to the driver on the main roadway just before the exit gate GtE (S18), as in the case where the transition section CS is short. On the other hand, if the gate front area FS is a driving environment with a high driving load (S217: YES), the control switching unit 77 issues an eyes-on request and a hands-on request to the driver in the transition section CS after passing through the exit gate GtE (S24).

[0094] (Summary of Second Embodiment) The second embodiment described so far also achieves the same effects as the first embodiment, and allows appropriate continuation of travel control by the automatic driving function even after passing through the exit gate GtE.

[0095] Additionally, in the second embodiment, when the end of cruise control is scheduled upon exiting the expressway KD, a determination is made as to whether the pre-gate area FS is a driving environment with a high driving load. If the section length Lc of the transition section CS exceeds the threshold distance and the pre-gate area FS is a driving environment with a high driving load, a request for a driver handover is made to the driver after passing through the exit gate GtE. Based on the above, cruise control at the same automation level as the expressway KD can be appropriately extended in situations where a driver handover in the pre-gate area FS is highly difficult, while a driver handover in the transition section CS may be less difficult. As a result, it is possible to smoothly transfer at least a portion of the driving control restrictions to the driver.

[0096] (Third Embodiment) The third embodiment of the present disclosure is another modified example of the first embodiment. In the third embodiment, the automation level of cruise control permitted for the host vehicle Am on the general road ID after the stop point PsE where a road branch occurs is determined in advance before passing through the exit gate GtE. The automation level permitted from the exit gate GtE (gate point PgE) to the stop point PsE changes depending on the automation level permitted on the general road ID after the road branch. Below, details of multiple patterns of control for changing or maintaining the allowed automation level on the transition section CS from the expressway KD to the general road ID will be described based on Figures 8 and 9, with reference to Figures 1 and 2.

[0097] <Pattern 1: Allowing a higher automation level than on general roads> When a driving route from the expressway KD to a general road ID is set by the navigation ECU 38, the road identification unit 74 acquires road information around the stop point PsE in addition to road information around the toll gate TG. The road identification unit 74 acquires information indicating the automation level allowed for the host vehicle Am on the general road ID that is part of the planned driving route beyond the stop point PsE. The automation level of driving control allowed on the general road ID after the stop point PsE is set based on, for example, laws and regulations. The road identification unit 74 may also use information such as the presence or absence of traffic congestion and weather on the general road ID after the stop point PsE to determine the automation level of driving control allowed for the host vehicle Am.

[0098] The control switching unit 77 determines the automation level of the driving control to be executed on the general road ID after the stop point PsE based on the information grasped by the road grasping unit 74. The control switching unit 77 changes the automation level allowed in the transition section CS from the exit gate GtE (gate point PgE) to the stop point PsE, depending on the automation level allowed on the general road ID beyond the stop point PsE.

[0099] In the automation level control of pattern 1 shown in Figure 8, the automation level allowed in the transition section CS is set higher than the automation level allowed on the general road ID beyond the stopping point PsE. As an example, the control switching unit 77 allows the use of driving control with an automation level one level higher than the automation level allowed on the general road ID in the transition section CS.

[0100] Specifically, if hands-off automated driving is permitted on the general road ID after the stop point PsE, the control switching unit 77 permits eyes-off automated driving in the transition section CS. In such a case, if the host vehicle Am has been traveling on the expressway KD under eyes-off automated driving control or hands-off automated driving control, the control switching unit 77 allows the host vehicle Am to continue driving under the same automated level as the expressway KD even after passing through the exit gate GtE. The control switching unit 77 can permit traveling under eyes-off automated driving control or hands-off automated driving control until the host vehicle reaches the stop point PsE. The control switching unit 77 switches the control state of the host vehicle Am from eyes-off automated driving control or hands-off automated driving control to hands-off automated driving control when the host vehicle Am temporarily stops at the stop point PsE. Furthermore, when the host vehicle Am is traveling on the highway KD using eyes-off autonomous driving control, the control switching unit 77 may switch from eyes-off autonomous driving control to hands-off autonomous driving control in the transition section CS before reaching the stopping point PsE.

[0101] Furthermore, if hands-on automated driving is permitted on the general roads ID after the stop point PsE, the control switching unit 77 permits hands-off automated driving in the transition section CS. In such a case, if the host vehicle Am is traveling on the expressway KD under eyes-off automated driving control or hands-off automated driving control, the control switching unit 77 sets a switch request section on the main roadway just before the gate point PgE. The control switching unit 77 issues an eyes-on request and a hands-on request in the switch request section, and switches the control state of the host vehicle Am to hands-on automated driving control. In addition, if the host vehicle Am is traveling on the expressway KD under hands-on automated driving control, the control switching unit 77 allows hands-on automated driving control to continue even after passing the exit gate GtE until the host vehicle reaches the stop point PsE.

[0102] Here, if the host vehicle Am is traveling on the expressway KD under eyes-off autonomous driving control, the control switching unit 77 may temporarily allow the vehicle to continue traveling under eyes-off autonomous driving control even after passing through the exit gate GtE. The control switching unit 77 gradually lowers the automation level in the transition section CS in the order of eyes-off autonomous driving control, hands-off autonomous driving control, and hands-on autonomous driving control, thereby reducing the burden on the driver associated with the transition of the control state.

[0103] Furthermore, if only manual driving is permitted on the general road ID after the stopping point PsE, the control switching unit 77 permits the use of automation level 1 driving assistance control in the transition section CS. Automation level 1 driving assistance control is driving control in which the system controls either the longitudinal or lateral direction of the host vehicle Am under specific conditions. For example, automation level 1 driving assistance control includes driving control to follow a preceding vehicle using the ACC (Adaptive Cruise Control) function and lane keeping control using the LKA (Lane Keep Assist) function. Even in such a case, if the host vehicle Am is traveling on the expressway KD using eyes-off autonomous driving control or eyes-on autonomous driving control, the control switching unit 77 sets a changeover request section on the main roadway just before the exit gate GtE. The control switching unit 77 requests the driver to change driving mode in the changeover request section and switches the control state of the host vehicle Am to ACC control or manual driving.

[0104] <Pattern 2: Only the same automation level as that of general roads is allowed> In the automation level control of pattern 2 shown in Figure 9, the automation level allowed in the transition section CS is set to be the same as the automation level allowed on the general road ID beyond the stopping point PsE. As an example, the control switching unit 77 allows the use of driving control in the transition section CS that is the same as the automation level allowed on the general road ID.

[0105] Specifically, if hands-off automated driving is permitted on the general road ID after the stop point PsE, the control switching unit 77 also permits hands-off automated driving in the transition section CS. In such a case, if the host vehicle Am is traveling on the expressway KD under eyes-off automated driving control, the control switching unit 77 switches to hands-off automated driving control just before the exit gate GtE. Also, if the host vehicle Am is traveling on the expressway KD under hands-off automated driving control, the control switching unit 77 can permit hands-off automated driving control even after passing the exit gate GtE until the host vehicle reaches the stop point PsE. Note that the control switching unit 77 may temporarily permit eyes-off automated driving control even after passing the exit gate GtE. In this case, the control switching unit 77 switches the control state from eyes-off automated driving control or hands-off automated driving control to hands-on automated driving control in the transition section CS.

[0106] Furthermore, if hands-on automated driving is permitted on the general roads ID after the stopping point PsE, the control switching unit 77 also permits hands-on automated driving in the transition section CS. In such a case, if the host vehicle Am is traveling on the expressway KD using eyes-off automated driving control or hands-off automated driving control, the control switching unit 77 switches to hands-on automated driving control just before the exit gate GtE. Even in such a case, the control switching unit 77 may temporarily permit driving using eyes-off automated driving control or hands-off automated driving control even after passing through the exit gate GtE.

[0107] Furthermore, if only manual driving is permitted on the general road ID after the stopping point PsE, the control switching unit 77 does not permit driving under automatic driving control in the transition section CS. In such a case, if the host vehicle Am is driving on the expressway KD under eyes-off automatic driving control or eyes-on automatic driving control, the control switching unit 77 requests the driver to take over driving just before the exit gate GtE and hands over control to the driver.

[0108] [Details of the automation level control process] Next, details of the automation level control process of the third embodiment will be described based on Fig. 10 with reference to Figs. 1, 2, 8, and 9. Note that steps S11 to S13 of the automation level control process are substantially the same as those in the first embodiment.

[0109] If a planned exit from the expressway KD is determined in S13 of the automation level control process shown in Figure 10 (S13: YES), the road identification unit 74 determines the automation level allowable for the general road ID beyond the stop point PsE in S314. In S315, the control switching unit 77 sets the automation level allowable in the transition section CS according to the automation level allowable for the general road beyond the stop point PsE. In S315, an automation level one level higher than the general road ID may be set, as in the above-mentioned pattern 1 (see Figure 8), or the same automation level as the general road ID may be set, as in the above-mentioned pattern 2 (see Figure 9).

[0110] In S316, the control switching unit 77 compares the automation level permitted in the transition section CS with the automation level of the driving control currently being executed, and determines whether or not it is necessary to lower the automation level. If it is necessary to lower the automation level (S316: YES), the control switching unit 77 sets a changeover request section on the main roadway just before the exit gate GtE. In S17, the control switching unit 77 determines whether or not the host vehicle Am has reached the changeover request section. When the host vehicle Am has reached the changeover request section (S17: YES), in S18, the control switching unit 77 implements the request required for this driving changeover, out of the eyes-on request and the hands-on request.

[0111] If it is not necessary to lower the automation level (S316: NO) or if a request for a driver changeover has been made, the control switching unit 77 determines in S21 whether the host vehicle Am has passed through the exit gate GtE. If the control switching unit 77 determines that the host vehicle Am has passed through the exit gate GtE (S21: YES), it adjusts at least one of the set inter-vehicle distance and the set vehicle speed in S22.

[0112] In S322, the control switching unit 77 compares the automation level permitted for the general road ID with the automation level of the driving control currently being executed in the transition section CS, and determines whether it is necessary to lower the automation level. If it is not necessary to lower the automation level (S322: NO), the automation level control process is terminated. On the other hand, if it is necessary to lower the automation level (S322: YES), the control switching unit 77 sets a changeover request section in the transition section CS. In this case, the changeover request section may be set immediately before the stop point PsE.

[0113] In S23, the control switching unit 77 determines whether the host vehicle Am has reached the changeover request section set in the transition section CS. When the host vehicle Am has reached the changeover request section (S23: YES), in S24, the control switching unit 77 implements the eyes-on request or the hands-on request that is required for this driving changeover. If it is necessary to lower the automation level by multiple steps, the processes of S23 and S24 are repeated. As a result, the automation level is gradually lowered in the transition section CS.

[0114] (Summary of the third embodiment) The third embodiment described so far also achieves the same effects as the first and second embodiments, and allows appropriate continuation of driving control using the automatic driving function even after passing through the exit gate GtE.

[0115] Additionally, in the third embodiment, information indicating the automation level permitted on the general road ID beyond the stop point PsE is further acquired. The automation level permitted in the transition section CS from the exit gate GtE to the stop point PsE is then changed according to the automation level permitted on the general road ID beyond the stop point PsE. This makes it possible to avoid a sudden change in automation level near the stop point PsE. As a result, the burden on the driver can be reduced when heading from the expressway KD to the general road ID.

[0116] In the third embodiment, the automation level permitted in the transition section CS is set higher than the automation level permitted on the general road ID beyond the stop point PsE. This control makes it possible to gradually lower the automation level when heading from the expressway KD to the general road ID. As a result, the burden on the driver can be more reliably reduced. The automation level in the transition section CS may be set two or more levels higher than the automation level on the general road ID.

[0117] Furthermore, in the third embodiment, the automation level permitted in the transition section CS is set to the same as the automation level permitted on the general road ID beyond the stop point PsE. This control prevents the automation level of the automated driving control from changing near the stop point PsE, where the driving load increases. As a result, the driver's load can be more reliably reduced when heading from the expressway KD to the general road ID.

[0118] Fourth Embodiment The fourth embodiment of the present disclosure shown in FIG. 11 is a modified example of the third embodiment. In the fourth embodiment, the distance of a transition section CS from the gate point PgE to the stop point PsE where a road branch occurs is determined in advance before passing through the exit gate GtE. The automation level permitted in the transition section CS changes depending on the section length Lc, which is the distance of the transition section CS. The control switching unit 77 sets a higher automation level permitted for the host vehicle Am in the transition section CS as the section length Lc of the transition section CS increases.

[0119] Specifically, similar to the first embodiment, the road recognition unit 74 recognizes the section length Lc of the transition section CS and compares the recognized section length Lc with a threshold distance (e.g., approximately 500 m). The road recognition unit 74 determines whether the section length Lc exceeds the threshold distance. If the section length Lc exceeds the threshold distance, the control switching unit 77 allows a high level of automation in the transition section CS. As an example, the control switching unit 77 allows driving through the transition section CS under hands-off automated driving control.

[0120] In a case where the section length Lc exceeds the threshold distance, if the host vehicle Am is traveling on the expressway KD under eyes-off autonomous driving control, the control switching unit 77 issues an eyes-on request in the changeover request section set just before the exit gate GtE. As a result, the host vehicle Am proceeds to the transition section CS under eyes-on autonomous driving control (hands-off autonomous driving control). On the other hand, if the host vehicle Am is traveling on the expressway KD under hands-off autonomous driving control, the control switching unit 77 allows the continuation of hands-off autonomous driving control even after passing through the exit gate GtE.

[0121] The control switching unit 77 gradually lowers the automation level of the host vehicle Am, which is traveling under hands-off autonomous driving control, in the transition section CS. The control switching unit 77 issues a hands-on request before the host vehicle Am reaches the stop point PsE, and switches the control state from hands-off autonomous driving control to hands-on autonomous driving control. Then, the control switching unit 77 switches from hands-on autonomous driving control to manual driving when the host vehicle Am temporarily stops at the stop point PsE. Note that the control switching unit 77 may continue hands-off autonomous driving control until the host vehicle reaches the stop point PsE. In this case, switching from hands-off autonomous driving control to manual driving is performed when the host vehicle Am temporarily stops at the stop point PsE.

[0122] On the other hand, if the section length Lc is equal to or less than the threshold distance, the control switching unit 77 allows only low-level automation in the transition section CS. For example, the control switching unit 77 allows only the use of driving assistance control of automation level 1, or prohibits the use of driving assistance control and automated driving control.

[0123] When the section length Lc is equal to or less than the threshold distance and the host vehicle Am is traveling on the expressway KD under automated driving control, the control switching unit 77 issues an eyes-on request and a hands-on request before passing through the exit gate GtE. As a result, the host vehicle Am travels through the transition section CS under automated level 1 driving assistance control or manual driving.

[0124] In the automation level control process of the fourth embodiment (see FIG. 10 ), a comparison between the section length Lc and the threshold distance is performed as a process replacing S314. In S315, the automation level to be allowed in the transition section CS is set based on the comparison result in S314. In the subsequent processes, the automation level is lowered based on the allowable automation level set in S315.

[0125] (Summary of the fourth embodiment) The fourth embodiment described so far also achieves the same effects as the first to third embodiments, and allows appropriate continuation of driving control using the automatic driving function even after passing through the exit gate GtE.

[0126] Additionally, in the fourth embodiment, the longer the section length Lc of the transition section CS, the higher the automation level allowed in the transition section CS. As described above, a situation in which the driver is required to keep their eyes on the road and their hands on the road in rapid succession can be avoided in a transition section CS with a short section length Lc. In other words, the driver can respond to a request to lower the automation level in a relatively stable driving environment on the main roadway. As a result, a smooth lowering of the automation level becomes possible when heading from the expressway KD to an ordinary road ID.

[0127] In the fourth embodiment, when the section length Lc exceeds the threshold distance, the automation level is gradually reduced in the transition section CS. This allows the driver to take over driving operations from the system with ample time to maneuver. As a result, the automation level can be smoothly reduced even in situations where the section length Lc of the transition section CS is sufficiently secured.

[0128] (Other Embodiments) Although multiple embodiments of the present disclosure have been described above, the present disclosure should not be construed as being limited to the above-described embodiments, and can be applied to various embodiments and combinations within the scope that does not deviate from the gist of the present disclosure.

[0129] In Modification 1 of the above embodiment, after passing through the exit gate GtE, only one of the set inter-vehicle distance and set vehicle speed used for cruise control is changed. Furthermore, in Modification 2 of the above embodiment, after passing through the exit gate GtE, at least one of the set inter-vehicle distance and set vehicle speed used for cruise control is set to a greater margin than the set inter-vehicle distance and set vehicle speed used while traveling on the expressway KD. Specifically, the control switching unit 77 sets the set inter-vehicle distance after passing through the exit gate GtE to be wider than the set inter-vehicle distance used for cruise control on the expressway KD. Furthermore, the control switching unit 77 sets the set vehicle speed after passing through the exit gate GtE to be lower than the set vehicle speed used for cruise control on the expressway KD. Furthermore, the control switching unit 77 may gradually change at least one of the set inter-vehicle distance and set vehicle speed after passing through the exit gate GtE.

[0130] The set inter-vehicle distance is a value indicating the target inter-vehicle time between the host vehicle Am and the preceding vehicle. When the set inter-vehicle distance is the same, the higher the traveling speed of the host vehicle Am, the wider the inter-vehicle distance VD, and the lower the traveling speed of the host vehicle Am, the narrower the inter-vehicle distance VD. In the following cruise control, the autonomous driving ECU 50 manages the traveling speed of the host vehicle Am so that the inter-vehicle distance based on the target inter-vehicle time is maintained. The control switching unit 77 switches the set inter-vehicle distance between three levels, such as "long (far), medium, short (close)," or five levels, such as "long, somewhat long, medium, somewhat short, short."

[0131] In a third modification of the above embodiment, the timing of the driver change request is not changed based on the section length Lc of the transition section CS. In the third modification, the driver change request is made after passing through the exit gate GtE, regardless of the section length Lc. In this third modification, if the pre-gate area FS is a driving environment with a high driving load, the driver change request is made after passing through the exit gate GtE, regardless of the section length Lc.

[0132] In a fourth modification of the above embodiment, the vehicle switches from eyes-off autonomous driving or hands-off autonomous driving to manual driving while continuing to drive in the transition section CS. As in the fourth modification, when switching to manual driving, the vehicle does not need to temporarily stop at the evacuation area EA or the like.

[0133] The autonomous driving ECU 50 of the fifth modification of the above embodiment is capable of executing autonomous driving level 4 or autonomous driving level 5 driving control on the expressway KD. In this fifth modification, a switch from autonomous driving level 4 or level 5 to hands-on autonomous driving control or manual driving (a driver handover request) is made in the transition section CS after passing through the exit gate GtE. Furthermore, if eyes-off autonomous driving control or hands-off autonomous driving control is possible (legally or technically) on the general road ID, a switch from level 4 or level 5 autonomous driving control to eyes-off autonomous driving control or hands-off driving may be made in the transition section CS.

[0134] In a sixth modification of the above embodiment, the start of driving control at the same automated level as the expressway KD on which the vehicle is to travel is permitted not only in the transition section CS from the expressway KD to the general road ID, but also in the transition section CS from the general road ID to the expressway KD. In this sixth modification, the vehicle Am passes through the entrance gate GtI with eyes-off automated driving control or hands-off automated driving control activated.

[0135] In a seventh modification of the above embodiment, the functions of the automatic driving ECU 50 and the HMI control device 100 are provided by a single integrated ECU. In this seventh modification, the integrated ECU corresponds to the "automatic driving control device." Furthermore, the automatic driving ECU 50 and the HMI control device 100 may cooperate to realize the functions of the automatic driving control device according to the present disclosure. In this embodiment, a system including the automatic driving ECU 50 and the HMI control device 100 corresponds to the "automatic driving control device."

[0136] In the above embodiment, each function provided by the autonomous driving ECU 50 can be provided by software and hardware that executes the software, software alone, hardware alone, or a combination of these. Furthermore, when such functions are provided by electronic circuits as hardware, each function can also be provided by digital circuits including multiple logic circuits or analog circuits. Furthermore, the software for realizing such functions may include, at least in part, code automatically generated by a neural network or language model trained using a large amount of learning data.

[0137] Each processing unit in the above embodiments is hardware for arithmetic processing coupled to a RAM. The processing unit includes at least one arithmetic core, such as a central processing unit (CPU) and a graphics processing unit (GPU). The processing unit may further include a field-programmable gate array (FPGA), a neural network processing unit (NPU), and an IP core with other dedicated functions. Furthermore, the processing unit is not limited to being individually mounted on a printed circuit board. The processing unit may be mounted on an application-specific integrated circuit (ASIC), a system on chip (SoC), a chiplet integration, an FPGA, or the like.

[0138] In the above embodiments, the form of the storage medium (non-transitory tangible storage medium) that stores various programs and the like may be changed as appropriate. Furthermore, the storage medium is not limited to a configuration provided on a circuit board, but may be provided in the form of a memory card or the like, inserted into a slot, and electrically connected to a control circuit such as an autonomous driving ECU. Furthermore, the storage medium may be an optical disk, hard disk drive, solid state drive, or the like that serves as a source from which programs are copied or distributed to the autonomous driving ECU or the like.

[0139] Vehicles equipped with the above-described autonomous driving ECUs and the like are not limited to general private passenger cars (Personally Owned Vehicles, POVs). Vehicles equipped with these may also be rental cars, manned taxis, ride-sharing vehicles, freight vehicles, buses, etc. Furthermore, vehicles equipped with autonomous driving ECUs and the like may be right-hand drive vehicles or left-hand drive vehicles. Furthermore, the traffic environment in which the vehicle travels may be a traffic environment based on left-hand traffic or a traffic environment based on right-hand traffic. The autonomous driving control and information presentation control according to the present disclosure may be optimized as appropriate according to the road traffic laws of each country and region, as well as the steering wheel position of the vehicle.

[0140] The controller and methods described herein may be implemented by a special-purpose computer comprising a processor programmed to perform one or more functions embodied in a computer program. Alternatively, the apparatus and methods described herein may be implemented by special-purpose hardware logic circuitry. Alternatively, the apparatus and methods described herein may be implemented by one or more special-purpose computers comprising a processor executing a computer program in combination with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium.

[0141] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0142] (Technical Idea 1) An automatic driving control device that controls the driving of a host vehicle (Am) using an automatic driving function, comprising: a road information acquisition unit (74) that acquires information on road type, indicating whether a road on a driving route of the host vehicle is an expressway (KD) or an ordinary road (ID), and a control change unit (77) that changes the automation level of driving control by the automatic driving function in accordance with the road type, wherein, when the driving route from the expressway to the ordinary road is set, the control change unit allows the driving control to continue at the same automation level as on the expressway, even after the host vehicle has passed an exit gate (GtE) of the expressway, until the host vehicle reaches a stopping point (PsE) where it will first stop. (Technical Idea 2) The automatic driving control device according to Technical Idea 1, wherein the control change unit changes at least one of a set inter-vehicle distance and a set vehicle speed in the driving control, while maintaining the automation level on the expressway, in a transition section (CS) from the exit gate to the stopping point. (Technical Idea 3) The automatic driving control device according to Technical Idea 2, wherein the control change unit at least one of: changing the set inter-vehicle distance in the transition section to be wider than the set inter-vehicle distance used in the cruise control after passing the stop point; and changing the set vehicle speed in the transition section to be lower than the set vehicle speed used in the cruise control after passing the stop point. (Technical Idea 4) The automatic driving control device according to any one of Technical Ideas 1 to 3, wherein the control change unit, when planning to end the cruise control in conjunction with exiting the expressway, changes the timing at which the control change unit requests the driver of the host vehicle to take over driving, depending on the section length (Lc) of the transition section (CS) from the exit gate to the stop point. (Technical Idea 5) The automatic driving control device according to Technical Idea 4, wherein the control change unit requests the driving change before passing the exit gate if the section length is less than a threshold distance, and requests the driving change in the transition section after passing the exit gate if the section length exceeds the threshold distance.(Technical Idea 6) The autonomous driving control device according to any one of Technical Ideas 1 to 5, wherein, when the end of the driving control is scheduled in association with exiting the expressway, the control change unit determines whether a pre-gate area (FS) located in front of the exit gate is a driving environment with a high driving load, and when a section length (Lc) of a transition section (CS) from the exit gate to the stopping point exceeds a threshold distance and the pre-gate area is the driving environment with a high driving load, requests the driver of the host vehicle to take over driving after passing through the exit gate. (Technical Idea 7) The autonomous driving control device according to any one of Technical Ideas 1 to 6, when the end of the driving control is scheduled in association with exiting the expressway, the road information acquisition unit determines whether an evacuation area (EA) to which the host vehicle can evacuate is present in the transition section (CS) from the exit gate to the stopping point, and when the evacuation area is present after the exit gate, the control change unit stops the host vehicle in the evacuation area. (Technical Idea 8) The autonomous driving control device according to Technical Idea 7, wherein the control change unit requests the driver of the host vehicle to take over driving while the host vehicle is stopped in the evacuation area. (Technical Idea 9) The autonomous driving control device according to any one of Technical Ideas 1 to 8, wherein the control change unit switches between eyes-on autonomous driving control, in which the driver of the host vehicle is required to monitor their surroundings, and eyes-off autonomous driving control, in which the driver is not required to monitor their surroundings, as the driving control with different automation levels, and changes whether or not to maintain the automation level after passing through the exit gate between a case in which the vehicle has been traveling on the expressway with eyes-on autonomous driving control and a case in which the vehicle has been traveling on the expressway with eyes-off autonomous driving control. (Technical Idea 10) An automatic driving control device according to Technical Idea 9, wherein the control change unit, when driving on the expressway with eyes-on automatic driving control, continues the eyes-on automatic driving control even after passing through the exit gate, and when driving on the expressway with eyes-off automatic driving control, ends the eyes-off automatic driving control in the transition section (CS) from the exit gate to the stopping point.(Technical Idea 11) The autonomous driving control device according to any one of Technical Ideas 1 to 10, wherein the control change unit switches between hands-on autonomous driving control, in which a driver of the host vehicle is required to hold a steering operation unit, and hands-off autonomous driving control, in which the driver is not required to hold a steering operation unit, as the driving control with different automation levels, continues the hands-on autonomous driving control even after passing through the exit gate if the host vehicle has been driving on the expressway under hands-on autonomous driving control, and switches to the hands-on autonomous driving control in a transition section (CS) from the exit gate to the stopping point if the host vehicle has been driving on the expressway under hands-off autonomous driving control. (Technical Idea 12) The autonomous driving control device according to any one of Technical Ideas 1 to 11, wherein the road information acquisition unit further acquires information indicating the automation level permitted on the general roads beyond the stopping point, and the control change unit changes the automation level permitted in the transition section from the exit gate to the stopping point, depending on the automation level permitted on the general roads beyond the stopping point. (Technical Idea 13) The autonomous driving control device according to Technical Idea 12, wherein the control change unit sets the automation level permitted in the transition section to be higher than the automation level permitted on the general road beyond the stopping point. (Technical Idea 14) The autonomous driving control device according to Technical Idea 12, wherein the control change unit sets the automation level permitted in the transition section to be the same as the automation level permitted on the general road beyond the stopping point. (Technical Idea 15) The autonomous driving control device according to any one of Technical Ideas 1 to 14, wherein the control change unit sets the automation level permitted in the transition section to be higher as the section length (Lc) of the transition section (CS) from the exit gate to the stopping point becomes longer. (Technical Idea 16) The autonomous driving control device according to Technical Idea 15, wherein the control change unit gradually lowers the automation level in the transition section when the section length exceeds a threshold distance.(Technical Idea 17) An autonomous driving control program that controls the driving of a host vehicle (Am) using an autonomous driving function, the autonomous driving control program causing at least one processing unit (51) to execute processing including: obtaining road type information indicating whether a road along the driving route of the host vehicle is an expressway (KD) or an ordinary road (ID) (S12); changing the automation level of driving control by the autonomous driving function according to the road type (S18, S24); and, when the driving route from the expressway to the ordinary road is set, allowing the driving control to continue at the same automation level as on the expressway even after the host vehicle has passed an exit gate (GtE) of the expressway until the host vehicle reaches a stopping point (PsE) where it first stops.

Claims

1. An automatic driving control device that controls the driving of a vehicle (Am) using an automatic driving function, comprising: a road information acquisition unit (74) that acquires information on the road type, indicating whether the road that is the driving route of the vehicle is an expressway (KD) or an ordinary road (ID); and a control change unit (77) that changes the automation level of driving control by the automatic driving function according to the road type, wherein when the driving route from the expressway to the ordinary road is set, the control change unit allows the driving control to continue at the same automation level as on the expressway, even after the vehicle has passed through an exit gate (GtE) of the expressway, until the vehicle reaches a stopping point (PsE) where it will first stop.

2. The automatic driving control device of claim 1, wherein the control change unit changes at least one of the set inter-vehicle distance and set vehicle speed in the driving control while maintaining the automation level on the expressway in the transition section (CS) from the exit gate to the stopping point.

3. An automatic driving control device as described in claim 2, wherein the control change unit performs at least one of the following changes: changing the set inter-vehicle distance in the transition section to be wider than the set inter-vehicle distance used in the cruise control after passing the stopping point; and changing the set vehicle speed in the transition section to be lower than the set vehicle speed used in the cruise control after passing the stopping point.

4. The automatic driving control device of claim 1, wherein the control change unit changes the timing of requesting the driver of the vehicle to take over driving depending on the section length (Lc) of the transition section (CS) from the exit gate to the stopping point when the end of the driving control is scheduled in conjunction with exiting the expressway.

5. The automatic driving control device described in claim 4, wherein the control change unit requests the driver change before passing through the exit gate if the section length is less than a threshold distance, and requests the driver change in the transition section after passing through the exit gate if the section length exceeds the threshold distance.

6. The automatic driving control device described in claim 1, wherein the control change unit, when planning to end the driving control upon exiting the expressway, determines whether the driving environment in front of the gate (FS) located in front of the exit gate is a high driving load area, and if the section length (Lc) of the transition section (CS) from the exit gate to the stopping point exceeds a threshold distance and the driving environment in front of the gate is a high driving load area, requests the driver of the vehicle to take over driving after passing through the exit gate.

7. The automatic driving control device described in claim 1, wherein the road information acquisition unit, when the end of the driving control is scheduled upon exiting the expressway, determines whether there is an evacuation area (EA) where the vehicle can escape in the transition section (CS) from the exit gate to the stopping point, and the control change unit, when there is an evacuation area after the exit gate, stops the vehicle in the evacuation area.

8. The automatic driving control device according to claim 7, wherein the control change unit requests the driver of the host vehicle to take over driving while the host vehicle is stopped in the evacuation area.

9. The control change unit switches between eyes-on autonomous driving control, in which the driver of the vehicle is obligated to monitor the surroundings, and eyes-off autonomous driving control, in which the driver is not obligated to monitor the surroundings, as the driving control with different automation levels, and changes whether or not to maintain the automation level after passing through the exit gate between when the vehicle is driving on the expressway with eyes-on autonomous driving control and when the vehicle is driving on the expressway with eyes-off autonomous driving control.

10. The automatic driving control device of claim 9, wherein the control change unit, when driving on the expressway with eyes-on automatic driving control, continues the eyes-on automatic driving control even after passing through the exit gate, and when driving on the expressway with eyes-off automatic driving control, terminates the eyes-off automatic driving control in the transition section (CS) from the exit gate to the stopping point.

11. The automatic driving control device according to claim 1, wherein the control change unit switches between hands-on automatic driving control, in which the driver of the vehicle is obligated to hold the steering operation part, and hands-off automatic driving control, in which the driver is not obligated to hold the steering operation part, as the driving control with different automation levels; when the vehicle is traveling on the expressway under hands-on automatic driving control, the control continues under hands-on automatic driving control even after passing through the exit gate; and when the vehicle is traveling on the expressway under hands-off automatic driving control, the control switches to hands-on automatic driving control in a transition section (CS) from the exit gate to the stopping point.

12. The automatic driving control device described in claim 1, wherein the road information acquisition unit further acquires information indicating the automation level permitted on the general road beyond the stopping point, and the control change unit changes the automation level permitted in the transition section from the exit gate to the stopping point in accordance with the automation level permitted on the general road beyond the stopping point.

13. An automatic driving control device as described in claim 12, wherein the control change unit sets the automation level permitted in the transition section to be higher than the automation level permitted on the general road beyond the stopping point.

14. An automatic driving control device as described in claim 12, wherein the control change unit sets the automation level permitted in the transition section to be the same as the automation level permitted on the general road beyond the stopping point.

15. An automatic driving control device as described in claim 1, wherein the control change unit sets the automation level allowed in the transition section (CS) higher as the section length (Lc) of the transition section (CS) from the exit gate to the stopping point becomes longer.

16. The automatic driving control device according to claim 15, wherein the control change unit gradually lowers the automation level in the transition section when the section length exceeds a threshold distance.

17. An autonomous driving control method for controlling the driving of a host vehicle (Am) using an autonomous driving function, the method including the following steps in processing performed by at least one processing unit (51): obtaining road type information indicating whether a road along the driving route of the host vehicle is an expressway (KD) or an ordinary road (ID) (S12); changing the automation level of driving control by the autonomous driving function according to the road type (S18, S24); and, when the driving route from the expressway to the ordinary road is set, allowing the driving control to continue at the same automation level as on the expressway, even after the host vehicle has passed an exit gate (GtE) of the expressway, until the host vehicle reaches a stopping point (PsE) where it will first stop.

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