JP7697309B2 - Display control device and display control program - Google Patents

Description

This specification discloses a display control device and a display control program that control the display on a head-up display.

For example, Patent Document 1 describes a wrong-way driving warning device that uses image data captured by an on-board camera to determine whether the vehicle is driving the wrong way, and issues a warning to the driver if it is determined that the vehicle is driving the wrong way. In Patent Document 1, the driver is warned by voice from a speaker and a display screen of a display device, etc.

JP 2007-293390 A

As in Patent Document 1, simply warning the driver of wrong-way driving allows the driver to know that the vehicle is driving in the wrong direction, but makes it difficult for the driver to understand information such as the lane the vehicle is currently driving in and where the vehicle should be driving. In this way, wrong-way driving warnings such as those in Patent Document 1 can be insufficiently convenient for the driver.

The present disclosure aims to provide a display control device and a display control program that can increase convenience for drivers by clearly displaying detailed information related to wrong-way driving.

In order to achieve the above object, one disclosed aspect is a display control device used in a vehicle (A) and controlling display by a head-up display (20), comprising: a scene determination unit (73) that determines whether or not a predetermined reverse-driving scene (SnX) anticipated in advance in relation to the vehicle's reverse driving, and a display control unit (76) that causes the head-up display to superimpose reverse-driving prevention content (CTp) that guides the vehicle to drive in the correct driving lane (Lnc) when the predetermined reverse-driving scene occurs, on the road surface in the foreground . The display control unit starts displaying the reverse-driving prevention content based on an on-operation of the vehicle's direction indicator (64), and changes the reverse-driving prevention content displayed based on the on-operation to an emphasized form based on a steering operation that brings the vehicle closer to a center line (CL) that is the boundary between the driving lane and the oncoming lane (Lnw).
Also, one disclosed aspect is a display control device used in a vehicle (A) and controlling display by a head-up display (20), comprising a scene determination unit (73) that determines whether or not a predetermined reverse driving scene (SnX) anticipated in advance in relation to the vehicle's reverse driving is occurring, and a display control unit (76) that causes the head-up display to superimpose reverse driving prevention content (CTp) that guides the vehicle to drive in the correct driving lane (Lnc) when the predetermined reverse driving scene occurs, wherein the scene determination unit further determines whether or not there is an obstacle (Ob) between the driving lane and the oncoming lane (Lnw), and the display control unit is a display control device that interrupts the superimposed display of the reverse driving prevention content by the head-up display when an obstacle is present.

Also, one disclosed aspect is a display control program used in a vehicle (A) for controlling display by a head-up display (20), which causes at least one processing unit (11) to perform processing including determining whether or not a predetermined reverse-running scene (SnX) anticipated in advance in relation to the reverse-running of the vehicle has occurred (S101, S104, S202, S206), and, when the predetermined reverse-running scene has occurred, superimposing reverse-running prevention content (CTp) for guiding the vehicle to run in the correct driving lane (Lnc) on the road surface in the foreground by the head-up display (S102, S105, S203, S210). In the process of superimposing the reverse-running prevention content, the display of the reverse-running prevention content is started based on an ON operation of a direction indicator (64) of the vehicle, and the reverse-running prevention content displayed based on the ON operation is changed to an emphasized form based on a steering operation that brings the vehicle closer to a center line (CL) that is the boundary between the driving lane and the oncoming lane (Lnw) .
One aspect disclosed is a display control program used in a vehicle (A) for controlling display by a head-up display (20), which causes at least one processing unit (11) to execute processing including: determining whether or not a predetermined reverse-driving scene (SnX) anticipated in advance in relation to the reverse driving of a vehicle has occurred (S101, S104, S202, S206); and, if a predetermined reverse-driving scene has occurred, superimposing reverse-driving prevention content (CTp) that guides the vehicle to drive in the correct driving lane (Lnc) on the road surface in the foreground by the head-up display (S102, S105, S203, S210); and further determining whether or not there is an obstacle (Ob) between the driving lane and the oncoming lane (Lnw); and, if an obstacle is present, interrupting the superimposed display of the reverse-driving prevention content by the head-up display.

In these aspects, when the vehicle's driving scene is determined to be a predetermined wrong-way driving scene, wrong-way driving prevention content that guides the vehicle to drive in the correct driving lane is superimposed on the road surface in the foreground by the head-up display. This makes it easier for the driver to grasp information such as the lane the vehicle is currently driving in and where the vehicle should be driving. In this way, detailed information related to wrong-way driving is clearly shown by the superimposed display of wrong-way driving prevention content, thereby making it possible to increase convenience for the driver.

The reference numbers in parentheses above and in the claims are merely examples of the corresponding relationships with the specific configurations in the embodiments described below, and do not limit the technical scope in any way.

1 is a diagram showing an overall view of an in-vehicle network including an HCU according to a first embodiment of the present disclosure. FIG. 1 is a diagram illustrating an example of a head-up display mounted on a vehicle. FIG. 2 is a diagram illustrating an example of a schematic configuration of an HCU. FIG. 13 is a diagram showing an example of a reverse driving prevention content displayed in a first reverse driving scene. FIG. 13 is a diagram showing an example of a reverse-driving prevention content in an emphasis mode displayed in a first reverse-driving scene. FIG. 13 is a diagram showing an example of a reverse driving prevention content displayed in a second reverse driving scene. FIG. 13 is a diagram showing a scene in which the display of the reverse running prevention content is interrupted based on the detection of a section target. 10 is a flowchart showing details of a mode switching process performed by the HCU. 10 is a flowchart showing details of a content display process performed by the HCU. FIG. 13 is a diagram showing an example of reverse driving prevention content displayed in a first reverse driving scene in the second embodiment. FIG. 13 is a diagram showing an example of reverse driving prevention content displayed in a second reverse driving scene in the second embodiment. FIG. 13 is a diagram showing an example of a reverse driving prevention content displayed in a first reverse driving scene in the third embodiment. FIG. 13 is a diagram showing an example of reverse driving prevention content displayed in a second reverse driving scene in the third embodiment. FIG. 13 is a diagram showing an example of a reverse driving prevention content displayed in a first reverse driving scene in the fourth embodiment. FIG. 13 is a diagram showing an example of a reverse driving prevention content displayed in a first reverse driving scene in the fifth embodiment. FIG. 23 is a diagram showing a state in which the display of the reverse driving prevention content is suspended in an overtaking scene in the sixth embodiment. 23 is a flowchart showing details of a content display process according to the sixth embodiment; 13A and 13B are diagrams showing an example of a display image of route guidance content and no entry painting displayed in a route guidance scene in the seventh embodiment. 19 is a diagram showing an example of route guidance content and no entry painting displayed in the route guidance scene shown in FIG. 18. 13 is a diagram showing an example of a display image of route guidance content and no entry painting displayed in a route guidance scene at a multi-junction. FIG.

Below, multiple embodiments of the present disclosure will be described with reference to the drawings. Note that in each embodiment, corresponding components are given the same reference numerals, and duplicated descriptions may be omitted. When only a portion of a configuration is described in each embodiment, the configuration of another embodiment previously described may be applied to the other portions of the configuration. In addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of multiple embodiments may be partially combined even if not explicitly stated, as long as there is no particular problem with the combination. Furthermore, combinations of configurations described in multiple embodiments and modified examples that are not explicitly stated are also considered to be disclosed by the following description.

First Embodiment
The functions of the display control device according to the first embodiment of the present disclosure are realized by an HCU (Human Machine Interface Control Unit) 100 shown in Fig. 1 to Fig. 3. The HCU 100 configures an HMI (Human Machine Interface) system 10 used in a vehicle A together with an in-vehicle display device such as a head-up display (hereinafter, HUD) 20. The HMI system 10 further includes an operation device 26 and a driver status monitor (hereinafter, DSM) 27. The HMI system 10 has an input interface function that accepts user operations by an occupant (e.g., the driver) of the vehicle A, and an output interface function that presents information to the driver.

The HMI system 10 is communicatively connected to a communication bus 99 of an in-vehicle network 1 mounted on a vehicle A. The HMI system 10 is one of a plurality of nodes provided in the in-vehicle network 1. A surroundings monitoring sensor 30, a locator 40, a driving assistance ECU (Electronic Control Unit) 50, a navigation device 52, a steering ECU 61, a body ECU 63, etc. are connected as nodes to the communication bus 99 of the in-vehicle network 1. These nodes connected to the communication bus 99 can communicate with each other. Certain nodes of these devices and ECUs may be directly electrically connected to each other and can communicate without going through the communication bus 99.

In the following description, the front-rear (see forward Ze and rear Go in FIG. 2) and left-right (see side Yo in FIG. 2) directions are defined with respect to vehicle A stationary on a horizontal plane. Specifically, the front-rear direction is defined along the longitudinal direction (direction of travel) of vehicle A. The left-right direction is defined along the width direction of vehicle A. Furthermore, the up-down (see upward Ue and downward Si in FIG. 2) directions are defined along the vertical direction of the horizontal plane that defines the front-rear and left-right directions. In addition, to simplify the description, the symbols indicating each direction may be omitted as appropriate.

The perimeter monitoring sensor 30 is an autonomous sensor that monitors the environment around vehicle A. From the detection range around the vehicle, the perimeter monitoring sensor 30 can detect moving objects such as pedestrians, cyclists, non-human animals, and other vehicles, as well as fallen objects on the road, road markings such as guardrails, curbs, road signs, and lane markings, and stationary objects such as structures on the side of the road. The perimeter monitoring sensor 30 provides detection information about objects around vehicle A to the driving assistance ECU 50, etc., via the communication bus 99.

The perimeter monitoring sensor 30 has a front camera 31 and a millimeter wave radar 32 as detection components for object detection. The front camera 31 outputs at least one of image data capturing an area in front of the vehicle A and an analysis result of the image data as detection information. For example, a plurality of millimeter wave radars 32 are arranged at intervals on each of the front and rear bumpers of the vehicle A. The millimeter wave radar 32 irradiates millimeter waves or quasi-millimeter waves toward the front area, front side area, rear area, rear side area, etc. of the vehicle A. The millimeter wave radar 32 generates detection information by processing the reception of reflected waves reflected by moving objects, stationary objects, etc. Note that detection components such as lidar and sonar may be included in the perimeter monitoring sensor 30.

The locator 40 generates highly accurate position information of the vehicle A by composite positioning that combines multiple pieces of acquired information. For example, the locator 40 can identify one lane in which the vehicle A is traveling on a road that includes multiple lanes. The locator 40 includes a GNSS (Global Navigation Satellite System) receiver 41, an inertial sensor 42, a high-precision map database (hereinafter, high-precision map DB) 43, and a locator ECU 44.

The GNSS receiver 41 receives positioning signals transmitted from multiple artificial satellites (positioning satellites). The GNSS receiver 41 can receive positioning signals from each positioning satellite of at least one satellite positioning system, such as GPS, GLONASS, Galileo, IRNSS, QZSS, and Beidou. The inertial sensor 42 has, for example, a gyro sensor and an acceleration sensor.

The high-precision map DB 43 is mainly composed of non-volatile memory, and stores map data (hereinafter, high-precision map data) that is more accurate than the map data used by the navigation device 52. The high-precision map data holds detailed information at least in the height (z) direction. The high-precision map data includes information that can be used for advanced driving assistance or automated driving, such as three-dimensional shape information of roads, information on the number of lanes, and information indicating the driving direction permitted for each lane. The high-precision map data is updated to the latest content by the communication function of an on-board communication device such as a DCM (Data Communication Module).

The locator ECU 44 is mainly composed of a microcontroller equipped with a processor, RAM, a storage unit, an input/output interface, and a bus connecting these. The locator ECU 44 combines the positioning signal received by the GNSS receiver 41, the measurement results of the inertial sensor 42, and the vehicle speed information output to the communication bus 99, and sequentially measures the position and traveling direction of the vehicle A. The locator ECU 44 provides the position information and direction information of the vehicle A based on the positioning results (hereinafter, locator information) to the navigation device 52, the HCU 100, the driving assistance ECU 50, etc., via the communication bus 99. In addition, the locator ECU 44 provides high-precision map data read from the high-precision map DB 43 to the requesting ECU in response to a request from the HCU 100, the driving assistance ECU 50, etc.

The driving assistance ECU 50 is an in-vehicle computer that mainly includes a control circuit equipped with a processor, RAM, a memory unit, an input/output interface, and a bus connecting these. The driving assistance ECU 50, together with the HCU 100, constitutes an in-vehicle system that executes most of the calculations related to vehicle control. The driving assistance ECU 50 is equipped with a driving assistance function that assists the driver in driving operations. As an example, the driving assistance ECU 50 enables partial autonomous driving control (advanced driving assistance) of level 2 or lower in the autonomous driving levels defined by the Society of Automotive Engineers.

The driving assistance ECU 50 has functional units such as an environment recognition unit and a behavior control unit to enable driving assistance for the driver. The environment recognition unit recognizes the driving environment around the vehicle based on the detection information acquired from the surrounding monitoring sensor 30, the locator information acquired from the locator 40, high-precision map data, etc. The behavior control unit uses the recognition results of the driving environment by the environment recognition unit to control the behavior of the vehicle in cooperation with the driving control ECU, etc.

The driving assistance ECU 50 can realize driving assistance functions such as LDW, ACC, LTC, and LCA. LDW (Lane Departure Warning) is a function that issues an alarm to the driver when the vehicle is about to depart from the lane in which it is traveling. ACC (Adaptive Cruise Control) is a function that drives the vehicle at a constant speed at a target vehicle speed, or drives the vehicle following the vehicle in front while maintaining a distance from the vehicle in front. LTC (Lane Trace Control) is a function that cooperates with ACC to control the steering angle of the steering wheel of the vehicle to follow the lane in which it is traveling, and continues traveling within the road. LCA (Lane Change Assist) is a function that controls the steering angle of the steering wheel instead of LTC, and changes the lane of vehicle A from the lane in which it is traveling to an adjacent lane. The driving assistance ECU 50 provides the HCU 100 with status information indicating the operating state of each assistance function, control information indicating the control content executed by the function in operation, etc. as ADAS (Advanced Driver Assistance System) information.

The navigation device 52 is an in-vehicle device that works in conjunction with the HMI system 10 to provide route guidance to a destination set by the driver or the like. The navigation device 52 provides guidance such as going straight, turning right or left, and changing lanes in a guidance area GA (see FIG. 18, etc.) such as intersections, branching points, and merging points included in the set route by displaying guidance images and playing guidance audio. When a destination is set, the navigation device 52 provides navigation information related to route guidance to the HCU 100. The navigation information includes route information to the destination and a guidance implementation request that instructs the start of the above guidance. The guidance implementation request is output from the navigation device 52 to the HCU 100, for example, when the remaining distance to the guidance area GA becomes less than a predetermined value.

In addition, instead of the navigation device 52, a user terminal such as a smartphone may be connected to the in-vehicle network 1 or the HCU 100. In an application (e.g., a map application or a navigation application) executed on the user terminal, a route to the destination is set based on a user operation such as a driver. The user terminal, like the navigation device 52, performs route guidance in the guidance area GA and provides navigation information to the HCU 100.

The steering ECU 61 is an ECU provided in the steering control system of the vehicle A, and is mainly composed of a microcontroller. The steering ECU 61 controls the operation of the steering actuator based on at least one of the steering operation by the driver and the control command obtained from the driving assistance ECU 50, and determines the direction of the steered wheels and, ultimately, the traveling direction of the vehicle A. The steering ECU 61 provides the driving assistance ECU 50, the HCU 100, etc. with operation information (steering information) indicating the rotation direction and rotation angle (steering wheel angle) of the steering wheel detected by the steering angle sensor 62. The steering information may be the steering direction and actual steering angle of the steering wheels.

The body ECU 63 is a control device that mainly includes a microcontroller. The body ECU 63 has at least the function of controlling the operation of the lighting devices mounted on the vehicle A. A direction indicator switch 64 is electrically connected to the body ECU 63. The direction indicator switch 64 is a lever-shaped operating unit provided on the steering column unit 8. Based on the detection of a user operation input to the direction indicator switch 64, the body ECU 63 starts flashing either the left or right direction indicator corresponding to the operation direction.

In addition to the normal user operation to start the blinking of the direction indicator, an ON operation to start the LCA is input to the direction indicator switch 64. As an example, a user operation to half-press the direction indicator switch 64 for a predetermined time (e.g., about 1 to 3 seconds) while the LTC is activated is considered to be an ON operation of the LCA. When a user operation is input to the direction indicator switch 64, the body ECU 63 provides operation information (blinker information) indicating the content of the user operation to the driving assistance ECU 50, the HCU 100, etc.

Next, we will explain the details of the operation device 26, DSM 27, HUD 20, and HCU 100 included in the HMI system 10 in order.

The operation device 26 is an input unit that accepts user operations by the driver, etc. User operations for switching between starting and stopping a driving assistance function and an automatic driving function, for example, are input to the operation device 26. Specifically, the operation device 26 includes a steering switch provided on the spokes of the steering wheel, an operation lever provided on the steering column 8, and a voice input device that detects the driver's speech.

The DSM 27 includes a near-infrared light source, a near-infrared camera, and a control unit that controls them. The DSM 27 is installed, for example, on the top surface of the steering column 8 or the top surface of the instrument panel 9, with the near-infrared camera facing the headrest of the driver's seat. The DSM 27 uses the near-infrared camera to capture an image of the driver's head illuminated with near-infrared light from the near-infrared light source. The image captured by the near-infrared camera is analyzed by the control unit. The control unit extracts information such as the position of the eye point EP and the line of sight from the captured image, and sequentially outputs the extracted status information to the HCU 100.

The HUD 20 is mounted on the vehicle A as one of a number of in-vehicle display devices, together with a meter display and a center information display. The HUD 20 is electrically connected to the HCU 100 and sequentially acquires image data generated by the HCU 100. Based on the image data, the HUD 20 presents various information related to the vehicle A to the driver using a virtual image Vi.

The HUD 20 is housed in a storage space within the instrument panel 9, below the windshield WS. The HUD 20 projects light that is focused as a virtual image Vi toward the projection range PA of the windshield WS. The light projected onto the windshield WS is reflected in the projection range PA toward the driver's seat and perceived by the driver. The driver visually recognizes a display in which the virtual image Vi is superimposed on the foreground seen through the projection range PA.

The HUD 20 includes a projector 21 and a magnifying optical system 22. The projector 21 has an LCD (Liquid Crystal Display) panel and a backlight. The projector 21 is fixed to the housing of the HUD 20 with the display surface of the LCD panel facing the magnifying optical system 22. The projector 21 displays each frame image of the video data on the display surface of the LCD panel, and emits light that is focused as a virtual image Vi toward the magnifying optical system 22 by transmitting and illuminating the display surface with a backlight. The magnifying optical system 22 includes at least one optical element such as a concave mirror. The magnifying optical system 22 projects the light emitted from the projector 21 into an upper projection range PA while expanding it by reflection.

The above HUD 20 has a field angle VA set. If the virtual range in space in which the HUD 20 can form a virtual image Vi is the imaging plane IS, the field angle VA is a viewing angle defined based on a virtual line connecting the driver's eye point EP and the outer edge of the imaging plane IS. The field angle VA is the angle range in which the driver can view the virtual image Vi from the eye point EP. In the HUD 20, the horizontal field angle in the horizontal direction (e.g., about 10 to 12 degrees) is larger than the vertical field angle in the vertical direction (e.g., about 4 to 5 degrees). When viewed from the eye point EP, the forward range that overlaps with the imaging plane IS (e.g., a range of about 10 to 100 meters) is within the field angle VA.

The HUD 20 can display the superimposed content CTs (see Figures 4 to 6, etc.) and non-superimposed content as a virtual image Vi. The superimposed content CTs is an AR display object used for Augmented Reality (AR) display. The display position of the superimposed content CTs is associated with a specific superimposed object in the foreground, such as a specific position on the road surface, a vehicle ahead, a pedestrian, or a road sign. The superimposed content CTs is displayed superimposed on a specific superimposed object in the foreground, and can move as seen by the driver, following the superimposed object, as if fixed relative to the superimposed object. In other words, the relative positional relationship between the driver's eye point EP, the superimposed object in the foreground, and the superimposed content CTs is continuously maintained. Therefore, the shape of the superimposed content CTs is updated at a predetermined interval according to the relative position and shape of the superimposed object. The superimposed content CTs is displayed in a more horizontal orientation than the non-superimposed content, and is displayed in a shape that extends in the depth direction as seen by the driver, for example.

Non-overlapping content is a non-AR display object that is displayed in a superimposed manner in the foreground, excluding the superimposed content CTs. Unlike the superimposed content CTs, the non-overlapping content is displayed in a superimposed manner in the foreground without a specific superimposed object being specified. The display position of the non-overlapping content is not associated with a specific superimposed object. The display position of the non-overlapping content is a fixed position within the projection range PA (the above-mentioned angle of view VA). Therefore, the non-overlapping content is displayed as if it is fixed relative to the vehicle configuration such as the windshield WS. In addition, the shape of the non-overlapping content is made substantially constant. Note that due to the positional relationship between the vehicle A and the superimposed object, there may be scenes in which even the non-overlapping content is displayed overlapping with the superimposed object of the superimposed content CTs.

The HCU 100 is an electronic control device that comprehensively controls the display of multiple in-vehicle display devices, including the HUD 20, in the HMI system 10. The HCU 100 and the HUD 20 constitute a virtual image display system.

The HCU 100 is mainly composed of a computer including a processing unit 11, a RAM 12, a storage unit 13, an input/output interface 14, and a bus connecting these. The processing unit 11 is hardware for arithmetic processing coupled to the RAM 12. The processing unit 11 is composed of at least one arithmetic core such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The processing unit 11 may further include an FPGA (Field-Programmable Gate Array), an NPU (Neural network Processing Unit), and an IP core with other dedicated functions. The RAM 12 may be composed of a video RAM for image generation. The processing unit 11 accesses the RAM 12 to execute various processes for realizing the functions of each functional unit described later. The storage unit 13 is composed of a non-volatile storage medium. The storage unit 13 stores various programs (display control programs, etc.) executed by the processing unit 11.

The HCU 100 has multiple functional units for controlling the display of the virtual image Vi by the HUD 20 by executing a display control program stored in the memory unit 13 using the processing unit 11. Specifically, the HCU 100 has functional units such as a viewpoint position identification unit 71, an information acquisition unit 72, a scene determination unit 73, and a display generation unit 76.

The viewpoint position identification unit 71 identifies the position of the eye point EP of the driver seated in the driver's seat based on the status information acquired from the DSM 27. The viewpoint position identification unit 71 generates three-dimensional coordinates (hereinafter, eye point coordinates) indicating the position of the eye point EP, and sequentially provides the generated eye point coordinates to the display generation unit 76.

The information acquisition unit 72 acquires various information required for display by the in-vehicle display device through the communication bus 99. Specifically, the information acquisition unit 72 acquires locator information and high-precision map data of the surroundings of the vehicle from the locator 40, acquires ADAS information from the driving assistance ECU 50, and acquires navigation information from the navigation device 52. The information acquisition unit 72 also acquires operation information from the steering ECU 61 and the body ECU 63. Note that the information acquisition unit 72 may acquire at least one of the image data of the front camera 31 and the detection information of the surrounding monitoring sensor 30 as information equivalent to a portion of the ADAS information. Furthermore, if the information acquisition unit 72 cannot acquire high-precision map data from the locator 40, it may acquire alternative navigation map data from the navigation device 52.

The scene determination unit 73 determines the current driving scene of the vehicle A based on various information acquired by the information acquisition unit 72. The scene determination unit 73 has a function of determining whether the current driving scene is a predetermined reverse driving scene (hereinafter, the predetermined reverse driving scene SnX). The predetermined reverse driving scene SnX is a driving scene that is assumed in advance in relation to reverse driving of the vehicle A. The determination of whether the scene is a predetermined reverse driving scene SnX or not performed by the scene determination unit 73 includes a first scene determination that determines whether the scene is a first reverse driving scene Sn1 and a second scene determination that determines whether the scene is a second reverse driving scene Sn2. The first reverse driving scene Sn1 is a driving scene in which the vehicle A is likely to drive in the wrong direction, and is not currently driving in the wrong direction, but is a driving scene in which reverse driving is highly likely to occur if the driving state continues as it is. On the other hand, the second reverse driving scene Sn2 is a driving scene in which the vehicle A is actually driving in the wrong direction.

The scene determination unit 73 performs the first scene determination and the second scene determination based on the locator information, the high-precision map data, and the operation information related to the operation of the driver who drives the vehicle A. More specifically, the scene determination unit 73 determines the correct driving direction of each of the multiple lanes included in the road on which the vehicle A is currently traveling based on the locator information and the high-precision map data. Furthermore, the scene determination unit 73 identifies the lane on which the vehicle A is currently traveling among the multiple lanes, and determines whether the current driving direction of the vehicle A, which is also based on the locator information, is consistent with the driving direction specified for the lane on which the vehicle A is traveling (second scene determination). If the driving direction of the vehicle A differs from the driving direction specified for the lane on which the vehicle A is traveling, the scene determination unit 73 determines that the vehicle A is traveling in the oncoming lane Lnw and that the current driving scene is the second reverse driving scene Sn2.

Here, the scene determination unit 73 may perform a second scene determination by image analysis of the image data captured by the front camera 31. As an example, the scene determination unit 73 recognizes road signs on the side of the road and road markings laid on the road surface from the image data captured by the front camera 31. The scene determination unit 73 can estimate that the vehicle A is traveling in the oncoming lane Lnw based on the fact that the back side of the road sign is captured and the road markings are facing in the opposite direction.

The process of determining whether vehicle A is traveling in the oncoming lane Lnw based on the locator information and high-precision map data may be performed by the locator ECU 44 or the driving assistance ECU 50. Similarly, the process of determining whether vehicle A is traveling in the oncoming lane Lnw based on the image data of the front camera 31 may be performed by the driving assistance ECU 50. In these embodiments, the scene determination unit 73 performs the second scene determination by referring to the determination results provided to the information acquisition unit 72 from each ECU 44, 50.

On the other hand, if the driving direction of vehicle A matches the driving direction specified for the lane in which vehicle A is traveling, the scene determination unit 73 determines that vehicle A is traveling in the correct lane (hereinafter, driving lane Lnc). In this case, the scene determination unit 73 further determines whether or not the driving lane Lnc is adjacent to the oncoming lane Lnw. If the driving direction specified for the adjacent lane is opposite to the driving direction of the driving lane Lnc, the scene determination unit 73 determines that the driving lane Lnc is adjacent to the oncoming lane Lnw. In this case, the scene determination unit 73 performs a first scene determination to detect a sign or symptom of wrong-way driving.

Specifically, in the first scene determination, the scene determination unit 73 determines whether or not the driver is performing a driving operation to move toward the oncoming lane Lnw based on the driver's operation information. As an example, driving operations such as a turn signal operation toward the oncoming lane Lnw, an LCA activation operation, and a steering operation (hereinafter, reverse-running precursor operations) are used in the first scene determination. If a reverse-running precursor operation has been performed, the scene determination unit 73 determines that the current driving scene is the first reverse-running scene Sn1.

In addition, the scene determination unit 73 further has a function of determining the presence or absence of an obstacle (hereinafter, a division object Ob, see FIG. 7) installed on the center line CL in relation to the function of determining the predetermined reverse driving scene SnX. The center line CL is a division line that divides the lane Lnc in which the vehicle A is traveling and the oncoming lane Lnw adjacent to the lane Lnc. The scene determination unit 73 determines that a division object Ob is present when a three-dimensional object that prevents movement to the oncoming lane Lnw, such as a pole, a fence, or a block, is installed on the center line CL. The scene determination unit 73 may perform image processing to recognize the division object Ob shown in the captured data, or may obtain detection information indicating the presence of the division object Ob from the surroundings monitoring sensor 30. Furthermore, the scene determination unit 73 may grasp the presence of the division object Ob from at least one of the results of the environment recognition by the driving assistance ECU 50 and the high-precision map data.

The display generation unit 76 controls the presentation of information to the driver by the HUD 20 by generating video data that is sequentially output to the HUD 20. The display generation unit 76 draws the original image of each content displayed as a virtual image Vi in each frame image that constitutes the video data. When drawing the original image of the superimposed content CTs (see FIG. 4, etc.) in the frame image, the display generation unit 76 corrects the drawing position and drawing shape of the original image in the frame image according to the eye point EP and each position of the superimposition target. As a result, the superimposed content CTs is displayed in a position and shape that is correctly superimposed on the superimposition target when viewed from the eye point EP.

The display generation unit 76 has a content selection function and a virtual layout function to realize the generation of the above-mentioned video data. The content selection function is a function for selecting content to be used for information presentation from among a plurality of superimposed contents CTs and a plurality of non-superimposed contents prepared in advance. The display generation unit 76 selects content to be drawn on the video data based on various information acquired by the information acquisition unit 72 and the judgment result of the scene judgment unit 73. For example, when a guidance implementation request (navigation information) is acquired by the information acquisition unit 72, the display generation unit 76 selects superimposed content CTs such as an arrow shape that performs route guidance (see route guidance content CTnv in FIG. 19) as a drawing target on the video data. In addition, when status information (ADAS information) indicating the start of operation of driving assistance functions such as LDW, ACC, LTC, and LKA is acquired, the display generation unit 76 selects superimposed content CTs (driving assistance content) linked to each driving assistance function as a drawing target on the video data. Furthermore, if the scene determination unit 73 determines that the scene is a predetermined reverse driving scene SnX, the display generation unit 76 selects the reverse driving prevention content CTp (see Figures 4 to 6) as the subject to be rendered in the video data.

The virtual layout function is a function that simulates the display layout of the superimposed content CTs based on various information provided to the display generation unit 76. When a display including the superimposed content CTs is selected by the content selection function, the display generation unit 76 reproduces the current driving environment of vehicle A in a virtual space based on locator information, high-precision map data, detection information, etc. Note that when high-precision map data cannot be obtained, the display generation unit 76 may use navigation map data instead of high-precision map data.

In more detail, the display generation unit 76 places the vehicle object at a reference position in the virtual three-dimensional space, and maps a road model based on high-precision map data in the three-dimensional space in association with the vehicle object. In addition, the display generation unit 76 sets a virtual camera position corresponding to the driver's eye point EP in association with the vehicle object. The display generation unit 76 sequentially corrects the virtual camera position relative to the vehicle object based on the latest eye point coordinates acquired by the viewpoint position identification unit 71. Based on the virtual camera position and the outer edge position (coordinate) information of the imaging surface IS stored in advance in the storage unit 13, the display generation unit 76 determines the forward range inside the imaging surface IS when looking forward from the virtual camera position as the superimposition range in which the superimposition content CTs can be superimposed and displayed. This superimposition range is within the angle of view VA when viewed from the eye point EP.

The display generation unit 76 places a virtual object corresponding to the superimposed content CTs selected as the drawing target on the road surface of the road model in three-dimensional space. The display generation unit 76 determines the drawing shape of the original image of the superimposed content CTs to be drawn on the video data by a calculation process that projects the virtual object onto the imaging plane IS along a virtual projection line connecting the virtual camera position and the virtual object. As a result, the shape of the virtual object as viewed from the virtual camera position becomes the virtual image shape of the superimposed content CTs viewed from the eye point EP.

As described above, when a specific reverse driving scene SnX occurs, the display generation unit 76 causes the HUD 20 to display reverse driving prevention content CTp as shown in Figures 4 to 6 superimposed on the road surface in the foreground. The reverse driving prevention content CTp is superimposed content CTs that is displayed for the purpose of preventing vehicle A from driving in the wrong direction, and guides vehicle A to drive in the correct driving lane Lnc. The display generation unit 76 displays the first reverse driving prevention content CTp1 (see Figures 4 and 5) and the second reverse driving prevention content CTp2 (see Figure 6) as the reverse driving prevention content CTp.

The first reverse-running prevention content CTp1 guides vehicle A to travel in the correct lane Lnc by issuing a warning against the driver attempting to change lanes to an adjacent lane (oncoming lane Lnw). The first reverse-running prevention content CTp1 starts to be displayed when the first scene determination by the scene determination unit 73 determines that the scene is the first reverse-running scene Sn1. The first reverse-running prevention content CTp1 continues to be displayed until a predetermined time has elapsed from the start of display, or until the driver's reverse-running precursor operation that caused the determination that the scene is the first reverse-running scene Sn1 is resolved.

The display generation unit 76 changes the content of the first reverse driving prevention content CTp1 (reverse driving prevention content CTp) according to the operation content of the reverse driving precursor operation indicated by the operation information. In detail, the display generation unit 76 starts displaying the first reverse driving prevention content CTp1 shown in FIG. 4 based on the ON operation of the direction indicator (direction indication switch 64), which is a reverse driving precursor operation. The first reverse driving prevention content CTp1 displayed at this time includes a virtual barrier CTb.

The virtual barrier CTb is displayed superimposed on the road surface of the driving lane Lnc. The virtual barrier CTb is erected substantially vertically upward from the road surface of the driving lane Lnc, and is drawn in the shape of a wall extending along the center line CL in the traveling direction of the host vehicle. This display shape creates a visual effect of preventing the host vehicle from changing lanes into the oncoming lane Lnw. The virtual barrier CTb is displayed as if it is fixed to the road surface, and moves backward (downward and to the side) within the field of view VA together with the road surface in the foreground as the host vehicle travels.

If the driver performs a steering operation that brings the vehicle A closer to the center line CL despite the display of the virtual barrier CTb, the display generation unit 76 starts displaying the first reverse-running prevention content CTp1 in an emphasized form as shown in FIG. 5 based on the steering operation that is a reverse-running predictive operation. The first reverse-running prevention content CTp1 displayed at this time includes the virtual oncoming vehicle CTc.

The virtual oncoming vehicle CTc is displayed in place of the virtual barrier CTb (see FIG. 4). The virtual oncoming vehicle CTc is superimposed on the road surface of the oncoming lane Lnw. The virtual oncoming vehicle CTc is a display object that imitates a vehicle seen from the front side. The virtual oncoming vehicle CTc passes through the viewing angle VA faster than the road surface of the oncoming lane Lnw, creating a visual effect that makes it appear as if an oncoming vehicle is traveling in the oncoming lane Lnw. Due to the display of the virtual oncoming vehicle CTc moving faster than the virtual barrier CTb, the first reverse running prevention content CTp1 displayed based on the steering operation is emphasized more than the first reverse running prevention content CTp1 displayed based on the turn signal being turned on. The animation of the virtual oncoming vehicle CTc passing through the viewing angle VA is displayed repeatedly at a predetermined cycle until the display of the first reverse running prevention content CTp1 ends.

Here, the superimposed content CTs similar to the virtual barrier CTb shown in FIG. 4 may be displayed as a driving support content linked to, for example, an LDW. However, the driving support content linked to the LDW is displayed only when the vehicle is in a driving state where it is likely to cross the lane marking based on the relative distance and relative angle to the lane marking of the vehicle, regardless of whether there is an oncoming lane Lnw in the direction of movement of the vehicle. In contrast, the first reverse running prevention content CTp1 is displayed based on a reverse running prediction operation only when there is an oncoming lane Lnw in the direction of movement of the vehicle. At this time, the relative distance and relative angle of the vehicle to the center line CL, in other words, whether the vehicle is in a driving state where it is likely to cross the center line CL, is not substantially taken into consideration. In other words, while the driving support content linked to the LDW is a content that issues a warning based on the driving state, the first reverse running prevention content CTp1 is a content that issues a warning based on driving operation. As described above, there is an essential difference in the display start conditions between the first reverse driving prevention content CTp1 and the driving assistance content linked to the LDW, etc.

The second reverse-running prevention content CTp2 shown in FIG. 6 guides the driver to change lanes to the lane Lnc in which vehicle A should be running by making the driver aware that the lane in which the vehicle is running is the oncoming lane Lnw. The second reverse-running prevention content CTp2 starts to be displayed when the second scene determination determines that the scene is the second reverse-running scene Sn2. At least a portion of the second reverse-running prevention content CTp2 is superimposed on the road surface of the lane Lnc in which vehicle A should be running. The second reverse-running prevention content CTp2 continues to be displayed until vehicle A returns to the correct lane Lnc.

After displaying the first reverse driving prevention content CTp1 (see FIG. 5), if the driving scene of vehicle A transitions from the first reverse driving scene Sn1 to the second reverse driving scene Sn2, the display generation unit 76 changes the mode of the reverse driving prevention content CTp. That is, the display generation unit 76 displays the second reverse driving prevention content CTp2 in a different mode from the first reverse driving prevention content CTp1 displayed in the first reverse driving scene Sn1. This second reverse driving prevention content CTp2 includes virtual guiding paint CTg.

The virtual guiding paint CTg is displayed in a shape that crosses the center line CL diagonally, overlapping both the road surface on the vehicle's side of the oncoming lane Lnw and the road surface on the far side of the driving lane Lnc. The virtual guiding paint CTg is a drawing shape that evokes the driving path of the vehicle when changing lanes from the oncoming lane Lnw to the correct driving lane Lnc. It is desirable that the virtual guiding paint CTg has a shape that is unlikely to overlap with a distant oncoming vehicle TA traveling in the oncoming lane Lnw. The virtual guiding paint CTg is displayed in a display color that is more conspicuous than the virtual barrier CTb (see FIG. 4) and the virtual oncoming vehicle CTc (see FIG. 5). For example, the virtual guiding paint CTg is displayed with a higher brightness or saturation than the virtual barrier CTb and the virtual oncoming vehicle CTc. The virtual guiding paint CTg is displayed as an animation that repeatedly extends from the vehicle's side (the lower edge of the viewing angle VA) toward the rear side (the upper edge of the viewing angle VA). The animation of the virtual guiding paint CTg extending in the direction of travel within the viewing angle VA is displayed repeatedly at a predetermined cycle until the display of the second reverse driving prevention content CTp2 ends.

When the scene determination unit 73 determines that the partition object Ob exists, the display generation unit 76 suspends the superimposed display of the reverse driving prevention content CTp (first reverse driving prevention content CTp1) by the HUD 20 as shown in FIG. 7. However, even during the period when the display of the reverse driving prevention content CTp is suspended, the scene determination unit 73 continues to determine whether or not it is a specified reverse driving scene SnX. Furthermore, the display generation unit 76 continues to prepare the drawing data of the reverse driving prevention content CTp even during the period when the display of the reverse driving prevention content CTp is suspended. The preparation of the drawing data is a process of determining the drawing shape of the original image of the reverse driving prevention content CTp. The display generation unit 76 generates the original image of the reverse driving prevention content CTp while stopping the process of drawing the generated original image in the video data, thereby temporarily suspending the superimposed display of the reverse driving prevention content CTp.

Next, the details of the display control method for displaying the reverse driving prevention content CTp will be described below with reference to the flowcharts shown in Figures 8 and 9 and with reference to Figures 1 to 7. The mode switching process shown in Figure 8 and the content display process shown in Figure 9 are repeatedly started by the HCU 100 that has completed the startup process, for example, by switching the vehicle power supply to the on state.

In S11 of the mode switching process shown in FIG. 8, the presence or absence of a partition object Ob is determined. If it is determined in S11 that a partition object Ob is not present, the process proceeds to S12. In S12, the display setting of the reverse driving prevention content CTp is set to a display permission mode in which superimposed display of the reverse driving prevention content CTp is permitted, and the mode switching process ends.

On the other hand, if it is determined in S11 that a section object Ob is present, the process proceeds to S13. In S13, the display setting of the reverse driving prevention content CTp is set to a display prohibition mode that prohibits the superimposed display of the reverse driving prevention content CTp, and the mode switching process ends. This setting in S13 interrupts the superimposed display of the reverse driving prevention content CTp (virtual barrier CTb) that would overlap the section object Ob. Note that regardless of the display setting of the reverse driving prevention content CTp by the mode switching process, the content display process described below continues.

In S101 of the content display process shown in FIG. 9, it is determined whether the current driving scene is the first reverse driving scene Sn1 (first scene determination). If it is determined in S101 that the scene is not the first reverse driving scene Sn1, the process proceeds to S104. On the other hand, if it is determined in S101 that the scene is the first reverse driving scene Sn1, the process proceeds to S102. In S102, display control is performed to display the first reverse driving prevention content CTp1, and the process proceeds to S103.

In the display control of S102, the display setting of the reverse driving prevention content CTp by the mode switching process is referenced. If the display setting is the display permission mode, S102 displays the first reverse driving prevention content CTp1 according to the content of the reverse driving warning operation. On the other hand, if the display setting is the display prohibition mode, S102 goes as far as preparing the drawing data of the first reverse driving prevention content CTp1 according to the content of the reverse driving warning operation.

In S103, it is determined whether the display end condition of the first reverse driving prevention content CTp1 is satisfied. As described above, the display end condition of the first reverse driving prevention content CTp1 is that a predetermined time has passed since the start of display, or that the reverse driving warning operation has been resolved, etc. In addition, the display end condition is satisfied when the driving scene of the host vehicle transitions from the first reverse driving scene Sn1 to the second reverse driving scene Sn2. As an example, when at least a part of the vehicle A is positioned on the center line CL, or when a part of the vehicle A protrudes from the driving lane Lnc into the oncoming lane Lnw, the result of the scene determination transitions from the first reverse driving scene Sn1 to the second reverse driving scene Sn2.

If it is determined in S103 that the display end condition of the first reverse driving prevention content CTp1 is not satisfied, the process returns to S102. As a result, the display of the first reverse driving prevention content CTp1 continues. On the other hand, if it is determined in S103 that the display end condition of the first reverse driving prevention content CTp1 is satisfied, the process proceeds to S104.

In S104, it is determined whether the current driving scene is the second reverse driving scene Sn2 or not (second scene determination). If it is determined in S104 that the scene is not the second reverse driving scene Sn2, the process proceeds to S107. On the other hand, if it is determined in S104 that the scene is the second reverse driving scene Sn2, the process proceeds to S105. In S105, display control is performed to display the second reverse driving prevention content CTp2, and the process proceeds to S106. In the display control in S105, the display setting of the reverse driving prevention content CTp by the mode switching process is not referenced.

In S106, it is determined whether the display end condition of the second reverse driving prevention content CTp2 is satisfied. As described above, the display end condition of the second reverse driving prevention content CTp2 is that the vehicle A has returned to the correct driving lane Lnc. For example, when the entire vehicle A moves toward the driving lane Lnc side from the center line CL, the display end condition of the second reverse driving prevention content CTp2 is satisfied. If it is determined in S106 that the display end condition is not satisfied, the process returns to S105. As a result, the display of the second reverse driving prevention content CTp2 continues. On the other hand, if it is determined in S106 that the display end condition of the second reverse driving prevention content CTp2 is satisfied, the process proceeds to S107. In S107, the display of the reverse driving prevention content CTp that started to be displayed in S102 or S105 is terminated, and the content display process is terminated.

In the first embodiment described so far, when the driving scene of vehicle A is determined to be a predetermined reverse driving scene SnX, reverse driving prevention content CTp, which guides the vehicle to drive in the correct driving lane Lnc, is superimposed on the road surface in the foreground by the HUD 20. This makes it easier for the driver to grasp information such as the lane in which the vehicle is currently driving and where the vehicle should be driving. In this way, detailed information related to reverse driving is clearly shown by the superimposed display of reverse driving prevention content CTp, thereby making it possible to increase convenience for the driver.

In addition, in the first embodiment, the determination of whether or not a specific reverse driving scene SnX occurs includes not only the second scene determination of whether or not a second reverse driving scene Sn2 in which vehicle A is driving in the wrong direction, but also the first scene determination of whether or not a first reverse driving scene Sn1 in which vehicle A is likely to drive in the wrong direction. As a result, it becomes possible to display the first reverse driving prevention content CTp1 based on the first scene determination before vehicle A actually drives in the wrong direction. As a result, the occurrence of reverse driving can be prevented in advance.

In the first embodiment, whether or not a first reverse driving scene Sn1 has occurred is determined based on operation information related to the operation of the driver driving vehicle A. In this way, based on the driver's operation information, it is possible to detect early signs of driving operations that may lead to the vehicle erroneously heading into the oncoming lane Lnw. As a result, it becomes easier to achieve the effect of preventing reverse driving from occurring.

Furthermore, in the first embodiment, when it is determined that the first reverse driving scene Sn1 has occurred, the content of the reverse driving prevention content CTp (first reverse driving prevention content CTp1) changes according to the operation content of the driver indicated by the operation information. In this way, by associating the operation content of the driver with the content of the reverse driving prevention content CTp, the reverse driving prevention content CTp can repeatedly alert the driver to the input operation error if the driver continues to perform an incorrect operation. As a result, the effect of preventing reverse driving from occurring is further improved.

Specifically, in the first embodiment, the display of the first reverse-running prevention content CTp1 begins based on the turning-on operation of the direction indicator switch 64 (see FIG. 4). Then, based on the steering operation that brings the vehicle A closer to the center line CL, which is the boundary between the driving lane Lnc and the oncoming lane Lnw, the first reverse-running prevention content CTp1 changes to an emphasized state (see FIG. 5). As described above, if the emphasis of the first reverse-running prevention content CTp1 is changed in accordance with the increasing risk of reverse running, the driver will be more likely to notice that he or she is making a mistake that could lead to reverse running.

In the first embodiment, when the first reverse driving scene Sn1 transitions to the second reverse driving scene Sn2, the second reverse driving prevention content CTp2, which is different from the first reverse driving prevention content CTp1 displayed in the first reverse driving scene Sn1, is displayed. In this way, if a display switch is implemented to change the state of the reverse driving prevention content CTp in accordance with the transition of the specified reverse driving scene SnX, the driver can easily notice the reverse driving state of his or her vehicle.

In addition, according to the first embodiment, the first reverse-driving prevention content CTp1 continues to be displayed until a predetermined time has elapsed from the start of display, or until the driver's reverse-driving predictive operation that caused the determination that the first reverse-driving scene Sn1 occurred is resolved. As a result, the first reverse-driving prevention content CTp1 displayed in the first reverse-driving scene Sn1 is hidden before it becomes annoying to the driver, while still appropriately alerting the driver.

On the other hand, if it is determined that the scene is the second reverse driving scene Sn2, the second reverse driving prevention content CTp2 continues to be displayed until vehicle A returns to the correct driving lane Lnc. In this way, the display end condition for the second reverse driving scene Sn2 is different from the display end condition for the first reverse driving scene Sn1, and the display is less likely to end under these conditions. As a result, the second reverse driving prevention content CTp2 is displayed indefinitely while the vehicle is driving in the wrong direction, and can continue to notify the driver of the correct driving lane Lnc until the vehicle returns to the correct driving lane Lnc.

Furthermore, in the first embodiment, at least a portion of the second reverse driving prevention content CTp2 displayed in the second reverse driving scene Sn2 is superimposed on the road surface of the driving lane Lnc in which the vehicle should be traveling. With this display form, the second reverse driving prevention content CTp2 can clearly inform the driver of the correct driving lane Lnc in which the vehicle should be returned.

In addition, in the first embodiment, the presence or absence of a partition object Ob existing between the driving lane Lnc and the oncoming lane Lnw is determined, and if such a partition object Ob exists, the superimposed display of the reverse driving prevention content CTp by the HUD 20 is interrupted. This display process prevents the reverse driving prevention content CTp from being displayed in a scene where reverse driving does not actually occur. As a result, the reverse driving prevention content CTp is less likely to be perceived as an annoyance by the driver.

In the first embodiment, even if a partition target Ob is present, the determination of whether or not a specific reverse driving scene SnX occurs is continued. By continuing the scene determination in this manner, it becomes possible to, for example, issue a warning about reverse driving using an in-vehicle display device other than the HUD 20.

Furthermore, the display generation unit 76 of the first embodiment continues to prepare drawing data for the reverse driving prevention content CTp during the period in which it is determined that the specified reverse driving scene SnX exists, even if the section marker Ob exists. As described above, by continuing the drawing process in the background, it becomes difficult to delay the start of displaying the reverse driving prevention content CTp in the specified reverse driving scene SnX after the section marker Ob no longer exists.

In the first embodiment, the section target Ob corresponds to an "obstacle", the display generation unit 76 corresponds to a "display control unit", and the HCU 100 corresponds to a "display control device".

Second Embodiment
The second embodiment of the present disclosure shown in Figures 10 and 11 is a modified example of the first embodiment. In the second embodiment, the aspects of the first reverse-running prevention content CTp1 and the second reverse-running prevention content CTp2 are different from those of the first embodiment. Hereinafter, the details of the first reverse-running prevention content CTp1 and the second reverse-running prevention content CTp2 of the second embodiment will be described based on Figures 10 and 11 and with reference to Figure 3.

The first reverse driving prevention content CTp1 shown in FIG. 10 includes a route display paint CTk. The route display paint CTk is displayed superimposed on the road surface of the driving lane Lnc in such a manner that the entire road surface of the driving lane Lnc between the left and right dividing lines is filled in. The drawing shape of the route display paint CTk changes sequentially according to the shape of the driving lane Lnc. In the second embodiment, even if the operation content of the reverse driving warning operation changes, the display content of the first reverse driving prevention content CTp1 does not substantially change. That is, the display of the route display paint CTk continues regardless of the type of reverse driving warning operation.

The route display paint CTk is, for example, a light green or light blue display color. The route display paint CTk is a drawing shape similar to or substantially the same as the route guidance content displayed based on the navigation information. Therefore, the route display paint CTk is a superimposed content CTs that differs from the route guidance content only in the display timing. Specifically, the route guidance content starts to be displayed when the vehicle A approaches the guidance area within a predetermined distance (e.g., 300 m). On the other hand, the route display paint CTk starts to be displayed based on the detection of a reverse driving predictive operation, regardless of the distance to the guidance area. Furthermore, even if a destination is not set in the navigation device 52, the route display paint CTk starts to be displayed based on the detection of a reverse driving predictive operation. As described above, even if there is a relationship in the display shape, there is an essential difference in the display start conditions between the route display paint CTk and the route guidance content.

The second reverse driving prevention content CTp2 shown in FIG. 11 includes the reverse driving warning paint CTa in addition to the route display paint CTk. After the route display paint CTk starts to be displayed in the first reverse driving scene Sn1, it continues to be displayed as a display object of the second reverse driving prevention content CTp2 even after the driving scene transitions to the second reverse driving scene Sn2. The route display paint CTk continues to be superimposed on the road surface of the correct driving lane Lnc, and moves from the center to the side (upper left corner) within the field of view VA as the vehicle A moves laterally. The route display paint CTk changes to an emphasized state as the scene transitions from the first reverse driving scene Sn1 to the second reverse driving scene Sn2. The emphasis of the route display paint CTk is mainly implemented by changing the display color. Specifically, the route display paint CTk of the second reverse driving scene Sn2 is displayed in a display color that is more eye-catching (brightness or saturation) than the route display paint CTk of the first reverse driving scene Sn1. The route display paint CTk is, for example, a dark green or dark blue display color. In the second wrong-way driving scene Sn2, unlike the route guidance content, the route display paint CTk is displayed regardless of whether or not there is a guidance area, and continues to be displayed until the vehicle A returns to the correct driving lane Lnc.

The reverse driving warning paint CTa is displayed superimposed on the road surface of the oncoming lane Lnw so as not to overlap with the route display paint CTk. The reverse driving warning paint CTa includes a warning message in text such as "reverse driving" and a frame-shaped image surrounding the outer periphery of the warning message. As with the virtual guiding paint CTg of the first embodiment (see FIG. 6), the reverse driving warning paint CTa is displayed so as not to overlap with the oncoming vehicle TA traveling in the oncoming lane Lnw at a distance. The reverse driving warning paint CTa is displayed in a display color such as yellow or amber. The reverse driving warning paint CTa may be displayed continuously a predetermined distance ahead of the vehicle, or may repeatedly move backward (downward) within the field of view VA together with the road surface of the oncoming lane Lnw.

The second embodiment described so far also has the same effect as the first embodiment, and information such as the lane in which vehicle A is currently traveling and where it should be traveling is provided to the driver by the reverse driving prevention content CTp. As a result, it is possible to improve convenience for the driver.

In addition, the display generating unit 76 of the second embodiment continues to display the route display paint CTk that started in the first reverse driving scene Sn1, even when the scene transitions from the first reverse driving scene Sn1 to the second reverse driving scene Sn2. By continuing to display the route display paint CTk in this manner, the driver is continuously notified of the correct driving lane Lnc in which the vehicle should be traveling.

In the second embodiment, the appearance of the route display paint CTk in the second wrong-way driving scene Sn2 is emphasized more than in the first wrong-way driving scene Sn1. This change in appearance can further improve the function of the route display paint CTk to notify the driver of the correct driving lane Lnc. In addition, the movement of the emphasized route display paint CTk to the corner of the field of view VA makes it easier for the driver to recognize that he or she is mistakenly driving in the opposite lane Lnw.

Third Embodiment
The third embodiment of the present disclosure shown in Figures 12 and 13 is another modified example of the first embodiment. In the third embodiment, the aspects of the first reverse-running prevention content CTp1 and the second reverse-running prevention content CTp2 are also different from those of the first embodiment. Hereinafter, the details of the first reverse-running prevention content CTp1 and the second reverse-running prevention content CTp2 of the third embodiment will be described based on Figures 12 and 13 and with reference to Figure 3.

The first reverse driving prevention content CTp1 and the second reverse driving prevention content CTp2 both include a forward arrow CTf and a reverse arrow CTr. The forward arrow CTf and the reverse arrow CTr are both drawn in an arrow shape and point in different directions. The forward arrow CTf is displayed superimposed as if it were attached to the road surface of the driving lane Lnc, with the tip of the arrowhead pointing in the direction of travel to indicate the driving direction of the driving lane Lnc. The reverse arrow CTr is displayed superimposed as if it were attached to the road surface of the oncoming lane Lnw, with the tip of the arrowhead pointing behind the vehicle to indicate the driving direction of the oncoming lane Lnw.

When it is determined that the scene is the first reverse driving scene Sn1, the display generation unit 76 alternately displays the reverse direction arrow CTr and the forward direction arrow CTf as the reverse driving prevention content CTp. Specifically, the display generation unit 76 displays the reverse direction arrow CTr, then makes the reverse direction arrow CTr invisible, and then displays the forward direction arrow CTf. Furthermore, the display generation unit 76 makes the forward direction arrow CTf invisible, and then displays the reverse direction arrow CTr. The reverse direction arrow CTr is displayed as an animation flowing backward (lower corner of the angle of view VA) once or multiple times together with the road surface of the oncoming lane Lnw. Similarly, the forward direction arrow CTf is displayed as an animation flowing backward (below the angle of view VA) once or multiple times together with the road surface of the driving lane Lnc.

The reverse arrow CTr may be a display object that remains stationary at a fixed distance to the side of the vehicle and has a shape that matches the oncoming lane Lnw. Similarly, the forward arrow CTf may be a display object that remains stationary at a fixed distance in front of the vehicle and has a shape that matches the driving lane Lnc.

The display generation unit 76 continues to alternately display the reverse arrow CTr and the forward arrow CTf even when the driving scene transitions from the first reverse driving scene Sn1 to the second reverse driving scene Sn2. In the second reverse driving scene Sn2, as the vehicle A moves into the oncoming lane Lnw, the reverse arrow CTr is displayed in front of the field of view VA. Meanwhile, the forward arrow CTf is displayed in the upper corner of the field of view VA.

The display colors of the forward arrow CTf and reverse arrow CTr may be the same or different. In addition, the display colors of the forward arrow CTf and reverse arrow CTr may be the same or different in the first reverse driving scene Sn1 and the second reverse driving scene Sn2. As an example, the forward arrow CTf is displayed in light green or light blue in the first reverse driving scene Sn1, and in dark green or dark blue in the second reverse driving scene Sn2. On the other hand, the reverse arrow CTr is displayed in yellow or light amber in the first reverse driving scene Sn1, and in dark amber or red in the second reverse driving scene Sn2.

The third embodiment described so far has the same effect as the first embodiment, and detailed information related to reverse driving is clearly displayed by superimposing the reverse driving prevention content CTp. As a result, convenience for the driver is improved.

In addition, when the scene determination unit 73 determines that the scene is a predetermined reverse driving scene SnX, the display generation unit 76 of the third embodiment displays the reverse direction arrow CTr and then the forward direction arrow CTf as reverse driving prevention content CTp. In this way, the reverse direction arrow CTr and the forward direction arrow CTf are not displayed simultaneously, but are displayed in a predetermined order when the predetermined reverse driving scene SnX is detected. As described above, by clearly indicating the driving direction of the oncoming lane Lnw with the reverse direction arrow CTr, the risk of reverse driving can be clearly conveyed to the driver. Then, by hiding the reverse direction arrow CTr and clearly indicating the correct driving lane Lnc with the forward direction arrow CTf, the driver can accurately understand the lane in which the vehicle should be driving.

In the third embodiment, the reverse direction arrow CTr corresponds to "reverse direction content" and the forward direction arrow CTf corresponds to "forward direction content." Furthermore, the scene determination unit 73 in the third embodiment does not need to distinguish between the first reverse driving scene Sn1 and the second reverse driving scene Sn2. In other words, the first reverse driving prevention content CTp1 and the second reverse driving prevention content CTp2 do not need to be distinguished.

(Fourth embodiment)
14 is a modified example of the second embodiment. In the fourth embodiment, the form of the first reverse-running prevention content CTp1 displayed in the first reverse-running scene Sn1 is different from that of the second embodiment. The first reverse-running prevention content CTp1 of the fourth embodiment includes a route display paint CTk and a virtual lane marking CTl.

The route display paint CTk is drawn in an arrow shape indicating the driving direction of the driving lane Lnc, similar to the forward arrow CTf in the third embodiment (see FIG. 11). In the fourth embodiment, the route display paint CTk is drawn in a shape similar to or substantially the same as the route guidance content, similar to the second embodiment. That is, in the fourth embodiment, the route guidance content is in the shape of an arrow. The route display paint CTk may be superimposed content CTs that is attached to the road surface a certain distance ahead of the vehicle, or may be superimposed content CTs that moves within the viewing angle VA together with the road surface of the driving lane Lnc.

The virtual lane markings CTl are superimposed on the inside of the left and right lane markings, respectively, and are superimposed content CTs that extend in a thin strip along the adjacent lane markings. The pair of virtual lane markings CTl are arranged on the left and right sides of the route display paint CTk, and together with the route display paint CTk, indicate that the lane Lnc in which the vehicle is currently traveling is the lane in which the vehicle should travel. The virtual lane markings CTl may be displayed, for example, as an animation that extends repeatedly in the direction of travel. The virtual lane markings CTl, like the route display paint CTk, may have a drawing shape similar or substantially the same as the content displayed as the route guidance content. Alternatively, the virtual lane markings CTl may have a drawing shape similar or substantially the same as the driving operation content linked to the LDW or LTC.

In the fourth embodiment described so far, detailed information related to reverse driving is clearly displayed by the reverse driving prevention content CTp, which includes the route display paint CTk and the virtual lane markings CTl. As a result, the same effects as the above embodiments are achieved, and convenience for the driver is improved.

Fifth Embodiment
15 is another modified example of the second embodiment. In the fifth embodiment, the form of the first reverse-running prevention content CTp1 displayed in the first reverse-running scene Sn1 is also different from that of the second embodiment. The first reverse-running prevention content CTp1 of the fifth embodiment includes no-entry painting CTx.

The no entry paint CTx is drawn in a cross shape in a display color such as yellow or amber. Multiple no entry paint CTx are superimposed on the road surface of the oncoming lane Lnw. Multiple no entry paint CTx are arranged in a line along the center line CL with a gap between them to alert the driver that movement to the oncoming lane Lnw across the center line CL is prohibited. The no entry paint CTx may be superimposed content CTs that remains stationary on the road surface a certain distance ahead of the vehicle, or may be superimposed content CTs that moves to the lower corner of the field of view VA together with the road surface of the oncoming lane Lnw.

In the fifth embodiment described so far, the reverse driving prevention content CTp, including the no entry painting CTx, clearly shows detailed information related to reverse driving. As a result, the same effects as the above embodiments are achieved, and convenience for the driver is improved.

Sixth Embodiment
The sixth embodiment of the present disclosure shown in Figures 16 and 17 is yet another modified example of the first embodiment. The HCU 100 (see Figure 3) of the sixth embodiment suspends the superimposed display of the reverse running prevention content CTp in an overtaking scene Snp in which the vehicle overtakes an overtaking target TP. That is, in the overtaking scene Snp, even if a part or all of the vehicle protrudes into the oncoming lane Lnw, the reverse running prevention content CTp (second reverse running prevention content CTp2, see Figure 6, etc.) is not displayed. Hereinafter, the scene determination unit 73 and the display generation unit 76 of the sixth embodiment will be described in detail based on Figures 16 and 17 and with reference to Figures 1 to 3.

In addition to the first and second scene determinations described above, the scene determination unit 73 also performs a determination as to whether or not the scene is an overtaking scene Snp. In a scene in which the vehicle strays into the oncoming lane Lnw, the scene determination unit 73 uses a combination of center line CL type information and detection information around the vehicle to determine whether the scene is a wrong-way driving scene (second wrong-way driving scene Sn2, see FIG. 6, etc.) or an overtaking scene Snp using multiple methods.

The scene determination unit 73 grasps type information of the center line CL that separates the driving lane Lnc and the oncoming lane Lnw based on the high-precision map data or image data provided to the information acquisition unit 72. Specifically, the scene determination unit 73 grasps the color of the center line CL (white or yellow) and whether the center line CL is a solid line or a broken line as the type information of the center line CL. Based on the grasped type information of the center line CL, the scene determination unit 73 judges whether or not it is prohibited to run out of the current driving lane Lnc into the oncoming lane Lnw. If the host vehicle runs out of the oncoming lane Lnw where running out is not prohibited, the scene determination unit 73 judges that it is an overtaking scene Snp. On the other hand, if the host vehicle runs out of the oncoming lane Lnw where running out is prohibited, the scene determination unit 73 judges that it is not an overtaking scene Snp but a second wrong-way driving scene Sn2.

The scene determination unit 73 may be capable of grasping information as to whether or not overtaking is prohibited on the road on which the vehicle is traveling, based on the recognition results of road signs on the side of the road and road markings laid on the road surface (so-called Traffic Sign Recognition). The recognition results of the road signs and road markings may be generated by the scene determination unit 73 using the image data of the front camera 31 provided to the information acquisition unit 72, or may be generated by the driving assistance ECU 50 and provided to the information acquisition unit 72.

The scene determination unit 73 uses the detection information of the surrounding monitoring sensor 30 provided to the information acquisition unit 72 to determine whether or not there is another vehicle around the vehicle. If there are no other vehicles around the vehicle, the driver is likely to misunderstand the driving direction specified for each lane, and as a result, is more likely to drive in the wrong direction. Furthermore, if there are no other vehicles around the vehicle, there is no need to overtake. Therefore, when there are no other vehicles around the vehicle, the scene determination unit 73 prioritizes the first scene determination and the second scene determination over the determination of whether or not it is an overtaking scene Snp. In other words, even on roads where running into the oncoming lane Lnw is not prohibited, a warning is issued by the second wrong-way driving prevention content CTp2 at the time of running into the oncoming lane Lnw.

When there are other vehicles around the vehicle, the scene determination unit 73 further grasps the type, relative position, size, and movement state of the target object TP to be overtaken based on the detection information. The overtaking target TP includes vehicles ahead traveling in the same driving lane Lnc as the vehicle, motorcycles, bicycles, and parked vehicles and obstacles that are stopped with at least a part protruding into the driving lane Lnc. When there is no overtaking target TP and the vehicle protrudes into the oncoming lane Lnw, the scene determination unit 73 determines that it is a reverse driving scene (second reverse driving scene Sn2). On the other hand, when the overtaking target TP is detected ahead and the vehicle is approaching the overtaking target TP with the traveling speed of the overtaking target TP diverging from the traveling speed of the vehicle (the relative speed is large), the scene determination unit 73 determines that it is an overtaking scene Snp.

When the scene determination unit 73 determines that the scene is an overtaking scene Snp, the display generation unit 76 suspends the superimposed display of the reverse driving prevention content CTp by the HUD 20. Details of the content display process of the sixth embodiment (see FIG. 17) that can suspend the presentation of the reverse driving prevention content CTp in the overtaking scene Snp are described below.

In S201, the scene determination unit 73 determines whether or not there is another vehicle around the vehicle. In S201, both the driving lane Lnc and the oncoming lane Lnw are detected, and all other vehicles that are in front of, to the sides of, and behind the vehicle are identified. If it is determined in S201 that there are no other vehicles around the vehicle, the process proceeds to S202. In this case, the scene determination unit 73 prioritizes the first scene determination over the determination of whether or not there is an overtaking scene Snp.

In S202, the scene determination unit 73 determines whether the current driving scene is the first reverse driving scene Sn1. If it is determined in S202 that the scene is not the first reverse driving scene Sn1, the process proceeds to S206. On the other hand, if it is determined in S202 that the scene is the first reverse driving scene Sn1, the process proceeds to S203. In S203, the display generation unit 76 performs display control of the first reverse driving prevention content CTp1 (see FIG. 4, etc.) according to the content of the reverse driving precursor operation, and the process proceeds to S204.

In S204, the display generation unit 76 determines whether the display end condition for the first reverse driving prevention content CTp1 is met. If a predetermined time has elapsed since the start of the display, if the reverse driving predictive operation is resolved, or if the driving scene of the host vehicle has transitioned from the first reverse driving scene Sn1 to the second reverse driving scene Sn2, the display end condition is met and the process proceeds to S206.

In S206, the scene determination unit 73 determines whether the current driving scene is the second reverse driving scene Sn2. If it is determined in S206 that the scene is not the second reverse driving scene Sn2, the process proceeds to S212. On the other hand, if it is determined in S206 that the scene is the second reverse driving scene Sn2, the process proceeds to S210. In S210, display control is performed to display the second reverse driving prevention content CTp2 (see FIG. 6, etc.), and the process proceeds to S211.

In S211, the scene determination unit 73 determines whether the display end condition of the second reverse driving prevention content CTp2 is satisfied. If the vehicle has returned to the correct driving lane Lnc, the display end condition of the second reverse driving prevention content CTp2 is satisfied. If it is determined in S211 that the display end condition is not satisfied, the process returns to S210. In this case, the display generation unit 76 continues to display the second reverse driving prevention content CTp2. On the other hand, if it is determined in S211 that the display end condition is satisfied, the process proceeds to S212. In S212, the display generation unit 76 ends the display of the reverse driving prevention content CTp that was started to be displayed in S203 or S210.

On the other hand, if it is determined in S201 that another vehicle is present around the vehicle, the scene determination unit 73 proceeds to S205 and determines whether or not it is an overtaking scene Snp. In S205, it is determined whether or not there is an overtaking target TP with a speed difference with respect to the vehicle. If it is determined in S205 that there is no overtaking target TP with a speed difference, it is determined that it is not an overtaking scene Snp, and the process proceeds to S206. On the other hand, if it is determined in S205 that there is an overtaking target TP with a speed difference, the process proceeds to S207.

In S207, the scene determination unit 73 determines whether the vehicle is protruding into the oncoming lane Lnw (hereinafter, the no-passing lane) where protruding is prohibited. If it is determined in S207 that the vehicle is protruding into the no-passing lane, it is deemed to be a second reverse driving scene Sn2, not an overtaking scene Snp, and the process proceeds to S210. On the other hand, if it is determined in S207 that the vehicle is protruding into the oncoming lane Lnw (hereinafter, the no-passing lane) where protruding is not prohibited, it is determined that the current driving scene is an overtaking scene Snp, and the process proceeds to S208. Similarly, if it is determined that the vehicle is not protruding from the driving lane Lnc, it is determined that the current driving scene is an overtaking scene Snp in which overtaking is performed within the driving lane Lnc, and the process proceeds to S208.

In S208, the scene determination unit 73 determines whether the time that has elapsed since the vehicle deviated into the overtaking lane has exceeded a predetermined time. The predetermined time may be a substantially constant time that has been determined in advance, or may be adjusted according to the speed difference between the vehicle and the overtaking target TP, so that the smaller the speed difference, the longer the time becomes. If it is determined in S208 that the time that has elapsed since the vehicle deviated into the overtaking lane has not exceeded the predetermined time, the process proceeds to S209. If overtaking is being performed within the driving lane Lnc, the process also proceeds to S209.

On the other hand, if it is determined in S208 that a predetermined time has elapsed since the vehicle ran into the overtaking lane, the determination result of the current driving scene is shifted from the overtaking scene Snp to the second wrong-way driving scene Sn2, and the process proceeds to S210. Note that the scene determination unit 73 may determine in S208 whether the distance traveled in the overtaking lane has exceeded a predetermined distance. In this case, if travel has continued for a predetermined distance after the vehicle ran into the overtaking lane, the determination result of the current driving scene is shifted from the overtaking scene Snp to the second wrong-way driving scene Sn2, and the process proceeds to S210.

In S209, the scene determination unit 73 determines whether or not there is a driving operation to return the vehicle to the driving position before the start of overtaking (hereinafter, a return operation) based on the operation information provided to the information acquisition unit 72 from the steering ECU 61 and the body ECU 63. The return operation includes a steering operation by the driver and a turn signal operation. If it is determined in S209 that there is no return operation, the process returns to S208. By repeating the processes of S208 and S209, the display of the second reverse running prevention content CTp2 is suspended until a predetermined time has elapsed. Then, if steering information to return to the original driving position is not detected within the predetermined time, the scene determination unit 73 determines that the current driving scene is the second reverse running scene Sn2. In this case, the display of the second reverse running prevention content CTp2 is started based on the transition of the process from S208 to S210. On the other hand, if it is determined in S209 that a return operation has been input before the predetermined time has elapsed, the current content display process is terminated.

The sixth embodiment described so far also has the same effect as the first embodiment, and detailed information related to reverse driving can be presented to the driver in an easy-to-understand manner by superimposing the reverse driving prevention content CTp. This makes it possible to improve convenience for the driver.

In addition, in the sixth embodiment, it is further determined whether or not the scene is an overtaking scene Snp in which vehicle A overtakes the overtaking target TP, and if it is determined that the scene is an overtaking scene Snp, the superimposed display of the reverse running prevention content CTp by the HUD 20 is suspended. Therefore, if the driver intentionally strays into the oncoming lane Lnw, the reverse running prevention content CTp is not used to warn the driver about reverse running. As a result, it is less likely that the reverse running prevention content CTp displayed erroneously during the overtaking scene Snp will cause annoyance to the driver. As a result, it is possible to further increase convenience for the driver.

In addition, in the sixth embodiment, if the vehicle strays into a no-overtaking lane, it is determined to be a second reverse driving scene Sn2, even if the vehicle is attempting to overtake. Therefore, if the driver misperceives the driving environment around the vehicle and performs an incorrect driving behavior, it becomes possible to appropriately issue a warning using reverse driving prevention content CTp.

Furthermore, in the sixth embodiment, detection information of other vehicles around the vehicle and detection information of the overtaking target TP are used to distinguish between the overtaking scene Snp and the second reverse driving scene Sn2. As a result of the above, the scene determination unit 73 can accurately distinguish whether the protrusion of the vehicle into the oncoming lane Lnw is an overtaking or reverse driving. As a result of the above, it becomes possible to appropriately display the reverse driving prevention content CTp, which can further improve convenience for the driver.

Seventh Embodiment
The seventh embodiment of the present disclosure shown in Figures 18 to 20 is yet another modified example of the first embodiment. The HCU 100 (see Figure 3) of the seventh embodiment displays reverse driving prevention content CTp (first reverse driving prevention content CTp1) together with the route guidance content CTnv in a guidance area GA that displays the route guidance content CTnv based on navigation information. Hereinafter, the information acquisition unit 72, the scene determination unit 73, and the display generation unit 76 of the seventh embodiment will be described in detail based on Figures 18 and 19 and with reference to Figures 1 to 3.

The information acquisition unit 72 identifies a guidance area GA for which route guidance is to be provided, based on navigation information including route information to a destination set in the navigation device 52. The guidance area GA includes intersections where right and left turns are required, branching points, merging points, etc. The information acquisition unit 72 refers to high-precision map data provided by the locator 40 and identifies no-entry areas Axe that exist in the guidance area GA.

The no-entry area Axe is an area where the vehicle is prohibited from entering, and includes areas where the vehicle will be traveling in the wrong direction and non-roadway areas where the vehicle A is prohibited from traveling at all. Specifically, in the route guidance scene SnN at an intersection, among the multiple lanes connected to the intersection, the lane whose prescribed traveling direction is opposite to the planned traveling direction of the vehicle (see dashed arrow in FIG. 18) is the no-entry area Axe (see dotted area in FIG. 18). Furthermore, in the route guidance scene SnN at an intersection, the sidewalk near the intersection is also recognized as the no-entry area Axe. Also, in the route guidance scene SnN at an interchange and a junction, the exit lane and the entrance lane whose prescribed traveling direction is opposite to the planned traveling direction of the vehicle are the no-entry area Axe.

The scene determination unit 73 determines that the scene is a route guidance scene SnN when the navigation device 52 requests the information acquisition unit 72 to perform guidance. In addition, the scene determination unit 73 determines that the scene is a first reverse driving scene Sn1 in which the vehicle A may be driving in the wrong direction when the information acquisition unit 72 has identified a no-entry area Axe related to the guidance area GA for which route guidance is to be performed based on the navigation information.

When the scene determination unit 73 determines that the scene is a route guidance scene SnN, the display generation unit 76 determines whether the guidance area GA is located within the angle of view VA. When the display generation unit 76 determines that the guidance area GA is located within the angle of view VA, the display generation unit 76 displays route guidance content CTnv that provides route guidance superimposed on the road surface within the guidance area GA. As an example, when providing route guidance for a right turn at an intersection (crossroads), the display generation unit 76 displays an image pointing to the right as route guidance content CTnv (see FIG. 19). The route guidance content CTnv is drawn so that it is viewed perpendicular to the road surface.

When the scene determination unit 73 determines that the scene is a route guidance scene SnN and a first reverse driving scene Sn1, the display generation unit 76 further determines whether or not the no-entry area Axe grasped by the information acquisition unit 72 is located within the angle of view VA. When the display generation unit 76 determines that the no-entry area Axe is located within the angle of view VA, it displays no-entry paint CTx superimposed on the foreground on which the route guidance content CTnv is superimposed. The no-entry paint CTx is superimposed content CTs equivalent to the reverse driving prevention content CTp and the first reverse driving prevention content CTp1. The no-entry paint CTx is drawn so as to be visually recognized as being aligned with the road surface.

When the vehicle approaches the guidance area GA, the display generation unit 76 starts superimposing the no entry paint CTx before starting the superimposing display of the route guidance content CTnv. In the guidance area GA where right-turn route guidance is performed, the no entry paint CTx is superimposed on the right side of the intersection as seen by the driver of the vehicle. The no entry paint CTx is displayed only on the turning side (right side) of the intersection, and is not displayed on the non-turning side (left side). The display generation unit 76 places the no entry paint CTx on the road surface that is the entrance to the opposite lane to prevent entry into the opposite lane, which would result in wrong-way driving. As a result, the no entry paint CTx is superimposed on the road surface closer to the driver than the superimposing position of the route guidance content CTnv.

After sequentially displaying the no entry painting CTx and the route guidance content CTnv, the display generation unit 76 hides the no entry painting CTx before the route guidance content CTnv when the vehicle approaches the guidance area GA. Specifically, the display generation unit 76 temporarily stops displaying the no entry painting CTx when the road surface that is the entrance to the opposite lane leaves the viewing angle VA.

Even after the display of the no entry painting CTx is interrupted, the display generation unit 76 continues the process of simulating the display layout of the no entry painting CTx in the virtual space using the virtual layout function described above. As a result, when the vehicle turns right in the intersection according to the route guidance content CTnv and the entrance road surface of the opposite lane is again within the field of view VA, the display generation unit 76 resumes the superimposed display of the no entry painting CTx.

The display generation unit 76 stops the superimposition of the no entry paint CTx in the guidance area GA where route guidance for a left turn is performed. When route guidance for a left turn is performed, the entrance road surface of the opposite lane is behind the superimposed position of the route guidance content CTnv as seen by the driver. Therefore, if the no entry paint CTx is superimposed on the entrance road surface of the opposite lane, the no entry paint CTx may overlap at least a part of the route guidance content CTnv. Therefore, the display generation unit 76 prioritizes the superimposition of the route guidance content CTnv over the no entry paint CTx in the guidance area GA where route guidance for a left turn is performed.

The seventh embodiment described so far also has the same effect as the first embodiment, and detailed information related to reverse driving can be presented to the driver in an easy-to-understand manner by the no entry painting CTx superimposed as reverse driving prevention content CTp. This makes it possible to improve convenience for the driver.

In addition, in the seventh embodiment, if a no-entry area Axe is present in the foreground on which the route guidance content CTnv is superimposed, the no-entry paint CTx is superimposed on the road surface leading to the no-entry area Axe. This prevents a driver who misinterprets the guidance provided by the route guidance content CTnv in the route guidance scene SnN from erroneously driving his or her vehicle into the no-entry area Axe. In this way, by displaying the no-entry paint CTx together with the route guidance content CTnv, the driver can easily recognize the correct route being guided by the route guidance content CTnv.

In the seventh embodiment, before the display of the route guidance content CTnv begins, the no entry painting CTx is superimposed on the road surface in front of the superimposition position of the route guidance content CTnv. This sequential display of the superimposed content makes it less likely that the driver will overlook the no entry painting CTx. In addition, because the no entry painting CTx is displayed first, the driver can determine the direction of travel of the vehicle according to the route guidance content CTnv after understanding the presence of the no entry area Axe. As a result of the above, the driver can more reliably steer the vehicle along the correct route.

Furthermore, in the seventh embodiment, the no entry painting CTx can be redisplayed after starting to turn at an intersection that is the guidance area GA. Therefore, if the driver makes an error in steering to the right and the vehicle attempts to move into the opposite lane, the no entry painting CTx is superimposed on the road surface in front of the driver. As a result, the no entry painting CTx can clearly warn the driver that he or she is moving into the opposite lane. As described above, redisplaying the no entry painting CTx can more reliably have the effect of stopping the vehicle from moving in the wrong direction.

The display generation unit 76 according to the seventh embodiment also displays the no entry painting CTx superimposed on the route guidance content CTnv in a route guidance scene SnN at a multi-junction (six-way intersection) as shown in FIG. 20. The display generation unit 76 can also draw the route guidance content CTnv so that it is visually recognized as being in line with the road surface, similar to the no entry painting CTx.

In more detail, when the planned driving route of the vehicle set in the navigation device 52 (see dashed arrow in FIG. 20) is directed to the road on the right side connected to the multi-way intersection, the display generation unit 76 superimposes the no entry paint CTx on the entrance road surface of the road on the right side. The no entry paint CTx may be superimposed only on the entrance road surface leading to the no entry area Axe of the road on the right side, or may be superimposed on the entire entrance road surface of the road on the right side. Even if the display generation unit 76 knows that the no entry area Axe is on the road on the right side, which is the planned driving route, it does not superimpose the no entry paint CTx on the road on the right side. The no entry paint CTx superimposed on the road on the right side not only has the effect of preventing the driver from entering the opposite lane of the road, but also has the effect of guiding the driver to the correct lane of the road on the right side.

In the seventh embodiment, the information acquisition unit 72 corresponds to the "area grasping unit."

Other Embodiments
Although several 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 not departing from the gist of the present disclosure.

In the first modification of the above embodiment, the first reverse driving scene Sn1 and the second reverse driving scene Sn2 are not distinguished. The scene determination unit 73 determines that a predetermined reverse driving scene SnX exists when there is a reverse driving precursor operation or when the vehicle is traveling in the oncoming lane Lnw. In the second modification of the above embodiment, only one of the first reverse driving scene Sn1 and the second reverse driving scene Sn2 is assumed in advance as the predetermined reverse driving scene SnX. In addition, in the first and second modifications, there may be only one type of reverse driving prevention content CTp.

In the third modification of the above embodiment, the display end condition of the first reverse driving prevention content CTp1 ( FIG. 9
For example, in the third modification, when a predetermined time has elapsed since the start of display of the first reverse-running prevention content CTp1 and the reverse-running predictive operation is eliminated, the display of the first reverse-running prevention content CTp1 is terminated.

In addition, in the fourth modification of the above embodiment, the display end condition of the second reverse-running prevention content CTp2 (see S106 in FIG. 9) is different from that of the above embodiment. For example, in the fourth modification, when a predetermined time has elapsed since the start of display of the second reverse-running prevention content CTp2, the display of the second reverse-running prevention content CTp2 is ended. Alternatively, when an oncoming vehicle TA is detected, the display of the second reverse-running prevention content CTp2 may be ended so as not to impede visibility of the oncoming vehicle TA.

In the fifth variation of the above embodiment, the process of the scene determination unit 73 that determines whether or not a partition object Ob is present is omitted. As a result, the display generation unit 76 displays the reverse driving prevention content CTp based on the determination that it is a specified reverse driving scene SnX, regardless of whether or not a partition object Ob is present. Also, in the sixth variation of the above embodiment, when the scene determination unit 73 detects the presence of a partition object Ob, the display generation unit 76 not only suspends the drawing of the drawing data of the reverse driving prevention content CTp in the video data, but also suspends the preparation of the drawing data of the reverse driving prevention content CTp.

In the seventh modified example of the sixth embodiment, the conditions for distinguishing between an overtaking scene and a wrong-way driving scene are different from those in the sixth embodiment. Specifically, in the seventh modified example, even if the vehicle is in a no-overtaking lane, if an overtaking target TP exists, the display of the wrong-way driving prevention content CTp is suspended. In the seventh modified example, when the vehicle is in a no-overtaking lane, the suspension time is set shorter than when the vehicle is in an overtaking allowed lane. That is, in an overtaking scene Snp in which the vehicle is in a no-overtaking lane, the predetermined time (see S208 in FIG. 17) for determining the elapsed time after the vehicle is overtaken is changed to be shorter than that in an overtaking scene Snp in which the vehicle is in an overtaking allowed lane.

In the above-described modified examples 8 to 10 of the seventh embodiment, the display control of the route guidance content CTnv and the reverse driving prevention content CTp (no entry paint CTx) differs from that of the seventh embodiment. Specifically, in modified example 8, the display generation unit 76 displays the route guidance content CTnv and the reverse driving prevention content CTp substantially simultaneously. That is, the display generation unit 76 starts the superimposed display of the route guidance content CTnv and the reverse driving prevention content CTp at the timing when the superimposed position of the route guidance content CTnv is within the angle of view VA.

The display generation unit 76 of the ninth modified example also displays the reverse driving prevention content CTp at an intersection where the vehicle makes a left turn. In the guidance area GA where the vehicle makes a right turn, the display generation unit 76 superimposes the reverse driving prevention content CTp on the closer side than the route guidance content CTnv. On the other hand, in the guidance area GA where the vehicle makes a left turn, the display generation unit 76 superimposes the reverse driving prevention content CTp on the farther side than the route guidance content CTnv.

As in the above-described variant example 9, if the angle of view VA of the HUD 20 is secured to be wide enough to avoid overlapping of the route guidance content CTnv and the reverse driving prevention content CTp, the reverse driving prevention content CTp may be displayed even in the guidance area GA where a left turn is to be made. Furthermore, in a form in which the angle of view VA of the HUD 20 is insufficient, in the guidance area GA where a left turn is to be made, icon-shaped non-overlapping content that warns of entering a no-entry area Axe may be displayed within the angle of view VA as the reverse driving prevention content CTp.

The display generation unit 76 of the tenth modification refers to steering information indicating the steering angle detected by the steering angle sensor 62, and when the steering angle is equal to or greater than a predetermined angle, determines that it is a first reverse driving scene Sn1 in which reverse driving is possible, and superimposes and displays reverse driving prevention content CTp. As a result, when the vehicle is proceeding toward the correct driving lane Lnc within the intersection, the re-display of the reverse driving prevention content CTp is stopped.

The superimposed position of the no-entry paint CTx displayed as the reverse driving prevention content CTp in the route guidance scene SnN may be changed as appropriate, for example, according to the angle of view VA of the HUD 20. As an example, if the angle of view VA of the HUD 20 is sufficiently wide, the no-entry paint CTx may be superimposed on a plurality of locations in the no-entry area Axe, without being limited to the entrance road surface of the no-entry area Axe. Furthermore, the form of the reverse driving prevention content CTp superimposed on the route guidance scene SnN is not limited to the no-entry paint CTx, and can be changed as appropriate. For example, a virtual barrier CTb (see FIG. 4), a virtual oncoming vehicle CTc (see FIG. 5), a virtual pedestrian, and a reverse arrow CTr (see FIG. 12), etc., may be displayed as the reverse driving prevention content CTp in the route guidance scene SnN.

In the above embodiment, a wrong-way driving scene in which the vehicle travels in the oncoming lane Lnw is illustrated, but the wrong-way driving prevention content CTp may be displayed in various wrong-way driving scenes. For example, a case in which the vehicle enters the wrong lane when turning right or left at an intersection, a case in which the vehicle mistakenly enters an interchange on the exit side connected to an expressway, and a case in which the vehicle enters an area that is not a roadway, such as a sidewalk or a railroad track, may be assumed in advance as a predetermined wrong-way driving scene SnX.

Furthermore, the display generation unit 76 may be able to change the form of the reverse driving prevention content CTp depending on the difference in the area during reverse driving. As an example, the scene determination unit 73 grasps the type of center line CL, specifically, the difference in color and shape of the center line CL. The display generation unit 76 changes the method of warning using the reverse driving prevention content CTp depending on whether the center line CL is a dashed white line, a solid white line, or a solid yellow (orange) line.

The form of the reverse driving prevention content CTp described in the above embodiment is one example. Specifically, static elements such as the content shape, display position, display color, and display brightness, as well as dynamic elements such as the presence or absence of blinking, the blinking cycle, the presence or absence of animation, and the operation of the animation, may be changed as appropriate. Furthermore, the static or dynamic elements of the reverse driving prevention content CTp may be changeable, for example, according to the driver's preferences.

The HCU in the above embodiment sequentially controls the projection shape and projection position of the virtual image light formed as the superimposed content CTs using eyepoint position information detected by the DSM so that the superimposed content is superimposed without deviation on the superimposition target as seen by the driver. However, the HCU in variant 11 of the above embodiment controls the projection shape and projection position of the virtual image light formed as the superimposed content using setting information of a preset reference eyepoint center without using the detection information of the DSM.

The specific configuration of the HUD 20 can be modified as appropriate. For example, in variant 12, the projector of the HUD is provided with an EL (Electro Luminescence) panel instead of an LCD panel and backlight. Furthermore, instead of an EL panel, a projector using a display such as a plasma display panel, a cathode ray tube, or an LED can be used for the HUD.

In the HUD of variant 13, a laser module (hereinafter, LSM) and a screen are provided instead of an LCD and a backlight. The LSM includes, for example, a laser light source and a MEMS (Micro Electro Mechanical Systems) scanner. The screen is, for example, a micromirror array or a microlens array. In such a HUD, a display image is drawn on the screen by scanning the laser light emitted from the LSM. The HUD projects the display image drawn on the screen onto the windshield using a magnifying optical element, displaying a virtual image in the air.

The HUD of variant 14 is equipped with a DLP (Digital Light Processing, registered trademark) projector. The DLP projector has a digital mirror device (hereinafter, DMD) equipped with many micromirrors, and a projection light source that projects light toward the DMD. The DLP projector draws a display image on a screen by controlling the DMD and the projection light source in coordination. The HUD of variant 15 employs a projector that uses LCOS (Liquid Crystal On Silicon). The HUD of variant 16 employs a holographic optical element as one of the optical systems that displays a virtual image in the air.

In variant 17 of the above embodiment, the HCU 100 is provided with a camera image acquisition unit that acquires imaging data from the front camera 31, the imaging data being an image of the view in front of the vehicle. The display generation unit 76 generates video data in which an original image of the reverse driving prevention content CTp is superimposed on a real image of the foreground based on the imaging data. Based on this video data, the HUD 20 projects a display in which the reverse driving prevention content CTp is superimposed on the real image as a virtual image in the foreground. As in variant 17 above, when the angle of view VA of the HUD 20 is insufficient, in scenes where the AR content falls outside the angle of view VA, a virtual image display in which an original image of the content used for the AR display is superimposed on the real image may be implemented.

In variant 18 of the above embodiment, the HCU and HUD are configured as an integrated unit. That is, the control circuit of the HUD in variant 18 is equipped with the processing functions of the HCU. In this variant, the HUD corresponds to the "display control device." Furthermore, the processing functions of the HCU may be equipped in the meter ECU, navigation ECU, display audio ECU, etc. In this variant, the meter device, navigation device, and display audio device each correspond to the "display control device."

In the above embodiment, each function provided by the HCU can be provided by software and hardware that executes it, 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.

The form of the storage medium (non-transitory tangible storage medium) that stores the program capable of implementing the above-mentioned display control method may also be changed as appropriate. For example, the storage medium is not limited to being 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 the control circuit of the HCU. Furthermore, the storage medium may be an optical disk or hard disk drive that is the source from which the program is copied to the HCU.

Vehicles equipped with an HMI system are not limited to general private passenger cars, but may also be rental cars, manned taxi cars, ride-sharing cars, freight cars, buses, etc.

The vehicle equipped with the HMI system may be a right-hand drive vehicle or a left-hand drive vehicle. 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 content display for the purpose of preventing wrong-way driving according to the present disclosure is optimized as appropriate according to the road traffic laws of each country and region, as well as the position of the vehicle's steering wheel, etc.

The control unit and the method described in the present disclosure may be realized by a dedicated computer comprising a processor programmed to execute one or more functions embodied in a computer program. Alternatively, the device and the method described in the present disclosure may be realized by a dedicated hardware logic circuit. Alternatively, the device and the method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor that executes a computer program and one or more hardware logic circuits. Furthermore, the computer program may be stored in a computer-readable non-transient tangible recording medium as instructions executed by the computer.

A vehicle, Axe no entry area, CL center line, CTnv route guidance content, CTp wrong-way driving prevention content, CTf forward arrow (forward content), CTr reverse arrow (reverse content), Lnc driving lane, Lnw oncoming lane, Ob partition mark (obstacle), TP overtaking target, Snp overtaking scene, SnN route guidance scene, SnX specified wrong-way driving scene, Sn1 first wrong-way driving scene, Sn2 second wrong-way driving scene, 11 processing unit, 20 HUD (head-up display), 64 direction indicator switch (direction indicator), 72 information acquisition unit (area grasping unit), 73 scene determination unit, 76 display generation unit (display control unit), 100 HCU (display control unit)

Claims (18)

A display control device for use in a vehicle (A) and for controlling a display by a head-up display (20),
a scene determination unit (73) for determining whether or not a predetermined wrong-way driving scene (SnX) assumed in advance in relation to the wrong-way driving of the vehicle occurs;
a display control unit (76) that causes the head-up display to superimpose on a road surface in the foreground a wrong-way driving prevention content (CTp) that guides the vehicle to drive in a correct driving lane (Lnc) when the predetermined wrong - way driving scene occurs ;
The display control unit is
start displaying the reverse running prevention content based on an ON operation of a direction indicator (64) of the vehicle;
A display control device that changes the reverse driving prevention content displayed based on the on operation to an emphasized state based on a steering operation that brings the vehicle closer to a center line (CL) that is the boundary between the driving lane and the oncoming lane ( Lnw). The scene determination unit further determines the presence or absence of an obstacle (Ob) existing between the driving lane and the oncoming lane (Lnw),
The display control device according to claim 1 , wherein the display control unit suspends the superimposed display of the reverse running prevention content on the head-up display when the obstacle is present. A display control device for use in a vehicle (A) and for controlling a display by a head-up display (20),
a scene determination unit (73) for determining whether or not a predetermined wrong-way driving scene (SnX) assumed in advance in relation to the wrong-way driving of the vehicle occurs;
a display control unit (76) that causes the head-up display to superimpose on a road surface in the foreground a wrong-way driving prevention content (CTp) that guides the vehicle to drive in a correct driving lane (Lnc) when the predetermined wrong - way driving scene occurs ;
The scene determination unit further determines the presence or absence of an obstacle (Ob) existing between the driving lane and the oncoming lane (Lnw),
The display control unit is a display control device that suspends the superimposed display of the reverse running prevention content on the head-up display when the obstacle is present . The scene determination unit continues to determine whether or not the scene is the predetermined reverse driving scene even if the obstacle is present,
The display control device according to claim 2 or 3, wherein the display control unit continues preparing drawing data for the reverse driving prevention content during a period in which the scene determination unit determines that the scene is the specified reverse driving scene, even if the obstacle is present. The display control device according to any one of claims 1 to 4, wherein the scene determination unit includes, in determining whether or not a specific reverse-driving scene is present, a first scene determination for determining whether or not a specific reverse-driving scene is present (Sn1) in which the vehicle is likely to drive in the wrong direction, and a second scene determination for determining whether or not a specific reverse-driving scene is present ( Sn2) in which the vehicle is actually driving in the wrong direction. The display control device according to claim 5 , wherein the scene determination unit determines whether or not the scene is the first wrong-way driving scene based on operation information related to an operation of a driver who drives the vehicle. The display control device according to claim 6, wherein the display control unit changes a content of the reverse-driving prevention content in accordance with a content of an operation by the driver indicated by the operation information when the scene determination unit determines that the scene is the first reverse-driving scene. 8. The display control device according to claim 6 or 7, wherein, when the scene determination unit determines that the scene is the first reverse-driving scene, the display control unit continues to display the reverse-driving prevention content until a predetermined time has elapsed since the start of display of the reverse-driving prevention content, or until the driver's operation that caused the determination that the scene is the first reverse-driving scene is resolved. The display control device according to any one of claims 5 to 8, wherein, after displaying the reverse-driving prevention content based on a determination that the scene is the first reverse-driving scene, when the vehicle driving scene transitions to the second reverse-driving scene, the display control unit displays the reverse-driving prevention content different from the reverse-driving prevention content displayed in the first reverse -driving scene. The display control device according to any one of claims 5 to 8, wherein, when the vehicle driving scene transitions to the second reverse-driving scene after displaying the reverse-driving prevention content based on a determination that the scene is the first reverse-driving scene, the display control unit continues displaying the reverse-driving prevention content that was started in the first reverse-driving scene, while emphasizing an aspect of the reverse-driving prevention content more than the first reverse - driving scene. The display control device according to claim 9 or 10 , wherein the display control unit superimposes at least a part of the reverse-driving prevention content to be displayed in the second reverse-driving scene on a road surface of the driving lane in which the vehicle is to travel. The display control device according to any one of claims 5 to 11, wherein the display control unit, when the scene determination unit determines that the scene is the second reverse-driving scene, continues to display the reverse-driving prevention content until the vehicle returns to the driving lane. The scene determination unit further determines whether or not the scene is an overtaking scene (Snp) in which the vehicle overtakes an overtaking target (TP),
The display control device according to any one of claims 1 to 12 , wherein the display control unit suspends superimposed display of the reverse driving prevention content on the head-up display when the scene determination unit determines that the scene is an overtaking scene. The vehicle further includes an area ascertaining unit (72) for ascertaining a no-entry area (Axe) into which the vehicle is prohibited from entering,
The display control device according to any one of claims 1 to 13, wherein when the no-entry area is present in the foreground where route guidance content ( CTnv ) that provides route guidance is superimposed, the display control unit superimposes the reverse driving prevention content on a road surface leading to the no-entry area. The display control device according to claim 14 , wherein the display control unit causes the reverse running prevention content to be superimposed and displayed on a road surface in front of a superimposition position of the route guidance content before display of the route guidance content is started. The display control device according to any one of claims 1 to 15, wherein when the scene determination unit determines that the scene is the specified reverse driving scene, the display control unit displays reverse direction content (CTr) indicating the driving direction of the oncoming lane ( Lnw ) as the reverse driving prevention content, and then displays forward direction content (CTf) indicating the driving direction of the driving lane. A display control program for use in a vehicle (A) and for controlling a display by a head-up display (20), comprising:
At least one processing section (11)
It is determined whether or not a predetermined wrong-way driving scene (SnX) that is assumed in advance in relation to the wrong-way driving of the vehicle occurs (S101, S104, S202, S206).
When the predetermined wrong-way driving scene occurs, a wrong-way driving prevention content (CTp) for guiding the vehicle to drive in the correct driving lane (Lnc) is displayed superimposed on the road surface in the foreground by the head-up display (S102, S105, S203, S210).
performing a process including
In the process of superimposing and displaying the reverse running prevention content,
start displaying the reverse running prevention content based on an ON operation of a direction indicator (64) of the vehicle;
A display control program that changes the reverse driving prevention content displayed based on the on operation to an emphasized state based on a steering operation that brings the vehicle closer to a center line (CL) that is the boundary between the driving lane and the oncoming lane (Lnw) . A display control program for use in a vehicle (A) and for controlling a display by a head-up display (20), comprising:
At least one processing section (11)
It is determined whether or not a predetermined wrong-way driving scene (SnX) that is assumed in advance in relation to the wrong-way driving of the vehicle occurs (S101, S104, S202, S206).
When the predetermined wrong-way driving scene occurs, a wrong-way driving prevention content (CTp) for guiding the vehicle to drive in the correct driving lane (Lnc) is superimposed on the road surface in the foreground by the head-up display ( S102, S105, S203, S210).
Further, the presence or absence of an obstacle (Ob) existing between the driving lane and the oncoming lane (Lnw) is determined;
interrupting the superimposed display of the reverse running prevention content on the head-up display when the obstacle is present;
A display control program that causes a process including the above to be performed.

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