DISPLAY CONTROL DEVICE FOR A VEHICLE

A display control device for a vehicle, includes an image forming section configured to form an AR image having a shape that conforms to a dividing line of a lane in which a vehicle travels, an object recognition section configured to recognize object positioned in the lane, and a processor configured to control the image forming section so as to form the AR image. In a case in which it has been determined, based on a distance between the vehicle and the object, that there is a possibility that the AR image will overlap with the object, the processor reduces a visibility of a specific portion of the AR image, which is a portion that has a possibility of overlapping with the object, relative to a case in which it has not been determined that there is a possibility that the AR image will overlap with the object.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2022-190590 filed on Nov. 29, 2022, the disclosure of which is incorporated by reference herein.

BACKGROUND

Technical Field

The present disclosure relates to a display control device for a vehicle.

Related Art

Japanese Patent Application Laid-Open (JP-A) No. 2020-128172 discloses a vehicle including a head-up display capable of forming an AR image (virtual image) in a virtual display region. This AR image has a shape that conforms to a dividing line of a road, and is an image that an occupant recognizes as overlapping with the dividing line. Moreover, in a case in which the AR image is formed so as to overlap with an obstacle positioned on the dividing line, display of a portion of the AR image that overlaps with the object is limited.

In a case in which a camera of the vehicle is unable to accurately detect the shape of the dividing line, the AR image may be formed so as to overlap with an obstacle that is at a position that is separated from the dividing line. Thus, the invention of Japanese Patent Application Laid-Open (JP-A) No. 2020-128172 has room for improvement with regard to making it less likely for the occupant of the vehicle to feel annoyance in such a case.

In consideration of the above facts, an object of the present disclosure is to provide a display control device for a vehicle that is less likely to make an occupant of a vehicle feel annoyance in a case in which an AR image having a shape that conforms to a dividing line of a lane is formed so as to overlap with an object that is at a position that is separated from the dividing line.

SUMMARY

A display control device for a vehicle according to a first aspect of the present disclosure includes: an image forming section configured to form an AR image having a shape that conforms to a dividing line of a lane in which a vehicle travels; an object recognition section configured to recognize an object positioned in the lane; and a processor configured to control the image forming section so as to form the AR image, wherein, in a case in which it has been determined, based on a distance between the vehicle and the object, that there is a possibility that the AR image will overlap with the object, the processor reduces a visibility of a specific portion of the AR image, which is a portion that has a possibility of overlapping with the object, relative to a case in which it has not been determined that there is a possibility that the AR image will overlap with the object.

In the display control device for a vehicle according to the first aspect, in a case in which it has been determined, based on the distance between the vehicle and the object positioned in the lane, that there is a possibility that the AR image having a shape that conforms to the dividing line will overlap with the object, the visibility of the specific portion of the AR image, which is a portion that has a possibility of overlapping with the object, is reduced compared to a case in which it has not been determined that there is a possibility that the AR image will overlap with the object. Consequently, even in a case in which, for example, the AR image is formed such that the specific portion overlaps with an object that is at a position that is separated from the dividing line, it is unlikely that an occupant who visually recognizes the object and the specific portion will feel annoyance.

A display control device for a vehicle according to a second aspect of the present disclosure is the display control device for a vehicle according to the first aspect, wherein the processor is configured to reduce a luminance of the specific portion of the AR image relative to a luminance of portions of the AR image other than the specific portion.

In the display control device for a vehicle according to the second aspect, the luminance of the specific portion of the AR image is reduced compared to the luminance of portions of the AR image other than the specific portion. Consequently, even if the specific portion of the AR image formed by the display control device for a vehicle according to the second aspect overlaps with an object that is at a position that is separated from the dividing line, it is unlikely that an occupant who visually recognizes the object and the specific portion will feel annoyance.

A display control device for a vehicle according to a third aspect of the present disclosure is the display control device for a vehicle according to the first aspect, wherein the processor is configured to determine the specific portion based on a specific distance, which is the distance between the vehicle and the object.

In the display control device for a vehicle according to the third aspect, the specific portion is determined based on the specific distance, which is the distance between the vehicle and the object. Consequently, there is a possibility that the specific portion determined by the display control device for a vehicle according to the third aspect will overlap with the object.

A display control device for a vehicle according to a fourth aspect of the present disclosure is the display control device for a vehicle according to the third aspect, wherein the processor is configured to determine the specific portion such that the specific portion includes a portion positioned further forward than a portion that is positioned the specific distance forward from the vehicle in the AR image.

In the display control device for a vehicle according to the fourth aspect, the specific portion is determined such that the specific portion includes the portion positioned further forward than the portion that is positioned the specific distance forward from the vehicle in the AR image. Consequently, the display control device for a vehicle according to the fourth aspect can include a portion that has a high probability of overlapping with the object in the specific portion with high accuracy.

As described above, the display control device for a vehicle according to the present disclosure has an excellent advantageous effect in that an occupant of the vehicle is unlikely to feel annoyance in a case in which the AR image having a shape that conforms to the dividing line of the lane is formed so as to overlap with an object that is at a position that is separated from the dividing line.

DETAILED DESCRIPTION

An exemplary embodiment of a display control device for a vehicle10(hereafter referred to as a “control device10”) according to the present disclosure will be explained below with reference to the drawings. An arrow FR illustrated in the drawings as appropriate indicates a front side in a vehicle front-rear direction, an arrow LH indicates a left side in a vehicle left-right direction, and an arrow UP indicates an upper side in a vehicle up-down direction.

As illustrated inFIG.1, a vehicle12installed with the control device10of the present exemplary embodiment includes a front windshield14and an instrument panel16. The instrument panel16is provided with a driving assistance operation device23. A sensor unit (object recognition section)20is provided at an upper portion of a vehicle inside surface of the front windshield14. The sensor unit20includes a camera21and a millimeter-wave sensor22. The camera21is capable of photographing a subject positioned ahead of the vehicle from the camera21itself. The millimeter-wave sensor22transmits scanning waves directed forward and receives reflected waves.

The driving assistance operation device23is a device for causing the vehicle12to execute driving assistance control, which will be described later. When the driving assistance operation device23is in an ON state, the vehicle12is capable of executing driving assistance control. When the driving assistance operation device23is in an OFF state, the vehicle12is unable to execute driving assistance control.

As illustrated inFIG.2, the vehicle12includes an AR-HUD device (head-up display device) (image forming section)24(hereinafter referred to as a “HUD”) including a projection device.

As illustrated inFIG.2, the vehicle12includes an electronic control unit (ECU)26as a hardware configuration.

The ECU26is configured to include a central processing unit (CPU) (processor) (computer)26A, a read only memory (ROM) (non-transitory recording medium) (recording medium)26B, a random access memory (RAM)26C, a storage (non-transitory recording medium) (recording medium)26D, a communication I/F26E, and an input/output I/F26F. The CPU26A, the ROM26B, the RAM26C, the storage26D, the communication I/F26E, and the input/output I/F26F are connected so as to be capable of communicating with each other via an internal bus26Z.

The CPU26A is a central arithmetic processing unit, and the CPU26A executes various programs and controls various sections. The CPU26A reads a program from the ROM26B or the storage26D, and executes the program using the RAM26C as a workspace. The CPU26A carries out control of the respective configurations and various kinds of arithmetic processing according to programs recorded in the ROM26B or the storage26D.

The ROM26B stores various programs and various data. The RAM26C serves as a workspace to temporarily store programs and data. The storage26D is configured by a storage device such as a hard disk drive (HDD), a solid state drive (SSD) or the like, and stores various programs and various data.

The communication I/F26E is an interface for connecting to a different ECU (not illustrated in the drawings) from the ECU26via an external bus (not illustrated in the drawings). For example, a communication standard based on the CAN protocol is used for this interface.

The input/output I/F26F is an interface for communicating with various devices. These devices include the sensor unit20, the driving assistance operation device23, the HUD24, a sensor group (which will be described later), and an actuator group (which will be described later).

FIG.3is a block diagram illustrating an example of a functional configuration of the ECU26. The ECU26includes a driving assistance control section261and a HUD control section262as functional configuration. The driving assistance control section261and the HUD control section262are implemented by the CPU26A reading and executing a program stored in the ROM26B.

When the driving assistance operation device23is in the ON state, the driving assistance control section261uses the sensor group and the actuator group (not illustrated in the drawings) provided at the vehicle12to cause the vehicle12to execute driving assistance control at driving levels1to5determined by the Society of Automotive Engineers (SAE) (American Society of Automotive Engineers). Moreover, when the driving assistance operation device23is in the ON state, a driver (occupant) D (refer toFIG.1) of the vehicle12can select the driving level and the driving assistance control to be executed, by operating the driving assistance operation device23. The driving assistance control according to the present exemplary embodiment includes, for example, adaptive cruise control (ACC), lane tracing assistance (LTA, lane maintenance assistance control), and lane departure alert control (LDA). The sensor group provided at the vehicle12includes a sensor unit20. The actuator group provided at the vehicle12includes an electric actuators of a brake device and an electric steering device, an electric actuator for driving an internal combustion engine, which is a drive source, and an electric motor, which is a drive source.

The HUD control section262controls the HUD24. The ROM26B or the storage26D of the ECU26stores projection object data including various characters, icons (graphics) and the like. The projection device of the HUD24controlled by the HUD control section262reads the projection object data from the ROM26B or the storage26D to project various types of AR images. These AR images include dividing line display images Imx1and Imx2, which will be described later. Namely, the HUD24is an augmented reality head-up display (AR-HUD). The projected AR images are reflected forward by a reflecting section (not illustrated in the drawings) provided at the vehicle12. Moreover, the AR images reflected forward by the reflecting section are formed as virtual images in a virtual display region HA (refer toFIG.1) positioned in front of the front windshield14.

Moreover, when the vehicle12is executing LTA or LDA, the HUD control section262recognizes shapes of dividing lines provided at left and right side edges of an immediately preceding region of the road (lane) on which the vehicle12is traveling, based on image data acquired by the camera21. The immediately preceding region is a region that is a part of the lane in which the vehicle12is traveling and that is positioned immediately ahead of the vehicle12. A front-rear length of this immediately preceding region can be set arbitrarily, and can be set to, for example, 50 m. Moreover, based on planar shapes of the dividing lines that have been recognized, the HUD control section262reads, from among the projection object data, projection object data representing dividing line display images having a shape that conforms to the dividing lines that have been recognized. It should be noted that the “shape that conforms to the dividing lines” includes a shape that is the same as a portion of the dividing lines, and a shape that is similar to a portion of the dividing lines. As illustrated inFIG.4andFIG.5, the type of projected dividing line display images differs depending on a planar shape of the immediately preceding region of the lane in which the vehicle12is traveling.

For example, a case in which the vehicle12is traveling on a road (lane)30illustrated inFIG.4, and a planar shape of an immediately preceding region FA1is a substantially linear shape, is presumed. A planar shape of dividing line display images Imx1in this case is a substantially linear shape. As illustrated inFIG.4, the HUD control section262forms the dividing line display images Imx1so that a left side dividing line display image Imx1is adjacent to a right side edge of a left side dividing line30L that has been recognized (specified) by the HUD control section262, and a right side dividing line display image Imx1is adjacent to the a left side edge of a right side dividing line30R that has been recognized (specified) by the HUD control section262. Hereinafter, as illustrated by the solid lines inFIG.4, a formation position of the dividing line display images Imx1in a case in which the left side dividing line display image Imx1is adjacent to the right side edge of the actual left side dividing line30L and the right side dividing line display image Imx1is adjacent to the left side edge of the actual right side dividing line30R is referred to as a design position. However, the HUD control section262recognizes the dividing lines30L and30R based on only the image data acquired by the camera21. In other words, the HUD control section262cannot use detection data from the millimeter-wave sensor22when recognizing the dividing lines30L and30R. Consequently, the HUD control section262may be unable to accurately recognize the positions and shapes of the dividing lines30L and30R in the immediately preceding region FA1. In this case, for example, as illustrated by the virtual lines inFIG.4, there is a possibility that the left and right dividing line display images Imx1may be formed so that the driver recognizes that the right side dividing line display image Imx1is separated to the left side from the actual right side dividing line30R and the left side dividing line display image Imx1(not illustrated in the drawing) is separated to the left side from the actual left side dividing line30L. Consequently, there is a possibility that the driver may recognize that a portion of the right side dividing line display image Imx1is overlapped with a preceding vehicle (object)50that is traveling on the road30and that is positioned ahead of the vehicle12.

Accordingly, when it has been determined that the preceding vehicle50is traveling in the immediately preceding region based on detection data from the sensor unit20, the HUD control section262carries out luminance adjustment processing, which is an example of visibility reduction processing, on the dividing line display images Imx1as required.

Namely, based on the detection data from the sensor unit20, the HUD control section262calculates an inter-vehicle distance (specific distance) (distance) DS1between the vehicle12and the preceding vehicle50. Moreover, the HUD control section262determines whether or not an orthogonal line PL1that is orthogonal to an extension direction ED1of the road30and that passes through a rear end of the preceding vehicle50, and the left and right dividing line display images Imx1in the case of being formed at the design position, intersect with each other. In other words, the HUD control section262determines whether or not there is a possibility that a portion of the dividing line display images Imx1will overlap with the preceding vehicle50traveling on the road30. Hereinafter, a determination that the orthogonal line PL1(PL2) and the dividing line display images Imx1(Imx2) intersect with each other is referred to as an “intersection determination”. In a case in which the intersection determination has been made, the HUD control section262calculates a position of an intersection CP1between the orthogonal line PL1and the dividing line display images Imx1. The intersection CP1is a portion positioned substantially at the inter-vehicle distance DS1ahead of the vehicle12. Moreover, the HUD control section262calculates a position RP1on the dividing line display images Imx1that is separated toward the rear from the intersection CP1by a predetermined distance. This predetermined distance can be set arbitrarily and is, for example, 2 m. Moreover, the HUD control section262reduces a luminance of a specific portion SP1, which is a portion positioned ahead of the position RP1of the left and right dividing line display images Imx1, relative to a case in which no intersection determination has been made. Accordingly, the luminance of the specific portion SP1becomes lower than a luminance of portions of the dividing line display images Imx1other than the specific portion SP1.

In a case in which the luminance of the specific portion SP1of the left and right dividing line display images Imx1is reduced in this manner, as illustrated by the virtual lines inFIG.4, there are cases in which the right side dividing line display image Imx1is formed such that the driver recognizes that the specific portion SP1is overlapped with the preceding vehicle50. However, compared to a case in which the luminance adjustment processing is not carried out, the driver who has visually recognized the specific portion SP1and the preceding vehicle50is less likely to feel annoyance.

Further, a case in which the vehicle12is traveling on a road (lane)40illustrated inFIG.5, and a planar shape of an immediately preceding region FA2is substantially a circular arc shape, is presumed. The planar shape of the dividing line display images Imx2in this case is substantially a circular arc shape. In this case, based on the detection data from the sensor unit20, the HUD control section262calculates an inter-vehicle distance (specific distance) (distance) DS2between the vehicle12and the preceding vehicle50. Moreover, the HUD control section262determines whether or not an orthogonal line PL2that is orthogonal to an extension direction ED2of the immediately preceding region FA2of the road40and that passes through the rear end of the preceding vehicle50, and the left and right dividing line display images Imx2in the case of being formed at the design position, intersect with each other. In other words, the HUD control section262determines whether or not there is a possibility that a portion of the dividing line display images Imx2will overlap with the preceding vehicle50traveling on the road40. In a case in which an intersection determination has been made, the HUD control section262calculates a position of an intersection CP2between the orthogonal line PL2and the dividing line display images Imx2. The intersection CP2is a portion positioned substantially the inter-vehicle distance DS2ahead of the vehicle12. Moreover, the HUD control section262calculates a position RP2on the dividing line display images Imx2that is separated toward the rear from the intersection CP2by the aforementioned predetermined distance. Moreover, the HUD control section262reduces a luminance of a specific portion SP2, which is a portion positioned ahead of the position RP2of the left and right dividing line display images Imx2, compared to a case in which no intersection determination has been made. Accordingly, the luminance of the specific portion SP2becomes lower than a luminance of portions of the dividing line display images Imx2other than the specific portion SP2.

In a case in which the luminance of the specific portion SP2of the left and right dividing line display images Imx2is reduced in this manner, as illustrated by the virtual lines inFIG.5, there are cases in which the right side dividing line display image Imx2is formed such that the driver recognizes that the specific portion SP2is overlapped with the preceding vehicle50. However, compared to a case in which the luminance adjustment processing is not carried out, the driver who has visually recognized the specific portion SP2and the preceding vehicle50is less likely to feel annoyance.

Among the configurations described above, the sensor unit20, the driving assistance operation device23, the HUD24, the ECU26, the sensor group, and the actuator group are constituent elements of the control device10.

Next, processing executed by the CPU26A of the ECU26will be explained. The CPU26A repeatedly executes the processing of the flowchart illustrated inFIG.6each time a predetermined amount of time has elapsed.

At step S10(hereinafter, the word “step” will be omitted), the CPU26A determines whether or not the vehicle12is executing LTA or LDA.

In a case in which the determination is YES at S10, the CPU26A proceeds to S11and causes the HUD24to form the dividing line display images. For example, in a case in which the vehicle12is traveling on the road30, the CPU26A causes the HUD24to form the dividing line display images Imx1.

Next, the CPU26A proceeds to S12and determines whether or not a preceding vehicle is present in the immediately preceding region. For example, in a case in which the preceding vehicle50is traveling in the immediately preceding region FA1inFIG.4, the CPU26A makes a determination of Yes at S12.

In a case in which the determination is YES at S12, the CPU26A proceeds to S13and determines whether or not there is a possibility that the dividing line display images Imx1or Imx2will overlap with the preceding vehicle50. In other words, the CPU26A determines whether or not the dividing line display images Imx1or Imx2, and the orthogonal line PL1or PL2, intersect with each other.

In a case in which the determination is YES at S13, the CPU26A proceeds to S14and determines the specific portion SP1or SP2of the dividing line display images Imx1or Imx2.

In a case in which the processing of S14has been completed, the CPU26A proceeds to S15and carries out luminance adjustment processing for the determined specific portion SP1or SP2.

When a determination of No has been made at S10,12, or13, or when the processing of S15has been completed, the CPU26A temporarily ends the processing of the flowchart ofFIG.6.

As described above, the control device10of the present exemplary embodiment determines whether or not there is a possibility that the dividing line display images Imx1or Imx2having shapes that conform to the dividing lines30L and30R, or40L and40R, will overlap with the preceding vehicle50, based on the inter-vehicle distance DS1or DS2between the preceding vehicle50traveling in the immediately preceding region FA1or FA2of the road30or40, and the vehicle12. Moreover, in a case in which an intersection determination has been made, the control device10reduces the luminance of the specific portion SP1or SP2, which is the portion at which the dividing line display images Imx1or Imx2have a possibility of overlapping with the preceding vehicle50, relative to a case in which no intersection determination has been made. In other words, the control device10reduces the visibility of the specific portion SP1or SP2. Consequently, even in a case in which the driver D recognizes that the specific portion SP1or SP2is overlapped with the preceding vehicle50, the driver D is less likely to feel annoyance.

Moreover, the control device10determines the specific portion SP1or SP2based on the inter-vehicle distance DS1or DS2, which is the distance between the vehicle12and the preceding vehicle50. More specifically, the control device10determines the range of the specific portion SP1or SP2such that the specific portion SP1or SP2includes a portion positioned ahead of the intersection CP1or CP2, which is a portion of the dividing line display images Imx1or Imx2that is substantially separated from the vehicle12toward the front by the inter-vehicle distance DS1or DS2. Consequently, there is a high probability that the specific portion SP1or SP2determined by the control device10will overlap with the preceding vehicle50in a case in which the dividing line display images Imx1or Imx2are formed so as to be separated from the dividing lines30L and30R, or40L and40R. Namely, the control device10is capable of including a portion that has a high probability of overlapping with the preceding vehicle50in a case in which the dividing line display images Imx1or Imx2are formed so as to be separated from the dividing lines30L and30R, or40L and40R, in the specific portion SP1or SP2with high accuracy.

Moreover, the specific portion SP1or SP2determined by the control device10also includes a portion that is a part of the dividing line display images Imx1or Imx2and that is positioned rearward of the intersection CP1or CP2. In a case in which recognition accuracy of the dividing lines30L and30R by the HUD control section262is low, there is a possibility that the portion of the dividing line display images Imx1or Imx2that is positioned rearward of the intersection CP1or CP2will overlap with the preceding vehicle50. Consequently, compared with a case in which the specific portion SP1or SP2does not include the portion positioned rearward of the intersection CP1or CP2, the dividing line display images Imx1and Imx2of the present exemplary embodiment are less likely to make the driver D feel annoyance in a case in which they overlap with the preceding vehicle50.

Although explanation has been given above regarding the control device10according to the exemplary embodiment, the design of the control device10may be modified as appropriate within a range that does not depart from the spirit of the present disclosure.

For example, the visibility reduction processing that reduces the visibility of the specific portions SP1and SP2may be different processing from the luminance adjustment processing. For example, the visibility reduction processing may be processing that makes line widths of the specific portions SP1and SP2narrower than in a case in which no intersection determination has been made. Alternatively, the visibility reduction processing may be processing in which the specific portions SP1and SP2are represented by dotted lines.

In a case in which an intersection determination has been made, the visibility of the entire dividing line display images Imx1or Imx2may be reduced compared with a case in which no intersection determination has been made. For example, the luminance of the entire dividing line display images Imx1or Imx2may be reduced.

For example, a configuration may be provided in which images (not illustrated in the drawings) representing a road (lane) on which the vehicle12is traveling and right and left dividing lines are displayed on a display17(refer toFIG.1) provided at the instrument panel16. In this case, dividing line display images (not illustrated in the drawings) corresponding to the left and right dividing lines are displayed on the display17. In a case in which an intersection determination has been made in this modified example, visibility reduction processing may be performed on a specific portion of the dividing line display images or on the entire dividing line display images.

Moreover, the visibility reduction processing may be performed on the specific portion of the dividing line display images when it has been determined that there is a possibility that a portion of the dividing line display images will overlap with a different object from the preceding vehicle50that is positioned in the lane in which the vehicle12is traveling. Such objects include, for example, pedestrians and motorcycles.

Further, a configuration may be provided in which the portion positioned rearward of the intersection CP1or CP2is not included in the specific portion SP1or SP2.