Display control device and display control program

Abstract

To provide a display control device, etc. that are able to prevent erroneous correction caused by a road gradient even in a form in which a detection value of a gyro sensor is used for correcting a display position of a virtual image.SOLUTION: An HMI-ECU is a display control device, is used in a vehicle, and controls display of a virtual image superimposed on a foreground visible from a driver. The HMI-ECU acquires a detection value of a gyro sensor that detects a behavior change in a pitch direction, which occurs in the vehicle; and, based on the detection value, corrects a deviation of a display position of the virtual image with respect to the foreground, which is caused by the behavior change. Further, the HMI-ECU acquires gradient information related to a gradient of a road on which the vehicle travels; and, in accordance with the gradient information, changes contents of correction for correcting the deviation of the display position.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The disclosure in this specification relates to a display control technique for controlling the display of a virtual image. [Background technology]

[0002] Patent Document 1 discloses an information display system that uses a head-up display device to display an image superimposed on the actual scenery visually recognized by the driver. In this information display system, the amount of change in attitude in the pitch direction caused by acceleration or deceleration of the vehicle is estimated mainly based on the detection value of a height sensor, and the projection position of the image is corrected according to the estimated current vehicle attitude. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-20625 Summary of the Invention [Problem to be solved by the invention]

[0004] To detect a change in the vehicle's attitude in the pitch direction, a gyro sensor can be used in addition to a height sensor as in Patent Document 1. However, the detection value of the gyro sensor may include not only information on detected attitude changes due to acceleration / deceleration, but also information on detected attitude changes due to road gradient. As a result, if the detection value of the gyro sensor is used as is, there is a risk that an erroneous correction due to the road gradient will be performed.

[0005] The present disclosure aims to provide a display control device and a display control program that can suppress erroneous corrections caused by road gradients, even when the detection value of a gyro sensor is used to correct the display position of a virtual image. [Means for solving the problem]

[0006] In order to achieve the above object, one disclosed aspect is a display control device used in a vehicle (Am) for controlling the display of a virtual image (Vi) superimposed on a foreground seen by an occupant, the display control device comprising: a gyro sensor (63) for detecting a change in attitude of the vehicle in a pitch direction; is the integral value of the output signal that has passed through the high-pass filter (71a) applied to the gyro sensor. a display correction unit (74) that performs correction processing to correct a deviation in the display position of the virtual image relative to the foreground caused by a change in posture based on the detected value; and a display correction unit (74) that acquires gradient information related to the gradient of the road on which the vehicle is traveling. and determine whether the vehicle has entered a gradient section (GS). and a gradient information acquisition unit (73) for acquiring gradient information, and the display correction unit changes the content of the correction process according to the gradient information. After the vehicle enters a gradient section, the correction of the display position by the correction process is suspended, and the correction of the display position is resumed based on the return of the detected value to a predetermined value for determining that the influence of the gradient change on the detected value has ended. The display control device is a display control device that

[0007] Another disclosed aspect is a display control program used in a vehicle (Am) for controlling the display of a virtual image (Vi) superimposed on a foreground seen by a passenger, the program ... is the integral value of the output signal that has passed through the high-pass filter (71a) applied to the gyro sensor. (S13), and based on the detected value, a correction process is performed to correct a deviation in the display position of the virtual image relative to the foreground caused by a change in posture (S14, S15), and gradient information related to the gradient of the road on which the vehicle is traveling is obtained. It is determined whether the vehicle has entered a gradient section (GS) (S31, S32). Change the content of the correction process according to the gradient information Shi(S 33), After the vehicle enters the gradient section, the correction of the display position by the correction process is interrupted, and the correction of the display position is resumed when the detected value returns to a predetermined value for determining that the influence of the gradient change on the detected value has ended (S39). The display control program causes at least one processing unit (11) to execute processing including the above.

[0008] In these aspects, the content of the correction process for correcting the display position of the virtual image based on the detection value of the gyro sensor is changed according to gradient information related to the gradient of the road on which the vehicle is traveling. Therefore, it is possible to separate information detecting a change in posture due to the road gradient from the detection value of the gyro sensor. As a result, even in an aspect in which the detection value of the gyro sensor is used to correct the display position of the virtual image, erroneous correction due to the road gradient can be suppressed.

[0009] Note that the reference numbers in parentheses above and in the claims merely indicate an example of the correspondence with the specific configurations in the embodiments described below, and do not in any way limit the technical scope. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an overall view of an in-vehicle network including an HMI-ECU according to a first embodiment of the present disclosure. [Figure 2] 1A and 1B are diagrams for explaining how a virtual image is displayed by projecting display light from a HUD. [Figure 3] FIG. 10 is a diagram showing an example of gradient information based on three-dimensional map data. [Figure 4] FIG. 10 is a diagram illustrating an example of gradient information based on detection information from a front camera. [Figure 5] 10 is a flowchart showing details of a data generation process performed by the HMI-ECU. [Figure 6] 10A and 10B are diagrams showing, in comparison, differences in the detection values ​​of the gyro sensor during an accelerating state when the cutoff frequency is changed. [Figure 7] 10A and 10B are diagrams showing a comparison of differences in the detection values ​​of the gyro sensor in a gradient section when the cutoff frequency is changed. [Figure 8] 10 is a flowchart showing details of gradient adaptation processing performed by the HMI-ECU. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments will be described with reference to the drawings. Note that corresponding components in each embodiment are given the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment described previously can be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments can also be partially combined together even if not explicitly stated, as long as there is no particular problem with the combination.

[0012] (First embodiment) 1 and 2, an HMI (Human Machine Interface)-ECU (Electronic Control Unit) according to a first embodiment of the present disclosure is a display control device used in a vehicle Am. The HMI-ECU 100 is mounted on the vehicle Am together with a display device such as a HUD (Head Up Display) 20, and together with these display devices, etc., constitutes a display system for the vehicle Am.

[0013] The HMI-ECU 100 is communicatively connected to a communication bus 99 of an in-vehicle network 1 mounted on a vehicle Am. The HMI-ECU 100 is one of a plurality of nodes provided in the in-vehicle network 1. A driver monitor 30, a locator ECU 40, an ADAS (Advanced Driver Assistance System)-ECU 50, a cruise control ECU 60, and the like are connected to the communication bus 99 of the in-vehicle network 1. These nodes connected to the communication bus 99 can communicate with each other. Specific nodes among these devices and ECUs may be electrically connected directly to each other and can communicate without going through the communication bus 99.

[0014] The driver monitor 30 includes a near-infrared light source, a near-infrared camera, and a control unit for controlling them. The driver monitor 30 is installed, for example, on the top surface of the steering column or the top surface of the instrument panel, with the near-infrared camera facing the headrest of the driver's seat. The driver monitor 30 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 driver's face position, face orientation, eye point EP position, and line of sight from the captured image. The driver monitor 30 provides the information extracted by the control unit to the HMI-ECU 100, the ADAS-ECU 50, etc. as driver status information.

[0015] The locator ECU 40 generates highly accurate position information of the vehicle Am by composite positioning that combines multiple pieces of acquired information. The locator ECU 40 is connected to a GNSS (Global Navigation Satellite System) receiver 41 and a three-dimensional map database (hereinafter referred to as a 3D map DB) 42. The GNSS receiver 41 receives positioning signals transmitted from multiple artificial satellites (positioning satellites). The 3D map DB 42 is mainly composed of a non-volatile storage medium. The 3D map DB 42 stores map (High Definition map) data with higher accuracy than the map data used for route guidance by the navigation device. The HD map data stored in the 3D map DB 42 contains detailed information at least in the height direction (z direction). The locator ECU 40 reads out HD map data of the area around the current position from the 3D map DB 42 and provides it as locator information to the ADAS-ECU 50, the HMI-ECU 100, etc., along with the position information and direction information of the vehicle Am. The function of the locator ECU 40 that provides the locator information may be implemented in a navigation device mounted on the vehicle Am.

[0016] The ADAS-ECU 50 is an in-vehicle ECU that realizes driving assistance functions that assist the driver in driving operations. The ADAS-ECU 50 enables advanced driving assistance or partial autonomous driving at approximately level 2 in the autonomous driving levels defined by the Society of Automotive Engineers of America. Specifically, the ADAS-ECU 50 realizes driving assistance functions such as ACC (Adaptive Cruise Control), LTC (Lane Trace Control), and LCA (Lane Change Assist). The ADAS-ECU 50 may be capable of autonomous driving at level 3 or higher, where the system is the main controller.

[0017] The ADAS-ECU 50 is connected to perimeter monitoring sensors (autonomous sensors) mounted on the vehicle Am, such as a front camera 51 and a millimeter-wave radar 52. The front camera 51 outputs, as detection information, at least one of a captured image FP (see FIG. 4) capturing an area ahead of the vehicle Am and an analysis result of the captured image FP. The millimeter-wave radar 52 emits millimeter waves or quasi-millimeter waves toward an area ahead of the vehicle Am, a front-side area, a rear area, and a rear-side area, and receives waves reflected by moving objects, stationary objects, and the like, thereby generating detection information. The perimeter monitoring sensors may further include a lidar, a sonar, and the like.

[0018] The ADAS-ECU 50 recognizes moving and stationary objects around the vehicle by combining detection information from the front camera 51 and the millimeter-wave radar 52 with locator information acquired from the locator ECU 40. Specifically, the ADAS-ECU 50 recognizes vehicles ahead, behind, and to the sides of the vehicle Am, as well as dividing lines (white lines) on the road ahead, road signs, buildings along the road, utility poles, pedestrians, the sun, and the like. The ADAS-ECU 50 acquires information (target information) such as the relative positions and moving speeds (relative speeds) of the recognized moving and stationary objects through calculations. Based on the target information, the ADAS-ECU 50 cooperates with the cruise control ECU 60 to perform driving assistance control or autonomous driving control. The ADAS-ECU 50 provides the target information detected by the perimeter monitoring sensors or based on the detection information, and information indicating the operating status of the driving assistance control (hereinafter referred to as ADAS status information) to the HMI-ECU 100.

[0019] The driving control ECU 60 is an electronic control device that mainly includes a microcontroller. The driving control ECU 60 has at least the functions of a brake control ECU, a drive control ECU, and a steering control ECU. The driving control ECU 60 continuously controls the braking force of each wheel, the output of the on-board power source, and the steering angle based on operation commands based on the driver's driving operation or control commands from the ADAS-ECU 50.

[0020] The cruise control ECU 60 is connected to on-board sensors that detect the traveling state of the vehicle Am. The on-board sensors include a wheel speed sensor 61, an acceleration sensor 62, a gyro sensor 63, and the like. The wheel speed sensor 61 is provided, for example, at the hub of each wheel of the vehicle Am. The cruise control ECU 60 generates vehicle speed information indicating the current traveling speed of the vehicle Am based on the detection signal of the wheel speed sensor 61.

[0021] The acceleration sensor 62 and the gyro sensor 63 are provided near the center of gravity of the vehicle Am as, for example, an IMU (Inertial Measurement Unit). The acceleration sensor 62 detects at least acceleration acting in the forward / backward direction ZG of the vehicle Am. The acceleration sensor 62 may also be capable of detecting acceleration acting in the left / right direction SU of the vehicle Am and acceleration acting in the up / down direction JG of the vehicle Am.

[0022] The gyro sensor 63 is an on-board sensor that detects changes in the attitude of the vehicle Am, and detects at least an angular velocity in the pitch direction occurring around the pitch axis of the vehicle Am. The gyro sensor 63 may further detect an angular velocity in the yaw direction occurring around the yaw axis of the vehicle Am and an angular velocity in the roll direction occurring around the roll axis of the vehicle Am.

[0023] The cruise control ECU 60 generates acceleration information and angular velocity information based on the detection signals of the acceleration sensor 62 and the gyro sensor 63. The cruise control ECU 60 provides the HMI-ECU 100 with vehicle behavior information including vehicle speed information, acceleration information, and angular velocity information.

[0024] The longitudinal direction ZG, lateral direction SU, and vertical direction JG of the vehicle Am are defined with the vehicle Am at rest on a horizontal plane as a reference. Specifically, the longitudinal direction ZG is defined along the longitudinal direction (direction of travel) of the vehicle Am. The lateral direction SU is defined along the width direction of the vehicle Am. Furthermore, the vertical direction JG is defined along a direction perpendicular to the horizontal plane that defines the longitudinal direction ZG and the lateral direction SU. In addition, the pitch axis, yaw axis, and roll axis are defined along the lateral direction SU, vertical direction JG, and longitudinal direction ZG, respectively.

[0025] Next, the HUD 20 and the HMI-ECU 100 that constitute the display system will be described in further detail.

[0026] The HUD 20 is electrically connected to the HMI-ECU 100 and sequentially acquires video data generated by the HMI-ECU 100. Based on the video data, the HUD 20 presents various information related to, for example, a driving assistance function, an automatic driving function, and an in-vehicle function to a specific occupant (driver) of the vehicle Am using a virtual image Vi.

[0027] The HUD 20 is housed in a storage space within the instrument panel below the windshield WS. The HUD 20 projects display light, which is formed as a virtual image Vi, toward a projection range PA on the windshield WS. The display 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 visible through the projection range PA.

[0028] 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 displays each frame image of video data on the display surface of the LCD panel and transmits the display surface with backlight to emit display light that is focused as a virtual image Vi toward the magnifying optical system 22. The magnifying optical system 22 includes at least one optical element such as a concave mirror. The magnifying optical system 22 reflects and expands the display light emitted from the projector 21, and projects it into an upper projection range PA.

[0029] If the imaginary range in space where the HUD 20 can form a virtual image Vi is defined as an imaging plane IS, the field of view of the HUD 20 is determined based on a virtual line connecting the driver's eye point EP and the outer edge of the imaging plane IS. The field of view is the angular range in which the driver can view the virtual image Vi from the eye point EP. In the HUD 20, the horizontal field of view (e.g., about 10 to 12 degrees) is larger than the vertical field of view (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 of view.

[0030] The HUD 20 displays superimposed content and non-superimposed content as a virtual image Vi. The superimposed content is an AR (Augmented Reality) display object used for augmented reality display. The superimposed content is superimposed on a target ahead as seen by the driver. The display position of the superimposed content 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 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 is continuously maintained.

[0031] Non-overlapping content is a non-AR display object that is superimposed on the foreground, excluding the superimposed content. No superimposing target is set for non-overlapping content. The display position of non-overlapping content is set to a specific position within the projection range PA (angle of view). Non-overlapping content is displayed as if it is fixed relative to the vehicle components, such as the windshield WS.

[0032] The HMI-ECU 100 generates video data to be provided to the HUD 20, thereby controlling the display of a virtual image Vi by the HUD 20. The HMI-ECU 100 mainly includes a computer equipped with a processing unit 11, a RAM 12, a storage unit 13, an input / output interface, and a bus connecting these.

[0033] The processing unit 11 is hardware for arithmetic processing coupled to the RAM 12. The processing unit 11 includes 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 include a video RAM for generating images. The processing unit 11 accesses the RAM 12 to execute various processes for realizing the display control method of the present disclosure. The storage unit 13 includes a non-volatile storage medium. The storage unit 13 stores various programs (such as a display control program) executed by the processing unit 11.

[0034] The HMI-ECU 100 has a plurality of functional units that control the superimposed display of the virtual image Vi by the HUD 20 by executing a display control program stored in the storage unit 13 using the processing unit 11. Specifically, the HMI-ECU 100 has functional units such as a sensor information acquisition unit 71, a driver information acquisition unit 72, a recognition information acquisition unit 73, a display correction unit 74, and a drawing unit 75.

[0035] The sensor information acquisition unit 71 acquires vehicle behavior information provided by the cruise control ECU 60. Specifically, the sensor information acquisition unit 71 acquires a detection value of the gyro sensor 63 indicating a change in attitude in the pitch direction as attitude information indicating the vehicle attitude. The sensor information acquisition unit 71 is provided with a high-pass filter 71a applied to the gyro sensor 63. The high-pass filter 71a constitutes at least a part of a signal processing circuit that processes an output signal of the gyro sensor 63. The high-pass filter 71a attenuates signals in a band below a preset cutoff frequency and selectively passes signals in a band above the cutoff frequency. The cutoff frequency may be a fixed value or an adjustable value. The sensor information acquisition unit 71 acquires, as a detection value, an integral value of the output signal that has passed through the high-pass filter 71a. That is, the detection value of the gyro sensor 63 acquired by the sensor information acquisition unit 71 is a value indicating a pitch angle obtained by time-integrating the value of the angular velocity in the pitch direction.

[0036] The signal processing circuit including the high-pass filter 71a may be provided in the gyro sensor 63 or the cruise control ECU 60. In this configuration, the sensor information acquisition unit 71 directly acquires the detection value indicating the current pitch angle of the vehicle Am from the gyro sensor 63 or the cruise control ECU 60.

[0037] The driver information acquisition unit 72 acquires driver status information provided by the driver monitor 30. Based on the driver status information, the driver information acquisition unit 72 obtains coordinate information indicating the current position of the driver's eye point EP within the vehicle cabin.

[0038] The recognition information acquisition unit 73 acquires, as environmental information indicating the driving environment around the vehicle Am, locator information provided by the locator ECU 40 and detection information or target information provided by the ADAS-ECU 50. Based on the environmental information, the recognition information acquisition unit 73 determines the relative positions of the preceding vehicle, lane markings, etc. that are targets for superimposition of the superimposition content. In addition, based on the environmental information, the recognition information acquisition unit 73 acquires gradient information related to the gradient of the road on which the vehicle Am is traveling.

[0039] If an HD map is available for the road on which the vehicle Am is traveling, the recognition information acquisition unit 73 acquires gradient information based on the HD map (see FIG. 3). Based on coordinate points (z coordinates) included in the HD map, the recognition information acquisition unit 73 recognizes whether the road on which the vehicle Am is traveling is a substantially horizontal normal section HS or a gradient section GS with a longitudinal gradient. The gradient section GS may be an uphill section or a downhill section. Furthermore, the longitudinal gradient may vary in the gradient section GS. For example, if there is a longitudinal gradient of approximately ±0.5%, the recognition information acquisition unit 73 recognizes the section as a gradient section GS.

[0040] When the recognition information acquisition unit 73 recognizes that the road ahead of the vehicle has a longitudinal gradient, it identifies gradient change points GCPs at which the value of the longitudinal gradient changes. In addition to gradient change points GCPs at which a normal section HS transitions to a gradient section GS, the recognition information acquisition unit 73 also identifies transition points between gradient sections GS with different longitudinal gradients as gradient change points GCPs. That is, the recognition information acquisition unit 73 identifies gradient change points GCPs at which a road transitions from an uphill section to the next uphill section, a gradient change point GCP at which a road transitions from an uphill section to a downhill section, a gradient change point GCP at which a road transitions from a downhill section to the next downhill section, and a gradient change point GCP at which a road transitions from a downhill section to an uphill section.

[0041] When an HD map is not available for the road on which the vehicle is traveling, the recognition information acquisition unit 73 acquires gradient information based on detection information or target object information (see FIG. 4). The recognition information acquisition unit 73 identifies, based on changes in the shape of the lane markings captured in the image FP captured by the front camera 51, points where the slope (extension direction) of the lane markings changes, in other words, points where the rate of change in the width between the lane markings changes, as gradient change points GCPs. The recognition information acquisition unit 73 may also identify gradient change points GCPs based on changes in the position of targets located ahead.

[0042] The display correction unit 74 performs a correction process to correct a deviation in the display position of the virtual image Vi relative to the foreground caused by a change in the attitude of the vehicle Am, based on the attitude information acquired by the sensor information acquisition unit 71. In this correction process, the drawing position of the original image of the virtual image Vi is adjusted based on the attitude information in each frame image of the video data generated by the drawing unit 75. Of the superimposed content and non-superimposed content that can be displayed as the virtual image Vi, the display correction unit 74 applies the correction process only to the superimposed content.

[0043] The drawing unit 75 draws video data to be provided to the HUD 20. The drawing unit 75 selects information (content) to be presented to the driver using the virtual image Vi based on various information acquired from the communication bus 99, such as driver status information, vehicle behavior information, and ADAS status information. When displaying superimposed content, the drawing unit 75 draws the original image at the drawing position determined by the display correction unit 74.

[0044] The HMI-ECU 100 described above performs a data generation process (see FIG. 5) that provides video data to the HUD 20 through cooperation between the various functional units. The data generation process starts when the display system is started and continues until the power to the display system is turned off.

[0045] In S11 of the data generation process, the recognition information acquisition unit 73 determines the relative position of the target to be superimposed based on the detection information, target information, etc. In S12, the driver information acquisition unit 72 determines the current position of the driver's eye point EP. In S13, the sensor information acquisition unit 71 acquires the detection value of the gyro sensor 63 and determines attitude information (pitch angle, etc.) indicating the vehicle attitude. Note that if the content to be displayed does not include superimposed content, steps S11 to S13 may be omitted.

[0046] In S14, the display correction unit 74 determines the drawing position of the original image of each content to be displayed. When displaying superimposed content, the display correction unit 74 specifies the positional relationship between the superimposition target, eyepoint EP, and imaging plane IS based on the information acquired in S11 to S13. The display correction unit 74 determines the drawing position and drawing shape of the original image in each frame image based on the intersection position of the virtual line connecting the superimposition target and eyepoint EP with the imaging plane IS. In S15, the drawing unit 75 reflects the drawing position and drawing shape determined in S14 and draws the original image of each content in each frame image of the video data. The drawing unit 75 sequentially outputs video data consisting of a series of frame images to the HUD 20.

[0047] According to the above steps S14 and S15, the drawing position of the original image is adjusted based on the detection value of the gyro sensor 63, thereby making it possible to correct a deviation in the display position of the virtual image Vi caused by a change in the attitude of the vehicle Am due to acceleration or deceleration. Specifically, a vehicle Am in an accelerating state has a vehicle attitude with its front side raised higher than a vehicle Am in a steady state. In this case, in order to correctly superimpose the superimposed content on the superimposition target, the drawing position is adjusted to correct the display position of the superimposed content to a lower position than usual. Similarly, a vehicle Am in a decelerating state has a vehicle attitude with its front side lowered lower than a vehicle Am in a steady state. In this case, in order to correctly superimpose the superimposed content on the superimposition target, the drawing position is adjusted to set the display position of the superimposed content to a higher position than usual. As described above, by moving the display position of the superimposed content to offset the change in the attitude of the vehicle Am in the pitch direction, the superimposed content is maintained in a state where it is correctly superimposed on the superimposition target.

[0048] The cutoff frequency of the high-pass filter 71a is set so that changes in the pitch direction of the vehicle Am that occur due to acceleration or deceleration can be accurately detected. Specifically, if the cutoff frequency is appropriate, the pitch angle of the vehicle Am (see FIG. 6, Cutoff Frequency: Low) output as a detection value from the high-pass filter 71a will track the actual pitch angle (see FIG. 6, Pitch Angle True Value) when the vehicle Am is accelerating. On the other hand, if the cutoff frequency is higher than the appropriate value, the pitch angle of the vehicle Am (see FIG. 6, Cutoff Frequency: Medium or High) output from the high-pass filter 71a will deviate from the actual pitch angle.

[0049] However, the frequency band of the attitude change in the pitch direction caused by acceleration / deceleration may largely overlap with the frequency band of the attitude change in the pitch direction caused by changes in road gradient. Therefore, if the cutoff frequency is set to follow the change in pitch angle caused by acceleration / deceleration (see Figure 7, Cutoff Frequency: Low), an attitude change in the pitch direction will be detected even when the vehicle Am in a steady state enters a gradient section GS. In this way, the detection value of the gyro sensor 63 may contain not only information on the attitude change detected due to acceleration / deceleration, but also information on the attitude change detected due to the road gradient.

[0050] If the cutoff frequency is set higher than an appropriate value so as not to detect posture changes due to road gradient, posture changes due to acceleration / deceleration will not be detected (see Fig. 6 and Fig. 7 Cutoff frequency: medium or high). As described above, it is difficult to distinguish between posture changes due to acceleration / deceleration and posture changes due to changes in road gradient simply by optimizing the cutoff frequency.

[0051] As explained above, in the estimation of attitude change using the gyro sensor 63, if a cutoff frequency capable of detecting attitude change due to acceleration / deceleration is set, attitude change due to change in road gradient will also be detected. Therefore, the HMI-ECU 100 performs gradient adaptation processing (see FIG. 8) that changes the content of the correction processing (see S14 in FIG. 5) as a process for distinguishing between attitude change due to acceleration / deceleration and attitude change due to change in road gradient. The gradient adaptation processing, like the data generation processing (see FIG. 5), is started when the display system is started and continues until the power of the display system is turned off.

[0052] In S31 of the gradient response processing, the recognition information acquisition unit 73 determines whether or not there is a gradient section GS ahead of the vehicle based on at least one of the locator information, detection information, and target information. If there is a gradient section GS ahead of the vehicle, the recognition information acquisition unit 73 acquires gradient information related to the gradient of the gradient section GS. Specifically, the recognition information acquisition unit 73 determines, as gradient information, the magnitude of the longitudinal gradient of the gradient section GS and the position of the gradient change point GCP where the gradient section GS starts.

[0053] In S32, the recognition information acquisition unit 73 determines whether the vehicle Am has passed a gradient change point GCP, in other words, whether the vehicle Am has entered a gradient section GS. If it is determined in S32 that the vehicle Am has passed a gradient change point GCP, the display correction unit 74 changes the content of the correction process in accordance with the gradient information in S33. Specifically, the display correction unit 74 suspends the correction of the display position through the correction process based on the determination that the vehicle Am has entered a gradient section GS. Specifically, in the correction process during a gradient, for example, the drawing position of the original image of the superimposed content is fixed. At this time, the process of the display correction unit 74, which calculates the optimal drawing position of the original image according to the latest acquired information, may be suspended, or the process of the drawing unit 75, which reflects the latest drawing position at the frame image drawing stage, may be suspended. As a result, the virtual image Vi (superimposed content) is fixed at a specific position within the angle of view.

[0054] In S34, the recognition information acquisition unit 73 determines whether or not there is a gradient change within the gradient section GS. If there is a change in the gradient mode within the gradient section GS, the sensor information acquisition unit 71 resets the high-pass filter 71a in S35. The sensor information acquisition unit 71 performs a reset process for the high-pass filter 71a when the vehicle passes a gradient change point GCP identified within the gradient section GS. In this reset process, past information accumulated in the high-pass filter 71a is deleted, and the integrated value of the output signal of the gyro sensor 63 is returned to zero. As a result, the vehicle attitude at the time of resetting becomes the reference value (zero) of the pitch angle. Even when the reset process is performed, the correction process during the gradient is maintained as it is. On the other hand, if it is determined that there is no gradient change, the recognition information acquisition unit 73 skips S35.

[0055] In S36, the recognition information acquisition unit 73 determines whether the influence of the gradient change on the detection value of the gyro sensor 63 has ended. Specifically, the recognition information acquisition unit 73 determines whether the detection value of the gyro sensor 63 has returned to a predetermined value. If the detection value has been reset due to continuous gradient changes, the recognition information acquisition unit 73 determines whether the detection value after reset has returned to the predetermined value. The predetermined value is set to, for example, the zero point. A position slightly shifted from the zero point to the positive or negative side may also be set as the predetermined value. The recognition information acquisition unit 73 determines that the detection value has returned to the predetermined value when the detection value, which has risen to a specific side (the positive side in FIG. 7) due to the road gradient, passes the zero point, drops to the opposite side (the negative side in FIG. 7), and then converges to the zero point again.

[0056] If it is determined in S36 that the effect of the gradient change has ended due to the return of the detection value of the gyro sensor 63 to a predetermined value, the display correction unit 74 ends the correction process during the gradient and switches to normal correction process in S39. This restarts the correction of the display position, and the virtual image Vi (superimposed content) resumes following the superimposed object. At this time, the display correction unit 74 sets an upper limit (for example, n pixels per second) on the movement speed at which the display position is moved. As an example, the upper limit of the movement speed is set in the form of n pixels per second, etc. This prevents the virtual image Vi from suddenly moving, such as jumping toward the superimposed object.

[0057] On the other hand, if it is determined in S36 that the influence of the gradient change on the detection value is continuing, the recognition information acquisition unit 73 determines in S37 whether the gradient section GS has ended and the vehicle has returned to a flat road (normal section HS). If the gradient section GS is continuing, the processes of S33 to S36 are performed again. On the other hand, if it is determined in S37 that the gradient section GS has ended, the recognition information acquisition unit 73 prepares for transition to normal control in S38. In preparation for transition to normal control, the high-pass filter 71a is reset as a process for removing the influence of the gradient change from the detection value of the gyro sensor 63. Then, in S39, the display correction unit 74 ends the correction process during the gradient and starts normal correction process.

[0058] In the first embodiment described above, the content of the correction process for correcting the display position of the virtual image Vi using the detection value of the gyro sensor 63 is changed according to gradient information related to the gradient of the road on which the vehicle Am travels. Therefore, it is possible to separate information detecting a change in posture due to the road gradient from the detection value of the gyro sensor 63. As a result, even in an embodiment in which the detection value of the gyro sensor 63 is used to correct the display position of the virtual image Vi, erroneous correction due to the road gradient can be suppressed.

[0059] Additionally, in the first embodiment, when it is determined based on the gradient information that the vehicle Am has entered a gradient section GS, the correction of the display position by the correction process is suspended. That is, in the first embodiment, detection values ​​that contain a large amount of detection information on posture changes due to the road gradient are temporarily excluded from the targets used in the correction process. This change in the content of the correction process makes it possible to reliably separate the detection information on posture changes due to the road gradient, thereby further suppressing erroneous corrections caused by the road gradient. As a result, after passing a gradient change point GCP, a situation in which the movement of the virtual image Vi is unable to correctly track the superimposed target and causes the driver to feel uncomfortable is less likely to occur.

[0060] In the first embodiment, the sensor information acquisition unit 71 acquires, as a detection value, an integral value of an output signal that has passed through the high-pass filter 71a applied to the gyro sensor 63. The display correction unit 74 then resumes correcting the display position based on the return of the detection value to a predetermined value (zero point). As a result, immediately after entering the gradient section GS, erroneous correction due to the road gradient can be suppressed, and after the vehicle posture has stabilized in the gradient section GS, the display position of the virtual image Vi can be corrected to an appropriate position.

[0061] Furthermore, in the first embodiment, when the gradient changes in the gradient section GS, the sensor information acquisition unit 71 resets the detection value of the gyro sensor 63. Then, the display correction unit 74 resumes correcting the display position based on the detection value returning to a predetermined value (zero point) after the reset. Therefore, even in a scene where the vehicle is traveling in a gradient section GS where the gradient changes continuously, the display correction unit 74 can exclude detection values ​​that contain a lot of detection information about posture changes due to the road gradient from the detection values ​​to be used in the correction process. Furthermore, when the vehicle posture stabilizes, the display correction unit 74 can resume correcting the display position of the virtual image Vi.

[0062] Additionally, in the first embodiment, an upper limit is set on the speed at which the display position is moved during the correction process in the gradient section GS. Therefore, after the display position correction is resumed, the virtual image Vi can smoothly move toward an appropriate position relative to the superimposition target. As a result, a sudden movement of the virtual image Vi is less likely to cause the driver to feel uncomfortable.

[0063] In the first embodiment, superimposed content, the display position of which is associated with a superimposed object present in the foreground, and non-superimposed content, the display position of which is not associated with a superimposed object, are displayed as virtual images Vi. The display correction unit 74 applies correction processing only to the superimposed content, out of the superimposed content and non-superimposed content. This reduces the likelihood of unnecessary movement of the non-superimposed content causing discomfort to the driver.

[0064] In the first embodiment, the recognition information acquisition unit 73 corresponds to the "gradient information acquisition unit", the drawing unit 75 corresponds to the "content generation unit", and the HMI-ECU 100 corresponds to the "display control device".

[0065] Second Embodiment The second embodiment of the present disclosure is a modified example of the first embodiment. In the second embodiment, the content of the correction process during the gradient that is started after entering the gradient section GS is different from that in the first embodiment, and the correction of the display position of the virtual image Vi is continued even during the correction process during the gradient. Hereinafter, the details of the correction process during the gradient according to the second embodiment will be described based on FIG. 8 and with reference to FIGS. 1 to 7.

[0066] In the correction process during the gradient (S33), the display correction unit 74 estimates the amount of attitude change in the pitch direction due to the gradient as the gradient influence component. The amount of attitude change that constitutes the gradient influence component substantially coincides with the magnitude of the gradient (inclination angle) in the gradient section GS. Therefore, the recognition information acquisition unit 73 acquires a value indicating the inclination angle of the gradient section GS as gradient information based on the HD map (3D map data) and provides the acquired inclination angle value to the display correction unit 74. The display correction unit 74 estimates the gradient influence component using the inclination angle based on the HD map.

[0067] For roads without HD maps, the recognition information acquisition unit 73 can acquire a value indicating the inclination angle of the gradient section GS as gradient information based on detection information or target object information. As an example, the recognition information acquisition unit 73 geometrically calculates the inclination angle of the gradient section GS ahead of the vehicle based on the shape of the lane markings in a captured image FP (see FIG. 4 ) taken before the vehicle reaches the gradient change point GCP. To calculate the inclination angle, a captured image FP taken in a steady state where the pitch angle is essentially zero is preferentially used. When calculating the inclination angle using a captured image FP taken in a non-steady state, the recognition information acquisition unit 73 corrects the inclination angle of the forward gradient using the pitch angle of the vehicle Am at the time of capture. Using the inclination angle thus acquired, the display correction unit 74 estimates the gradient influence component.

[0068] The display correction unit 74 obtains a correction change amount by subtracting the gradient-influenced component from the pitch direction attitude change amount based on the detection value of the gyro sensor 63. The correction change amount is the attitude change amount in the pitch direction mainly caused by acceleration / deceleration of the vehicle Am, and is the pitch angle relative to the road surface while traveling. The display correction unit 74 corrects the display position of the virtual image Vi using the correction change amount. When both superimposed content and non-superimposed content are displayed while traveling through a gradient section GS, the display correction unit 74 moves the non-superimposed content together with the superimposed content in the correction process for the gradient section GS. Note that when traveling through a normal section HS, the non-superimposed content may or may not be moved together with the superimposed content.

[0069] The display correction unit 74 uses the elapsed time after passing the gradient change point GCP to determine whether the influence of the gradient change on the detection value of the gyro sensor 63 has ended (S36). More specifically, due to the characteristics of the high-pass filter 71a, the detection value returns to the zero point after a predetermined time has passed since passing the gradient change point GCP (see the right side of Figure 7). The time required for returning to the zero point is generally constant regardless of the magnitude of the gradient. Therefore, the display correction unit 74 presets a predetermined time (hereinafter referred to as the restart time) that is slightly longer than the time required for returning to the zero point as a threshold value in accordance with the characteristics of the high-pass filter 71a. The display correction unit 74 estimates that the detection value has returned to the zero point when the restart time has passed after passing the gradient change point GCP, and determines that the influence of the gradient change has ended (S36: YES).

[0070] Here, also in the second embodiment, when the gradient changes in the gradient section GS (S34: YES), the sensor information acquisition unit 71 resets the detection value of the gyro sensor 63. The display correction unit 74 sets an upper limit on the movement speed of the drawing position, i.e., the movement speed of the display position, so that the drawing position of the original image does not change discontinuously due to discontinuous changes in the detection value caused by the reset process. This allows the virtual image Vi to continue moving smoothly even if the gradient changes while the display position correction is continued in the gradient section GS.

[0071] Additionally, when the gradient changes during the gradient section GS, the display correction unit 74 extends the restart time for determining that the effect of the gradient change has ended by updating it. Furthermore, the recognition information acquisition unit 73 updates the point for determining the end of the gradient section GS. As a result, when the restart time has elapsed after the filter reset or when the gradient of the change in gradient ends, the correction process during the gradient is terminated and switched to normal correction process (S39). As a result, the correction of the display position using the correction change amount is terminated, and normal correction based on the detection value of the gyro sensor 63 is resumed.

[0072] The second embodiment described so far also has the same effect as the first embodiment, and can separate information on detected posture changes caused by road gradients from the detection values ​​of the gyro sensor 63. Therefore, even in an embodiment in which the detection values ​​of the gyro sensor 63 are used to correct the display position of the virtual image Vi, erroneous correction caused by road gradients can be suppressed.

[0073] Additionally, in the second embodiment, after the vehicle Am enters the gradient section GS, the display correction unit 74 estimates the amount of attitude change in the pitch direction due to the gradient as a gradient-influence component. Then, the display correction unit 74 corrects the display position of the virtual image Vi using a correction change amount obtained by subtracting the gradient-influence component from the amount of attitude change in the pitch direction based on the detected value. Such correction processing during a gradient makes it possible to reliably separate information detecting attitude changes due to the road gradient from the detection value of the gyro sensor 63. As a result, even if the display position correction is continued after entering the gradient section GS, erroneous correction due to the road gradient can be further suppressed.

[0074] In the second embodiment, a value indicating the magnitude of the gradient of the gradient section GS is acquired as gradient information based on the 3D map data. The display correction unit 74 then estimates the gradient influence component using the gradient information based on the 3D map data. This process allows the display correction unit 74 to accurately estimate the gradient influence component. Therefore, accurate correction of the display position can be performed even after entering the gradient section GS.

[0075] Furthermore, in the second embodiment, a value indicating the magnitude of the gradient of the gradient section GS is acquired as gradient information based on the recognition results of the front camera 51 mounted on the vehicle Am. The display correction unit 74 then estimates the gradient influence using the gradient information based on the recognition results. With this processing, even on roads for which HD maps are not available, the display correction unit 74 can acquire the correction change amount and continue to correct the display position based on the acquired correction change amount.

[0076] The recognition information acquisition unit 73 may estimate the size of the gradient section GS using the recognition result from the millimeter wave radar 52 instead of the recognition result from the front camera 51, etc. As an example, the recognition information acquisition unit 73 can acquire the inclination angle of the forward gradient based on the relative position of the forward vehicle, etc. in the up-down direction JG.

[0077] In addition, the display correction unit 74 of the second embodiment terminates the correction of the display position using the correction change amount based on the return of the detection value to the zero point. Therefore, during the period when the gradient influence increases immediately after entering the gradient section GS, erroneous correction due to the road gradient is effectively suppressed. Furthermore, because the correction process switches to normal correction processing when the detection value returns to the zero point, significant movement of the virtual image Vi due to control transition is unlikely to occur.

[0078] Also in the second embodiment, when the gradient changes in a gradient section GS, the sensor information acquisition unit 71 resets the detection value of the gyro sensor 63. Then, the display correction unit 74 ends the correction of the display position using the correction change amount based on the fact that the detection value after the reset has returned to zero. As a result, even in a gradient section GS where the gradient changes continuously, the display correction unit 74 can continue correcting the display position excluding the influence of the gradient. Then, when the vehicle posture stabilizes, the display correction unit 74 can resume the normal correction process.

[0079] Furthermore, in the second embodiment, in the correction process in the gradient section GS, the display correction unit 74 sets an upper limit on the movement speed at which the display position is moved. Therefore, even if the detection value is reset due to passing through a gradient change point GCP in the gradient section GS, the display correction unit 74 can continue to smoothly move the virtual image Vi. Therefore, a situation in which discontinuous movement of the virtual image Vi causes discomfort to the driver is unlikely to occur.

[0080] Additionally, in the second embodiment, when both superimposed content and non-superimposed content are displayed, the display correction unit 74 moves the non-superimposed content together with the superimposed content during correction processing in the gradient section GS. As a result, the non-superimposed content can be moved to a position that does not interfere with the movement of the superimposed content. As a result, it is possible to avoid a situation in which the superimposed content, which has moved significantly, overlaps with the non-superimposed content, resulting in an unnatural virtual image display.

[0081] In the second embodiment, the front camera 51 and the millimeter wave radar 52 correspond to the "autonomous sensor."

[0082] (Third embodiment) The third embodiment of the present disclosure is another modified example of the first embodiment. In the third embodiment, the method for determining whether the vehicle has entered a gradient section GS and the content of the correction process during the gradient that is performed after the vehicle has entered the gradient section GS are different from those of the first and second embodiments. Below, the changes in the gradient response process according to the third embodiment from the first embodiment will be described based on FIG. 8 and with reference to FIGS. 1 to 7.

[0083] The recognition information acquisition unit 73 integrally determines whether a gradient section GS exists (S31) and whether a gradient change point GCP has been passed (S32). More specifically, the recognition information acquisition unit 73 obtains vehicle speed information and angular velocity information in the pitch direction. If the angular velocity in the pitch direction changes while the traveling speed of the vehicle Am remains unchanged, the recognition information acquisition unit 73 determines that a gradient section GS exists and that the gradient change point GCP has been passed.

[0084] In the correction process during the gradient (S33), the sensor information acquisition unit 71 resets the high-pass filter 71a and changes the cutoff frequency. The reset process deletes past information stored in the high-pass filter 71a, and temporarily resets the integrated value of the output signal from the gyro sensor 63 to zero. The sensor information acquisition unit 71 then changes the cutoff frequency of the high-pass filter 71a. The driver information acquisition unit 72 increases the cutoff frequency to a value (see FIG. 7, Cutoff Frequency: High) at which posture changes due to the road gradient are no longer reflected in the detected value. As a result, posture changes due to acceleration or deceleration are less likely to be reflected in the detected value from the gyro sensor 63 (see FIG. 6, Cutoff Frequency: High). Therefore, in the correction process during the gradient section GS, the correction of the display position is essentially suspended.

[0085] If the angular velocity has changed in the opposite direction to when entering the gradient section GS, the recognition information acquisition unit 73 determines that the gradient section GS has ended (S37: YES). Even in this case, the sensor information acquisition unit 71 performs a reset process for the high-pass filter 71a in preparation for transition to normal control (S38). Furthermore, the sensor information acquisition unit 71 performs a process for lowering the cutoff frequency of the high-pass filter 71a to return it to the normal value. As a result, switching from the correction process during the gradient to the normal correction process is completed (S39), and correction of the display position of the virtual image Vi that reflects the posture change accompanying acceleration / deceleration is started. Note that in the third embodiment, steps S34 to S36 are omitted.

[0086] The third embodiment described so far also achieves the same effect as the first embodiment, and can separate information on detected posture changes caused by road gradients from the detection values ​​of the gyro sensor 63. Specifically, during a period when posture changes caused by road gradients are dominant, the posture changes are less likely to be reflected in the detection values ​​of the gyro sensor 63. As a result, even in an embodiment in which the detection values ​​of the gyro sensor 63 are used to correct the display position of the virtual image Vi, erroneous correction caused by road gradients can be suppressed.

[0087] (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 that does not deviate from the gist of the present disclosure.

[0088] In a first modification of the above embodiment, the functions of the HMI-ECU 100 are incorporated into the control unit of the HUD 20. In this first modification, the control unit of the HUD 20 corresponds to the "display control device."

[0089] In the HUD 20 of the above embodiment, the display position of the virtual image Vi is corrected by a process of shifting the drawing position of the original image drawn in the frame image. In contrast, in the second modification of the above embodiment, the display position of the virtual image Vi is corrected by controlling the translation or rotation of the optical elements included in the magnifying optical system 22.

[0090] The vehicle Am according to the third modification of the above embodiment is provided with a height sensor as an on-board sensor. Even in a configuration including a height sensor as in the third modification, the present disclosure is applicable as long as the display position of the virtual image Vi is corrected mainly based on the detection value of the gyro sensor 63.

[0091] In a fourth modification of the above embodiment, the IMU including the acceleration sensor 62 and the gyro sensor 63 is connected to the locator ECU 40. In the fourth modification, a signal processing circuit including a high-pass filter 71a is also provided in the IMU or the locator ECU 40. The sensor information acquisition unit 71 acquires the detection value of the gyro sensor 63 from the locator ECU 40 as locator information. In a fifth modification of the above embodiment, the HMI-ECU 100 or the HUD 20 is provided with a dedicated gyro sensor 63 for correcting the display position of the virtual image Vi.

[0092] In the sixth modification of the above embodiment, real-time detection of the eye point EP by the driver monitor 30 is omitted. The HMI-ECU according to the sixth modification corrects the display position of the virtual image Vi based on the position information of the preset eye point EP.

[0093] In the above embodiment, the form of the storage medium (non-transitory tangible storage medium) that stores the display control program may be changed as appropriate. Such a storage medium is not limited to a configuration provided on a circuit board, but may be provided in the form of a memory card or the like, inserted into a slot, and electrically connected to the control circuit of the HMI-ECU 100. Furthermore, the storage medium may be an optical disk, a hard disk drive, or the like, from which the program is copied to the HMI-ECU 100.

[0094] Vehicles equipped with the above-described display system are not limited to ordinary private passenger cars, but may also be rental cars, manned taxis, ride-sharing vehicles, freight vehicles, buses, etc. Furthermore, vehicles equipped with the display system may be right-hand drive vehicles or left-hand drive vehicles. Furthermore, the traffic environment in which the vehicle travels may be one based on left-hand traffic or one based on right-hand traffic. The display control according to the present disclosure may be optimized as appropriate according to the road traffic laws of each country and region, as well as the position of the vehicle's steering wheel.

[0095] The controller and methods described herein may be implemented by a special-purpose computer comprising a processor programmed to perform one or more functions embodied in a computer program. Alternatively, the apparatus and methods described herein may be implemented by special-purpose hardware logic circuitry. Alternatively, the apparatus and methods described herein may be implemented by one or more special-purpose computers comprising a processor executing a computer program in combination with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory storage medium. [Explanation of symbols]

[0096] Am: vehicle, GS: gradient section, Vi: virtual image, 11: processing unit, 51: front camera (autonomous sensor), 52: millimeter-wave radar (autonomous sensor), 63: gyro sensor, 71: sensor information acquisition unit, 71a: high-pass filter, 73: recognition information acquisition unit (gradient information acquisition unit), 74: display correction unit, 75: drawing unit (content generation unit), 100: HMI-ECU (display control device)

Claims

1. A display control device used in a vehicle (Am) and controlling the display of a virtual image (Vi) superimposed on a foreground visible to an occupant, a sensor information acquisition unit (71) that acquires, as a detection value of a gyro sensor (63) that detects an attitude change in a pitch direction occurring in the vehicle, an integral value of an output signal that has passed through a high-pass filter (71 a) applied to the gyro sensor; a display correction unit (74) that performs a correction process to correct a deviation of a display position of the virtual image relative to the foreground caused by the posture change based on the detection value; a gradient information acquisition unit (73) that acquires gradient information related to the gradient of a road on which the vehicle is traveling and determines whether the vehicle has entered a gradient section (GS), The display correction unit changing the content of the correction process in accordance with the gradient information; After the vehicle enters the gradient section, the correction of the display position by the correction process is interrupted; The display control device resumes correcting the display position based on the detection value returning to a predetermined value for determining that the influence of gradient changes on the detection value has ended.

2. the sensor information acquisition unit resets the detection value when the gradient state in the gradient section changes; The display control device according to claim 1 , wherein the display correction unit resumes the correction of the display position when the detected value returns to the predetermined value after resetting.

3. The display control device according to claim 1 , wherein the display correction unit sets an upper limit on a moving speed at which the display position is moved in the correction process in the gradient section.

4. a content generation unit (75) that displays, as the virtual image, superimposed content whose display position is associated with a superimposed object present in the foreground and non-superimposed content whose display position is not set with the superimposed object, 4. The display control device according to claim 1, wherein the display correction unit applies the correction process only to the superimposed content out of the superimposed content and the non-superimposed content.

5. A display control program used in a vehicle (Am) for controlling display of a virtual image (Vi) superimposed on a foreground visible to an occupant, An integral value of an output signal that has passed through a high-pass filter (71 a) applied to the gyro sensor is obtained as a detection value of the gyro sensor (63) that detects a change in attitude in the pitch direction that occurs in the vehicle (S13). Based on the detected value, a correction process is performed to correct a deviation of the display position of the virtual image relative to the foreground caused by the change in posture (S14, S15). Gradient information relating to the gradient of the road on which the vehicle is traveling is acquired, and it is determined whether the vehicle has entered a gradient section (GS) (S31, S32); The content of the correction process is changed according to the gradient information (S33). After the vehicle enters the gradient section, the correction of the display position by the correction process is interrupted; When the detected value returns to a predetermined value for determining that the influence of the gradient change on the detected value has ended, the correction of the display position is resumed (S39). A display control program that causes at least one processing unit (11) to execute processing including the above.

Images