Mobile body display system

Abstract

The present invention corrects the display position of an image during acceleration / deceleration so as not to cause an operator a sense of visual incongruity. A mobile body display system 10 makes a display unit display an image such that the image is superimposed over an actual view. The mobile body display system 10 comprises an information acquisition means 230 that acquires angular velocity information and acceleration information, a control means 210 that configures correction information for correcting the display position of the image on the basis of an angular velocity from the angular velocity information and an acceleration from the acceleration information as acquired a prescribed time before the time at which the angular velocity information is acquired, and a display position adjustment means 100 that adjusts the display position of the image on the basis of the correction information.

Description

Mobile display system

[0001] The present disclosure relates to a display system for a moving body that superimposes an image (virtual object) on an actual scene in the moving direction of the moving body.

[0002] A display system for a moving body, such as a vehicle, capable of displaying driving assistance information on a windshield or the like in front of the vehicle (in the direction of travel of the vehicle) when driving the moving body has been developed. A head-up display (HUD) device is known as an example of a display system for a moving body. A head-up display device is a device that displays an augmented reality (AR) image by superimposing (overlapping) an image (virtual object) on a real scene in front of the vehicle, thereby adding and emphasizing information from the image (virtual object) to the real scene or real objects present in the real scene. By superimposing an image on the real scene in front of the vehicle, driving assistance information can be accurately provided while minimizing eye movement of the driver of the vehicle, contributing to safe and comfortable vehicle operation.

[0003] In recent head-up display devices, in order to suppress a relative positional shift between an image (virtual object) and a real scene that occurs due to a change in the vehicle's attitude, a process is performed to move (shift) the display position of the image in accordance with the change in the vehicle's attitude (see, for example, Patent Document 1). As a result, even if a change in the vehicle's attitude occurs, the relative positional relationship between the image and the real scene is maintained (the positional shift between the image and the real scene is suppressed), and it becomes possible to harmonize the image with the real scene.

[0004] International Publication No. 2020 / 208883

[0005] However, in the head-up display device described in Patent Document 1, the vehicle attitude is calculated based on the angular velocity detected by a gyro sensor, and a process of moving the display position of the image based on the calculated vehicle attitude (correction process based on the angular velocity of the display position) is performed. Therefore, if the detected angular velocity is constant, the correction amount based on the angular velocity converges to 0 over time, and the display position of the image is no longer corrected.

[0006] For example, even if the vehicle posture is tilted forward, such as when the vehicle is decelerating, if the angular velocity becomes 0 (converges to 0) due to the deceleration change, correction processing for the display position of the image will no longer be performed, and the display position of the image may be shifted downward relative to the actual scene, causing the image to appear sunken. If the image is displayed sunken relative to the actual scene in this way, there is a problem in that it may give the driver a visually uncomfortable feeling.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a display system for a moving body that is less likely to cause visual discomfort to the driver by correcting the display position of an image (virtual object) when the moving body accelerates or decelerates.

[0008] In order to solve the above problem, the display system for a moving body in the first embodiment is a display system for a moving body that displays an image on a display unit installed in the direction of travel of the moving body so as to be superimposed on an actual scene in the direction of travel of the moving body, and is characterized by comprising: an information acquisition means that acquires angular velocity information consisting of information indicating the angular velocity of the moving body and acceleration information consisting of information indicating the acceleration of the moving body from an attitude detection means installed on the moving body; a control means that sets correction information for correcting the display position of an image to be displayed on the display unit based on the angular velocity of the angular velocity information acquired by the information acquisition means and the acceleration of the acceleration information acquired a predetermined time before the time when the angular velocity information was acquired by the information acquisition means; and a display position adjustment means that adjusts the display position of the image displayed on the display unit based on the correction information set by the control means.

[0009] In a second embodiment that can be dependent on the first embodiment, the display system for a moving body has a recording means for recording the acceleration information acquired by the information acquisition means in chronological order, and the control means extracts from the recording means acceleration information acquired a predetermined time before the time when the angular velocity information was acquired by the information acquisition means, and sets the correction information based on the acceleration of the extracted acceleration information and the angular velocity of the angular velocity information acquired by the information acquisition means.

[0010] In a third embodiment of the display system for a moving body that can be dependent on the first or second embodiment, the time from when the angular velocity information is acquired by the information acquisition means to when the control means sets the correction information using the angular velocity of the angular velocity information and outputs it to the display position adjustment means is shorter than the time from when the acceleration information is acquired by the information acquisition means to when the control means sets the correction information using the acceleration of the acceleration information and outputs it to the display position adjustment means.

[0011] In a fourth embodiment of the display system for a moving body, which can be dependent on the first to third embodiments, the predetermined time period is lengthened when the increase in acceleration is large, and shortened when the increase in acceleration is small.

[0012] In a moving body display system according to a fifth embodiment which may be dependent on the first to fourth embodiments, the predetermined time is set in advance for each moving body.

[0013] According to the display system for a moving body of the present disclosure, the display position of the image can be corrected when the moving body is accelerating or decelerating, thereby making it less likely that the driver will feel uncomfortable visually.

[0014] Fig. 1 is a schematic diagram showing a general configuration of a vehicular display system according to an embodiment. Fig. 2 is a block diagram showing a general configuration of a display control device according to an embodiment. Fig. 3 is a flowchart showing processing by a display control unit according to an embodiment. Fig. 4 is a graph showing time changes in the acceleration value of a vehicle, time changes in the vehicle attitude, time changes in the angular velocity value, correction amounts based on angular velocity, correction amounts based on acceleration, a conventional correction state, and a correction state according to the present disclosure.

[0015] The mobile object display system of the present disclosure will be described in detail below with reference to the drawings, showing a vehicle display system as an example. The mobile object display system can be applied as a display system for mobile objects such as four-wheeled automobiles, two-wheeled automobiles, ships, aircraft, agricultural machinery, and construction machinery.

[0016] 1 is a schematic diagram showing the general configuration of a vehicle display system according to an embodiment. As shown in FIG. 1, a vehicle display system (display system for a moving object) 10 includes a HUD (head-up display) device (display position adjustment means) 100 and a display control device 200.

[0017] The HUD device 100 is installed in an instrument panel 3 of a vehicle (mobile body) 1. The HUD device 100 has a display 101, a plane mirror 102, a concave mirror (display position adjustment means) 103, and a HUD control unit (display position adjustment means) 105, and is housed in a housing 106.

[0018] The display 101 is a device that outputs an image (virtual object) to be visually recognized by the driver 9 as display light L in response to an instruction from the HUD control unit 105. As the display 101, for example, a TFT (Thin Film Transistor) type liquid crystal display or an organic EL (Electroluminescence) type display can be used.

[0019] The plane mirror 102 is a mirror that reflects the display light L (image: virtual object) output from the display device 101 toward the concave mirror 13, and the concave mirror 103 is a mirror that further reflects the display light L reflected by the plane mirror 102 and emits it toward the windshield (display unit) 2. The concave mirror 103 functions as a magnifying mirror and magnifies the image (virtual object) of the display light L output from the display device 101 before irradiating it onto the windshield 2 of the vehicle 1.

[0020] The driver 9 visually recognizes the reflected light of the display light L irradiated onto the windshield 2 as an image (virtual object) V. The image (virtual object) V visually recognized by the driver 9 through the windshield 2 is displayed so as to overlap with the actual scene outside (in front of) the windshield 2.

[0021] In addition, in order to make it easier for the driver 9 to view the image through the windshield 2, it is also possible to install a projector or a screen constituting a display surface on the instrument panel 3 or on the windshield 2.

[0022] The HUD control unit 105 performs processing to output an image (display light L) to the display device 101 based on image information received from a display control unit (control means) 210 of the display control device 200, which will be described later. In addition, the HUD control unit 105 adjusts the drawing position of the image on the display device 101 based on correction information received from the display control unit 210, thereby adjusting the display position of the image (virtual object) projected onto the windshield 2.

[0023] 2 is a block diagram showing a schematic configuration of the display control device 200. The display control device 200 includes a display control unit 210, a memory (storage means) 220, and an I / O interface unit (information acquisition means) 230. The memory 220 stores image data (data such as a sign image or an arrow image) for creating an image (virtual object) V, a program recording the processing details of the display control unit 210, and various data required for processing judgment (threshold data, table data, etc., for example, table data recording adjustment amounts for the display device 101 corresponding to angular velocity information and acceleration information, which will be described later). A typical recording medium such as a magnetic medium, a volatile memory, or a non-volatile memory can be used as the memory 220.

[0024] The I / O interface unit 230 is connected to various devices installed in the vehicle 1, and the display control unit 210 is able to acquire various information from the various devices via the I / O interface unit 230. The I / O interface unit 230 can be connected to, for example, a vehicle ECU (Electronic Control Unit) 311 capable of acquiring acceleration information, speed information, and brake operation information based on the amount of power generated by regenerative braking of the vehicle 1; an external camera unit 312 capable of acquiring information outside the vehicle 1 (for example, image information capturing the situation in front of or behind the vehicle); a vehicle position detection unit 313 consisting of a GPS (Global Positioning System) or the like for detecting the position of the vehicle; an external communication unit 314 connected to an Internet line or the like for sending and receiving various information; an operation detection unit 315 that detects operation information such as the amount of steering of the steering wheel operated by the driver 9 and the amount of depression of the brake pedal and accelerator pedal; an attitude detection unit (attitude detection means) 316 capable of acquiring acceleration information indicating the acceleration of the vehicle 1 and angular velocity information indicating the angular velocity of the vehicle 1; an external sensor unit 317 capable of detecting other vehicles and obstacles present around the vehicle; a brightness detection unit 318 capable of detecting the brightness outside the vehicle; and an information communication terminal 319 consisting of a smartphone, tablet, or the like.

[0025] For the sake of convenience, the I / O interface unit 230 in this embodiment will be described as being the attitude detection unit 316 that can acquire acceleration information and angular velocity information of the vehicle 1.

[0026] The attitude detection unit 316 is a device provided for the purpose of grasping and estimating changes in the attitude of the vehicle 1. An IMU (Inertial Measurement Unit) is generally used as the attitude detection unit 316. The IMU includes an angular velocity (gyro) sensor (deg / s) with three axes (roll axis: axis extending in the front-rear direction of the vehicle 1, pitch axis: axis extending in the left-right direction of the vehicle 1, and yaw axis: axis extending in the up-down direction of the vehicle 1), an acceleration sensor (m / s) with three axes (X axis: axis extending in the front-rear direction of the vehicle 1, Y axis: axis extending in the left-right direction of the vehicle 1, and Z axis: axis extending in the up-down direction of the vehicle 1), and a speed sensor (m / s). 2), etc., are mounted, making it possible to detect three-dimensional inertial motion (translational motion and rotational motion in three orthogonal axial directions). By connecting the attitude detection unit 316 to the I / O interface unit 230, the display control unit 210 is able to acquire acceleration information indicating the acceleration of the vehicle 1 and angular velocity information indicating the angular velocity. The attitude detection unit 316 detects the acceleration and angular velocity at a predetermined period (a predetermined data rate), and outputs the acceleration information and angular velocity information to the I / O interface unit 230.

[0027] The display control unit 210 performs a process of creating an image (virtual object) to be projected onto the windshield 2 and outputting the image to the HUD control unit 105. For example, the display control unit 210 acquires image data of a road sign (such as a maximum speed sign or a no entry sign) from the memory 220 based on an image of the area ahead of the vehicle captured by the external camera unit 312, and creates image information for an appropriate image V to be projected onto the windshield 2. Similarly, the display control unit 210 acquires image data indicating the vehicle speed (image data indicating the driving speed) from the memory 220 based on speed information acquired from the vehicle ECU 311, and creates image information for the image V. The image information created by the display control unit 210 is output in real time to the HUD control unit 105 and projected onto the windshield 2 by the HUD device 100.

[0028] Furthermore, the display control unit 210 creates correction information for adjusting the display position of the image based on the angular velocity information and acceleration information of the attitude detection unit 316 acquired via the I / O interface unit 230, and performs processing to output the correction information to the HUD control unit 105. The HUD control unit 105 adjusts the display position of the image (virtual object) projected onto the windshield 2 by adjusting the positions of the plane mirror 102 and the concave mirror 103 based on the correction information acquired from the display control unit 210.

[0029] It should be noted that information regarding the display position (referred to as the "reference position") at which the image projected onto the windshield 2 and the actual scene are not misaligned relative to each other when the vehicle 1 is level with the road surface is pre-recorded in the memory 220. The display control unit 210 acquires information regarding the reference position from the memory 220, calculates the amount of deviation of the image from the reference position based on changes in the attitude of the vehicle 1, and corrects this amount of deviation, thereby performing a correction process for the display position of the image (virtual object).

[0030] Furthermore, based on the angular velocity information acquired from the attitude detection unit 316, the display control unit 210 calculates a pitch angle indicating the angle of inclination of the front or rear portion of the vehicle 1 relative to the vehicle 1 in a horizontal state, a roll angle indicating the angle of inclination of the left or right portion of the vehicle 1 relative to the vehicle 1 in a horizontal state, and a yaw angle indicating the turning angle of the vehicle 1. Methods for calculating the pitch angle, roll angle, and yaw angle based on angular velocity information are well known, and various methods can be used. For example, a calculation method using an integral calculation of angular velocity or a calculation method using a Kalman filter is known. It is also possible to calculate the pitch angle, roll angle, and yaw angle based on the acceleration information acquired from the attitude detection unit 316. Since these methods are also well known, detailed description thereof will be omitted here. Note that in some embodiments, calculation of the roll angle and / or yaw angle may be omitted.

[0031] Next, a process performed by the display control unit 210 to correct the display position of the image projected onto the windshield 2 based on angular velocity information and acceleration information will be described. Fig. 3 is a flowchart showing the process performed by the display control unit 210. Fig. 4 is a graph showing the change over time in the value of vehicle acceleration, the change over time in the vehicle attitude, the change over time in the value of angular velocity, the correction amount based on angular velocity, the correction amount based on acceleration, a conventional correction state, and a correction state according to the present disclosure.

[0032] First, the display control unit 210 acquires acceleration information and angular velocity information of the vehicle 1 from the attitude detection unit 316 via the interface unit 230 (S.01). Then, the display control unit 210 records the acquired acceleration information and angular velocity information in the memory 220 (S.02). Note that the display control unit 210 acquires acceleration information and angular velocity information from the attitude detection unit 316 at predetermined intervals as described above, and repeatedly executes the process shown in Fig. 3 as described below. Therefore, a plurality of pieces of acceleration information and angular velocity information acquired at different times (intervals) are recorded in chronological order in the memory 220.

[0033] Next, the display control unit 210 calculates the amount of attitude fluctuation of the vehicle 1 based on the acquired angular velocity information (S.03). The amount of attitude fluctuation is information that numerically indicates how much the vehicle 1 is tilted relative to the road surface from a horizontal state while the vehicle 1 is traveling. As an example, the display control unit 210 of the present disclosure calculates the amount of attitude fluctuation as the pitch angle in the fore-and-aft direction of the vehicle 1.

[0034] Next, the display control unit 210 performs processing to correct the display position of the image (virtual object) based on the angular velocity information in order to move the display position of the image in the vertical direction in accordance with an increase or decrease in the angular velocity. The correction amount set by the display control unit 210 is called the angular velocity correction amount because it is a correction amount set in accordance with the angular velocity. The angular velocity correction amount indicates the amount of movement of the image to be moved in accordance with the angular velocity, expressed by, for example, the amount of adjustment of the drawing position of the image on the display device 101.

[0035] When the front portion of the vehicle 1 is not tilted (when the pitch angle is 0 degrees), the image is projected (displayed) at a reference position relative to the windshield 2. When the pitch angle is detected from the angular velocity information (when the pitch angle is not 0 degrees), the display control unit 210 determines how much the display position of the image has deviated (shifted) from the reference position due to the pitch angle, and sets an adjustment amount (correction amount) for adjusting the drawing position of the image on the display unit 101 according to the angular velocity. The display unit 101 adjustment amount (correction amount) set according to the angular velocity is recorded in advance in the memory 220 as table data or the like. The display control unit 210 sets the angular velocity correction amount by calculating the adjustment amount (correction amount) corresponding to the acquired angular velocity information based on the table data. (S.04)

[0036] Next, the display control unit 210 performs a process to calculate a "delay time (predetermined time)" for executing the "acceleration-based correction process" described below (S.05). First, consider a situation in which the attitude of the vehicle 1 changes in response to acceleration information. The following states (1) to (4) can be assumed as situations in which the attitude of the vehicle 1 changes in response to acceleration information. (1) A state in which the driver 9 depresses the accelerator pedal while the vehicle 1 is stopped or traveling at a constant speed, causing the vehicle 1 to accelerate and the acceleration value to begin to increase (a state in which the acceleration value increases steadily to the right: time T1 shown in "1. Change in acceleration value over time" in FIG. 4). (2) A state in which the driver 9 releases the accelerator pedal while the vehicle 1 is maintaining a constant acceleration, causing the acceleration of the vehicle 1 to begin to decrease and the speed of the vehicle 1 to become constant (a state in which the acceleration value decreases steadily to the right: time T2 shown in "1. Change in acceleration value over time" in FIG. 4). (3) When the vehicle 1 is traveling at a constant speed, the driver 9 depresses the brake pedal, causing the vehicle 1 to decelerate and the acceleration value to begin to decrease (the acceleration value decreases downward to the right: time T3 shown in "1. Change in acceleration value over time" in Figure 4). (4) When the vehicle 1 is maintaining a constant acceleration, the driver 9 releases the brake pedal, causing the acceleration of the vehicle 1 to begin to increase and the speed of the vehicle 1 to become constant (the acceleration value increases upward to the right: time T4 shown in "1. Change in acceleration value over time" in Figure 4).

[0037] The above-described states (1) to (4) are states in which the attitude of the vehicle 1 changes, and therefore the angular velocity values ​​detected by the attitude detection unit 316 also increase or decrease (see the angular velocity values ​​at times T1 to T4 in "3. Change in angular velocity values ​​over time" in FIG. 4). The display control unit 210 detects each of the states (1) to (4) and determines each of the times T1 to T4 shown in FIG. 4 as a delay time (predetermined time).

[0038] 4 shows, from top to bottom, the above-mentioned "1. Change in acceleration value over time," "2. Change in vehicle attitude over time," the above-mentioned "3. Change in angular velocity value over time," and "4. Correction amount based on angular velocity." In state (1), while the driver 9 is depressing the accelerator pedal to increase acceleration (T1 in FIG. 4), the acceleration value increases steadily to the right in "1. Change in acceleration value over time," and the pitch angle indicating "2. Change in vehicle attitude over time" also increases over time. Similarly, while the driver 9 is depressing the accelerator pedal to increase acceleration (T1 in FIG. 4), the angular velocity of "3. Change in angular velocity value over time," which is calculated based on the angular velocity information, also increases steadily to the right.

[0039] At this time, the pitch angle of the vehicle 1 increases and the front part of the vehicle 1 tilts upward, so the display control unit 210 performs a correction to move (shift) the display position of the image downward in accordance with the value of the angular velocity indicated by "3. Change in the value of the angular velocity over time." "4. Correction amount based on the angular velocity" in Fig. 4 illustrates the angular velocity correction amount for correcting (moving (shifting)) the display position of the image based on the value of the angular velocity.

[0040] After this, by the driver 9 maintaining a constant amount of depression of the accelerator pedal, the acceleration value in "1. Time change in acceleration value" becomes a constant value, and the pitch angle indicating "2. Time change in vehicle attitude" also maintains the same angle. On the other hand, by maintaining a constant amount of depression of the accelerator pedal, the angular velocity in "3. Time change in angular velocity value" decreases downward to the right and becomes 0 (zero) (converges to 0).

[0041] The display control unit 210 detects the delay time (time T1) as the time it takes for the acceleration value shown in "1. Change in acceleration value over time" to increase steadily from a fixed value and to return to a fixed value again. Specifically, the display control unit 210 calculates the delay time T1 by measuring the time it takes for the acceleration value to increase from a fixed value over time and to return to a fixed value again, based on the acceleration information acquired in the processing of S.01.

[0042] Alternatively, the delay time T1 may be calculated by measuring the time during which the acceleration value shown in "1. Change in acceleration value over time" continues to increase over time, and further measuring the time during which the angular velocity value shown in "3. Change in angular velocity value over time" increases over time from a constant value until just before it starts to decrease.

[0043] In addition, the delay time T1 may be obtained by measuring the time it takes for the pitch angle value, which indicates "2. Change in vehicle attitude over time," to increase from a constant value over time and then return to a constant value again.

[0044] Furthermore, the delay time T1 may be calculated by measuring the time during which the value of the pitch angle indicating "2. Change in vehicle attitude over time" continues to increase over time, and the time until the value of the angular velocity indicated in "3. Change in angular velocity value over time" increases over time from a constant value and then immediately begins to decrease.

[0045] The display control unit 210 performs processing to calculate the delay time T1 in state (1) using one of the methods described above. Similarly, the display control unit 210 performs processing to calculate delay times T2 to T4 in states (2) to (4) in addition to state (1). Note that if the acceleration value remains constant or if the pitch angle, which indicates a change in vehicle attitude over time, remains constant, the increase in acceleration or pitch angle cannot be detected or measured, and therefore the delay time cannot be calculated. In such cases where the delay time cannot be calculated, the display control unit 210 sets Null (empty information) as the delay time.

[0046] The display control unit 210 records the delay time calculated in S.05 in the memory 220 (S.06). As described above, because the display control unit 210 repeatedly executes the process shown in FIG. 3, the memory 220 records not one delay time but multiple delay times in chronological order. Therefore, even if delay information set to "Null" continues chronologically, multiple delay information items are recorded chronologically. Therefore, it is possible to detect delay information recorded before the current time that contains information other than "Null" (T1 to T4).

[0047] The display control unit 210 determines whether the delay time calculated at the current time is "any of times T1 to T4" (whether the delay time is other than null) (S.07). If the delay time is "any of times T1 to T4" (if the delay time is not null, Yes in S.07), the display control unit 210 acquires acceleration information recorded the delay time (T1 to T4) before the current time from the acceleration information recorded in the memory 220 (see the processing in S.02) (S.08). As described above, since multiple pieces of acceleration information are recorded in chronological order at predetermined cycles in the memory 220, the display control unit 210 extracts / acquires acceleration information recorded a number of times before (acceleration information acquired a predetermined time ago) calculated by dividing the delay time by one cycle. The display control unit 210 sets an acceleration correction amount for correcting (moving (shifting)) the display position of the image based on the acceleration value of the acquired acceleration information (S.09). Specifically, the display control unit 210 sets the correction amount so that the display position of the image moves (shifts) downward when the acceleration value is positive, and sets the correction amount so that the display position of the image moves (shifts) upward when the acceleration value is negative.

[0048] Here, the correction amount set by the display control unit 210 is referred to as an acceleration correction amount because it is a correction amount set based on the acceleration value. The acceleration correction amount is a correction amount that indicates the amount of movement of an image to be moved according to the acceleration value, by, for example, the adjustment amount of the image drawing position on the display unit 101. The display control unit 210 determines how much the image display position will move (shift) from a reference position based on the attitude state (pitch angle) of the vehicle 1, and sets the adjustment amount (correction amount) for adjusting the image drawing position on the display unit 101. The adjustment amount (correction amount) of the display unit 101 that is set according to acceleration is recorded in advance in the memory 220 as table data or the like. The display control unit 210 sets the acceleration correction amount by calculating the adjustment amount (correction amount) corresponding to the acquired acceleration information based on the table data.

[0049] On the other hand, if the delay time is not "one of times T1 to T4" (if Null is set for the delay time, No in S.07), the display control unit 210 reads out from the multiple delay information stored in the memory 220 delay information other than Null that was recorded before the current time and that was recorded closest to the current time (recorded in order of closest to the current time) (S.10).The display control unit 210 then obtains from the memory 220 acceleration information that was recorded before the current time by the delay time of the read delay information (S.11).The display control unit 210 sets an acceleration correction amount for moving the display position of the image based on the acceleration value of the obtained acceleration information (S.12).

[0050] In FIG. 4, the change in the acceleration correction amount over time is shown as "5. Correction amount based on acceleration." The acceleration correction amount corresponds to the increase or decrease in acceleration shown in "1. Change in acceleration value over time," and is decreased when acceleration increases, and increased when acceleration decreases, thereby correcting the display position of the image. Here, as shown in FIG. 4, the acceleration correction amount is configured to delay the correction based on the acceleration value by delay times T1 to T4. In this way, by executing the "acceleration-based correction process" after the delay times T1 to T4 have elapsed (delaying the execution timing of the "acceleration-based correction process" by the delay times), the acceleration-based correction process can be started at the timing when the delay time has elapsed after the correction process based on angular velocity has been performed.

[0051] Therefore, even if the acceleration of the angular velocity information acquired by the attitude detection unit 316 converges to 0 over time, the "5. Correction amount based on acceleration" can be increased to compensate for the decrease in the "4. Correction amount based on angular velocity". Therefore, even if the correction of the image display position based on the "4. Correction amount based on angular velocity" is completed when the vehicle attitude is inclined rather than horizontal with respect to the road surface, the correction process based on the "5. Correction amount based on acceleration" can be performed. This makes it possible to prevent the image from moving significantly upward or downward relative to the reference position, and to suppress the image display from causing a visual discomfort to the driver 9.

[0052] "6. Conventional correction state" shown in Fig. 4 is a graph showing the amount of deviation of the display position of an image from the reference position when the display position of an image is corrected only by correction processing based on angular velocity (using only angular velocity correction information). Also, "7. Correction state of the present disclosure" shown in Fig. 4 is a graph showing the amount of deviation of the display position of an image from the reference position when correction is performed not only by correction processing based on angular velocity (only angular velocity correction information) but also by correction processing based on acceleration (using acceleration correction information).

[0053] As described above, in the conventional correction state, when the value of the angular velocity indicated in "3. Time change of the angular velocity value" converges to 0 (zero), no correction is made to the display position of the image even if the vehicle attitude is not horizontal to the road surface (the pitch angle is not 0). Therefore, during time TA in "6. Conventional correction state," the image is displayed above the actual scene, causing the driver 9 to see the image as if it is floating. On the other hand, after that, when "4. Correction amount based on angular velocity" begins to converge to 0 (time TB), the image appears to the driver 9 to have moved.

[0054] Similarly, when the driver 9 operates the brake pedal and the acceleration becomes a constant value (time TC), the image is displayed below the actual scene, and the image appears to the driver 9 to be sunken. Furthermore, after that, when "4. Correction amount based on angular velocity" begins to converge to 0 (time TD), the image appears to the driver 9 to be moving.

[0055] As described above, in the conventional correction state, the display position of the image changes relatively significantly depending on the posture of the vehicle, which causes a visual discomfort to the driver 9. On the other hand, in "7. Correction state of the present disclosure" shown in Fig. 4, correction based on the angular velocity is performed, and then correction based on the acceleration value is performed at a timing when a delay time has elapsed, so it is possible to maintain the display position of the image in a stable state regardless of the posture of the vehicle 1 (maintaining the deviation of the display position of the image from the reference position at 0 (zero)).

[0056] After setting the acceleration correction amount in the process of S.09 or S.12 of Fig. 3, the display control unit 210 combines the information on the acceleration correction amount set in S.09 or S.12 (acceleration correction information) with the information on the angular velocity correction amount set in S.04 (angular velocity correction information) to set the correction information (S.13). The display control unit 210 then outputs the set correction information to the HUD control unit 105 (S.14), thereby ending the process shown in Fig. 4. The HUD control unit 105 adjusts the display position of the image projected on the windshield 2 by adjusting the drawing position of the image on the display 101 based on the correction information acquired from the display control unit 210.

[0057] After the process shown in Fig. 4 is completed, the display control unit 210 repeatedly executes the process shown in Fig. 4. By repeatedly executing the process shown in Fig. 4, the display control unit 210 can quickly correct the display position of the image in accordance with changes in the attitude of the vehicle 1, and it is possible to reduce the visual discomfort felt by the driver 9.

[0058] Although the mobile object display system of the present disclosure has been described in detail above using the drawings, the mobile object display system of the present disclosure is not limited to the content described in the embodiment. For example, the display control unit 210 of the present disclosure is configured to perform correction processing based on angular velocity without causing a delay, while performing correction processing based on acceleration after a delay time has elapsed. However, the execution timing of correction processing based on angular velocity is not limited to this configuration.

[0059] In the moving body display system of the present disclosure, correction based on acceleration may be started immediately after correction based on angular velocity (more specifically, at the timing when the angular velocity value changes from increasing to decelerating). For this reason, a delay or the like (for convenience, these times will be referred to as a "first time") may occur between the time when the control means (display control unit 210) acquires angular velocity information and the time when the control means sets correction information using the angular velocity information and outputs the correction information to the display position adjustment means (HUD control unit 105, display 101) (or the time when the correction process for the display position of the image is performed accordingly).

[0060] However, because a delay time must be ensured between the start of correction processing based on correction information using angular velocity and the start of correction processing based on correction information using acceleration, the first time period is shorter than the time period from when the control means (display control unit 210) acquires acceleration information to when the control means sets correction information using the acceleration information and outputs the correction information to the display position adjustment means (HUD control unit 105, display 101) (or the time period from when the control means acquires acceleration information to when the correction processing for the image display position is performed) (for convenience, these times will be referred to as the “second time period”). By making the first time period as short as possible, it is possible to quickly correct the image position display in response to changes in the vehicle attitude and to alleviate any visual discomfort caused by the image display state.

[0061] Furthermore, in the vehicular display system 10 of the present disclosure, as an example, the delay time (predetermined time) until the acceleration-based correction process is initiated is calculated based on the time it takes for the acceleration to increase or decrease from a constant value and then settle back to a constant value. Therefore, the delay time is shorter when the acceleration increase or decrease is small, and longer when the acceleration increase or decrease is large. Thus, the delay time varies depending on the increase or decrease in the acceleration, and also on the time it takes for the acceleration to increase or decrease from a predetermined value to another value (e.g., the slope of the acceleration increase or decrease). Therefore, the display control unit 210 of the present disclosure can vary the delay time depending on the increase or decrease in the acceleration or the state of change in the acceleration increase or decrease, thereby flexibly adjusting the time until the image display position is corrected.

[0062] Furthermore, in the vehicular display system 10 of the present disclosure, the delay time (predetermined time) is determined by the time it takes for the acceleration to increase or decrease from a certain value to reach a certain value, or by the time it takes for the pitch angle of the vehicle 1 to increase from a certain value to reach a certain value, etc. However, the delay time is not limited to being set or determined by such a method.

[0063] The change in vehicle posture caused by the operation of the accelerator pedal or brake pedal has unique characteristics for each vehicle. For example, the change in vehicle posture varies depending on the characteristics of the vehicle's suspension, vehicle weight, etc. On the other hand, it is known that a certain pedal operation causes a certain change in posture for vehicles with similar weights and suspension structures, and it is possible to set and determine the delay time (predetermined time) for each vehicle in advance based on experimental values. For this reason, it is possible to investigate the change in posture caused by pedal operation for each vehicle in advance through experiments, etc., and determine the delay time (predetermined time) for a certain operation in advance for each vehicle.

[0064] Specifically, the delay times in the states (1) to (4) described in this disclosure can be determined experimentally for each vehicle and recorded in advance in memory 220, so that the display control unit 210 can read the delay times from memory 220 for each of the states (1) to (4) and perform a correction process for the image display position as shown in Figure 4.

[0065] Furthermore, in the vehicular display system 10 of the present disclosure, the delay time is determined based on the acceleration information detected by the orientation detection unit 316, but the acceleration information used to determine the delay time is not limited to that detected by the orientation detection unit 316. For example, acceleration information determined by the vehicle ECU 311 can also be used.

[0066] REFERENCE SIGNS LIST 1 ... Vehicle (mobile body) 2 ... Windshield (display unit) 3 ... Instrument panel 9 ... Driver 10 ... Vehicle display system (display system for mobile body) 100 ... HUD device (display position adjustment means) 101 ... (HUD device) display (display position adjustment means) 102 ... (HUD device) plane mirror 103 ... (HUD device) concave mirror 105 ... (HUD device) HUD control unit (display position adjustment means) 106 ... (HUD device) housing 200 ... Display control device 210 ... (display control device) display control unit (control means) 220 ... (display control device) memory (recording means) 230 ... (display control device) I / O interface unit (information acquisition means) 311 ... Vehicle ECU 312 ... External camera unit 313 ... Vehicle position detection unit 314 ... External communication unit 315 ... Operation detection unit 316 ... Attitude detection unit (attitude detection means) 317 ... Vehicle exterior sensor unit 318 ... Brightness detection unit 319 ... Information communication terminal T1 to T4 ... Delay time (predetermined time)

Claims

1. A display system for a moving body that displays an image on a display unit installed in the direction of travel of a moving body so as to be superimposed on an actual scene in the direction of travel of the moving body, comprising: information acquisition means for acquiring angular velocity information consisting of information indicating the angular velocity of the moving body and acceleration information consisting of information indicating the acceleration of the moving body from an attitude detection means installed on the moving body; control means for setting correction information for correcting the display position of an image to be displayed on the display unit based on the angular velocity of the angular velocity information acquired by the information acquisition means and the acceleration of the acceleration information acquired a predetermined time before the time when the angular velocity information was acquired by the information acquisition means; and display position adjustment means for adjusting the display position of the image displayed on the display unit based on the correction information set by the control means.

2. A moving body display system as described in claim 1, further comprising a recording means for recording multiple pieces of the acceleration information acquired by the information acquisition means in chronological order, and wherein the control means extracts from the recording means acceleration information acquired a predetermined time before the time when the angular velocity information was acquired by the information acquisition means, and sets the correction information based on the acceleration of the extracted acceleration information and the angular velocity of the angular velocity information acquired by the information acquisition means.

3. A display system for a moving body as described in claim 1, characterized in that the time from when the angular velocity information is acquired by the information acquisition means to when the control means sets the correction information using the angular velocity of the angular velocity information and outputs it to the display position adjustment means is shorter than the time from when the acceleration information is acquired by the information acquisition means to when the control means sets the correction information using the acceleration of the acceleration information and outputs it to the display position adjustment means.

4. A moving object display system according to claim 1, characterized in that the predetermined time varies so that it is longer when the increase in acceleration is large and shorter when the increase in acceleration is small.

5. A display system for a moving body as claimed in any one of claims 1 to 4, characterized in that the predetermined time is set in advance for each moving body.

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