Display control device, display device, and display control method

Abstract

To appropriately correct bias errors included in vehicle vibration information without causing the sense of discomfort to occupants of the vehicle.SOLUTION: A display control device 36 comprises: a vehicle vibration information acquisition unit 40; a vehicle state determination unit 41; a bias error correction value acquisition unit 42 that acquires a bias error correction value for correcting a bias error during a vehicle stop period; a bias error correction unit 43; a vehicle posture variation amount detection unit 44; and a display correction unit 45 that changes at least one of the position or size of an image. The bias error correction unit 43 performs at least one of first correction processing in which the previous bias error correction value is gradually changed over time and transitioned to the updated bias error correction value over a period of the change, and second correction processing in which a transition operation of transitioning the previous bias error correction value to the updated bias error correction value is not performed during the vehicle stop period but performed during a vehicle travel period.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a display control device, a display device, a display control method, and the like. [Background technology]

[0002] A configuration for correcting the display position of an image based on a change in the vehicle's attitude is described, for example, in Patent Document 1. In Patent Document 1, the angular velocity detected by a gyro sensor is integrated to calculate the amount of change in the vehicle's attitude, and the display position of the image is corrected so that the characteristic part of the image is positioned within the display area even when a large change in attitude occurs.

[0003] Furthermore, sensors such as gyro sensors mounted on vehicles may produce non-zero output values ​​even when the vehicle is stopped and the sensor input (in other words, vibrations due to pitching or rolling of the vehicle) is substantially zero, which is called bias error. The bias error of the sensor may be a cause of errors in measuring the fluctuations in the vehicle's attitude. Correction of this bias error is described, for example, in Patent Document 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 208883 [Patent Document 2] JP 2003-065767 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present inventors have conducted studies and have found the following problems. (1) While the vehicle is running, the bias error value fluctuates depending on the temperature environment and the type and degree of vibration of the vehicle. Therefore, even if the bias error is corrected once, if the same bias error correction value is continued to be used, it is not possible to deal with the above-mentioned bias error fluctuations. (2) When bias error correction is performed while the vehicle is moving (including not only the period when the vehicle is actually moving but also the period when the vehicle is stopped), the display position of the image may change due to the bias error correction, and this change in display position may give an uncomfortable feeling to the occupants of the vehicle (the driver and passengers). (3) In particular, if a change in the display position of an image occurs due to bias error correction while the vehicle is stopped (for example, if an image is superimposed on an object and the position of the superimposed image changes even while the vehicle is stopped), this is likely to be noticeable to passengers and cause discomfort. In other words, when the vehicle is stopped, the occupants do not need to gaze intently at the road ahead in order to drive safely, and can look ahead with ease. Also, since there is very little vibration of the vehicle while it is stopped, the occupants are more likely to see sudden changes in the image position, and therefore are more likely to feel uncomfortable.

[0006] Such a problem was identified by the inventors' investigations. However, the above-mentioned Patent Documents 1 and 2 make no mention of such a problem, and also make no mention of a solution to the problem.

[0007] An object of the present invention is to appropriately correct bias errors contained in vehicle vibration information without causing discomfort to vehicle occupants.

[0008] Other objects of the present invention will become apparent to those skilled in the art by referring to the following exemplary aspects and best modes, as well as the accompanying drawings. [Means for solving the problem]

[0009] In order to facilitate an understanding of the outline of the present invention, embodiments according to the present invention will be exemplified below.

[0010] In a first aspect, a display control device is a display control device that is mounted on a vehicle and controls image display of a display device that allows an image to be viewed by a passenger aboard the vehicle, and includes a vehicle vibration information acquisition unit that acquires vibration information of the vehicle, a vehicle state determination unit that determines whether the vehicle is moving or stopped, a bias error correction value acquisition unit that acquires a bias error correction value that corrects a bias error included in the acquired vibration information during a period when the vehicle is stopped, a bias error correction unit that corrects the vibration information based on the acquired bias error correction value, a vehicle attitude fluctuation amount detection unit that detects an amount of fluctuation in the attitude of the vehicle based on the corrected vibration information, and a vehicle attitude fluctuation amount detection unit that detects an amount of fluctuation in the attitude of the vehicle based on the detected amount of fluctuation in the attitude of the vehicle. and a display correction unit that changes at least one of a position and a size of an image, wherein the bias error correction unit performs at least one of a first correction process in which, when the latest bias error correction value acquired by the bias error correction value acquisition unit is an updated bias error correction value and the bias error correction value before the update is performed is a previous bias error correction value, the bias error correction unit gradually changes the previous bias error correction value over time and transitions it to the updated bias error correction value after a period of change, and a second correction process in which a transition operation of transitioning the previous bias error correction value to the updated bias error correction value is not performed while the vehicle is stopped, but is performed while the vehicle is traveling.

[0011] In the first aspect, first, during a stop period of the vehicle, the bias error correction value acquisition unit acquires (in other words, updates) the bias error correction value. For example, when the vehicle is heading to a destination, the vehicle repeatedly travels and stops, and the bias error correction value is updated as needed, for example, every time the vehicle stops, or during a stop period that coincides with the update timing of the bias error correction value (for example, set in advance to a predetermined cycle) among multiple stop periods. The bias error of a gyro sensor or the like changes depending on the temperature environment while the vehicle is traveling, but according to this aspect, the bias error correction value is updated as needed using the stop periods, making it possible to respond to changes in the bias error over time.

[0012] Next, based on this updated bias error correction value, the bias error contained in the vibration information (basically the output value of the sensor, specifically, the angular velocity associated with pitching or rolling, etc.) is corrected while the vehicle is running (a broad concept including the actual running state of the vehicle and the stopped state).

[0013] However, if the bias error correction is carried out unconditionally, the display position of the image will change every time the bias error is corrected, and this change may be noticeable to the passengers, causing them to feel uncomfortable.

[0014] In this embodiment, as a countermeasure to this, at least one of the first and second correction processes is performed, and a predetermined condition is imposed on the correction of the bias error.

[0015] In the first correction process, when the latest acquired bias error correction value is referred to as an “updated bias error correction value” and the bias error correction value before the update is referred to as a “previous bias error correction value”, the “previous bias error correction value” is not abruptly changed to become the “updated bias error correction value”, but the “previous bias error correction value” is gradually changed over time and transitioned to the “updated bias error correction value” after a period of change.

[0016] According to the first correction process, the bias error correction value changes gradually over time, and the corresponding movement in the image position is also gradual and does not cause abrupt (step-like) movement. This makes it less noticeable to vehicle occupants, and can reduce the discomfort felt by the occupants.

[0017] The second correction process imposes a condition on the timing of bias error correction, and is a correction process in which the bias error correction value transition operation is not performed while the vehicle is stopped, but is performed while the vehicle is traveling.

[0018] Unlike the first correction process, this second correction process does not gradually change the bias error correction value over time. However, the bias error correction process is performed during driving periods, avoiding stopped periods when changes in image position are likely to be noticeable to passengers, thereby reducing the discomfort felt by passengers.

[0019] In this aspect, three embodiments can be assumed: performing only the first correction process, performing both the first and second correction processes, or performing only the second correction process. In any of the embodiments, the effect is obtained that the change in image position caused by the change in the bias error correction value is less noticeable to the passenger, and the occurrence of discomfort is suppressed.

[0020] In a second aspect dependent on the first aspect, the bias error correction value acquisition unit may calculate a moving average of output values ​​of a sensor that detects vibration information of the vehicle each time a timing for updating the bias error correction value arrives during a period when the vehicle is stopped, and determine the bias error correction value based on the calculated moving average value.

[0021] In the second mode, while the vehicle is stopped, a moving average of the output values ​​of the sensor is calculated each time the timing for updating the bias error correction value arrives, and the bias error correction value is determined (updated) based on the moving average value.

[0022] During the period when the vehicle is stopped (including the period when the vehicle can be considered to be substantially stopped), the sensor input (in other words, vibration due to pitching or rolling of the vehicle) is considered to be substantially zero (in other words, close to zero). In this case, if a non-zero output value is generated from the sensor, the output value indicates an error in the sensor input / output. However, the error varies over time.

[0023] Taking this into consideration, in this embodiment, a moving average of the output value (e.g., angular velocity value) of the sensor is calculated. A "moving average" is an average value of time-series data in a predetermined interval. When multiple predetermined intervals are set, the average of data obtained in each interval may be calculated and used as the moving average. It is easy to obtain a moving average, it is possible to perform a high-speed calculation, and the burden on the processor, etc. is small.

[0024] The moving average value of the sensor output value (e.g., angular velocity value) can also be called the bias error of the sensor. If there is a difference between the previous bias error and the latest bias error (updated bias error), the sensor output value (e.g., angular velocity value) is corrected using the latest bias error. This improves, for example, the measurement accuracy of the vehicle attitude fluctuation amount.

[0025] In a third aspect dependent on the first or second aspect, when the bias error correction unit performs the first correction process, the first correction process may be performed during a period including a stop period during which the bias error correction value was acquired by the bias error correction value acquisition unit.

[0026] In the third aspect, when the bias error correction value is acquired (updated) during a vehicle stop period, the first correction process is performed during a period including the vehicle stop period. As described above, when the bias error correction is performed during a vehicle stop period, the associated movement of the image position is likely to be noticeable to the vehicle occupants.

[0027] However, by performing the first correction process (a correction process that gradually changes the bias error correction value over time), it is possible to prevent the movement of the image position from being noticed by the passenger. Taking advantage of this advantage, in this embodiment, after the bias error correction value is acquired (updated), the bias error correction is performed during the period that includes the same stopping period. Therefore, the bias error correction is performed during the period including the stopped period. Here, the expression "a period including a stopped period" indicates that "the first correction process is started during that stopped period, but the first correction process may not be completed at the time driving starts, in which case the first correction process may be continued until the period in which the first correction process is completed, even after driving starts." As a result, when the vehicle transitions from a stopped state to a moving state, the image is displayed in the correct position from the beginning of the moving state without being affected by bias error, allowing the passengers to view the image without any discomfort.

[0028] In a fourth aspect dependent on the first or second aspect, the bias error correction unit uses the first and second correction processes in combination, whereby the first correction process may not be performed while the vehicle is stopped, but may be performed while the vehicle is traveling.

[0029] In the fourth aspect, the first and second correction processes are used in combination. In other words, the first correction process, which gradually changes the bias error correction value over time, is not performed while the vehicle is stopped, but is performed while the vehicle is traveling. By avoiding the stopped period when the passenger has relatively more time (and the vehicle vibration is extremely small) and performing the first correction process only while the vehicle is moving, the possibility that the passenger will perceive the change in the image position caused by the bias error correction is further reduced. Therefore, the possibility that the passenger will feel uncomfortable can be further reduced.

[0030] In a fifth aspect dependent on the first or second aspect, when the bias error correction value acquisition unit performs the second correction process, the bias error correction value acquisition unit may wait for the vehicle to transition to a traveling state while acquiring the bias error correction value every time an update timing for the bias error correction value arrives during a stopped period of the vehicle, and when the vehicle transitions to a traveling state, transition the previous bias error correction value to the latest updated bias error correction value.

[0031] In the fifth aspect, when the second correction process (a correction process that performs bias error correction only while the vehicle is traveling) is performed, an operation is performed to wait for the vehicle to move to a traveling state while the vehicle is stopped, while acquiring a bias error correction value every time the timing for updating the bias error correction value arrives. Then, when the vehicle moves, the previous bias error correction value is changed to the latest updated bias error correction value, thereby performing bias error correction.

[0032] According to this aspect, accurate bias error correction can be performed based on the latest bias error correction value. In addition, by avoiding the stopped period when the passenger has a relatively relaxed time (and the vehicle vibration is very small) and performing the second correction process only while the vehicle is moving, the possibility that the passenger will notice the change in the image position caused by the bias error correction is reduced. Therefore, the possibility that the passenger will feel uncomfortable can be reduced.

[0033] In a sixth aspect dependent on the first to fifth aspects, the vibration information of the vehicle may be angular velocity or acceleration information in at least one of pitching and rolling of the vehicle.

[0034] According to the sixth aspect, the angular velocity or acceleration, which is vibration information, can be accurately corrected using the latest bias error correction value, and thus it is possible to detect (measure) posture fluctuations such as pitching and rolling with higher accuracy.

[0035] In a seventh aspect, a display device includes the display control device according to any one of the first to sixth aspects, and a display unit in which image display is controlled by the display control device.

[0036] According to the seventh aspect, it is possible to realize a high-performance display device capable of appropriately correcting bias error contained in vibration information of a vehicle without giving a sense of discomfort to passengers of the vehicle.

[0037] In an eighth aspect dependent on the seventh aspect, the display device may be a head-up display device further having an optical system that projects display light of an image displayed on the display unit onto a projection member provided in the vehicle, and having the function of allowing the occupant to view a virtual image.

[0038] According to the eighth aspect, it is possible to realize a high-performance head-up display (HUD) device capable of appropriately correcting bias error contained in vibration information of a vehicle without causing discomfort to vehicle occupants.

[0039] In a ninth aspect, a display control method is a display control method for a display device mounted on a vehicle, and includes the steps of: acquiring a bias error correction value for correcting a bias error included in vibration information of the vehicle during a stopped period of the vehicle; correcting the vibration information based on the bias error correction value; detecting an amount of variation in an attitude of the vehicle based on the corrected vibration information; and changing at least one of a position and a size of the image to correspond to the detected amount of variation in the attitude of the vehicle. In a case where a latest bias error correction value acquired by the step of acquiring the bias error correction value is an updated bias error correction value and a bias error correction value before the update is performed is a previous bias error correction value, in the step of correcting the vibration information, at least one of a first correction process in which the previous bias error correction value is gradually changed over time and transitioned to the updated bias error correction value after a period of change, and a transition operation in which the previous bias error correction value is transitioned to the updated bias error correction value are not performed during a stopped period of the vehicle, but a second correction process is performed during a traveling period of the vehicle.

[0040] According to the ninth aspect, it is possible to realize a display control method capable of appropriately correcting bias error contained in vibration information of a vehicle without giving a sense of discomfort to passengers of the vehicle.

[0041] Those skilled in the art will easily understand that the exemplified embodiments according to the present invention can be further modified without departing from the spirit of the present invention. [Brief description of the drawings]

[0042] [Figure 1] FIG. 1 is a diagram showing a configuration example of a display control device, a configuration example of a display device (a head-up display (HUD device)) using the display control device, and a configuration example of a display system. [Diagram 2] FIG. 2 is a diagram showing problems associated with bias error correction that were considered by the present inventor prior to the present invention. [Diagram 3] FIG. 3 is a flowchart showing a main operation procedure of the display control device in the first embodiment. [Figure 4] FIG. 4 is a waveform diagram showing a main operation of the display control device in the first embodiment. [Diagram 5] FIG. 5 is a flowchart showing a main operation procedure of the display control device in the second embodiment. [Figure 6] FIG. 6 is a waveform diagram showing the main operations of the display control device in the second embodiment. [Figure 7] FIG. 7 is a flowchart showing a main operation procedure of the display control device in the third embodiment. [Figure 8] FIG. 8 is a waveform diagram showing the main operations of the display control device in the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] The best mode described below is used to easily understand the present invention. Therefore, those skilled in the art should be aware that the present invention is not unduly limited by the mode described below.

[0044] In the following, a bias error correction process will be described in a case where the image position and the like are corrected in response to pitching and rolling of the vehicle, but this is merely an example and the present invention is not limited to this.

[0045] Vehicle pitching is a state in which the vehicle rotates back and forth around its left-right axis (an axis that passes through the center of the vehicle (e.g., the center of gravity) and extends in the left-right direction of the vehicle), causing a so-called vertical sway, and the vehicle's posture becomes tilted forward or backward.

[0046] Vehicle rolling is a state in which the vehicle rotates left and right around the front-to-rear axis (an axis that passes through the center of the vehicle (e.g., the center of gravity) and extends in the fore-and-aft direction of the vehicle), causing a so-called lateral sway, and the vehicle's posture becomes tilted to the left or right.

[0047] In FIG. 1, the X direction indicates the left-right direction of the vehicle, the Y direction indicates the height direction of the vehicle, and the Z direction indicates the front-rear direction (front or rear) of the vehicle.

[0048] (First embodiment) Please refer to Fig. 1. Fig. 1 is a diagram showing an example of the configuration of a display control device, a display device (head-up display (HUD device)) using the display control device, and a display system.

[0049] The HUD device 100 projects (projects) display light of an image onto the windshield 2 of the vehicle 1, and causes a portion of the reflected light of the display light to be incident on the eye (viewpoint) 6 of an occupant (driver or passenger) 5 of the vehicle 1, thereby displaying an image (virtual image) V on a virtual image display surface PS that is virtually set in front of the vehicle 1 (in the Z direction).

[0050] The HUD device 100 has a processor (display control device) 36, an image processing unit 80, a light source unit 24 (including a display unit 22 having a flat panel display or the like), a plane mirror 26 and a curved mirror (concave mirror, etc.) 28 as an optical system, a rotation mechanism (including an actuator) 30 that rotates the curved mirror (concave mirror, etc.) 28, a curved mirror rotation control unit 31 that controls the rotation of the curved mirror 28, an input interface (input IF) 32, a memory (storage device or storage unit) 50, and a drawing memory 65.

[0051] The vehicle 1 is also provided with a gyro sensor 12 (including the roll angular velocity sensor 9 and the pitch angular velocity sensor 11) and a vehicle ECU (Electronic Control Unit) 13. In the following description, the "gyro sensor 12" may be simply referred to as the "sensor 12."

[0052] The processor (display control device) 36 is a display control device mounted on the vehicle 1 and controls the image display of the display device (HUD device) 100 that allows an occupant (viewer) 5 aboard the vehicle 1 to view an image (virtual image) V.

[0053] This processor (display control device) 36 has a vehicle vibration (pitching, rolling, etc.) information acquisition unit 40 that acquires vibration information (angular velocity information here) of the vehicle 1, a vehicle state determination unit 41 that determines whether the vehicle 1 is moving or stopped, a bias error correction value acquisition unit 42 that acquires a bias error correction value that corrects a bias error contained in the acquired vibration information (angular velocity information) during the stopped period of the vehicle 1, a bias error correction unit 43 that corrects the vibration information (angular velocity information) based on the acquired bias error correction value, a vehicle attitude fluctuation amount detection unit 44 that detects the amount of fluctuation in the attitude of the vehicle 1 based on the corrected vibration information, and a display correction unit 45 that changes at least one of the position and size of the image (virtual image) V to correspond to the detected amount of fluctuation in the attitude of the vehicle 1.

[0054] Here, when the latest bias error correction value acquired by the bias error correction value acquisition unit 42 is the "updated bias error correction value" and the bias error correction value before the update is the "previous bias error correction value", the bias error correction unit 43 executes at least one of a "first correction process" in which the "previous bias error correction value" is gradually changed over time and transitioned to the "updated bias error correction value" after the period of change, and a "second correction process" in which the transition operation of transitioning the previous bias error correction value to the updated bias error correction value is not performed while the vehicle is stopped but is performed while the vehicle is traveling.

[0055] The "first correction process" is a correction process that gradually changes the bias error correction value on the time axis, and the "second correction process" is a correction process that uses a kind of timing control in which the bias error correction is not performed when the vehicle is stopped, but only when the vehicle is moving. The details of these will be described later.

[0056] The memory 50 is provided with a correction table 52 (including a pitching correction table 54 and a rolling correction table 56). The display correction unit 45 in the processor (display control device) 36 can refer to the correction table 52 as appropriate when performing display correction.

[0057] Furthermore, when the display correction unit 45 performs a predetermined correction calculation for display correction, the correction calculation data 59 provided in the memory 50 can be used as appropriate.

[0058] The image processing unit 80 includes a bus 82, an image generation unit 84, a correction unit (image correction unit) 86, and an output buffer 88. The image generation unit 84 can appropriately use image data stored in the drawing memory 65 when generating an image.

[0059] The correction section (image correction section) 86 can change (correct) at least one of the display position of the image on the display section (flat panel display or the like) 22 of the light source section 24 and the size of the image.

[0060] The output buffer 88 supplies the image data output from the correction section (image correction section) 86 to the display section 22 of the light source section 24.

[0061] When the display correction unit 45 in the processor (display control device) 36 changes the display position of the image in response to an update of the bias error correction value, the display correction unit 45 supplies information on the changed display position of the image to at least one of the correction unit (image correction unit) 86 in the image processing unit 80 and the curved mirror rotation control unit 31.

[0062] The display position of the image on the display unit 22 or the size of the image is changed by the correction unit (image correction unit) 86, whereby the position and size of the image (virtual image) V on the virtual image display surface PS are changed.

[0063] In addition, the curved mirror rotation control unit 31 rotates the curved mirror (concave mirror, etc.) 28, thereby adjusting the position of the virtual image display surface PS (position in the vehicle's height direction (Y direction)), which also makes it possible to change the position of the image (virtual image) V.

[0064] Next, the above-mentioned "first correction process" will be described. The contents of the "first correction process" are shown in Fig. 3 and Fig. 4, but before describing these figures, a problem that was studied and identified by the present inventor before the present invention will be described with reference to Fig. 2 (this is a premise of the present invention and is not a publicly known technique).

[0065] FIG. 2 is a diagram showing problems associated with bias error correction that were considered by the present inventor prior to the present invention. In A-1 to A-5 of FIG. 2, the horizontal axis indicates the time axis, but this time axis also serves as a reference axis (axis on which the signal value is zero) for the various signals indicated on the vertical axis.

[0066] In FIG. 2, the vehicle 1 is in a traveling state from time t0 to t2, and the vehicle 1 transitions to a stopped state at time t3.

[0067] A-1 in FIG. 2 shows an example of a waveform (vibration waveform) of vibration information (specifically, pitch angular velocity or roll angular velocity) of the vehicle 1 output from the gyro sensor (hereinafter, sometimes simply referred to as the sensor) 12.

[0068] Here, at time t1, a change occurs in the amplitude of the vibration waveform, which is due to a fluctuation in the value of the bias error superimposed on the vibration waveform.

[0069] Shortly before time t2, the vehicle 1 essentially stops, and the vibration waveform is no longer output from the sensor. If there were no bias error, the sensor output value (angular velocity value) would be zero, but in A-1 of FIG. 2, the sensor output value (angular velocity value) is the DC component of "V1". This indicates the latest bias error value. Note that once the latest "bias error" is acquired, the bias error value can be used as is as the "bias error correction value". For example, if the bias error "V1" is superimposed on the vibration waveform indicating the angular velocity, the bias error correction for the angular velocity can be achieved by subtracting "V1" from the vibration waveform.

[0070] In other words, once the latest "bias error" is acquired, the "bias error correction value" is uniquely determined based on that "bias error". The above "V1" is the "bias error", but it can also be called the "bias error correction value". Taking this into consideration, in A-2 of FIG. 2, the vertical axis related to the vibration waveform is written as "bias error correction value". This is the same for FIG. 4, FIG. 6, and FIG. 8.

[0071] 2, the timing for updating the bias error correction value arrives at time t2. Therefore, at this time t2, the latest bias error V1 is acquired, and the bias error correction value V1 is uniquely determined.

[0072] As shown in A-2 of FIG. 2, the bias error correction value is "V0" from time t0 to t2, but the bias error correction value newly acquired at time t2 is "V1."

[0073] A-3 in Figure 2 shows an example of the waveform of the angle (before bias error correction) obtained by integrating the angular velocity. The bias error superimposed on the angle (pitch angle or roll angle) is "V2".

[0074] An example of a waveform showing the amount of variation in vehicle attitude (with bias error correction at time t2) is shown in A-4 of Fig. 2. The amount of variation in vehicle attitude can be obtained by calculating the amount of rotation (deviation from the reference attitude) around the "left-right axis" and "front-rear axis" of the vehicle based on the angle information obtained in A-3 of Fig. 2.

[0075] In A-4 of FIG. 2, from time t2 to time t3, as the bias error correction value is updated, the signal value indicating the attitude variation amount changes quite abruptly.

[0076] In A-5 of Fig. 2, the waveform of the display correction value is a waveform of opposite polarity to the posture variation amount in A-4 of Fig. 2. In A-5 of Fig. 2 as well, the display correction value changes quite abruptly from time t2 to t3. Accordingly, the display position of the image changes quite abruptly.

[0077] In this way, when bias error correction is performed while the vehicle is traveling, the display position of the image may change due to the bias error correction, and this change in display position may give an unpleasant feeling to the vehicle occupants (driver and passengers).

[0078] In particular, if a change in the display position of an image occurs due to bias error correction while the vehicle is stopped (for example, if an image is maintained in a state where it is superimposed on an object even while the vehicle is stopped, and the position of the superimposed image changes and becomes misaligned with the object), this is likely to be noticeable to occupants and cause discomfort. In other words, when the vehicle is stopped, the occupants do not need to gaze intently at the road ahead in order to drive safely, and can look ahead with ease. Also, since there is very little vibration in the vehicle while it is stopped, the occupants are more likely to see (perceive) sudden changes in the image position, and therefore are more likely to feel uncomfortable.

[0079] This problem was identified by the inventors' investigations prior to the invention. Next, a solution to this problem will be described.

[0080] Please refer to Fig. 3. Fig. 3 is a flowchart showing the main operation procedure of the display control device in the first embodiment.

[0081] In step S1, vibration information of the vehicle is acquired. In step S2, the vehicle state (running / stopped) is determined.

[0082] In step S3, if the vehicle is stopped (in other words, if Y), the process proceeds to step S4, and if N, the process proceeds to step S5.

[0083] In step S4, the moving average of the angular velocity is calculated, and the bias error correction value is updated. Specifically, the bias error correction value acquisition unit 42 shown in FIG. 1 calculates a moving average of the output values ​​of the sensor 12 that detects vibration information of the vehicle 1 each time the timing for updating the bias error correction value arrives while the vehicle 1 is stopped, and determines (acquires, updates) the bias error correction value based on the calculated moving average value. Since the bias error correction value is updated at any time during the stopped period, it is possible to respond to changes in the bias error over time.

[0084] During a period when the vehicle is stopped (including a period when the vehicle can be considered to be substantially stopped), the input of the sensor 12 (in other words, vibration due to pitching or rolling of the vehicle) is considered to be substantially zero (in other words, close to zero). In this case, if a non-zero output value is generated from the sensor 12, the output value indicates an error in the input / output of the sensor. However, the error varies over time.

[0085] Taking this into consideration, in step S4, a moving average of the output values ​​(e.g., angular velocity values) of the sensor 12 is calculated. A "moving average" is an average value of time-series data in a predetermined interval. When multiple predetermined intervals are set, the average of the data obtained in each interval may be calculated and used as the moving average. Calculating a moving average is easy, allows for high-speed calculation, and places little burden on the processor, etc.

[0086] The moving average value of the output value (e.g., angular velocity value) of the sensor 12 can also be called the bias error of the sensor 12. If there is a difference between the previous bias error and the latest bias error (updated bias error), the output value (e.g., angular velocity value) of the sensor 12 is corrected using the latest bias error. This improves, for example, the measurement accuracy of the amount of change in the vehicle's attitude.

[0087] In step S5, the bias error correction value is made to approach (by a small amount) the acquired (updated) bias error correction value, where ΔV is the amount of change (a small amount of change) per processing. For example, it is assumed that the bias error correction value is changed little by little at a frequency of 60 Hz (in other words, at a period of (1 / 60) seconds) when updating the bias error correction value. In this case, the timing arrives every (1 / 60) second to change the bias error correction value by the minute change amount ΔV. Each time this timing arrives, the bias error correction value changes by ΔV.

[0088] In other words, the bias error contained in the vibration information is corrected while the vehicle is running (a broad concept including the actual running state of the vehicle and the stopped state) based on the updated bias error correction value. However, if this bias error correction is performed unconditionally, the display position of the image will change every time the bias error is corrected, and this change may be noticeable to the occupants and cause them to feel uncomfortable.

[0089] Therefore, in the example of Fig. 3, a "first correction process" is performed. In the "first correction process", when the latest acquired bias error correction value is called an "updated bias error correction value" and the bias error correction value before the update is called a "previous bias error correction value", the "first correction process" is a correction process in which the "previous bias error correction value" is gradually changed over time and transitioned to the "updated bias error correction value" after a period of change.

[0090] According to the first correction process in step S5, the correction value of the bias error changes gradually over time, so that the corresponding movement of the image position is also gradual and there is no steep (step-like) movement, so that it is less noticeable to the vehicle occupants and the occupants are less likely to feel uncomfortable.

[0091] In step S6, the amount of change in the vehicle's attitude is detected based on the angular velocity (angle) corrected by the bias error correction value.

[0092] In step S7, the display (display position, etc.) is corrected based on the detected vehicle attitude. As described in step S5, the bias error correction value changes gradually over time by the "first correction process", so the corresponding movement of the image position also becomes gentle and does not become abrupt (step-like) movement, so that the image is less noticeable to the vehicle occupants, and discomfort felt by the occupants can be suppressed.

[0093] In a preferred embodiment, when the bias error correction value is acquired (updated) during a stop period of the vehicle 1, a first correction process (a correction process that gradually changes the bias error correction value over time) is performed during a period including the stop period. In other words, the bias error correction is performed during a period including the stop period. Here, the expression "a period including a stopped period" indicates that "the first correction process is started during that stopped period, but the first correction process may not be completed at the time driving starts, in which case the first correction process may be continued until the period in which the first correction process is completed, even after driving starts."

[0094] As a result, when vehicle 1 transitions from a stopped state to a running state, the image is displayed in the correct position from the beginning of the running state without being affected by bias error, and passengers can view a natural image from the beginning of the run.

[0095] Next, reference is made to Fig. 4. Fig. 4 is a waveform diagram showing the main operations of the display control device in the first embodiment.

[0096] A-1 in FIG. 4 is substantially the same as A-1 in FIG. 2 described above.

[0097] In A-2 of FIG. 4, the bias error correction value is updated at time t2. The previous bias error correction value is V0, and the updated bias error correction value is V1. Here, the transition (switching) from the previous bias error V0 to the updated bias error correction value V1 is gradually carried out over a predetermined period from time t2 to t4. In the example of A-2 of FIG. 4, the bias error correction value gradually changes over time along a straight characteristic line having a predetermined gradient.

[0098] A-3 in Fig. 4 shows a change in the waveform of the angle (angle information) obtained by integrating the angular velocity information when bias error correction is performed. In A-3 in Fig. 4 as well, the bias error superimposed on the angle (angle information) gradually approaches zero from time t2 to t4, and the bias error correction ends at time t4.

[0099] The waveform of the attitude fluctuation amount (with bias correction error) shown in A-4 of Fig. 4 is the same as the waveform of A-3 of Fig. 4. From time t2 to t4, the signal value indicating the attitude fluctuation amount gradually changes on the time axis as the bias error correction value changes.

[0100] In A-5 of Fig. 4, the waveform of the display correction value has a waveform of opposite polarity to the posture variation amount in A-4 of Fig. 2. The display correction value gradually changes on the time axis from time t2 to t4. Therefore, even if the bias error correction is performed during the stopping period (including the stopping period) in which the latest bias error was acquired, the change in the display position of the image becomes gentle, and it is possible to suppress the passengers (driver and passengers) of the vehicle from feeling uncomfortable.

[0101] Second Embodiment Please refer to Fig. 5. Fig. 5 is a flowchart showing the main operation procedure of the display control device in the second embodiment. In Fig. 5, the same steps as those in Fig. 3 described above are given the same reference numerals.

[0102] Steps S1 to S3, S6, and S7 in Fig. 5 are the same as those in Fig. 3. Explanation of the same steps as those in Fig. 3 will be omitted. In Fig. 5, steps S8 to S10 are added to the steps in Fig. 3.

[0103] In this embodiment, the first correction process (a correction process in which the correction value of the bias error is gradually changed over time) described in the first embodiment (FIGS. 3 and 4) is not performed while the vehicle is stopped, but is performed while the vehicle is traveling.

[0104] Here, in this specification, the correction process that imposes a condition on the correction timing, that is, "the update operation of the bias error correction value is not performed while the vehicle is stopped, but is performed while the vehicle is traveling", is referred to as a "second correction process".

[0105] According to this second correction process, the correction process of the bias error is performed during the driving period, avoiding the stopped period when the change in the image position is likely to be noticeable to the passenger, so that the passenger's discomfort can be suppressed.

[0106] In this embodiment, a first correction process (a correction process that gradually changes the bias error correction value over time) and a second correction process (a correction process that imposes a condition on the correction timing, that is, the transition operation of the bias error correction value is performed during the vehicle's running period) are used in combination.

[0107] Specifically, during the vehicle stop period, each time the timing for updating the bias error correction value arrives, the bias error correction value is acquired (updated), for example, by taking a moving average of the angular velocity, but the bias error correction using the updated bias error correction value is not performed during the vehicle stop period.

[0108] The bias error correction unit 43 shown in Fig. 1 performs a characteristic operation of updating the bias error correction value during the stopped period, waiting for the vehicle to enter a traveling period while maintaining (holding) the latest bias error correction value obtained as a result, and correcting the bias error using the latest bias error correction value that has been maintained (held) when the vehicle enters the traveling period. The steps for performing this characteristic operation are steps S8 to S10 in Fig. 5. In the following description, for convenience of explanation (for convenience of explaining the flowchart in a simplified manner), the term "bias error correction target value" is used. For example, in step S5 of FIG. 3 described above, it is described that "the bias error correction value is brought slightly closer (ΔV) to the acquired (updated) bias error correction value (where ΔV is the amount of change (small change amount) per processing)." In contrast, in FIG. 5, the expression "obtained (updated) bias error correction value" is replaced with "bias error correction target value" for convenience of explanation. From another perspective, the "acquired (updated) bias error correction value" can be considered as a "target value" indicating the end point when the bias error correction value is changed. Taking this into consideration, in the example of FIG. 5 (the same applies to the example of FIG. 7 described later), it is rephrased as the "bias error correction target value."

[0109] Steps S1 and S2 are the same as those in FIG. In step S3, if the vehicle is stopped (in other words, Y in step S3), the process proceeds to step S8, and if N, the process proceeds to step S10.

[0110] In step S8, it is determined whether it is time to update the bias error correction target value. If the answer is Y, the process proceeds to step S9, and if the answer is N, the process proceeds to step S6.

[0111] In step S9, a moving average of the angular velocity is calculated, and the bias error correction target value is updated. However, here, although the bias error correction target value is updated, the bias error correction value does not change and the current value is maintained. In other words, the bias error correction value changes when the process shown in step S10 is performed to bring the bias error correction value closer to the bias error correction target value. At the time of step S9, the bias error correction value has not changed.

[0112] Furthermore, there is no step corresponding to step S10 between step S9 and step S6. Therefore, when the process proceeds to steps S6 and S7 via step S9 (when the vehicle is stopped), the bias error correction value does not change and the current state is maintained. In other words, when the vehicle is stopped, no image correction is performed, and therefore the display position of the image does not change.

[0113] On the other hand, if step S3 is N (the vehicle is moving) and the process proceeds to step S10, a process is performed to bring the bias error correction value closer to the bias error correction target value (the bias error correction target value acquired in step S9 while the vehicle is stopped) by ΔV. In other words, the bias error correction value changes. Therefore, when the process proceeds to steps S6 and S7 through step S10 (when the vehicle is traveling), the bias error correction value has changed, and image correction based on the bias error correction is performed accordingly. In other words, when the vehicle is traveling, image correction is performed in response to the change in the bias error correction value, and the display position of the image changes little by little over time. The processor (display control device) 36 repeatedly executes the above steps to realize the first and second correction processes described above.

[0114] As described above, when the vehicle is stopped, the "bias error correction target value" is updated (calculated), but the bias error correction value itself is not corrected (step S9). Therefore, when the vehicle is stopped, image correction by bias error correction is not performed.

[0115] On the other hand, when the vehicle starts to move, a process is performed to bring the bias error correction target value closer to the bias error correction target value calculated when the vehicle stopped by a predetermined value (a small change amount "ΔV") (step S10). Therefore, when the vehicle is moving, image correction by bias error correction is performed.

[0116] In this way, according to the second embodiment, the first correction process, which gradually changes the bias error correction value over time, is not performed while the vehicle is stopped, but can be performed (second correction process) while the vehicle is traveling. By avoiding the stopped period when the passenger has relatively more time (and the vehicle vibration is extremely small) and performing the first correction process only while the vehicle is moving, the possibility that the passenger will perceive the change in the image position caused by the bias error correction is further reduced. Therefore, the possibility that the passenger will feel uncomfortable can be further reduced.

[0117] Next, reference is made to Fig. 6. Fig. 6 is a waveform diagram showing the main operations of the display control device in the second embodiment.

[0118] In FIG. 6, the vehicle is in a traveling state during the period from time t0 to t2, is in a stopped state during the period from time t2 to t5, and is in a traveling state during the period from time t5 to t7.

[0119] In A-1 of FIG. 6, the timing for updating the bias error correction value occurs twice during the vehicle stop period (times t2 and t5). As explained above, the "bias error correction target value" is calculated (updated) at each timing, but the "bias error correction value" itself is not corrected. Therefore, when the vehicle is stopped, image correction by bias error correction is not performed.

[0120] In A-2 of FIG. 6, the correction process based on the bias error correction value is performed during the vehicle's running period (the period from time t5 to t6). Specifically, at time t5 when the vehicle starts to travel, a process is performed to bring the bias error correction value closer to the “bias error correction target value” calculated while the vehicle was stopped by a predetermined value (a small change amount ΔV) (in A-2 of FIG. 6, a process of calculating the bias error correction value −ΔV is performed). Thereafter, the same process (calculation process of subtracting ΔV) is repeatedly performed every (1 / 60) seconds. As a result, the previous bias error correction value V0 is gradually changed over time to the updated bias error correction value V1 during the period from time t5 to t6.

[0121] At time t6, the update of the bias error correction value is completed. After time t6 (the period from time t6 to time t7 in FIG. 6), the correction of the angular velocity is performed using the bias error correction value V1 for which the transition has been completed.

[0122] In A-1 of FIG. 6, in the area indicated by the dashed ellipse (the period from time t6 to t7), accurate bias correction is performed using the bias error correction value V1 whose transition has been completed, and as a result, the angular velocity waveform becomes an accurate waveform that is symmetrical up and down.

[0123] In the figure, the portion enclosed by the dashed ellipse is indicated as a “bias error correction completed period.” In the period from time t5 to t6, the bias error correction value gradually changes over time, and this period can be called a “bias error correction value transition period.”

[0124] Also in each of A-2 to A-6 in FIG. 6, the period from time t6 to time t7 is the "bias error corrected period".

[0125] (Third embodiment) Please refer to Fig. 7. Fig. 7 is a flowchart showing the main operation procedure of the display control device in the third embodiment.

[0126] In the third embodiment, the second correction process described above (a correction process for performing bias error correction only while the vehicle is traveling) is performed. However, unlike the second embodiment, the first correction process (a correction process for gradually shifting the bias error correction value over time) is not performed.

[0127] In addition, when the second correction process is performed, during the vehicle stop period, the bias error correction value target value is updated every time the timing for updating the bias error correction value target value arrives, while waiting for the vehicle to transition to a running state. Then, when the vehicle transitions to a running state, the bias error correction is performed by transitioning the previous bias error correction value to the latest bias error correction value updated while the vehicle was stopped. This allows accurate bias error correction to be performed based on the latest bias error correction value.

[0128] In addition, by avoiding the stopped period when the passenger has a relatively relaxed time (and the vehicle vibration is very small) and performing the second correction process only while the vehicle is moving, the possibility that the passenger will notice the change in the image position caused by the bias error correction is reduced. Therefore, the possibility that the passenger will feel uncomfortable can be reduced.

[0129] Fig. 7 is almost the same as Fig. 5 described above. Explanation of steps common to Fig. 5 will be omitted. However, in Fig. 7, step S10 in Fig. 5 is replaced with step S11, which is a difference.

[0130] In step S11 in Fig. 7, a correction process is performed to update the previous bias error correction value to the acquired bias error correction value while the vehicle is in a traveling state. However, the correction process (first correction process) in which the bias error correction value is gradually changed over time as in step S10 in Fig. 5 is not performed.

[0131] Please refer to Fig. 8. Fig. 8 is a waveform diagram showing the main operations of the display control device in the third embodiment.

[0132] In A-1 of Fig. 8, two timings for updating the bias error correction value arrive while the vehicle is stopped (times t2 and t5). At these timings, the bias error correction value is acquired (updated) as needed. Note that time t5 is the end point of the period when the vehicle is stopped and also the start point of the vehicle starting to move.

[0133] As described above, time t5 is also the time when the vehicle starts traveling, so in A-2 of FIG. 8, at time t5, the previous bias error correction value V0 immediately transitions to the latest bias error correction value V1 (in other words, the bias error correction value is immediately switched).

[0134] In the waveform of the angle information of A-3 in Fig. 8, the bias error V2 is immediately corrected at time t5, and a vibration waveform that is almost symmetrical vertically is obtained in the period from time t5 to t6. In the figure, the period indicated by the dashed ellipse is the bias error correction period.

[0135] In A-4 and A-5 of Fig. 8, some disturbance in the waveform occurs immediately after time t5, but in the period from time t5 to t6, a vibration waveform in which the bias error is substantially corrected is obtained. In A-4 and A-5 of Fig. 8, the period indicated by the dashed ellipse in the figure is the bias error corrected period.

[0136] As described above, according to the present invention, it is possible to realize a display control device, a display device, and a display control method that are capable of appropriately correcting bias error contained in vehicle vibration information without causing discomfort to vehicle occupants.

[0137] The display device is broadly interpreted and can be applied to, for example, a head-up display (HUD) device or other display device. As the display device, a liquid crystal display device, a micro LED device, or other various display devices can be used.

[0138] In this specification, the term "vehicle" may be broadly interpreted as a vehicle. Terms related to navigation (e.g., signs, etc.) are also broadly interpreted, taking into consideration the perspective of navigation information in a broad sense that is useful for driving a vehicle. HUD devices also include those used as simulators (e.g., aircraft simulators, simulators as game devices, etc.).

[0139] The present invention is not limited to the above-described exemplary embodiments, and those skilled in the art could easily modify the above-described exemplary embodiments to the extent that they fall within the scope of the claims. [Explanation of symbols]

[0140] 1···vehicle (own vehicle), 2···windshield (projected member), 5···occupant (driver or passenger), 6···viewpoint (eyes), 9···roll angular velocity sensor, 11···pitch angular velocity sensor, 12···gyro sensor (sensor), 13···vehicle ECU (Electronic Control Unit), 22···display unit (flat panel display, etc.), 24···light source unit, 26···flat mirror, 28···curved mirror (concave mirror, etc.), 30···curved mirror rotation mechanism, 31···curved mirror rotation control unit, 32···input interface (input IF), 36···processor (display control device), 40··vehicle vibration (pitching, rolling, etc.) information acquisition unit, 41···vehicle state determination unit, 42···bias error correction value acquisition unit, 43···bias error correction value acquisition unit error correction unit, 44...vehicle attitude change amount detection unit, 45...display correction unit, 50...memory (storage device, storage unit), 52...correction table, 54...pitching correction table, 56...rolling correction table, 59...correction calculation data, 65...drawing memory, 80...image processing unit, 82...bus, 84...image generation unit, 86...correction unit (image correction unit), 88...output buffer, 100...head-up display device (HUD device).

Claims

1. A display control device that controls image display of a display device mounted on a vehicle and allows a passenger in the vehicle to view an image, a vehicle vibration information acquisition unit that acquires vibration information of the vehicle; a vehicle state determination unit that determines whether the vehicle is moving or stopped; a bias error correction value acquisition unit that acquires a bias error correction value for correcting a bias error included in the acquired vibration information during a stop period of the vehicle; a bias error correction unit that corrects the vibration information based on the acquired bias error correction value; a vehicle attitude fluctuation amount detection unit that detects an amount of fluctuation in the attitude of the vehicle based on the corrected vibration information; a display correction unit that changes at least one of a position and a size of the image so as to correspond to an amount of change in the attitude of the vehicle that has been detected; having The bias error correction unit In the case where the latest bias error correction value acquired by the bias error correction value acquisition unit is an updated bias error correction value, and the bias error correction value before the update is performed is a previous bias error correction value, a first correction process in which the previous bias error correction value is gradually changed over time and transitioned to the updated bias error correction value after a period of change; And, a second correction process in which a transition operation of transitioning the previous bias error correction value to the updated bias error correction value is not performed during a period in which the vehicle is stopped, but is performed during a period in which the vehicle is traveling; Implement at least one of the following: Display control device.

2. The bias error correction value acquisition unit calculating a moving average of an output value of a sensor that detects vibration information of the vehicle at each update timing of a bias error correction value during a period when the vehicle is stopped, and determining the bias error correction value based on the calculated moving average value; The display control device according to claim 1 .

3. The bias error correction unit When the first correction process is performed, The first correction process is performed during a period including a vehicle stop period during which the bias error correction value acquisition unit acquires the bias error correction value. The display control device according to claim 1 .

4. The bias error correction unit The first and second correction processes are used in combination, whereby the first correction process is not performed during a period when the vehicle is stopped, but is performed during a period when the vehicle is traveling. The display control device according to claim 1 .

5. The bias error correction value acquisition unit When the second correction process is performed, during a period in which the vehicle is stopped, acquiring the bias error correction value at each update timing of the bias error correction value, and waiting for the vehicle to transition to a traveling state; When the vehicle is in a running state, the previous bias error correction value is transitioned to the latest updated bias error correction value. The display control device according to claim 1 .

6. The vibration information of the vehicle is angular velocity or acceleration information in at least one of pitching and rolling of the vehicle. The display control device according to claim 1 .

7. A display control device according to any one of claims 1 to 6, a display unit in which image display is controlled by the display control device; A display device having the above configuration.

8. The display device includes: The head-up display device further includes an optical system that projects a display light of an image displayed on the display unit onto a projection target member provided in the vehicle, and has a function of allowing the passenger to visually recognize a virtual image. The display device according to claim 7.

9. A display control method for a display device mounted on a vehicle, comprising: acquiring a bias error correction value for correcting a bias error included in vibration information of the vehicle during a stopped period of the vehicle; correcting the vibration information based on the bias error correction value; detecting an amount of change in the attitude of the vehicle based on the corrected vibration information; changing at least one of a position and a size of the image in response to a detected amount of change in the attitude of the vehicle; Including, In the case where the latest bias error correction value acquired by the step of acquiring the bias error correction value is an updated bias error correction value, and the bias error correction value before the update is performed is a previous bias error correction value, a first correction process in which the step of correcting the vibration information is performed by gradually changing the previous bias error correction value over time and transitioning to the updated bias error correction value after a period of change; And, a second correction process in which a transition operation of transitioning the previous bias error correction value to the updated bias error correction value is not performed during a period in which the vehicle is stopped, but is performed during a period in which the vehicle is traveling; Implement at least one of the following: Display control method.

Images