JP7057327B2 - Display control device - Google Patents

Description

The present disclosure relates to a technique for controlling display by an in-vehicle display.

A head-up display (hereinafter referred to as AR-HUD) having an AR function for superimposing a virtual image on an object in a landscape outside a vehicle that can be seen through a windshield is known. AR is an abbreviation for Augmented Reality and is translated as augmented reality. HUD is an abbreviation for Head Up Display. The AR-HUD has a problem that the superimposed position of the virtual image in the landscape shifts due to the change in the pitch angle and the roll angle of the vehicle.

In Patent Document 1 below, the vehicle posture is estimated using an angle sensor and a roll sensor, and the angle of the mirror that projects the image on the windshield and the display position in the image are adjusted based on the estimated vehicle posture. As a result, a technique for suppressing the misalignment of the virtual image is disclosed.

International Publication No. 2018/042898

However, as a result of detailed examination by the inventor, in the prior art described in Patent Document 1, it is necessary to use two expensive sensors in order to estimate the vehicle posture, and moreover, the vehicle posture is obtained from the detection result by the sensors. There was a problem that the calculation load for calculating was high. Further, when the position of the driver's eyes shifts due to the behavior of the vehicle, there is also a problem that the position shift of the virtual image becomes large.

One aspect of the present disclosure is to provide a technique for accurately suppressing a misalignment of a virtual image superimposed and displayed on an object by a simple method.

One aspect of the present disclosure is a display control device, which includes an information generation unit (101), a vehicle height acquisition unit (102: S140), an acceleration acquisition unit (102: S150), and a characteristic storage unit (8). A correction amount calculation unit (102: S160), a pitch angle calculation unit (102: S170), an eye information acquisition unit (102: S180), and a projection correction unit (102: S190) are provided.

The information generation unit acquires information on the object existing in the landscape visible to the driver via the projection area, and the projection area of the superimposed image superimposed on the object according to the three-dimensional position information of the object. Set the projection position within. The projection area is an area in the front window of the vehicle on which an image to be recognized as a virtual image by the driver is projected. The vehicle height acquisition unit acquires a vehicle height detection value representing a displacement amount of the vehicle height of the vehicle. The acceleration acquisition unit acquires lateral acceleration, which is the acceleration applied in the vehicle width direction of the vehicle. The characteristic storage unit stores conversion information showing the correlation between the lateral acceleration and the displacement amount of the vehicle height detection value. The correction amount calculation unit calculates the correction amount of the vehicle height detection value by using the lateral acceleration acquired by the acceleration acquisition unit and the conversion information stored in the characteristic storage unit. The pitch angle calculation unit uses the value obtained by correcting the vehicle height detection value acquired by the vehicle height acquisition unit with the correction amount calculated by the correction amount calculation unit, and is the pitch angle which is the inclination angle of the vehicle in the front-rear direction. Is calculated. The eye information acquisition unit acquires eye information, which is a detection result of the amount of deviation of the driver's eye position from the reference position. The projection correction unit corrects the projection position of the superimposed image set by the information generation unit according to both the pitch angle and the eye information so that the superimposed image visually recognized by the driver is superimposed and displayed on the object.

According to such a configuration, even when the vehicle is turning, an error occurs in the vehicle height detection value. Therefore, the error is suppressed by the correction amount calculated based on the lateral acceleration, so that the vehicle height detection value can be used as the vehicle height detection value. The pitch angle can be calculated accurately. Further, since the projection position of the superimposed image is corrected according to not only the calculated pitch angle but also the position of the driver's eyes, it is possible to accurately suppress the positional deviation of the virtual image visually recognized by the driver from the object.

It is a block diagram which shows the structure of an information display system. It is explanatory drawing which shows the projection area. It is explanatory drawing which shows the arrangement of a HUD apparatus and the like. It is a flowchart of the process executed by the position correction part. It is explanatory drawing which shows the relationship between the change of the pitch angle and the deviation of the eye position, and the superimposition display position on the HUD display surface. It is explanatory drawing which shows the simplified model which shows the relationship between the detection value of a height sensor, and the vehicle pitch angle. It is explanatory drawing about the centrifugal force applied to a vehicle. It is explanatory drawing which shows the parameter necessary for explaining the relationship between the centrifugal force applied to a vehicle, and a vehicle roll angle. It is explanatory drawing which shows the relationship of each parameter when there is a cross slope. It is a graph which shows the result of having measured the error of the vehicle pitch angle detected when a centrifugal force is applied to a vehicle, and the error of the vehicle pitch angle to which the correction based on the centrifugal force is added.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
[1. Constitution]
The information display system 1 shown in FIGS. 1 to 3 is mounted on a vehicle and used. Hereinafter, the vehicle equipped with the information display system 1 is referred to as a own vehicle. The information display system 1 includes a display control device 10. The information display system 1 includes a peripheral monitoring unit 2, a behavior detection unit 3, a driver detection unit 4, a map storage unit 5, a positioning unit 6, a navigation device 7, a characteristic storage unit 8, and a head-up display ( Hereinafter, the HUD) device 9 may be provided. HUD is an abbreviation for Head Up Display. Each part constituting the information display system 1 may send and receive information via the in-vehicle LAN. LAN is an abbreviation for Local Area Network.

The information display system 1 projects an image on the windshield 120 located in front of the driver's seat by the HUD device 9, and displays various information on the actual scenery visually recognized by the driver through the windshield 120. In the following, an image displayed superimposed on such an actual landscape is referred to as an AR image. AR is an abbreviation for Augmented Reality.

The peripheral monitoring unit 2 includes at least one of a radar sensor and a camera. The radar sensor uses infrared rays, millimeter waves, ultrasonic waves, etc. as radar waves, and detects the distance from the target that reflects the radar wave, the direction in which the target exists, and the like. As the camera, a visible light camera, an infrared camera, or the like is used. The camera is arranged so as to include a region visually recognized by the driver through the windshield (hereinafter referred to as a visible region) as an imaging range. Like the camera, the radar sensor is arranged so as to include the viewing area as the detection range.

The peripheral monitoring unit 2 detects a target existing on the traveling path of the own vehicle with a radar sensor and a camera, and generates target information including the position of the detected target. The detection target of the peripheral monitoring unit 2 includes, for example, various targets to be processed by the advanced driver assistance system (that is, ADAS: Advanced Driver Assistance System). The peripheral monitoring unit 2 may generate target information including the position of the target based on the map information stored in the map storage unit 5, which will be described later.

The behavior detection unit 3 outputs various sensors that output a signal indicating a driving operation by the driver, a signal indicating the behavior of the own vehicle as a result of the driving operation, and a signal indicating the state of the vehicle that affects the behavior of the own vehicle. including.

The behavior detection unit 3 includes at least a height sensor 31, an acceleration sensor 32, a seat sensor 33, and a trunk sensor 34.
The height sensor 31 is provided on one of the wheels of the own vehicle, and outputs a detection signal according to the relative displacement amount (hereinafter referred to as vehicle height detection value) H between the axle of the wheel and the vehicle body. In this embodiment, it is provided on the right rear wheel.

The acceleration sensor 32 detects the magnitude of lateral acceleration, which is the acceleration in the vehicle width direction applied to the own vehicle. The acceleration value is represented by a plus sign for the acceleration applied to the right toward the traveling direction of the own vehicle, and is represented by a minus sign for the acceleration applied to the left.

The seat sensor 33 is provided on each of the occupant seats of the own vehicle, and outputs a detection signal indicating the presence or absence of an occupant on each occupant seat. Here, there are a driver's seat (hereinafter, D seat), a passenger seat (hereinafter, P seat), a rear right seat (hereinafter, RR seat), and a rear left seat (hereinafter, RL seat).

The trunk sensor 34 is provided in the trunk located near the rear end of the own vehicle, and outputs a detection signal indicating the presence or absence of luggage in the trunk. The seat sensor 33 and the trunk sensor 34 may be configured to output a detection signal indicating the weight of a load such as a occupant or luggage. The position where the seat sensor 33 and the trunk sensor 34 are installed corresponds to the measurement position.

In addition to the height sensor 31, the acceleration sensor 32, the seat sensor 33, and the trunk sensor 34, the behavior detection unit 3 includes, for example, an accelerator pedal sensor, a brake pedal sensor, a steering angle sensor, a direction indicator, a vehicle speed sensor, and a yaw rate sensor. Etc. may be included.

The driver detection unit 4 is a device that detects the driver's state such as the face position, face orientation, eye position, and line-of-sight direction from the driver's face image captured by the in-vehicle camera. The driver detection unit 4 is known as a so-called driver status monitoring system (that is, DSM: Driver Status Monitoring system).

Map information, AR information, and the like are stored in the map storage unit 5. The map information is used for route guidance by the navigation device 7 and for superimposing an AR image on the actual landscape.
Map information includes information on roads, lane markings such as white lines, information on road markings, and information on structures. The information about the road includes, for example, position information for each point, curve curvature and slope, and shape information such as connection relationship with other roads. Information on lane markings and road markings includes, for example, lane marking and road marking type information, location information, and three-dimensional shape information. The information about the structure includes, for example, type information, position information, and shape information of each structure. Here, the structure includes road signs, traffic lights, street lights, tunnels, overpasses, buildings facing the road, and the like.

The map information has the above-mentioned position information and shape information in the form of point cloud data, vector data, or the like of feature points represented by three-dimensional coordinates. That is, the map information represents a three-dimensional map including altitude in addition to latitude and longitude with respect to position information. Therefore, from the map information, it is possible to extract information on the slope of the road at each point on the road, specifically, a longitudinal slope along the traveling direction of the road and a cross slope along the width direction of the road. The location information contained in the map information has a relatively small error on the order of centimeters. The map information is highly accurate map data in that it has position information based on three-dimensional coordinates including height information, and it is also highly accurate in that the error in the position information is relatively small. It is data.

The AR information is data used for displaying an AR image, and includes symbols, characters, icons, and the like that are superimposed and displayed on the background. The AR information may include information for route guidance linked with the navigation device 7 (for example, an arrow superimposed on the road surface).

The positioning unit 6 is a device that generates position information for specifying the current position of the own vehicle. The positioning unit 6 includes, for example, a GNSS receiver and sensors for autonomous navigation such as a gyroscope and a distance sensor. GNSS is an abbreviation for Global Navigation Satellite System. The GNSS receiver receives the transmission signal from the artificial satellite and detects the position coordinates and altitude of the vehicle. The gyroscope outputs a detection signal according to the angular velocity of the rotational motion applied to the vehicle. The distance sensor outputs the mileage of the vehicle. The positioning unit 6 calculates the current position of the own vehicle based on the output signals from these devices. The positioning unit 6 generates highly accurate position information and the like of the vehicle by combined positioning that combines the information from the GNSS receiver and the information from the sensor for autonomous navigation. The positioning unit 6 has an accuracy of identifying the lane in which the vehicle travels among a plurality of lanes, for example.

The navigation device 7 provides route guidance based on the current position of the own vehicle and map data. The navigation device 7 identifies the current position and the traveling direction of the own vehicle on the road by the positioning result of the positioning unit 6 and the map matching using the map data. The navigation device 7 provides the display control device 10 with map information, AR information, and the like regarding the current position and direction of travel of the own vehicle, the route to the destination, the roads and facilities existing in the visual area of the driver, and the like.

The characteristic storage unit 8 includes a non-volatile memory. At least the pitch angle conversion information Gp and the correction amount conversion information Gh are stored in the characteristic storage unit 8 as characteristic information. The pitch angle conversion information Gp is information used when calculating the vehicle pitch angle from the vehicle height detection value H. The correction amount conversion information Gh is information used when calculating the correction amount ΔH of the detection value H of the height sensor 31 from the detection value (that is, lateral acceleration) of the acceleration sensor 32. The characteristic information Gp and Gh may be expressed by mathematical formulas or by table format data. In particular, a plurality of types of pitch angle conversion information Gp are prepared according to the detection results of the seat sensor 33 and the trunk sensor 34, that is, the load state specified from the arrangement of the occupants and the load in the vehicle.

For example, the seat sensor 33 detects the presence or absence of a occupant in each of the four occupant seats (that is, the D seat, the P seat, the RR seat, and the RL seat), and the trunk sensor 34 detects the presence or absence of luggage in one trunk. do. In this case, there are 32 patterns of load states depending on the presence or absence of the load (that is, occupants or luggage) at the above five locations. However, assuming that the D seat always has an occupant, the load state is 16 patterns. Although characteristic information may be prepared for each of the 16 patterns, the number of characteristic information may be reduced by integrating patterns in a load state having similar conversion characteristics. Specifically, for example, the four patterns may be classified according to the presence / absence of a P-seat occupant and the presence / absence of luggage in the trunk, or the two patterns may be classified only by the presence / absence of a P-seat occupant.

As shown in FIGS. 2 and 3, the HUD device 9 is arranged on the instrument panel 110. The HUD device 9 includes a projector 91 and an optical system 92. The projector 91 includes a liquid crystal display (hereinafter referred to as LCD) panel and a backlight. The projector 91 is fixed with the display screen of the LCD panel facing the optical system 92. The projector 91 displays an image on the LCD panel according to an instruction from the display control device 10, transmits light by a backlight, and emits light formed as a virtual image toward the optical system 92. The optical system 92 has at least a concave mirror, reflects and magnifies the light emitted from the projector 91, and projects it onto a projection area 121, which is an area on the windshield 120 set in the driver's viewing area. do. As a result, the AR image is superimposed and displayed on the actual landscape in the visible area of the driver.

The display control device 10 includes a microcomputer having a CPU 11 and a semiconductor memory (hereinafter, simply memory 12) such as a ROM or RAM. Each function of the display control device 10 is realized by the CPU 11 executing a program stored in a non-transitional substantive recording medium. The display control device 10 is also called an HCU. HCU is an abbreviation for HMI Control Unit, and HMI is an abbreviation for Human Machine Interface.

The display control device 10 includes an information generation unit 101 and a position correction unit 102 as a functional configuration realized by executing a program stored in the memory 12.
The information generation unit 101 is visually recognized via the projection area 121 based on the detection result of the peripheral monitoring unit 2, the route information from the navigation device 7, the map information, and the like, and is the target of providing information to the driver. Extract the target object. The information generation unit 101 generates position information representing the three-dimensional position of the object and an AR image superimposed on the object. At this time, based on the three-dimensional position of the object and the standard eye position of the driver, when the vehicle is in the standard load state where only the driver is on board, the AR image is superimposed on the object and recognized. As such, the projection position of the AR image in the projection area 121 is set.

The position correction unit 102 is generated by the information generation unit 101 based on the detection results of the sensors 31 to 34 and the vehicle pitch angle calculated from the characteristic information Gp and Gh stored in the characteristic storage unit 8. The projection position of the AR image in the projection area 121 is corrected.

The display control device 10 causes the HUD device 9 to display an AR image generated by the information generation unit 101 and whose projection position has been corrected by the position correction unit 102.
[2. process]
Next, the process executed by the display control device 10 in order to realize the function as the position correction unit 102 will be described with reference to the flowchart of FIG. This process is executed when the power supply to the HUD device 9 is started and the display becomes possible.

In S110, the display control device 10 acquires the detection results of the seat sensor 33 and the trunk sensor 34 as load detection values representing the load state applied to the vehicle. Here, the presence / absence of an occupant and the presence / absence of a load such as luggage are used as the load detection value.

In the following S120, the display control device 10 acquires the pitch angle conversion information Gp corresponding to the load state indicated by the load detection value from the characteristic storage unit 8.
In the following S130, the display control device 10 determines the current position acquired from the positioning unit 6, that is, the gradient information ψv, ψh regarding the road gradient of the road on which the own vehicle is traveling, based on the map information stored in the map storage unit 5. To get.

The gradient information ψv is information about a longitudinal gradient, and the gradient information ψh is information about a transverse gradient. The gradient information ψv is represented by a plus sign value if the longitudinal gradient is a forward gradient, and is represented by a negative sign value if the longitudinal gradient is a backward gradient. Further, the gradient information ψh is represented by a plus sign value if the cross slope is a right slope, and is represented by a minus sign value if the cross slope is a left slope.

In the following S140, the display control device 10 acquires the vehicle height detection value H, which is the detection value of the height sensor 31.
In the following S150, the display control device 10 acquires the lateral acceleration α, which is the detection result of the acceleration sensor 32.

In the following S160, the display control device 10 detects the vehicle height using the lateral acceleration α acquired in S150, the gradient information ψh of the transverse gradient acquired in S130, and the correction amount conversion information Gh stored in the characteristic storage unit 8. The correction amount ΔH with respect to the value H is calculated. The method of calculating the correction amount ΔH will be described later.

In the following S170, the display control device 10 calculates the vehicle pitch angle θ, which is the tilt angle of the vehicle body in the front-rear direction with respect to the horizontal plane, using the equation (1). However, Gp is the pitch angle conversion information acquired in S120, ψp is the gradient information of the longitudinal gradient acquired in S130, H is the vehicle height detection value acquired in S140, and ΔH is S160. It is a correction amount for the calculated vehicle height detection value H. Further, Gp (X) is a vehicle pitch angle estimated from the pitch angle conversion information Gp with the vehicle height detection value as X. C is an experimentally determined constant.

続くＳ１８０では、表示制御装置１０は、ドライバ検知部４で検知されるドライバの眼位置を表す眼情報を取得する。眼情報は、標準的な眼位置からのずれ量で表される。

In the following S180, the display control device 10 acquires eye information indicating the eye position of the driver detected by the driver detection unit 4. Eye information is represented by the amount of deviation from the standard eye position.

In the following S190, the display control device 10 in the projection region 121 based on the vehicle tilt angle θ calculated in S170, the eye information acquired in S180, and the three-dimensional position of the object on which the AR image is superimposed. The correction amount of the projection position of the AR image is calculated. The projected position of the AR image generated by the information generation unit 101 is corrected by this correction amount, and the AR image is supplied to the HUD device 9.

In the following S200, the display control device 10 determines whether or not the end condition is satisfied, returns the process to S130 if the end condition is not satisfied, and ends the process if the end condition is satisfied. The display control device 10 determines that the end condition is satisfied, for example, when the ignition switch is turned off or when a command to stop the operation of the HUD device 9 is input.

In the above process, S110 corresponds to the load acquisition unit, S140 corresponds to the vehicle height acquisition unit, S130 corresponds to the gradient acquisition unit, and S150 corresponds to the acceleration acquisition unit. Further, S160 corresponds to a correction amount calculation unit, S170 corresponds to a pitch angle calculation unit, S180 corresponds to an eye information acquisition unit, and S190 corresponds to a projection correction unit.

[3. How to calculate the amount of correction]
Next, the outline of the process for calculating the correction amount of the projection position of the AR image performed in S190 will be described with reference to FIG.

Here, for the sake of simplicity, a case where the longitudinal gradient is ψv = 0 ° will be described.
A case where the vehicle pitches and the vehicle body leans forward will be described. The eye position of the driver is represented by Ei, the projection area 121 is represented by Di, and the position where the light imaged as a virtual image is emitted, that is, the position of the projector 91 is represented by Si. Note that i = 0 indicates a position when the vehicle pitch angle is θ = 0 °, and i = 1 indicates a position when the vehicle pitch angle is θ> 0 °.

The driver's eye position E0, projection area D0, and light emission position S0 all change to positions E0 → E1, D0 → D1, S0 → S1 rotated by an angle θ with the vehicle center of gravity J as the center of rotation when the vehicle tilts forward. Moving.

When the vehicle pitch angle is θ = 0 °, that is, when the eye position is at E0, in the AR image superimposed on the object O, the straight line connecting the eye position E0 and the object O intersects the projection area D0. It needs to be projected at the position Pa.

When the vehicle pitch angle is θ> 0 °, that is, when the eye position is at E1, in the AR image superimposed on the object O, the straight line connecting the eye position E1 and the object O intersects the projection area D1. It needs to be projected on the position Pb.

That is, the projection position Pb in the projection area D1 is a position shifted upward as compared with the projection position Pa in the projection area D0.
Further, when the vehicle tilts forward, the driver's posture is displaced and the eye position is displaced, and when the eye position E2 is located at a position lower than the eye position E1, the AR image superimposed on the object O is displayed. It needs to be projected on the position Pc on the projection area D1.

That is, the projection position Pc when the eye position is displaced is shifted downward as compared with the projected position Pb when the eye position is not displaced.
In this way, the AR image is obtained by summing the correction amount according to the vehicle pitch angle θ, that is, the deviation amount from Pa to Pb, and the correction amount caused by the deviation of the eye position, that is, the deviation amount from Pb to Pc. The correction amount of the projection position of is calculated.

[4. Pitch angle conversion information]
The pitch angle conversion information ψp stored in the characteristic storage unit 8 will be described.
Using the simple two-wheel model shown in FIG. 6, the relationship between the vehicle height detection value H and the vehicle pitch angle θ is theoretically derived. Here, the distance from the front wheel to the position of the center of gravity of the load applied to the vehicle is a, and the distance from the front wheel to the rear wheel is b. The spring constant of the front suspension is Kf, the spring constant of the rear suspension is Kr, the displacement amount of the front suspension is xf, and the displacement amount of the rear suspension is xr. Let F be the load applied to the vehicle by the occupants and the load, and θ be the vehicle pitch angle, which is the tilt angle of the vehicle body due to this load.

Equation (2) can be obtained from the balance of forces, and equation (3) can be obtained from the balance of moments around the front.

（３）式をｘｒについて解くと（４）式が得られ、（４）式を（２）式に代入して整理すると（５）式が得られる。

Solving Eq. (3) for xr gives Eq. (4), and substituting Eq. (4) into Eq. (2) for rearrangement gives Eq. (5).

このとき、車両ピッチ角θは、（６）式で表され、これをθについて解くことで（７）式が得られる。

At this time, the vehicle pitch angle θ is expressed by Eq. (6), and by solving this with respect to θ, Eq. (7) can be obtained.

つまり、ハイトセンサ３１によってｘｆが得られれば、（５）式からＦを求めることができ、そのＦを用いて、（４）式からｘｒが算出される。同様に、ハイトセンサ３１によってｘｒが得られれば、（４）式からＦを求めることができ、そのＦを用いて、（５）式からｘｆが算出される。

That is, if xf is obtained by the height sensor 31, F can be obtained from the equation (5), and xr is calculated from the equation (4) using the F. Similarly, if xr is obtained by the height sensor 31, F can be obtained from the equation (4), and xf is calculated from the equation (5) using the F.

The vehicle pitch angle θ can be obtained by using the values of xf and xr thus obtained and the equation (7). From this relationship, it can be seen that there is a corresponding relationship between the vehicle height detection value H (that is, xf or xr) and the vehicle pitch angle θ.

[5. Correction value conversion information]
The correction amount conversion information Gh stored in the characteristic storage unit 8 will be described.
First, the centrifugal force Fc will be described with reference to FIG. 7. When the vehicle turns, centrifugal force Fc is generated in the left-right direction. When the lateral acceleration α of the vehicle can be detected, the centrifugal force Fc is calculated by the equation (8) with the mass of the vehicle as M. Further, when the vehicle speed V and the turning radius R of the vehicle are obtained, the centrifugal force Fc is calculated by the equation (9).

ところで、遠心力Ｆｃは、車両のロール角を変化させ、その結果、ハイトセンサ３１の検出値である車高検出値Ｈを変化させる。ハイトセンサ３１が右後輪に配置されている場合、車高検出値Ｈは、左旋回時には、実際の車高より低い値が検出され、右旋回時には、実際の車高より高い値が検出される。但し、このとき、ピッチ角θに変化は生じない。つまり、車両の旋廻中に、車高検出値Ｈからピッチ角変換情報Ｇｐを用いてピッチ角θを推定すると、推定されたピッチ角θには、遠心力Ｆｃにより発生する車両検出値Ｈの誤差が含まれる。

By the way, the centrifugal force Fc changes the roll angle of the vehicle, and as a result, changes the vehicle height detection value H which is the detection value of the height sensor 31. When the height sensor 31 is arranged on the right rear wheel, the vehicle height detection value H is detected to be lower than the actual vehicle height when turning left, and is detected to be higher than the actual vehicle height when turning right. Will be done. However, at this time, the pitch angle θ does not change. That is, when the pitch angle θ is estimated from the vehicle height detection value H using the pitch angle conversion information Gp during the rotation of the vehicle, the estimated pitch angle θ is an error of the vehicle detection value H generated by the centrifugal force Fc. Is included.

Here, the relationship with the displacement amount Hc of the height sensor 31 due to the centrifugal force Fc will be described with reference to FIGS. 8 and 9.
As shown in FIG. 8, the tread width of the vehicle is T, the vehicle weight of the rear wheel portion of the vehicle is Mr, the height of the center of gravity of the vehicle is h, and the spring constant of the suspension of the rear wheels is Kr. The vehicle weight Mr is a value obtained by multiplying the mass of the rear wheel portion of the vehicle by the gravitational acceleration. Further, the right load, which is the load applied to the right rear wheel, is Wr, and the left load, which is the load applied to the left rear wheel, is Wl.

First, a case where the cross slope of the road is ψh = 0 ° will be described.
Equation (10) is obtained from the balance of the moment around the left rear wheel by the centrifugal force Fc. Further, the right load Wr applied to the right rear wheel by the moment by modifying the equation (10) is expressed by the equation (11).

右荷重Ｗｒと、ハイトセンサ３１の変位量Ｈｃとの関係は、（１２）式で表される。従って、（１２）式の右荷重Ｗｒの項に、（１１）式を代入することで、遠心力Ｆｃと変位量Ｈｃとの関係式が得られる。

The relationship between the right load Wr and the displacement amount Hc of the height sensor 31 is expressed by the equation (12). Therefore, by substituting the equation (11) into the term of the right load Wr in the equation (12), the relational expression between the centrifugal force Fc and the displacement amount Hc can be obtained.

次に、横断勾配がψｈ≠０°の場合について説明する。

Next, a case where the cross slope is ψh ≠ 0 ° will be described.

As shown in FIG. 9, in this case, the vehicle weight applied to the right rear wheel is Mr. cos ψh due to the cross gradient ψh. Further, due to the transverse gradient ψh, a force having a magnitude of Mr. sin ψh acts in the direction opposite to the centrifugal force Fc. Therefore, the right load Wr in this case is expressed by the equation (13). However, assuming that ψh << 1, cos ψh≈1 and sinψh≈ψh, the equation (14) can be obtained.

そして、（１２）式の右荷重Ｗｒの項に、（１３）または（１４）式を代入することで、横断勾配ψｈが考慮された遠心力Ｆｃと変位量Ｈｃとの関係を表す関係式が得られる。さらに、その関係式の遠心力Ｆｃの項に、（８）式を代入することで、横加速度αと変位量Ｈｃが得られ、この関係式から補正量変換情報Ｇｈが生成される。補正量変換情報Ｇｈは、関係式そのものであってもよいし、関係式に基づいて生成されるテーブル情報であってもよい。

Then, by substituting the equation (13) or (14) into the term of the right load Wr in the equation (12), a relational expression expressing the relationship between the centrifugal force Fc and the displacement amount Hc in consideration of the transverse gradient ψh can be obtained. can get. Further, by substituting the equation (8) into the term of the centrifugal force Fc of the relational expression, the lateral acceleration α and the displacement amount Hc are obtained, and the correction amount conversion information Gh is generated from this relational expression. The correction amount conversion information Gh may be the relational expression itself or the table information generated based on the relational expression.

When turning to the right, the suspension of the right wheel changes so that the vehicle height becomes lower, so the correction amount is calculated as ΔH = Hc, that is, a value having a plus sign in order to offset the decrease. On the contrary, when turning to the left, the suspension of the right wheel changes so that the vehicle height becomes higher, so to offset the increase. The correction amount is calculated as ΔH = −Hc, that is, a value having a negative sign.

[6. measurement]
FIG. 10 shows a correction vehicle in which the detection value H is corrected by the error of the pitch angle θ calculated from the vehicle height detection value H when the vehicle is turning and the correction amount ΔH calculated by using the lateral acceleration α (and thus the centrifugal force Fc). It is a graph which showed the error of the pitch angle θ calculated from the high detection value H + ΔH. It can be seen that the detection error during turning is suppressed by reflecting the correction amount ΔH.

[7. effect]
According to the embodiment described in detail above, the following effects are obtained.
(7a) According to the information display system 1, an error occurs due to the correction amount ΔH calculated based on the lateral acceleration α (that is, the centrifugal force Fc) even while the vehicle is turning where an error occurs in the vehicle height detection value H. Therefore, the pitch angle θ of the vehicle can be accurately estimated from the vehicle height detection value H. As a result, the projected position of the AR image can be correctly corrected by the estimated pitch angle θ, and it is possible to suppress the occurrence of misalignment of the virtual image visually recognized by the driver with respect to the object.

(7b) In the information display system 1, since the influence of the cross gradient ψh is also taken into consideration when calculating the correction amount ΔH, an accurate correction amount ΔH can be obtained, and as a result, the pitch angle θ of the vehicle is θ. The calculation accuracy of can be further improved.

(7c) In the information display system 1, not only the vehicle pitch angle θ but also the projection position of the AR image is corrected according to the position of the driver's eyes, so that the position deviation of the virtual image visually recognized by the driver with respect to the object is accurate. It can be suppressed well.

[8. Other embodiments]
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and can be variously modified and implemented.

(8a) In the above embodiment, the case where the spring characteristic Kr of the suspension is constant when calculating the correction amount ΔH (that is, the displacement amount Hc) is shown, but the present disclosure is not limited to this. .. For example, if the spring characteristic Kr of the suspension differs between the contraction direction and the extension direction, the correction amount ΔH may be calculated by changing the spring characteristic Kr according to the direction of the acceleration α (that is, the centrifugal force Fc). good. In this case, the accuracy of calculating the correction amount ΔH can be further improved.

(8b) In the above embodiment, the seat sensor 33 and the trunk sensor 34 have been described in the case of detecting the presence / absence of a load, but may be configured to detect the weight of the load. In this case, the load state can be calculated more accurately, and the calculation accuracy of the vehicle pitch angle θ can be further improved.

(8c) The display control device 10 and methods thereof described in the present disclosure are provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. It may be realized by a dedicated computer. Alternatively, the display control device 10 and its method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the display control device 10 and its method described in the present disclosure comprises a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured by a combination. The computer program may also be stored on a computer-readable non-transitional tangible recording medium as an instruction executed by the computer. The method for realizing the functions of each part included in the display control device 10 does not necessarily include software, and all the functions may be realized by using one or a plurality of hardware.

(8d) A plurality of functions possessed by one component in the above embodiment may be realized by a plurality of components, or one function possessed by one component may be realized by a plurality of components. .. Further, a plurality of functions possessed by the plurality of components may be realized by one component, or one function realized by the plurality of components may be realized by one component. Further, a part of the configuration of the above embodiment may be omitted. Further, at least a part of the configuration of the above embodiment may be added or replaced with the configuration of the other above embodiment.

(8e) In addition to the above-mentioned display control device 10, a system having the display control device 10 as a component, a program for operating a computer as the display control device 10, a non-transitional non-transitional memory such as a semiconductor memory in which this program is recorded, etc. The present disclosure can also be realized in various forms such as an actual recording medium and a display control method.

1 ... Information display system, 2 ... Peripheral monitoring unit, 3 ... Behavior detection unit, 4 ... Driver detection unit, 5 ... Map storage unit, 6 ... Positioning unit, 7 ... Navigation device, 8 ... Characteristic storage unit, 9 ... HUD device 10, Display control device, 11 ... CPU, 12 ... Memory, 31 ... Height sensor, 32 ... Acceleration sensor, 33 ... Seat sensor, 34 ... Trunk sensor, 91 ... Projector, 92 ... Optical system, 101 ... Information generator, 102 ... correction processing unit, 110 ... instrument panel, 120 ... windshield, 121 ... projection area.

Claims (4)

The area in the front window of the vehicle on which the image to be recognized as a virtual image by the driver is projected is set as a projection area, and information on an object existing in the landscape visible to the driver is acquired through the projection area. An information generation unit (101) configured to set the projection position of the superimposed image superimposed on the object in the projection region according to the three-dimensional position information of the object.
A vehicle height acquisition unit (102: S140) configured to acquire a vehicle height detection value representing a displacement amount of the vehicle height of the vehicle, and a vehicle height acquisition unit (102: S140).
An acceleration acquisition unit (102: S150) configured to acquire lateral acceleration, which is an acceleration applied in the vehicle width direction of the vehicle, and
A characteristic storage unit (8) configured to store conversion information representing the correlation between the lateral acceleration and the displacement amount of the vehicle height detection value, and
The correction amount calculation unit (102) configured to calculate the correction amount of the vehicle height detection value by using the lateral acceleration acquired by the acceleration acquisition unit and the conversion information stored in the characteristic storage unit. : S160) and
Using the value obtained by correcting the vehicle height detection value acquired by the vehicle height acquisition unit with the correction amount calculated by the correction amount calculation unit, the pitch angle, which is the inclination angle of the vehicle in the front-rear direction, is calculated. A pitch angle calculation unit (102: S170) configured to calculate, and
An eye information acquisition unit (102: S180) configured to acquire eye information which is a detection result of an amount of deviation of the driver's eye position from a reference position, and an eye information acquisition unit (102: S180).
The projection position of the superimposed image set by the information generator is corrected according to both the pitch angle and the eye information so that the superimposed image visually recognized by the driver is superimposed and displayed on the object. The configured projection correction unit (102: S190) and
Display control device. The display control device according to claim 1.
Further, a load acquisition unit (102: S110) configured to acquire a load detection value which is a detection result of a load state applied to the vehicle at a plurality of measurement positions is further provided.
The pitch angle calculation unit is configured to change the conversion characteristic from the vehicle height detection value to the pitch angle of the vehicle according to the load detection value acquired by the load acquisition unit.
Display control device. The display control device according to claim 1 or 2.
Further comprising a gradient acquisition unit (102: S130) configured to acquire gradient information representing the gradient of the road on which the vehicle is traveling.
At least one of the correction amount calculation unit and the pitch angle calculation unit is a display control device configured to use the gradient information acquired by the gradient acquisition unit for the calculation of the correction amount or the pitch angle. The display control device according to any one of claims 1 to 3.
The correction amount calculation unit is a display control device configured to use the conversion information having different characteristics according to the direction of the acceleration acquired by the acceleration acquisition unit.

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