阅读说明：本技术 车载抬头显示虚像距离测量方法 (Vehicle-mounted head-up display virtual image distance measuring method ) 是由 刘显明 冉舒文 章鹏 雷小华 陈伟民 于 2020-05-20 设计创作，主要内容包括：本发明公开了车载抬头显示虚像距离测量方法,包括以下步骤：1)搭建虚像距离测量系统；2)调节相机在眼动范围内的位置,扫描并计算出虚像宽度W；3)调节相机在眼动范围内的位置,扫描并计算出虚像高度H；4)通过图像处理算法计算出虚像在图像中的宽p；5)计算出虚像在相机的感光元件上的大小P；6)利用相机成像的相似三角形关系,计算出虚像距离L；本发明利用相机本身的光轴,采取扫描的方式获取虚像的大小,从而将单目视觉测距的原理成功应用到虚像测量领域,基于常规单目测距的原理,解决了测量设备要求高的问题。(The invention discloses a vehicle-mounted head-up display virtual image distance measuring method, which comprises the following steps: 1) constructing a virtual image distance measuring system; 2) adjusting the position of the camera within the eye movement range, scanning and calculating the width W of the virtual image; 3) adjusting the position of the camera within the eye movement range, scanning and calculating the virtual image height H; 4) calculating the width p of the virtual image in the image through an image processing algorithm; 5) calculating the size P of the virtual image on a photosensitive element of the camera; 6) calculating a virtual image distance L by using a similar triangular relation imaged by a camera; the invention utilizes the optical axis of the camera and adopts a scanning mode to obtain the size of the virtual image, thereby successfully applying the principle of monocular vision distance measurement to the field of virtual image measurement.)

1. The vehicle-mounted head-up display virtual image distance measuring method is characterized by comprising the following steps:

1) constructing a virtual image distance measuring system; the virtual image distance measuring system comprises the head-up display (1), a camera (2), a reference plate (3) and a terminal;

the head-up display (1) is arranged below an automobile windshield (4); the camera (2) is arranged in the eye movement range of the driver through a three-dimensional displacement support; the reference plate (3) is arranged in front of the windscreen (4); the terminal is connected with a camera (2); the terminal can process and calculate the image shot by the camera (2) in real time;

2) adjusting the position of the camera (2) in the eye movement range, scanning and calculating the virtual image width W;

3) adjusting the position of the camera (2) in the eye movement range, scanning and calculating the virtual image height H;

4) calculating the width Q of the virtual image in the image through an image processing algorithm;

5) calculating the size P of the virtual image on the photosensitive element of the camera (2):

in the formula (1), a is a resolution parameter in the direction of the virtual image width Q in the camera (2). m is a size parameter of the photosensitive element in the direction of the virtual image width Q in the camera (2);

6) and calculating the virtual image distance L by using the similar triangular relation imaged by the camera (2):

in the formula (1), f is the focal length of the camera (2).

2. The method for measuring the distance between the virtual images of the vehicle-mounted head-up display according to claim 2, wherein in the step 2), the step of scanning and calculating the width W of the virtual image comprises the following steps:

2.1) adjusting the position of the camera (2) within the eye movement range such that the left edge of the virtual image is located in the center of the picture taken by the camera (2); recording the position S of the camera (2)₁And the position P of the left edge of the virtual image projected on the reference plate (3)₁；

2.2) moving the camera along the width direction of the virtual image to ensure that the optical axis of the camera (2) does not deflect;

2.3) observing the captured image in the terminal, stopping moving the camera (2) when the right edge of the virtual image is positioned at the center of the picture captured by the camera (2), and recording the position S of the camera (2)₂And the position P of the projection of the virtual image right edge on the reference plate (3)₂；

2.4) calculating the distance W, W ═ S, of the camera (2) moving in the virtual image width direction₂-S₁＝P₂-P₁。

3. The method for measuring the distance between the virtual images of the vehicle-mounted head-up display according to claim 1, wherein in the step 3), the step of scanning and calculating the height H of the virtual image comprises the following steps:

3.1) adjusting the position of the camera (2) within the eye movement range such that the upper edge of the virtual image is located in the center of the picture taken by the camera. Recording camera (2) position S₃And the position P of the projection of the virtual image upper edge on the reference plate (3)₃；

3.2) moving the camera along the virtual image height direction to ensure that the optical axis of the camera (2) does not deflect;

3.3) observing the captured image in the terminal, stopping moving the camera (2) when the lower edge of the virtual image is positioned at the center of the picture captured by the camera (2), and recording the position S of the camera (2)₄And the position P of the projection of the virtual image lower edge on the reference plate (3)₄；

3.4) calculating the distance H of the camera (2) moving along the height direction of the virtual image, wherein H is S₄-S₃＝P₄-P₃。

4. The method for measuring the distance between the virtual images of the vehicle-mounted head-up display according to claim 1, wherein: the reference plate (3) is provided with scales and marks.

Technical Field

The invention belongs to the field of head-up display virtual image measurement, and particularly relates to a vehicle-mounted head-up display virtual image distance measurement method.

Background

The effect of on-vehicle new line Display technique (HUD, Head Up Display) lies in driving information projection with driving in-process in driver field of vision scope, through special reflecting screen or windshield, will reflect the people's eye from the image light that the image source sent, forms the virtual image in driver field of vision the place ahead, the effect that image and external environment virtuality and reality combine. Head-up displays are a display device that displays virtual images, and measurement of the distance of the virtual image is important. The virtual image distance is the distance from the virtual image surface to the eye movement range plane of the driver, and directly reflects the spatial position of the virtual image, so that the display effect of the head-up display and the feeling of a user are directly influenced.

At present, in the field of head-up display measurement, measurement of HUD virtual image distance is mainly realized by a monocular defocus method principle and a binocular stereoscopic vision principle. The binocular stereo vision method utilizes the convergence angle of stereo lines to calculate the virtual image distance, and has high requirements for building a binocular system. The monocular defocusing method utilizes the object-image relation satisfied by the clear imaging of the camera to calculate the distance of the virtual image. When the method is used, the requirements on the accuracy of focusing and the accuracy of distinguishing the definition of the picture are high, and high-performance equipment is required to complete the method.

Disclosure of Invention

The invention aims to provide a vehicle-mounted head-up display virtual image distance measuring method, which can quickly and accurately realize the measurement of the size of a head-up display virtual image and the calculation of the virtual image distance. The technical scheme adopted for achieving the purpose of the invention is that the vehicle-mounted head-up display virtual image distance measuring method comprises the following steps:

1) and constructing a virtual image distance measuring system. The virtual image distance measuring system comprises a head-up display, a camera, a reference plate and a terminal.

The head-up display is arranged below a windshield of the automobile. The camera is arranged in the eye movement range of the driver through a three-dimensional displacement support. The reference plate is arranged in front of the windscreen. The terminal is connected with a camera. The terminal can process and calculate images shot by the camera in real time.

2) And adjusting the position of the camera in the eye movement range, and scanning and calculating the virtual image width W.

3) And adjusting the position of the camera in the eye movement range, and scanning and calculating the virtual image height H.

4) The width Q of the virtual image in the image is calculated by an image processing algorithm.

5) Calculate the size P of the virtual image on the photosensitive element of the camera:

in the formula (1), a is a resolution parameter in the direction of the virtual image width Q in the camera 2, and m is a size parameter of the photosensitive element in the direction of the virtual image width Q in the camera 2.

6) And calculating the virtual image distance L by utilizing the similar triangular relation of camera imaging:

in the formula (1), f is the focal length of the camera.

Further, in step 2), the step of scanning and calculating the virtual image width W includes the steps of:

2.1) adjusting the position of the camera within the eye movement range such that the left edge of the virtual image is located in the center of the picture taken by the camera. Recording the position S of the camera₁And the projection position P of the virtual image left edge on the reference plate₁。

2.2) moving the camera along the width direction of the virtual image to ensure that the optical axis of the camera does not deflect.

2.3) observing the captured image in the terminal, stopping moving the camera when the right edge of the virtual image is located at the center of the picture captured by the camera, and recording the position S of the camera₂And the projection position P of the virtual image right edge on the reference plate₂。

2.4) calculating the distance W that the camera moves in the virtual image width direction, W ═ S₂-S₁＝P₂-P₁。

Further, in step 3), the step of scanning and calculating the virtual image height H comprises the following steps:

3.1) adjusting the position of the camera within the eye movement range such that the upper edge of the virtual image is located at the camera shotThe center of the photograph. Recording camera position S₃And the position P of the projection of the virtual image upper edge on the reference plate₃。

3.2) moving the camera along the height direction of the virtual image to ensure that the optical axis of the camera does not deflect.

3.3) observing the captured image in the terminal, stopping moving the camera when the lower edge of the virtual image is located at the center of the picture captured by the camera, and recording the position S of the camera₄And the position P of the projection of the virtual image lower edge on the reference plate₄。

3.4) calculating the distance H, H ═ S that the camera moves in the direction of the height of the virtual image₄-S₃＝P₄-P₃。

Further, scales and marks are arranged on the reference plate.

The technical effect of the present invention is undoubtedly that the size of the measurement target needs to be known in advance in principle in the conventional monocular visual ranging, and the size of the virtual image cannot be measured by the conventional means due to the special property of the virtual image. The invention utilizes the optical axis of the camera and adopts a scanning mode to obtain the size of the virtual image, thereby successfully applying the principle of monocular visual ranging to the field of virtual image measurement. The invention is based on the principle of conventional monocular distance measurement, and solves the problem of high requirement on measuring equipment.

Drawings

FIG. 1 is a schematic diagram of a virtual image distance measurement system;

FIG. 2 is a schematic diagram of measuring virtual image width;

FIG. 3 is a schematic diagram of measuring virtual image height;

fig. 4 is a basic schematic diagram of virtual image distance measurement.

In the figure: a heads-up display 1, a camera 2, a reference plate 3 and a windscreen 4.

Detailed Description

The present invention is further illustrated by the following examples, but it should not be construed that the scope of the above-described subject matter is limited to the following examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.