GB/T 46926-2025Technical requirements and test methods for the field of vision assistance systems of light-duty vehicles (English PDF)

3.1 Forward field of vision

The driver's 180° forward field of vision through the transparent area of the front windshield glass and other glass surfaces (including side windows). […]

4.1 Area Division of Forward Field of Vision

4.1.1 The positions and ranges of area 1 and area 2 are shown in Figure 2 and Figure 3.

4.1.2 Area segmentation angle x, as shown in Figure 4, it is calculated in accordance with Formula (1).

Where, h---the height of the driver's eye point (DEP) from the ground, expressed in (m).

4.8 Information Format

In accordance with 6.1.4.1, carry out the test. The static information size of the system shall conform to the provisions of Table 2.

The unit system of the display information shall meet the requirements of GB 3100.

4.8.2 Information flickering

The flickering frequency of copied information shall be consistent with that of the source information. The flickering frequency of non-copied information shall be tested in accordance with 6.1.4.2, and should ideally be 60 ~ 120 times/min.

NOTE: information flickering refers to the cyclical phenomenon of the same type of display information appearing and disappearing in the same location, repeating completely at least twice.

4.9 Eyebox Height Adjustment

Systems with an eyebox vertical dimension less than 120 mm shall have an eyebox height adjustment function.

5.1 Operating Temperature Range

In accordance with the method of 6.2.2, carry out the test. Within the range of -40 °C ~ 85 °C, the system display information shall be visible, without black screen, shutdown, or image abnormalities.

5.2 Resistance to Sunlight Backflow

In accordance with 6.2.3, carry out the test. During sunlight exposure, the system display information shall be visible, without black screen, shutdown, or image abnormalities. After returning to normal temperature, the system shall not have any visible appearance damage, and its functions shall be normal.

5.3 Noise

In accordance with 6.2.4, carry out the test. During system startup, shutdown and height adjustment, the noise shall be less than 40 dB(A).

5.4 Virtual Image Distance

In accordance with 6.2.5, carry out the test. The virtual image distance of the system shall not be less than 2 m.

5.5 Downward Angle of Visibility

In accordance with 6.2.6, carry out the test. The downward angle of visibility of the system shall not be less than 1°.

5.6 Left Angle of Visibility

In accordance with 6.2.7, carry out the test. The left angle of visibility of the system shall be within the range of -0.5° ~ 0.5°, preferably 0°.

5.7 Field of View

In accordance with 6.2.8, carry out the test. The horizontal field of view of the system shall not be less than 3.5°, and the vertical field of view shall not be less than 0.5°.

5.8 Eyebox Dimensions

In accordance with 6.2.9, carry out the test. The eyebox dimensions of the field of vision assistant system shall meet the following requirements:

a) If the eyebox height is adjustable, the horizontal dimension shall be no less than 120 mm, the vertical dimension shall be no less than 40 mm, and the height adjustment stroke range shall be no less than 80 mm;

b) If the eyebox height is not adjustable, the horizontal dimension and vertical dimension shall both be no less than 120 mm.

5.9 Ghosting

In accordance with 6.2.10, carry out the test. The horizontal and vertical ghosting of the system's virtual image shall not exceed 3'.

NOTE: ghosting refers to an additional image whose brightness ratio to the original image is greater than 10%.

5.10 Binocular Parallax

In accordance with 6.2.11, carry out the test. The horizontal average value of binocular parallax of the system's virtual image shall not exceed 10', and the vertical average value of binocular parallax shall not exceed 7.5'.

5.11 Distortion

In accordance with 6.2.12, carry out the test. The horizontal and vertical static distortion of the system's virtual image shall not exceed 5%, the horizontal dynamic distortion shall be less than 36', and the vertical dynamic distortion shall be less than 20'.

5.12 Rotation

In accordance with 6.2.13, carry out the test. The average values of the horizontal and vertical rotation angles of the system's virtual image shall be within the range of -2° ~ 2°.

5.13 Modulation Transfer Function

In accordance with 6.2.14, carry out the test. The minimum values of the horizontal and vertical modulation transfer functions of the system's virtual image shall not be less than 0.3.

5.14 Stray Light

In accordance with 6.2.15, carry out the test. The maximum brightness of stray light within the system's virtual image range shall be less than 1,500 cd/m².

5.15 Brightness

In accordance with 6.2.16, carry out the test. The white field brightness of the system's virtual image shall not be less than 10,000 cd/m².

5.16 Contrast Ratio

In accordance with 6.2.17, carry out the test. The contrast ratio of the system's virtual image shall not be less than 1,000:1.

5.17 Brightness Uniformity

In accordance with 6.2.18, carry out the test. The brightness uniformity of the system's virtual image shall not be less than 65%.

5.18 Color Gamut Coverage Rate

In accordance with 6.2.19, carry out the test. The color gamut coverage rate of the system's virtual image shall be less than 29%.

5.19 Augmented Reality Fit

For FVA systems with augmented reality function, carry out the test in accordance with 6.2.20.

The fit between the virtual image and the corresponding real scene in the augmented reality portion of the system is shown in C.1 of Appendix C.

NOTE: "augmented reality function" refers to the function of an FVA system whose imaging medium is the front windshield glass and which does not have its own imaging medium, projecting virtual images of navigation guidance, driving plans, safety warnings, etc., onto the driver's forward field of vision and superimposing and aligning them with the real environment in real time. […]