CN108804729B

CN108804729B - Simple setting method for convex mirror flat mirror ratio and convex mirror convexity parameter of left and right rearview mirrors of automobile

Info

Publication number: CN108804729B
Application number: CN201710309997.2A
Authority: CN
Inventors: 王司宇
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-05-05
Filing date: 2017-05-05
Publication date: 2021-12-21
Anticipated expiration: 2037-05-05
Also published as: CN108804729A

Abstract

The invention discloses a simple setting method for flat mirror proportion and convex mirror convexity parameter of left and right rear-view mirrors of an automobile, based on the principle of a light projection method, on the premise of meeting national standard requirements, the total coverage range of the left rear-view mirror visual field as large as possible and the overlapping area of the plane mirror and the convex lens visual field as small as possible are realized by selecting two parameters of convex lens convexity and convex/flat mirror proportion. Specific optimized performance indicators are: 1. the total coverage of the left rearview mirror vision; 2. the overlapped area is covered by the visual fields of the plane mirror and the convex lens; 3. balancing the mixed weighting optimization indexes of the total coverage range of the left rearview mirror vision range as large as possible and the overlapping area of the flat mirror vision range and the convex lens vision range as small as possible. The method for setting and optimizing the proportion of the flat mirror and the convexity parameter of the convex mirror is simple, visual and feasible, and can give consideration to the advantages of the flat mirror and the convex mirror so as to achieve the existing large visual field range and improve the accuracy of distance judgment.

Description

Simple setting method for convex mirror flat mirror ratio and convex mirror convexity parameter of left and right rearview mirrors of automobile

Technical Field

The invention relates to the field of automobile safety, in particular to a simple and convenient method for setting the ratio of a convex mirror to a flat mirror and the convexity parameter of the convex mirror of a left rear-view mirror and a right rear-view mirror of an automobile.

Background

The existing mainstream rearview mirrors are divided into two categories, namely a plane mirror and a convex mirror. The plane mirror has the advantages that the rear-view object is free of distortion, the size and the actual distance of the rear-view object can be truly reflected, and the defect that the rear-view range and the viewing angle are small is caused. The convex mirror has the characteristics that the rear-view object is reduced, the rear-view range and the visual angle are expanded, but the size and the actual distance of the rear-view object cannot be truly reflected, and although a driver can be improved by a section of adaptive contrast process, the possibility of misjudgment still exists.

One technical development trend is to combine flat mirrors with convex mirrors, with flat mirrors being used on the inside and convex mirrors on the outside of the left and right rear-view mirrors. Therefore, the advantages of the plane mirror and the convex mirror can be taken into consideration, so that the existing large visual field range is achieved, and the accuracy of distance judgment is improved.

The national standard "performance and installation requirements of indirect visual field devices for motor vehicles (GB 15084-2013)" requires: the driver can see at least 4000 mm wide, bounded by a plane parallel to the vertical longitudinal middle plane of the vehicle and passing through the furthest point of the vehicle on the driver's side, and extending to a horizontal road surface portion 20000 mm behind the driver's eyepoint. At the same time, the driver should be able to see the road surface, starting from a point 4000 mm behind the vertical plane passing through the driver's eyes, 1000 mm wide, defined by a plane parallel to the vertical longitudinal middle plane of the vehicle and passing through the farthest point of the vehicle, as shown in fig. 1.

Disclosure of Invention

In view of the current situation that the proportion of the convex mirror proportion of the left and right rear-view mirrors of the automobile and the parameters of the convexity of the convex mirror are mainly set by experience at present, the invention aims to solve the technical problem of simple parameter setting of the proportion of the convex mirror proportion of the left and right rear-view mirrors of the automobile and the parameters of the convexity of the convex mirror by setting reasonable indexes and an optimization method.

Considering that the height of the automobile is not high in practical situation, the up-down rotation adjustment amplitude is not large compared with the left-right rotation adjustment amplitude when the rearview mirror is adjusted by an actual driver, the deviation of the far vision projected to the plane of the automobile body due to the difference of the vision height is small, and considering the design simplification requirement and convenience, the deviation is negligible, and the following expansion is based on the plane of the automobile body.

Based on the principle of the lamp projection method, it is assumed that a point light source E is placed at the position of the driver's eyes, as shown in fig. 2, where OB is L, OQ is R, and ratio is OA/OB. Taking the automobile left rearview mirror as an example, the farthest point of the mirror surface of the left rearview mirror is taken as an origin O, the advancing direction of the automobile body is taken as the positive direction of a Y coordinate axis, the advancing direction of the automobile body is perpendicular to the advancing direction of the automobile body, and the direction from the left rearview mirror to the right rearview mirror is taken as the positive direction of an X left rearview mirror. The XOY coordinate plane is established parallel to the plane of the vehicle body.

Let the left rearview mirror length OB ═ L; the included angle between the mirror surface and the OX axis is theta, the left OA of the left rearview mirror is a convex mirror, the right AB of the left rearview mirror is a plane mirror, and the convex/plane mirror ratio is OA/OB. The convexity of the convex mirror OA is R, i.e. satisfies:

(x-x_Q)²+(y-y_Q)²＝R²

for the plane mirror AB, the extent of the light beam at point E after it is directed to AB in the field of view of the left-hand mirror is determined by the coverage of the reflected light beams of the light beams EB and EA. And EB and EA reflect rays such that the angle of reflection is equal to the angle of incidence, with the normal to the mirror, and B's normal and EB's reflected rays are as shown in fig. 2.

For convex mirror OA, the extent of the light beam from point E, which is directed towards OA, in the field of view of the left-hand mirror is determined by the coverage of the reflected light beams from light beams EO and EA. The EO and EA reflected rays also satisfy the condition that the reflection angle is equal to the incident angle, except that the normal of the convex lens passes through the center of the convex lens, the normal of the O point is OQ ', and the EO reflected ray is OE', as shown in fig. 2. The angle calculation formula is as follows:

∠E″′OX＝θ+arccos(L*ratio/2/R)-∠EOQ′

in addition, the EA needs to additionally consider the position difference and the angle difference of 2 × arcsin (L × ratio/2/R) of the a point for the reflected light of the convex lens OA.

For the convexity of the convex mirror, the national standard stipulates that the R for the interior rear-view mirror and the class III main exterior rear-view mirror is not less than 1200 mm; the R of the class II main external rear-view mirror is not less than 1800 mm. And the degree of convexity also reflects the degree of image distortion. In view of the image distortion constraints, subsequent example verification will limit the convex mirror convexity to between 1-2 meters.

Thus, the light ray EA is reflected by two reflected light rays, one reflected by the plane mirror AB and the other reflected by the convex mirror OA. The closer the two reflected rays are, the higher the overlap of their coverage, and the less visual clutter is caused. The larger the range of coverage of the left-hand mirror with the reflected light rays EO and EB means that the driver can observe the larger the rear range. In addition, the reflected light of the EB is as close as possible to the left vehicle body to obtain an optimal observation range. These factors will be the focus of subsequent embodiment verification considerations. The system simulation flow chart is shown in fig. 3.

On the premise of meeting the national standard requirements, the total coverage range of the visual field of the left rearview mirror as large as possible and the overlapping area of the visual field of the plane mirror and the visual field of the convex lens as small as possible are realized by selecting two parameters of the convexity of the convex lens and the proportion of the convex/flat mirror. Obviously, the optimization performance indicators that can be selected are: the total coverage of the left rearview mirror vision and the overlapping area of the flat mirror vision and the convex lens vision.

How to balance two optimization indexes g (R, ratio) of the total coverage area f (R, ratio) of the left rearview mirror visual field as large as possible, the overlapping area of the planar mirror visual field and the convex lens visual field as small as possible, different weighting modes can be adopted, and the preferable optimization indexes can be selected as follows: the maximization weighting function Θ (R, ratio) ═ f (R, ratio) + λ/g (R, ratio), where λ is the adjustment weight. When the theta (R, ratio) is maximized, the adjustment weight λ needs to be selected based on the equal-proportion weight principle and adjusted appropriately and flexibly.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

Fig. 1 is a chinese-specified automobile rearview mirror standard (the shaded portion is the field of view) to which the present invention is referred.

In the figure: 1: the eye point of the driver.

FIG. 2 is a schematic diagram of simulation principles and related parameters of the present invention.

FIG. 3 is a block diagram of the system simulation process of the present invention.

Fig. 4 is a graph showing exemplary simulation results of the present invention under the parameters sita 0.33, R1.2, and ratio 1/3.

Fig. 5 is a diagram illustrating an example simulation result of the maximum optimization result of the total coverage area of the left rearview mirror (sita is 0.33, R is 1, and ratio is 0.25).

Fig. 6 is a diagram showing an example simulation result of minimization of the overlapping region of the field coverage of the plane mirror and the convex lens (sita is 0.33, R is 2, and ratio is 0.05).

Fig. 7 is a diagram illustrating example simulation results of the dual-index weighting function optimization results (sita 0.33, R1.08, and ratio 0.2).

Detailed Description

In the following, we will use the chevroleraceae pocky 2015 flagship version left rear view mirror as an example to illustrate the embodiment and the optimized design. The specific measurement parameters are as follows: the length L of the left rearview mirror is 0.182 m, and the coordinates of the eye point are (0.645 m and-0.54 m).

We choose the parameters as follows: the left mirror deflection angle θ is 0.33 radian, the convex lens convexity R is 1.2 meters, and the convex/flat mirror ratio is 1/3. And selecting a visual field observation section y of-20 meters according to national standards. The simulation results are shown in fig. 4. In the figure, a red dotted line "is a boundary reflected ray of the plane mirror AB, and a blue dotted line" is a boundary reflected ray of the convex lens OA, and the projection of the red dotted line at a position 20 m behind the convex lens OA shows that: the reflected light of EB is basically tightly attached to the extension line of the car body at the position 20 meters behind. But the obvious results are: the coverage of the left rearview mirror is general, and the overlapping area of the vision coverage of the plane mirror and the convex lens is large.

The maximum total coverage of the left rearview mirror vision and the minimum overlapping area of the plane mirror and the convex lens vision are realized by optimizing two parameters of the convex lens convexity and the convex/flat mirror ratio.

And optimizing the performance index to select the total coverage range of the visual field of the left rearview mirror. The result of optimizing only as much total coverage of the left-rear view mirror field of view as possible is: the convex lens convexity is 1 meter and the convex/flat mirror ratio is 0.25, and the simulation result is shown in fig. 5. The total coverage of the left rear view mirror field is 5.3050 m, and the overlapping area of the flat mirror and convex lens fields is 0.9299 m.

And optimizing the performance index, and selecting a plane mirror and convex lens view coverage overlapping area. The result of optimizing only as small an overlap area of the field of view of the flat and convex lenses as possible is: the convex lens convexity is 2 meters, the convex/flat mirror ratio is 0.05, and the simulation result is shown in fig. 6. The total coverage of the left rear view mirror field is 4.4372 m, and the overlapping area of the flat mirror and convex lens fields is 0.0948 m.

Θ(R，ratio)＝f(R，ratio)+λ/g(R，ratio)

The optimization performance index selects the maximization index weighting function, wherein lambda is the adjusting weight. When the weighting function Θ (R, ratio) is maximized, the adjustment weight λ is selected, according to the equal proportion weight principle, λ is selected to be 5.3050 × 0.0948 ═ 0.5029 ≈ 0.5, and the corresponding optimization result is: the convex lens convexity is 1.08 m, the convex/flat mirror ratio is 0.2, and the simulation result is shown in fig. 7. The total coverage of the left rear view mirror field is 5.0532 m, and the overlapping area of the flat mirror and convex lens fields is 0.6919 m.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A simple setting method for the convex mirror proportion and convex mirror convexity parameter of left and right rearview mirrors of an automobile is characterized in that the analysis and calculation are based on the unfolding of the plane of the automobile body, and the deviation of the projection of the far field of view to the plane of the automobile body caused by the difference of the heights of the fields of view is ignored; the total coverage range f (R, ratio) of the visual field of the left rearview mirror is as large as possible and the overlapping area g (R, ratio) of the visual field of the plane mirror and the convex lens is as small as possible by selecting two parameters of the convex lens convexity R and the convex/flat mirror ratio; the optimization indexes are as follows: a maximization weighting function Θ (R, ratio) ═ f (R, ratio) + λ/g (R, ratio), where λ is an adjustment weight; taking an equal proportion weight principle as a reference and properly and flexibly adjusting the weight lambda;

the method comprises the following steps:

step 1, setting simulation environment parameters and rearview mirror parameters;

step 2, judging whether the rearview mirror is in a visible range of 4 meters or not;

step 3, judging whether the position of the rearview mirror at 4 meters meets the condition that the vehicle body is visible for 1 meter;

step 4, adjusting the deflection angle of the left rearview mirror;

step 5, calculating the light spot coverage range of the rearview mirror at 4 meters;

step 6, judging whether the rearview mirror is in a visible range of 20 meters or not;

step 7, judging whether the position of the rearview mirror 20 meters meets the condition that the vehicle body is visible for 4 meters;

Step 8, adjusting the deflection angle of the left rearview mirror;

step 9, calculating the light spot coverage area at the position of 20 meters behind the rearview mirror;

step 10, judging whether the visual field width and the visual field overlapping degree of the flat mirror of the convex mirror are optimized;

and 11, outputting design parameters and graphic schematic results.

2. The simple setting method for the parameters of the flat mirror ratio and the convexity of the convex mirror of the left and right rearview mirrors of the automobile as claimed in claim 1 is characterized in that the specific optimized performance indexes are as follows: a. the total coverage of the left rearview mirror vision; b. the overlapped area is covered by the visual fields of the plane mirror and the convex lens; c. balancing the mixed weighting optimization indexes of the total coverage range of the left rearview mirror vision range as large as possible and the overlapping area of the flat mirror vision range and the convex lens vision range as small as possible.

3. The simple setting method for the flat mirror ratio and the convex mirror convexity parameter of the left and right rearview mirrors of the automobile as claimed in claim 2, characterized in that the optimization performance index is based on the equal proportion weight principle and is adjusted flexibly if the optimization performance index selects the maximization index weighting function.

4. The simple setting method for the proportion of the convex mirror and the convexity parameter of the left and right rearview mirrors of the automobile as claimed in claim 1, characterized in that the optimization of the proportion of the convex mirror and the convexity parameter of the convex mirror is iterative interactive verification optimization when one of the three optimization performance indexes is selected for implementation, and the method is convenient to operate and intuitive.