阅读说明：本技术 一种用于十字路口照明的自由曲面透镜设计方法 (Design method of free-form surface lens for crossroad illumination ) 是由 曾茂庭 楼俊 高同瑞 于 2021-05-31 设计创作，主要内容包括：本发明公开了一种针对中小型十字路口照明的自由曲面透镜设计方法。包括(1)LED光源(2)自由曲面透镜(3)照明目标面。所述光源发出的光束经过所述自由曲面透镜在一照明目标面上形成十字光斑,能有效实现十字路口交通的夜间照明且能够节约能源和成本。(The invention discloses a free-form surface lens design method for lighting of small and medium-sized crossroads. The LED illumination device comprises (1) an LED light source (2) and a free-form surface lens (3) for illuminating a target surface. The light beam emitted by the light source passes through the free-form surface lens to form a cross light spot on an illumination target surface, so that night illumination of crossroad traffic can be effectively realized, and energy and cost can be saved.)

1. A free-form surface lens design method for crossroad illumination is characterized by comprising (1) an LED light source (2) and a free-form surface lens (3) for illuminating a target surface.

2. The method of claim 1, wherein the free-form surface lens design comprises: the LED light source enters the free-form surface lens, and a cross-shaped light spot can be formed on the illumination target surface.

3. The method of claim 1, wherein the method comprises the steps of:

step one, establishing a one-to-one corresponding energy mapping relation between a light source and a target surface by using a polar coordinate system, dividing the illumination light source and the target surface, and firstly, respectively arranging the light source at theta and the target surfaceThe division is carried out in the direction of M multiplied by N, and the division is carried out on the target surface under the polar coordinate according to the division mode of the light source, and the division is also carried out in the direction of M multiplied by N.

Step two, the energy mapping relation is expressed by a formula through an energy conservation law as follows:

wherein I (theta) is the intensity distribution of light emitted from the light sourceAnd theta is the light emitting angle of the light source,is the azimuth angle, omega, of the light emitted by the light source_sIs the solid angle of the light source, omega_TFor the illuminated object plane, ρ represents the length of the polar diameter of the object plane, γ represents the polar angle corresponding to the polar diameter, and Q (ρ, γ) represents the illuminance distribution on the polar object plane.

Step three, dividing the illumination light source according to the law of conservation of energyAnd a separation variable in the theta direction, and the light source is decomposed into M × N parts, each part containing equal luminous flux, which is specifically expressed as follows:

in the formula, theta_maxIs the maximum exit angle of the light source, theta_minIs the minimum exit angle of the light source,the maximum azimuth angle of the light source is,for minimum azimuth angle of light source, first pairDividing the direction, dividing the theta direction,represents the n +1 radial angle in the m +1 azimuth angle，Indicating the nth azimuth.

Step four, dividing the target surface, and only considering the gamma angle according to the axial symmetry of the target surface The design of the curved surface is that the whole angle is designed through axial symmetry, and the graph of the polar coordinate meets the formula; rho_sc＝f(γ)。

And step five, constructing a curved surface design in the first quadrant for the cross-shaped light spots due to the axisymmetric pattern, and then finishing the design of all the free-form surface lenses by utilizing a mirror image command.

And step six, the first quadrant of the target surface can be divided into four parts which can be regarded as being composed of four straight lines.

Step seven, assuming that the road width is 10m, therefore the four curves can be written as follows from bottom to top in sequence according to the formula:

the first straight line is:

the value range of gamma is (0, acrtan1/2), rho_sc1Is a first straight line from bottom to top;

the second straight line is:

the value range of gamma is (acrtan1/2, pi/4), rho_sc2Is a second straight line from bottom to top;

the third straight line is:

the value range of gamma is (pi/4, arctan2), and rho_sc3The third straight line from bottom to top;

the fourth straight line is:

the value range of gamma is (arctan2, pi/2), rho_sc4Is the fourth straight line from bottom to top.

And step eight, after the expression of the curve of the cross lens in the first quadrant is completed, establishing to complete the division of the grid, and gradually calculating the coordinates of each point of the cross light spot point by point according to the Snell law and the knowledge of space geometry. Snell's law is as follows:

n₁ sinθ₁＝n₂ sinθ₂

in the formula (I), the compound is shown in the specification,in the form of a vector of the incident light rays,in the form of a vector of the outgoing light rays,in the form of a vector of normal vectors,is a three-dimensional coordinate of the target surface, n₁And n₂Are the refractive indices of different media.

And ninthly, performing early noise reduction processing on the data before modeling, and avoiding the overlapping of data surfaces in the modeling process.

Tentatively modeling, correcting and simulating the simulation model.

And step eleven, finishing a free-form surface lens design method for lighting the crossroad.

Technical Field

The invention relates to an optical imaging and free-form surface imaging illumination system, in particular to a free-form surface illumination system which comprises an LED light source and a free-form surface lens, wherein light beams emitted by the LED light source pass through the free-form surface lens to form cross light spots on an illumination target surface.

Background

The free surface receives energy at a certain collimation angle on the target surface by accurately regulating and controlling light, so that uniform and stable irradiation distribution is formed, the energy utilization rate of a system can be improved, the complexity of the system can be reduced, and the portability of an instrument is improved. The free-form surface is a novel non-selective symmetrical optical surface type, has higher design freedom degree, and can control light transmission more accurately. In recent years, free-form surfaces have been widely applied to various advanced lighting system designs, resulting in better lighting effects and more compact system structures.

With the development of urbanization in China, town traffic draws more and more attention, and the most common night lighting condition of crossroads is a major key point of town traffic. The crossroad usually adopts the layout mode of arranging a plurality of 5-12 m middle-pole lamps or high-pole lamps to obtain the effects of wide illumination range and concentrated illumination, but meanwhile, the energy waste and the required cost are more.

Disclosure of Invention

The invention aims to solve the problems in the prior art and designs a free-form surface lens design method for lighting of small and medium-sized crossroads.

A free-form surface lens design method for crossroad illumination comprises an LED light source and a free-form surface lens, wherein light beams emitted by the LED light source pass through the free-form surface lens to form crosslight spots on an illumination target surface.

A free-form surface lens design method for crossroad illumination is realized by the following steps:

step one, establishing one-to-one corresponding energy mapping relation between a light source and a target surface by using a polar coordinate system, dividing the illumination light source and the target surface, and firstly, respectively using the light sourceAnd dividing the target surface into M × N parts in the theta direction, and dividing the target surface into M × N parts in polar coordinates according to the division manner of the light source.

Step two, the energy mapping relation is expressed by a formula through an energy conservation law as follows:

wherein I (theta) is the light intensity distribution emitted by the light source, theta is the light emitting angle of the light source,is the azimuth angle, omega, of the light emitted by the light source_sIs a solid angle of the light source,Ω_Tfor the illuminated object plane, ρ represents the length of the polar diameter of the object plane, γ represents the polar angle corresponding to the polar diameter, and Q (ρ, γ) represents the illuminance distribution on the polar object plane.

Step three, dividing the illumination light source according to the law of conservation of energyAnd a separation variable in the theta direction, and the light source is decomposed into M × N parts, each part containing equal luminous flux, which is specifically expressed as follows:

in the formula, theta_maxIs the maximum exit angle of the light source, theta_minIs the minimum exit angle of the light source,the maximum azimuth angle of the light source is,for minimum azimuth angle of light source, first pairDividing the direction, dividing the theta direction,denotes the (n + 1) th radial angle among the (m + 1) th azimuth angles,indicating the nth azimuth.

Step four, dividing the target surface, and only considering the gamma angle according to the axial symmetry of the target surfaceDesigning a curved surface, designing the whole angle through axial symmetry, and enabling the graph of the polar coordinate to meet a formula; rho_sc＝f(γ)。

And step five, constructing a curved surface design in the first quadrant for the cross-shaped light spots due to the axisymmetric pattern, and then finishing the design of all the free-form surface lenses by utilizing a mirror image command.

And step six, the first quadrant of the target surface can be divided into four parts which can be regarded as being composed of four straight lines.

Step seven, assuming that the road width is 10m, therefore the four curves can be written as follows from bottom to top in sequence according to the formula:

the first straight line is:

the value range of gamma is (0, acrtan1/2), rho_sc1Is a first straight line from bottom to top;

the second straight line is:

the value range of gamma is (acrtan1/2, pi/4), rho_sc2Is a second straight line from bottom to top;

the third straight line is:

the value range of gamma is (pi/4, arctan2), and rho_sc3The third straight line from bottom to top;

the fourth straight line is:

the value range of gamma is (arctan2, pi/2), rho_sc4Is the fourth straight line from bottom to top.

And step eight, after the expression of the curve of the cross lens in the first quadrant is completed, establishing to complete the division of the grid, and gradually calculating the coordinates of each point of the cross light spot point by point according to the Snell law and the knowledge of space geometry. Snell's law is as follows:

n₁ sinθ₁＝n₂ sinθ₂

in the formula (I), the compound is shown in the specification,in the form of a vector of the incident light rays,in the form of a vector of the outgoing light rays,in the form of a vector of normal vectors,is a three-dimensional coordinate of the target surface, n₁And n₂Are the refractive indices of different media.

And ninthly, performing early noise reduction processing on the data before modeling, and avoiding the overlapping of data surfaces in the modeling process.

Tentatively modeling, correcting and simulating the simulation model.

And step eleven, finishing a free-form surface lens design method for lighting the crossroad.

A design of a cross-shaped LED lighting free-form surface for small and medium-sized traffic intersections effectively realizes night lighting; the method can design the light spot with the target surface shape being the cross shape to be applied to the lighting of the crossroad.

Drawings

FIG. 1 is an overall schematic diagram of a free-form surface illumination optical system with cross-shaped light spots;

FIG. 2 is a schematic diagram of a grid division method under polar coordinates;

FIG. 3 is a schematic view of meshing of light sources in polar coordinates;

FIG. 4 is a schematic diagram of the preliminary division of a cross-shaped light spot;

FIG. 5 is a schematic view of a free-form surface lens with a cross-shaped light spot;

FIG. 6 is a schematic view of the distribution of illumination of a cross-shaped spot;

FIG. 7 is a schematic diagram of three-dimensional illuminance distribution and a profile curve of a cross-shaped light spot;

FIG. 8 is a schematic diagram of a free-form surface imaging illumination system with cross-shaped light spots;

Detailed Description

The embodiment is described with reference to fig. 1, and a method for designing a free-form surface lens for intersection illumination is implemented by the following steps:

step one, using a polar coordinate system, as shown in fig. 2, establishing a one-to-one corresponding energy mapping relationship between a light source and a target surface, and dividing the illumination light source and the target surface, firstly, respectively dividing the light sourceAnd dividing the target surface into M × N parts in the theta direction, and dividing the target surface into M × N parts in polar coordinates according to the division manner of the light source.

Step two, the energy mapping relation is expressed by a formula through an energy conservation law as follows:

in the formulaI (theta) is the light intensity distribution emitted by the light source, theta is the light emitting angle of the light source,is the azimuth angle, omega, of the light emitted by the light source_sIs the solid angle of the light source, omega_TFor the illuminated object plane, ρ represents the length of the polar diameter of the object plane, γ represents the polar angle corresponding to the polar diameter, and Q (ρ, γ) represents the illuminance distribution on the polar object plane.

Step three, as shown in fig. 3, the division of the illumination light source is according to the law of conservation of energy, and the sum of theta and theta of the light source isDirectionally separating the variable, and decomposing the light source into M × N parts, wherein the luminous flux contained in each part is equal, and the specific expression is as follows:

in the formula, theta_maxIs the maximum exit angle of the light source, theta_minIs the minimum exit angle of the light source,the maximum azimuth angle of the light source is,for minimum azimuth angle of light source, first pairDividing the direction, dividing the theta direction,denotes the (n + 1) th radial angle among the (m + 1) th azimuth angles,indicating the nth azimuth.

Step four, dividing the target surface, and only considering the gamma angle according to the axial symmetry of the target surfaceDesigning a curved surface, designing the whole angle through axial symmetry, and enabling the graph of the polar coordinate to meet a formula; rho_sc＝f(γ)。

And step five, constructing a curved surface design in the first quadrant for the cross-shaped light spots due to the axisymmetric pattern, and then finishing the design of all the free-form surface lenses by utilizing a mirror image command.

Step six, the first quadrant of the target surface can be divided into four parts, which can be regarded as being composed of four straight lines, as shown in fig. 4.

Step seven, assuming that the road width is 10m, therefore, the four curves from bottom to top (the first straight line ranges from a to b, the second straight line ranges from b to c, the third straight line ranges from c to d, and the fourth straight line ranges from d to e) can be written as follows according to the formula:

the first straight line is:

the value range of gamma is (0, acrtan1/2), rho_sc1Is a first straight line from bottom to top;

the second straight line is:

the value range of gamma is (acrtan1/2, pi/4), rho_sc2Is a second straight line from bottom to top;

the third straight line is:

the value range of gamma is (pi/4, arctan2), and rho_sc3The third straight line from bottom to top;

the fourth straight line is:

the value range of gamma is (arctan2, pi/2), rho_sc4Is the fourth straight line from bottom to top.

And step eight, after the expression of the curve of the cross lens in the first quadrant is completed, establishing to complete the division of the grid, and gradually calculating the coordinates of each point of the cross light spot point by point according to the Snell law and the knowledge of space geometry. Snell's law is as follows:

n₁ sinθ₁＝n₂ sinθ₂

in the formula (I), the compound is shown in the specification,in the form of a vector of the incident light rays,in the form of a vector of the outgoing light rays,in the form of a vector of normal vectors,is a three-dimensional coordinate of the target surface, n₁And n₂Are the refractive indices of different media.

And ninthly, performing early noise reduction processing on the data before modeling, and avoiding the overlapping of data surfaces in the modeling process.

Tentatively modeling, correcting and simulating the simulation model.

And step eleven, finishing a free-form surface lens design method for lighting the crossroad.