A method for designing a total optical field combination correction solar simulator

Abstract

The present application relates to a kind of overall design method of full light field combination correction solar simulator, it is related to optical equipment field, comprising the following steps:Ⅰ. Investigation test site, is limited by site layout, selected overall optical path is off-axis reflection type optical path;Ⅱ. Select multiple groups of light source, each group of light source is composed of xenon lamp and ellipsoidal condenser, multiple groups of light source are designed to be distributed on the spherical surface with integrator field lens center as the center;Ⅲ. Parameter design is carried out to field lens and superposition lens in integrator, to make superposition lens image and overlap field lens to the same position of illuminated surface;Ⅳ. Select collimating mirror by multiple mirrors splicing and form, and the position that each mirror should be at is calculated;V. By the calculated value obtained, the position and angle of each mirror are automatically controlled by controller, to make collimating mirror reach the reflection effect of large size spherical mirror, the present application has the advantages that remote large aperture uniform solar irradiation simulation can be realized.

Description

Technical Field

[0001] This invention relates to the field of optical equipment technology, and in particular to a method for the overall design of a solar simulator with combined optical field correction. Background Technology

[0002] A solar simulator can simulate the luminous characteristics of the real sun, used to simulate solar radiation in outer space. It can realistically reproduce the collimation, uniformity, and spectral characteristics of solar irradiance in the space environment within a ground-based laboratory. The solar simulator mainly consists of a light source, a concentrating mirror, an optical integrator, and a collimating mirror. The light source emits uniformly bright light, which passes through the concentrating mirror, then through the optical integrator, and finally exits as parallel light through the collimating mirror, thus simulating the sun at infinity.

[0003] Solar simulators typically employ off-axis collimated optical systems, achieving high uniformity of irradiation. Furthermore, the angle between the axis of symmetry of the irradiated object and the optical axis of the light source system eliminates irradiance errors caused by secondary and multiple reflections from the irradiated object's surface. However, due to limited space in the experimental site, the angle between the solar simulator's optical axis and the irradiated area is relatively small, and the distance between the irradiated area and the collimating mirror is much greater than the distance between the integrator and the collimating mirror. Existing solar simulators generally require the distances between the irradiated area and the collimating mirror to be comparable to those between the integrator and the collimating mirror. If the current overall design method for solar simulators is followed, the simulated solar irradiation diverges at the required auxiliary area location, making it impossible to achieve a collimated solar irradiation simulation.

[0004] Therefore, to address the above shortcomings, it is necessary to provide a general design method for a solar simulator with full light field combined correction. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] The technical problem to be solved by this invention is to address the issue that the original design method of the solar simulator cannot achieve uniform solar irradiation over long distances with a large aperture.

[0007] (II) Technical Solution

[0008] To address the aforementioned technical problems, this invention provides a method for the overall design of a full-field combined correction solar simulator, comprising the following steps:

[0009] I. Due to site layout limitations, the overall optical path was selected as an off-axis reflection optical path.

[0010] II. Multiple light sources are selected, each consisting of a xenon lamp and an ellipsoidal condenser lens. The multiple light sources are designed to be distributed on a sphere centered on the integrator field mirror.

[0011] III. Design the parameters of the field lens and the superimposed lens in the integrator so that the superimposed lens images the field lens and superimposes it onto the same position of the illuminated surface;

[0012] IV. A collimating mirror composed of multiple reflecting mirrors is selected, and it has the following characteristics:

[0013]

[0014] F bi =F+400(i-1)+d

[0015] in,

[0016] F ai Set the focal length for the mirror that is close to the integrator;

[0017] F bi Set the focal length for the mirror that is far from the integrator;

[0018] F is the focal length of the collimating lens under ideal conditions;

[0019] i is the column number of the reflectors;

[0020] d is the aperture of the reflecting mirror;

[0021] V. Based on the calculated values, the controller automatically controls the position and angle of each reflector so that the collimating mirror achieves the reflection effect of a large-size spherical mirror.

[0022] As a further explanation of the present invention, preferably, the reflecting surface of the inner wall of the ellipsoidal concentrator mirror satisfies the following:

[0023] y 2 =2R0x-(1-e 2 )x 2

[0024] Where y and x are both coordinate parameters;

[0025] R0 is the radius of curvature at the vertex of the curve;

[0026] e is the eccentricity of the ellipse.

[0027] As a further explanation of the present invention, preferably, the radius of curvature R0 at the vertex of the curve satisfies:

[0028]

[0029] Where f1 is the nearest point distance;

[0030] f2 is the distance to the far point.

[0031] As a further explanation of the present invention, preferably, the eccentricity e of the ellipse satisfies:

[0032]

[0033] Where f1 is the nearest point distance;

[0034] f2 is the distance to the far point.

[0035] As a further explanation of the present invention, preferably, the function M of the line connecting the focal point of the ellipsoidal condenser lens and the annular zone and the x-axis is... u satisfy:

[0036]

[0037] Where u is the angle between the line connecting the focal point of the ellipsoidal condenser and the annulus and the x-axis.

[0038] As a further explanation of the present invention, preferably, after calculating the focal length of the multiple reflectors, the hydraulic cylinder is extended and retracted by the controller according to the corresponding distance. After the hydraulic cylinder stops working, infrared single beams are used to irradiate the target layer by layer from the center of the collimating lens. By observing the position of the light spot on the target, if it deviates from the area marked by the target, the controller is manually remotely controlled to deflect the reflectors of that layer so that the position of the light spot falls on the target position.

[0039] As a further explanation of the present invention, preferably, the target is located between the collimating lens and the target area, and the target is coated with multiple sets of concentric rings, the width of which is not less than 10 mm.

[0040] (III) Beneficial Effects

[0041] The above-described technical solution of the present invention has the following advantages:

[0042] Based on the principle of optical imaging, this invention employs an off-axis collimating optical system. Each column of unit collimating mirrors is designed with the same focal length, while different columns of unit collimating mirrors have different focal lengths. As the distance between the unit collimating mirror and the integrator increases, the focal length of the corresponding column of unit collimating mirrors gradually increases, thus forming a collimating mirror with a progressive multifocal design. By optimizing aberrations through grouping and adjusting the focal length parameters, the irradiance uniformity can reach ±5% in the required irradiance area, achieving high-precision uniform solar irradiance simulation. Attached Figure Description

[0043] Figure 1 This is the optical path design diagram of the ellipsoidal focusing mirror of the present invention;

[0044] Figure 2 This is the optical path design diagram of the integrator of the present invention;

[0045] Figure 3 This is an assembly effect diagram of the collimating lens of the present invention;

[0046] Figure 4 This is a structural diagram of the monolithic reflector of the present invention;

[0047] Figure 5 This is a partial structural diagram of the framework of the present invention;

[0048] Figure 6 This is a diagram showing the installation structure of the monolithic reflector of the present invention.

[0049] In the diagram: 1. Frame; 11. Horizontal frame; 12. Diagonal frame; 13. Connector; 2. Base; 21. Weight reduction hole; 3. Hydraulic cylinder; 4. Reflector. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] A method for overall design of a solar simulator with combined optical field correction includes the following steps:

[0052] I. The test site was examined. Due to the limitations of the site layout, the overall optical path was selected as an off-axis reflection optical path.

[0053] II. Based on the overall optical path designed in Step I, determine the location of the light source. Since the large-aperture solar simulator requires a large number of light sources, multiple sets of light sources are selected to improve the system's energy utilization. Each set of light sources consists of a xenon lamp and an ellipsoidal concentrator, and these multiple sets of light sources are designed to be distributed on a sphere centered on the integrator field mirror.

[0054] like Figure 1 As shown in the figure, using the coordinate system shown and placing the ellipsoidal condenser within the coordinate system, the reflecting surface of the inner wall of the ellipsoidal condenser is represented as:

[0055] y 2 =2R0x-(1-e 2 )x 2

[0056] Both y and x are coordinate parameters;

[0057] R0 is the radius of curvature at the vertex of the curve, which satisfies:

[0058]

[0059] f1 is the nearest point distance;

[0060] f2 is the distance to the far point;

[0061] Let e ​​be the eccentricity of the ellipse, satisfying:

[0062]

[0063] The ellipsoidal condenser has an opening at its bottom, which serves both as a mounting point for the xenon lamp electrode and as a ventilation and heat dissipation point. Let the angle between the bottom opening and the axis of symmetry be U0, and the angle between the top port and the axis of symmetry be U. m Then the enclosure angle of the condenser lens can be:

[0064] U = U m -U0

[0065] Ellipsoidal condenser lenses employ a large containment angle, which allows for high energy utilization.

[0066] In the optical design of an ellipsoidal condenser, the imaging magnification and the defocusing of the xenon arc peak brightness point relative to the first focal point are two important parameters. Different annular bands of the ellipsoidal condenser produce different image magnifications relative to the first and second focal planes. Therefore, the function M of the angle between the line connecting the focal point and the annular band and the x-axis is... u satisfy:

[0067]

[0068] Where u is the angle between the line connecting the focal point of the ellipsoidal condenser and the annulus and the x-axis.

[0069] By combining the above calculation formula with the actual site conditions, a light source with high energy utilization can be obtained.

[0070] III. The integrator, located between the collimating lens and the light source, effectively improves the optical uniformity of the system illumination. The optical integrator consists of two lens arrays. The front lens array, located at the second focal plane of the condenser lens, acts as a field lens and images the condenser's exit pupil onto the corresponding rear lens array. The rear lens array images the corresponding front lens array and superimposes it onto the same position on the illuminated surface. For example... Figure 2 As shown, L1 is the field collimating lens, and L2 is the stacking lens. Because the field lens group symmetrically divides the irradiance distribution on the second focal plane of the condenser lens, the uniformity on each lens is significantly better than the uniformity on the entire second focal plane. When the images of all the lenses are stacked, the uniformity errors can compensate for each other, so the uniformity is best at the overlapping image plane.

[0071] IV. A collimating lens is an essential device for converting a diverging, uniform beam into near-parallel light. Ideally, the collimating lens should employ a quadratic parabolic surface. However, for large-aperture solar simulators, an excessively large collimating lens aperture is not only difficult to manufacture but also prohibitively expensive. Therefore, this invention employs... Figure 3 The collimating mirror shown is composed of multiple mirrors 4 spliced ​​together.

[0072] Combination Figures 4-6The collimator consists of a large annular frame 1 and several horizontal and diagonal supports 11, which are bolted together by the same connector 13 to form a mesh-like frame. This allows the collimator to have a large volume but low weight, facilitating assembly and transportation. Each mesh contains a base 2, which also has weight-reducing holes 21. Hydraulic cylinders 3 are mounted on the base 2, with one to four cylinders. When there is only one cylinder, its extension and retraction ends are fixed to the base 2 and the reflector 4, allowing the reflector 4 to move only in one direction. When there is more than one cylinder, the cylinders are hinged to both the base 2 and the reflector 4, allowing the reflector 4 to move only in one direction and also to offset, thus reducing the deviation from the ideal parabolic collimator, minimizing optical aberrations, and preventing deterioration of the irradiance uniformity simulated by the solar simulator.

[0073] Multiple mirrors 4 Figure 3 The arrangement is shown below. Let the diameter of the ideal collimating mirror be D. Considering the existing manufacturing conditions, each column is designed with 4 mirrors with an aperture of d = 0.5m. Then the number of columns satisfies:

[0074]

[0075] Assuming the focal length of the spherical mirror is F under ideal conditions, then the focal length of the collimating mirror in the center column unit is F.

[0076] Based on the fitting simulation analysis, considering the tilt angle of the collimating lens relative to the integrator in the off-axis optical path, and the difference in distance between the two sides of the central column and the integrator, the initial focal length interval of the side closer to the integrator is set to... A progressive focal length interval of 40mm is optimal. The initial focal length interval on the side farther from the integrator is set to... If the optimal progressive focal length interval is 400mm, then:

[0077]

[0078] F bi =F+400(i-1)+d

[0079] in,

[0080] F ai Set the focal length for the mirror that is close to the integrator;

[0081] F bi Set the focal length for the mirror that is far from the integrator;

[0082] F is the focal length of the collimating lens under ideal conditions;

[0083] i is the column number of mirror 4;

[0084] d is the aperture of mirror 4;

[0085] V. After calculating the focal length of the multiple reflectors 4, the hydraulic cylinders 3 are extended and retracted by the corresponding distance via the controller. After the hydraulic cylinders 3 stop working, a target is placed between the collimating mirror and the target area. The target is coated with multiple sets of concentric rings, each ring being at least 10mm wide. Infrared single beams are used to illuminate the target layer by layer from the center of the collimating mirror outwards, observing the position of the light spot. If the light spot deviates from the area marked by the target, the controller is manually operated to control the extension and retraction of each hydraulic cylinder 3, causing the reflectors 4 of that layer to deflect, so that the light spot falls on the target. This method allows multiple planar reflectors 4 to be combined into a collimating mirror that more closely approximates an ideal parabolic surface, reducing the angle between the solar simulator's optical axis and the irradiated area and avoiding stray light.

[0086] In summary, this invention, based on the principles of optical imaging, utilizes an off-axis collimating optical system. Because the collimating mirror and optical integrator are at an angle, and the distances between the collimating mirrors and the optical integrator differ in different columns, the resulting aberrations in the irradiated area also vary. Therefore, by grouping the collimating mirrors longitudinally into columns and employing a progressive multifocal design, aberration correction across the entire light field of the solar simulator can be achieved, resulting in high-precision, uniform solar irradiance. Specifically, each column of collimating mirrors is designed with the same focal length, while different columns have different focal lengths. As the distance between the collimating mirror and the integrator increases, the focal length of the collimating mirror in the corresponding column gradually increases, thus forming a progressive multifocal collimating mirror design. Grouping and optimizing aberrations, and adjusting the focal length parameters, can achieve an irradiance uniformity of ±5% in the required irradiated area, realizing high-precision, uniform solar irradiance simulation.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for overall design of a solar simulator with combined optical field correction, characterized in that: Includes the following steps, I. Due to site layout limitations, the overall optical path was selected as an off-axis reflection optical path. II. Multiple light sources are selected, each consisting of a xenon lamp and an ellipsoidal condenser lens. The multiple light sources are designed to be distributed on a sphere centered on the integrator field mirror. III. Design the parameters of the field lens and the superimposed lens in the integrator so that the superimposed lens images the field lens and superimposes it onto the same position of the illuminated surface; IV. A collimating mirror composed of multiple reflecting mirrors (4) is selected, and it has the following characteristics: F bi =F+400(i-1)+d in, F ai The focal length is set for the mirror (4) that is close to the integrator; F bi The focal length is set for the reflector (4) that is far from the integrator; F is the focal length of the collimating lens under ideal conditions; i is the column number of the reflector (4); d is the aperture of the reflecting mirror (4); V. Based on the calculated values, the controller automatically controls the position and angle of each reflector so that the collimating mirror achieves the reflection effect of a large-size spherical mirror.

2. The overall design method for a full-field combined correction solar simulator according to claim 1, characterized in that: The reflecting surface of the inner wall of the ellipsoidal concentrator mirror satisfies: y 2 =2R0x-(1-e 2 )x 2 Where y and x are both coordinate parameters; R0 is the radius of curvature at the vertex of the curve; e is the eccentricity of the ellipse.

3. The overall design method for a full-field combined correction solar simulator according to claim 2, characterized in that: The radius of curvature R0 at the vertex of the curve satisfies: Where f1 is the nearest point distance; f2 is the distance to the far point.

4. The overall design method for a full-field combined correction solar simulator according to claim 2, characterized in that: The eccentricity e of the ellipse satisfies: Where f1 is the nearest point distance; f2 is the distance to the far point.

5. The overall design method for a full-field combined correction solar simulator according to claim 2, characterized in that: M, a function of the angle between the line connecting the focal point and the annulus of the ellipsoidal condenser and the x-axis. u satisfy: Where u is the angle between the line connecting the focal point of the ellipsoidal condenser and the annulus and the x-axis.

6. The overall design method for a full-field combined correction solar simulator according to claim 1, characterized in that: After calculating the focal length of the multiple reflectors (4), the hydraulic cylinder (3) is extended and retracted by the controller. After the hydraulic cylinder (3) stops working, infrared single beams are used to irradiate the target layer by layer from the center of the collimating lens. If the position of the light spot on the target is observed, and it deviates from the area marked by the target, the controller is manually remotely controlled to deflect the reflectors (4) of that layer so that the position of the light spot falls on the target.

7. The overall design method for a full-field combined correction solar simulator according to claim 6, characterized in that: The target is located between the collimating lens and the target area. The target is coated with multiple sets of concentric rings, and the width of the rings is not less than 10mm.

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