Background
Space cameras are one means by which people gather data. With the increasing demand of people for weather, resources, environment, military reconnaissance and astronomical observation, the design requirements of space cameras are also increasing continuously. Space cameras consist of multiple systems, of which the optical system is the most important component of a space camera. The optical system is composed of a plurality of reflecting mirrors, a projection mirror and a related supporting structure. Due to the special working environment of the space camera, the change of gravity from the ground to the space and the change of temperature in the system can generate great influence on the surface shape of the mirror surface. Therefore, in the design process, the surface shape change of the mirror and the related supporting structure under the conditions of the existence of gravity and the temperature change needs to be considered and calculated carefully.
At present, for a set of mirrors and supports, the process of designing the mirror surface shape is as follows: and modeling by using three-dimensional software, then carrying out finite element analysis, then exporting the result of the finite element analysis, calculating by using special mirror surface shape fitting software, and obtaining a surface shape result file, which is a complete operation process. In the actual design process, six combined working conditions of the gravity in the positive direction and the negative direction of the optical axis and three temperature values of normal temperature, temperature rise and temperature drop need to be considered at least in one analysis, eighteen combined working conditions of the gravity in the six directions of the three coordinate axes and three temperature values of normal temperature, temperature rise and temperature drop need to be considered at most, in addition, working conditions in other special gravity directions need to be calculated, and the number of times of repeated operation is more. In the design stage, the strict optical precision requirement makes the whole design process need to be calculated and optimized iteratively for many times. The traditional design analysis method is too slow in efficiency, analysis results need to be stored respectively in the multi-working-condition analysis and surface shape fitting processes, computer hardware resources are occupied, repeated and inefficient operation is easy to carry out misoperation on data or files, and wrong results are obtained.
Therefore, it is necessary to optimize the process of simulation and surface shape fitting.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a novel optical mirror surface shape calculation method for solving the problems of low efficiency and large occupied hardware resources of the traditional mirror surface shape design method.
The invention provides a method for calculating the surface shape of an optical mirror surface, which comprises the following steps:
s1, establishing a three-dimensional model of the optical lens group;
s2, carrying out mesh division and displacement constraint on the three-dimensional model through finite element analysis software;
s3, carrying out finite element simulation calculation on each mirror surface in the optical mirror group under various load working conditions to obtain surface shape node coordinates and surface shape node displacement values of the mirror surface under each load working condition, and outputting a plurality of independent simulation result files meeting the surface shape calculation requirements;
s4, performing fitting calculation on the surface shapes of the mirror surfaces in the simulation result files to obtain a plurality of surface shape results;
and S5, sorting the surface shape results and outputting a result file.
The invention can obtain the following technical effects:
under the condition of not modifying and influencing original software, the calculation of a plurality of load working conditions of a three-dimensional model can be completed, the displacement value of a surface shape node of each load step is output, surface shape fitting software is automatically called to complete the calculation of a plurality of load step surface shapes, and then result finishing software is called to finish and output the surface shape results into a file, so that the automation of mirror surface design work is realized, the work efficiency of single design simulation calculation and result subsequent processing is improved, the energy and time consumption of designers in low-efficiency work is reduced, and the errors caused by repeated complex operation in work are reduced.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.
Referring to fig. 1, an embodiment of the present invention provides a method for calculating an optical mirror surface shape, including the following steps:
step 1, establishing a three-dimensional model of the optical lens group.
And establishing a three-dimensional model of the optical lens group through three-dimensional software. The invention does not limit the three-dimensional software, and can use any three-dimensional software to realize the three-dimensional modeling of the optical lens group.
And 2, carrying out mesh division and displacement constraint on the three-dimensional model through finite element analysis software.
After the three-dimensional model of the optical lens group is built, the three-dimensional model is guided into finite element analysis software to give material properties, so that finite element meshing can be carried out on the three-dimensional model, and displacement is restrained.
The invention adopts ANSYS finite element analysis software which can be developed secondarily to carry out meshing and displacement constraint on the three-dimensional model, and also can adopt other finite element analysis software which can be developed secondarily to carry out meshing and displacement constraint on the three-dimensional model.
And 3, carrying out finite element simulation calculation on each mirror surface in the optical mirror group under various load working conditions to obtain surface shape node coordinates and surface shape node displacement values of the mirror surface under each load working condition, and outputting a plurality of independent simulation result files meeting the surface shape calculation requirements.
Because the finite element analysis software adopted by the invention can be developed secondarily, the calculation of the multi-load step of the optical lens group can be realized by a method of carrying out secondary development on the finite element analysis software. For example: and automatically completing finite element simulation calculation of the mirror surface under various load working conditions by calling the compiled secondary development file containing the gravity and temperature values under various working conditions.
The surface shape fitting can only fit one load working condition at one time, namely the surface shape node coordinates of the mirror surface and the corresponding surface shape node displacement value under the condition of one load working condition are read once, and the corresponding fitting result is output. Therefore, the secondary development method is to output the surface shape node coordinates and the surface shape node displacement values under various load working conditions to form a single independent simulation result file, and then fit the simulation result files one by one.
Because the surface shape fitting calculation needs to be performed on the simulation result file subsequently, the simulation result file needs to be output into a specified format meeting the input requirement of the surface shape fitting calculation.
And 4, performing fitting calculation on the surface shapes of the mirror surfaces in the simulation result files to obtain a plurality of surface shape results.
The invention automatically processes the simulation result file under each load working condition one by calling an external program.
For example: and calling surface shape fitting software to automatically perform fitting calculation on the surface shape of the mirror surface under the corresponding load working condition in each simulation result file, and finally obtaining a plurality of surface shape results, wherein each surface shape result corresponds to one load working condition of the mirror surface.
And 5, sorting the surface shape results and outputting a result file.
The invention automatically arranges the surface shape result obtained by multiple fitting in a mode of calling an external program. For example: and calling result sorting software to automatically sort the plurality of surface shape results and output the surface shape results into a result file, wherein the result file stores the plurality of mirror surfaces under the load working conditions.
The traditional method can only store the mirror surface of each load working condition independently, namely one load working condition of one mirror surface is stored as one surface shape result, which can occupy a large amount of hardware resources of a computer.
Under the condition that original software is not modified and influenced, the calculation of a plurality of load working conditions of a three-dimensional model is completed by calling a secondary development file, the displacement value of a surface shape node of each load step is output, calculation of a plurality of load step surface shapes is automatically completed by calling surface shape fitting software, and finally result sorting software is called to sort the surface shape results into a file to be output, so that the automation of mirror surface design work is realized, the work efficiency of single design simulation calculation and result subsequent processing is improved, the energy and time consumption of designers in low-efficiency work is reduced, and errors caused by repeated complex operation in work are reduced.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.