A study on the topology optimization of a multi-spectral camera for space-use under a self-weight loading is presented.
A multi-spectral camera for space-use experiences a degradation of optical image on the space, which can not be detected on the optical test bench on the earth. This is due to the vanishing gravitational force in the space.
An optical surface deformation of a primary mirror, which is a principal component of the camera system, under the self-weight loading is an important factor affecting the optical performance of the whole camera system.
In this study, topology optimization of the primary mirror of the camera is presented.
In the optimization procedure, a new objective function, a root mean square value of the normal components of the mirror surface displacement is used, and total mass of the primary mirror is constrained to be a certain value.
The sensitivities of the objective function and constraint are calculated by direct differentiation method. Optimization procedure is carried out by an optimality criterion method using the sensitivities of the objective function and the constraint, calculated by direct differentiation method.
Two simple numerical examples are treated for verification.
For the light-weight primary mirror design, a three dimensional model is treated. Results of the optimized design topology for the primary mirror with varying mass ratios are presented.
