Optimal design and manufacturing of infrared surveillance camera mirror

This paper presents the numerical and experimental analysis to develop the 200mm diameter infrared surveillance camera aspheric reflector mirror. Recently, infrared camera has been developed for the powerful role in the field of astronomy, aerospace and military. By combining current state of art design and manufacturing technology, infrared camera is improving significantly to the lightweight, thermally stable, high accuracy, low volume, low cost, multi-spec. and multi-object purposes. To machine the aluminum based infrared camera reflector mirror the single point diamond turning (SPDT) process has been applied in this study. Aluminum workpiece can be deflected because of thin walled structure to obtain the lightweight structure. Finite element analysis was applied to investigate major deformations of workpiece material including centrifugal force effect due to angular velocity change. Design optimization using Simulated Annealing method has been performed to optimize the design variables of camera reflector mirror to reduce mirror deformation and weight. We obtain the 7.5% reduced deformation and 10% weight reduction of reflector mirror. Finally, this study can create successful possibility for the fabrication of aluminum, lightweight, precise infrared camera reflector mirror with a surface form error within a peak-to-valley error as little as 1/2 wavelength and a finish characterized by a surface roughness of 5nm Ra.