Opto-mechanical temperature adaptability analysis of a dual-band IRSP for HWIL simulation

The mid-wave and long-wave dual-band infrared scene projector (IRSP) is a practical instrument to test various infrared imaging systems in the experiment of hard-ware-in-the-loop (HWIL) simulation. It comprises two illumination modules and a telecentric projection module with dual field of view, covering atmospheric bands from 3.7 mu m to 4.8 mu m and 8 mu m to 12 mu m. In order to prevent the influence of temperature changes on the quality of projected images, the appropriate operating temperature range should be predicted during the development and design stages. In this paper, the integrated design of optical components is proposed, focusing on improving the temperature adaptability. Taking into account the different thermal environments faced by the illumination and the projection modules, opto-thermal analyses are carried out using finite element analysis (FEA) models respectively. According to the conditions of heat transfer, temperature field and the corresponding displacement field are calculated based on the quasi-static-processing approach. The least squares algorithm is adopted to fit the thermally induced deformation data for determining the Zernike polynomials of each lens's surface. And the optical performance of the IRSP is evaluated with the help of a ray-tracing software. The numerical simulations and the laboratory testing results show that the IRSP has good temperature adaptability in the temperature range from 10 degrees C to 35 degrees C.