Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations

Abstract

The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1–5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

Control of Optoelectronic Scanning and Tracking Seeker by Means the LQR Modified Method with the Input Signal Estimated Using of the Extended Kalman Filter

“…The accurate angle measurement of the detected object has a significant impact on the accuracy of its tracking [38][39][40][41][42]. In order to correctly determine the angular position of the detected object, it should be determined the law of airspace scanning by the optoelectronic system.…”

Autonomous Navigation of Unmanned Aircraft Using Space Target LOS Measurements and QLEKF

“…Recently, unmanned aircrafts flying at altitudes ranging from 20-100 km above sea level have received increasing interest in both the aeronautic and astronautic fields with respect to various applications [1][2][3]. As one of the key technologies of unmanned aircrafts, the precise navigation technique is essential for ensuring the feasibility and efficiency of the onboard guidance and control system [4][5][6].…”

Passive Athermal Optical Design Method Considering Thermal-Induced Surface Deformation

“…To avoid these disadvantages, passive athermalization ensures that an optical system without an additional focusing mechanism still provides clear image quality over an entire operating temperature range. This design method is used in optical systems with wide operating temperature ranges, such as large relative aperture photographic objective lenses, aerial drone lenses, projection optical systems, etc., [3][4][5]. Conventional passive athermal design is completed by glass material selection and optical-mechanicalthermal-integrated analysis [6,7].…”