Study On The Influence Mechanism Of Temperature Variation On Optical Parameters Of Star Sensor

Star sensors,as the most accurate attitude sensors at present,occupy an important position in the aerospace field.However,star sensors are usually faced with complex space temperature variation environment,which will cause the deformation of the optical system components of star sensors,and then lead to the variation of optical system parameters,and finally lead to the decline of imaging quality,reducing the navigation accuracy of star sensors.The existing research mainly focuses on the material of optical system through the thermal-free technology,but lacks the theoretical model research on the relationship between the temperature change and the optical parameters of star sensors.In this paper,the influence mechanism of temperature variation on the optical parameters of star sensors is taken as the research object.A satellite point drift model is established and a simulation experiment is carried out.The experiment provides data support for exploring the theoretical model relationship between temperature change and the optical parameters of star sensors.Focus on the imaging model around the star sensor;Semiconductor temperature acquisition and control system;Based on the imaging model,the satellite point coordinate drift model is developed and simulated.Finally,the model relationship between temperature variation and optical parameters of star sensor is verified by experiments.The main contents of this paper are as follows:(1)The current research status of temperature variation on the optical system of star sensor is expounded,and the significance of establishing the relationship between temperature change and the parameter model of the optical system is analyzed according to the influence of temperature variation at the present stage.(2)Principle of star sensor and structural design of temperature control system.The basic principle of celestial navigation,the principle of star sensor and the whole structure of temperature control system are introduced.(3)Theoretically analyze the influence of temperature variation on the optical parameters of the star sensor,introduce the imaging model of the star sensor,and deduce the star image point drift model according to the imaging model.(4)Based on the simulated isometric fixed satellite image,the simulation experiment on the influence of temperature variation on the optical parameters of the star sensor was studied.Through the satellite image point drift model,the mathematical model between the temperature variation and the internal parameters of the optical system based on BP neural network was established.(5)The experiment verifies the validity of the temperature variation and the internal parameter model of the optical system,which can effectively reduce the amount of image point drift after the influence of temperature.