| At present,the high-altitude UAV market has entered a blowout development,with a wide range of models and a wide range of applications.In China,the high-altitude ultra-low temperature environment causes the flight control computer inside the UAV and many basic airborne instruments and equipment to respond sluggishly,display blockage and other faults There is a lack of systematic research on the threat and the resulting hidden flight risks,and the flight safety guarantee needs to be improved.Based on this,this paper proposes a design of a high-altitude UAV temperature control system and completes the following work.（1）Node distribution flexibility and scalability based on temperature control system,the system design adopts a modular drawer architecture,and the temperature control node distribution in a single drawer can be flexibly set according to actual needs.F4 series based on ST company are built.The temperature control node hardware platform of the 32-bit microprocessor system on a chip has completed the algorithm control implementation of the main control unit,storage unit and other functional units.In the analysis and comparison of three different types of temperature sensors,thermocouple,thermal resistance and pyroelectric Based on the temperature measurement principle and material characteristics,the design of the temperature measurement unit was completed.Finally,the three-wire thermal resistance sensor Pt1000 based on high temperature resistant metal platinum with large temperature coefficient,strong durability and high linearity was selected as one of the rectifier bridge circuits.arm to measure.（2）According to the high-altitude and low-temperature working environment where the UAV is located,by analyzing the thermal-structure coupling characteristics of the heat transfer module in the Multiphysics coupling simulation software COMSOL Multiphysics,the design of the heat transfer interface with solid conduction heating as the heat transfer mechanism is selected.,based on the generalized heat transfer equation,the response mechanism of the system’s steady-state temperature field distribution under the specified boundary conditions is studied,and the thermal thin approximation is used as the theoretical basis for the key to the Ni-Cr alloy circuit thin layer in the flexible thin-film heating device.Part of the full three-dimensional model and the thermal thin approximate model under three different thicknesses of 0.02 mm,0.01 mm and 0.005 mm are compared and simulated,and the obtained exact solutions and approximate solutions obtained by thin film approximation are analyzed and discussed.The optimal design of the thickness of the flexible film heating layer provides a theoretical basis.（3）The selection and optimization of the heating scheme are the keys to evaluating the significance of the system engineering.The working process of the flexible film heating device of this system involves many physical processes such as current conduction,heat transfer and structural stress and strain caused by thermal expansion.In order to explain these phenomena and consider and grasp their key design factors,this paper uses the advanced numerical simulation software COMSOL Multiphysics to conduct an electric-thermal-stress field coupling simulation for the heat conduction problem of a three-layer domain flexible thin-film heating device.,heat transfer and stress deformation,and discuss various factors that affect heating efficiency.（4）Multi-channel temperature control test,manual heating test,automatic heating test and heating threshold modification test were carried out on the entire temperature control system including the flexible heating device through the high and low temperature rapid change test box,and the temperature control performance of the system was quantified analysis. |
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