Research On High Precision Of Inertial Measuring Combination In Temperature Field Modeling And Optimization Design

The strapdown inertial navigation system is a navigation system capable of continuousoutput information such as position, velocity, and posture. The precision of inertial navigationis mainly decided by the inertial sensors. SINS has a high sensitivity to temperature,especially during the process of high altitude flight, SINS is prone to high temperature, thusgreatly affect the precision and working stability of the system. Therefore, to solve thestrapdown inertial navigation system’s thermal Dissipation is the necessary condition toguarantee the normal work of the system.This paper is based on the study of the heat source of the parts in SINS, design the wholemachine structure, carry out the temperature field modeling and thermal analysis to verify theaccuracy of the model by experiment, and optimize the design.First analyzes in detail about the cooling way of the SINS, and choose the best way ofcooling. Through the analysis of the temperature field of the SINS, according to thecharacteristics and requirements of each heat source, to design the interior structure. Inertialsensor has a high sensitivity to temperature, during the design process we need to make surethe surface contact with the shell as much as possible. To reduce the influence on the inertialsensor of other large heat source, need to isolate them. In the design process in addition toconsider the thermal design of each device, such as layout, installation, and under the requiredstiffness, we need to keep the quality of the SINS as small as possible.Secondly, the thermal analysis software of Icepak is adopted to design the SINS’stemperature field modeling and simulation analysis. Because of the SINS is a complexstructure, the thermal model of the SINS are simplified, equivalent, model transformationanalysis, the calculation of the thermal model were carried out on the Icepak software. Get thetemperature distribution chart of the SINS. The SINS’s surface temperature from38.9℃to42℃, the average temperature of the fiber optic gyrois43.5℃, it is result that thetemperature distribution of the SINS is uniform, small temperature difference between theshell and gyro.Designed of SINS through the non-contact and contact way to carried out thetemperature test on the prototype, compared the results with the simulation results to verifythe accuracy of thermal analysis model. In the guarantee of the accuracy of the model tooptimize the temperature field of the SINS design. Main optimization scheme is to change the installation surface of the fiber optic gyro, increase the contact area between the quartzflexible accelerometer and the intermediate housing, add thermal pad. Finally afteroptimization, the highest temperature of the SINS’s intermediate housingis40.98℃, with ageneral decrease6.22%. The highest temperature of the fiber optic gyro shell is42.52℃, witha general decrease5.64%.