Design Of Miniaturized Attitude Measurement Module Based On Data Fusion

Accurate measurement of model attitude of high-speed aircraft is one of the most critical basic technologies in ultra-low temperature wind tunnel experiments.In ultra-low temperature wind tunnel experiments,attitude information of various degrees of freedom can be obtained through accurate measurement of model attitude of high-speed aircraft,which is one of the indispensable technologies for analyzing aerodynamic characteristics of high-speed aircraft.However,the traditional attitude measurement system is difficult to meet the requirements of ultra-low temperature wind tunnel experiment due to its large volume,single function,low environmental protection level and high cost.Therefore,it is of great significance to design an attitude measurement module with high precision,strong environmental adaptability,complete function and miniaturization.Taking attitude measurement technology as the research object,this paper focused on miniaturized structure design,channel crosstalk suppression technology,ultra-low temperature protection system,inertial sensor data preprocessing algorithm and data fusion algorithm,and obtained the following research results:(1)Aiming at the problem that multiple sub-modules are installed in a narrow space,the design concept of cube metal structure and multi-layer vertical laminae is proposed to improve the space utilization rate and module stability of larger devices.The size test results show that the size of the module is only 118mm*93mm*145mm(width *height * depth),realizing the miniaturization design.(2)According to the requirements of wind tunnel attitude test of ultra-low temperature model,the module needs to adapt to the harsh environment such as high temperature difference,high humidity and severe vibration.A protection scheme of ultralow temperature double-layer protective shell + internal constant temperature control module is proposed,in which the integral separation PID algorithm is designed to solve the problem of large overshoot and even oscillation of internal constant temperature system caused by the instant jump of constant temperature point.The results of ultra-low temperature simulation experiment and high and low temperature experiment show that the module can work normally at-163℃～50℃ and can keep the internal temperature of the module near the set constant temperature point with the change of the external temperature.(3)In view of the influence of parasitic capacitance between adjacent wires or pins at the input end of multiple data acquisition channels,the parallel AD technology and high impedance wiring technology are proposed to realize the shielding isolation between channels and reduce EMI noise.The upper computer function test results show that the high precision and multi-channel data acquisition is realized.(4)In view of the accelerometer’s sensitivity to high-frequency vibration signals and gyroscope drift errors,data preprocessing algorithms of median filter and sliding average filter and extended Kalman filter data fusion algorithm based on quaternion are designed,which effectively improve the output signal quality of accelerometer and gyroscope and eliminate the influence of errors,and give full play to the maximum advantage of the sensor itself.The module has a good dynamic response and measurement accuracy,the static and dynamic measurement accuracy index test results show that the static measurement accuracy is less than 0.05°,the dynamic measurement accuracy is less than 0.1°,the high precision measurement is realized.In this paper,the hardware and software scheme of the miniaturized attitude measurement module is analyzed in detail,and the feasibility of the scheme is verified by the upper computer simulation software,and a reasonable test scheme is formulated to verify that the various functions and performance indicators of the module meet the design requirements and meet the actual use requirements of attitude measurement.