Research On Key Technologies Of Real-time Measurement Of Aircraft Fuel Quantity

With the development of the aviation industry,the fuel capacity of modern aircraft is increasing,and the importance of fuel measurement system is becoming increasingly prominent.The measurement of the aircraft fuel quantity has a direct impact on the flight safety of the aircraft.Accurately grasping the fuel quantity helps the pilot to formulate and adjust the flight plan in a timely manner.The development of modern aviation industry puts forward higher requirements for the accurate measurement of fuel quantity,and the aircraft fuel quantity measurement system is developing in the direction of digitization.The shape of the aircraft fuel tank is irregular,and the change of flight attitude will cause the measurement attitude error,which brings great difficulty to the accurate measurement of the fuel volume.For the measurement of the fuel volume of an aircraft fuel tank,a fuel volume characteristic data table of the fuel tank needs to be established first,and then the fuel liquid level height and the flight attitude angle measured by the sensor are combined to calculate the fuel volume.The single liquid level sensor measurement method has a large measurement dead zone,and the fuel level cannot be measured in the case of low fuel volume,and the range of the measurement dead zone increases with the increase of the flight attitude angle,which seriously affects the accuracy and reliability of the fuel volume measurement.In addition,the traditional slice-and-stack method for calculating the fuel volume characteristics is cumbersome and requires a large amount of calculation.In response to the above problems,This subject studies the key technologies of real-time measurement of aircraft fuel quantity,and analyzes the sensor layout,formulated a multi-sensor acquisition scheme,eliminated measurement dead zone,and aided the development of SolidWorks to achieve fast and accurate calculation of fuel volume characteristic data.On this basis,a multi-sensor aircraft fuel measurement system based on STM32 is designed to achieve accurate measurement of fuel volume,and builds an experimental platform to design experiments to verify the system performance.The main research contents are as follows:This paper first introduces the key technology of aircraft fuel measurement,and expounds the overall scheme of the fuel quantity measurement system,and on the basis of a comprehensive analysis of attitude error,a multi-sensor acquisition scheme is formulated.The principle of calculating fuel volume characteristic data by slice superposition method is expounded.The solid modeling and volume characteristic calculation functions of SolidWorks are used to simulate the fuel volume characteristic data.The principle of three-dimensional interpolation calculation of fuel quantity is introduced.Then,the design of the aircraft fuel quantity measurement system was completed,which was mainly divided into two parts:hardware circuit design and software development.The hardware circuit uses STM32H743IIT6 as the main control chip,and designs the main control module,signal acquisition module,power module,display module,storage module and so on.The software development used C language to develop STM32 fuel quantity measurement software,including data acquisition and conversion,data query,three-dimensional interpolation calculation of fuel quantity,LCD display and so on.Based on VB,SolidWorks was re-developed,and the software for automatically generating fuel volume characteristics was compiled to obtain the fuel volume characteristics data table.Finally,an experimental platform was built to design experiments to verify the performance of the measurement system,including the zero correction of the liquid level sensor,the horizontal liquid level fuel quantity measurement experiment and the fuel quantity measurement experiment under flight attitude,and analyze the experimental data,confirm that the relative error of the measurement system at the horizontal liquid level does not exceed 1%,and the relative error at the flying attitude does not exceed 3%,which meets the design requirements,and realize the real-time measurement of the fuel volume.