Development Of Measurement Apparatus For Determining The Mass And Centroid Of A Trail Cover

Mass and three axes of centroid are the major parameters for general design of an aircraft. Accurate measurement of mass & centroid plays an important role in enhancing the orbit accuracy, stabilizing the flight attitude, and promoting the capacity. The tail cover is located in the ending of aircraft which protects the internal complex structure from high temperature. Mass & centroid is related to the reliable separation of trail-hood, as well as playing an effect on the safety of the missile launcher and people, so it is indispensable that measuring the mass and three axes of centroid for an aircraft. According to the mass & centroid testing demands for a certain tail cover, this article put forward a project based on 3 point weighing method,and develops a set of automation equipment which measures mass & centroid of a certain tail cover.Analyzing the measurement equipments and measurement methods of mass ¢roid at home and abroad, The thesis make sure measuring its mass¢roid in 3point weighing method. On the basis of this method, the article analyzes the measurement theory of mass & centroid, and puts forward the overall design of the measurement apparatus for determining the mass & centroid of a certain tail cove.on the basis of the measurement method of mass & centroid, and combining with the configuration appearance of the product, this thesis accomplishes the design of mechanical structure to make sure the three axes of centroid only with one position.The article puts forward the specific idea for the the weighing signal acquisition system and the lifting control module, chooses several key electrical elements, then accomplishing the high-speed acquisition of three analog signals and the lifting motion control of the product bracket.Based on 3 point weighing method, the special measurement software is developed with Visual Basic 6.0 development tools, and analyzes on the key algorithm of the mass & centroid measurement as well as builds the mathematical model to complete the measurement and displaying of mass & centroid of a certain tail cover.The measuring uncertainties of mass are estimated by the GUM method. The Monte Carlo Method is applied to estimate centroid measuring uncertainties. Through measuring experiments, the functions of measurement apparatus and measuring precision are eventually validated.