Study Of Mapping Relationship Between Geometric Parameters And Characteristics For Precise Electro-hydraulic Servo Valve

In view of the advantage of electro-hydraulic servo system, the control system of aircraft often uses the electro-hydraulic servo system. As a key component of electro-hydraulic servo system, the electro-hydraulic servo valve largely determines the performance of electro-hydraulic servo system and the success or failure of aircraft mission. Precise electro-hydraulic servo valve used in aerospace field is a kind of high-tech product, as its complicated structure, high precision and application under worse environment. Influenced by all kinds of geometric factors, such as the machining and assembly precision of the parts and components, the characteristics of precise electro-hydraulic servo valve is rather difficult to be controlled. It results in rather low pass rate and higher rework rate and more costs of the resources as well. The low production ability of precise electro-hydraulic servo valve has been become one of the important factors to restrict the development of aerospace career in our country. Therefore, that how to improve the pass rate and production efficiency of precise electro-hydraulic servo valve and avoid abundance of repair works becomes one of difficult problem that solve urgently in related manufacture enterprises.Precise electro-hydraulic servo valve product takes multiple characteristics as manufacturing request. The effective way to ensure and improve its pass rate is to improve the machining and assembly precision of the parts and components and the precision stability. However, in view of the limitations of the machining equipment and technology in the existing producing conditions, it is unrealistic to use the above method for it increases the costs on production exponentially. Therefore, it makes lots of sense on industrial production that the effective way is researched by utilizing modern calculation methods to raise the pass rate and production efficiency of precise electro-hydraulic servo valve product.Precise electro-hydraulic servo valve product, which is the key part in the guidance system in aeronautics industry, is taken for an example. The current situation of research on related technology of electro-hydraulic servo valve, data mining and artificial intelligence method at home and abroad is analyzed at first. Based on the determination of the primary or secondary relationship of each geometric factor for characteristics of precise electro-hydraulic servo valve, deep researches have been done on the method of the prediction of the system characteristics, the interval estimation method of geometric factors which have an influence on the multiple characteristics of the system. Moreover, the synthetic analysis system of precise electro-hydraulic servo valve product has been developed. It is of great significance for research results to optimize the manufacture requirment and increase the rate of finished products and the production efficiency of precise electro-hydraulic servo valve product. The research work in details is as follows:(1) The primary or secondary relationship of each geometric factor for characteristics of precise electro-hydraulic servo valve product has been studied. Grey correlation analyzing method is adopted to analyze the actual tested data to ascertain the major factors and minor factors of each characteristics of precise electro-hydraulic servo valve product. Rough set strategy method is combined to develop the feature extraction model of multiple geometric factors of precise electro-hydraulic servo valve product in order to control the characteristics by controlling the major geometric factors which have an influence on the characteristics of precise electro-hydraulic servo valve. Meanwhile, the unrealistic problem on dealing with many input variables has been settled when developing the mathematical model of precise electro-hydraulic servo valve product. The characteristics prediction model is developed by using the major geometric factors which have been ascertained to decrease the number of dimensions of the input space, simplify the modeling process and thus improve the modeling precision. It has laid a foundation for the whole research work.(2) When controlling geometric factors affecting the characteristics of precise electro-hydraulic servo valve reasonablely, the case that precise electro-hydraulic servo valve product after assembly is unqualified occurs occasionally. In view of the limitations of the traditional system modeling method on the modeling of complex systems, and based on the effective information selected by data mining and the correlated model between multiple geometric factors and characteristics of precise electro-hydraulic servo valve product, the characteristics prediction model of precise electro-hydraulic servo valve product is explored and studied by using artificial intelligence algorithm such as neural network, support vector machine and fuzzy inference technology. The mathematical model between multiple geometric factors and characteristics of precise electro-hydraulic servo valve product has been set up so that precise prediction of the characteristics of precise electro-hydraulic servo valve product is realized. The results have proved the effectiveness of the algorithm set up by data modeling and simulation, improving the characteristics prediction model and algorithm of the system, and analyzing and comparing the actual testing results and the predicting figures by utilizing modernized numerical analysis method. Whether the precise electro-hydraulic servo valve product is qualified or not can be directly ascertained by analyzing the prediction results and the unqualified components can also be got rid of so that the repetitive assembly and disassembly, and testing work are prevented and the producing efficiency can been improved. (3) As for the unqualified components, it has the pertinence on the rework of the parts and components to research that how to determine the range of multiple geometric factors which affect the characteristics of precise electro-hydraulic servo valve product. Moreover, as for the precise electro-hydraulic servo valve products which have specific performance requirements, the design range of geometric factors of the parts and components can be got. Obviously, the research achievement will provide both theoretical and technological support for product designers and manufacturers. It is also a challenge in the product design and production of precise electro-hydraulic servo valve product. The effective information is extracted based on data mining and by the thought of reverse engineering, proper optimized design method and intelligence algorithm are adopted to develop the interval estimation model between the multiple characteristics and geometric factors of the precise electro-hydraulic servo valve product. The interval estimation of geometric factors of precise electro-hydraulic servo valve product is realized. The interval values of multiple geometric factors can be obtained utilizing the interval estimation model which has been set up.(4) Many departments in enterprises, such as the designing department, manufacturing department and quality inspection department, etc. are involved in the production of precise electro-hydraulic servo valve product. It is a major approach for the improvement of the producing efficiency of precise electro-hydraulic servo valve product to study and develop synthesis analysis system of precise electro-hydraulic servo valve product system so as to increase the coordination capabilities among departments and realize rapid exchanges of products'information. Based on the above research achievements, SQL is adopted to develop the information data base for precise electro-hydraulic servo valve product, MATLAB is utilized to calculate and simulate the data, and VC helps achieve visualization operation. The research of the interface technology among SQL, MATLAB and VC to develop the synthesis analyzing system platform of precise electro-hydraulic servo valve product will provide a reliable test method for the primary or secondary relationship of each geometric factor for characteristics of precise electro-hydraulic servo valve product, characteristics prediction and the reverse interval estimation for geometric factors. It offers a new method to improve the rate of finished products of precise electro-hydraulic servo valve product and meanwhile it plays an important role in promoting the application and development of modernized modeling method in the field of engineering and technology.The research works in this paper of mapping relationship between geometric parameters and characteristics for precise electro-hydraulic servo valve, include:major factors and minor factors analysis for characteristics, prediction method of the characteristics and the interval estimation method for multiple geometric factors, have been applied preliminary to a precise electro-hydraulic servo valve, which is the key part of the hydraulic actuator in the guidance system in aeronautics industry.