Software Design And Study Of Process Intelligence Expert System In NC Camshaft Grinding

Grinding is an important processing method in machinery manufacturing. As the final processing of grinding, it directly determines the quality of the finished workpiece in most cases. The common problems that grinding faced currently are that it is heavily dependent on operator experience, and choosing the grinding process plans are still focus on the traditional "test cut" method and "experience" law, which lead to low efficiency and poor flexibility of processing. Camshaft as a critical component of motor, engine, national defense and other industries, its processing accuracy and efficiency directly affects the quality, life and energy efficiency standards about the engine and related products. Therefore, the article aims to study camshaft CNC grinding, analyze grinding process modeling and process plan optimization methods, the error compensation analysis and the status and development trends of grinding database, develop the camshaft CNC grinding intelligent expert system, including the grinding process intelligent optimization module, intelligent reasoning module, grinding error analysis and intelligent compensation and grinding process database. The research work mainly includes:(1) The camshaft CNC grinding mathematical model is amended and established partly. The effect about different grinding allowances and wheel radius to the errors of the mathematical models of X-C axis coordinate is analyzed and compared, and the revised mathematical models are set up respectively; a general mathematical model of cam lift conversion based on the least square method is established.(2) A whole frame of camshaft CNC grinding intelligent expert system is established. The overall requirements and design ideas of camshaft CNC grinding process intelligent expert system are analyzed; the system operation framework and main modules are established, namely intelligent optimization module, intelligent reasoning module, error analysis and intelligent compensation module; the camshaft CNC grinding process database system’s functional modeling is put up, and the overall structure of the database system and sub-library structure are defined.(3) The grinding process intelligent optimization model is established and experimental verified. The characteristics properties selection in camshaft CNC grinding is realized using RS (Rough set), and a new R5model is proposed; the subjective weight calculation of characteristic properties is achieved using AHP (Analytic Hierarchy Process), the combination weight of feature attributes is gotten by defining the combination weighting method; a hierarchical filtering mechanism with a three-level filtering of feature weight is established; the calculation method of local similarity about four feature attributes is defined, they are value-based, fuzzy logic-based, independent and enumeration types, and the calculation of examples’ overall similarity is realized; the reuse of examples is achieved by using the comprehensive evaluation factor based on fuzzy comprehensive evaluation model; take a type of camshaft’s grinding process as an example, the validity of grinding intelligent optimization model is proved.(4) The grinding process intelligent reasoning model is established and verified by experiment. The grinding process intelligent reasoning model is established integrating rule-based reasoning and genetic neural network algorithm, which can reason/map out a complete grinding process. Mixed reasoning with positive and negative position, an integrated sort of confidence and activity to realize conflict resolution, and the path tracking method to achieve an explanation of the reasoning process are used in reasoning strategy. The uniform design experimental method is used to arrange camshaft CNC grinding experiments, and volume of training samples have gotten; the automatic mining on the field of CBN grinding wheel dressing with diamond grinding wheel is implemented in camshaft CNC grinding based on RS theory.(5) The grinding error analysis and intelligent compensation model is established and verified by experiment. By the lift error analysis, a combined effect about a variety of factors on the cam contour accuracy is found, and a camshaft CNC grinding error analysis strategy is put up; based on the strategy and results of error analysis, a compensation strategy about a virtual profile construction by building virtual lift is put forward; for the overall smoothness of the original lift or virtual lift is low, a quadratic smoothing treatment method is used to adjust them; take a type of camshaft’s grinding process as an example, the validity of grinding error analysis and intelligent compensation model is proved.(6) Software implementation and experimental validation are taken on camshaft CNC grinding intelligent expert system. The corresponding programming and software interface development are carried out for intelligent optimization module and reasoning module of the grinding process, error analysis and intelligent compensation module, to achieve the overall integration of each functional module; take a type of camshaft’s grinding process as an example, the validation the rationality and effectiveness of camshaft CNC grinding intelligent expert system is proved.