Methodology For Elimination Of Negative Actions Of Technical System Based On Function Analysis

The key of product innovation is to find and solve the conflicts in the design process.TRIZ theory is a systematic design theory used in product innovation design,which put forward the theoretical methods to solve conflicts,including invention principle,separation principle,76 standard solutions and so on.Due to the complex interaction among the internal subsystems of products,designers often encounter many interrelated conflicts in the design process,which makes the classical TRIZ theory face great challenges in resolving conflicts.However,conflicts are external representations caused by negative actions within technical systems.Therefore,this paper studies from the internal cause of conflicts,that is,negative actions.With the goal of eliminating the negative actions in the technology system,it conducts in-depth research on negative actions from three aspects: problem impact priority,further causal analysis and problem solving,so as to find a new path to solve the conflict.The main studies of this paper are as follows:A method of ranking the influence degree of negative action component unit problems is proposed.On the basis of the function analysis,the digital calculation of the influence relationship between components is realized with the help of DEMATEL method.Based on the structural composition of the component unit,the center degree,cause degree and problem influence degree of the negative action component unit are defined,and the ranking principle of the negative action component unit considering the problem influence degree is established,thus the priority order for resolving negative action component unit is determined.A causal analysis method based on primitive model and minimum cut set is proposed.From the perspective of functional realization,the functional area map is divided.By introducing the primitive model of extension,the components and the relationship between components in the problem functional area are normalized by using the primitive model,so as to provide the information of component characteristics,corresponding value and function realization for further causal analysis to dig deep causes.At the same time,the calculation of minimum cut set is applied to the process of selecting key reasons in causality analysis,the selection principle of key reasons is formulated,and the logical calculation of the process of selecting key reasons is realized.A case push method of invention principle based on attribute parameter similarity is proposed.Based on the basic principle of convenient description of product characteristics,39 engineering parameters are classified.In order to reduce the abstractness of transforming the original understanding into domain solution,the invention principle is expanded by cases.By standardizing the expression form of problems and cases,the weight of attribute parameters of case retrieval is calculated based on Analytic hierarchy process(AHP),and the cases which are similar to the problem are sorted out with the help of cosine similarity algorithm.the conceptual design scheme of problem solving is deduced by analogy with similar cases.According to the above research content,a method of eliminating the negative actions of technical system based on function analysis is proposed.This method is applied to the engineering design of the submarine cable reaction cone cutting device.Aiming at the problem of low surface quality of the reaction cone when cutting submarine cable with milling cutter,a conceptual design scheme of the process of eliminating negative actions is established,so as to the feasibility of the proposed method is verified.