| With the intensification of market integration,enterprises are forced to launch the customized new product to meet the requirements and product diversity of customers for occupying the inside track,thus making quickly responding to the fierce market competition.Additive Manufacturing,which has the relatively strong development capability,has become the research hotspot recently.3D printing and rapid tooling(rapid tooling,RT)are the main technical support of AM,and Vacuum Casting(Vacuum Casting,VC)is the most widely used in RT,Compared with its counterparts,widely applied VC has positive promotion effect on product innovation,shortening development period and developing green production.However,the quality control of VC product depends largely on the experience of workers and its low automation has started to restrain the further development of VC technology.Therefore,researching new quality controlling method for VC product and changing the traditional pattern of depending largely on the experience of workers has important practical value for improving the productivity of VC product and the developing capability for new product.In order to improve the quality of VC products,taking the VC forming process as the research object and the technological process as the main line,the mechanism of VC forming process is studied based on computer graphics,visualization technology and intelligent control theory and so on.The current quality defects of VC products and the defect formation reason in the forming are summarized,and the key process parameters affecting product quality also are analyzed.This paper studies the obtaining method of geometrical characteristics of the mold cavity,and establishes a method for obtaining the geometric information of the mold cavity based on the product STL model.On this basis,the intelligent control model of product quality is studied,and the intelligent control system of product quality combined CBR(Case Based Reasoning,CBR)with Rule Based Reasoning(Rule Based Reasoning,RBR)is established.Finally,the intelligent control system of product quality is studied based on the theory,method and control technology,and the correctness and effectiveness of the above methods are verified by experiments,which provides a feasible method to realize intelligent decision making and intelligent control of VC products.1.Aiming at solving the problems of mainly dependence of VC forming processon workers,long mold test period and unstable VC product quality,some common encountered defects of VC product and VC product forming process are analyzed.Some critical factor influencing on product quality and the urgent problem need to be tackled are proposed.2.Studying the acquisition method of mold cavity geometric feature,a reverse geometrical intersection algorithm is proposed.Based on this algorithm,the voxelization model for describing the model cavity is built by slicing and doing voxel discretization for STL model.And geometrical information of mold cavity such as product volume,surface area,average wall thickness are obtained based on the voxelization model,thus proving a feasible method for obtaining the geometric feature of VC product instantly.3.Aiming at solving the problem that VC product quality control depends largely on experience of workers and resulting in unstable product quality and the problem of high cost.Summing the experience of operators and based on the passed records,the hybrid intelligent decision model of VC forming process and quality control is built by using the reasoning method combining Case Based Reasoning(Case Based Reasoning,CBR)and RBR to realize the intelligently revising VC product defect,thus proving an effective method for intelligent control of product quality.4.Based on intelligent control model of product quality and under the environment of Microsoft Visual Studio 2010,reasoning system mixed CBR and RBR is established.The forming experiments of some electric appliance cover is conducted to verify the correctness and feasibility of above-mentioned theory and methods. |
