High-robustness Carbody Parametric Modeling Based On Thought Recording

It is a very time-consuming and complex process to build a 3d model of body parts,but the real challenge is the repeated modification and iteration of the initial solution based on the analysis results of performance,structure,and process in the future,which consumes huge resources.The introduction of parametric modeling methods has alleviated this problem to some extent,but the parametric model with complex operational steps is not always updated correctly according to the designer’s expectations,and the various update errors and subsequent manual corrections cost a lot of time.Although the parametric approach has greatly improved the body design level,it is far from enough to meet the efficiency requirements of the car companies for body development in a competitive environment.For the above problems,the author of this paper cooperates with the design department of a car company to discuss the reasons and mechanisms for the failure of the 3D parametric model update of the body,in order to improve the success rate and robustness of the parametric model in the design modification and update process through innovative solutions.The parameterization of the body 3D model is essentially a recording behavior.The computer records the operator’s interaction results as input to various geometric features,which are automatically replayed during subsequent parameter changes to achieve automatic updating of the model.However,the computer only rigidly records the interaction results in the initial manual modeling process and does not record the intent and judgment of the results.Therefore,the subsequent process cannot automatically determine whether the inputs need to be changed and modified,and various update failures are generated.In response to this problem,this paper proposes a solution to replace the "interaction result" record with the "interaction intention" record,so as to improve the correctness and stability of the automatic update process.The geometric modeling process is complex and diverse,and its interaction intent is also difficult to exhaustive.However,when locked into a specific body part design,a limited number of frequently used typical interaction intentions can be determined.By secondary development,the computer can record the intents and it can improve design efficiency significantly.The project implements the above mechanism based on the Siemens NX platform.The algorithm part of this paper is completed by Visual C++ under the architecture of NX Open and UFun.The system integration and feature record are completed by knowledge fusion technology.The final test of the program is completed in the OEM,and the mechanism of this paper shows obvious advantages compared to the traditional method.The main innovation of this paper is to replace the "interaction result" record with the "interaction intention" record,so that the computer can realize the automatic judgment based on intention in the process of model modification and update.It solves various unforeseen conditions in the process of model modification.The test in the OEM fully proves this.Although the research of this paper is based on Siemens NX,its problems are common,and its ideas and methods are useful.