铝合金电阻点焊焊接参数选择的智能化

Study on intelligent choice of parameters of resistance spot welding for aluminum alloys

通过深入分析点焊工艺过程,结合基于事例推理的特点,将铝合金点焊工艺事例属性划分为事例特征Ⅰ和事例特征Ⅱ两类。设计了铝合金相似点焊工艺事例的检索策略:在事例特征Ⅰ的约束下,以事例特征Ⅱ中包含的材质的热物理性质和板厚作为检索相似事例的依据。用模糊推理方法对检索到的相似事例库中的工艺知识、规则进行提取、总结,进而指导对新的点焊工艺事例的求解,较好地解决了铝合金点焊工艺设计中,基于事例推理时难以建立合适的模型对检索到的相似事例进行修正的难题,使点焊焊接参数的智能求解过程更符合专家的思维,过程更加灵活,具有开放性。系统应用实例及工艺实验证明此方法是可行的。

Characters of resistant spot welding case were divided into two categories,i.e.,case characters Ⅰ and case characters Ⅱ by analyzing the process in the light of attributes of case based reasoning (CBR).The following retrieval strategy from similar spot welding cases for aluminum alloys was proposed:under the restraint of case characters Ⅰ,the thermal physical properties of material and the plate thickness involved in case character Ⅱ were taken as indexes to retrieve the similar cases.The technological knowledge and rules drawn and summarized from the corresponding similar cases database by means of fuzzy inference were used to guide the solution of the new case.It is a good approach to deal with the problem that in the design of spot welding process for aluminum alloys,it is difficult to build an appropriate model to revise the retrieved similar case on CBR.The proposed intelligent choice of the spot welding parameters bears a more resemblance to the thinking mode of experts in this field.The choice process is flexible and open to environment.Application instances of the system and technological verification show that the developed approach is practicable.