通过监测电极位移的模糊控制铝合金点焊

Fuzzy control for resistance spotwelding ofaluminum alloy by monitoring electrode displacement

关键词:  点焊  铝合金  模糊控制  熔核尺寸  电极位移

Key words:  spot welding  aluminum alloy  fuzzy control  nugget formation  electrode displacement

摘要:

利用热弹塑性有限元来仿真研究铝合金的点焊过程,分析了焊接电流和电极挤压力对点焊质量的影响。研究了电极位移与焊接电流和挤压力间关系,证明电极位移表征了点焊质量,只要电极位移控制在一个合适的范围内,就能得到理想的点焊质量。在此基础上,提出监控电极位移,利用模糊控制方法,实时改变点焊的电流,从而控制点焊熔核尺寸,达到良好的点焊质量。由于模糊控制的引入,极大地扩大了点焊对挤压力等的适应能力,方便了点焊初始参数的选取。

Abstract:

A thermo-elastic-plastic finite element method is used to simulate the process of spot welding, which analyzes the effect of the welding current and squeezing force on the properties of spot welding , and shows the electrode displacement presenting the properties of spot welding .It is proved that the sound nugget can be achieved when the electrode displacement is controlled in an acceptable scope .Furthermore , a fuzzy control method is proposed that the welding current is modified in real time by monitoring electrode displacement.By using the fuzzy control method, the nugget size of spot welding is controlled in real time , and the properties of spot welding are acceptable.It is convenient to choose the initial welding parameters for achieving the sound resistance spot welding by using the fuzzy method proposed in this paper.