基于PID闭环控制的变压边力优化设计

Variable Blank Holder Force Optimization based on PID Closed-loop Control

基于压边力成形窗口的定义和分析,提出了一种新的控制目标,并以此建立了可控压边力的比例、积分、微分(PID)反馈控制模型.采用此模型对冲压成形进行反馈数值模拟,从而得出每块分块压边板随冲压行程的最优压边力曲线,在变压边力压机上的实验验证表明:使用该压边力优化设计方法所得到的最优压边力可成功冲压出阶梯盒零件,避免在恒压边力下的起皱和破裂两种缺陷.该优化方法可以同时考虑冲压行程和压边板位置进行压边力优化,因而具有更好的鲁棒性.

Blank holder force （BHF） is one of the key parameters affecting the process of sheet metal stamping. New control objective was adopted based on the definition and analysis of BHF formability window. The PID control model was established using the new objective. Closed-loop forming simulation of step rectangle box was conducted integrating the PID model, through which the optimal BHF trajectories were determined for each separated binder. The trajectories were verified on a multipoint variable BHF hydraulic press and showed good effect to avoid wrinkling and tearing under constant BHF. The proposed BHF determination approach can conduct temporal and spatial BHF optimization simultaneously, which makes it a robust strategy.