Abstract: To determine the grasping points of sheet metal parts quickly and improve the degree of automation of grasping,a probability heat map-based grasping point generation and evaluation method for sheet metal parts was proposed.The single-factor probability heat maps were calculated based on the projection of sheet metal parts and end pickers to evaluate the degree of overlapping between the sheet metal parts and the end pickers,the geometric center of sheet metal parts and the surface smoothness of sheet metal parts.Then,single-factor probability heat maps were fused.The fused probability heat map was randomly meshed and the locations of highest values were selected as grasping points.Finally,finite element analysis was utilized to verify the validity of the generated grasping points.The results showed that the proposed grasping point generation and evaluation method was applicable to different grasping working conditions.The runtime of probability heat map calculation and grasping point generation was 1.58s.The maximum total deformation of the gripped Q345b sheet metal part was 7.993mm,and the maximum equivalent stress was 158.42MPa,which was smaller than the yield strength of the material of the sheet metal part.

Key words: sheet metal part, probability heat map, grasping point generation, finite element analysis

摘要： 为快速确定钣金件抓取位置,提高抓取自动化程度,提出一种基于概率热力图的钣金件抓取点生成方法。基于钣金件与端拾器投影计算单因素概率热力图,评估钣金件与端拾器重叠程度、钣金件几何中心位置、钣金件表面起伏程度;融合各单因素概率热力图对概率热力图进行随机网格划分,并以数值最高处作为抓取位置;最后通过有限元仿真验证抓取点有效性。结果表明,所提抓取点生成与评估方法可以适应不同抓取工况,单次概率热力图计算及抓取点生成需1.58 s。Q345b钣金件被抓取最大形变为7.993 mm,最大等效应力为158.42 MPa,小于钣金件材料屈服强度。

关键词: 钣金件, 概率热力图, 抓取点生成, 有限元分析