Compliant grippers, owing to adaptivity and safety, have attracted considerable attention for unstructured grasping in real applications, such as industrial or logistic scenarios. However, accurate construction of the mathematical model depicting the bidirectional relationship between shape deformation and contact force for such grippers, such as the Fin-Ray grippers, remains stagnant to date. To address this research gap, this article devises, presents, and experimentally validates a universal bidirectional force-displacement mathematical model for compliant grippers based on the co-rotational concept, which endows such grippers with an intrinsic force sensing capability and offers a better insight into the design optimization. In Part 1 of the article, we introduce the fundamental theory of the co-rotational approach, where arbitrary large deformation of beam elements can be modeled. Its intrinsic principle enables the theoretical modeling to consider various types of configurations and key design parameters with very few assumptions made. Further, a force control algorithm is proposed, providing accurate displacement estimations of the gripper under external forces with minor computational loads. The performance of the proposed method is experimentally verified through comparison with Finite Element Analysis, where the influence of four key design parameters on the gripper s performance is investigated, facilitating systematical design optimization. Part 2 of this article demonstrating the force sensing capabilities and the effects of representative co-rotational modeling parameters on model accuracy is released in Google Drive.
翻译:适应性和安全性促使软式夹持器在实际应用中受到了广泛关注,如工业或物流场景中的非结构化夹持。然而,如Fin-Ray型软式夹持器之类的夹持器的形状变形和接触力之间的双向关系的数学模型的精确构建仍然停滞不前。为了填补这一研究空白,本文提出了一种基于共转概念的通用双向力-位移数学模型,为软式夹持器赋予了固有的力感知能力,并提供了关于设计优化的更好的洞察。在本文的 Part I 中,我们介绍了共旋方法的基本理论,其中可以对梁元素的任意大变形进行建模。其固有原理使得理论建模可以考虑各种类型的配置和关键设计参数,并且只做了非常少的假设。此外,提出了一种力控算法,提供了外部力下夹持器的精确位移估计,计算负载很小。所提出的方法的性能通过与有限元分析的比较实验验证,其中调查了四个关键设计参数对夹持器性能的影响,有助于系统的设计优化。本文的 Part II 展示了共旋建模的力感应能力以及代表性共旋建模参数对模型准确性的影响。