Abstract
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.
Abstract (translated)
符合要求的抓握手具有适应性和安全性，因此在实际应用中，如工业或物流场景，对无结构抓取吸引了相当的注意力。然而，准确构建数学模型描述这种符合要求的抓握手，如Fin-Ray抓握手，的双向形状变形和接触力的关系，迄今为止仍然停滞不前。为了解决这一研究空白，本文提出了一种实验验证过的通用双向力量-位移数学模型，基于共旋转概念，赋予这种抓握手具有内在的力量感知能力，并提供更好的设计优化的见解。本文第一部分介绍了共旋转方法的基本理论，其中可以任意大的形状变形建模。其内在原理使理论建模可以考虑各种配置类型和关键设计参数，只需要少量的假设。此外，提出了一种力量控制算法，提供在外部力量下准确的位置估计，只需要轻微的计算负载。该方法的性能通过与有限元分析的比较进行了实验验证，研究了四个关键设计参数对抓握手性能的影响，从而促进了系统级设计优化。本文第二部分展示了力量感知能力和代表性共旋转建模参数对模型精度的影响，将其发布在Google Drive中。
URL
https://arxiv.org/abs/2303.12987
