A Back-Drivable Rotational Force Actuator for Adaptive Grasping

Abstract

In this paper, a back-drivable and miniature rotary series elastic actuator (RSEA) is proposed for robotic adaptive grasping. A compact arc grooves design has been proposed to effectively reduce the dimension of the RSEA system. The elastic elements could be reliably embedded in the arc grooves without any additional installation structures. The whole RSEA system is characterized as compact, miniature, and modular. The actuating force is controlled via a PI controller by tracking the deformation trajectory of the elastic elements. An underactuated finger mechanism has been adopted to investigate the effectiveness of the RSEA in robotic adaptive grasping. Results reveal that the underactuated finger mechanism could achieve adaptive grasping via the RSEA in a back-drive approach without the requirement of a fingertip force sensor. The RSEA could also exhibit an actuating compliance and a self-sensing characteristic. The actuating compliance characteristic helps in in guaranteeing the safety of human–robot interaction. The RSEA could estimate the external disturbance due to its self-sensing characteristic, which has the potential to replace the fingertip force sensor in grasping force perception applications.

Non-back-drivable clutch based self-locking mechanism of prosthetic joint to improve manipulation stability

“…Researches focusing on how to improve NBDC performance have concluded five optimization directions ( Chu et al, 2008 ; Controzzi et al, 2010 ; Controzzi et al, 2017 ; Montagnani et al, 2015b ; Hu et al, 2021 ; Wu et al, 2023 ): (1) Low cost. In order to meet the large-scale production and implementation of self-locking mechanisms, the cost of related components need to reasonably controlled ( Liu et al, 2021 ) while ensuring the performance and quality ( Mota et al, 2023 ).…”

“…At the same time, there is a certain amount of free travel in the self-locking process, resulting a small deviation at the load end. Xiaofeng Wu et al ( Wu et al, 2023 ) proposed a compact arc-groove self-locking mechanism with two linear springs embedded in the arc grooves, eliminating the need for additional mounting structures. The whole system is compact, small, and modular, enabling underdriven finger mechanisms to achieve adaptive gripping.…”