Modeling of Hydraulic Soft Hand with Rubber Sheet Reservoir and Evaluation of Its Grasping Flexibility and Control

In situations where robots work alongside hu- mans, they must be capable of responding flexibly to unexpected external forces. To address this challenge, researchers have conducted numerous studies on soft robotics. However, most of the soft hands studied so far are powered by pneumatic pressure and can only exert pressure up to a several hundred kPa, resulting in low output. To solve this problem, we have developed a hydraulic soft hand in our previous research. In this paper, we derive the relationship between driving pressure, bending angle, and grasping force of a soft hand with a reservoir to evaluate the effect of a rubber sheet reservoir. Additionally, we experimentally show that the soft hand provides grasping flexibility when angle control is applied using the model proposed in this paper.