Design, Modeling, and Control of Soft Syringes Enabling Two Pumping Modes for Pneumatic Robot Applications

Pneumatic actuation is important in robotic applications, such as manipulating objects in interaction scenarios using pneumatic grippers and suction cups. However, traditional pneumatic actuation approaches, including industrial pneumatic systems and syringe pumps, suffer from limitations such as bulky systems, noisy operation, and inflexible pressure modulation, which limit their practicality for daily use. To address these challenges, we proposed a novel soft syringe (SS) and its corresponding SS pump. Moreover, we developed a two-mode pumping mechanism (direct and continuous pumping) for both positive and negative pressure outputs, enabling flexible pressure modulation. A detailed description of the SS's design, modeling, control, and performance is provided. Additionally, a keyframe model is introduced to simplify the modeling of pressure dynamic response. The SS showcases the benefits of low friction, high operational frequency (6.5 Hz), low noise (55.6 dB), and sufficient pressure range (-0.08 MPa to 0.15 MPa). Experimental results demonstrate the promise of the proposed approach for diverse pneumatic end-effector actuation and control with excellent modulation and scalability in human-centered scenarios.