Peristaltic Pump-Based Palm-Sized Multi-Mode Pressure Supply System for Soft Robots

Soft robots have garnered considerable interest in recent years in terms of structure and functionality, while commercially viable pressure supply systems with various pressure supply modes for soft robots remain slow to progress. Hence, in this work, a palm-sized multi-mode pressure supply system based on a peristaltic pump is proposed for the first time, and precise pneumatic pressure control is achieved with a model reference adaptive control (MRAC) method based on the system dynamics. Further performance evaluation demonstrates that our system can deliver precise positive (mean error < 0.48 kPa for 0$\sim$50 kPa) and negative pressures (mean error < 0.85 kPa for −50$\sim$0 kPa) with minimal fluctuations, which outperforms the PID method. Application experiments indicate that our system can accommodate various pressure supply requirements, including controllable pressurization and depressurization, and has the potential for both pneumatic and hydraulic applications. In addition, by incorporating the MRAC method into the system, we have achieved excellent stability and high repeatability in controlling the position of a retractable soft pneumatic actuator, thus demonstrating the system's high accuracy and repeatability in pressure output. The phantom experiment of the injection soft robotic system further validates the system's diverse pressure supply capabilities for complex manipulations of soft robots.

I. Introduction

The last few decades have witnessed a boom in the structures and functions of soft robots [1], the majority of which are based on pneumatic [2] or hydraulic actuation [3]. Precise actuation relies on a reliable and precise fluid pressure supply. However, pressure supply systems have received little attention, resulting in a lack of readily available commercial solutions. Indeed, the need for researchers to establish pressure supply systems tailored to their individual soft robots leads to a substantial workload, impeding the progress of soft robotics.