Dimension Optimization of Pneumatically Actuated Soft Continuum Manipulators

Soft continuum manipulators exhibit promising applications over traditional rigid manipulators because of their compliant bodies. However, the unexpected phenomenon due to the gravity, called instability, makes it challenging for design, modeling and control. In this paper, we design a two-section pneumatically actuated soft continuum manipulator, containing three-chambered pneumatic actuators in each section and investigate the optimal Length to Diameter Ratio (LDR) of the manipulator by Finite Element Analysis (FEA). We introduce a new measure variable - workspace ratio (WR) - to examine the workspace as well as the instability and we can determine our optimal LDR value based on this variable. A soft manipulator is then fabricated and experimentally tested. The experimental results are in good agreement with model simulation. Results show the optimal value of LDR is at the maximum LDR, which is about 4.71 for one-section soft manipulator and 3.91 for two-section soft manipulator. This can be the guidance to the multiple-section soft manipulator design for further applications.