Design, modeling, and experiment of a multi-degree-of-freedom pneumatic soft bionic actuator

Abstract

Drawing on the driving mechanism of biological muscles and combining the nonlinear hyperelastic characteristics of silicone rubber, a multi-degree-of-freedom pneumatic soft bionic actuator is designed, which can be used as the executing mechanism for soft robots and robotic arms. Using response surface analysis and numerical simulation algorithms, the optimal combination of structural dimensions parameters is determined with the maximum bending and torsion angles output by the actuator as the optimization objectives. Based on the idea of flexible mechanism Piecewise Constant Curvature (PCC) modeling, the kinematics equation of the actuator is derived. Analyze the equivalent motion structure of the actuator and establish a dynamic model of the actuator based on the Lagrange method. The physical model of the actuator is manufactured using rapid prototyping technology. Finally, experimental testing and analysis are conducted on the physical model to obtain the motion and dynamic characteristics curves and empirical formulas of the actuator, which are compared with theoretical and simulation results to verify that the pneumatic soft bionic actuator is feasible and effective. The above research methods, processes, and results can provide reference and inspiration for the research and implementation of pneumatic and hydraulic soft robots and gripping actuators for soft robotic arms.

Keywords:

• Biological muscles
• silicone rubber
• multiple-degrees-of-freedom
• pneumatic soft bionic actuator
• soft robot

Acknowledgments

This work was done in the Institute of Robotics at Shenyang University of Technology with support from the National Natural Science Foundation of China (Grant No. 52005344). We are grateful for this support. Besides, we would also like to thank the Department of Mechanical Engineering of the National University of Singapore for their support for the develop successfully of this work.

Code or data availability

All code or data generated or analyzed used to support the findings of this study are included within the article.

Consent to participate

Informed consent was obtained from all individual participants included in the study.

Consent to publish

The participants have consented to publish the research in the Journal of Bionic Engineering.

Disclosure statement

The authors declare that they have no conflicts of interest.

Additional information

Funding

This work was funded by the National Natural Science Foundation of China (Grant No. 52005344).