A Pneumatic-Actuated Flexible Robotic Arm With Rigid Backbone for High-Precision and Safe Manipulation
Xuanyi Zhou, Changqu Wu, Shibo Cai, Guanjun Bao
Abstract
Soft robots enable promising potential terms of safety and flexibility in interacting with the environment. However, soft robots are impeded by insufficient stiffness owing to inadequate mechanical properties. While cable-driven robots, which are widely applied in medical scenarios, such as minimally invasive surgery, benefit from precise motion control compared to soft robots. To maintain flexibility while improving control accuracy and output capacity, a rigid-flexible converged robotic arm is designed in this article using a foldable actuator that combines the benefits of soft and cable-driven robots. The analysis of functional principles and modeling is conducted on the flexible actuator and the rigid-flexible converged robotic arm, respectively. First, the mathematical models of the foldable actuator and the flexible arm are established. Then, an experimental platform and prototypes are built for physical study. The experiments demonstrated that the proposed rigid-flexible converged robot arm has noteworthy flexibility and control performance with rigidity as well as substantial output force, which is able to achieve a maximum output torque of 2300N <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\cdot$</tex-math></inline-formula> mm and single joint closed-loop control accuracy of 0.15 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> . The exceptional precision of this robot sets it apart from traditional soft robots, showcasing its capacity for highly accurate and precise movements across a wide range of applications. The safety of the robotic system was further validated through human–robot interaction safety experiments.