Kinematic Analysis of Novel Soft Robotic Arm Based on Virtual Work Principle

In order to improve the motion accuracy of a novel soft robotic arm with extensive degree of freedom, the kinematic model is established. Firstly, a soft robotic arm composed of two single modules is designed. Each single module contains two extension pneumatic silicone actuators (EPSAs). Secondly, the kinematic model of the EPSA is established based on the superelastic material model, the geometric relationship and the virtual work principle. Then, the kinematic model of the single module is established based on the kinematic model of the EPSA and the constant curvature assumption. Next, the kinematic model of the soft robotic arm is established by using the Frenet frame. Finally, the numerical simulation is carried out based on the Obtained kinematic model. In order to verify and modify the above kinematic model, the numerical experiment is carried out based on the finite element method. The results of the two numerical experiments show that the modified kinematic model is almost identical to the finite element model, which indicates the feasibility of this modeling method and the accuracy of the established kinematic model. This study provides the necessary kinematic foundation for the control of a soft robotic arm.