Kinematic modeling and control of a novel pneumatic soft robotic arm

A novel soft robotic arm (SRA) composed of two soft extensible arms (SEAs) and a soft bendable joint (SBJ) for space capture systems is presented in this paper. A diamond origami pattern was applied in the design of the SEAs, and large deformations of the SEAs in positive pressure were simulated using the nonlinear finite element method. A kinematic model of the SRA using the Denavit–Hartenberg method based on the assumption of constant curvatures was proposed. A closed-loop model-free control system based on a PID controller was developed using real-time data from a vision sensor system. The kinematic model and closed-loop model-free control system are experimentally evaluated on an SRA prototype by four experiments. The experimental results demonstrate that the derived kinematic model can finely describe the movement of the SRA and that the closed-loop control system can control the SRA to reach the desired destination or trajectory within an acceptable error and performs well in long-term repeated operations.