Dynamic modeling and Control of a Soft Robotic Arm Using a Piecewise Universal Joint Model

The Piecewise Constant Curvature (PCC) assumption is the most widely used in the modeling and control of soft robots. However, a limitation of PCC models lies in accurately describing the deformation of a soft robot when executing dynamic tasks such as operating under gravity or interacting with humans. This paper introduces a new methodology for dynamic modeling and control of a multi-segment soft arm in the 3D space where each segment undergoes non-constant curvature deformations. In this framework, the soft manipulator is modeled as a series of segments, with each one represented by two stretchable links connected by a universal joint. Furthermore, we devise and analyze a controller for motion control in the configuration space with unknown load. The controller is implemented on a four-segment soft robotic manipulator and validated in a range of dynamic trajectory tracking tasks.