Kinematics Modeling of Soft Manipulator Interacting with Environment Using Segmented Variable Curvature Method

In this paper, a novel kinematics model based on segmented variable curvature (SVC) method is proposed to describe the deformation of soft manipulator under the condition of environmental contact. Firstly, the variable curvature (VC) framework is used to the spatial backbone curve, which is to discrete the soft manipulator into tangent arcs with different curvatures. When the contacts with surroundings occur, the contacted arcs are further divided into several separate sub-segments at the contact points. Then, combining kinematics and statics of all the segments, the model of soft manipulator is established under environmental constraints. The proposed model inherits the generality of the continuous VC method, and resolves the complex contact problem with environmental constraints. Finally, simulations and experiments are conducted to verify the effectiveness of the proposed SVC method under contact conditions. The results show that compared with the traditional VC method the proposed model can obtain higher accuracy in describing contact segment deformation under contact constraints without knowing the contact force in advance.