Determination of parameters in compound Fill sphere model for haptic interaction

The compound Fill Sphere Model (cFSM), which is an extension of common Fill Sphere Model, is widely used in real-time haptic interaction with deformable body. Comparing with finite element based model, the simplicity and efficiency are advantages of cFSM. However, determining implicit parameters of cFSM is a difficult task since a vivid deformation should be attained during haptic interaction. In this paper, to improve the simulation precision, parameter matrices of the cFSM are identified through an analytical method for the first time to our best knowledge. After deriving parameter matrices by linearization, the stiffness matrix, damp matrix and mass matrix of the cFSM are obtained by minimizing errors between stiffness matrix of the Finite Element Model (FEM). In order to evaluate the performance of derived parameters, comparative experiment has been conducted between the cFSM and FEM. Additionally, based on the derived parameters, a real-time haptic interactive scenario is constructed to validate the performance of deformation simulation.