Mass spring model for non-uniformed deformable linear object toward dexterous manipulation

Manipulation for deformable object is difficult in robotics. The deformation of the deformable object is not the same, despite the same manipulation. This is due to the difference in the object characteristics, which depend on knitting, material, etc. This leads to difficulties in the motion planning. We propose a method that estimates the string model by comparing the real string movement and simulated string movement in a certain manipulation repeatedly by trial and error. This method realizes several manipulations using unknown strings. But feasible range was limited to uniform strings. In this paper, we proposed string model for representing various kind of string. This model assumed that mass distribution is not uniform and bending properties is different depending on extraction and contraction. Where this model was applied to several non-uniform string and uniform string, we confirmed that the proposed model can express the actual string movement.