Manipulation of deformable linear objects with knot invariant to classify condition

In this paper, we propose a description method of conditions of rope using a topological model and knot theory. And, we also propose a recognition method to obtain the structure of rope from visual information obtained by the CCD cameras when a robot manipulates a rope. There are many deformable objects such as papers, clothes, and ropes in life space of a person. Robots need skills to manipulate deformable objects, in order to take active parts in such space. However, it is difficult for robots to manipulate deformable objects well and possibility of failure to operate deformable objects cannot be denied. Therefore theoretical framework of error recovery for deformable object manipulation is required. For error recovery system, it is necessary to abstract profitable data from deformable objects, which are hyper degrees of freedom structures. Finally, effectiveness of methods are confirmed by experiments.