Planning of knotting manipulation

Abstract

Deformable linear objects, such as tubes, cords, wires, and threads are used widely; not only for data transmission or for object transportation but also for fixing or packing of objects, including themselves. Such manipulative tasks include knotting. On the other hand, self-entwining of linear objects should be avoided during their manipulative processes. Therefore, it is important for linear object manipulation to analyze knotting or entwining. The chapter presents a planning method for knotting/unknotting manipulation of deformable linear objects. Topological states of a linear object are represented as finite sequence of crossings and two attributes of each crossing. Transitions among the topological states are defined. It generates possible sequences of crossing state transitions, that is, possible manipulation processes from the initial state to the objective state. The chapter proposes a method for the determination of grasping points and their moving direction to realize derived manipulation processes and introduces criteria for the evaluation of manipulation plans to reduce the candidates of manipulation plans.