Proposal of tendon-driven elastic telescopic arm and initial bending experiment

It is desirable to have an arm with a thin and long structure in order to observe a wide area through a narrow space for the survey at the disaster site. In addition, if the arm is lightweight and compact, there are fewer restrictions on the installation location, which leads to an improvement in the observation range. The telescopic structure has a high extension-to-contraction ratio and is a suitable structure to attain the aforementioned requirements. However, conventional telescopic arms can not avoid obstacles on the axis of extension because of high rigidity, so it is restricted to use in an open environment. In this paper, we propose an arm that controls the tip position by bending the structure with a wire by constructing a small diameter arm with a telescopic elastic body. We also examined the technical elements necessary to realize the proposed method and demonstrated the validity. It is difficult to bend in multiple directions or the whole structure by winding the wire only attached to the structure tip. Therefore, we devised a wire driving method in which bending moments are distributed as much as possible on the base side by arranging pulleys in multiple positions, and confirmed the desired motion through experiments.