Simulation of Dynamic Characteristics of Manipulator Equipped with Passive Joint and Low-Rigidity Link

In this paper, we describe the dynamic characteristics of a two link maniqulator which equipped with a passive joint and a low-rigidity link. This manipulator is composed of high-and low-rigidity tinks which are connected by a passive joint and an electromagnetic brake. The purpose of this structural feature is to harness the elastic strain energy of the low-rigidity link and the inertia of the system itself. >From the viewpoint of energy efficiency, the performance of this manipulator was evaluated analytically in terms of the energy efficiency index, i.e., the ratio of the kinetic energy of the payload to the work load of the driving motor. Also the carrier efficiency index was estimated as the ratio of the energy efficiency index to the working time required. As a result, in terms of working efficiency, this manipulator was compared with a typical two-link horizontal manipulator in various conditions of motion. It was clarified that the energy efficiency index strongly depends on the initial angle of the passive joint