Cooperative force control in carrying an object by two humans

Robots are expected to be human-friendly and to execute tasks cooperating with humans. Control system for the robots should be constructed so as to work adapting with human characteristics. In this paper, human characteristics in a cooperation task by two humans are analyzed and it is shown that the human performance can be expressed by impedance control. The authors also investigate the characteristics based on passivity. The results show that the passivity is high in a few seconds after the movement commences and before the movement ceases, and is low during high velocity interval.