PURPOSE: To control respective arms dynamically with respect to acceleration, velocity and position so that an operator can operate a robot with presence, by controlling the impedance, inertia, viscosity and elasticity of the respective arms.

CONSTITUTION: An operational environmental model represented by the mass, viscosity and rigidity of a master arm and an working environmental model represented by the mass, viscosity and rigidity of a slave arm are adapted to communicate to each other through a computer so that the apparent dynamic properties of both arms coincide with each other. Thus, presence can be given to an operator in the operation of a robot.