A drive unit 10A is provided with: a parameter storage device 30A for storing the dynamic characteristic parameters of a first and a second virtual object that are affected by a virtual interactive force λＲ, said parameters causing a driving force that corresponds to a target driving-force command τd to act upon an environment 50; a force-measuring instrument 35 for outputting the measurement result of the driving force as a measured driving-force value τs; an admittance model computation device 31A for outputting the displacement of the first virtual object calculated by computation in accordance with the stored dynamic characteristic parameters, the target driving-force command τd and the measured driving-force value τs; and a position control drive device 33A that operates following a target position command. The force-measuring instrument 35 is arranged between the position control drive device 33A and the environment 50, and the target position command corresponds to the displacement of the first virtual object outputted from the admittance model computation device 31A. The drive unit 10A has both the advantages of high backdrivability and the advantages of low backdrivability.
DRIVE UNIT ADOPTING ADMITTANCE CONTROL