Maneuverability of master control devices considering the musculo-skeletal model of an operator

In this paper, maneuverability measure of master control devices considering the musculo-skeletal model of operators is proposed. The original maneuverability measure of master arms considering the operator dynamics is extended by introducing a muscle tension space instead of the joint torque space of an operator so that the maneuverability is evaluated under a constant muscle stress condition which is related to muscle fatigue. Unidirectionality of muscle tension forces as well as the gravity effects acting on the master device and the operator arm are explicitly considered to get a correct evaluation. As a numerical example, the effect of a movable armrest installed on a master arm is evaluated based on the proposed measure. It is shown that the armrest is effective to reduce muscle fatigue by not only lowering the gravity loads for the operator but also reducing the gripping force necessary to maneuver the device. Experiments are also conducted to verify the result of this numerical example.