Scaling of Direct Drive Robot Arms

This paper studies the ways that the performance of direct drive serial robots changes as system size is changed. We are particularly interested in the physical laws for scaling down direct drive arms to small sizes. Using theoretical scaling analysis, we show that there is a net physical performance advantage to small direct drive arms. A key factor for direct drive robot performance is the torque to mass ratio of the actuators, . We show how varies with the scale of DD actuators, and we also calculate how the dynamic U U In Press, International Journal of Robotics Research, 15:5, June 96 093